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Home My WebLink AboutRS_Topgolf_Renton_Drainage_Technical_Information_Report_190614_v1June 14, 2019 Prepared for: City of Renton 1055 South Grady Way, 6th Floor Renton, WA 98057 Reviewed by: Jenelle Taflin, P.E., LEED AP Principal jtaflin@navixeng.com TECHNICAL INFORMATION REPORT TOPGOLF RENTON RENTON, WASHINGTON PRE LI MI N A R Y NAVIX TopGolf Renton – Renton, WA TOC TABLE OF CONTENTS SECTION PAGE PROJECT OVERVIEW ..................................................................................................................................... 1 1. DESIGN CRITERIA.............................................................................................................................. 1 2. EXISTING CONDITONS ...................................................................................................................... 1 3. PROPOSED CONDITIONS .................................................................................................................. 5 4. TIR WORKSHEET ............................................................................................................................. 10 5. SITE LOCATION ............................................................................................................................... 16 6. DRAINAGE BASIN, SUBBASINS, AND SITE CHARACTERISTICS ........................................................ 17 7. SOILS .............................................................................................................................................. 18 CONDITIONS AND REQUIREMENTS SUMMARY ........................................................................................ 19 OFF-SITE ANALYSIS ..................................................................................................................................... 24 FLOW CONTROL, LID, AND WATER QUALITY FACILITIES ANALYSIS AND DESIGN .................................... 46 1. EXISTING SITE HYDROLOGY............................................................................................................ 46 2. DEVELOPED SITE HYDROLOGY ....................................................................................................... 48 3. PERFORMANCE STANDARDS ......................................................................................................... 49 4. FLOW CONTROL SYSTEM ............................................................................................................... 49 5. WATER QUALITY SYSTEM ............................................................................................................... 50 6. 100-YEAR FLOOD FIRM MAP/OVERFLOW CONDITION.................................................................. 58 CONVEYANCE SYSTEM ANALYSIS AND DESIGN......................................................................................... 59 SPECIAL REPORTS AND STUDIES ................................................................................................................ 60 OTHER PERMITS ......................................................................................................................................... 60 CSWPP ANALYSIS AND DESIGN .................................................................................................................. 61 ESC PLAN ANALYSIS AND DESIGN (PART A) .......................................................................................... 61 1. EROSION RISK ASSESSMENT .................................................................................................... 61 2. CONSTRUCTION SEQUENCE AND PROCEDURE ....................................................................... 61 3. TRAPPING SEDIMENT .............................................................................................................. 61 4. WET WEATHER TESC ............................................................................................................... 62 SWPPS PLAN DESIGN (PART B) ............................................................................................................. 62 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT .................................... 68 1. CITY OF RENTON BOND QUANTITY WORKSHEET .......................................................................... 68 2. FLOW CONTROL AND WATER QUALITY FACILITY SUMMARY SHEET AND SKETCH ....................... 68 3. DECLARATION OF COVENANT FOR PRIVATELY MAINTAINED FLOW CONTROL AND WATER QUALITY FACILITIES ........................................................................................................................ 68 4. DECLARATION OF COVENANT FOR PRIVATELY MAINTAINED FLOW CONTROL BMPS .................. 68 OPERATION AND MAINTENANCE GUIDELINES ......................................................................................... 69 APPENDIX: A – EXHIBITS: EXISTING AND PROPOSED CONDITIONS B – SPECIAL REPORTS AND STUDIES C – CSWPPP WORKSHEETS D – WWHM2012 INPUT AND OUTPUT NAVIX TopGolf Renton – Renton, WA 1 PROJECT OVERVIEW DESIGN CRITERIA The stormwater management facilities have been designed to meet the 2017 City of Renton Surface Water Design Manual (SWDM) with reference to the 2016 King County Surface Water Design Manual. 2017 MANUAL REQUIREMENTS Duration Analysis: Peak Rate Flow Control Standard (match existing conditions for the 2-, 10-, and 100-year peak storm events) Water Quality Menu: Enhanced WQ Downstream Analysis: ¼ mile Since the project proposes more than 2,000 SF of new plus replaced impervious area, a Full Drainage Review will be required. This project is subject to all nine core requirements and all six special requirements listed in the 2017 City of Renton SWDM. EXISTING CONDITIONS The proposed project is located at 745 Park Avenue North in Renton, Washington (King County) and consists of a single parcel, #20100602900006, totaling approximately 13.68 acres. The site is currently vacant and is comprised of grassy areas throughout with some pavement areas associated with previous site development. There are no trees on-site and there are no known critical areas, other than a small portion at the southeastern corner of the site that is within Zone 2 of the Aquifer Protection Area. This zone prohibits the use of open facilities for stormwater control or otherwise, which are not being proposed as part of the development. See Figure 1 below for the Existing Conditions Map. NAVIX TopGolf Renton – Renton, WA 2 Figure 1: Existing Conditions Map The site is bound by North 8th Street to the north, Logan Avenue North to the west, Park Avenue North to the east, and office buildings with parking structures to the south. It is zoned UC-C, Urban Center Design District C. All adjacent properties surrounding the site are similarly zoned as UC-C. Per the Geotechnical Engineering Report by GeoEngineers, Inc., dated May 18, 2018, on-site soils are comprised of relatively shallow fill overlying alluvial deposits, which consist of very soft to stiff silt with varying sand content and very loose to dense sand with varying silt content. Groundwater was observed as shallow as 4 feet from existing ground surface. The site will not be conducive to stormwater management by infiltration. PRE-DEVELOPMENT STORMWATER RUNOFF The project site is divided into two on-site storm drainage sub-basins and one off-site tributary sub- basin as shown in Figure 2 below. Please see below for a general description of the two on-site basins and the off-site tributary basin. Existing public conveyance system Existing public conveyance system Existing Boeing property stormwater conveyance system Existing Boeing property stormwater conveyance system NAVIX TopGolf Renton – Renton, WA 3 Figure 2: Existing Sub-Basins Map West Basin: Drainage from western portion of project site (West Basin) is conveyed through existing on-site swales and closed conveyance pipes to the basin’s connection point to the existing municipal conveyance system in N 8th Street. From there, the stormwater runoff flows westerly to the intersection of N 8th St and Logan Ave N. The runoff is conveyed southerly to an existing stormwater detention vault located under Logan Ave N, directly west of the project site. The runoff leaves the detention vault and is conveyed northeasterly to the conveyance system convergence point located at the intersection of Logan Ave N and Park Ave N. After this, the runoff enters a drainage ditch and flows to the eastern side of Gene Coulon Memorial Beach Park where it enters a stream. The runoff eventually outfalls to Lake Washington. See downstream analysis section of this report for more details. East Basin: Drainage from the eastern portion of project site (East Basin) is conveyed through existing on-site swales and closed conveyance pipes to the basin’s connection to the existing municipal conveyance system in Park Avenue N. The stormwater runoff is conveyed northwesterly to the conveyance system convergence point located at the intersection of Logan Ave N and Park NAVIX TopGolf Renton – Renton, WA 4 Ave N, where it combines with the runoff from the western portion of the project site. See downstream analysis section of this report for more details. Off-Site Basin: Off-site runoff from the Boeing properties to the south enters the project site from two off-site conveyance systems. The first is an existing 10-inch storm drainage conveyance system that enters the western portion of the project site. As it traverses north across the property to N 8th Street, it transitions to a 24-inch storm drainage pipe. It appears to be conveying surface runoff from the Boeing property to the south. Secondly, there is an existing 24-inch storm drainage pipe that enters the eastern portion of the project site. It traverses the property heading northeast to Park Avenue N. This pipe appears to be conveying runoff from the Boeing office building and the Boeing garage further south (Boeing Basin). Please see Figure 3 below for the existing off-site storm drainage conveyance systems entering the project site. These off-site conveyance systems will be rerouted as described in the Proposed Conditions section below. Figure 3: Existing Off-Site Conveyance Systems NAVIX TopGolf Renton – Renton, WA 5 PROPOSED CONDITIONS The proposed project will consist of a Topgolf recreational facility with multiple hitting bays, a surface parking lot, and associated underground utilities. The project will also include a mixed-use development within the excess acreage to the east, along with associated underground utilities. The project will pursue a Type 3 Master Site Plan approval and Site Plan Review. Main access to the Topgolf portion of the site will be provided by two driveways off Logan Avenue North. Access to the mixed-use development component will be from a driveway off North 8th Street and a driveway off Park Avenue North. The two developments will be connected via an on- site drive aisle along the south side of the site. No additional right-of-way improvements are anticipated. See Figure 4 below for the Developed Conditions Map. Figure 4: Developed Conditions Maps POST-DEVELOPMENT STORMWATER RUNOFF Stormwater will be managed on-site in accordance with the standards of the 2017 City of Renton SWDM. Flows from the two existing western and eastern sub-basins will be maintained as close to the existing conditions as possible. West Basin: For the West Basin, runoff from the proposed building roof and from the proposed western parking lot area will be routed to an underground detention tank facility for flow control. Pollution-generating runoff from the parking lot area will be directed to a Modular NAVIX TopGolf Renton – Renton, WA 6 Wetland Facility to receive enhanced water quality treatment prior to discharge to the proposed underground detention tank facility. The control-released stormwater runoff will then be conveyed to the existing conveyance system within Logan Avenue, which was designed to accept conveyance from the western portion of the project site as confirmed by City of Renton Engineering staff. To match the tributary areas of the western and eastern sub-basins exactly, runoff from the proposed outfield, which straddles the western and eastern sub-basin boundary, would need to split. Splitting the outfield runoff per basin presents additional complexity, such as the need for two stormwater pumps to route the stormwater runoff collected in the targets. An area swap is, therefore, proposed to avoid having to split the outfield runoff. All the stormwater runoff from the outfield area will be routed to the eastern sub-basin to its connection point in Park Avenue N. Runoff from the 24-inch off-site conveyance system that enters the eastern sub- basin from the Boeing property to the center-south will be rerouted to the western sub-basin, instead of to the eastern sub-basin. Please see Figure 5 below for the proposed area swap. Roughly 0.15 acres of additional area is being routed to the western sub-basin; however, the municipal conveyance system has sufficient capacity to handle the flow from this additional 0.15 areas of tributary area as described in the Conveyance Analysis section further in this report. NAVIX TopGolf Renton – Renton, WA 7 Figure 5: Basin Swap East Basin: For the East Basin, in addition to the area swap described above, stormwater runoff from the proposed mixed-use development area and from the proposed eastern parking lot area will be routed to an underground detention vault facility. Pollution-generating runoff from the parking lot area will be directed to a Modular Wetland Facility to receive enhanced water quality treatment prior to discharge to the proposed underground detention vault. Moreover, the mixed-use development area will be responsible for providing a separate enhanced water quality treatment facility to treat runoff from any pollution-generating surfaces before discharging to the underground detention vault. Please see Figure 6 below for the storm drainage sub-basins in the proposed condition. NAVIX TopGolf Renton – Renton, WA 8 Figure 6: Proposed Sub-Basins Map Off-Site Conveyance Systems: As mentioned previously and depicted in Figure 3, there is an existing 10-inch storm drainage pipe and a 24-inch storm drainage pipe that traverses the project site from the Boeing property to the south. Please see Figure 7 below for the proposed reroute of these existing off-site storm drainage conveyance systems. NAVIX TopGolf Renton – Renton, WA 9 Figure 7: Boeing Storm Drainage Re-Route Map See below for the Technical Information Report Worksheet, provided in accordance to the 2017 City of Renton SWDM. NAVIX TopGolf Renton – Renton, WA 10 NAVIX TopGolf Renton – Renton, WA 11 NAVIX TopGolf Renton – Renton, WA 12 NAVIX TopGolf Renton – Renton, WA 13 NAVIX TopGolf Renton – Renton, WA 14 NAVIX TopGolf Renton – Renton, WA 15 NAVIX TopGolf Renton – Renton, WA 16 SITE LOCATION Figure 8: Vicinity Map Location: 745 Park Ave N, Renton, Washington 98057 Section, Township, Range: SEC. 08, TOWNSHIP 23N, RANGE 05E, W.M. Parcel/Tax Lot: 0886610010 Size: 13.68 acres (Full parcel); 13.79 acres (Total on- and off-site area of disturbance) City, County, State: Renton, King County, Washington Governing Agency: City of Renton PROJECT SITE NAVIX TopGolf Renton – Renton, WA 17 DRAINAGE BASIN, SUBBASINS, AND SITE CHARACTERISTICS DRAINAGE BASIN The project site is located within the East Lake Washington – Renton drainage basin. There are no special stormwater management requirements for this drainage basin. SUBBASINS Two site sub-basins are present in the existing conditions. Figure 9: Drainage Basin Map PROJECT SITE NAVIX TopGolf Renton – Renton, WA 18 SOILS Per the Geotechnical Engineering Report by GeoEngineers, Inc., dated May 18, 2018, the on-site soils consist of relatively shallow fill overlying alluvial deposits. The fill was encountered in each of the borings. The fill was observed below the pavement or top soil, and generally consisted of loose to dense sand with varying silt and gravel content. A thin layer of stiff sandy silt with occasional gravel was encountered within the fill at boring B-1. The thickness of fill ranged from 4 feet up to approximately 5 feet. Alluvium was observed below the fill. The alluvium typically consists of very soft to stiff silt with varying sand content and very loose to dense sand with varying silt content. Thin layers of peat were observed within the alluvium layer at various boring locations. The alluvium soil observed at the site includes two sub-layers; upper loose to medium dense alluvium, and lower medium dense to dense alluvium. Groundwater was observed on-site and is located at depths of approximately 4 feet to 12.5 feet below the existing ground surface, which corresponds to approximately Elevations 17.5 feet to 25 feet based on NAVD 88 vertical datum. Based on this, the geotechnical engineer recommends a design groundwater elevation of 25 feet. Per the Geotechnical Engineering Report, the feasibility of infiltration was assessed at the site through review of near surface soil conditions and groundwater levels. Due to a relatively shallow groundwater table, at approximately 4 feet below grade, and the presence of low permeability silt soils near the ground surface, the use of an infiltration facilities is not feasible at this site. NAVIX TopGolf Renton – Renton, WA 19 CONDITIONS AND REQUIREMENTS SUMMARY As required by the 2017 City of Renton Surface Water Design Manual, this project is subject to a Full Drainage Review. Therefore, the storm drainage design for this project is required to comply with, or explain exemptions for, all nine (9) Core Requirements as well as all six (6) Special Requirements. The applicable requirements have been met as follows: CORE REQUIREMENTS Core Requirement #1: Discharge at the Natural Location All surface and storm water runoff from a project must be discharged at the natural location so as not to be diverted onto or away from downstream properties. The manner in which runoff is discharged from the project site must not create a significant adverse impact to downhill properties or drainage systems. Response: Runoff will be collected on site and discharged to one of two existing conveyance system, to which the site currently discharges. No downstream impacts are anticipated. Core Requirement #2: Offsite Analysis All proposed projects must submit an offsite analysis report that assesses potential offsite drainage impacts associated with development of the project site and propose appropriate mitigations of those impacts. The initial permit submittal shall include, at a minimum, a Level 1 downstream analysis as described in Section 1.2.2.1 of the 2016 Manual. Response: A Level 1 Downstream Analysis was completed for this project. See the Offsite Analysis section for details. Core Requirement #3: Flow Control Facilities All proposed projects, including redevelopment projects, must provide onsite flow control facilities to mitigate the impacts of storm and surface water runoff generated by new impervious surface, new pervious surface, and replaced impervious surface targeted for flow mitigation as specified in the following sections. Flow control facilities must be provided and designed to perform as specified by the area-specific flow control facility requirement in Section 1.2.3.1 and in accordance with the applicable flow control facility implementation requirements in Section 1.2.3.2. Response: Stormwater runoff from impervious surfaces will be collected in catch basins and routed to one of two on-site stormwater management systems. In the western portion of the site that includes the new Topgolf building and adjacent parking lot areas, stormwater runoff from the parking lot area will be routed to modular wetland facilities for water quality treatment prior to discharge to underground detention tanks for flow control. The roof runoff from the building will discharge directly to the underground detention tanks. The treated runoff from the western basin will be control-released to the existing municipal conveyance system in Logan Avenue. In the eastern portion of the site that includes the outfield area, the mixed-use development area, and the surface NAVIX TopGolf Renton – Renton, WA 20 parking lot to the southeast, stormwater runoff will be routed to a combination underground detention and wet vault followed by a sand filter vault for water quality treatment and flow control. The treated runoff from the eastern basin will be control-released to the existing municipal conveyance system in Park Avenue. See flow control section of this report for additional information. Core Requirement #4: Conveyance System All engineered conveyance system elements for proposed projects must be analyzed, designed, and constructed to provide a minimum level of protection against overtopping, flooding, erosion, and structural failure as specified in Sections 1.2.4.1, 1.2.4.2, and 1.2.4.3 of the 2016 King County Surface Water Design Manual. Response: Please see the Conveyance System Analysis and Design section of this report. Core Requirement #5: Erosion and Sediment Control All proposed projects that will clear, grade, or otherwise disturb the site must provide erosion and sediment controls to prevent, to the maximum extent practicable, the transport of sediment from the project site to downstream drainage facilities, water resources, and adjacent properties. All proposed projects that will conduct construction activities onsite or offsite must provide stormwater pollution prevention and spill controls to prevent, reduce, or eliminate the discharge of pollutants to onsite or adjacent stormwater systems or watercourses. To prevent sediment transport and pollutant discharges as well as other impacts related to land-disturbing and construction activities, Erosion and Sediment Control (ESC) measures and Stormwater Pollution Prevention and Spill Control (SWPPS) measures that are appropriate to the project site must be applied through a comprehensive Construction Stormwater Pollution Prevention (CSWPP) plan as described in Sections 1.2.5.1 and 1.2.5.3 and shall perform as described in Section 1.2.5.2. In addition, these measures, both temporary and permanent, shall be implemented consistent with the requirements in Section 1.2.5.3 that apply to the proposed project. Response: Construction stormwater pollution prevention measures are an integral part of the project construction documents. These measures will include methods to reduce erosion of on-site site soils and to prevent sediment from inadvertently leaving the project site, such as straw wattles, inlet protection, and marking clearing limits. Erosion and sediment control measures will be designed in conformance with the 2017 City of Renton Surface Water Design Manual standards. A temporary erosion and sediment control plan will be included in a future submittal. Core Requirement #6: Maintenance and Operations Maintenance and operation of all drainage facilities is the responsibility of the applicant or property owner, except those facilities for which King County is granted an easement, tract, or right-of-way and officially assumes maintenance and operation. Drainage facilities must be maintained and operated in compliance with Appendix A, or other maintenance standards as approved by the City. Response: An Operations and Maintenance Manual is provided in this report. NAVIX TopGolf Renton – Renton, WA 21 Core Requirement #7: Financial Guarantees and Liability All drainage facilities constructed or modified for projects (except flow control facilities to be privately maintained) must comply with the financial guarantee requirements and the liability requirements of the City. There are two types of financial guarantees for projects constructing or modifying drainage facilities; the drainage facilities restoration and site stabilization guarantee, and the drainage defect and maintenance guarantee. Response: A Bond Quantity worksheet will be provided in the final version of this report. Core Requirement #8: Water Quality All proposed projects, including redevelopment projects, must provide water quality (WQ) facilities to treat the runoff from new and replaced pollution-generating impervious surfaces and pollution- generating pervious surfaces targeted for treatment. These facilities shall be selected from one of the area-specific WQ menus described in Section 1.2.8.1 and implemented according to the applicable WQ implementation requirements in Section 1.2.8.2. Response: This site is subject to Enhanced Water Quality Treatment, which will be provided by means of a Modular Wetland System in each of the site sub-basins. The Modular Wetland System has Ecology GULD approval to provide enhanced treatment for the offline water quality flow rate as determined by WWHM2012. See the Flow Control, LID, And Water Quality Facilities Analysis and Design section for detailed modeling inputs and calculations. Core Requirement #9: On-Site BMPs All proposed projects, including redevelopment projects, must provide onsite flow control BMPs to mitigate the impacts of storm and surface water runoff generated by new impervious surface, new pervious surface, existing impervious surfaces, and replaced impervious surface targeted for mitigation as specified in the following sections. Flow control BMPs must be selected and applied according to the basic requirements, procedures, and provisions detailed in this section and the design specifications for each BMP in Appendix C, Section C.2. Flow control BMPs are methods and designs for dispersing, infiltrating, or otherwise reducing or preventing development-related increases in runoff at or near the sources of those increases. Flow control BMPs include, but are not limited to, preservation and use of native vegetated surfaces to fully disperse runoff; use of other pervious surfaces to disperse runoff; roof downspout infiltration; permeable pavements; bioretention; limited infiltration systems; and reduction of development footprint. Response: An analysis of the On-Site Stormwater Management BMPs will be provided at a subsequent submittal. NAVIX TopGolf Renton – Renton, WA 22 SPECIAL REQUIREMENTS Special Requirement #1: Other Adopted Area-Specific Requirements The drainage requirements of adopted MDPs, BPs, SCPs, LMPs, HMPs, SDFPs shall be applied in addition to the drainage requirements of the 2016 Manual unless otherwise specified in the adopted regulation. Where conflicts occur between the two, the drainage requirements of the adopted area-specific regulation shall supersede those in the 2016 Manual. Response: There are no known adopted area-specific requirements that apply to the proposed development. Special Requirement #2: Flood Hazard Area Delineation Floodplains and floodways are subject to inundation during extreme events. The 100-year floodplains are delineated in order to minimize flooding impacts to new development and to prevent aggravation of existing flooding problems by new development. Regulations and restrictions concerning development within a 100-year floodplain are found in the Sensitive Areas Ordinance. Response: Per the most current FIRM Map, shown in the 100-year flood/overflow condition section of this report, the project site does not lie within the 100-year floodplain. Special Requirement #3: Flood Protection Facilities Developing sites protected by levees and revetments require a high level of confidence in their structural integrity and performance. Proper analysis, design, and construction are necessary to protect against the potentially catastrophic consequences if such facilities should fail. Response: The project site does not contain levees, revetments, or berm protection. Special Requirement #4: Source Control Water quality source controls prevent rainfall and runoff water from coming into contact with pollutants, thereby reducing the likelihood that pollutants will enter public waterways and violate water quality standards and County stormwater discharge permit limits. The County may require mandatory source controls at any time through formal code enforcement if complaints or studies reveal water quality violations or problems. Response: All applicable non-structural Source Control BMPs will be implemented as outlined in the 2017 City of Renton Surface Water Design Manual. No structural source controls are proposed as of this submittal. Special Requirement #5: Oil Control Projects proposing to develop or redevelop a high-use site must provide oil controls in addition to any other water quality controls. Such sites typically generate high concentrations of oil due to high traffic turnover or the frequent transfer of oil. NAVIX TopGolf Renton – Renton, WA 23 Response: A high-use site is defined in the 2016 KCSWDM as “a commercial or industrial site that has an expected average daily traffic (ADT) count equal to or greater than 100 vehicles per 1,000 square feet of gross building area”. Oil/water separator requirements will be analyzed at a subsequent submittal. Special Requirement #6: Aquifer Protection Area If a proposed project is located within an aquifer protection area, the project is required to determine and delineate applicable components on the project’s site improvement plan. Response: A small portion at the southeastern corner of the site is within Zone 2 of the Aquifer Protection Area. This zone prohibits the use of open facilities for stormwater control or otherwise, which are not being proposed as part of the development. NAVIX TopGolf Renton – Renton, WA 24 OFFSITE ANALYSIS TASK 1: STUDY AREA DEFINITION AND MAPS Available resources such as the survey and topographic maps were utilized to prepare the downstream analysis. The study area extended beyond the required 1/4-mile downstream of the project site. The two conveyance systems impacted by this development have been investigated. Figure 10 shows the general location of the critical areas relative to the proposed project site as designated on the City of Renton Critical Areas Map. No sensitive/critical areas are located on-site. Figure 10: Critical Areas Map PROJECT SITE NAVIX TopGolf Renton – Renton, WA 25 TASK 2: RESOURCE REVIEW The following resources were reviewed for existing/potential problems within the study area: · Site Survey · FEMA F.I.R.M. · City of Renton Critical Areas Map · King County iMap Floodplain · Reported Drainage Complaints · Current DOE 303(d) List A review of drainage complaints from the last 10 years within one-quarter mile of the project site, as supplied by King County, indicates that no drainage complaints have been filed as indicated below in Figure 11. Therefore, no drainage or water quality concerns appear to impact or be impacted by the development of this site. Figure 11: Drainage Complaints Map PROJECT SITE Drainage complaint area, typical NAVIX TopGolf Renton – Renton, WA 26 TASK 3: FIELD INSPECTION UPSTREAM ANALYSIS The project site does not receive additional runoff from upstream properties. The adjacent properties flow away from the project site’s property lines. DOWNSTREAM ANALYSIS A formal downstream analysis has been completed in accordance with the 2017 City of Renton’s Surface Water Design Manual. The downstream analysis was completed on April 19, 2018. The temperature was approximately 60 degrees and was sunny. The project site consists of two drainage sub-basins, which flow to a convergence point, and into one discharge point on Lake Washington. Below is a description of each of the site drainage sub-basins. Figure 12: Downstream Flow Paths NAVIX TopGolf Renton – Renton, WA 27 Conveyance System 1 # Photo Description 1 View from SW corner of site looking east. Drainage from western side of project site is conveyed through pipes and swales on the south side of the site in a westerly direction. 2 View from SW corner of site looking north. Drainage from pipes that follow the southwest side of the site is conveyed into an open- grate catch basin at the SW corner of the site. NAVIX TopGolf Renton – Renton, WA 28 3 View from SW corner of site looking north. Drainage from open- grate catch basin is conveyed through pipes in a northerly direction to N 8th St. Swale drainage is conveyed to a wetland located on the northern end of the site. 4 View from N 8th St looking southwest. Drainage from on-site swales ponding at the northern end of the site. NAVIX TopGolf Renton – Renton, WA 29 5 View from drainage connection point on N 8th St looking west. Drainage from the eastern half of site is conveyed into an open- grate catch basin located in the shoulder of the east-bound travel lane of N 8th St. 6 View from NW corner of the site looking northwest into the intersection of Logan Ave N and N 8th St. Drainage from open- grate catch basin located on the south side of N 8th St is conveyed to a solid- lid manhole in the intersection of Logan Ave N and N 8th St. NAVIX TopGolf Renton – Renton, WA 30 7 View from intersection of Logan Ave N and N 8th St looking south. Drainage from manhole located in the intersection of Logan Ave N and N 8th St is conveyed to an open- grate catch basin located on the east side of Logan Ave N. 8 View from Logan Ave N looking west. Drainage from open- grate catch basin on N Logan Ave is conveyed in a westerly direction through an open-grate catch basin to a pre- existing vault located underneath Logan Ave N, adjacent to the site. NAVIX TopGolf Renton – Renton, WA 31 9 View from Logan Ave N looking north. Drainage from vault is conveyed in a northerly direction along the western side of Logan Ave N. 10 View from Logan Ave N at the intersection of Logan Ave N and N 8th St looking north. Drainage from vault is conveyed in a northerly direction to a solid-lid manhole on the western side of Logan Ave N. NAVIX TopGolf Renton – Renton, WA 32 11 View from Logan Ave N looking north. Drainage from solid-lid manhole is conveyed along Logan Ave N to a solid-lid manhole located at the bus-stop exit at the intersection of Logan Ave N and N 10th St. 12 View from intersection of Logan Ave N and N 10th St looking north. Drainage from solid-lid manhole is conveyed in a northerly direction to a solid-lid manhole located in the intersection of Logan Ave N and N 10th St. Storm Drainage Manhole NAVIX TopGolf Renton – Renton, WA 33 13 View from Logan Ave N looking northeast. Drainage from solid-lid manhole at the intersection of Logan Ave N and N 10th St is conveyed in a northeasterly direction to a solid-lid manhole located in the center of Logan Ave N. 14 View from Logan Ave N looking northeast. Drainage from solid-lid manhole is conveyed in a northeasterly direction to a solid-lid manhole located in the south- bound lane of Logan Ave N. NAVIX TopGolf Renton – Renton, WA 34 15 View from Logan Ave N looking northeast toward the intersection of Logan Ave N and Park Ave N. Drainage from solid-lid manhole is conveyed in a northeasterly direction to a solid-lid manhole located in the south- bound lane of Logan Ave N. 16 View from Logan Ave N looking southeast towards the intersection of Logan Ave N and Park Ave N. Drainage from solid-lid manhole from the south- bound lane of Logan Ave N is conveyed in a northeasterly direction to the conveyance system convergence point, a solid-lid manhole, northeast of the intersection of Logan Ave N and Park Ave N. Conveyance System Convergence Point NAVIX TopGolf Renton – Renton, WA 35 17 View from Lake Washington Blvd N looking northwest. Drainage from conveyance system convergence point conveys to a ditch system along the northwest side of Lake Washington Blvd where it travels under the railway through 84”, 48”, and 48” concrete pipes. Flow was directed into the 48” pipes because of sediment build-up in the 84” pipe. 18 View from Coulon Beach Park Rd looking west. Drainage from Lake Washington Blvd N ditch is conveyed into a stream and flows underneath a bridge located west of the intersection of the railway and Coulon Beach Park Dr. NAVIX TopGolf Renton – Renton, WA 36 19 View from Coulon Beach Park Dr drainage ditch looking north. Drainage conveyed under the bridge located west of the intersection of the railway and Coulon Beach Park Dr goes through another drainage area located on the northern side of the bridge. 20 View from Coulon Beach Park Dr drainage ditch looking south. Drainage from the stream located on the southwest side of Coulon Beach Park Dr underneath Coulon Beach Park Rd is conveyed through two 66” concrete pipes and one 72” pipe. Flow was diverted into the middle 66” pipe because of sediment build up in the outside pipes. 66” Concrete Pipe 66” Concrete Pipe 72” Concrete Pipe NAVIX TopGolf Renton – Renton, WA 37 21 View from Coulon Beach Park Dr drainage ditch looking north. Drainage is conveyed underneath Coulon Beach Park Rd into a stream that runs along the northeast side of Coulon Beach Park. 22 View from northeast side of Coulon Beach Park looking southeast. Drainage is conveyed in a northwesterly direction through a stream along the northeast side of Coulon Beach Park. NAVIX TopGolf Renton – Renton, WA 38 23 View from bridge that connects Coulon Beach Park to an adjacent parking lot looking northwest. Drainage is conveyed through the stream and is discharged into Lake Washington. At the discharge point, the stream is approximately 16 feet wide and 1.5 feet deep. NAVIX TopGolf Renton – Renton, WA 39 Conveyance System 2 # Photo Description 24 View from the south- central location of site looking south. Drainage from western half of project site is conveyed through pipes and swales located on the south side of the site in a northerly direction. NAVIX TopGolf Renton – Renton, WA 40 25 View along existing fence of south-central location of site looking north. Drainage from project site is conveyed to an open-grate catch basin located adjacent to an existing fence. 26 View from center of site looking north. Drainage from open- grate catch basin adjacent to existing fence is conveyed in a northerly direction to an open-grate catch basin located in the center of the site. NAVIX TopGolf Renton – Renton, WA 41 27 View from center of site looking north. Drainage from open- grate catch basin in center of the site is conveyed in a northerly direction to a solid-lid manhole located in the center of the site. 28 View from center of site looking north. Drainage from solid-lid manhole in center of the site is conveyed in a northerly direction to an open-grate catch basin located in the center of the site. NAVIX TopGolf Renton – Renton, WA 42 29 View from north central portion of site looking north. Drainage from open- grate catch basin in center of the site is conveyed in a northerly direction to an elevated manhole located in the north central portion of the site. 30 View from Ross Dress for Less loading bay looking east. Drainage from elevated manhole is conveyed across N 8th St to a solid- lid manhole located in the loading bay area of Ross Dress for Less. NAVIX TopGolf Renton – Renton, WA 43 31 View from intersection of Dick Sporting Good’s parking entrance and Park Ave N looking north. Drainage from loading bay area is conveyed down Park Ave N in a northerly direction. Unable to locate drainage structures from Ross Dress for Less loading bay to the intersection of Park Ave N and N 10th St. 32 View from intersection of Park Ave N and N 10th St looking east. Drainage from system is conveyed in a northerly direction to a solid-lid manhole located in the intersection of Park Ave N and N 10th St. NAVIX TopGolf Renton – Renton, WA 44 33 View from intersection of Park Ave N and N 10th St looking northeast. Drainage from solid-lid manhole is conveyed in an easterly direction to a solid-lid manhole located in the intersection of Park Ave N and N 10th St. 34 View from intersection of Park Ave N and N 10th Pl looking northeast. Drainage from solid-lid manhole is conveyed in a northerly direction to a solid-lid manhole located at the intersection of Park Ave N and N 10th Pl. NAVIX TopGolf Renton – Renton, WA 45 35 View from Logan Ave N looking southeast towards the intersection of Logan Ave N and Park Ave N. Drainage from solid-lid manhole at the intersection of Park Ave N and N 10th Pl is conveyed in a northeasterly direction to the conveyance system convergence point, a solid-lid manhole, northeast of the intersection of Logan Ave N and Park Ave N. Refer to conveyance system 1 for continuation. TASK 4: DRAINAGE SYSTEM DESCRIPTION AND PROBLEM DESCRIPTIONS There are no known problems with the drainage paths around the site. No downstream impacts from the proposed project are anticipated. TASK 5: MITIGATION OF EXISTING OR POTENTIAL PROBLEMS No existing or potential problems were identified as discussed in Task 4 above; therefore, mitigation is not warranted. Conveyance System Convergence Point NAVIX TopGolf Renton – Renton, WA 46 FLOW CONTROL, LID, AND WATER QUALITY FACILITIES ANALYSIS AND DESIGN EXISTING SITE HYDROLOGY The project site is approximately 13.68 acres (596,016 SF) and consists of vacant lot. Runoff from the existing site is conveyed through two conveyance systems. The project site does not receive upstream run-on. The pre-developed conditions are shown in Tables 1a and 1b. See Figures 13 and 14 for the Existing Conditions Map. Table 1a: On-Site Areas (Western Site Sub-Basin) Existing Conditions Area (AC) Description 2.88 Pervious 1.76 Impervious 4.64 Total On-site Area (Western Site Sub-Basin) Table 1b: On-Site Areas (Eastern Site Sub-Basin) Existing Conditions Area (AC) Description 8.48 Pervious 0.56 Impervious 9.04 Total Off-site Area (Eastern Site Sub-Basin) NAVIX TopGolf Renton – Renton, WA 47 Figure 13: Existing Conditions Map (Western Site Sub-Basin) Figure 14: Existing Conditions Map (Eastern Site Sub-Basin) NAVIX TopGolf Renton – Renton, WA 48 DEVELOPED SITE HYDROLOGY The developed surface conditions areas are noted in Tables 2a and 2b. See Figure 15 and 16 for the Developed Conditions Map. Table 2a: On-Site Areas (Western Site Sub-Basin) Developed Conditions Area (AC) Description 0.66 Building (Roof Area) 2.55 Pavement/Sidewalk/Plaza 1.43 Pervious 4.64 Total On-site Area (Western Site Sub-Basin) Table 2b: On-Site Areas (Eastern Site Sub-Basin) Developed Conditions Area (AC) Description 2.38 Phase 2 Impervious 1.32 Pavement/Sidewalk 4.38 Field (Impervious) 0.96 Pervious (Including 10% for Phase 2) 9.04 Total On-site Area (Eastern Site Sub-Basin) Figure 15: Developed Conditions Map (Western Site Sub-Basin) NAVIX TopGolf Renton – Renton, WA 49 Figure 16: Developed Conditions Map (Eastern Site Sub-Basin) PERFORMANCE STANDARDS An analysis of the On-Site Stormwater Management BMPs will be provided at a subsequent submittal. FLOW CONTROL SYSTEM As mentioed previously the project site conveys stormwater to two separate site sub-basins. Below is a discription for how the project will meet flow control requirement for each site sub-basin. The developed western site sub-basin will include a CMP detention tank system, designed per the 2017 City of Renton Surface Water Design Manual. The CMP facility was sized to detain runoff from the entire western site sub-basin area of disturbance (totaling 4.64 acres) prior to discharging to the existing municipal storm system in Logan Ave North. The CMP detention facility was sized using WWHM2012 and the project site was modeled in WWHM with a single point of compliance (POC #1) for the western site sub-basin. The predeveloped conditions were modeled as existing site conditions as required by the 2017 City of Renton Surface Water Design Manual. The developed (mitigated) conditions were modeled as noted in Table 2a with a single basin that routes to an approximate 2-190 LF 60” detention tanks with an approx. total live storage volume of 7,460 CF. The detention tank facility will be fully designed during construction document preparation. The developed eastern site sub-basin will include a detention vault, designed per the 2016 Manual. The detention vault was sized to detain runoff from the entire eastern site sub-basin area of NAVIX TopGolf Renton – Renton, WA 50 disturbance (totaling 9.04 acres) prior to discharging to the existing municipal storm system in Park Ave North. The detention vault was sized using WWHM2012 and the project site was modeled in WWHM with a single point of compliance (POC #1) for the eastern site sub-basin. The predeveloped conditions were modeled as existing site conditions as required by the 2017 City of Renton Surface Water Design Manual. The developed (mitigated) conditions were modeled as noted in Table 2b with a single basin that routes to an approximate 88’ wide x 148’ long x 5’ deep detention vault with an approx. total live storage volume of 65,120 CF. The detention vault facility will be fully designed during construction document preparation. WWHM2012 was utilized to model the pre- and post-development runoff flows in 15-minute timesteps. The areas from Tables 1a, 1b, 2a and 2b above were inputted for the existing and developed conditions, respectively. See the WWHM2012 input and output included in Appendix D. Figure 17: Flow Control Systems WATER QUALITY SYSTEM Per the 2017 City of Renton Surface Water Design Manual, Enhanced Water Quality Treatment is required in this area based on the proposed land use of the project. See Figure 18 below for the locations of the proposed water quality facilities. Detention Tank (Western Site Sub-Basin Flow Control) Detention Vault (Eastern Site Sub-Basin Flow Control) NAVIX TopGolf Renton – Renton, WA 51 Figure 18: Water Quality Systems The proposed development is subject to Enhanced Water Quality Treatment. The water quality design flow for projects that do not require detention is equal to 91% of the developed water quality volume, as determined using WWHM2012 per the 2012 Standards. The stormwater runoff from both site sub-basins will be directed to oil/water separators, if required, followed by a Modular Wetland Systems. The Modular Wetland Systems will be sized using 91% of the 24-hour runoff volume as estimated by WWHM. The water quality flow rate from the western site sub-basin is 0.3411 cfs with a peak 100-year developed flow rate of 2.2744 cfs to the Modular Wetland system. The water quality flow rate from the eastern site sub-basin is 0.216 cfs with a peak 100-year developed flow rate of 3.6439 cfs to the Modular Wetland system. See the WWHM2012 input and output included in Appendix D. Runoff from pollution-generating surfaces will be routed to Modular Wetland Systems for enhanced water quality treatment. Per the Department of Ecology’s GULD approval, the Modular Wetland Systems treat the 15-minute water quality flow rate as calculated by WWHM2012. The Modular Wetland Systems include a pretreatment chamber for pre-settling and an internal high flow bypass weir system to accommodate higher flows without the need for a flow splitter. The Modular Wetland Systems for the proposed redevelopment will be sized by Forterra to accommodate the 15-minute water quality flow rate as calculated by WWHM (0.3411 cfs for the western site sub-basin and 0.216 cfs for the eastern site sub-basin), per Department of Ecology’s GULD approval below: Modular Wetland (Western Site Sub- Basin Enhanced Water Quality Modular Wetland (Eastern Site Sub- Basin Enhanced Water Quality NAVIX TopGolf Renton – Renton, WA 52 NAVIX TopGolf Renton – Renton, WA 53 NAVIX TopGolf Renton – Renton, WA 54 NAVIX TopGolf Renton – Renton, WA 55 NAVIX TopGolf Renton – Renton, WA 56 NAVIX TopGolf Renton – Renton, WA 57 NAVIX TopGolf Renton – Renton, WA 58 100-YEAR FLOOD/OVERFLOW CONDITION Review of the most recent FEMA FIRM as adopted by King County indicates that the development area on the project site does not lie within the 100-year flood plain. The portion of FIRM containing the subject property is included in Figure 19 below. Figure 19: King County FEMA Map PROJECT SITE NAVIX TopGolf Renton – Renton, WA 59 CONVEYANCE SYSTEM ANALYSIS AND DESIGN As demonstrated in the Manning’s Calculations in Figure 20 below, the maximum flow rate for a 12- inch storm drainage pipe at a minimum slope of 0.5% is 2.70 cfs. A full conveyance calculation for each site basin will be provided in the final version of this report. Figure 20: Manning’s Calculation for 12-Inch Pipe NAVIX TopGolf Renton – Renton, WA 60 SPECIAL REPORTS AND STUDIES Special reports and studies for this property include the following (See Appendix C): · DRAFT Geotechnical Report prepared by GeoEngineers, Inc., dated May 18. 2018 OTHER PERMITS Other permits required for this project include the following: · Building Permit and building-related permits · Clearing and Grading Permit NAVIX TopGolf Renton – Renton, WA 61 CSWPPP ANALYSIS AND DESIGN ESC Plan Analysis and Design (Part A) All erosion and sediment control measures shall be governed by the requirements of the King County. A temporary erosion and sedimentation control plan has been prepared to assist the contractor in complying with these requirements. The Erosion and Sediment Control (ESC) plan is included with the construction plans. 1. Erosion Risk Assessment The degree of erosion risk on the proposed project site is minimal. The following factors contribute to a low degree of erosion risk: · Slope across the site is slight. Runoff will not travel at high velocities across the site and, therefore, will not cause noticeable erosion impacts. · The site is already stabilized with hard surfaces and the portions that will be removed will generally create temporary closed depression areas that will trap stormwater runoff. 2. Construction Sequence and Procedure The proposed development will include an erosion/sedimentation control plan designed to prevent sediment-laden run-off from leaving the site during construction. The erosion potential of the site is influenced by four major factors: soil characteristics, vegetative cover, topography and climate. Erosion/sedimentation control is achieved by a combination of structural measures, cover measures, and construction practices that are tailored to fit the specific site. Prior to the start of any grading activity upon the site, all erosion control measures, including stabilized construction entrances, shall be installed in accordance with the construction documents. The best construction practice will be employed to properly clear and grade the site and to schedule construction activities. The planned construction sequence for the construction of the site will be provided with a subsequent submittal. 3. Trapping Sediment Structural control measures will be used to reduce erosion and retain sediment on the construction site. The control measures will be selected to fit specific site and seasonal conditions. The following structural items will be used to control erosion and sedimentation processes: · Compost socks · Catch basin inlet sediment protection · Proper cover measures · Sediment Pond for each Site Sub-Basin (Sizing to be provided in final version of this report) Weekly inspection of the erosion control measures will be required during construction. Any sediment buildup shall be removed and disposed of off-site. Vehicle tracking of mud off-site shall be avoided. Installation of a stabilized construction entrance will be installed at a location to enter the site. The entrances are a minimum requirement and may NAVIX TopGolf Renton – Renton, WA 62 be supplemented if tracking of mud onto public streets becomes excessive. In the event that mud is tracked off site, it shall be swept up and disposed of off-site on a daily basis. Depending on the amount of tracked mud, a vehicle road sweeper may be required. Because vegetative cover is the most important form of erosion control, construction practices must adhere to stringent cover requirements. More specifically, the contractor will not be allowed to leave soils open for more than 14 days and, in some cases, immediate seeding will be required. 4. Wet Weather TESC Operating Plan Work between October 1st and April 30th must adhere to the Wet Season Special Provisions noted in Section D.5.2 in Appendix D of the 2016 KCSWDM. SWPPS Plan Design (Part B) A variety of storm water pollutant controls are recommended for this project. Some controls are intended to function temporarily and will be used as needed for pollutant control during the construction period. These include temporary sediment barriers such as silt fences. For most disturbed areas, permanent stabilization will be accomplished by covering the soil with pavement, building, or vegetation. The CSWPPP Worksheet Forms are located in Appendix C. A. Erosion and Sediment Controls 1. Soil Stabilization - The purpose of soil stabilization is to prevent soil from leaving the site. In the natural condition, soil is stabilized by native vegetation. The primary technique to be used at this project for stabilizing site soil will be to provide a protective cover of grass, pavement, or building. a) See 2016 KCSWDM Section D.3.2.6 for Temporary and Permanent Seeding requirements. b) Structural Controls – See construction plans for the TESC Plan D-2.0. Inlet protection and straw wattles are proposed to minimize siltation of construction activities. c) Clearing Limits – Clearing limits are defined by the placement of silt fence or construction fence. d) Storm Drain Inlet Protection – Curb and grated inlets are protected from the intrusion of silt and sediment through a variety of measures as shown on the Construction Drawings. The primary mechanism is to place controls in the path of flow sufficient to slow sediment-laden water to allow settlement of suspended soils before discharging into the storm sewer. Controls typically provide a secondary benefit by means of filtration. Grated inlets typically include a sturdy frame wrapped in silt fence or crushed stone-lined perimeter to slow the NAVIX TopGolf Renton – Renton, WA 63 flow of water. Curb inlets typically include crushed stone barriers held in place with silt fence material or geotextile fabric. Where inlets are located in paved areas the contractor shall install filter fabric in the catch basin. See 2016 KCSWDM Section D.5.5 for Final Stabilization requirements. B. Other Pollutant Controls Control of sediments has been described previously. Other aspects of this SWPPP are listed below: 1. Dust Control - Construction traffic must enter and exit the site at the stabilized construction entrance. The purpose is to trap dust and mud that would otherwise be carried off-site by construction traffic. Water trucks will be used as needed during construction to reduce dust generated on the site. Dust control must be provided by the General Contractor to a degree that is acceptable to the owner, and in compliance with applicable local and state dust control regulations. After construction, the site will be stabilized (as described elsewhere), which will reduce the potential for dust generation. Chemical treatments have not been approved for this site. The Civil Engineer of Record must be contacted if these are requested to be utilized. 2. Solid Waste Disposal - No solid materials, including building materials, are allowed to be discharged from the site with stormwater. All solid waste, including disposable materials incidental to the major construction activities, must be collected and placed in containers. The containers will be emptied as necessary by a contract trash disposal service and hauled away from the site. The location of solid waste receptacles shall be shown on the TESC Plan D-2.0. Substances that have the potential for polluting surface and/or groundwater must be controlled by whatever means necessary in order to ensure that they do not discharge from the site. As an example, special care must be exercised during equipment fueling and servicing operations. If a spill occurs, it must be contained and disposed so that it will not flow from the site or enter groundwater, even if this requires removal, treatment, and disposal of soil. In this regard, potentially polluting substances should be handled in a manner consistent with the impact they represent. 3. Water Source - Non-storm water components of site discharge must be clean water. Water used for construction which discharges from the site must originate from a public water supply or private well approved by the State Health NAVIX TopGolf Renton – Renton, WA 64 Department. Water used for construction that does not originate from an approved public supply must not discharge from the site. 4. Concrete Waste from Concrete Ready-Mix Trucks – Discharge of excess or waste concrete and/or wash water from concrete trucks will be allowed on the construction site, but only in specifically designated diked areas that have been prepared to prevent contact between the concrete and/or wash water and storm water that will be discharged from the site. Waste concrete can be placed into forms to make riprap or other useful concrete products. The cured residue from the concrete washout diked areas shall be disposed in accordance with applicable state and federal regulations. The jobsite superintendent is responsible for assuring that these procedures are followed. 5. Fuel Tanks – Temporary on-site fuel tanks for construction vehicles shall meet all state and federal regulations. Tanks shall have approved spill containment with the capacity required by the applicable regulations. The tank shall be in sound condition free of rust or other damage which might compromise containment. Hoses, valves, fittings, caps, filler nozzles, and associated hardware shall be maintained in proper working condition at all times. Temporary on-site fuel tanks are not proposed for this project at this time. 6. Hazardous Waste Management and Spill Reporting Plan – Any hazardous or potentially hazardous waste that is brought onto the construction site will be handled properly in order to reduce the potential for storm water pollution. All materials used on this construction site will be properly stored, handled and dispensed following any applicable label directions. Material Safety Data Sheets (MSDS) information will be kept on site for any and all applicable materials. Should an accidental spill occur, immediate action will be undertaken by the General Contractor to contain and remove the spilled material. All hazardous materials will be disposed of by the Contractor in the manner specified by local, state, and federal regulations and by the manufacturer of such products. As soon as possible, the spill will be reported to the appropriate state and local agencies. As required under the provisions of the Clean Water Act, any spill or discharge entering the waters of the United States will be properly reported. The General Contractor will prepare a written record of any such spill and will provide notice to the Owner within 24-hours of the occurrence of the spill. Any spills of petroleum products or hazardous materials in excess of Reportable Quantities as defined by EPA or the state or local agency regulations, shall be immediately reported to the EPA National Response Center (1-800-424-8802) and the Washington State Department of Ecology at (360) 407-6300 or 1-800- 258-5990. The reportable quantity for petroleum products is per the State of Washington is any amount that contacts public waterways or public storm NAVIX TopGolf Renton – Renton, WA 65 systems OR equal to or greater than 1 gallon on a commercial project that does not contact public water systems such as creeks, rivers, lakes, or storm systems and must be reported within 24 hours. The EPA guidelines define spills within the public water systems as those that: violate applicable water quality standards; cause a film or “sheen” upon, or discoloration of the surface of the water or adjoining shorelines; or cause a sludge or emulsion to be deposited beneath the surface of the water or upon adjoining shorelines. The reportable quantity for hazardous materials is per the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), and is any hazardous substance with reportable quantity that appears in Table 302.4of 40 CFR parts 302, for other substance not found on this list, the reportable quantity is one pound. In order to minimize the potential for a spill of hazardous materials to come in contact with stormwater, the following steps will be implemented: a) All materials with hazardous properties (such as pesticides, petroleum products, fertilizers, detergents, construction chemicals, acids, paints, paint solvents, cleaning solvents, additives for soil stabilization, concrete, curing compounds and additives, etc.) will be stored in a secure location, under cover, when not in use. b) The minimum practical quantity of all such materials will be kept on the job site and scheduled for delivery as close to time of use as practical. c) A spill control and containment kit (containing for example, absorbent such as kitty litter or sawdust, acid neutralizing agent, brooms, dust pans, mops, rags, gloves, goggles, plastic and metal trash containers, etc.) will be provided at the storage site. d) All of the product in a container will be used before the container is disposed of. All such containers will be triple rinsed, with water prior to disposal. The rinse water used in these containers will be disposed of in a manner in compliance with state and federal regulations and will not be allowed to mix with storm water discharges. e) All products will be stored in and used from the original container with the original product label. f) All products will be used in strict compliance with instructions on the product label. g) The disposal of excess or used products will be in strict compliance NAVIX TopGolf Renton – Renton, WA 66 with instructions on the product label. 7. Long-Term Pollutant Controls - Storm water pollutant control measures installed during construction, that will also provide benefits after construction, will not be applicable to this project since most of the pollution control measures are already in place. Those sediment barriers that do not interfere with normal operations and appear to provide long-term benefits can be left in place after construction is completed. 8. Source Controls – Per Section 1.3.4 of the 2016 KCSWDM, structural source control measures, such as car was pads or dumpster area roofing, shall be applied to the entire site containing the proposed project, not just the project site. Dumpster area roofing is proposed as a structural source control for this project. B. Construction Phase "Best Management Practices" During the construction phase, the General Contractor shall implement the following measures: 1. Materials resulting from the clearing and grubbing or excavation operations shall be stockpiled up slope from adequate sedimentation controls. Materials removed to an off-site location shall be protected with appropriate controls and properly permitted. 2. The General Contractor shall designate areas on the TESC Plan D-2.0 for equipment cleaning, maintenance, and repair. The General Contractor and subcontractors shall utilize such designated areas. Cleaning, maintenance, and repair areas shall be protected by a temporary perimeter berm, shall not occur within 150 feet away of any waterway, and in areas located as far as practical from storm drains. 3. Use of detergents for large scale washing is prohibited (i.e., vehicles, buildings, pavement surfaces, etc.) 4. Chemicals, paints, solvents, fertilizers, and other toxic materials must be stored in weatherproof containers. Except during application, the contents must be kept in trucks or within storage facilities. Runoff containing such material must be collected, removed from the site, treated, and disposed at an approved solid waste or chemical disposal facility. C. Off-Site Facilities Whenever dirt, rock, or other materials are imported to the construction site or exported for placement in areas off of the primary construction site, the General Contractor is responsible for determining that all stormwater permitting and pollution control requirements are met for each and every site which receives such materials or NAVIX TopGolf Renton – Renton, WA 67 from which such materials are taken. Prior to the disturbance of any such site, the General Contractor will furnish the Owner with a copy of the storm water permit issued for each such site, as well as a copy of the off-site Owners certification statement agreeing to implement necessary storm water pollution prevention measures. The General Contractor will also furnish a copy of the SWPPP for each such site, including a description of the erosion control measures, which will be applied. At a minimum, each off-site area that provides or receives materials or is disturbed by project activities must implement erosion control measures consisting of perimeter controls on all down slope and side slope boundaries and must also provide for both temporary stabilization measures and for permanent re-vegetation after all disturbance is ended. NAVIX TopGolf Renton – Renton, WA 68 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT The following information will be provided in the final version of this report: · Site Improvement Bond Quantity Worksheet · Declaration of Covenant for Maintenance and Inspection of Flow Control BMPs NAVIX TopGolf Renton – Renton, WA 69 OPERATION AND MAINTENANCE GUIDELINES NAVIX TopGolf Renton – Renton, WA 70 NAVIX TopGolf Renton – Renton, WA 71 NAVIX TopGolf Renton – Renton, WA 72 NAVIX TopGolf Renton – Renton, WA 73 NAVIX TopGolf Renton – Renton, WA 74 NAVIX TopGolf Renton – Renton, WA 75 NAVIX TopGolf Renton – Renton, WA 76 APPENDIX A EXHIBITS EXHIBIT A – EXISTING CONDITIONS EXHIBIT B – PROPOSED CONDITIONS APPENDIX B SPECIAL REPORTS AND STUDIES DRAFT Geotechnical Engineering Report prepared by GeoEngineers, Inc., dated May 18, 2018. Geotechnical Engineering Services Draft Report Logan Avenue North and North 8th Street Development Project Renton, Washington for ARCO Murray Design Build May 18, 2018 17425 NE Union Hill Road, Suite 250 Redmond, Washington 98052 425.861.6000 DRAFT Geotechnical Engineering Services Draft Report Logan Avenue North and North 8th Street Development Project Renton, Washington File No. 23325-001-00 May 18, 2018 Prepared for: ARCO Murray Design Build 3110 Woodcreek Drive Downers Grove, Illinois 60515 Attention: Eric Uebelhor Prepared by: GeoEngineers, Inc. 17425 NE Union Hill Road, Suite 250 Redmond, Washington 98052 425.861.6000 Heidi P. Cashman, PE Senior Geotechnical Engineer Lindsay C. Flangas, PE King H. Chin, PE Associate Principal HPC:LCF:tlm Disclaimer: Any electronic form, facsimile or hard copy of the original document (email, text, table, and/or figure), if provided, and any attachments are only a copy of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record. DRAFT May 18, 2018| Page I File No. 23325-001-00 Table of Contents INTRODUCTION ............................................................................................................................................. 1 Project Understanding ........................................................................................................................... 1 FIELD EXPLORATIONS AND LABORATORY TESTING ................................................................................. 1 Field Explorations ................................................................................................................................... 1 Laboratory Testing ................................................................................................................................. 1 SITE CONDITIONS ......................................................................................................................................... 1 Surface Conditions................................................................................................................................. 1 Subsurface Soil Conditions ................................................................................................................... 2 Groundwater Conditions ........................................................................................................................ 2 CONCLUSIONS AND RECOMMENDATIONS ................................................................................................ 2 Earthquake Engineering ........................................................................................................................ 3 Site-Specific Response Spectrum .................................................................................................. 3 Seismic Hazards .............................................................................................................................. 4 Building Foundations ............................................................................................................................. 5 General ............................................................................................................................................ 5 Augercast Piles ................................................................................................................................ 5 Shallow Foundations....................................................................................................................... 8 Ground Improvement ...................................................................................................................... 9 Lowest-Level Building Slab .................................................................................................................. 10 Subgrade Preparation ................................................................................................................... 10 Design Features ............................................................................................................................ 10 Net Poles .............................................................................................................................................. 11 General .......................................................................................................................................... 11 Outfield and Pavement Area Settlement Mitigation .......................................................................... 12 General .......................................................................................................................................... 12 Surcharge and Preload Program .................................................................................................. 13 Below-Grade Walls ............................................................................................................................... 13 Drainage ........................................................................................................................................ 14 Earthwork ............................................................................................................................................. 14 Clearing and Site Preparation ...................................................................................................... 14 Subgrade Preparation ................................................................................................................... 15 Subgrade Protection ..................................................................................................................... 15 Structural Fill ................................................................................................................................. 15 Temporary Cut Slopes ................................................................................................................... 18 Permanent Cut and Fill Slopes ..................................................................................................... 19 Erosion and Sediment Control ..................................................................................................... 19 Utility Trenches .............................................................................................................................. 19 Pavement Recommendations ............................................................................................................. 20 Subgrade Preparation ................................................................................................................... 20 New Hot-Mix Asphalt Pavement ................................................................................................... 20 Portland Cement Concrete Pavement ......................................................................................... 20 DRAFT May 18, 2018 | Page II File No. 23325-001-00 Construction Dewatering ..................................................................................................................... 21 Infiltration Considerations ................................................................................................................... 21 Recommended Additional Geotechnical Services ............................................................................. 21 LIMITATIONS ............................................................................................................................................... 22 REFERENCES .............................................................................................................................................. 22 LIST OF FIGURES Figure 1. Vicinity Map Figure 2. Site Plan Figure 3. Cross Section A-A’ Figure 4. Cross Section B-B’ Figure 5. Recommended Site-Specific MCER Response Spectrum Figure 6. Axial Capacity Plots – 18-inch Augercast Pile (Building) Figure 7. Axial Capacity Plots – 24-inch Augercast Pile (Building) APPENDICES Appendix A. Field Explorations Figure A-1 – Key to Exploration Logs Figures A-2 through A-16 – Log of Explorations Appendix B. Laboratory Testing Figures B-1 through B-3 – Sieve Analysis Results Figures B-4 through B-7– Atterberg Limits Test Results Appendix C. Site-Specific Seismic Response Analysis Figure C-1. As-recorded Response Spectra 2,475-year Event Figure C-2. Spectrally Matched and Filtered Response Spectra Figure C-3. Shear Wave Velocity Profiles – Shallow Figure C-4. Shear Wave Velocity Profiles – Deep Figure C-5. Soil Amplification Factor, Lower Bound Profile 2,475-year Event Figure C-6. Soil Amplification Factors, Upper Bound Profile 2,475-year Event Figure C-7. Soil Amplification Factors, Porfile Comparison 2,475-year Event Figure C-8. Probabilistic MCE Response Spectrum Comparison Figure C-9. Deterministic MCEr Response Spectrum (Seattle Fault, Mw=7.2, Rrup=2.9 km) Figure C-10. Recommended Site-Specific MCER Response Spectrum Appendix D. Report Limitations and Guidelines for Use DRAFT May 18, 2018 | Page 1 File No. 23325-001-00 INTRODUCTION This report presents the results of GeoEngineers’ geotechnical engineering services for the proposed development project located at Logan Avenue North and North 8th Street in Renton, Washington. The site is shown relative to surrounding physical features on Figure 1, Vicinity Map and Figure 2, Site Plan. The purpose of this report is to provide geotechnical engineering conclusions and recommendations for the design of the proposed development. GeoEngineers’ geotechnical engineering services have been completed in general accordance with the scope of services outlined in our Agreement for Professional Services dated March 22, 2018, and Change Order No. 1 dated April 16, 2018. Project Understanding GeoEngineers understands that the proposed development consists of a low-rise structure, an outfield area consisting of turf or lawn and enclosed with nets supported by poles up to 170 feet in height, and surface parking. Our understanding of the project and the required geotechnical scope of services is based on information provided by Eric Uebelhor with Arco Murray Design Build. FIELD EXPLORATIONS AND LABORATORY TESTING Field Explorations The subsurface conditions at the site were evaluated by drilling fifteen borings (B-1, B-2, PB-1, AB-1 through AB-3, OB-1 through OB-7, GEI-1 and GEI-2) and advancing six cone penetration tests (CPTs) (CPT-1 through CPT-6) to depths ranging from approximately 10 to 82 feet below existing site grades. CPTs were advanced to practical refusal. The approximate locations of the explorations are shown in Figure 2. Descriptions of the field exploration program and the boring and CPT logs are presented in Appendix A, Field Explorations. Laboratory Testing Soil samples were obtained during drilling and were taken to GeoEngineers’ laboratory for further evaluation. Selected samples were tested for the determination of moisture content, fines content, grain- size distribution, and plasticity indices (Atterberg limits). A description of the laboratory testing and the test results are presented in Appendix B, Laboratory Testing. SITE CONDITIONS Surface Conditions The site is bounded by office and parking structures to the south, Park Avenue North to the east, North 8th Street to the north, and Logan Avenue North to the west. The site is relatively flat, with up to 2 feet grade difference throughout. The site is currently unoccupied, overall vegetated with grassy areas with some pavement associated with previous site development. Based on our review of historical aerial photographs (available on Google Earth), the site was previously occupied by warehouse structures that were demolished between 2005 and 2007. Underground utilities running below and adjacent to the site consist of storm and sanitary sewer, water, power and communications. DRAFT May 18, 2018 | Page 2 File No. 23325-001-00 Subsurface Soil Conditions GeoEngineers’ understanding of subsurface conditions is based on the results of our exploration program, as described in the ‘Field Explorations’ section of this report. The approximate locations of the explorations are presented in Figure 2. The soils encountered at the site consist of relatively shallow fill overlying alluvial deposits, as shown in Figures 3 and 4, Cross Sections A-A’ and B-B’, respectively, and the boring logs presented in Appendix A. Fill was encountered in each of the borings. Fill was observed below the pavement or top soil, and generally consisted of loose to dense sand with varying silt and gravel content. A thin layer of stiff sandy silt with occasional gravel was encountered within the fill unit in boring B-1. The thickness of fill ranged from 4 feet up to approximately 5 feet. Alluvium was observed below the fill. The alluvium typically consists of very soft to stiff silt with varying sand content and very loose to dense sand with varying silt content. Thin layers of peat were observed within the alluvium unit in borings B-1, AB-2, OB-2, OB-3, OB-5, OB-7 and PB-1. The alluvium soil unit observed at the site includes two sub-units: upper loose to medium dense alluvium, and lower medium dense to dense alluvium, as shown in Figures 3 and 4. Groundwater Conditions Based on conditions observed during drilling, the groundwater table at the site is located at depths of approximately 4 feet to 12.5 feet below the existing ground surface, which corresponds to approximately Elevations 17.5 feet to 25 feet (North American Vertical Datum of 1988 [NAVD 88]). Based on this information and our experience in the site vicinity, we recommend a design groundwater Elevation of 25 feet. Groundwater observations represent conditions observed during exploration and may not represent the groundwater conditions throughout the year. Groundwater seepage is expected to fluctuate as a result of season, precipitation and other factors. CONCLUSIONS AND RECOMMENDATIONS A summary of the geotechnical considerations is provided below. The summary is presented for introductory purposes only and should be used in conjunction with the complete recommendations provided in this report. ■ The results of our liquefaction analyses indicate that fill and loose to medium dense alluvial soils, below the groundwater table, are susceptible to liquefaction during the building code-prescribed maximum- considered earthquake (MCE) event (i.e. earthquake event with 2,500-year return period), which has a rock outcrop peak ground acceleration (PGA) of 0.61g and mean earthquake magnitude of 6.8. Based on our liquefaction analysis, we estimate that free field ground surface settlement on the order of 5 to 13 inches could occur during a MCE-level earthquake due to soil liquefaction. ■ The site is designated as seismic Site Class F per the 2015 International Building Code (IBC) due to the presence of potentially liquefiable soils below the building footprint. As a result, a site-specific seismic response analysis has been completed and is included in Appendix C, Site Specific Seismic Response DRAFT May 18, 2018 | Page 3 File No. 23325-001-00 Analysis. The building should be designed using the recommended MCER site-specific response spectrum presented in Table 1 and Figure 5, Recommended Site-Specific MCER Response Spectrum. As mentioned above, seismic settlements resulting from liquefaction of up to 13 inches are anticipated for the IBC earthquake scenario. ■ Foundation support for the proposed building can be provided by augercast piles or by shallow foundations bearing on improved ground. For shallow foundations bearing on improved ground, an allowable static bearing pressure of 6,000 pounds per square foot (psf) can be used for ground improvement consisting of rigid inclusions with an area replacement ratio of 10 percent. The estimated post-construction static foundation settlement of new footings, prepared as described in this report, is estimated to be less than 1 inch. ■ Design of the at-grade slabs should consider site settlements. In addition to being susceptible to liquefaction, the alluvial soils are compressible and can be anticipated to settle under new loads. Static settlements will depend on the thickness of new fill placed in the building footprint. If slab areas are not supported on deep foundations or improved ground or treated with a preload program, long-term static settlement is anticipated to be greater than 1 inch. The at-grade floor slab for the building should be underlain by at least 6 inches of clean crushed rock for uniform support and as a capillary break. ■ Depending on site grading plans, a preload program is recommended for the outfield area to mitigate static settlements due to new loads. Up to 3 inches of long-term static settlement are estimated for new site fill of up to 5 feet in thickness. Once the planned site grading is available, the preload program can be designed to limit static settlements to tolerable ranges. ■ The feasibility of infiltration was assessed at the site through review of near surface soil conditions and groundwater levels. Due to a relatively shallow groundwater table (4 feet below grade) and the presence of low permeability silt soils near the ground surface, we conclude that the use of large scale infiltration facilities is not feasible at this site. Earthquake Engineering Site-Specific Response Spectrum A site-specific response analysis was completed in accordance with the procedure outlined in Chapter 21 of the American Society of Civil Engineers (ASCE) 7-10 code to develop the site-specific risk-targeted maximum considered earthquake (MCER) response spectrum. The methodology used and the details of the site-specific ground response analyses are presented in Appendix C. The recommended MCER site-specific response spectrum is presented in Figure 5 and is defined in Table 1. The design spectrum is taken as two thirds of the MCER values presented in Table 1 per ASCE 7-10 Section 21.3. TABLE 1. RECOMMENDED SITE-SPECIFIC MCER RESPONSE SPECTRUM Period (sec) Sa (g) 0.01 0.49 0.05 0.70 0.075 0.79 0.10 0.86 0.20 1.04 0.30 1.04 DRAFT May 18, 2018 | Page 4 File No. 23325-001-00 Period (sec) Sa (g) 0.40 1.04 0.50 1.04 0.75 1.04 1.00 1.04 2.00 0.68 3.00 0.40 4.00 0.26 5.00 0.21 Seismic Hazards Surface Fault Rupture The site is located about 2.4 miles south of the Seattle Fault zone. Based on the distance from mapped faults, it is our opinion there is a low risk of fault rupture at the site. Liquefaction Potential Liquefaction refers to a condition in which vibration or shaking of the ground, usually from earthquake forces, results in development of high excess pore water pressures in saturated soils and subsequent loss of stiffness and/or strength in the deposit of soil so affected. In general, soils that are susceptible to liquefaction include loose to medium dense, clean to silty sands and low-plasticity silts that are below the water table. Ground settlement, lateral spreading and/or sand boils may result from soil liquefaction. Structures, such as buildings, supported on or within liquefied soils may experience foundation settlement or lateral movement that can be damaging. We evaluated the liquefaction potential of the site soils based on the information from the borings and CPTs and using the Simplified Procedure (Youd and Idriss, 2001 and Idriss and Boulanger, 2008). The Simplified Procedure is based on comparing the cyclic resistance ratio (CRR) of a soil layer (the cyclic shear stress required to cause liquefaction) to the cyclic stress ratio (CSR) induced by an earthquake. The factor of safety against liquefaction is determined by dividing the CRR by the CSR. Liquefaction hazards, including settlement and related effects, were evaluated when the factor of safety against liquefaction was calculated as less than 1.0. Based on our analyses, the potential exists for liquefaction within the loose to medium dense sandy alluvial deposits encountered in the explorations completed at the site. The cohesive soils (i.e. sandy silt encountered within the alluvium soils) may also experience loss of shear strength during seismic loading. We estimated the factor of safety to be less than 1.0 during a MCE event (i.e. earthquake event with 2,500-year return period), which has a rock outcrop peak ground acceleration (PGA) of 0.61g and mean earthquake magnitude of 6.8 at the project site based on USGS Unified Hazard Tool (Version Dynamic: Conterminous U.S. 2008). Liquefaction-Induced Settlement Estimated ground settlement resulting from earthquake-induced liquefaction was analyzed using empirical procedures based on correlations from the standard penetration test (SPT) results from the soil borings (Tokimatsu and Seed, 1987; Ishihara and Yoshimine, 1992; Idriss and Boulanger, 2008) and the tip DRAFT May 18, 2018 | Page 5 File No. 23325-001-00 penetration resistance results from the CPTs. Liquefaction potential of the site soils was evaluated using the PGA of 0.61g and mean earthquake magnitude of 6.8. Liquefaction-induced ground settlement of the potentially liquefiable soils is estimated to be on the order of 16 inches. Based on the research completed by Cetin et al. (2009), liquefaction at depths greater than 60 feet does not result in settlement that can be observed at the ground surface. In addition, the liquefaction between depths of 40 to 60 feet results in settlement that is approximately one-third of settlement estimated using empirical procedures. Therefore, we estimate the ground surface liquefaction- induced settlement to be on the order of 5 to 13 inches, with the differential settlement between column footings equal to the total estimated settlement. Lateral Spreading Lateral spreading involves lateral displacements of large volumes of liquefied soil. Lateral spreading can occur on near-level ground as blocks of surface soils are displaced relative to adjacent blocks. Lateral spreading also occurs as blocks of surface soils are displaced toward a nearby slope or free-face such as a nearby waterfront or stream bank by movement of the underlying liquefied soil. Due to the distance to a nearby free-face and the relatively flat grade, it is our opinion the risk of lateral spreading is low. Building Foundations General Based on the presence of the compressible peat and organic silt layers and the presence of the potentially liquefiable soils, feasible foundation support for the proposed building can be provided by augercast piles or by shallow foundations bearing on improved ground. Specific design and construction recommendations for each of these options are presented in the following sections of this report. Augercast Piles Augercast piles are constructed using a continuous-flight, hollow-stem auger attached to a set of leads supported by a crane or installed with a fixed-mast drill rig. The first step in the pile casting process consists of drilling the auger into the ground to the specified tip elevation of the pile. Grout is then pumped through the hollow-stem during steady withdrawal of the auger, replacing the soils on the flights of the auger. The final step is to install a steel reinforcing cage and typically a center bar into the column of fresh grout. One benefit of using augercast piles is that the auger provides support for the soils during the pile installation process, thus eliminating the need for temporary casing or drilling fluid. Construction Considerations The augercast piles should be installed using a continuous-flight, hollow-stem auger. As is standard practice, the pile grout must be pumped under pressure through the hollow stem as the auger is withdrawn. Maintenance of adequate grout pressure at the auger tip is critical to reduce the potential for encroachment of adjacent native soils into the grout column. The rate of withdrawal of the auger must remain constant throughout the installation of the piles to reduce the potential for necking of the piles. Failure to maintain a constant rate of withdrawal of the auger should result in immediate rejection of that pile. Reinforcing steel for bending and uplift should be placed in the fresh grout column as soon as possible after withdrawal of the auger. Centering devices should be used to provide concrete cover around the reinforcing steel. DRAFT May 18, 2018 | Page 6 File No. 23325-001-00 The contractor should adhere to a waiting period of at least 12 hours between the installation of piles spaced closer than 8 feet, center-to-center. This waiting period is necessary to avoid disturbing the curing concrete in previously cast piles. Grout pumps must be fitted with a volume-measuring device and pressure gauge so that the volume of grout placed in each pile and the pressure head maintained during pumping can be observed. A minimum grout line pressure of 100 pounds per square inch (psi) should be maintained. The rate of auger withdrawal should be controlled during grouting such that the volume of grout pumped is equal to at least 115 percent of the theoretical pile volume. A minimum head of 10 feet of grout should be maintained above the auger tip during withdrawal of the auger to maintain a full column of grout and to prevent hole collapse. The geotechnical engineer of record should observe the drilling operations, monitor grout injection procedures, record the volume of grout placed in each pile relative to the calculated volume of the hole and evaluate the adequacy of individual pile installations. Axial Capacity Axial pile load capacity in compression is developed from end bearing and from side frictional resistance in the medium dense to dense alluvial soils. Uplift pile capacity will also be developed from side frictional resistance in these soils. Axial pile capacities for 18- and 24-inch-diameter augercast piles are presented in Figures 6 and 7. Allowable pile capacities were evaluated based on Allowable Stress Design (ASD) and are for combined dead plus long-term live loads and may be increased by one-third when considering design loads of short duration such as seismic forces. The allowable capacities are based on the strength of the supporting soils and include a factor of safety of 2 for end bearing and side friction. Allowable pile capacities include the effects of downdrag. The capacities apply to single piles. If piles are spaced at least three pile diameters on center, as recommended, no reduction of axial capacity for group action is needed, in our opinion. The structural characteristics of pile materials and structural connections may impose limitations on pile capacities and should be evaluated by the structural engineer. For example, steel reinforcing will be needed for augercast piles subjected to uplift or large bending moments. Lateral Capacity Lateral loads can be resisted by passive soil pressure on the vertical piles and by the passive soil pressures on the pile cap. Because of the potential separation between the pile-supported foundation components and the underlying soil from settlement, base friction along the bottom of the pile cap should not be included in calculations for lateral capacity. Table 2 summarizes recommended design parameters for laterally loaded piles. We recommend that these parameters be incorporated into the commercial software LPILE to evaluate response and capacity of piles subject to laterally loading. For potentially liquefiable soils, a p-multiplier of 0.1 should be applied to the model P-Y curve of the relevant soil units for evaluating seismic conditions. DRAFT May 18, 2018 | Page 7 File No. 23325-001-00 TABLE 2. LPILE SOIL PARAMETERS Soil Unit1 Approximate Depth Below Ground Surface (feet) Effective Unit Weight (pcf) Friction Angle (degrees) Stiffness Parameter, k (pci) P-Multiplier Top of Soil Layer Bottom of Soil Layer Fill 0 4 120 34 110 - Loose to Medium Dense Alluvium 4 60 57.6 32 50 1 (static) 0.1 (seismic) Medium Dense to Dense Alluvium 60 200 57.6 38 120 - Notes: 1 Sand (Reese) Model pcf – pounds per cubic foot psf – pounds per square foot pci – pounds per cubic inch Piles spaced closer than five pile diameters apart will experience group effects that will result in a lower lateral resistance for trailing rows of piles with respect to leading rows of piles for an equivalent deflection. We recommend that the lateral load capacity for piles in a pile group spaced less than five pile diameters apart be reduced in accordance with the factors in Table 3 per American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications Section 10.7.2.4. TABLE 3. PILE P-MULTIPLIERS, PM, FOR MULTIPLE ROWS Pile Spacing1 (In Terms of Pile Diameter) P-Multipliers, Pm2, 3 Row 1 Row 2 Row 3 and Higher 3D 0.80 0.40 0.30 5D 1.00 0.85 0.70 Notes: 1 The P-multipliers presented are a function of the center-to-center spacing of piles in the group in the direction of loading expressed in multiples of the pile diameter, D. 2 The values of Pm were developed for vertical piles only. 3 The P-multipliers are dependent on the pile spacing and the row number in the direction of the loading. To establish values of Pm for other pile spacing values, interpolation between values should be conducted. We recommend that the passive soil pressure acting on the pile cap be estimated using an equivalent fluid density of 350 pounds per cubic foot (pcf) where the soil adjacent to the foundation consists of adequately compacted structural fill. This passive resistance value includes a factor of safety of 1.5 and assumes a minimum lateral deflection of 1 inch to fully develop the passive resistance. Deflections that are less than 1 inch will not fully mobilize the passive resistance in the soil. Pile Settlement We estimate that the post-construction settlement of pile foundations, designed and installed as recommended, will be on the order of 1 inch or less. Maximum differential settlement should be less than DRAFT May 18, 2018 | Page 8 File No. 23325-001-00 about one-half the post-construction settlement. Most of this settlement will occur rapidly as loads are applied. Shallow Foundations Allowable Bearing Pressure The building can be supported on shallow foundations provided the foundations bear on improved ground. Rigid inclusion ground improvement was considered for this evaluation and is discussed in further detail in the “Ground Improvement” section. For preliminary purposes, footings may be designed using a maximum net allowable soil bearing value of 6,000 psf on properly-compacted structural fill consisting of at least a 2-foot-thick layer of crushed rock above ground improved with rigid inclusions with an area-replacement ratio of 10 percent. The net allowable soil bearing values apply to the total of dead and long-term live loads and may be increased by up to one-third for wind or seismic loads. Size and Embedment The design frost depth for the Puget Sound area is 12 inches; therefore, we recommend that exterior footings for the structures be founded at least 18 inches below lowest adjacent finished grade. Interior footings should be founded at least 12 inches below bottom of slab or adjacent finished grade. For shallow foundation support, we recommend widths of at least 18 and 36 inches, respectively, for continuous wall and isolated column footings supporting the proposed building. Settlement Provided all loose soil is removed and the subgrade is prepared as recommended under “Construction Considerations” below, total settlement of shallow foundations is anticipated to be less than 1 inch. The settlement will occur rapidly, essentially as loads are applied. Differential settlements measured along 25 feet of wall foundations or between similarly loaded column footings are expected to be less than 1 inch. Lateral Resistance Lateral foundation loads may be resisted by passive resistance on the sides of footings and by friction along the base of the footings. For footings supported on structural fill placed and compacted in accordance with our recommendations, the allowable frictional resistance may be computed using a coefficient of friction of 0.35 applied to vertical dead-load forces. The allowable passive resistance may be computed using an equivalent fluid density of 350 pounds per cubic foot (pcf) (triangular distribution). This value is appropriate for foundation elements that are surrounded by structural fill. The structural fill should extend out from the face of the foundation element for a distance at least equal to three times the height of the element and be compacted to at least 95 percent of the maximum dry density (MDD). The above coefficient of friction and passive equivalent fluid density values incorporate a factor of safety of about 1.5. Footing Drains We recommend that perimeter footing drains be installed around the building where the lowest finished floor is lower than adjacent site grades. The perimeter drains should be installed at the base of the exterior footings. The perimeter drains should be provided with cleanouts and should consist of at least 4-inch- diameter perforated pipe placed on a 3-inch bed of, and surrounded by, 6 inches of drainage material enclosed in a non-woven geotextile fabric such as Mirafi 140N (or approved equivalent) to prevent fine soil DRAFT May 18, 2018 | Page 9 File No. 23325-001-00 from migrating into the drain material. We recommend that the drainpipe consist of either heavy-wall solid pipe (SDR-35 polyvinyl chloride [PVC], or equal) or rigid corrugated smooth interior polyethylene pipe (ADS N-12, or equal). We recommend against using flexible tubing for footing drainpipes. The drainage material should consist of Gravel Backfill for Drains conforming to Section 9-03.12(4) of the 2018 Washington State Department of Transportation (WSDOT) Standard Specifications. The perimeter drains should be sloped to drain by gravity to a suitable discharge point, preferably a storm drain. We recommend that the cleanouts be covered and be placed in flush mounted utility boxes. Water collected in roof downspout lines must not be routed to the footing drain lines. Construction Considerations Immediately prior to placing concrete, all debris and soil slough that accumulated in the footings during forming and steel placement must be removed. Debris or loose soils not removed from the footing excavations will result in increased settlement. We recommend that the footing excavations be cut using a smooth-edged bucket to reduce the amount of disturbed soil exposed at the subgrade. If wet weather construction is planned, we recommend that all footing subgrades be protected using a lean concrete mud mat. The mud mat should be placed the same day that the footing subgrade is excavated and approved for foundation support. The condition of all footing excavations should be observed by the Geotechnical Engineer to evaluate if the work is completed in accordance with our recommendations and that the subsurface conditions are as anticipated. Ground Improvement Ground improvement is recommended to mitigate potentially liquefiable soils and to control foundation settlement. Based on our experience, rigid inclusions are a feasible and economical ground improvement option for this site. GeoEngineers can design the ground improvement system in collaboration with the general contractor and structural engineer. General recommendations are provided below for ground improvement using rigid inclusions. During the design phase of the project, foundation support options should be reviewed with the project team to determine the preferred foundation support alternative. The purpose of ground improvement is to mitigate potential static and/or seismic induced settlement resulting from consolidation and seismic liquefaction of the alluvial deposits. The benefits of ground improvement for this site include: ■Ground improvement will allow for conventional shallow foundations and slabs on grade, both of which are anticipated to result in more efficient and more cost-effective construction; and ■Ground improvement will mitigate the potential settlement resulting from liquefaction of the native alluvial soils during the design seismic event to tolerable magnitudes. Rigid Inclusions Rigid inclusions consist of unreinforced lean concrete columns installed below the building foundation elements on a variable grid pattern. The purpose of the rigid inclusions placed in a grid pattern is to provide a significantly higher strength material capable of dissipating building loads in a less concentrated manner and to provide a ‘block’ of a composite soil and lean concrete material that will reduce the potential for differential settlement. DRAFT May 18, 2018 | Page 10 File No. 23325-001-00 Advantages with the use of rigid inclusions include: ■They are more economical than augercast piles (shorter length, no reinforcement and allows for the use of conventional spread footings/slabs on grade); ■There is minimal disturbance of adjacent structures during installation; and ■There is a lower level of construction noise (i.e. no pile driving), there will be lesser impacts to nearby businesses/residences/buried utilities during construction. Rigid inclusions for this site would be constructed using similar techniques for installing augercast piles. Where augercast methods are used, the first step in the rigid inclusion casting process consists of drilling the auger into the ground to the specified tip elevation of the column. Grout is then pumped into the hole through the base of the auger. The layout/design of the rigid inclusions will be completed once the building design has been finalized. For preliminary design and pricing purposes, rigid inclusions may consist of the following: ■18- to 24-inch-diameter columns; ■An area of replacement of 10 percent; ■Rigid inclusions should extend at least 60 feet deep beginning about 2 feet below the bottom of foundations and floor slabs; and, ■At least 2 feet of clean crushed rock with negligible sand and fines should be placed over the top of the rigid inclusions under the floor slab and foundations. This layer of crushed rock will help transfer loads from the foundations and slab-on-grade to the rigid inclusions and will help reduce differential settlement. GeoEngineers can assist the project team with preparation of the ground improvement plan and specifications once the foundation layout and building loads have been finalized. Lowest-Level Building Slab Subgrade Preparation Floor slab support will be dependent of the type of foundation support selected for the building, the potential for long-term static settlement due to the building pad fill, and the tolerance for liquefaction- induced settlement. If mitigation of static and/or liquefaction-induced settlement is required, the slab can be supported structurally (augercast piles) or constructed as a slab-on-grade with ground improvement below the slab (rigid inclusions). If settlement mitigation is not required, the slab can be constructed as a slab-on-grade without ground improvement. We recommend that slab-on-grade floors be structurally connected to deep foundations (augercast piles) or supported on improved ground (stone columns or rigid inclusions). Design Features We recommend that the floor slabs be underlain by a capillary break gravel layer consisting of at least 6 inches of clean crushed gravel meeting the requirements of Mineral Aggregate Type 22 (¾-inch crushed gravel), City of Seattle Standard Specification 9-03.16. The gravel layer should be placed directly over compacted structural fill. If a 2-foot-thick layer of crushed rock is placed as part of ground improvement DRAFT May 18, 2018 | Page 11 File No. 23325-001-00 plans, it will also suffice as a capillary break layer. For slabs designed as a beam on an elastic foundation, a modulus of subgrade reaction of 85 pounds per cubic inch (pci) may be used for subgrade soils prepared as recommended above. If water vapor migration through the slabs is objectionable, the gravel should be covered with a heavy plastic sheet, such as 10-mil plastic sheeting, to act as a vapor retarder. This will be necessary in occupied spaces and where the slabs will be surfaced with tile or will be carpeted. It may also be prudent to apply a sealer to the slab to further retard the migration of moisture through the floor. The contractor should be made responsible for maintaining the integrity of the vapor retarder during construction. Net Poles General Based on information provided by ARCO Murray, it is our understanding that typical net pole foundations consist of 3-, 4- and 5-foot-diameter drilled concrete piles. The net pole foundations are to be designed by others. The contact between the loose to medium dense (upper) and the medium dense to dense (lower) alluvial soils vary across the site, as shown on the cross-sections developed for this project, Figures 3 and 4. Based on our explorations completed at the site, we have identified three contact depths between the upper and lower alluvial soils, within the west, southeast and northeast net pole zones. The following sections present our design recommendations for each of the net pole area zones and foundation sizes being considered for this project. Axial Capacity We understand that the net pole design is controlled by lateral capacity. Axial pile load capacity in compression is developed from end bearing and from side frictional resistance in the underlying soils, and uplift pile capacity will also be developed from side frictional resistance. Table 4 presents allowable axial capacities for 3-, 4- and 5-foot-diameter drilled concrete piles embedded at least 5 feet into the lower medium dense to dense alluvium. Allowable pile capacities were evaluated based on Allowable Stress Design (ASD) and are for combined dead plus long-term live loads. The allowable capacities are based on the strength of the supporting soils and include a factor of safety of 2 for end bearing and side friction. During ground shaking, the net pole foundations will experience reduction in downward capacity and will be subjected to downdrag as a result of liquefaction. TABLE 4. ALLOWABLE STATIC AXIAL CAPACITY FOR NET POLE FOUNDATIONS Foundation Diameter Allowable Axial Capacity (5-foot minimum embedment into medium dense to dense alluvium) Downward (Static Conditions) Downward (Seismic Conditions) Uplift (Seismic Conditions) 3-foot 250 kips 110 kips 60 kips 4-foot 400 kips 250 kips 75 kips 5-foot 500 kips 300 kips 90 kips The capacities apply to single piles. If piles are spaced at least three pile diameters on center, as recommended, no reduction of axial capacity for group action is needed, in our opinion. DRAFT May 18, 2018 | Page 12 File No. 23325-001-00 Lateral Capacity Lateral loads can be resisted by passive soil pressure on the vertical piles for the net pole foundations. Table 5 summarizes recommended design parameters for laterally loaded piles, within the west, southeast and northeast net pole zones, respectively. We recommend that these parameters be incorporated into the commercial software LPILE to evaluate response and capacity of piles subject to laterally loading. For potentially liquefiable soils, a p-multiplier of 0.1 should be applied to the model P-Y curve of the relevant soil units. TABLE 5. LPILE SOIL PARAMETERS FOR NET POLE FOUNDATIONS Soil Unit1 Approximate Depth Below Ground Surface (feet) Effective Unit Weight (pcf) Friction Angle (degrees) Stiffness Parameter, k (pci) P- Multiplier Top of Soil Layer Bottom of Soil Layer Fill 0 4 120 34 110 - Loose to Medium Dense Alluvium 4 55 to 802 57.6 32 50 1 (static) 0.1 (seismic) Medium Dense to Dense Alluvium 55 to 802 200 57.6 38 120 - Notes: 1 Sand (Reese) Model 2 Refer to Figures 3 and 4 pcf – pounds per cubic foot psf – pounds per square foot pci – pounds per cubic inch Piles spaced closer than five pile diameters apart will experience group effects that will result in a lower lateral resistance for trailing rows of piles with respect to leading rows of piles for an equivalent deflection. We recommend that the lateral load capacity for piles in a pile group spaced less than five pile diameters apart be reduced in accordance with the factors in Table 3 (above) per AASHTO LRFD Bridge Design Specifications Section 10.7.2.4. We recommend that the net pole foundations be designed using a static allowable lateral bearing pressure of 1,000 psf where the soil adjacent to the foundation consists of undisturbed native soil. For seismic design conditions, the lateral capacity should be evaluated using the parameters presented in Table 5 above, with the appropriate P-multiplier. Outfield and Pavement Area Settlement Mitigation General The outfield and pavement areas are underlain by compressible alluvial soils that will experience long-term static settlement if subjected to new loads from site fill. The site grading plans have not yet been determined, but based on preliminary analysis, we estimate up to 3 inches of long-term static settlement resulting from up to 5 feet of new site fill. Depending on new fill thickness, a surcharge and preload program is recommended to mitigate static settlements due to new loads where long term static settlement is not desirable. Once the grading plan is determined, the surcharge and preload program should be designed to DRAFT May 18, 2018 | Page 13 File No. 23325-001-00 limit post-construction static settlement to tolerable ranges. Preliminary design recommendations are presented below. Surcharge and Preload Program The purpose of the surcharge and preload fill is to induce, prior to final site grading and project completion, a significant portion of the settlement that will occur when new loads are applied. The program will significantly reduce post-construction settlement and potential differential settlements due to variability in areal loading and thickness of compressible soils. For preliminary design and pricing purposes, the following outlines a summary of our preliminary recommendations for grading and constructing the preload area: ■ The surcharge/preload fill area should extend approximately 5 feet beyond the extent of the area where settlement is being mitigated. ■ The proposed surcharge/preload fill should be at least 1-foot-thick, in addition to planned fill. The surcharge/preload fill toe should be sloped at a 1H:1V (horizontal to vertical) slope. The top of the mound should be crowned and sloped for drainage. Our preliminary estimate for the height of the surcharge/preload fill was developed assuming that the preload fill has a total moist density of at least 120 pounds pcf. If the material used for the preload weighs less than 120 pcf, the height of the preload fill mound should be adjusted. ■ The surcharge/preload fill should be placed in lifts (not to exceed 12 inches in thickness) and compacted to 95 percent MDD to planned final grade elevation per the project civil engineer. A minimum compaction level of 85 percent should be achieved for the surcharge fill above planned final grade elevation. ■ Settlement plates should be installed within the preload fill area. Settlement plate weekly survey readings should be obtained during construction of preload fill. The first round of survey readings should be obtained before the first lift of preload fill is placed. After the preload fill has been fully constructed the settlement plates should also be surveyed on a weekly basis. The settlement monitoring data will be used to confirm that the preload program is adequately completed. ■ Depending on planned new fill thickness, we estimate that the surcharge/preload fill will be required to remain in place for a duration of 9 to 12 weeks. Below-Grade Walls Conventional cast-in-place walls may be necessary for small retaining structures (i.e. retaining or dock-high walls) located on-site. The lateral soil pressures acting on conventional cast-in-place subsurface walls will depend on the nature, density and configuration of the soil behind the wall and the amount of lateral wall movement that can occur as backfill is placed. For walls that are free to yield at the top at least 0.1 percent of the height of the wall, soil pressures will be less than if movement is limited by such factors as wall stiffness or bracing. Assuming that the walls are backfilled, and drainage is provided as outlined in the following paragraphs, we recommend that yielding walls supporting horizontal backfill be designed using an equivalent fluid density of 35 pcf (triangular distribution), and that non-yielding walls supporting horizontal backfill be designed using an equivalent fluid density of 55 pcf (triangular distribution). For seismic loading conditions, a rectangular earth pressure DRAFT May 18, 2018 | Page 14 File No. 23325-001-00 equal to 8H psf, where H is the height of the wall, should be added to the active/at-rest pressures. For lateral earth pressure due to surcharge loads, a rectangular earth pressure equals to 0.2q, where q is the uniform surcharge pressure on top of wall, should be added to the active/at-rest pressures. Lateral resistance for conventional cast-in-place walls can be provided by frictional resistance along the base of the wall and passive resistance in front of the wall in accordance with the “Lateral Resistance” discussion earlier in this report. The above soil pressures assume that wall drains will be installed to prevent the buildup of hydrostatic pressure behind the walls, as discussed in the paragraphs below. If the walls are installed under the design groundwater table, hydrostatic pressure behind the walls should be estimated by 62.4Hw psf (triangular distribution), where Hw is the height of groundwater table estimated from the bottom of the wall. Drainage Positive drainage should be provided behind cast-in-place retaining walls by placing a minimum 2-foot-wide zone of Gravel Backfill for Walls conforming to Section 9-03.12(2) of the 2018 WSDOT Standard Specifications. A perforated or slotted drainpipe should be placed near the base of the retaining wall to provide drainage. The drainpipe should be surrounded by a minimum of 6 inches Gravel Backfill for Drains conforming to Section 9-03.12(4) of the 2018 WSDOT Standard Specifications. The Gravel Backfill for Drains should be wrapped with a geotextile filter fabric meeting the requirements of construction geotextile for underground drainage, WSDOT Standard Specification 9-33. The wall drainpipe should be connected to a header pipe and routed to a sump or gravity drain. Appropriate cleanouts for drainpipe maintenance should be installed. A larger-diameter pipe will allow for easier maintenance of drainage systems. Earthwork Clearing and Site Preparation All areas to receive fill, structures or pavements should be cleared of vegetation and stripped of topsoil. Clearing should consist of removal of all trees, brush and other vegetation within the designated clearing limits. The topsoil materials could be separated and stockpiled for use in areas to be landscaped. Debris associated with building and site work demolition should be removed from the site, but organic materials could be chipped/composted and reused in landscape areas, if desired. We anticipate that the depth of stripping to remove topsoil will generally be about 6 to 12 inches, where present. Stripping depths may be greater in some areas, particularly where trees and large vegetation have been removed. Actual stripping depths should be determined based on field observations at the time of construction. The organic soils can be stockpiled and used later for landscaping purposes or may be spread over disturbed areas following completion of grading. If spread out, the organic strippings should be in a layer less than 1-foot-thick, should not be placed on slopes greater than 3H:1V and should be track-rolled to a uniformly compacted condition. Materials that cannot be used for landscaping or protection of disturbed areas should be removed from the project site. Care must be taken to minimize softening of the subgrade soils during stripping operations. Areas of the exposed subgrade which become disturbed should be compacted to a firm, non-yielding condition, if practical, prior to placing any structural fill necessary to achieve design grades. If this is not practical DRAFT May 18, 2018 | Page 15 File No. 23325-001-00 because the material is too wet, the disturbed material must be aerated and recompacted or excavated and replaced with structural fill. Subgrade Preparation Prior to placing new fills, pavement or hardscape base course materials, and gravel below on-grade floor slabs, subgrade areas should be proof-rolled to locate soft or pumping soils. Prior to proof rolling, unsuitable soils should be removed from below building and pavement/hardscape areas. Proof-rolling can be completed using a piece of heavy tire-mounted equipment such as a loaded dump truck. During wet weather, the exposed subgrade areas should be probed to determine the extent of soft soils. If soft or pumping soils are observed, they should be removed and replaced with structural fill. If deep pockets of soft or pumping soils are encountered outside the building footprint, it may be possible to limit the depth of overexcavation by placing a woven geotextile fabric such as Mirafi 500X (or similar material) on the overexcavated subgrade prior to placing structural fill. The geotextile will provide additional support by bridging over the soft material and will help reduce fines contamination into the structural fill. This may be performed under pavement areas depending on actual conditions observed during construction, but it should not occur under the planned building. After completing the proof-rolling, the subgrade areas should be recompacted to a firm and unyielding condition, if possible. The achievable degree of compaction will depend on when construction is performed. If the work is performed during dry weather conditions, we recommend that all subgrade areas be recompacted to at least 95 percent of the MDD in accordance with the American Society for Testing and Materials (ASTM) D 1557 test procedure (modified Proctor). If the work is performed during wet weather conditions, it may not be possible to recompact the subgrade to 95 percent of the MDD. In this case, we recommend that the subgrade be compacted to the extent possible without causing undue heaving or pumping of the subgrade soils. Subgrade disturbance or deterioration could occur if the subgrade is wet and cannot be dried. If the subgrade deteriorates during proof rolling or compaction, it may become necessary to modify the proof rolling or compaction criteria or methods. Subgrade Protection Site soils may contain significant fines content (silt/clay) and will be highly sensitive and susceptible to moisture and equipment loads. The contractor should take necessary measures to prevent site subgrade soils from becoming disturbed or unstable. Construction traffic during the wet season should be restricted to specific areas of the site, preferably areas that are surfaced with crushed rock materials not susceptible to wet weather disturbance. Structural Fill All fill, whether on-site soils or imported fill for support of foundations, floor slab areas, pavement areas and as backfill for retaining walls or in utility trenches should meet the criteria for structural fill presented below. Structural fill soils should be free of organic matter, debris, man-made contaminants and other deleterious materials, with no individual particles larger than 4 inches in greatest dimension. The suitability of soil for use as structural fill depends on its gradation and moisture content. DRAFT May 18, 2018 | Page 16 File No. 23325-001-00 Fill Criteria Recommended structural fill material quality varies depending upon its use as described below: ■ Structural fill to construct pavement areas, to place below foundations and slabs, to construct embankments, to backfill retaining walls and utility trenches, and to place against foundations should consist of gravel borrow as described in Section 9-03.14(1) of the 2018 WSDOT Standard Specifications, with the additional restriction that the fines content be limited to no more than 5 percent, especially if the work occurs in wet weather or during the wet season (October through May). However, if earthwork occurs during the normally dry months (June through September) on-site sandy soils that are properly moisture conditioned, that are free of concrete rubble and other debris, and that can be properly compacted may be used as structural fill in these areas. It may be possible to use on-site sandy soils during wet weather for areas requiring only 90 percent compaction provided the earthwork contractor implements good wet weather techniques and drier soils are used; however, we recommend gravel borrow be specified for planning/bidding purposes. ■ Structural fill placed in the minimum 2-foot-wide drainage zone behind retaining walls consist of Gravel Backfill for Walls conforming to Section 9-03.12(2) of the 2018 WSDOT Standard Specifications. ■ Structural fill placed around wall and footing drains should consist of Gravel Backfill for Drains conforming to Section 9-03.12(4) of the 2018 WSDOT Standard Specifications. ■ Structural fill placed as capillary break material below slab-on-grade floors should consist of clean crushed rock and meet the gradation requirements of Mineral Aggregate Type 22 (¾-inch crushed gravel), City of Seattle Standard Specification 9-03.16. The capillary break may be eliminated if ground improvement methods are used to support the buildings and a 2-foot thick crushed rock layer is placed below the slabs. ■ Structural fill placed as crushed surfacing base course below pavements should conform to Section 9-03.9(3) of the 2018 WSDOT Standard Specifications. We recommend that the suitability of structural fill soil from proposed borrow sources be evaluated by a representative of our firm before the earthwork contractor begins transporting the soil to the site. Reuse of On-site Soils On-site silty soils located within the upper few feet across the site will be difficult to reuse in the wet season or wet weather conditions. The silty soils should not be reused under the planned structures. The on-site sandy soils located above the water table may be used as structural fill in all areas during dry weather conditions (typically June through September), provided the material is properly moisture conditioned. Imported Gravel Borrow may be required for use as structural fill during wet weather conditions and during the wet season (typically October through May) if the on-site sandy soils cannot be properly moisture conditioned and compacted. The existing sandy soils are expected to be suitable for structural fill in areas requiring compaction to at least 95 percent of MDD (per ASTM D 1557), provided the work is accomplished during the normally dry season (June through September) and that the soil can be properly moisture conditioned to within 2 percent of the optimum moisture content. Concrete rubble and other debris must be removed from the existing fill soils before they can be reused as structural fill. Imported structural fill consisting of sand and gravel (WSDOT Gravel Borrow) should be planned under all building floor slabs and foundation elements and as wall backfill, especially if construction occurs during wet weather or the wet season (typically October through May). DRAFT May 18, 2018 | Page 17 File No. 23325-001-00 The contractor should plan to cover and maintain all stockpiles of on-site soil with plastic sheeting if it will be used as structural fill. The reuse of on-site soils is highly dependent on the skill of the contractor and the weather conditions, and we will work with the design team and contractor to maximize the reuse of on-site soils during the wet and dry seasons; however, imported gravel borrow should be planned for and specified for wet weather construction. Fill Placement and Compaction Criteria Structural fill should be mechanically compacted to a firm, non-yielding condition. Structural fill should be placed in loose lifts not exceeding 12 inches in thickness if using heavy compactors and 6 inches if using hand operated compaction equipment. The actual lift thickness will be dependent on the structural fill material used and the type and size of compaction equipment. Each lift should be moisture conditioned to within 2 percent of the optimum moisture content and compacted to the specified density before placing subsequent lifts. Structural fill should be compacted to the following criteria: ■ All fill placed under the proposed structures should be placed as structural fill compacted to at least 95 percent of the MDD estimated using the ASTM D 1557 test method. ■ Structural fill placed against foundations should be compacted to at least 95 percent of the MDD. ■ Structural fill placed behind below-grade walls should be compacted to between 90 to 92 percent of the MDD estimated using ASTM D 1557. Care should be taken when compacting fill near the face of below-grade walls to avoid over-compaction and hence overstressing the walls. Hand operated compactors should be used within 5 feet behind the wall. The upper 2 feet of fill below floor slab subgrade level should also be compacted to at least 95 percent of the MDD. The contractor should keep all heavy construction equipment away from the top of retaining walls a horizontal distance equal to half the height of the wall, or at least 5 feet, whichever is greater. ■ Structural fill in new pavement and hardscape areas, including utility trench backfill, should be compacted to at least 90 percent of the MDD, except that the upper 2 feet of fill below final subgrade level should be compacted to at least 95 percent of the MDD. ■ Structural fill placed as crushed surfacing base course below pavements should be compacted to 95 percent of the MDD. ■ Non-structural fill, such as fill placed in landscape areas, should be compacted to at least 90 percent of the MDD. An adequate number of in-place moisture and density tests should be performed during the placement and compaction of structural fill to evaluate whether the specified degree of compaction is being achieved. Weather Considerations Disturbance of near surface soils should be expected, especially if earthwork is completed during periods of wet weather. During dry weather, the soils will: (1) be less susceptible to disturbance; (2) provide better support for construction equipment; and (3) be more likely to meet the required compaction criteria. The wet weather season generally begins in October and continues through May in western Washington; however, periods of wet weather may occur during any month of the year. For earthwork activities during wet weather, we recommend the following steps be taken: DRAFT May 18, 2018 | Page 18 File No. 23325-001-00 ■ The ground surface in and around the work area should be sloped so that surface water is directed away from the work area. The ground surface should be graded so that areas of ponded water do not develop. Measures should be taken by the contractor to prevent surface water from collecting in excavations and trenches. Measures should be implemented to remove surface water from the work area. ■ Surface water must not be directed toward slopes and we recommend that storm water drainage ditches be constructed where needed along the crest of slopes to prevent uncontrolled surface water runoff. ■ Earthwork activities should not take place during periods of moderate to heavy precipitation. ■ Slopes with exposed soils should be covered with plastic sheeting. ■ The contractor should take necessary measures to prevent on-site soils and soils to be used as fill from becoming wet or unstable. These measures may include the use of plastic sheeting, sumps with pumps, and grading. The site soils should not be left uncompacted and exposed to moisture. Sealing the surficial soils by rolling with a smooth-drum roller prior to periods of precipitation will help reduce the extent that these soils become wet or unstable. ■ The contractor should cover all soil stockpiles that will be used as structural fill with plastic sheeting. ■ Construction traffic should be restricted to specific areas of the site, preferably areas that are surfaced with the existing asphalt or working pad materials not susceptible to wet weather disturbance. ■ Construction activities should be scheduled so that the length of time that soils are left exposed to moisture is reduced to the extent practical. Routing of equipment on the existing fill and native silty soils during the wet weather months will be difficult and the subgrade will likely become highly disturbed and rutted. In addition, a significant amount of mud can be produced by routing equipment directly on these soils in wet weather. Therefore, to protect the subgrade soils and to provide an adequate wet weather working surface for the contractor’s equipment and labor, we recommend that the contractor protect exposed subgrade soils with crushed rock or asphalt-treated base (ATB), as necessary. Temporary Cut Slopes For planning purposes, temporary unsupported cut slopes more than 4 feet high may be inclined at 1½H:1V in the fill and native soils. These inclinations may need to be flattened by the contractor if significant caving/sloughing or groundwater seepage occurs. For open cuts at the site, we recommend that: ■ No traffic, construction equipment, stockpiles, or building supplies be allowed at the top of cut slopes within a distance of at least 5 feet from the top of the cut; ■ The excavation not encroach on a 1H:1V influence line projected down from the edges of nearby or planned foundation elements; ■ Exposed soil along the slope be protected from surface erosion using waterproof tarps or plastic sheeting or flash coating with shotcrete; ■ Construction activities be scheduled so that the length of time the temporary cut is left open is reduced to the extent practicable; DRAFT May 18, 2018 | Page 19 File No. 23325-001-00 ■ Erosion control measures be implemented as appropriate such that runoff from the site is reduced to the extent practicable; ■ Surface water be diverted away from the excavation; and ■ The general condition of the slopes be observed periodically by GeoEngineers to confirm adequate stability. Because the contractor has control of the construction operations, the contractor should be made responsible for the stability of cut slopes, as well as the safety of the excavations. Shoring and temporary slopes must conform to applicable local, state and federal safety regulations. Permanent Cut and Fill Slopes We recommend that permanent cut or fill slopes be constructed at inclinations of 2H:1V or flatter and be blended into existing slopes with smooth transitions. To achieve uniform compaction, we recommend that fill slopes be overbuilt slightly and subsequently cut back to expose well compacted fill. To reduce erosion, newly constructed slopes and disturbed existing slopes should be planted or hydroseeded shortly after completion of grading. Until the vegetation is established, some sloughing and raveling of the slopes should be expected. This may necessitate localized repairs and reseeding. Temporary covering, such as clear heavy plastic sheeting, or erosion control blankets (such as American Excelsior Curlex 1 or North American Green SC150BN) could be used to protect the slopes during periods of rainfall. Erosion and Sediment Control In our opinion, the erosion potential of the on-site soils is low to moderate. Construction activities including stripping and grading will expose soils to the erosional effects of wind and water. The amount and potential impacts of erosion are partly related to the time of year that construction occurs. Wet weather construction will increase the amount and extent of erosion and potential sedimentation. Erosion and sedimentation control measures may be implemented by using a combination of interceptor swales, straw bale barriers, silt fences and straw mulch for temporary erosion protection of exposed soils. All disturbed areas should be finish graded and seeded as soon as practicable to reduce the risk of erosion. Utility Trenches Trench excavation, pipe bedding and trench backfilling should be completed using the general procedures described in the 2018 WSDOT Standard Specifications, or City of Renton requirements, or as specified by the project civil engineer. Utility trench backfill should consist of structural fill and should be placed in lifts of 12 inches or less (loose thickness) when using heavy compaction equipment, and 6 inches or less when using hand compaction equipment, such that adequate compaction can be achieved throughout the lift. Each lift must be compacted prior to placing the subsequent lift. Prior to compaction, the backfill should be moisture conditioned to within 2 percent of the optimum moisture content. The backfill should be compacted in accordance with the criteria discussed above. DRAFT May 18, 2018 | Page 20 File No. 23325-001-00 Pavement Recommendations Subgrade Preparation We recommend the subgrade soils in new pavement areas be prepared and evaluated as described in the “Earthwork” section of this report. Where existing fill is present, we recommend placing a 6-inch-thick imported granular subbase layer meeting the requirements of Gravel Borrow (Section 9-03.14(1) of the 2018 WSDOT Standard Specifications) below the pavement sections described below. If the subgrade soils are excessively loose or soft, it may be necessary to excavate localized areas and replace them with additional gravel borrow or gravel base material. Pavement subgrade conditions should be observed and proof-rolled during construction and prior to placing the subbase materials to evaluate the presence of unsuitable subgrade soils and the need for over-excavation and placement of a geotextile separator. The following pavement recommendations are for standard hot-mix asphalt (HMA) pavement designs. We understand that permeable pavement may be considered at the site. We can provide permeable pavement recommendations upon request. New Hot-Mix Asphalt Pavement In light-duty pavement areas (e.g., pedestrian access or passenger car parking), we recommend a pavement section consisting of at least a 3-inch thickness of ½-inch HMA (PG 58-22) per WSDOT Sections 5-04 and 9-03, over a 4-inch thickness of densely compacted crushed surfacing base course (CSBC) per WSDOT Section 9-03.9(3). In medium-duty pavement areas (e.g., drive aisles), we recommend a pavement section consisting of at least a 4-inch thickness of ½-inch HMA (PG 58-22) over a 6-inch thickness of densely compacted CSBC per WSDOT Section 9-03.9(3). The crushed surfacing base course in both light-duty and medium-duty areas should be compacted to at least 95 percent of the MDD (ASTM D 1557). We recommend that a proof-roll of the compacted base course be observed by a representative from our firm prior to paving. Soft or yielding areas observed during proof-rolling may require over-excavation and replacement with compacted structural fill. The pavement sections recommended above are based on our experience and typical traffic data provided by ARCO Murray. Thicker asphalt sections may be needed based on the actual projected traffic data, bus or truck loads, and intended use. Portland Cement Concrete Pavement Portland cement concrete (PCC) sections may be considered for loading dock aprons, trash dumpster areas and where other concentrated heavy loads may occur. For heavy-duty (e.g., service trucks, fire trucks, etc.) concrete paving, we recommend 8 inches of PCC overlying 6 inches of CSBC per WSDOT Section 9-03.9(3). The concrete thickness should be increased by the thickness of the reinforcing steel, if steel reinforcement is used. The crushed surface base course in both light duty and heavy-duty areas should be compacted to at least 95 percent of the MDD (ASTM D 1557). We recommend that a proof-roll of the compacted base course be observed by a representative from our firm prior to paving. Soft or yielding areas observed during proof-rolling may require over-excavation and replacement with compacted structural fill. DRAFT May 18, 2018 | Page 21 File No. 23325-001-00 We recommend PCC pavements incorporate construction joints and/or crack control joints spaced maximum distances of 12 feet apart, center-to-center, in both the longitudinal and transverse directions. Crack control joints may be created by placing an insert or groove into the fresh concrete surface during finishing, or by sawcutting the concrete after it has initially set-up. We recommend the depth of the crack control joints be approximately one-fourth the thickness of the concrete. We also recommend that the project team consider sealing crack control joints with an appropriate sealant to help restrict water infiltration into the joints. Construction Dewatering Static groundwater was observed in the borings at the time of exploration, as described in the “Groundwater Conditions” section of this report. Therefore, shallow excavations for utility trenches, underground vaults and elevator shafts may encounter groundwater. Dewatering during construction of these areas and other excavations on site may be required. Based on the soil conditions and our experience in the area, we expect that groundwater in excavations less than about 5 feet below existing grades can be controlled by open pumping using sump pumps. For excavations extending deeper and below the static ground water table dewatering using well points or deep wells will be necessary. We recommend that the contractor be required to submit a proposed dewatering system design and plan layout to the project team for review and comment prior to beginning construction. The level of effort required for dewatering will depend on the time of year during which construction is accomplished. Less seepage into the work areas and a lower water table should be expected if construction is accomplished in the late summer or early fall months, and correspondingly, more seepage and a higher water table should be expected during the wetter periods of the year and into the spring months. We recommend that earthwork activities be completed in the late summer or early fall months when precipitation is typically at its lowest. Infiltration Considerations The feasibility of infiltration was assessed at the site through review of near surface soil conditions and groundwater levels. Due to a relatively shallow groundwater table (4 feet below grade) and the presence of low permeability silt soils near the ground surface, we conclude that the use of large scale infiltration facilities is not feasible at this site. GeoEngineers can provide design infiltration rates for on-site best management practices (BMPs) such as permeable pavement or rain gardens, if required. Recommended Additional Geotechnical Services Throughout this report, recommendations are provided where we consider additional geotechnical services to be appropriate. These additional services are summarized below: ■ GeoEngineers should provide final design recommendations. ■ GeoEngineers can prepare construction drawings and specifications for ground improvement (such as stone columns or rigid inclusions) for the project, if requested. ■ GeoEngineers should be retained to review the project plans and specifications when complete to confirm that our design recommendations have been implemented as intended. DRAFT May 18, 2018 | Page 22 File No. 23325-001-00 ■ During construction, GeoEngineers should observe stripping and grading; observe and evaluate installation of ground improvement elements or deep foundations; observe and evaluate the suitability of foundation, wall and floor slab subgrades; observe removal of unsuitable fill and debris/rubble from below the building and parking garage footprints and hardscape areas; observe and test structural fill including wall and utility trench backfill; observe installation of subsurface drainage measures and infiltration facilities; evaluate the suitability of pavement subgrades and other appurtenant structures, and provide a summary letter of our construction observation services. The purposes of GeoEngineers’ construction phase services are to confirm that the subsurface conditions are consistent with those observed in the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, to evaluate whether or not earthwork and foundation installation activities are completed in accordance with our recommendations, and other reasons described in Appendix D, Report Limitations and Guidelines for Use. LIMITATIONS We have prepared this report for the exclusive use of ARCO Murray Design Build and their authorized agents for the Logan Avenue North and North 8th Street development project in Renton, Washington. Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in the field of geotechnical engineering in this area at the time this report was prepared. No warranty or other conditions, express or implied, should be understood. Any electronic form, facsimile or hard copy of the original document (email, text, table and/or figure), if provided, and any attachments are only a copy of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record. Please refer to Appendix D for additional information pertaining to use of this report. REFERENCES Al Atik, L. and N. Abrahamson (2010). “An Improved Method for Nonstationary Spectral Matching,” Earthquake Spectra, Vol. 26, No. 3, pp. 601-617. ASCE 7-10, 2010. “Minimum Design Loads for Buildings and Other Structures,” American Society of Civil Engineers ASTM D-1557, 2012. “Standard Testing Method for Laboratory Compaction Characteristics of Soil Using Modified Effort,” ASTM International Atkinson, G.M., Boore, D.M., 2003. “Empirical ground-motion relations for subduction-zone earthquakes and their application to Cascadia and other regions,” Bulletin of the Seismological Society of America, v. 93, n. 4, p. 1703-1729. Boore, D.M. and G.M. Atkinson, 2008. “Ground Motion Prediction Equations for the Average Horizontal Component of PGA, PGV, and 5% Damped PSA at Spectral Periods between 0.01s and 10.0 s.” Earthquake Spectra 24, 99-138. DRAFT May 18, 2018 | Page 23 File No. 23325-001-00 Campbell, K.W. and Y. Bozorgnia, 2008. “NGA Ground Motion Model for the Geometric Mean Horizontal Component of PGA, PGV, PGD and 5% Damped Linear Elastic Response Spectra for Periods Ranging from 0.01 to 10s.” Earthquake Spectra, Vol. 24, No. 1, 139-171. Chiou, B.S.J. and R.R. Youngs, 2008. “An NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra.” Earthquake Spectra, Vol. 24, No. 1, 173-215. City of Seattle, 2017, “Standard Specifications for Road, Bridge and Municipal Construction.” Darendeli, M., 2001. “Development of a new family of normalized modulus reduction and material damping curves.” Ph.D. Thesis, Dept. of Civil Eng., Univ. of Texas, Austin. Cetin, K.O., H.T. Bulge, J. Wu, A.M. Kammerer, and R.B. Seed 2009, “Probabilistic Model for the Assessment of Cyclically Induced Reconsolidation (Volumetric) Settlement.” Journal of Geotechnical and Geoenvironmental Engineering, 135(3), pp. 387-398. Fouad, L. and E.M. Rathje (2012). “RSPMatch09” http://nees.org/resources/rpsmatch09. Idriss, I. M., and R. W. Boulanger 2008. “Soil Liquefaction during Earthquakes.” Earthquake Engineering Research Institute MNO-12. International Code Council, 2015, “International Building Code.” Ishihara, K., and Yoshimine, M., “Evaluation of Settlements in Sand Deposits Following Liquefaction During Earthquakes,” Soils and Foundations, 32(1), 1992, pp. 173-188. Petersen, Mark D., Frankel, Arthur D., Harmsen, Stephen C., Mueller, Charles S., Haller, Kathleen M., Wheeler, Russell L., Wesson, Robert L., Zeng, Yuehua, Boyd, Oliver S., Perkins, David M., Luco, Nicolas, Field, Edward H., Wills, Chris J., and Rukstales, Kenneth S. (2008). Documentation for the 2008 Update of the United States National Seismic Hazard Maps: United States Geological Survey Open-File Report 2008-1128. Shahi, S.K. and J.K. Baker (2014). “NGA-West2 Models for Ground-Motion Directionality.” Earthquake Spectra, Vol. 30, No. 3, pp. 1285-1300. Tokimatsu K., Seed H.B., 1987. “Evaluation of settlements in sands due to earthquake shaking,” Journal of Geotechnical Engineering, 1987, vol. 113, pp. 861-878. USGS Unified Hazard Tool (Version Dynamic: Conterminous U.S. 2008) U.S. Geological Survey – National Seismic hazard Mapping project Software, “Earthquake Ground Motion Parameters, Version 5.0.9a,” 2002 data, 2009. Washington State Department of Transportation (WSDOT), 2018. “Standard Specifications for Road, Bridge, and Municipal Construction.” DRAFT May 18, 2018 | Page 24 File No. 23325-001-00 Wong, Ivan; Sparks, Andrew; Thomas, Patricia; Nemser, Eliza, 2003, Evaluation of near-surface site amplification in the Seattle, Washington, metropolitan area—Final technical report: Seismic Hazards Group, URS Corporation [under contract to] U.S. Geological Survey, 1 v. Youd, T. L. and Idriss, I. M. 2001. “Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils,” Journal of Geotechnical and Geoenvironmental Engineering, Vol. 127, No. 4, April 2001, pp. 298-313. Youngs, R.; Chiou, S-J.; Silva, W.; Humphrey, J. (1997). Strong ground motion attenuation relationships for subduction zone earthquakes. Seismological Research Letters 68. 58-73. Zhao J.X., Zhang, J., Asano, A., Ohno, Y., Oouchi, T., Takahashi, T., Ogawa, H., Irikura, K., Thio, H., Somerville, P., Fukushima, Y., and Fukushima, Y., 2006 Attenuation relations of strong ground motion in Japan using site classification based on predominant period: Bulletin of the Seismological Society of America, v. 96, p. 898–913. DRAFT µ SITE Vicinity Map Figure 1 Logan Avenue N/N 8th Street Development Renton, Washington 2,000 2,0000 Feet Data Source: Mapbox Open Street Map, 2018 Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended toassist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and contentof electronic files. The master file is stored by GeoEngineers,Inc. and will serve as the official record of this communication. Projection: NAD 1983 UTM Zone 10N P:\23\23325001\GIS\MXD\2332500100_F01_VicinityMap.mxd Date Exported: 04/25/18 by glohrmeyerDRAFT P P PP 28 28 303030303030 30 3030 30 323230303030 3 2 3 0 282830303030302828 2 8282 8 30 303029 31 29 29 29 292929 29 29 29 292929 292929 29 29 AB-1 CPT-1 B-1 OB-1 OB-6 B-2 OB-2 OB-3 AB-2 OB-4 PB-1 OB-5 OB-7 AB-3 GEI-2 GEI-1 CPT-2 CPT-3 CPT-4 CPT-5 CPT-6 N 8th St.Park Ave. NLogan Ave. NB' B A A' Figure 2 Logan Avenue N / N 8th Street Development Renton, Washington Site Plan W E N S P:\23\23325001\CAD\00\GeoTech\23325000100_F02-04_Site Plan and Cross-Sections.dwg TAB:F02 Date Exported: 05/17/18 - 12:39 by tmichaudLegend Property Boundary Boring by GeoEngineers, 2018 Notes: 1. The locations of all features shown are approximate. 2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication. Data Source: Site Survey by Axis Survey & Mapping, dated 04/23/18. Projection: WA State Plane, North Zone, NAD83, US Foot Feet 0100 100 AB-1, B-1, GEI-1, OB-1, PB-1 CPT-1 Cone Penetration Test by GeoEngineers, 2018 Cross-Section Location A A'DRAFT Elevation (Feet)Elevation (Feet)Distance (Feet) -60 -40 -20 0 20 40 -60 -40 -20 0 20 40 0 60 120 180 240 300 360 420 480 540 600 660 720 780 800OB-6(Offset 86 ft)OB-1(Offset 41 ft)PB-1(Offset 30 ft)OB-5(Offset 76 ft)CPT-1(Offset 20 ft)CPT-6(Offset 14 ft)25 8 3 6 3 3 4 SM GW-GM SMML SM ML SM 8 6 8 14 8 4 14 SM SMML SP-SM SM SP-SM PT SP-SM 13 2 2 3 4 5 19 14 SM SMSM SM ML ML ML SM SM 14 5 4 3 2 8 21 7 9 SM SM ML SP-SM OL PT SP-SM ML PT SM QT (tsf) 0 500 QT (tsf) 0 500 A (West) A' (East) Fill Loose to Medium Dense Alluvium Medium Dense to Dense Alluvium Figure 3 Logan Avenue N / N 8th Street Development Renton, Washington Cross-Section A-A'P:\23\23325001\CAD\00\GeoTech\23325000100_F02-04_Site Plan and Cross-Sections.dwg TAB:F03 Section AA Date Exported: 05/17/18 - 12:55 by tmichaudLegend Notes: 1. The subsurface conditions shown are based on interpolation between widely spaced explorations and should be considered approximate; actual subsurface conditions may vary from those shown. 2. This figure is for informational purposes only. It is intended to assist in the identification of features discussed in a related document. Data were compiled from sources as listed in this figure. The data sources do not guarantee these data are accurate or complete. There may have been updates to the data since the publication of this figure. This figure is a copy of a master document. The hard copy is stored by GeoEngineers, Inc. and will serve as the official document of record. Datum: NAVD 88, unless otherwise noted. SM 20 Boring Inferred Soil Contact Soil Classification Blow Count Legend EXPLORATION ID(Offset Distance)Fill Loose to Medium Dense Alluvium Medium Dense to Dense Alluvium Horizontal Scale in Feet 060 60 Vertical Scale in Feet 020 20 Vertical Exaggeration: 3X QT (tsf) 0 500EXPLORATION ID(Offset Distance)Cone Penetration Test Tip ResistanceDRAFT Elevation (Feet)Elevation (Feet)Distance (Feet) -60 -40 -20 0 20 40 -60 -40 -20 0 20 40 0 60 120 180 240 300 360 420 480 540 600 660 720 780 800OB-2(Offset 38 ft)OB-3(Offset 83 ft)OB-4(Offset 79 ft)OB-7(Offset 64 ft)CPT-2(Offset 10 ft)CPT-3(Offset 35 ft)CPT-5(Offset 13 ft)5 3 4 2 21 5 10 SM SP-SM MLML SM PT SM ML SM SP-SM 19 9 2 2 9 2 13 SM SW-SM SM PT SP-SM ML SP-SM 26 8 6 14 2 11 12 5 SM SP MHSMML SM SP-SM ML SP 19 5 1/12" 3 2 3 4 SM SMML SM MH SM MH ML SP MLPT QT (tsf) 0 500 QT (tsf) 0 500 QT (tsf) 0 500 B (Southwest) B' (Northeast) Fill Loose to Medium Dense Alluvium Medium Dense to Dense Alluvium Figure 4 Logan Avenue N / N 8th Street Development Renton, Washington Cross-Section B-B'P:\23\23325001\CAD\00\GeoTech\23325000100_F02-04_Site Plan and Cross-Sections.dwg TAB:F04 Section BB Date Exported: 05/17/18 - 12:55 by tmichaudNotes: 1. The subsurface conditions shown are based on interpolation between widely spaced explorations and should be considered approximate; actual subsurface conditions may vary from those shown. 2. This figure is for informational purposes only. It is intended to assist in the identification of features discussed in a related document. Data were compiled from sources as listed in this figure. The data sources do not guarantee these data are accurate or complete. There may have been updates to the data since the publication of this figure. This figure is a copy of a master document. The hard copy is stored by GeoEngineers, Inc. and will serve as the official document of record. Datum: NAVD 88, unless otherwise noted. Legend SM 20 Boring Inferred Soil Contact Soil Classification Blow Count Legend EXPLORATION ID(Offset Distance)Fill Loose to Medium Dense Alluvium Medium Dense to Dense Alluvium Horizontal Scale in Feet 060 60 Vertical Scale in Feet 020 20 Vertical Exaggeration: 3X QT (tsf) 0 500EXPLORATION ID(Offset Distance)Cone Penetration Test Tip ResistanceDRAFT 0.01 0.1 1 10 0.01 0.1 15% Damped Spectral Acceleration, Sa(g)Period (seconds) Recommended Site-Specific MCEr Response Spectrum Recommended Site-Specific MCERResponse Spectrum Logan Avenue N/N 8th Street Development Renton, Washington Figure 5 Project: 23325-001-00 Executed: 5/16/2018DRAFT 23325-001-00 Date Exported: 4/26/2018AXIAL PILE CAPACITY 18-inch Diameter General Notes 1. Assumed Liquefaction down to 55 feet bgs. 2. A downdrag load of 60 kips due to liquefaction should be considered in the pile loading. 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 0 200 400 600 800Depth (feet)Axial Resistance (kips) Uplift Resistance Ultimate Allowable 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 0 200 400 600 800Depth (feet)Axial Resistance (kips) Ultimate Downward Resistance Ultimate Side Friction Ultimate End Bearing Total Ultimate Resistance 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 0 200 400 600 800Depth (feet)Axial Resistance (kips) Allowable Downward Resistance Allowable Side Friction Allowable End Bearing Total Allowable Resistance 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 0 2,000 4,000Depth (feet)Subsurface Profile Fill Loose to M. Dense Alluvium M. Dense to Dense Alluvium Logan Avenue N/N 8th Street Development Renton, Washington Figure 6 Axial Capacity Plots 18-inch Augercast Pile (Building)DRAFT 23325-001-00 Date Exported: 4/26/2018AXIAL PILE CAPACITY 24-inch Diameter General Notes 1. Assumed Liquefaction down to 55 feet bgs. 2. A downdrag load of 80 kips due to liquefaction should be considered in the pile loading. 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 0 500 1,000 1,500Depth (feet)Axial Resistance (kips) Uplift Resistance Ultimate Allowable 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 0 500 1,000 1,500Depth (feet)Axial Resistance (kips) Ultimate Downward Resistance Ultimate Side Friction Ultimate End Bearing Total Ultimate Resistance 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 0 500 1,000 1,500Depth (feet)Axial Resistance (kips) Allowable Downward Resistance Allowable Side Friction Allowable End Bearing Total Allowable Resistance 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 0 2,000 4,000Depth (feet)Subsurface Profile Fill Loose to M. Dense Alluvium M. Dense to Dense Alluvium Logan Avenue N/N 8th Street Development Renton, Washington Figure 7 Axial Capacity Plots 24-inch Augercast Pile (Building)DRAFT APPENDIX A Field Explorations DRAFT May 18, 2018 | Page A-1 File No. 23325-001-00 APPENDIX A FIELD EXPLORATIONS Subsurface conditions were explored at the site by drilling fifteen borings (B-1, B-2, PB-1, AB-1 through AB-3, OB-1 through OB-7, GEI-1 and GEI-2) and advancing six cone penetration tests (CPTs) (CPT-1 through CPT-6) to depths ranging from approximately 10 to 82 feet below existing site grades. The borings were completed by Advanced Drill Technologies, Inc. from April 3 to April 4, 2018 and the CPTs were completed by In Situ Engineering on April 3, 2018. The locations of the explorations were estimated by taping/pacing from existing site features as well as surveyed. The approximate exploration locations are shown on the Figure 2, Site Plan. Borings The borings were completed using a D-50 track mounted drill rig with continuous-flight, hollow-stem auger drilling equipment. The borings were continuously monitored by a technician from our firm who examined and classified the soils encountered, obtained representative soil samples, observed groundwater conditions and prepared a detailed log of each exploration. The soils encountered in the borings were generally sampled at 2½- and 5-foot vertical intervals with a 2-inch, outside-diameter split-barrel standard penetration test (SPT) sampler. The disturbed samples were obtained by driving the sampler 18 inches into the soil with a 140-pound automatic hammer. The number of blows required for each 6 inches of penetration was recorded. The blow count ("N-value") of the soil was calculated as the number of blows required for the final 12 inches of penetration. This resistance, or N-value, provides a measure of the relative density of granular soils and the relative consistency of cohesive soils. Where very dense soil conditions precluded driving the full 18 inches, the penetration resistance for the partial penetration was entered on the logs. The blow counts are shown on the boring logs at the respective sample depths. Soils encountered in the borings were visually classified in general accordance with the classification system described in Figure A-1, Key to Exploration Logs. A key to the boring log symbols is also presented in Figure A-1. The logs of the borings are presented in Figures A-2 through A-16. The boring logs are based on our interpretation of the field and laboratory data and indicate the various types of soils and groundwater conditions encountered. The logs also indicate the depths at which these soils or their characteristics change, although the change may actually be gradual. If the change occurred between samples, it was interpreted. The densities noted on the boring logs are based on the blow count data obtained in the borings and judgment based on the conditions encountered. Observations of groundwater conditions were made during drilling. The groundwater conditions encountered during drilling are presented on the boring logs. Groundwater conditions observed during drilling represent a short-term condition and may or may not be representative of the long-term groundwater conditions at the site. Groundwater conditions observed during drilling should be considered approximate. Cone Penetration Tests The CPT is a subsurface exploration technique in which a small-diameter steel tip with adjacent sleeve is continuously advanced with hydraulically operated equipment. Measurements of tip and sleeve resistance DRAFT May 18, 2018 | Page A-2 File No. 23325-001-00 allow interpretation of the soil profile and the consistency of the strata penetrated. The tip resistance, friction ratio and pore water pressure are recorded on the CPT logs. The logs of the CPT probes are presented at the end of this appendix as Figures A-17 through A-22. The CPT soundings were backfilled in general accordance with procedures outlined by the Washington State Department of Ecology. DRAFT Measured groundwater level in exploration, well, or piezometer Measured free product in well or piezometer Distinct contact between soil strata Approximate contact between soil strata Contact between geologic units SYMBOLS TYPICAL DESCRIPTIONS GW GP SW SP SM FINE GRAINED SOILS SILTS AND CLAYS NOTE: Multiple symbols are used to indicate borderline or dual soil classifications MORE THAN 50% RETAINED ON NO. 200 SIEVE MORE THAN 50% PASSING NO. 200 SIEVE GRAVEL AND GRAVELLY SOILS SC LIQUID LIMIT LESS THAN 50 (APPRECIABLE AMOUNT OF FINES) (APPRECIABLE AMOUNT OF FINES) COARSE GRAINED SOILS MAJOR DIVISIONS GRAPH LETTER GM GC ML CL OL SILTS AND CLAYS SANDS WITH FINES SAND AND SANDY SOILS MH CH OH PT (LITTLE OR NO FINES) CLEAN SANDS GRAVELS WITH FINES CLEAN GRAVELS (LITTLE OR NO FINES) WELL-GRADED GRAVELS, GRAVEL -SAND MIXTURES CLAYEY GRAVELS, GRAVEL - SAND -CLAY MIXTURES WELL-GRADED SANDS, GRAVELLYSANDS POORLY-GRADED SANDS, GRAVELLYSAND SILTY SANDS, SAND - SILT MIXTURES CLAYEY SANDS, SAND - CLAYMIXTURES INORGANIC SILTS, ROCK FLOUR,CLAYEY SILTS WITH SLIGHTPLASTICITY INORGANIC CLAYS OF LOW TOMEDIUM PLASTICITY, GRAVELLYCLAYS, SANDY CLAYS, SILTY CLAYS,LEAN CLAYS ORGANIC SILTS AND ORGANIC SILTYCLAYS OF LOW PLASTICITY INORGANIC SILTS, MICACEOUS ORDIATOMACEOUS SILTY SOILS INORGANIC CLAYS OF HIGHPLASTICITY ORGANIC CLAYS AND SILTS OFMEDIUM TO HIGH PLASTICITY PEAT, HUMUS, SWAMP SOILS WITHHIGH ORGANIC CONTENTSHIGHLY ORGANIC SOILS SOIL CLASSIFICATION CHART MORE THAN 50% OF COARSE FRACTION RETAINED ON NO. 4 SIEVE MORE THAN 50% OF COARSE FRACTION PASSING ON NO. 4 SIEVE SILTY GRAVELS, GRAVEL - SAND -SILT MIXTURES POORLY-GRADED GRAVELS,GRAVEL - SAND MIXTURES LIQUID LIMIT GREATER THAN 50 Continuous Coring Bulk or grab Direct-Push Piston Shelby tube Standard Penetration Test (SPT) 2.4-inch I.D. split barrel Contact between soil of the same geologic unit Material Description Contact Graphic Log Contact NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurface conditions. Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made; they are not warranted to be representative of subsurface conditions at other locations or times. Groundwater Contact Blowcount is recorded for driven samplers as the number of blows required to advance sampler 12 inches (or distance noted). See exploration log for hammer weight and drop. "P" indicates sampler pushed using the weight of the drill rig. "WOH" indicates sampler pushed using the weight of the hammer. Key to Exploration Logs Figure A-1 Sampler Symbol Descriptions ADDITIONAL MATERIAL SYMBOLS NS SS MS HS No Visible Sheen Slight Sheen Moderate Sheen Heavy Sheen Sheen Classification SYMBOLS Asphalt Concrete Cement Concrete Crushed Rock/ Quarry Spalls Topsoil GRAPH LETTER AC CC SOD Sod/Forest Duff CR DESCRIPTIONS TYPICAL TS Laboratory / Field Tests %F %G AL CA CP CS DD DS HA MC MD Mohs OC PM PI PP SA TX UC VS Percent fines Percent gravel Atterberg limits Chemical analysis Laboratory compaction test Consolidation test Dry density Direct shear Hydrometer analysis Moisture content Moisture content and dry density Mohs hardness scale Organic content Permeability or hydraulic conductivity Plasticity index Pocket penetrometer Sieve analysis Triaxial compression Unconfined compression Vane shearDRAFT 2315 40 48 PP = 0 psf PP = 0 psf AL (LL = 35, PI = 5) Groundwater observed at approximately 10 feet below ground surface during drilling PP = 0 psf Added drilling mud at 20 feet; no heave observed PP = 0 psf AL (LL = 47, PI = 10) PP = 500 psf Topsoil Gray sandy silt with occasional gravel (stiff, moist) (fill) Brown silty fine to medium sand with gravel (medium dense, moist to wet) Gray silty fine sand (very loose, moist) (alluvium) Gray silt with trace fine sand (very soft to soft, moist) Gray silty fine sand (very loose, moist to wet) Brown-gray silt (very soft to soft, wet) Gray silty fine sand with occasional silt lenses (loose to medium dense, wet) Gray fine to medium sand with silt (loose to medium dense, wet) Brown silt with organic matter and occasional horizontal bedding (stiff, moist) Gray silty fine sand (medium dense, wet) With organic matter (wood debris), becomes very loose Brown-gray silt (soft, moist) Gray-light brown silt with organic matter (wood debris) (medium stiff, moist) Gray fine sand with silt and occasional organic matter (wood debris) (loose, moist) 1 2 SA 3a 3b 3c 4a 4b AL 5a 5b 6a 6b 6c 7 8 9 AL 10a 10b 4 18 7 6 12 18 18 18 18 16 2 2 10 12 23 3 6 TS ML SM SM ML SM ML SM SP-SM ML SM ML ML SP-SM Notes: 4/4/2018 4/4/2018 61.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301051.97 183599.31 29.5 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 2Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring B-1 Logan Avenue N/N 8th Street Development Figure A-2 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 30 35 Graphic LogGroupClassificationElevation (feet)2520151050-5DRAFT 204 159 PP = 6,500 psf PP = 500 psf PP = 4,500 - 6,000 psf Gravels at 55 feet Broken cobble in shoe Gray fine to coarse sand with trace silt (loose, wet) Brown fibrous peat (soft to medium stiff, moist) Brown-gray silt (soft to medium stiff, moist) With occasional peat lenses, becomes medium stiff Brown fibrous peat with silt lenses (medium stiff, moist) Gray silty fine to medium sand with peat lenses (loose, moist) Gray silty fine to coarse sand with occasional gravel (dense, moist) 11 12a MC 12b 13b 13a MC 14 15 16 11 18 18 18 10 0 7 4 6 6 44 25 SP-SM PT ML PT SM SM Sheet 2 of 2Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring B-1 (continued) Logan Avenue N/N 8th Street Development Figure A-2 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35 40 45 50 55 60 Graphic LogGroupClassificationElevation (feet)-10-15-20-25-30DRAFT 15 6 10 35 38 61 PP = 500 psf AL (LL = 35, PI = 5) Groundwater observed at approximately 8½ feet below ground surface during drilling AL (LL = 117, PI = 33) AL (LL = 78, PI = 15) Topsoil Brown silty fine to coarse sand with gravel (loose, moist) (fill) Becomes medium dense Gray silty fine sand (very loose, wet) (alluvium) Gray sandy silt (very soft to soft, wet) Brown silty fine sand (very loose, wet) Brown-gray sandy organic silt (very soft to soft, moist to wet) Gray fine to coarse sand (dense, wet) Gray silty fine sand (dense, moist) Gray fine sand with trace silt (medium dense, moist) Gray silty fine to medium sand (loose, moist) Light brown elastic silt with occasional peat (medium stiff, moist) Becomes gray and soft to medium stiff Gray fine sand with silt (very loose to loose, moist) 1 MC 2 SA 3 4 AL 5 6 AL 7a 7b 8 9a 9b AL 10a 10b 18 16 18 18 18 18 18 7 10 24 2 2 2 33 23 6 4 TS SM SM ML SM OH SP SM SP-SM SM MH SM Notes: 4/4/2018 4/4/2018 36.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301086.5 183468.47 30 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 2Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring B-2 Logan Avenue N/N 8th Street Development Figure A-3 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 30 35 Graphic LogGroupClassificationElevation (feet)2520151050-5DRAFT Gray-brown fine to medium sand with brown silt lenses and occasional organic matter (wood debris) (loose, moist) 11128 SP Sheet 2 of 2Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring B-2 (continued) Logan Avenue N/N 8th Street Development Figure A-3 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35 Graphic LogGroupClassificationElevation (feet)DRAFT 9 83 5 9 39 PP = 0 psf Groundwater observed at approximately 9 feet below ground surface during drilling Approximately 6 inches of asphalt concrete pavement Gravel base Brown silty fine to coarse sand with gravel (loose, moist) (fill) Brown fine to coarse sand with silt and gravel (medium dense, moist) Gray silt with sand (very soft to soft, moist) (alluvium) Gray medium to coarse sand with silt (medium dense, wet) Gray fine to medium sand (loose, wet) 1 MC 2 SA 3 %F 4 5 11 18 18 18 24 2 11 7 AC GP SM SP-SM ML SP-SM SM Notes: 4/3/2018 4/3/2018 11.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1300893.96 183685.04 30 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring AB-1 Logan Avenue N/N 8th Street Development Figure A-4 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 Graphic LogGroupClassificationElevation (feet)2520DRAFT 27 13 9 81 39 PP = 500 - 1,000 psf AL (LL = 37, PI = 7) Grass Brown silty fine to coarse sand with gravel and organic matter (roots, wood debris) (loose, moist) (fill) Brown silty fine to medium sand with occasional gravel (dense, moist) Brown-gray fine to coarse sand with silt (medium dense, dry) Brown peat with silt (medium stiff, moist) (alluvium) Gray sandy silt with occasional peat lenses (medium stiff, moist) Gray silty fine to medium sand (medium dense, wet) 1 MC 2 SA 3 4a MC 4b AL 5 18 18 16 33 22 6 19 Grass SM SM SP-SM PT ML SM Notes: 4/3/2018 4/3/2018 11.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301034.62 183259 31 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method Groundwater not observed at time of exploration Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring AB-2 Logan Avenue N/N 8th Street Development Figure A-5 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 Graphic LogGroupClassificationElevation (feet)302520DRAFT 16 12 16 Groundwater observed at approximately 4½ feet below ground surface during drilling PP = 0 psf Topsoil Brown-orange silty fine to coarse sand with occasional gravel (loose, moist) (fill) Becomes orange fine to medium and medium dense Becomes loose Gray fine to medium sand with trace silt (loose, wet) (alluvium) Brown-gray sandy silt (very soft, moist) Becomes medium stiff Gray silty fine sand (loose, moist) 1 MC 2 SA 3a 3b 4 5a 5b 16 18 16 18 7 1 6 TS SM SP-SM ML SM Notes: 4/4/2018 4/4/2018 11.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301930.66 183629.16 29.5 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring AB-3 Logan Avenue N/N 8th Street Development Figure A-6 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 Graphic LogGroupClassificationElevation (feet)2520DRAFT 9 10 7 37 Groundwater observed at approximately 4½ feet below ground surface during drilling PP = 3,000 - 4,000 psf PP = 500 psf AL (non-plastic) Topsoil Brown silty fine to coarse sand with gravel (loose, moist) (fill) Brown fine to coarse gravel with silt and sand (medium dense, moist) Gray silty fine sand with oxidation staining (loose, moist) (alluvium) Gray silt with trace fine sand (medium stiff, moist) Gray silty fine to medium sand (very loose, wet) Grades to fine to coarse, becomes loose Gray sandy silt (soft, wet) Gray silty fine sand (very loose to loose, wet) 1 MC 2 SA 3 4 5 6 7a 7b AL 8 1 18 6 18 16 18 18 25 8 3 6 3 3 4 TS SM GW-GM SM ML SM ML SM Notes: 4/3/2018 4/3/2018 26.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301187.33 183663.85 29 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring OB-1 Logan Avenue N/N 8th Street Development Figure A-7 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 Graphic LogGroupClassificationElevation (feet)252015105DRAFT 9 157 Groundwater observed at approximately 4 feet below ground surface during drilling PP = 1,000 - 1,500 psf Topsoil Brown-gray silty fine to coarse sand with gravel and organic matter (grass roots) (loose, moist) (fill) Brown-orange fine to coarse sand with silt and gravel (loose, moist) Gray silt with fine sand and occasional peat, orange oxidation staining (soft, moist) (alluvium) Brown sandy silt with oxidation staining (soft, wet) Gray silty fine sand (very loose to loose, wet) Peat with interbedded silt (very soft to soft, moist) Gray silty fine sand (medium dense, moist) Gray silt with fine sand and occasional organic matter (wood debris) (medium stiff, moist) Gray silty fine sand (loose, moist) Gray fine to medium sand with silt (loose to medium dense, moist) 1 MC 2 3a 3b 4 5a 5b MC 6 7a 7b 8 18 18 18 18 18 18 18 5 3 4 2 21 5 10 TS SM SP-SM ML ML SM PT SM ML SM SP-SM Notes: 4/3/2018 4/3/2018 26.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301213.57 183432.09 29 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring OB-2 Logan Avenue N/N 8th Street Development Figure A-8 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 Graphic LogGroupClassificationElevation (feet)252015105DRAFT 1013 32 170 63 PP = 500 psf AL (non-plastic) PP = 0 psf PP = 500 psf AL (LL = 100, PI = 32) Grass Gray-brown silty fine to coarse sand with gravel and organic matter (roots) (loose, moist) (fill) Brown fine to medium sand with silt and gravel, orange oxidation staining (medium dense, moist) Gray silty fine sand (loose, moist) (alluvium) Becomes very loose, wet Brown peat with interbedded silt (very soft to soft, wet) Gray fine sand with silt (stiff, wet) Gray silt with occasional organic matter (roots) (very soft to soft, wet) Gray fine to moist sand with trace silt (medium dense, wet) 1 2 SA 3a 3b 4 AL 5a 5b MC 6 7a 7b AL 8 18 18 18 18 18 18 18 19 9 2 2 9 2 13 Grass SM SW-SM SM PT SP-SM ML SP-SM Notes: 4/3/2018 4/3/2018 26.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301271.62 183492.16 29 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method Groundwater not observed at time of exploration Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring OB-3 Logan Avenue N/N 8th Street Development Figure A-9 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 Graphic LogGroupClassificationElevation (feet)252015105DRAFT 5 29 PP = 3,000 psf AL (LL = 54, PI = 19) PP = 0 psf Topsoil Brown silty fine to coarse sand with gravel (loose, moist) (fill) Brown-orange fine to medium sand with silt (medium dense, moist) Becomes gray and loose Gray sandy elastic silt (medium stiff to stiff, moist)(alluvium) Gray silty fine to medium sand (loose, wet) Gray silt with fine sand (medium stiff, wet) Gray silty fine sand (medium dense, wet) Gray fine to medium sand with silt (very loose, wet) Sandy silt (very soft to soft, wet) Gray fine to medium sand with trace silt (mediumdense, wet) Becomes loose 1 MC 2 3a 3b AL 4a 4b 5 6a 6b 7 8 9 12 12 16 18 18 18 18 18 26 8 6 14 2 11 12 5 TS SM SP MH SM ML SM SP-SM ML SP Notes: 4/4/2018 4/4/2018 31.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301466.88 183532.18 29 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method Groundwater not observed at time of exploration Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring OB-4 Logan Avenue N/N 8th Street Development Figure A-10 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 30 Graphic LogGroupClassificationElevation (feet)2520151050DRAFT 1314 PP = 4,000 - 5,000 psf PP = 0 - 500 psf Groundwater observed at approximately 9½ feet below ground surface during drilling Grass Brown silty fine to medium sand with gravel (loose, moist) (fill) Becomes brown to orange Orange silty fine sand with trace gravel (loose, wet) (alluvium) Gray silt with occasional organic matter (roots) (medium stiff, moist) Gray fine sand with silt (loose, wet) Becomes medium dense Gray silty fine to coarse sand (loose, wet) Gray fine to medium sand with trace silt (very loose to loose, wet) Peat (soft to medium stiff, moist) Gray fine to coarse sand with trace silt and occasional gravel (medium dense, wet) 1 2 SA 3a 3b 4 5 6a 6b 7a 7b 8 18 16 18 18 18 18 18 8 6 8 14 8 4 14 Grass SM SM ML SP-SM SM SP-SM PT SP-SM Notes: 26.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301551.57 183625.75 29 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring OB-5 Logan Avenue N/N 8th Street Development Figure A-11 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 Graphic LogGroupClassificationElevation (feet)252015105DRAFT 46 11 36 PP = 0 - 500 psf PP = 0 psf PP = 0 psf Added drilling mud at 25 feet; 12 inches of heave observed Topsoil Brown silty fine to coarse sand with occasional gravel and organic matter (grass roots) (loose, moist) (fill) Gray silty fine sand with occasional organic matter (roots) (medium dense, wet) Brown-orange fine to coarse sand with gravel (very loose, wet) Gray silty fine sand (very loose, moist to wet) (alluvium) Gray sandy silt with peat lenses and organic matter (wood debris) (soft, moist) Gray sandy silt with trace organic matter (roots) (soft, wet) Gray silt with trace fine sand and organic matter (roots, wood debris) (soft to medium stiff, wet) Gray silty fine to medium sand (loose, wet) Becomes fine sand Gray silty fine to medium sand (medium dense, wet) 1 MC 2 3a 3b %F 4 5a 5b 5c 6 7a 7b 8 9 4 18 18 18 18 18 18 18 13 2 2 3 4 5 19 14 TS SM SM SM SM ML ML ML SM SM Notes: 4/3/2018 4/3/2018 31.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301256.48 183619.06 29 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method Groundwater not observed at time of exploration Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring OB-6 Logan Avenue N/N 8th Street Development Figure A-12 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 30 Graphic LogGroupClassificationElevation (feet)2520151050DRAFT 61 10 30 50 PP = 0 - 500 psf PP = 500 psf Groundwater observed at approximately 8¼ feet below ground surface during drilling PP = 0 psf AL (LL = 53, PI = 10) Topsoil Gray silty fine to coarse sand with gravel and organic matter (roots) (loose, moist) (fill) Gray silty fine to coarse sand with gravel (medium dense, moist) Gray sandy silt (medium stiff, wet) (alluvium) Gray silty fine to medium sand (loose, wet) Gray sandy elastic silt (very soft, wet) Gray silty fine to medium sand (very loose, wet) Gray sandy elastic silt with peat lenses (very soft to soft, moist) Brown sandy silt (soft, moist) Gray fine to medium sand (very loose, wet) Becomes very loose to loose Gray-brown silt with organic matter (roots) (soft to medium stiff, moist) Peat with silt lenses (soft to medium stiff, moist) 1 MC 2 3a %F 3b 4a 4b 5 6a 6b AL 7a 7b 8a 8b 8c 14 18 18 18 18 18 18 19 5 1/12" 3 2 3 4 TS SM SM ML SM MH SM MH ML SP ML PT Notes: 4/4/2018 4/4/2018 26.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301664.46 183562.89 29 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring OB-7 Logan Avenue N/N 8th Street Development Figure A-13 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 Graphic LogGroupClassificationElevation (feet)252015105DRAFT 72 6 36 52 Groundwater observed at approximately 12½ feet below ground surface during drilling AL (LL = 93, PI = 33) PP = 0 - 500 psf Topsoil Brown silty fine to coarse gravel with sand (loose, moist) (fill) Brown silty fine to coarse sand with occasional gravel (medium dense, moist) Gray silt with fine to coarse sand lenses (very stiff, moist) (alluvium) Orange fine to medium sand with trace gravel (medium dense, moist) Gray silt with sand (medium stiff, moist) Becomes stiff, wet Gray silty fine to medium sand (loose, wet) Gray sandy silt with thin lens of peat (medium stiff to stiff, wet) Gray fine to medium sand with trace silt (loose, wet) Gray-brown silt with peat lenses (very soft to soft, moist) With occasional organic matter (wood debris, roots) Gray fine to medium sand (medium dense, wet) 1 MC 2a 2b 2c 3 %F 4 5 6a 6b 7a AL 7b 8 14 18 18 6 18 18 18 18 6 13 5 8 2 16 TS GM SM ML SP ML SM ML SP-SM ML SP Notes: 4/4/2018 4/4/2018 26.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301655.17 183321.6 30 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring GEI-1 Logan Avenue N/N 8th Street Development Figure A-14 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 Graphic LogGroupClassificationElevation (feet)252015105DRAFT 11 12 13 PP = 500 psf Groundwater observed at approximately 8 feet below ground surface during drilling PP = 500 psf Topsoil Gray silty fine to coarse sand with gravel (loose, moist) (fill) Gray fine to medium sand with silt and gravel (medium dense, moist) Becomes very loose, wet Gray sandy silt (very soft to soft, wet) (alluvium) Gray silt with fine sand (very soft, wet) Light gray-brown silt with thin peat lenses (very soft, wet) Gray silty fine to medium sand (loose, wet) 1 MC 2 SA 3a 3b 4a 4b 5 18 18 18 18 18 2 1/12" 5 TS SM SP-SM ML ML ML SM Notes: 4/4/2018 4/4/2018 11.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301918.15 183394.24 30 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 1Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring GEI-2 Logan Avenue N/N 8th Street Development Figure A-15 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 Graphic LogGroupClassificationElevation (feet)2520DRAFT 16 73 11 34 100 Groundwater observed at approximately 6¼ feet below ground surface during drilling PP = 500 psf PP = 0 psf AL (LL = 120, PI = 33) Added drilling mud at 20 feet; 13 inches of heave observed Topsoil Brown silty fine to coarse sand with gravel and organic matter (roots) (loose, moist) (fill) Becomes medium dense Gray silty fine to coarse sand (loose, wet) (alluvium) With gravel, becomes very loose to loose Gray silt with sand (soft to medium stiff, wet) Gray fine to medium sand with silt (very loose, wet) Brown organic silt with organic matter (roots) (very soft to soft, wet) Brown-dark brown fibrous peat with silt lenses (medium stiff to stiff, moist) Gray silty fine sand (loose, moist to wet) Gray fine to coarse sand with trace silt (medium dense, wet) 1 2 SA 3a 3b 4a 4b 5 %F 6a 6b AL 7a 7b 8 9 6 5 8 18 18 18 18 0 14 5 4 3 2 8 21 7 TS SM SM ML SP-SM OL PT SM SP-SM Notes: 4/3/2018 4/3/2018 36.5 NS LA Advance Drill Technologies, Inc.Hollow-stem Auger Diedrich D50 drill rigDrilling EquipmentAutohammer 140 (lbs) / 30 (in) Drop WA State Plane North NAD83 (feet) 1301443.78 183732.69 29 NAVD88 Easting (X) Northing (Y) Surface Elevation (ft) Vertical Datum Drilled Start End Total Depth (ft) Logged By Checked By Hammer Data System Datum Driller Drilling Method See "Remarks" section for groundwater observed Note: See Figure A-1 for explanation of symbols. Coordinates Data Source: Horizontal approximated based on locational survey. Vertical approximated based on topographic survey. Sheet 1 of 2Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring PB-01 Logan Avenue N/N 8th Street Development Figure A-16 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)0 5 10 15 20 25 30 35 Graphic LogGroupClassificationElevation (feet)2520151050-5DRAFT 216 PP = 0 psfGray silt with fine sand and organic matter (peat, wood debris) (loose, wet) Dark brown fibrous peat with occasional silt (stiff, moist) 10a 10b MC 16 9 ML PT Sheet 2 of 2Project Number: Project Location: Project: Renton, Washington 23325-001-00 Log of Boring PB-01 (continued) Logan Avenue N/N 8th Street Development Figure A-16 Date:5/18/18 Path:C:\USERS\TNASH\DESKTOP\2332500100.GPJ DBLibrary/Library:GEOENGINEERS_DF_STD_US_JUNE_2017.GLB/GEI8_GEOTECH_STANDARD_%F_NO_GWFinesContent (%)MoistureContent (%)REMARKS FIELD DATA MATERIAL DESCRIPTION Sample NameTestingRecovered (in)IntervalBlows/footCollected SampleDepth (feet)35 Graphic LogGroupClassificationElevation (feet)DRAFT APPENDIX B Laboratory Testing DRAFT May 18, 2018 | Page B-1 File No. 23325-001-00 APPENDIX B LABORATORY TESTING Soil samples obtained from the explorations were transported to GeoEngineers’ laboratory and evaluated to confirm or modify field classifications, as well as to evaluate engineering properties of the soil samples. Representative samples were selected for laboratory testing to determine percent fines (material passing the U.S. No. 200 sieve) and gradation test (sieve analysis). The tests were performed in general accordance with test methods of ASTM International (ASTM) or other applicable procedures. Moisture Content Moisture content tests were completed in general accordance with ASTM D 2216 for representative samples obtained from the explorations. The results of these tests are presented on the exploration logs in Appendix A at the depths at which the samples were obtained. Percent Passing U.S. No. 200 Sieve (%F) Selected samples were “washed” through the U.S. No. 200 mesh sieve to estimate the relative percentages of coarse- and fine-grained particles in the soil. The percent passing value represents the percentage by weight of the sample finer than the U.S. No. 200 sieve. These tests were conducted to verify field descriptions and to estimate the fines content for analysis purposes. The tests were conducted in general accordance with ASTM D 1140, and the results are shown on the exploration logs in Appendix A at the respective sample depths. Sieve Analyses Sieve analyses were performed on selected samples in general accordance with ASTM D 422. The wet sieve analysis method was used to determine the percentage of soil greater than the U.S. No. 200 mesh sieve. The results of the sieve analyses were plotted, were classified in general accordance with the Unified Soil Classification System (USCS) and are presented in Figures B-1 through B-3, Sieve Analysis Results. Atterberg Limits We completed Atterberg limits tests on selected fine-grained soil samples. We used the test results to classify the soil as well as to evaluate index properties and consolidation characteristics. Liquid limits, plastic limits and plasticity index were obtained in general accordance with ASTM Test Method D 4318. Results of the Atterberg limits tests are summarized in Figures B-4 through B-7. DRAFT 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000PERCENT PASSING BY WEIGHT GRAIN SIZE IN MILLIMETERS U.S. STANDARD SIEVE SIZE SAND SILT OR CLAYCOBBLES GRAVEL COARSE MEDIUM FINECOARSEFINE Boring Number Depth (feet)Soil Description B-1 B-2 AB-1 AB-2 2.5 2.5 2.5 2.5 Silty fine to medium sand with gravel (SM) Silty fine to coarse sand with gravel (SM) Fine to coarse sand with silt and gravel (SP-SM) Silty fine to medium sand with occasional gravel (SM) Symbol Moisture (%) 15 10 9 9 3/8”3”1.5”#4 #10 #20 #40 #60 #1003/4”Figure B-1Sieve Analysis ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington023325-001-00 Date Exported: 04/18/18 Note:This report may not be reproduced,except in full,without written approval of GeoEngineers,Inc.Test results are applicable only to the specific sample on which they were performed,and should not be interpreted as representative of any other samples obtained at other times,depths or locations,or generated by separate operations or processes. The grain size analysis results were obtained in general accordance with ASTM D 6913. #200 DRAFT 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000PERCENT PASSING BY WEIGHT GRAIN SIZE IN MILLIMETERS U.S. STANDARD SIEVE SIZE SAND SILT OR CLAYCOBBLES GRAVEL COARSE MEDIUM FINECOARSEFINE Boring Number Depth (feet)Soil Description AB-3 OB-1 OB-3 OB-5 2.5 2.5 2.5 2.5 Silty fine to medium sand with occasional gravel (SM) Fine to coarse gravel with silt and sand (GW-GM) Fine to medium sand with silt and gravel (SW-SM) Silty fine to medium sand with gravel (SM) Symbol Moisture (%) 16 7 13 14 3/8”3”1.5”#4 #10 #20 #40 #60 #1003/4”Figure B-2Sieve Analysis ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington023325-001-00 Date Exported: 04/18/18 Note:This report may not be reproduced,except in full,without written approval of GeoEngineers,Inc.Test results are applicable only to the specific sample on which they were performed,and should not be interpreted as representative of any other samples obtained at other times,depths or locations,or generated by separate operations or processes. The grain size analysis results were obtained in general accordance with ASTM D 6913. #200 DRAFT 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.11101001000PERCENT PASSING BY WEIGHT GRAIN SIZE IN MILLIMETERS U.S. STANDARD SIEVE SIZE SAND SILT OR CLAYCOBBLES GRAVEL COARSE MEDIUM FINECOARSEFINE Boring Number Depth (feet)Soil Description GEI-2 PB-01 2.5 2.5 Fine to medium sand with silt and gravel (SP-SM) Silty fine to coarse sand with gravel (SM) Symbol Moisture (%) 13 11 3/8”3”1.5”#4 #10 #20 #40 #60 #1003/4”Figure B-3Sieve Analysis ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington023325-001-00 Date Exported: 04/18/18 Note:This report may not be reproduced,except in full,without written approval of GeoEngineers,Inc.Test results are applicable only to the specific sample on which they were performed,and should not be interpreted as representative of any other samples obtained at other times,depths or locations,or generated by separate operations or processes. The grain size analysis results were obtained in general accordance with ASTM D 6913. #200 DRAFT Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes. The liquid limit and plasticity index were obtained in general accordance with ASTM D 4318.Figure B-4Atterberg Limits Test ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington023325-001-00 Date Exported: 04/18/18SymbolBoringNumberDepth(feet)Moisture Content(%)Liquid Limit(%)Plasticity Index(%)Soil DescriptionB-1B-1B-2B-27.5277.51540483538354735117510533Silt (ML)Silt (ML)Sandy silt (ML)Sandy organic silt (OH)01020304050600 102030405060708090100110120PLASTICITY INDEX LIQUID LIMITPLASTICITY CHARTCL-MLML or OLCL or OLOH or MHCH or OHDRAFT Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes. The liquid limit and plasticity index were obtained in general accordance with ASTM D 4318.Figure B-5Atterberg Limits Test ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington023325-001-00 Date Exported: 04/18/18SymbolBoringNumberDepth(feet)Moisture Content(%)Liquid Limit(%)Plasticity Index(%)Soil DescriptionB-2AB-2OB-1OB-3257.5207.5613937327837NPNP157NPNPElastic silt (MH)Sandy silt (ML)Sandy silt (non-plastic) (ML)Silty fine sand (non-plastic) (SM)01020304050600 102030405060708090100PLASTICITY INDEX LIQUID LIMITPLASTICITY CHARTCL-MLML or OLCL or OLOH or MHCH or OHDRAFT Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes. The liquid limit and plasticity index were obtained in general accordance with ASTM D 4318.Figure B-6Atterberg Limits Test ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington023325-001-00 Date Exported: 04/18/18SymbolBoringNumberDepth(feet)Moisture Content(%)Liquid Limit(%)Plasticity Index(%)Soil DescriptionOB-3OB-4OB-7GEI-120515206329505210054539332191033Silt with organic matter (ML)Sandy elastic silt (MH)Sandy elastic silt (MH)Silt with peat lenses (ML)01020304050600 102030405060708090100PLASTICITY INDEX LIQUID LIMITPLASTICITY CHARTCL-MLML or OLCL or OLOH or MHCH or OHDRAFT Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes. The liquid limit and plasticity index were obtained in general accordance with ASTM D 4318.Figure B-7Atterberg Limits Test ResultsLogan Avenue N/N 8thStreet DevelopmentRenton, Washington023325-001-00 Date Exported: 04/18/18SymbolBoringNumberDepth(feet)Moisture Content(%)Liquid Limit(%)Plasticity Index(%)Soil DescriptionPB-0115100 12033 Organic silt (OH)01020304050600 102030405060708090100110120PLASTICITY INDEX LIQUID LIMITPLASTICITY CHARTCL-MLML or OLCL or OLOH or MHCH or OHDRAFT APPENDIX C Site-Specific Seismic Response Analysis DRAFT May 18, 2018 | Page C-1 File No. 23325-001-00 APPENDIX C SITE-SPECIFIC SEISMIC RESPONSE ANALYSIS Nonlinear site response analyses were completed using the computer software FLAC (Fast Lagrangian Analysis of Continua) developed by Itasca of Minneapolis, Minnesota. The purpose of the nonlinear site response analyses is to evaluate site-specific soil amplification factors (AFs) and develop site-specific risk- targeted maximum-considered earthquake (MCER) response spectra based on ASCE 7-10 (2010) using the following approach: 1. Complete a site-specific probabilistic seismic hazard analyses (PSHA) to compute rock outcrop uniform hazard spectra (UHS) for the maximum-considered earthquake (MCE) (2 percent probability of exceedance in 50 years, 2,475-year return period). Rock outcrop conditions are defined as the Site Class B/C boundary or Vs30=760 meters per second (m/sec). 2. Complete seismic hazard deaggregation for the 2,475-year event at the periods of interest and select a suite of seven acceleration time histories that represent the contributing seismic sources to the total hazard at the site. 3. Modify the frequency content of the time histories via spectral matching to match the input time history response spectra to the target rock outcrop response spectra. 4. Develop shear wave velocity profiles and one-dimensional (1D) soil models based on the shear wave velocity measurements obtained at the site and its vicinity and using subsurface information collected from the geotechnical explorations completed at the site. 5. Complete nonlinear site response analyses to compute the soil response spectra at ground surface and calculate site-specific soil AFs. 6. Evaluate maximum component adjustment (MCA) factors and risk coefficients per ASCE 7-10 Section 21.2.1.2. 7. Develop probabilistic MCER ground motions by multiplying the probabilistic MCE ground motions from (1) by the site-specific soil AFs, MCA factors, and risk coefficients. 8. Develop deterministic MCER ground motions per ASCE 7-10 by evaluating the 84th percentile maximum direction deterministic response spectrum including the MCA factors. 9. Develop the recommended site-specific MCER response spectrum by taking the lesser of the probabilistic and deterministic MCER response spectra and comparing it to 80 percent of the ASCE 7-10 code-based response spectrum. Rock Outcrop Uniform Hazard Spectrum A site-specific PSHA was completed using the computer code Haz45.2 to develop the rock outcrop uniform hazard spectrum. Relevant seismic sources based on the 2014 United States Geological Survey (USGS) seismic source characterization (SSC) model were considered for the project. The 2014 USGS SSC model contains seismic source characteristics and recurrence models developed by USGS for the 2014 update of the National Seismic Hazard Maps (Petersen et al. 2014). The UHS for the 2,475-year event was computed for rock outcrop conditions (i.e. Site Class B/C boundary, Vs30=760 m/sec). The suite of ground motion models (GMMs) and corresponding weights that were used to complete the PSHA are presented in Table C-1 below. Table C-2 presents the 2,475-year rock outcrop UHS. DRAFT May 18, 2018 | Page C-2 File No. 23325-001-00 TABLE C-1. GROUND MOTION MODELS AND WEIGHTS Earthquake Source Ground Motion Prediction Equations Weight Crustal Abrahamson et al. (2014) [ASK14] 0.250 Boore et al. (2014) [BSSA14] 0.250 Campbell and Bozorgnia (2014) [CB14] 0.250 Chiou and Youngs (2014) [CY14] 0.250 Cascadia Subduction Zone Benioff/Intraslab Atkinson and Boore – Global Subduction (2003, 2008) [AB08-G] 0.167 Atkinson and Boore – Cascadia Subduction (2003, 2008) [AB08-C] 0.167 Zhao et al. (2006) [Z06] 0.333 BC Hydro – Global (Abrahamson et al. 2016) 0.234 BC Hydro – Cascadia (Abrahamson et al. 2016) 0.099 Cascadia Subduction Zone Interface Atkinson and Boore – Global Subduction (2003, 2008) 0.100 Zhao et al. (2006) 0.300 BC Hydro – Global (Abrahamson et al. 2016) 0.600 TABLE C-2. 2,475-YEAR UNIFORM HAZARD SPECTRUM (2,475-YEAR, VS30 = 760 M/SEC) Period (sec) Target Rock Outcrop 0.01 0.651 0.05 0.962 0.075 1.256 0.1 1.486 0.2 1.507 0.3 1.198 0.4 0.989 0.5 0.820 0.75 0.578 1 0.439 2 0.200 3 0.113 4 0.074 5 0.051 Selection of Input Acceleration Time Histories The seismic hazard deaggregation was performed at a spectral period (T) of 1.0 and 2.0 seconds to evaluate the percent contribution of the various source-types to the uniform hazard associated with the 2,475-year earthquake event. The deaggregation results are presented in Table C-3. Based on the results, four crustal events, one subduction-intraslab event, and two subduction-interface events were selected to represent the 2,475-year event. Table C-4 summarizes the 2,475-year record suite used. DRAFT May 18, 2018 | Page C-3 File No. 23325-001-00 TABLE C-3. MCE SEISMIC HAZARD DEAGGREGATION (VS30=760 M/SEC) Earthquake Source Percent Contribution to Hazard at T=1.0 sec T=2.0 sec Crustal 63 52 Subduction Zone – Intraslab 13 13 Subduction Zone – Interface 24 35 TABLE C-4. INPUT EARTHQUAKE TIME HISTORIES FOR 2,475-YEAR EVENT SITE RESPONSE ANALYSIS Earthquake Type Mw Station Distance (km) Tabas Iran, 1978 Crustal (Reverse) 7.4 Tabas 2.1 Loma Prieta, 1989 Crustal (Reverse Oblique) 6.9 Saratoga – Aloha Ave 8.5 Niigata Japan, 2004 Crustal (Reverse) 6.6 NIGH11 8.9 Taiwan SMART1 (45), 1986 Crustal (Reverse) 7.3 SMART1 E02 51.4 El Salvador, 2001 Subduction Intraslab 7.6 Santa Tecia - Maule, 2010 Subduction-Interface 8.8 Concepcion San Pedro (CCSP) 82.4 Tohoku, 2011 Subduction-Interface 9.0 Ujiie_TCGH12 299.0 Ground Motion Modification The suites of input acceleration time histories were modified via spectral matching to match the target rock outcrop 2,475-year response spectra from T=0.01 to 5.0 seconds. Spectral matching was completed using RSPMatch09 (Fouad et al. 2012) based on the improved spectral matching approach proposed by Al Atik, et al. (2010). The ground motions were processed with a Butterworth low pass filter to filter out frequencies greater than 25 Hertz. The as-recorded and spectrally matched response spectra are presented in Figures C-1 and C-2. One-Dimensional Soil Models Shear wave velocity (Vs) profiles were developed using measurements collected the site, and shear wave velocity data for alluvium soils to account for the variability and uncertainty in the dynamic properties of the soil. In-situ measurements were collected at two CPT locations (CPT-1 and CPT-2). Additionally, shear wave velocity measurements for Alluvium soils were collected as part of the nearby Project Impact (Wong et al. 2003). We developed shear wave velocity profiles based on the in-situ measurements from CPTs, correlations with SPT measurements from the borings completed at the site, and shear wave velocity data for alluvium soils from a nearby study. Uncertainty in the shear wave velocity profile was incorporated into the analysis by considering the difference between the CPT in-situ measurements and the shear wave velocity measurements within alluvium soils, completed nearby. Two shear wave velocity profiles, lower bound (LB), and upper bound (UB), were developed to capture the range of the measured shear wave velocity of the soils to account for the uncertainty in the shear wave velocity of the subsurface soils encountered at the DRAFT May 18, 2018 | Page C-4 File No. 23325-001-00 site. The two profiles developed are presented in Figures C-3 and C-4, for depths extending to 100 feet (shallow) and 400 feet (deep), respectively. Table C-5 summarizes the soil type, layer depth, soil unit weight, plasticity index (PI), and shear modulus reduction (G/Gmax) and damping curves used in the representative FLAC 1D soil model. TABLE C-5. ONE-DIMENSIONAL SOIL MODEL Soil Type Depth (feet) Soil Unit Weight (pcf) Plasticity Index G/Gmax and Damping Curves Alluvium 1 0 to 10 100 0 Darendeli (2001) Alluvium 2 10 to 50 110 0 Darendeli (2001) Alluvium 3 50 to 60 120 0 Darendeli (2001) Alluvium 4 60 to 170 125 0 Darendeli (2001) Alluvium 5 170 to 400 125 0 Darendeli (2001) Notes: pcf – pounds per cubic foot Site-Specific Amplification Factors Site-specific soil AFs were computed for a 2,475-year event using the following approach: 1. Compute ground surface response spectra by propagating the suite of ground motions upward through the LB and UB 1D soil models. 2. Compute lower bound and upper bound soil AFs as the average of the ratio of the ground surface response spectra and the input rock outcrop response spectra for each ground motion suite. 3. Evaluate site-specific soil AFs as the weighted-average of the LB and UB soil AFs by assigning 0.5 weights to both LB and UB soil profiles. Figures C-5 and C-6 present the individual and average soil AFs computed for the LB and UB profiles for the 2,475-year event, respectively. Figure C-7 presents the recommended site-specific soil AFs. Figure C-8 presents the effect of site amplification by comparing the probabilistic MCE before (target rock outcrop UHS) and after applying the recommended site-specific soil AFs (MCER). Maximum Component Adjustment Factors and Risk Coefficients Per ASCE 7-10, the probabilistic and deterministic MCER ground motions are to be taken in the direction of maximum horizontal response. MCA factors are used to convert the geometric mean spectral ordinates to spectral ordinates that correspond to the direction of maximum horizontal response. The MCA factors per Shahi and Baker (2014) were used for this evaluation. Risk coefficients are used to convert the probabilistic MCE ground motions (2 percent probability of exceedance in 50 years) to MCER ground motions, which correspond to a 1 percent probability of collapse in 50 years. Risk coefficients were calculated according to Section 21.2.1.2 of ASCE 7-10 using a MATLAB script provided to us by Nico Luco of USGS. The risk coefficients were computed based on the seismic hazard curves based on the average Vs30 calculated from the ground surface. Table C-6 presents the MCA factors and the risk coefficients. DRAFT May 18, 2018 | Page C-5 File No. 23325-001-00 TABLE C-6. MAXIMUM COMPONENT ADJUSTMENT FACTORS AND RISK COEFFICIENTS Period (sec) Maximum Component Adjustment Factor Risk Coefficients 0.010 1.19 0.96 0.050 1.19 0.96 0.075 1.19 0.96 0.100 1.19 0.96 0.200 1.21 0.98 0.300 1.22 0.99 0.400 1.23 0.97 0.500 1.23 0.95 0.750 1.24 0.93 1.000 1.24 0.92 2.000 1.24 0.89 3.000 1.25 0.91 4.000 1.26 0.89 5.000 1.26 0.89 Deterministic (MCER) Ground Motions Deterministic MCER ground motions were evaluated per ASCE 7-10 Section 21.2.2. Figure C-9 presents the development of the crustal deterministic (MCER) response spectrum. Based on our experience in the area, crustal ground motions generally govern when computing deterministic response spectrum, hence only the crustal deterministic response spectrum is presented. The deterministic response spectrum was developed by computing the 84th percentile response spectrum for rock outcrop conditions for the Seattle Fault (MW=7.2, RRUP=2.9 km) with the average Vs30=143 m/sec using four equally-weighted NGA-West2 GMMs (ASK14, BSSA14, CB14, and CY14) (dashed gray lines [individual GMMs] and solid red line [weighted average]). Lastly, MCA factors were applied to convert the deterministic response spectrum (weighted average) to the direction of maximum horizontal response (solid black line presented in Figure C-9). Probabilistic (MCER) Ground Motions Probabilistic MCER ground motions were evaluated per ASCE 7-10 Section 21.2.1. Probabilistic MCER ground motions were computed by first multiplying the target rock outcrop UHS (Probabilistic MCE) by the recommended MCA factors and risk coefficients. Lastly, soil AFs were applied to compute the probabilistic MCER (dashed black line in Figure C-10). Recommended Site-Specific MCER Response Spectrum The recommended site-specific MCER response spectrum was developed by taking the lesser of the probabilistic and deterministic MCER response spectra and comparing it to 80 percent of the ASCE 7-10 Site Class E MCER response spectrum (allowable code minimum) (Figure C-10). The recommended site- specific MCER response spectrum is a smoothed version of the site-specific MCER response spectrum and code spectrum. Table C-7 presents the recommended site-specific response spectrum. DRAFT May 18, 2018 | Page C-6 File No. 23325-001-00 TABLE C-7. RECOMMENDED SITE-SPECIFIC MCER RESPONSE SPECTRUM Period (s) MCER Response Spectrum 0.01 0.49 0.05 0.70 0.075 0.79 0.10 0.86 0.20 1.04 0.30 1.04 0.40 1.04 0.50 1.04 0.75 1.04 1.00 1.04 2.00 0.68 3.00 0.40 4.00 0.26 5.00 0.21 DRAFT 0.01 0.1 1 10 0.01 0.1 15% Damped Spectral Acceleration, Sa (g)Period (seconds) M7.35 Tabas_Iran L1 (Reverse) [C] M6.9 Loma Prieta - Saratoga - Aloha Ave (Reverse Oblique) [C] M6.63 Niigata_Japan, NIGH11 (Reverse) M7.3 Taiwan SMART1(45) - SMART1 E02 (Reverse) [C] M9.0 Tohoku -Ujiie_TCGH12_EW [IF] M8.8 Chile - Concepcion San Pedro_CCSP_NS M7.6 El Salvador - Santa Tecia_ST_NS [IS] 2475-year UHS (Vs30=760 m/sec) Average of 7 Input Ground Motions As-recorded Response Spectra 2475-year Event Logan Avenue N/N 8th Street Development Renton, Washington Figure C-1 Legend Crustal Event Interface Subduction Zone Event IntraslabSubduction Zone Event [C] [IF] [IS]Project: 23325-001-00 Executed: 05/16/2018DRAFT 0.01 0.1 1 10 0.01 0.1 15% Damped Spectral Acceleration, Sa (g)Period (seconds) M7.35 Tabas_Iran L1 (Reverse) [C] M6.9 Loma Prieta - Saratoga - Aloha Ave (Reverse Oblique) [C] M6.63 Niigata_Japan, NIGH11 (Reverse) M7.3 Taiwan SMART1(45) - SMART1 E02 (Reverse) [C] M9.0 Tohoku -Ujiie_TCGH12_EW [IF] M8.8 Chile - Concepcion San Pedro_CCSP_NS M7.6 El Salvador - Santa Tecia_ST_NS [IS] 2475-year UHS (Vs30=760 m/sec) Average of 7 Input Ground Motions Spectrally Matched and Filtered Response Spectra Logan Avenue N/N 8th Street Development Renton, Washington Figure C-2 Legend Crustal Event Interface Subduction Zone Event IntraslabSubduction Zone Event [C] [IF] [IS]Project: 00694-040-00 Executed: 02/14/2018DRAFT 0 10 20 30 40 50 60 70 80 90 100 0 500 1000 1500 2000 2500 3000 Depth (ft)Vs (ft/s) B-1 Correlated Vs Data B-2 Correlated Vs Data CPT-1 Vs Data CPT-2 Vs Data Generalized Vs (LB) Profile Generalized Vs (UB) Profile Shear Wave Velocity Profiles - Shallow Logan Avenue N/N 8th Street Development Renton, Washington Figure C-3 Project: 23325-001-00Exec uted: 05-16-2018DRAFT 0 50 100 150 200 250 300 350 400 450 0 500 1000 1500 2000 2500 3000 Depth (ft)Vs (ft/s) B-1 Correlated Vs Data B-2 Correlated Vs Data CPT-1 Vs Data CPT-2 Vs Data Generalized Vs (LB) Profile Generalized Vs (UB) Profile Shear Wave Velocity Profiles - Deep Logan Avenue N/N 8th Street Development Renton, Washington Figure C-4 Project:23325-001-00 Executed: 05/16/2018DRAFT 0 1 2 3 4 5 6 0.01 0.1 1Amplification Factor, Surface Sa/ Rock Outcrop SaPeriod (seconds) M7.35 Tabas_Iran L1 (Reverse) [C] M6.9 Loma Prieta - Saratoga - Aloha Ave (Reverse Oblique) [C] M6.63 Niigata_Japan, NIGH11 (Reverse) M7.3 Taiwan SMART1(45) - SMART1 E02 (Reverse) [C] M9.0 Tohoku -Ujiie_TCGH12_EW [IF] M8.8 Chile - Concepcion San Pedro_CCSP_NS M7.6 El Salvador - Santa Tecia_ST_NS [IS] Average Amplification Factor, Lower Bound Profile Soil Amplification Factor, Lower Bound Profile 2475-year Event Logan Avenue N/N 8th Street Development Renton, Washington Figure C-5 Legend Crustal Event Interface Subduction Zone Event IntraplateSubduction Zone Event (Bennioff) [C] [IF] [IP]Project: 23325‐001‐00 Executed: 05/16/2018DRAFT 0 1 2 3 4 5 6 0.01 0.1 1Amplification Factor, Surface Sa/ Rock Outcrop SaPeriod (seconds) M7.35 Tabas_Iran L1 (Reverse) [C] M6.9 Loma Prieta - Saratoga - Aloha Ave (Reverse Oblique) [C] M6.63 Niigata_Japan, NIGH11 (Reverse) M7.3 Taiwan SMART1(45) - SMART1 E02 (Reverse) [C] M9.0 Tohoku -Ujiie_TCGH12_EW [IF] M8.8 Chile - Concepcion San Pedro_CCSP_NS M7.6 El Salvador - Santa Tecia_ST_NS [IS] Average Amplification Factor, Upper Bound Profile Soil Amplification Factors, Upper Bound Profile 2475-year Event Logan Avenue N/N 8th Street Development Renton, Washington Figure C-6 Legend Crustal Event Interface Subduction Zone Event IntraplateSubduction Zone Event (Bennioff) [C] [IF] [IP]Project: 23325‐001‐00 Executed: 05/16/2018DRAFT 0 1 2 3 4 5 6 0.01 0.1 1Amplification Factor, Surface Sa/ Rock Outcrop SaPeriod (seconds) Average Amplification Factor, Lower Bound Profile Average Amplification Factor, Upper Bound Profile Recommended Weighted Average Amplification Factor (Site Specific) Soil Amplification Factors Profile Comparison 2475-year Event Logan Avenue N/N 8th Street Development Renton, Washington Figure C-7 Project: 23325‐001‐00 Executed: 05/16/2018DRAFT 0.01 0.1 1 10 0.01 0.1 15% Damped Spectral Acceleration, Sa(g)Period (seconds) Target Rock Outcrop UHS Target Rock Outcrop UHS x Site Specific Soil Amplification Factors Probabilistic MCE Response Spectrum Comparison Logan Avenue N/N 8th Street Development Renton, Washington Figure C-8 Project: 23325-001-00 Executed: 05/16/2018DRAFT 0.01 0.1 1 10 0.01 0.1 15% Damped Spectral Acceleration, Sa(g)Period (seconds) ASK14 (No-Basin) BSSA14 (No-Basin) CB14 (No-Basin) CY14 (No-Basin) Weighted-Avg. Det (Crustal) Weighted-Avg. Det + Basin Amplification Factors + Max. Component Adj. Factors (Crustal) Deterministic MCER Response Spectrum (Seattle Fault, Mw=7.2, Rrup=2.9 km) Logan Avenue N/N 8th Street Development Renton, Washington Figure C-9 Project: 23325-001-00 Executed: 5/16/2018DRAFT 0.01 0.1 1 10 0.01 0.1 15% Damped Spectral Acceleration, Sa(g)Period (seconds) ASCE 7-10 Site Class E MCEr 0.8 x ASCE 7-10 Site Class E MCEr Deterministic (MCE) Response Spectrum Site-Specific Probabilistic MCEr Response Spectrum Recommended Site-Specific MCEr Response Spectrum Recommended Site-Specific MCERResponse Spectrum Logan Avenue N/N 8th Street Development Renton, Washington Figure C-10 Project: 23325-001-00 Executed: 5/16/2018DRAFT APPENDIX D Report Limitations and Guidelines for Use DRAFT May 18, 2018 | Page D-1 File No. 23325-001-00 APPENDIX D REPORT LIMITATIONS AND GUIDELINES FOR USE1 This appendix provides information to help you manage your risks with respect to the use of this report. Geotechnical Services Are Performed for Specific Purposes, Persons and Projects This report has been prepared for the exclusive use of ARCO Murray Design Build and other project team members for the Logan Avenue North and North 8th Street development project. This report is not intended for use by others, and the information contained herein is not applicable to other sites. GeoEngineers structures our services to meet the specific needs of our clients. For example, a geotechnical or geologic study conducted for a civil engineer or architect may not fulfill the needs of a construction contractor or even another civil engineer or architect that are involved in the same project. Because each geotechnical or geologic study is unique, each geotechnical engineering or geologic report is unique, prepared solely for the specific client and project site. Our report is prepared for the exclusive use of our Client. No other party may rely on the product of our services unless we agree in advance to such reliance in writing. This is to provide our firm with reasonable protection against open-ended liability claims by third parties with whom there would otherwise be no contractual limits to their actions. Within the limitations of scope, schedule and budget, our services have been executed in accordance with our Agreement with the Client and generally accepted geotechnical practices in this area at the time this report was prepared. This report should not be applied for any purpose or project except the one originally contemplated. A Geotechnical Engineering or Geologic Report Is Based on a Unique Set of Project-specific Factors This report has been prepared for the Logan Avenue North and North 8th Street development project in Renton, Washington. GeoEngineers considered a number of unique, project-specific factors when establishing the scope of services for this project and report. Unless GeoEngineers specifically indicates otherwise, do not rely on this report if it was: ■ not prepared for you, ■ not prepared for your project, ■ not prepared for the specific site explored, or ■ completed before important project changes were made. For example, changes that can affect the applicability of this report include those that affect: ■ the function of the proposed structure; ■ elevation, configuration, location, orientation or weight of the proposed structure; 1 Developed based on material provided by ASFE, Professional Firms Practicing in the Geosciences; www.asfe.org . DRAFT May 18, 2018 | Page D-2 File No. 23325-001-00 ■ composition of the design team; or ■ project ownership. If important changes are made after the date of this report, GeoEngineers should be given the opportunity to review our interpretations and recommendations and provide written modifications or confirmation, as appropriate. Subsurface Conditions Can Change This geotechnical or geologic report is based on conditions that existed at the time the study was performed. The findings and conclusions of this report may be affected by the passage of time, by manmade events such as construction on or adjacent to the site, or by natural events such as floods, earthquakes, slope instability or groundwater fluctuations. Always contact GeoEngineers before applying a report to determine if it remains applicable. Most Geotechnical and Geologic Findings Are Professional Opinions Our interpretations of subsurface conditions are based on field observations from widely spaced sampling locations at the site. Site exploration identifies subsurface conditions only at those points where subsurface tests are conducted or samples are taken. GeoEngineers reviewed field and laboratory data and then applied our professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ, sometimes significantly, from those indicated in this report. Our report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions. Geotechnical Engineering Report Recommendations Are Not Final Do not over-rely on the preliminary construction recommendations included in this report. These recommendations are not final, because they were developed principally from GeoEngineers’ professional judgment and opinion. GeoEngineers’ recommendations can be finalized only by observing actual subsurface conditions revealed during construction. GeoEngineers cannot assume responsibility or liability for this report's recommendations if we do not perform construction observation. Sufficient monitoring, testing and consultation by GeoEngineers should be provided during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not earthwork activities are completed in accordance with our recommendations. Retaining GeoEngineers for construction observation for this project is the most effective method of managing the risks associated with unanticipated conditions. A Geotechnical Engineering or Geologic Report Could Be Subject to Misinterpretation Misinterpretation of this report by other design team members can result in costly problems. You could lower that risk by having GeoEngineers confer with appropriate members of the design team after submitting the report. Also retain GeoEngineers to review pertinent elements of the design team's plans and specifications. Contractors can also misinterpret a geotechnical engineering or geologic report. Reduce that risk by having GeoEngineers participate in pre-bid and preconstruction conferences, and by providing construction observation. DRAFT May 18, 2018 | Page D-3 File No. 23325-001-00 Do Not Redraw the Exploration Logs Geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation of field logs and laboratory data. To prevent errors or omissions, the logs included in a geotechnical engineering or geologic report should never be redrawn for inclusion in architectural or other design drawings. Only photographic or electronic reproduction is acceptable, but recognize that separating logs from the report can elevate risk. Give Contractors a Complete Report and Guidance Some owners and design professionals believe they can make contractors liable for unanticipated subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems, give contractors the complete geotechnical engineering or geologic report, but preface it with a clearly written letter of transmittal. In that letter, advise contractors that the report was not prepared for purposes of bid development and that the report's accuracy is limited; encourage them to confer with GeoEngineers and/or to conduct additional study to obtain the specific types of information they need or prefer. A pre-bid conference can also be valuable. Be sure contractors have sufficient time to perform additional study. Only then might an owner be in a position to give contractors the best information available, while requiring them to at least share the financial responsibilities stemming from unanticipated conditions. Further, a contingency for unanticipated conditions should be included in your project budget and schedule. Contractors Are Responsible for Site Safety on Their Own Construction Projects Our geotechnical recommendations are not intended to direct the contractor’s procedures, methods, schedule or management of the work site. The contractor is solely responsible for job site safety and for managing construction operations to minimize risks to on-site personnel and to adjacent properties. Read These Provisions Closely Some clients, design professionals and contractors may not recognize that the geoscience practices (geotechnical engineering or geology) are far less exact than other engineering and natural science disciplines. This lack of understanding can create unrealistic expectations that could lead to disappointments, claims and disputes. GeoEngineers includes these explanatory “limitations” provisions in our reports to help reduce such risks. Please confer with GeoEngineers if you are unclear how these “Report Limitations and Guidelines for Use” apply to your project or site. Geotechnical, Geologic and Environmental Reports Should Not Be Interchanged The equipment, techniques and personnel used to perform an environmental study differ significantly from those used to perform a geotechnical or geologic study and vice versa. For that reason, a geotechnical engineering or geologic report does not usually relate any environmental findings, conclusions or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Similarly, environmental reports are not used to address geotechnical or geologic concerns regarding a specific project. DRAFT May 18, 2018 | Page D-4 File No. 23325-001-00 Biological Pollutants GeoEngineers’ Scope of Work specifically excludes the investigation, detection, prevention or assessment of the presence of Biological Pollutants. Accordingly, this report does not include any interpretations, recommendations, findings, or conclusions regarding the detecting, assessing, preventing or abating of Biological Pollutants and no conclusions or inferences should be drawn regarding Biological Pollutants, as they may relate to this project. The term “Biological Pollutants” includes, but is not limited to, molds, fungi, spores, bacteria, and viruses, and/or any of their byproducts. If Client desires these specialized services, they should be obtained from a consultant who offers services in this specialized field. DRAFT APPENDIX C CSWPP WORKSHEETS APPENDIX D WWHM2012 INPUT AND OUTPUT WWHM2012 PROJECT REPORT DRAFTTopgolf West Basin Tank Sizing_190424 4/24/2019 5:26:53 PM Page 2 General Model Information Project Name:Topgolf West Basin Tank Sizing_190424 Site Name:Topgolf Site Address: City:Renton Report Date:4/24/2019 Gage:Seatac Data Start:1948/10/01 00:00 Data End:2009/09/30 00:00 Timestep:15 Minute Precip Scale:1.000 Version Date:2018/10/10 Version:4.2.16 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year DRAFTTopgolf West Basin Tank Sizing_190424 4/24/2019 5:26:53 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 2.88 Pervious Total 2.88 Impervious Land Use acre ROADS FLAT 1.76 Impervious Total 1.76 Basin Total 4.64 Element Flows To: Surface Interflow Groundwater DRAFTTopgolf West Basin Tank Sizing_190424 4/24/2019 5:26:53 PM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 1.43 Pervious Total 1.43 Impervious Land Use acre ROADS FLAT 2.55 ROOF TOPS FLAT 0.66 Impervious Total 3.21 Basin Total 4.64 Element Flows To: Surface Interflow Groundwater Tank 1 Tank 1 DRAFTTopgolf West Basin Tank Sizing_190424 4/24/2019 5:26:53 PM Page 6 Mitigated Routing Tank 1 Dimensions Depth:5 ft. Tank Type:Circular Diameter:5 ft. Length:380 ft. Discharge Structure Riser Height:4.5 ft. Riser Diameter:24 in. Orifice 1 Diameter:3.0938 in.Elevation:0 ft. Orifice 2 Diameter:4.4844 in.Elevation:2.95 ft. Orifice 3 Diameter:2.8281 in.Elevation:3.75 ft. Element Flows To: Outlet 1 Outlet 2 Tank Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.000 0.000 0.000 0.000 0.0556 0.009 0.000 0.061 0.000 0.1111 0.012 0.001 0.086 0.000 0.1667 0.015 0.001 0.106 0.000 0.2222 0.018 0.002 0.122 0.000 0.2778 0.020 0.003 0.136 0.000 0.3333 0.021 0.004 0.150 0.000 0.3889 0.023 0.006 0.162 0.000 0.4444 0.024 0.007 0.173 0.000 0.5000 0.026 0.008 0.183 0.000 0.5556 0.027 0.010 0.193 0.000 0.6111 0.028 0.012 0.203 0.000 0.6667 0.029 0.013 0.212 0.000 0.7222 0.030 0.015 0.220 0.000 0.7778 0.031 0.017 0.229 0.000 0.8333 0.032 0.018 0.237 0.000 0.8889 0.033 0.020 0.244 0.000 0.9444 0.034 0.022 0.252 0.000 1.0000 0.034 0.024 0.259 0.000 1.0556 0.035 0.026 0.266 0.000 1.1111 0.036 0.028 0.273 0.000 1.1667 0.036 0.030 0.280 0.000 1.2222 0.037 0.032 0.287 0.000 1.2778 0.038 0.034 0.293 0.000 1.3333 0.038 0.036 0.299 0.000 1.3889 0.039 0.038 0.306 0.000 1.4444 0.039 0.041 0.312 0.000 1.5000 0.040 0.043 0.318 0.000 1.5556 0.040 0.045 0.324 0.000 1.6111 0.040 0.047 0.329 0.000 1.6667 0.041 0.050 0.335 0.000 1.7222 0.041 0.052 0.340 0.000 1.7778 0.041 0.054 0.346 0.000 1.8333 0.042 0.056 0.351 0.000 1.8889 0.042 0.059 0.357 0.000 1.9444 0.042 0.061 0.362 0.000 DRAFTTopgolf West Basin Tank Sizing_190424 4/24/2019 5:26:53 PM Page 7 2.0000 0.042 0.064 0.367 0.000 2.0556 0.042 0.066 0.372 0.000 2.1111 0.043 0.068 0.377 0.000 2.1667 0.043 0.071 0.382 0.000 2.2222 0.043 0.073 0.387 0.000 2.2778 0.043 0.076 0.392 0.000 2.3333 0.043 0.078 0.396 0.000 2.3889 0.043 0.080 0.401 0.000 2.4444 0.043 0.083 0.406 0.000 2.5000 0.043 0.085 0.410 0.000 2.5556 0.043 0.088 0.415 0.000 2.6111 0.043 0.090 0.419 0.000 2.6667 0.043 0.092 0.424 0.000 2.7222 0.043 0.095 0.428 0.000 2.7778 0.043 0.097 0.432 0.000 2.8333 0.043 0.100 0.437 0.000 2.8889 0.043 0.102 0.441 0.000 2.9444 0.042 0.104 0.445 0.000 3.0000 0.042 0.107 0.571 0.000 3.0556 0.042 0.109 0.631 0.000 3.1111 0.042 0.112 0.677 0.000 3.1667 0.042 0.114 0.716 0.000 3.2222 0.041 0.116 0.751 0.000 3.2778 0.041 0.119 0.782 0.000 3.3333 0.041 0.121 0.812 0.000 3.3889 0.040 0.123 0.839 0.000 3.4444 0.040 0.125 0.865 0.000 3.5000 0.040 0.128 0.890 0.000 3.5556 0.039 0.130 0.914 0.000 3.6111 0.039 0.132 0.937 0.000 3.6667 0.038 0.134 0.959 0.000 3.7222 0.038 0.136 0.980 0.000 3.7778 0.037 0.138 1.037 0.000 3.8333 0.036 0.140 1.084 0.000 3.8889 0.036 0.142 1.121 0.000 3.9444 0.035 0.144 1.155 0.000 4.0000 0.034 0.146 1.187 0.000 4.0556 0.034 0.148 1.216 0.000 4.1111 0.033 0.150 1.245 0.000 4.1667 0.032 0.152 1.272 0.000 4.2222 0.031 0.154 1.298 0.000 4.2778 0.030 0.156 1.323 0.000 4.3333 0.029 0.157 1.348 0.000 4.3889 0.028 0.159 1.372 0.000 4.4444 0.027 0.160 1.395 0.000 4.5000 0.026 0.162 1.418 0.000 4.5556 0.024 0.163 1.718 0.000 4.6111 0.023 0.165 2.247 0.000 4.6667 0.021 0.166 2.922 0.000 4.7222 0.020 0.167 3.710 0.000 4.7778 0.018 0.168 4.585 0.000 4.8333 0.015 0.169 5.525 0.000 4.8889 0.012 0.170 6.505 0.000 4.9444 0.009 0.170 7.502 0.000 5.0000 0.000 0.171 8.492 0.000 5.0556 0.000 0.000 9.450 0.000 DRAFTTopgolf West Basin Tank Sizing_190424 4/24/2019 5:26:53 PM Page 8 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:2.88 Total Impervious Area:1.76 Mitigated Landuse Totals for POC #1 Total Pervious Area:1.43 Total Impervious Area:3.21 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.869688 5 year 1.195792 10 year 1.432272 25 year 1.755165 50 year 2.013663 100 year 2.287944 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.609309 5 year 0.931075 10 year 1.189443 25 year 1.572702 50 year 1.902899 100 year 2.274401 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 1.287 0.792 1950 1.252 0.800 1951 0.795 0.825 1952 0.528 0.412 1953 0.558 0.411 1954 0.701 0.410 1955 0.752 0.762 1956 0.751 0.548 1957 0.966 0.910 1958 0.659 0.608 DRAFTTopgolf West Basin Tank Sizing_190424 4/24/2019 5:27:25 PM Page 9 1959 0.570 0.408 1960 0.837 0.790 1961 0.791 0.421 1962 0.575 0.369 1963 0.767 0.380 1964 0.689 0.443 1965 1.025 0.406 1966 0.578 0.411 1967 1.265 0.876 1968 1.182 0.539 1969 0.927 0.571 1970 0.804 0.441 1971 0.962 0.430 1972 1.231 0.966 1973 0.505 0.430 1974 0.937 0.393 1975 0.990 0.897 1976 0.722 0.413 1977 0.677 0.391 1978 0.828 0.913 1979 1.009 0.421 1980 1.434 0.839 1981 0.867 0.659 1982 1.450 1.290 1983 0.908 0.850 1984 0.643 0.397 1985 0.879 0.540 1986 0.796 0.854 1987 1.028 0.847 1988 0.568 0.391 1989 0.711 0.364 1990 2.279 1.969 1991 1.632 1.423 1992 0.638 0.564 1993 0.498 0.364 1994 0.474 0.351 1995 0.751 0.519 1996 1.049 0.906 1997 0.922 0.782 1998 0.745 0.423 1999 1.906 1.174 2000 0.874 0.779 2001 0.784 0.397 2002 1.283 1.106 2003 0.998 0.411 2004 1.739 2.173 2005 0.806 0.824 2006 0.751 0.496 2007 2.064 1.363 2008 1.600 1.905 2009 0.985 0.948 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 2.2785 2.1728 2 2.0639 1.9688 3 1.9056 1.9053 DRAFTTopgolf West Basin Tank Sizing_190424 4/24/2019 5:27:25 PM Page 10 4 1.7394 1.4230 5 1.6316 1.3628 6 1.5996 1.2902 7 1.4503 1.1738 8 1.4338 1.1062 9 1.2870 0.9663 10 1.2834 0.9478 11 1.2649 0.9131 12 1.2523 0.9104 13 1.2305 0.9061 14 1.1819 0.8971 15 1.0489 0.8758 16 1.0279 0.8536 17 1.0245 0.8496 18 1.0086 0.8475 19 0.9983 0.8395 20 0.9897 0.8248 21 0.9854 0.8242 22 0.9657 0.8000 23 0.9620 0.7920 24 0.9370 0.7902 25 0.9268 0.7822 26 0.9221 0.7790 27 0.9085 0.7617 28 0.8791 0.6590 29 0.8737 0.6076 30 0.8672 0.5712 31 0.8371 0.5644 32 0.8277 0.5478 33 0.8062 0.5403 34 0.8045 0.5385 35 0.7961 0.5193 36 0.7952 0.4963 37 0.7912 0.4432 38 0.7840 0.4413 39 0.7665 0.4304 40 0.7521 0.4298 41 0.7512 0.4234 42 0.7512 0.4213 43 0.7506 0.4208 44 0.7451 0.4132 45 0.7219 0.4115 46 0.7106 0.4115 47 0.7008 0.4106 48 0.6891 0.4105 49 0.6768 0.4103 50 0.6593 0.4079 51 0.6430 0.4062 52 0.6377 0.3973 53 0.5776 0.3965 54 0.5752 0.3929 55 0.5704 0.3912 56 0.5681 0.3909 57 0.5577 0.3798 58 0.5277 0.3689 59 0.5052 0.3641 60 0.4980 0.3641 61 0.4740 0.3515 DRAFTTopgolf West Basin Tank Sizing_190424 4/24/2019 5:27:25 PM Page 14 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.4181 acre-feet On-line facility target flow:0.3411 cfs. Adjusted for 15 min:0.3411 cfs. Off-line facility target flow:0.2107 cfs. Adjusted for 15 min:0.2107 cfs. DRAFTTopgolf West Basin Tank Sizing_190424 4/24/2019 5:27:48 PM Page 31 Disclaimer Legal Notice This program and accompanying documentation is provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions, Inc. disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions, Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions, Inc. has been advised of the possibility of such damages. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com WWHM2012 PROJECT REPORT DRAFTTopgolf East Basin Vault Sizing_190614 6/14/2019 12:47:33 PM Page 2 General Model Information Project Name:Topgolf East Basin Vault Sizing_190614 Site Name:Topgolf Site Address: City:Renton Report Date:6/14/2019 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.000 Version Date:2018/10/10 Version:4.2.16 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year DRAFTTopgolf East Basin Vault Sizing_190614 6/14/2019 12:47:33 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 8.48 Pervious Total 8.48 Impervious Land Use acre ROADS FLAT 0.56 Impervious Total 0.56 Basin Total 9.04 Element Flows To: Surface Interflow Groundwater DRAFTTopgolf East Basin Vault Sizing_190614 6/14/2019 12:47:33 PM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 0.96 Pervious Total 0.96 Impervious Land Use acre ROADS FLAT 3.7 ROOF TOPS FLAT 4.38 Impervious Total 8.08 Basin Total 9.04 Element Flows To: Surface Interflow Groundwater Vault 1 Vault 1 DRAFTTopgolf East Basin Vault Sizing_190614 6/14/2019 12:47:33 PM Page 6 Mitigated Routing Vault 1 Width:88 ft. Length:148 ft. Depth:5 ft. Discharge Structure Riser Height:4.5 ft. Riser Diameter:18 in. Orifice 1 Diameter:2.2188 in.Elevation:0 ft. Orifice 2 Diameter:5.5625 in.Elevation:2.7 ft. Orifice 3 Diameter:3.4844 in.Elevation:3.9 ft. Element Flows To: Outlet 1 Outlet 2 Vault Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.299 0.000 0.000 0.000 0.0556 0.299 0.016 0.031 0.000 0.1111 0.299 0.033 0.044 0.000 0.1667 0.299 0.049 0.054 0.000 0.2222 0.299 0.066 0.063 0.000 0.2778 0.299 0.083 0.070 0.000 0.3333 0.299 0.099 0.077 0.000 0.3889 0.299 0.116 0.083 0.000 0.4444 0.299 0.132 0.089 0.000 0.5000 0.299 0.149 0.094 0.000 0.5556 0.299 0.166 0.099 0.000 0.6111 0.299 0.182 0.104 0.000 0.6667 0.299 0.199 0.109 0.000 0.7222 0.299 0.215 0.113 0.000 0.7778 0.299 0.232 0.117 0.000 0.8333 0.299 0.249 0.122 0.000 0.8889 0.299 0.265 0.126 0.000 0.9444 0.299 0.282 0.129 0.000 1.0000 0.299 0.299 0.133 0.000 1.0556 0.299 0.315 0.137 0.000 1.1111 0.299 0.332 0.140 0.000 1.1667 0.299 0.348 0.144 0.000 1.2222 0.299 0.365 0.147 0.000 1.2778 0.299 0.382 0.151 0.000 1.3333 0.299 0.398 0.154 0.000 1.3889 0.299 0.415 0.157 0.000 1.4444 0.299 0.431 0.160 0.000 1.5000 0.299 0.448 0.163 0.000 1.5556 0.299 0.465 0.166 0.000 1.6111 0.299 0.481 0.169 0.000 1.6667 0.299 0.498 0.172 0.000 1.7222 0.299 0.514 0.175 0.000 1.7778 0.299 0.531 0.178 0.000 1.8333 0.299 0.548 0.180 0.000 1.8889 0.299 0.564 0.183 0.000 1.9444 0.299 0.581 0.186 0.000 2.0000 0.299 0.598 0.188 0.000 2.0556 0.299 0.614 0.191 0.000 DRAFTTopgolf East Basin Vault Sizing_190614 6/14/2019 12:47:33 PM Page 7 2.1111 0.299 0.631 0.194 0.000 2.1667 0.299 0.647 0.196 0.000 2.2222 0.299 0.664 0.199 0.000 2.2778 0.299 0.681 0.201 0.000 2.3333 0.299 0.697 0.204 0.000 2.3889 0.299 0.714 0.206 0.000 2.4444 0.299 0.730 0.208 0.000 2.5000 0.299 0.747 0.211 0.000 2.5556 0.299 0.764 0.213 0.000 2.6111 0.299 0.780 0.215 0.000 2.6667 0.299 0.797 0.218 0.000 2.7222 0.299 0.813 0.345 0.000 2.7778 0.299 0.830 0.456 0.000 2.8333 0.299 0.847 0.531 0.000 2.8889 0.299 0.863 0.592 0.000 2.9444 0.299 0.880 0.644 0.000 3.0000 0.299 0.897 0.691 0.000 3.0556 0.299 0.913 0.734 0.000 3.1111 0.299 0.930 0.774 0.000 3.1667 0.299 0.946 0.811 0.000 3.2222 0.299 0.963 0.846 0.000 3.2778 0.299 0.980 0.880 0.000 3.3333 0.299 0.996 0.912 0.000 3.3889 0.299 1.013 0.942 0.000 3.4444 0.299 1.029 0.972 0.000 3.5000 0.299 1.046 1.000 0.000 3.5556 0.299 1.063 1.028 0.000 3.6111 0.299 1.079 1.055 0.000 3.6667 0.299 1.096 1.081 0.000 3.7222 0.299 1.112 1.106 0.000 3.7778 0.299 1.129 1.131 0.000 3.8333 0.299 1.146 1.155 0.000 3.8889 0.299 1.162 1.179 0.000 3.9444 0.299 1.179 1.271 0.000 4.0000 0.299 1.196 1.328 0.000 4.0556 0.299 1.212 1.376 0.000 4.1111 0.299 1.229 1.419 0.000 4.1667 0.299 1.245 1.459 0.000 4.2222 0.299 1.262 1.497 0.000 4.2778 0.299 1.279 1.533 0.000 4.3333 0.299 1.295 1.568 0.000 4.3889 0.299 1.312 1.601 0.000 4.4444 0.299 1.328 1.633 0.000 4.5000 0.299 1.345 1.665 0.000 4.5556 0.299 1.362 1.903 0.000 4.6111 0.299 1.378 2.313 0.000 4.6667 0.299 1.395 2.828 0.000 4.7222 0.299 1.411 3.420 0.000 4.7778 0.299 1.428 4.059 0.000 4.8333 0.299 1.445 4.720 0.000 4.8889 0.299 1.461 5.375 0.000 4.9444 0.299 1.478 5.995 0.000 5.0000 0.299 1.494 6.556 0.000 5.0556 0.299 1.511 7.040 0.000 5.1111 0.000 0.000 7.436 0.000 DRAFTTopgolf East Basin Vault Sizing_190614 6/14/2019 12:47:33 PM Page 8 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:8.48 Total Impervious Area:0.56 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.96 Total Impervious Area:8.08 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.862072 5 year 1.44225 10 year 1.898266 25 year 2.55556 50 year 3.104167 100 year 3.703562 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.833024 5 year 1.422513 10 year 1.881635 25 year 2.535597 50 year 3.074432 100 year 3.656273 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 1.648 0.735 1950 1.791 0.960 1951 0.916 1.326 1952 0.439 0.216 1953 0.335 0.719 1954 0.630 0.653 1955 0.666 1.105 1956 0.793 0.915 1957 1.030 1.003 1958 0.532 0.823 DRAFTTopgolf East Basin Vault Sizing_190614 6/14/2019 12:48:06 PM Page 9 1959 0.459 0.850 1960 1.000 1.147 1961 0.780 0.765 1962 0.344 0.204 1963 0.757 0.777 1964 0.730 0.659 1965 1.148 0.795 1966 0.480 0.503 1967 1.817 1.046 1968 1.032 0.639 1969 1.027 0.693 1970 0.727 0.576 1971 1.060 0.893 1972 1.602 1.038 1973 0.381 0.756 1974 0.973 0.685 1975 1.101 1.052 1976 0.742 0.711 1977 0.654 0.597 1978 0.739 0.627 1979 0.460 0.207 1980 1.971 1.153 1981 0.712 0.515 1982 1.798 1.535 1983 0.882 0.858 1984 0.560 0.252 1985 0.751 0.738 1986 0.884 1.397 1987 0.851 1.538 1988 0.327 0.501 1989 0.273 0.476 1990 3.569 3.373 1991 2.295 1.926 1992 0.638 0.636 1993 0.381 0.674 1994 0.274 0.197 1995 0.581 0.940 1996 1.542 1.501 1997 1.027 1.479 1998 0.771 0.820 1999 2.583 1.124 2000 0.831 0.772 2001 0.394 0.299 2002 1.546 1.444 2003 1.205 0.575 2004 1.868 3.929 2005 0.878 0.946 2006 0.890 0.923 2007 3.303 3.247 2008 2.245 3.280 2009 1.200 1.438 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 3.5685 3.9294 2 3.3033 3.3727 3 2.5827 3.2797 DRAFTTopgolf East Basin Vault Sizing_190614 6/14/2019 12:48:06 PM Page 10 4 2.2954 3.2468 5 2.2449 1.9255 6 1.9705 1.5378 7 1.8680 1.5355 8 1.8169 1.5006 9 1.7980 1.4792 10 1.7909 1.4444 11 1.6485 1.4380 12 1.6018 1.3974 13 1.5462 1.3260 14 1.5423 1.1534 15 1.2047 1.1474 16 1.1995 1.1235 17 1.1483 1.1054 18 1.1011 1.0525 19 1.0603 1.0457 20 1.0321 1.0383 21 1.0298 1.0033 22 1.0275 0.9600 23 1.0274 0.9456 24 1.0000 0.9402 25 0.9727 0.9234 26 0.9156 0.9152 27 0.8902 0.8934 28 0.8842 0.8578 29 0.8822 0.8500 30 0.8776 0.8230 31 0.8515 0.8200 32 0.8306 0.7952 33 0.7932 0.7768 34 0.7802 0.7718 35 0.7707 0.7654 36 0.7572 0.7557 37 0.7509 0.7379 38 0.7419 0.7350 39 0.7391 0.7186 40 0.7304 0.7111 41 0.7270 0.6926 42 0.7118 0.6852 43 0.6656 0.6736 44 0.6543 0.6586 45 0.6376 0.6531 46 0.6304 0.6393 47 0.5807 0.6361 48 0.5599 0.6272 49 0.5317 0.5968 50 0.4797 0.5756 51 0.4604 0.5751 52 0.4594 0.5147 53 0.4385 0.5028 54 0.3944 0.5012 55 0.3813 0.4757 56 0.3805 0.2991 57 0.3436 0.2525 58 0.3348 0.2157 59 0.3271 0.2067 60 0.2735 0.2035 61 0.2727 0.1972 DRAFTTopgolf East Basin Vault Sizing_190614 6/14/2019 12:48:06 PM Page 14 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.5124 acre-feet On-line facility target flow:0.2149 cfs. Adjusted for 15 min:0.2149 cfs. Off-line facility target flow:0.1554 cfs. Adjusted for 15 min:0.1554 cfs. DRAFTTopgolf East Basin Vault Sizing_190614 6/14/2019 12:48:29 PM Page 31 Disclaimer Legal Notice This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2019; All Rights Reserved. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com