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HomeMy WebLinkAboutRS_Geotechnical_Report_190626_v1June 20, 2019 ES -6757 Valley Tower Associates, LLC 15029 Woodinville -Redmond Road, Suite 200 Woodinville, Washington 98072 Attention: Mr. Joe Carlson Subject: Geotechnical Supplement Proposed Expansion Chateau Valley Tower 4320 Davis Avenue South Renton, Washington 98055 Reference: Earth Consultants, Inc. Geotechnical Engineering Study E-9511, dated January 16, 2002 Dear Mr. Carlson: Earth Solutions NW «C Earth Solutions NW I_I_c Geotechnical Engineering, Construction Observation/Testing and Environmental Services As requested, Earth Solutions NW, LLC (ESNW) has prepared this letter and geotechnical supplement to the previously prepared geotechnical report. It should be noted that Earth Consultants, Inc. and the undersigned previously prepared the above referenced report for the site. We understand an expansion to the north of the existing assisted living facility is planned. Based on our understanding of current plans, the expansion will incorporate construction of a parking structure and related excavation and grading activities. Based on review of the previous geotechnical report prepared for the overall site area, construction as proposed is feasible from a geotechnical standpoint. We understand the lower parking level subgrade for the garage will be roughly elevation 95 feet. Soils are identified as pre-vashon drift (Qu) comprised of glacial till and associated sand, gravel and silts. In general, competent native soils consistent with pre- vashon drift were encountered throughout subgrade areas associated with the earlier phase of construction. As such, similar suitable site geologic conditions are expected to be encountered during the proposed expansion and related earthwork activities. With respect to groundwater, localized and discrete seepage zones typical of drift deposits should be expected. In any case, we do not expect extensive dewatering efforts will be necessary as part of the proposed garage level excavations. It should also be noted that during deep excavations for the vault structure constructed as part of the earlier phase, no groundwater related issues were encountered. Given the similarity in excavation depth relative to the planned garage structure, we do not foresee significant groundwater related challenges. However, the geotechnical engineer should be onsite during excavation activities to confirm conditions, and provide supplement recommendations as deemed necessary. 1805 - 136th Place N.E., Suite 201 0 Bellevue, WA 98005 0 (425) 449-4704 • FAX (425) 449-4711 Valley Tower Associates, LLC June 20, 2019 ES -6757 Page 2 We trust this letter and geotechnical supplement meet your current needs. If you have questions, or if additional information is required, please call. Sincerely, EARTH SOLUTIONS NW, LLC Raymond A. Coglas, P.E. Principal Engineer Earth Solutions NW. LLC GEOTECHNICAL ENGINEERING STUDY CHATEAU VALLEY CENTER SOUTH 45T" STREET AND DAVIS AVENUE SOUTH RENTON, WASHINGTON E-9511 January 16, 2002 PREPARED FOR DAVIS AVENUE ASSOCIATES, LLC A EXPIRES 71 Raymond A. Coglas, P.E. Project Manager Earth Consultants, Inc. 1805 - 136th Place Northeast, Suite 201 Bellevue, Washington 98005 (206) 643-3780 Toll Free 1-888-739-6670 January 16, 2002 Davis Avenue Associates, LLC PO Box 907 Woodinville, Washington 98072 Attention: Mr. Darrell Johnson Dear Mr. Johnson: Earth Consultants Inc. Geotechnical Engineers, Geologists & Environmental Scientists E-951 1 We are pleased to submit this geotechnical engineering study for the proposed Chateau Valley Center to be located at South 45th Street and Davis Avenue South, Renton, Washington. This study presents the results of our field exploration, and engineering analyses. The scope of our services for producing this study was outlined in our proposal PR -9511, dated October 11, 2001. Based on the results of our study, it is our opinion development of the site as planned is feasible from a geotechnical standpoint. The proposed retirement facility and parking garage will be constructed throughout the central and east portions of the property. The proposed finish floor elevation of the garage level will be approximately elevation 103 feet. Based on the existing ground surface elevation along the east margins of the property, excavations of approximately eight (8) to twelve (12) feet will likely be necessary to establish the building subgrade elevation. Temporary slopes or a combination of shoring and temporary slopes will be necessary to construct portions of the building excavation. Silty sand and sandy silt soils were generally observed at the test pit locations. The soils were generally in a loose to medium dense condition throughout the upper ten (10) feet of the excavations. At the time the test pits were excavated (October, 2001) the soils encountered were generally in a wet condition. In our opinion, the proposed retirement facility can be supported on conventional spread and continuous footings bearing on competent native soils or structural fill. Recommendations regarding foundations, excavation support, and other geotechnical issues are presented in this geotechnical engineering study. 1805 -136th Place N.E., Suite 201, Bellevue, Washington 98005 Bellevue (425) 643-3780 FAX (425) 746-0860 Toll Free (888) 739-6670 Davis Avenue Associates, LLC January 16, 2002 E-951 1 We appreciate opportunity to provide our services during the design phase of this project. If you have questions about the content of this report, or if we can be of further assistance, please call. Sincerely, EARTH CONSULTANTS, INC. Raymond A. Coglas, P.E. Project Manager RAC/jme Earth Consultants, Inc. TABLE OF CONTENTS E-9511 PAGE INTRODUCTION..............................,,.................................................................. 1 General........................................................................................................... 1 ProjectDescription.......................................................................................... 1 SITECONDITIONS................................................................................................ 2 Surface........................................................................................................... 2 Subsurface...................................................................................................... 2 Groundwater................................................................................................. 3 LaboratoryTesting.......................................................................................... 3 DISCUSSION AND RECOMMENDATIONS................................................................ 4 General........................................................................................................... 4 Site Preparation and General Earthwork.............................................................. 5 ShoringSystem............................................................................................... 6 CantileveredShoring..................................................................................... 7 SoldierPiles................................................................................................. 8 Lagging....................................................................................................... 8 ShoringMonitoring...................................................................................... 9 Foundations..................................................................................................... 10 Permanent Retaining and Foundation Walls......................................................... 11 Seismic Design Considerations........................................................................... 12 Slab -on -Grade Floors....................................................................................... 13 SiteDrainage.........................................................,......................................... 13 Excavations and Slopes................................................................................... 13 Utility Trench Backfill........................................................................................ 14 PavementAreas............................................................................................... 15 LIMITATIONS....................................................................................................... 16 AdditionalServices........................................................................................... 16 Earth Consultants, Inc. TABLE OF CONTENTS E-9511 APPENDICES Appendix A Field Exploration Appendix B Laboratory Test Results ILLUSTRATIONS Plate 1 Vicinity Map Plate 2 Test Pit Location Plan Plate 3 Temporary Cantilever Soldier Pile Wall Plate 4 Retaining Wall Drainage and Backfill Plate 5 Shoring Wall Drainage Plate 6 Typical Footing Subdrain Detail Plate 7 Typical Utility Trench Fill Plate A 1 Legend Plates A2 through A10 Test Pit Logs Plates 131 and B2 Grain Size Analyses Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY PROPOSED CHATEAU VALLEY CENTER SOUTH 45TH STREET AND DAVIS AVENUE SOUTH RENTON, WASHINGTON E-9511 INTRODUCTION General This geotechnical study presents the results of our field exploration and engineering analyses for the proposed Chateau Valley Center facility to be located at South 45th Street and Davis Avenue South, Renton, Washington. The proposed development, subsurface conditions, and the site were evaluated for the purpose of formulating geotechnical recommendations. The general location of the site is shown on the Vicinity Map, Plate 1. The approximate site boundaries and location of the proposed facility are illustrated on the Test Pit Location Plan (Plate 2). Project Description We understand construction of a 179 unit retirement facility is planned for the site. A parking garage will occupy the lower level of one wing of the complex. One level of below grade construction will be necessary to construct the parking level. The finish floor elevation of the parking garage will be approximately elevation 103 feet. Based on the existing ground surface elevation along the east margins of the property, excavations of approximately eight (8) to twelve (12) feet will likely be necessary to establish the building subgrade elevation. Temporary slopes or a combination of shoring and temporary slopes will likely be necessary to construct the eastern portions of the building excavation. Based on our understanding of the proposed site development, grading of the building and pavement areas will primarily require cuts. The majority of the cuts will be necessary along the east margins of the property, and throughout the footprint of the parking garage. We understand the amount of fill necessary to raise existing site grades will be minimal, and will occur primarily throughout the pavement areas in the northern portions of the site. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 16, 2002 E-951 1 Page 2 We understand the building construction will consist of post -tensioned slabs throughout the proposed garage, and relatively lightweight wood frame construction throughout the remainder of the facility. At the time this geotechnical study was prepared, specific loading criteria were not available. However, based on our experience with similar developments, we estimate column loads will be in the range of 200 to 400 kips. We estimate wall loads will range between 2 to 4 kips per lineal foot, and slab -on -grade loading of approximately 150 pounds per square foot (psf). If the above design criteria are incorrect or change, we should be consulted to review the recommendations contained in this report. In any case, ECI should be retained to perform a general review of the final design. SITE CONDITIONS Swfar_p The subject property is 2.77 acres and is currently undeveloped. The approximate outline of the property and adjacent roadways are illustrated on the Test Pit Location Plan (Plate 2). The site is heavily vegetated with deciduous trees and a variety of groundcover species. The site topography generally slopes downward to the north and west. The overall vertical relief across the site from the southeast to the northwest is approximately twenty-two (22) feet. The topographic survey completed by Touma Engineers indicates the presence of a storm drain that may discharge onto the site near the southeast corner of the property. At the time the test pits were excavated (October, 2001) areas of surface water that may be associated with the storm drain were observed. Throughout the northwest portion of the property, an existing drainage ditch appears to be collecting surface water runoff and directing the water to a storm drain that enters the property along Davis Avenue South. Suhsurfar_p Subsurface conditions were assessed by excavating nine (9) test pits to a maximum depth of twelve (12) feet below the existing site grade. The approximate test pit locations are illustrated on the Test Pit Location Plan (Plate 2). Please refer to the test pit logs (Plates A2 through A10) for a more detailed description of the subsurface conditions observed. The following is a generalized description of the subsurface conditions encountered. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 16, 2002 E-9511 Page 3 Loose to medium dense silty sand and sandy silt soils (Unified Soil Classification ML) were primarily observed at the test pit locations. The geologic map of King County indicates the site is located on the margins of the alluvial deposits characteristic of the Kent Valley. Pre-Vashon drift (Qu) undifferentiated, is identified on the map in the vicinity of the subject property. Lacustrine sand, silt, and clay, as well as glacial till can be encountered throughout this deposit. The King County Soil Conservation Survey (SCS) classifies the site and surrounding areas to the east as gravelly sandy loam (Agc), or glacial till. Immediately to the west of the property, the SCS indicates the presence of urban land (Ur) which is associated with areas of land disturbance due to cuts and fills. Based on the soil conditions observed and the geologic and SCS map classifications, Hydrologic Soil Group C should be used for the site drainage design. At the time of the test pit excavations (October, 2001) the native silty sand and sandy silt soils were in a wet condition. In our opinion, due to the wet and moisture sensitive nature of the soils, use of the soil as structural fill will be difficult. A summer construction schedule, in our opinion, may help improve the feasibility of successfully using the native soils as structural fill. Groundwater Groundwater seepage was observed at several test pit locations at depths of approximately two (2) feet to seven (7) feet at the time of our subsurface exploration (October 2001). Control of groundwater seepage will likely be necessary during the excavation phase of the planned development. Groundwater seepage levels and the rate of seepage are not static; fluctuations in the level and rates can be expected depending on the season, amount of rainfall, surface water runoff, and other factors. Generally, the level and rate of seepage is higher in the wetter winter months (typically October through May). Laboratory Testing The results of laboratory tests performed on specific samples are provided in Appendix B, or at the appropriate sample depth on the test pit logs (Plates A2 through A10). It is important to note that these test results may not accurately represent the overall in-situ soil conditions. Our geotechnical recommendations are based on our interpretation of these test results and their use in guiding our engineering judgement. ECI cannot be responsible for the interpretation of these data by others. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC E-951 1 January 17, 2002 Page 4 DISCUSSION AND RECOMMENDATIONS General Based on the subsurface conditions observed at the test pit locations and our understanding of the proposed development, it is our opinion construction of the new retirement facility is feasible from a geotechnical standpoint. The primary geotechnical considerations are associated with foundations support, site drainage, and excavation shoring. Throughout the proposed building footprint, loose to medium dense sandy silt and silty sand soils were observed at the test pit locations. Due to the variability in soil conditions and soil density observed at the test pit locations, it is our opinion the proposed retirement facility should be supported on conventional spread and continuous footings bearing on competent native soils or structural fill. Cuts of approximately eight (8) to twelve (12) feet below existing site grades will be necessary to establish the finish floor elevation for the proposed parking garage. The finish floor elevation for the proposed parking garage will be approximately elevation 103 feet. The construction of temporary slopes, or a combination of temporary slopes and cantilever shoring will be necessary to complete the excavation. Based on the proposed building footprint, the use of cantilever shoring will likely be necessary to support the parking garage excavation along the east property line. The use of temporary slopes can be considered throughout other areas of the building excavation that are not in close proximity to the property line. The extent of cantilever shoring necessary to support the proposed building excavation should be determined once the final finish floor elevations and building footprint are established. Design recommendations for cantilever shoring are presented in the "Cantilever Shoring" section of this report. Surface water runoff entering the site from the east will need to be intercepted and directed around the building site. We understand the project civil engineer has assessed the influence of offsite surface water runoff entering the site. We understand the drainage plan will provide drains along the perimeter of the site, as necessary, to address offsite surface water runoff. The installation of perimeter footing and foundation drains will be necessary to intercept groundwater around the building foundation. Drainage recommendations are provided in the "Permanent Retaining and Foundation Walls" and "Site Drainage" sections of this report. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 E-951 1 Page 5 This geotechnical study has been prepared for the exclusive use of Davis Avenue Associates, LLC, and their representatives. This study was prepared for specific application to this project only, and in a manner consistent with that level of care and skill ordinarily exercised by other members of the geotechnical profession currently practicing under similar conditions in this area. No other warranty, expressed or implied, is made. We recommend that this geotechnical study, in its entirety, be included in the project contract documents for the information of the contractor. Site Preparation and General Earthwork The proposed building and pavement areas should be stripped of vegetation and deleterious materials. The ground surface where structural fill or foundations will be placed should be observed by a representative of ECI. Excavation depths of up to approximately eight (8) to twelve (12) feet below existing grades will be necessary to construct the parking garage and adjacent building areas. A combination of temporary slopes and cantilever shoring will be necessary to construct the excavation. Temporary slopes used to construct the excavation should be covered with plastic sheeting to reduce the potential for soil erosion. Groundwater seepage encountered in the excavation should not be allowed to collect in the excavation. Where groundwater seepage is encountered along the temporary slope face, two-inch crushed rock can be used to help reduce soil piping along the slope, if necessary. An ECI representative should observe the excavation and temporary slopes to verify soil and groundwater conditions. Based on the subsurface conditions observed at the test pit locations, medium dense sandy silt and silty sand will likely be encountered at the building subgrade elevations. Due to the moisture sensitive nature of the native soils, measures to reduce soil disturbance along the building subgrade may be necessary if the construction is performed during the wet season. Two-inch crushed rock or larger two-inch to four -inch quarry spalls can be placed along the building subgrade to help reduce construction related disturbances to the native soils. The building foundations should be supported on competent native soils or structural fill. If loose or unstable soils are encountered in the foundation areas, overexcavation and replacement with structural fill may be necessary. The foundation subgrade for the proposed building foundations should be observed by a representative of ECI to verify soil conditions. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 E-951 1 Page 6 Structural fill is defined as compacted fill placed under foundations or other load-bearing areas. Structural fill beneath foundations should be placed in horizontal lifts not exceeding twelve (12) inches in loose thickness and compacted to a minimum of ninety (90) percent of its laboratory maximum dry density. The maximum dry density should be determined in accordance with ASTM Test Designation D-1557-91 (Modified Proctor). The fill materials should be placed at or near the optimum moisture content. The native sandy silt and silty sand soils were generally in a wet condition at the time of our exploration. In our opinion, the native sandy silt and silty sand soils will not likely be suitable for use as structural fill in foundation areas. Structural fill used in foundation areas should be a granular material with a moisture content that is at or near the optimum moisture content. During wet weather conditions, structural fill used in foundation areas should consist of a well graded granular soil with less than five percent fines (percent passing the #200 sieve, based on the minus % inch fraction). Samples of fill soils intended for use in foundation areas should be submitted to ECI for laboratory testing and approval. Shoring System The use of temporary shoring will likely be necessary along portions of the east building excavation. Due to the proposed excavation depths, conventional cantilevered shoring consisting of soldier piles and lagging can be considered for temporary support of the excavation. In our opinion, due to the generally loose condition of the existing fill and native soil that will be encountered in the building excavation, soil nailing of the excavation will be difficult to accomplish successfully. The potential for groundwater seepage and water bearing sands along the lower portions of the excavation will also create difficult soil nailing conditions. If desired, the feasibility of soil nailing can be assessed further, if requested. To reduce the height of the shoring, temporary slopes can be constructed above the shoring wall in areas where there is available space, or where granted. For preliminary design purposes, temporary slopes shoring can be inclined at 1.5H:1 V (Horizontal: Vertical). Earth Consultants, Inc. easements have been constructed above the GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 Cantilevered Shoring E-951 1 Page 7 Temporary slopes constructed above the proposed temporary shoring will impart higher lateral earth pressures on the shoring. An active earth pressure imposed by an equivalent fluid with a unit weight of forty-five (45) pcf can be used for shoring where slopes inclined at 1.5H:1 V are present above the shoring. Where horizontal backfill conditions are present, an equivalent fluid with a unit weight of thirty-five (35) pounds per cubic foot (pcf) can be used. These lateral earth pressure value assume no surcharges, and no hydrostatic pressure. Where applicable, surcharge loading from adjacent structures, vehicles, or any other load source should be included in the shoring design. Surcharge loading from adjacent roadways or buildings should be considered if the load source is within a horizontal distance equal to the excavation depth. To account for traffic surcharge loads, seventy (70) pounds per square foot (psf) should be applied in a rectangular distribution along the height of the shoring wall, where applicable. ECI can provide modified equivalent fluid pressures to account for sloping conditions above the shoring that are different from those described above. Passive pressure acting along the embedded portion of the soldier piles may be used to resist active earth pressures and surcharge loading. The passive earth pressure may be calculated using an equivalent fluid with a unit weight of three hundred (300) pcf. The upper two feet of the embedded portion of the soldier pile should be neglected when calculating passive resistance. The passive resistance can be applied to two times the diameter of the soldier piles. Mobilization of full passive pressure assumes that the excavation bottom is horizontal for at least four times the depth of the soldier pile embedment. ECI should be contacted to provide appropriate design values if sloping conditions are present along the excavation bottom. A typical pressure distribution for a temporary cantilever wall design is shown on Plate 3. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 Soldier Piles E-951 1 Page 8 The cantilever soldier piles must penetrate far enough below the bottom of the excavation to prevent wall movement. As mentioned previously, passive resistance along the embedded portion of the pile can be calculated using an equivalent fluid of three hundred (300) pcf. The allowable axial capacity of the soldier piles in compression can be developed from a combination of end bearing at the tip of the pile and skin friction along the shaft of the pile. For design purposes, we recommend using an allowable end bearing of 10 kips per square foot (ksf) for piles penetrating at least ten (10) feet below the excavation level. Resistance along the embedded portion of the pile shaft can be calculated using a unit skin friction value of 0.75 ksf for piles penetrating at least ten (10) below the excavation level. Above the excavation level, frictional resistance along the soldier pile should be neglected. The piling contractor should be prepared to case the soldier pile excavations if groundwater seepage and caving of the excavation are encountered. The success of open hole excavations without casing should be verified at the beginning of construction. The bottom of the soldier pile excavations should be free of loose soil prior to placing the structural concrete or lean mix. If an excessive amount of groundwater is encountered at the bottom of the holes, the concrete should be tremied into the holes. Lagging The effects of soil arching between the soldier piles allows the lagging for the temporary shoring to be designed with a reduced value of lateral earth pressure. For soldier piles with a center to center spacing of at least three pile diameters, a 50 percent reduction of the lateral earth pressures can be used for the design of lagging. Lagging installed between the soldier piles is used to support the sides of the excavation, and helps prevent subsidence at the ground surface around the excavation. When the excavation begins, installation of the lagging should begin immediately to help reduce sloughing of the excavation. The contractor should be prepared to address the potential for sloughing of the excavation during the lagging operation. Groundwater seepage may also contribute to sloughing. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 E-9511 Page 9 The void space between the excavation and the back of the lagging should be backfilled with a free -draining material. The shoring wall should be backfilled as soon as possible after installation of the lagging to help reduce subsidence and lateral movement of the excavation. The backfill should not prevent or impede the passage of groundwater. Where localized areas of sloughing and the creation of voids develop, the use of lean mix injected through the lagging and into the void area can be considered. Shoring Monitoring Whenever excavations are made adjacent to existing streets, utilities and structures, there exists the potential for excavation related ground movements. A monitoring program should include the surveying of adjacent streets and structures for purposes of detecting any horizontal or vertical movements related to the excavation. We recommend the establishment of a monitoring program such that excessive movements are detected early, to allow for remedial actions to be taken to prevent serious damage to adjacent facilities and structures. Prior to beginning the proposed excavation, we recommend performing a detailed photo and videotape survey of the adjacent pavement areas and structures. Periodic monitoring of these areas should be performed throughout the duration of construction. Survey points should be established along the temporary shoring wall to monitor horizontal and vertical movements during the excavation phase of construction. The survey points should be established and monitored by a licensed surveyor. ECI should meet with the contractor and surveyor prior to the installation of the shoring to discuss the location of the monitoring points, and to establish a program for acquiring the readings. All readings should be reviewed by an engineer from our office. We estimate lateral movements at the top of the soldier piles should not exceed one inch. However, movements in excess of one inch may occur as a result of construction related disturbances or unforeseen site conditions. Piles with movements in excess of one inch should be evaluated by ECI. If necessary, remedial measures will be recommended. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 Fnundatinns E-951 1 Page 10 Throughout the proposed building footprint, loose to medium dense sandy silt and silty sand soils were observed at the test pit locations. Due to the variability in soil conditions and soil density observed at the test pit locations, it is our opinion the proposed retirement facility should be supported on competent native soils or structural fill. Loose or unstable soils encountered at the footing subgrade should be overexcavated and replaced with a granular structural fill. The width of the overexcavation below the footings should extend a minimum of twelve (12) inches beyond the edges of the foundation. An ECI representative should observe the foundation subgrade and the placement and compaction of structural fill soils in the foundation areas. Provided the foundations are supported on competent native soils or structural fill, an allowable soil bearing capacity of three thousand (3,000) psf can be used for design of the footings. Continuous and individual spread footings should have minimum widths of eighteen (18) and twenty-four (24) inches, respectively. Loading of this magnitude would be provided with a theoretical factor -of -safety in excess of three against actual shear failure, provided the foundations are placed on at least two feet of structural fill. A one- third increase in the above allowable soil bearing capacity can be assumed for short-term seismic loading conditions. Provided the foundations are installed in accordance with the recommendations contained in this report, we estimate total foundation settlements of approximately one inch and differential settlement of approximately one half inch. Most of the anticipated settlements should occur during construction as dead loads are applied. Lateral loads can be resisted by friction between the base of the foundation and the supporting soil, and by passive soil pressure acting on the face of the buried portion of the foundation. Resistance to lateral loads from passive earth pressures can be calculated using an equivalent fluid pressure of three hundred fifty (350) pcf. To achieve adequate passive resistance, the foundations must be backfilled with a granular structural fill. For frictional capacity, a coefficient of 0.40 can be used for foundations bearing on granular structural fill. These lateral resistance values are allowable values; a factor -of - safety of 1.5 has been included. The footing excavations should be observed by a representative of ECI to assess soil conditions and the need for overexcavation. Density testing of the structural fill placed in foundation areas should also be performed periodically by ECI. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 Permanent Retaininq and Foundation Walls E-951 1 Page 11 The foundation walls for the proposed facility should be designed to resist lateral earth pressures from the retained soils, and any surcharge loading. For a restrained foundation wall condition, an equivalent fluid of fifty (50) pcf can be used to calculate the lateral earth pressures on the foundation walls. For unrestrained cantilever retaining wall conditions, an equivalent fluid of thirty-five (35) pcf can be used for calculating earth pressures. Lateral earth pressures calculated using the above equivalent fluid values assume drainage will be provided around the walls such that hydrostatic pressures cannot develop. If sloping backfill conditions are present behind the walls, ECI should review the slope configuration and provide supplement recommendations for surcharge loading, if applicable. For traffic surcharge loading, seventy (70) psf should be applied in a rectangular distribution along the height of the wall, where applicable. The walls should be provided with a perforated drain pipe and backfilled with a free - draining material. The free -draining material should extend at least eighteen (18) inches behind the wall. The remainder of the backfill should consist of granular structural fill. A typical wall backfill and drainage detail for the foundation walls is illustrated on Plates 4. In areas where the permanent foundation wall will be constructed along the temporary shoring, sheet drain material such as Mira -Drain 6000 should be attached to the lagging of the temporary shoring. Two-inch diameter weep holes spaced approximately every six feet should be installed at the base of the wall. The weep holes should be connected to a collector pipe installed along the inside perimeter of the foundation. A typical sheet drain and collector pipe detail is illustrated on Plate 5. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 Seismic Design Considerations E-951 1 Page 12 The Puget Sound region is classified as Zone 3 by the Uniform Building Code (UBC). The largest earthquakes in the Puget Sound region have been subcrustal (intraplate) events, ranging in depth from fifty (50) to seventy (70) kilometers. Such deep events have exhibited no surface faulting. Weaver and Shedlock (1989) researched the probable or known source areas for the crustal, intraplate, and subduction zone earthquakes in the Washington and Oregon area. Crustal and intraplate earthquakes are the only events in Washington and Oregon in which there is a historical record. Shallow crustal earthquakes occur within the North American Plate, and typically do not exceed focal depths of approximately 20 kilometers. Intraplate earthquakes occur in the subducting Juan de Fuca plate, and typically occur below depths of 40 kilometers. The recent February 28, 2001 earthquake that was focused just north of Olympia, Washington was an intraplate earthquake, and had a magnitude of ML =6.8. The subduction zone earthquake, in which there is no historical record in the Washington and Oregon area, would have its source along the interface between the North American Plate and the subducting Juan de Fuca Plate. Magnitude 8+ earthquakes are thought to be possible along this interface, and would occur at depths of approximately 50 to 60 kilometers (Weaver and Shedlock, 1989). The UBC Earthquake regulations have established a series of soil profile types that are used as a basis for seismic design of structures. Based on the encountered soil conditions, it is our opinion that soil type So from Table 16-J of the 1997 UBC should be used for design. Liquefaction is a phenomenon in which soils lose all shear strength for short periods of time during an earthquake. The effects of liquefaction may be large total and/or differential settlement for structures with foundations founded in the liquefying soils. Groundshaking of sufficient duration results in the loss of grain -to -grain contact and rapid increase in pore water pressure, causing the soil to behave as a fluid for short periods of time. To have potential for liquefaction, a soil must be cohesionless with a grain size distribution of a specified range (generally sands and silt); it must be loose to medium - dense; it must be below the groundwater table; and it must be subject to sufficient magnitude and duration of groundshaking. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 E-951 1 Page 13 Based on the soil and groundwater conditions observed at the site, it is our opinion that the site has a low susceptibility to liquefaction. The medium dense to dense condition of the native soils is the primary basis for this conclusion. Slab -on -Grade Floors Slab -on -grade floors for the proposed facility should be supported on competent native soils or structural fill. Loose or unstable subgrade soils should be compacted or replaced with structural fill. A minimum four inch capillary break consisting of free draining sand or gravel with a fines content of less than 5 percent should be placed below the slab. A vapor barrier consisting of 6 -mil plastic sheeting should also be placed below the slab to help reduce the buildup of water vapor below the slab. The subgrade soils in the slab -on - grade areas should be observed by a representative of ECI prior to constructing the slab. Site Drainage Installation of a perimeter foundation drain around the foundation walls for the proposed facility is recommended. Plates 4 and 5 illustrate a typical perimeter drain at the foundation walls. Plate 6 provides a typical perimeter drain detail for a shallow footing. Groundwater collected in the perimeter foundation drain system should be directed to a tightline drain system. The roof drain system should not be connected to the perimeter drain system. The presence of groundwater seepage should be expected along the face of the proposed temporary slopes for the building excavation. Greater amounts of seepage should be expected if the construction is performed during the winter and early spring. In our opinion, the impact of groundwater seepage during construction will be minimal if the construction is performed during the summer months. An ECI representative should be on-site during the excavation phase of construction to assess groundwater conditions. If excessive groundwater conditions are encountered, the use of sumps may be necessary to collect and discharge groundwater seepage from the excavation. Excavations and Slop The following information is provided solely as a service to our client. Under no circumstances should this information be interpreted to mean that ECI is assuming responsibility for construction site safety or the contractor's activities; such responsibility is not being implied and should not be inferred. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 E-951 1 Page 14 In no case should excavation slopes be greater than the limits specified in local, state, and Federal safety regulations. Based on the information obtained from our field exploration, the soils observed would be classified as Type C soils by OSHA. As such, temporary cuts in these soils should be sloped at an inclination no steeper than 1.5H:1 V (Horizontal: Vertical). ECI should observe the excavations to assess soil and groundwater conditions, and verify the OSHA soil type. As previously discussed, groundwater seepage present along temporary slopes may cause piping and erosion of the slopes. Two-inch crushed rock can be placed in these areas to control piping and slope erosion, if necessary. Temporary slopes should be protected with plastic sheeting. Permanent cut and fill slopes should be inclined no steeper than 2H:1 V. Cut slopes should be observed by ECI during excavation to verify that conditions are as anticipated. Supplementary recommendations can then be developed, if needed, to improve stability, including flattening of slopes or installation of surface or subsurface drains. In any case, water should not be allowed to flow uncontrolled over the top of slopes. Permanently exposed slopes should be seeded with an appropriate species of vegetation to reduce erosion and improve stability of the surficial layer of soil. Utility Trench Backfill Based on the soil conditions encountered at the time of our exploration, the native soils should provide adequate support for utilities. If remedial measures are necessary to provide adequate support for utilities, the unsuitable soils can be overexcavated and replaced with a rock ballast and pipe bedding material such as pea gravel. Utility trench backfill is a primary concern in reducing the potential for settlement in pavement areas. It is important that the utilities be adequately supported in the bedding material. The material should be hand tamped to ensure support is provided around the haunches of these structures. Fill should be carefully placed and tamped to about twelve (12) inches above the crown of the pipe before heavy compaction equipment is brought into use. The remainder of the backfill should be placed in lifts having a loose thickness of less than twelve (12) inches. A typical trench backfill section and compaction requirements for load supporting and non -load supporting areas is presented on Plate 7. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC January 17, 2002 Pavement Areas E-9511 Page 15 The adequacy of site pavements is related in part to the condition of the underlying subgrade. ECI should observe proofrolling of the pavement subgrade prior to constructing the pavement section. The top twelve (12) inches of the subgrade should be compacted to 95 percent of the maximum dry density (per ASTM D-1557-91). It is possible that some localized areas of soft, wet or unstable subgrade may still exist after this process. Therefore, overexcavation and a greater thickness of structural fill or crushed rock may be needed to stabilize these localized areas. For preliminary design, the following pavement section for lightly -loaded areas can be used: Two inches of asphalt concrete (AC) over four inches of crushed rock base (CRB) material, or • Two inches of AC over three inches of asphalt treated base (ATB) material. Heavier truck -traffic areas will require thicker sections depending upon site usage, pavement life and site traffic. As a general rule, the following sections can be considered for truck -trafficked areas: • Three inches of AC over six inches of CRB, or • Three inches of AC over four and one-half inches of ATB. These pavement thicknesses may be modified based on anticipated traffic loads and frequency. Asphalt concrete (AC), asphalt treated base (ATB), and crushed rock base (CRB) materials should conform to WSDOT specifications. All rock base should be compacted to at least 95 percent of the ASTM D-1557-91 laboratory test standard. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Davis Avenue Associates, LLC E-9511 January 17, 2002 Page 16 LIMITATIONS Our recommendations and conclusions are based on the site materials observed, selective laboratory testing and engineering analyses, the design information provided to us by you, and our experience and engineering judgement. The conclusions and recommendations are professional opinions derived in a manner consistent with that level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area. No warranty is expressed or implied. The recommendations submitted in this report are based upon the data obtained from the test pits. Soil and groundwater conditions between exploration sites may vary from those encountered. The nature and extent of variations between our exploratory locations may not become evident until construction. If variations do appear, ECI should be requested to reevaluate the recommendations of this report and to modify or verify them in writing prior to proceeding with the construction. Additional Services We recommend that ECI be retained to perform a general review of the final design and specifications to verify that the earthwork and foundation recommendations have been properly interpreted and implemented in the design and in the construction specifications. We also recommend that ECI be retained to provide geotechnical services during construction. This is to observe compliance with the design concepts, specifications or recommendations and to allow design changes in the event subsurface conditions differ from those anticipated prior to the start of construction. We do not accept responsibility for the performance of the foundation or earthwork unless we are retained to review the construction drawings and specifications, and to provide construction observation and testing Earth Consultants, Inc. .I Irl M1rt IckST a _ sE �7�n Jw �J 43RD, $raiI�� { ST4C+4R�t RU9i `� ^ _ .Eeoza rC y 9 �' SE +rl . fit,; L _-) I `, sV rre15' IV-cz ;Hist �l r, s IN 4t' ' I i! �I- ,v,l rn IiJtl ST T .. 1.� v S: IL►el,l 1. k E N _ ��_ z _��n r. w-= I HI TH US 4 = SE Ient art 5151 x S icinrH ST CT _ a " �— tii tRk 5: 1 rflf.11 ;►ZMD ST .142101{ - 55TH HLILJ ST IiUTil :1. �� ST SE rgiT;r �` ■■ s 5.� +tea co CLGVE�.■7iv ■j��]] � 'I� �+I�I `spa 11_ .1 s .r ■, y Vl' I4~ fi: I if 1 .a 1=;•tnt r-1 S 196TH r} lllr 4T t n,�I r6• I cal L' ST I ��a7rr ,4 � ti� ir,; i '! I IiJ �', ��•: _ Pl�lk '7- till ja sI-z�+arsl_ Sri 2711 _ t 5E si 271.1 I II JA a ;NIS( I, S 202ND aa'— 5 02hll is ST 10 y4'L- 2WRU 4� S 2057N�ru, I 5T 1 a �elTM'� —� SES cIIII�ox k T lEII�~ ;Kul k F a J fc__ . ca , I " S±Pio6TH 'r _ S1 s "c0BT$ 5 a1 � 1%'fl! S.I Reference: Puget Sound Area King County / Map 686 By Thomas Brothers Maps Dated 2002 NOTE: This plate may contain areas of color. ECI cannot be responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. 3ftEarth Consultants, Inc. GeolechniCal Engineers. Geologists & Envirmtrienlal Scientists Vicinity Map Chateau Valley Center Renton, Washington Drwn. GLS Date Nov. 2001 Proj. No. 9511 Checked RAC Date 11/20/01 Plate 1 9V> I j TP-7 \ Approximate Scale W I I � � 0 30 60 120ft. UJ L j N I °I I \ \ CU I W \'� �\ 40 Lot 1 0 I –+ TP-6! [; \ EN� • TP-1 Approximate Location of C6 ECI T ECI Test Pit, Proj. No. I TP-8 Lot 11 ��^ E-9511, Nov. 2001 i -TrS - - JP-9 TP-5 - Subject Site ' t Lot 1 \ \ Proposed Building ` 100 I I � TP-11 \ \ I L — — — — —— TTP-4 _R-3 _ Utiles Easement l , –'� � —ITP=2 ` 1201. { - - - — - -\ .. ` � � 100 Utility Easement- -- NOTE: This plate may contain areas of color. ECI cannot be responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. Earth Consultants, Inc. Geotechnical Engineers, Geologists & Environmental Scientists Test Pit Location Plan Chateau Valley Center Renton, Washington Drwn. GLS Date Nov. 2001 Proj. No. 9511 Checked RAC Date 11/20/01 Plate 2 Temporary Slope (1.51-1 : 1 V Max.) Temporary Soldier Pile Wall H = 12' (Max.) Bottom of Excavation Use EFP = 300pcf Passive Pressure NOTES: Calculate Active Pressure using Equivalent Fluid Pressure (EFP) = 45pcf. For 1.51-1:11V slope above wall. For Horizontal Backfill use EFP = 35pcf. Apply Passive Pressure over 2 times the diameter of the Grouted Soldier Pile. Use EFP = 300pcf. Apply Traffic Surcharge of 70psf in rectangular distribution (where applicable). Traffic Surcharge (Where Applicable) Active Pressure -- Use EFP = 45pcf D = 1.51-1 (Min.) NOT - TO - SCALE CD rn CIS co CU U U a ry a �Q �CD 0- CD o� r` a CL a Q Earth Consultants, Inc. Geolectlnlcal Engineers, Geologists & Environmental scientists TEMPORARY CANTILEVER SOLDIER PILE WALL Chateau Valley Center Renton, Washington Drwn. GLS Date Dec. 2001 Proj. No. 9511 Checked RAC Date 1214101 Plate 3 H Varies 12 inches FF Elev. Varies 18" min. 18 inches min. T"NAY ti: �tii.}.• :`•e• :i, r' 1 Proj. No. 9511 Surface Seal; Native Soil or other low granular soil having no more than 5 Plate 4 Ogg 0 ❑ ❑e00Q P00 Ppn[❑ permeability Material percent passing the #200 sieve and 0 0 ❑ 17 0 ❑ aa� + ❑. •0 ❑ X0000 a 0o0 Op❑ 4 O: :,+a�� 6Q 0 000a U 0 • • +••+a% 17 ❑p Q P00 p °tl ❑ P O0 0°❑ u 0'3%0 P P o P 17° �q 0 ° 001 '• S s a 0 ac :ti:'•:;a; Structural Fill Backfill 90 percent relative o` �• '�` �°•-"- compaction O 0 p P a ° C), ❑ p Ptl : . ❑ O❑ ❑ 0 c 0p0 °°a❑°Q ❑� : . 0,C) C) 000 a❑p tl ° o °a O o pO0 ❑ o: �•" deleterious materials. It should be Excavated Slope Perforated Pipe Wrapped with Filter Fabric 1) Free draining backfill should consist of Date Dec. 2001 1 Proj. No. 9511 Surface Seal; Native Soil or other low granular soil having no more than 5 Plate 4 r;.::.: permeability Material percent passing the #200 sieve and no particles greater than 4 inches in ° °❑ °❑ 0 18 inches minimum of Free Draining diameter. The percentage of particles ab` ° ° ° Backfill passing the #4 sieve should be between 25 and 75 percent. :ti:'•:;a; Structural Fill Backfill 90 percent relative '�` �°•-"- compaction 2) Structural Fill backfill should be free of organics, clayey soils, debris and other ° °°°°° °° 1 inch Minus Rock or Pea Gravel deleterious materials. It should be placed at or below the optimum moisture content. 3) Drain pipe; perforated or slotted rigid PVC pipe laid with perforations or slots facing down; tight jointed; with a positive gradient. Do not use flexible corrugated plastic pipe. Drain line should be bedded on and surround with free draining 1 inch minus rock or pea gravel, as desired. The drain rock may be encapsulated with a geotechnical drainage fabric at the engineers discretion. SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING Earth Consultants, Inc. Geotechnical Engineers, Geologists & Environmental scientists RETAINING WALL DRAINAGE AND BACKFILL Chateau Valley Center Renton, Washington Drwn. GLS Date Dec. 2001 1 Proj. No. 9511 Checked RAC Date 12/4/01 Plate 4 WATERPROOFING PER ARCHITECTURAL PLAN WOOD LAGGING CONCRETE FACING CONTINUOUS MIRADRAIN 6000 _ OR EQUIVALENT (PLACED WITH FILTER FABRIC FACING SHORING) 2" DIAMETER PVC DRAIN PIPE I 6' O.C. I �= CONNECT TO PERIMETER -DRAIN TIGHTLINE VIII- SLAB -ON -GRADE FLOOR III (PER PLAN) NATIVE SOIL EXCAVATION NOTE: DRAIN THROUGH WALL SHOULD BE INSTALLED AT MIDDLE OF LAGGING. SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING Earth Consultants, Inc. Geotechnical Engineers, Geologists & Environmental Scientists SHORING WALL DRAINAGE Chateau Valley Center Renton, Washington Drwn. GLS Date Dec. 2001 III— 9511 .: :Q �. J. a, III=III 12/4/01 :4 a`. 4 .•, : e' a 5 •.r d.- r q� v 8 e �. PVC TIGHTLINE a IIITRucTfJRA1 a FILL. DRAIN GRATE _ •4 �. °' FOUNDATION '- (PER PLAN) III=���=III=III=III —111— =III NOTE: DRAIN THROUGH WALL SHOULD BE INSTALLED AT MIDDLE OF LAGGING. SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING Earth Consultants, Inc. Geotechnical Engineers, Geologists & Environmental Scientists SHORING WALL DRAINAGE Chateau Valley Center Renton, Washington Drwn. GLS Date Dec. 2001 Proj. No. 9511 Checked RAC Date 12/4/01 Plate 5 11 2 inch min. / 4 inch max. 12 inch min. SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING 18 inch min. 2 inch min. LEGEND Surface seal; native soil or other low permeability material. Fine aggregate for Portland Cement Concrete; Section 9-03.1(2) of the WSDOT Specifications. Drain pipe; perforated or slotted rigid PVC pipe laid with perforations or slots facing down; tight jointed; with a positive gradient. Do not use flexible corrugated plastic pipe. Do not tie building downspout drains into footing lines. Wrap with Mirafi 140 Filter Fabric or equivalent. Earth Consultants Inc. TYPICAL FOOTING SUBDRAIN DETAIL Chateau Valley Center Geaectinkal Fsglneers. GeobgLsis & FsWronrneroal Sciernlsts Renton, Washington A[ Proj. No. 9511 1 Drwn. GLS Date Dec. 2001 1 Checked RAC Date 12/4/01 Plate 6 a da , Slope To Drain ° o 'o - e o 6 inch min. •oma •o• .' i0o: ' .. .. .�, o •:,a �'.: ° ' o- 'd ; a'°': ��•-��= �.• :� ° � 4 inch min. ° - Diameter a'o;•:: ! •�'. : '°:.^' ; �.. -° °° 6 0 ° °' °' ''•:'�� o : °° ' ° Perforated Pipe—! ;;, : ° ° Wrapped in Drainage ::=' - •~'.=a. '� o ° ` oo ;� • ° °�° °a°�o �� Fabric �;• ���; : d 2 inch min. / 4 inch max. 12 inch min. SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING 18 inch min. 2 inch min. LEGEND Surface seal; native soil or other low permeability material. Fine aggregate for Portland Cement Concrete; Section 9-03.1(2) of the WSDOT Specifications. Drain pipe; perforated or slotted rigid PVC pipe laid with perforations or slots facing down; tight jointed; with a positive gradient. Do not use flexible corrugated plastic pipe. Do not tie building downspout drains into footing lines. Wrap with Mirafi 140 Filter Fabric or equivalent. Earth Consultants Inc. TYPICAL FOOTING SUBDRAIN DETAIL Chateau Valley Center Geaectinkal Fsglneers. GeobgLsis & FsWronrneroal Sciernlsts Renton, Washington A[ Proj. No. 9511 1 Drwn. GLS Date Dec. 2001 1 Checked RAC Date 12/4/01 Plate 6 Backfill Bedding -Road Pavement or Concrete Floor Slab a�a o o Base Rock Non -Load Supporting Floor Slab or Areas Roadway Areas r- Backfill; Compacted On -Site Soil or Suitable Imported Fill Material. Minimum Percentage of Maximum 90 Laboratory Dry Density as determined by ASTM Test Method D 1557-91 (Modified Proctor), unless otherwise specified in the attached report text. M®M® Bedding Material; material type depends RE'�� �e e on type of pipe and laying conditions. Bedding should conform to the manufacturers recommendations for the type of pipe selected. Varies 1 foot min. Varies Varies SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING Earth Consultants, Inc. Geolechnical Engineers, Geologists & Environmental Scienllsts TYPICAL UTILITY TRENCH FILL Chateau Valley Center Renton, Washington Drwn. GLS Date Dec. 2001 Proj. No. 9511 Checked RAC Date 12/4/01 Plate 7 M APPENDIX A FIELD EXPLORATION E-9511 Our field exploration was performed on November 2, 2001. The approximate test pit locations were determined from existing landmarks presented on available plans. The locations of the test pits should be considered accurate only to the degree implied by the method used. These approximate locations are shown on the Test Pit Location Plan, Plate 2. The field exploration was continuously monitored by a geologist from our office, who classified the soils encountered and maintained a log of each test pit, obtained representative samples, measured groundwater levels, and observed pertinent site features. All samples were visually classified in accordance with the Unified Soil Classification System that is presented on Plate Al, Legend. Logs of the test pits are presented in the Appendix A, Plates A2 through A10. The final logs represent our interpretations of the field logs and the results of the laboratory tests of field samples. The stratification lines on the logs represent the approximate boundaries between soil types. In actuality, the transitions may be more gradual. Earth Consultants, Inc. Topsoil GRAPH LETTER Fill MAJOR DIVISIONS iSYMBOL SYMBOL TYPICAL DESCRIPTION 24" I.D. RING OR SHELBY TUBE SAMPLER GraGW SAMPLER PUSHED e o * Well -Graded Gravels, Gravel -Sand AndVel Clean Gravels 0 Q Q gW Mixtures, Little Or No Fines 4� GP Poorly -Graded Gravels, Gravel - PLASTIC INDEX Gravelly (little or no fines)Ilr Coarse Soils � , ■ gp Sand Mixtures, Little Or No Fines Grained Ro. GM Silty Gravels, Gravel -Sand - Soils More Than 50°/ Coarse Gravels With log gm Silt Mixtures Fraction Fines ( appreciable GC Clayey Gravels, Gravel - Sand - Retained On amount of fines) No. 4 Sieve gC Clay Mixtures Sand , ,o oe ,e SW Well -Graded Sands, Gravelly And Clean Sand o o d SW Sands, Little Or No Fines More Than Sandy (little or no fines) SP Poorly -Graded Sands, Gravelly 50% Material Soils Sp Sands, Little Or No Fines Larger Than More Than No. 200 Sieve 50% CoarseSM Sands With Sm Silty Sands, Sand - Silt Mixtures Size Fraction Fines (appreciable j '' SC Clayey Sands, Sand Clay Mixtures No.4 Se amount of fines) eng SC ML Inorganic Silts & Very Fine Sands, Rock Flour,Silty- ml Clayey Fine Sands; Clayey Silts w/ Slight Plasticity Fine Silts Liquid Limit CL Inorganic Clays Of Low To Medium Plasticity, Grained And Less Than 50 Cl Gravelly Clays, Sandy Clays, Silty Clays, Lean Soils Clays 1 1 1 1 1 QL Organic Silts And Organic 1 1 1 1 1 1 1 OI Silty Clays Of Low Plasticity I H Inorganic Silts, Micaceous Or Diatomaceous Fire More Than mh Sand Or Silty Soils 50% Material Smaller T#,anAnd Silts Liquid Limit CH InorgaNc Clays Of High No 200 Sieve Clays Greater Than 50 Ch Plasticity, Fat Clays. Size j OH Organic Clays Of Medium To High oh Plasticity, Organic Silts Peat, Humus, Swamp Soils Highly Organic Soils pt With High Organic Contents Topsoil ' y y y J Humus And Duff Layer Fill PENETROMETER READING, tsf Highly Variable Constituents The discussion in the text of this report is necessary for a proper understanding of the nature of the material presented in the attached logs. DUAL SYMBOLS we used to indicate borderline soll classification. C TORVANE READING, tsf T 2" O.D. SPLIT SPOON SAMPLER qu PENETROMETER READING, tsf W MOISTURE, % dry weight 24" I.D. RING OR SHELBY TUBE SAMPLER P SAMPLER PUSHED * SAMPLE NOT RECOVERED WATER OBSERVATION WELL pcf DRY DENSITY, lbs. per cubic ft. LL LIQUID LIMIT, % 4 DEPTH OF ENCOUNTERED GROUNDWATER PI PLASTIC INDEX DURING EXCAVATION tft)Earth Consultants Inc. 6c"im Imi(LI rAighwurs, 0%)lublsls & Eiwiftmink-Wai Scicillus It SUBSEQUENT GROUNDWATER LEVEL W/ DATE LEGEND Proj. No. 95 11 1 Date Nov. 10 1 1 Plate Al Test Pit Log Project Name: Sheet of Chateau Valley Center 1 1 1 Job No. Logged by: Date: Test Pit No.: 9511 KS 11/2/01 TP -1 Excavation Contactor: Ground Surface Elevation: _ NW Excavating 118' Notes: — General Notes W (%) — n$ N L v g .: a p r` M v$ Surface conditions: Depth of Topsoil & Sod 2": blackberries SM Broom silty SAND, loose, moist (Fill) 1 10.5 2 3 17.9 4 Brown silty SAND, medium dense, moist SM 5 21.3 6 ML Gray sandy SILT, medium dense, very moist 7 8 -mottled brown/gray banding 16.6 9 -native -52% fines 10 -becomes dense SM Brown silty SAND with gravel, dense, moist 11 Testpit terminated at 11.0 feet below e>asting grade. Groundwater seeps a encountered at 7.0 feet during excavation. NOTTest pit excavations performed by a CASE 9010B Track Hoe Excavator - Elevations estimated from a Topographic Plan by Touna Engineers, dated Nov. 1997. Earth Consultants Inc. Test Pit Log Chateau Valley Center Gra finical F]nsim eas. Gook)sls1+R nwronmenral Sden%m Renton, Washington Proj. No. 9511 Dwn. GLS Date Nov. 2001 Checked RAC Date 11/26/01 Plate A2 Subsurtace conditions depicted represent our observations at the time and location of this exploratory hole, modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. We cannot accept responsibility for the use or interpretation by others of ufn rn firm nrmenlerY nn fhic fir... Test Pit Log Project Name: Chateau Valley Center Sheet of 1 1 Job No. Logged by: Date: Test Pit No.: 9511 [ KS 11/2/01 TP -2 Excavation Contactor. Ground Surface Elevation: NW Excavating 116' Notes: - General Notes W C%) — L CL kn t „ _ a CO10 N $ D cn Surface Conditions: Depth of Topsoil & Sod 4": trees / blackberries 18.8 15.8 10.7 1 2 3 4 5 6 7 8 s 10 ML Gray sandy SILT, medium loose, very moist -mottled -51 % fines SM Brown silty SAND with gravel, dense, moist -slightly cemented Test pit terminated at 10.0 feet below e)asting grade. No groundwater encountered during excavation. 3ft Earth Consultants Inc. Crotfflink`alMglnems,Gex,loglsis&EnvimnmenralSde.wisA Test Pit Log Chateau Valley Center Renton, Washington Proj. No. 9511 Dwn. GLS Date Nov. 2001 Checked RAC Date 11/26/01 Plate A3 5unsurrace condlnons depicieks represent our onservar{ons at the time and location or this explaratory hole, modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. We cannot accept responsibility for the use or interpretation by others of r�eM-4 ..., W. I— Test Pit Log Project Name: Chateau Valley Center Sheet of 1 1 Job No. Logged by: Date: Test Pit No.: 9511 1 KS 11/2/01 TP -3 Excavation Contactor: Ground Surface Elevation: NW Excavating Notes: General Notes W (%) E. c7 to a o u -M m > >. rn Surface Conditions: Depth of Topsoil & Sod 4": blackberries 16.4 18.5 23.6 1 2 3 4 5 6 7 8 s 10 ML Gray sandy SILT, medium dense, moist, with organics ML Brown to gray sandy SILT, medium dense, moist -with gravel, cobbles -mottled SM Gray silty SAND with gravel, medium dense, very moist Test pit terminated at 10.5 feet below e)asbng grade. No groundwater encountered during excavation. Earth Consultants Inc. CW.Ok tinIcaI Finsinerar; Grcdngl%N & Fnv1mnmrnra15clrntt s Test Pit Log Chateau Valley Center Renton, Washington Proj. No. 9511 Dwn. GLS Date Nov. 2001 Checked RAC Date 11/26/01 Plate A4 Subsurtace conartlons depicted represent our observations at the time and location of this exploratory hole, modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. We cannot accept responsibility for the use or interpretation by others of infnrmn}inn nraq an+cf} nn +Hie Inn Test Pit Log Project Name: Sheet of Chateau Valley Center t 1 1 Job No. Logged by: Date: Test Pit No.: _9511 1 KS 11/2/01 TP -4 Excavation Contactor: Ground Surface Elevation: NW Excavating 105' Notes: — - - -• General Notes WCL M 0 COCO a ,; n p C$ CO Surface conditions: Depth of Topsoil & Sod 8": trees / blackberries 17.8 18.8 11.7 14.4 v o° 0 6 a ° ° 2 3 4 5 6 8 9 10 11 12 ML Gray to brown sandy SILT with gravel, medium dense, very moist -with organics -mottled -seepage at 2' SM Brown silty SAND with gravel, medium dense, very moist -42% fines SP -SM Brown poorly graded SAND with silt and gravel, medium dense, wet -7% fines -becomes very dense at 11' -with cobbles at 11.5' Test pit terminated at 12.0 feet below existing grade. Groundwater seepage encountered at 2.0 and 7.0 feet during excavation. 3W Earth Consultants Inc. CKxKedmlralFnginem,Gm*)tltils&Fnvlmnn"talsdentl. - Test Pit Log Chateau Valley Center Renton, Washington Prcj. No. 9511 Dwn. GLS Date Nov. 2001 Checked RAC Date 11/26/01 Plate A5 �Subsurrace conditions depicted represent our observations at the time and location of this exploratory hole, modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. We cannot accept responsibility for the use or interpretation by others of in fnr.n a+inn nrovonfe.-I nn ffifc Iry Test Pit Log Project Name: Chateau Valley Center Sheet ot 1 1 Job No. 9511 Logged by: 1 KS Date: 11/2/01 Test Pit No.: TP -5 Excavation Contactor: Ground Surface Elevation: NW Excavating 104' Notes: General Notes W (0/0) n m : , 129 rn a .: a p LLM rn 0 >. , Surface Conditions: Depth of Topsoil & Sod 8": trees / blackberries 10.5 10.5 13.8 13.6 1 2 3 4 5 6 7 8 s 10 11 SM Brown silty SAND, medium dense, dry (Fill) -with organics -34% fines ML Gray to brown sandy SILT, medium dense, moist (Native) Brown silty SAND with gravel, medium dense, moist -becomes sandier at 9' ~ Test pit terminated at 10.0 feet below eAsting grade. No groundwater encountered during excavation. SM Earth Consultants Inc. rt�iinital nnsinftit�GP.(*VsA& F]nvinxxlx`nfal Soon*"— Test Pit Log Chateau Valley Center Renton, Washington Proj. No. 9511 Dwn. GLS Date Nov. 2001 1 Checked RAC Date 11/26/01 Plate A6 5uusurtace conditions depicted represent our odkservation s at the time and location of this exploratory hole, modified by engineering tests, analysis and Julgment. They are not necessarily representative of other times and locations. We cannot acoept responsibility for the use or interpretation by others of �nfnrmoOinn n !Y_ _4 nn Ohio !nn Test Pit Log Project Name: Sheet of Chateau Valley Center 1 1 _ _ Job No. Logged by: Date: Test Pit No.: 9511 KS _ _ 11/2/01 TP -6 I Excavation Contactor: Ground Surface Elevation: NW Excavating 112' Notes: General Notes W (U/0) n E j!o CO$ (9m L CL n .:c.) " m $ j rn Surface Conditions: Depth of Topsoil & Sod 2": blackberries al SM Brown silty SAND, medium dense, moist (Fill) TPSL TOPSOIL 2 ML Gray sandy SILT, medium dense, moist (Native) 3 15.0 4 -mottled 5 6 7 14.4 6 9 Test pit terminated at 9.0 feet below eAsting grade. No groundwater encountered during excavation. Earth Consultants Inc. Test Pit Log Chateau Valley Center Ge�treYmtral Fnglneras. GeoklglsA Ra Fnvlmnnx:nral Sclenrisrs Renton, Washington Proj. No. 9511 Dwn. GLS Date Nov. 2001 Checked RAC Date 11/26/01 Plate A7 5utisurtace conditions depicted represent our observations at the time and location of this exploratory hole, modified by engineering tests, analysis and judgment. They are not necessarily representatnre of other times and locations. We cannot accept responsibility for the use or interpretation by others of infnrmv}.nn r.roCanfc✓i nn FI'lIC IM Test Pit Log Prged Name: Chateau Valley Center Sheet of 1 1 Job No. I Logged by: Date: Test Pit No.: 9511 KS 11/2/01 .—TP -7 Excavation Contactor: Ground Surface Elevation: NW Excavating 115' Notes: Notes General(0/0) �O – E E „ m LL E co E Surface Conditions: Depth of Topsoil & Sod 2": grass 12.2 2 3 4 5 6 7 SM Brown silty SAND, medium dense, moist ML Brown to gray sandy SILT, medium dense, moist -mottled Test pit terminated at 7.5 feet below existing grade. No groundwater encountered during excavation. Earth consultants Inc. GrX*". inicaln,si"ftTe, ,.w,&F�,w'"nwenralsde sm- Test Pit Log Chateau Valley Center Renton, Washington Proll. No. 9511 Dwn. GLS Date Nov. 2001 Checked RAC Date 11/26/01 Plate A8 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole, modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. We cannot accept responsibility for the use or in terpretali on by others of in'= -ht— nroc-M-4 — #hie IM Test Pit Log Prged Name: Sheet of _ Chateau Valley_ Center 1 1 _ Job No. Logged by: Date: Test Pit No.: 9511 1 KS 11/2/01 TP -8 Excavation Contactor: Ground Surface Elevation: NW E) cavating 112' Notes: General wr (0/p) S CL 129o t _;a I&Notes ILL CO � CO Surface Conditions: Depth of Topsoil & Sod 8": blackberries ML Brown to gray sandy SILT, medium dense, very moist 1 2 3 4 20.7 5 SM Brown silty SAND with gravel, dense, moist 6 -47% fines 11.6 7 Testp� It terminated at 7.0 feet below eAstin g grade. No groundwater encountered during excavation. Earth Consultants Inc. Test Pit Log Chateau Valley Center Cr.M"111 IFiislnftn.Gook>FlL' :RFnvrmnnx.nralSdmftsts Renton, Washington Proj. No. 9511 Dwn. GLS Date Nov. 2001 1 Checked RAC Date 11/26/01 Plate A9 ourau1:1211n wnusuwrs uepuaeu reprusent our ooservations at tnelime ana locanon of ints expioramry note, moditiea by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. We cannot accept responsibility for the use or interpretation try others of nfnnnofinn nnnventm nn 4hie I� Test Pit Log Project Name: Sheet of Chateau Valley Center 1 1 Job No. Logged by: Date: Test Pit No.: 9511 1 KS _ 11/2/01 TP -9 Excavation Contactor: Ground Surface Elevation: NW E):avating 107' Notes: General Notes W (%) t $ a E = a n LL o LL CO U $ =) CO Surface Conditions: Depth of Topsoil & Sod 12": trees ML Gray to brown sandy SILT, medium dense, very moist 1 2 3 4 18.6 5 6 7 8 Brown silty SAND with gravel, dense, moist SM s Test pit terminated at 9.0 feet below e)asting grade. No groundwater encountered during e) cavation. Earth Consultants Inc. Test Pit Log Chateau Valley Center GaokfciiniraI Biglnftff- , Geolk)S v- & Fnvirmin enrol scimtu Renton, Washington Proj. No. 9511 Dwn. GLS Date Nov. 2001 Checked RAC Date 11/26/01 Plate A10 �us,sulldkx fAHRUiklun5 uapicm represeni our ooservauons ai ine time ana uscation at tnis expiaraiory mole, MOO lied by engineering tests, analysis and !udgment. They are not necessarily representative of other times and locations. We cannot accept responsibility for the use or interpretalion by others of f n11p}fnn 1'I*nCOf'1+Ali - {�1IC iM APPENDIX B LABORATORY TESTING RESULTS E-9511 Earth Consultants, Inc. 4 Copies DISTRIBUTION E-9511 Davis Avenue Associates, LLC P.O. Box 907 Woodinville, Washington 98072 Attention: Mr. Darrell Johnson Earth Consultants, Inc.