HomeMy WebLinkAboutRS_GeotechReport_SEE_170307_v1 Job No. 1701 S&EE S&EE GEOTECHNICAL REPORT KING COUNTY REGIONAL AFIS LAB 900 OAKESDALE AVE. SW, RENTON, WA S&EE JOB NO. 1701 MARCH 7, 2017 1701rpt S&EE TABLE OF CONTENTS Section Page 1.0 INTRODUCTION ................................................................................................................................................. 1 2.0 SCOPE OF WORK ............................................................................................................................................... 1 3.0 SITE CONDITIONS ............................................................................................................................................. 2 3.1 SITE GEOLOGY ................................................................................................................................................ 2 3.2 SURFACE AND SUBSURFACE CONDITIONS ............................................................................................... 3 4.0 LABORATORY TESTING ................................................................................................................................. 3 5.0 ENGINEERING EVALUATIONS AND RECOMMENDATIONS ................................................................. 4 5.1 SEISMIC CONSIDERATIONS .......................................................................................................................... 4 5.1.1 LIQUEFACTION .......................................................................................................................................... 4 5.1.2 SITE CLASS ................................................................................................................................................. 4 5.2 FOUNDATION SUPPORT ................................................................................................................................ 5 5.3 UNDERGROUND UTILITY CONSTRUCTION .............................................................................................. 7 5.3.1 TEMPORARY SLOPE AND SHORING ....................................................................................................... 7 5.3.2 SUBGRADE PREPARATION ..................................................................................................................... 7 5.3.3 DEWATERING ............................................................................................................................................ 8 5.3.4 BUOYANCY RESISTANCE ......................................................................................................................... 8 5.4 LATERAL EARTH PRESSURES ON UNDERGROUND WALLS ................................................................. 9 5.5 SITE PREPARATION AND STRUCTURAL FILL ........................................................................................ 10 5.6 SLAB-ON-GRADE .......................................................................................................................................... 11 5.7 PAVEMENT DESIGN RECOMMENDATIONS ............................................................................................ 11 5.8 ADDITIONAL SERVICES .............................................................................................................................. 12 6.0 CLOSURE ............................................................................................................................................................. 12 FIGURE 1: SITE LOCATION MAP FIGURE 2: SITE & EXPLORATION PLAN FIGURE 3: LIQUEFACTION MAP FIGURE 4: GENERALIZED SOIL PROFILE FIGURE 5: RESULTS OF LIQUEFACTION ANALYSES FIGURE 6: SOIL PROPERTIES USED IN PILE ANALYSES FIGURE 7: RESULTS OF LATERALLY LOADED PILE APPENDIX A: FIELD EXPLORATION, LOG, AND SOIL CLASSIFICATION CHART APPENDIX B: LABORATORY TEST RESULTS 1701rpt S&EE 1 REPORT OF GEOTECHNICAL INVESTIGATION KING COUNTY REGIONAL AFIS LAB For Buffalo Design 1.0 INTRODUCTION We present in this report the results of our geotechnical investigation for the proposed King County Regional AFIS (Automated Fingerprint Identification System) Lab located at 900 Oakesdale Ave. SW, Renton, Washington. The project site is located in the northeastern portion of an office park. A Site Location Map is shown in Figure 1 and a Site & Exploration Plan is shown in Figure 2, both are included at the end this report. We understand that the project will involve a building addition measuring 44 feet by 66 feet for vehicle processing laboratory. This new space will be connected to the existing building with 18 feet long by 16 feet wide corridor. The new structure will be single story and 23 feet in height. The entrance to the corridor will be through an opening of an existing window in the existing building exterior wall. We understand from the project structural engineer that the column and wall loads will be 30 kips and 1.1 kips/feet, respectively. Floor load will be 250 pounds per square feet. The site is relatively flat. As such, cut and fill will be minimal. New underground utilities will include storm and sewer lines. 2.0 SCOPE OF WORK The purpose of our investigation is to provide geotechnical parameters and recommendations for design and construction. Specifically, the scopes of our services have included the followings: 1. Review of available geotechnical data in our file. 2. Exploration of the subsurface conditions at the site by the drilling of 2 soil test borings. 3. Obtain representative soil samples and transport to our sub-contracted soil laboratory for testing. 4. Recommendations regarding foundation supports of the proposed building. 5. Recommendation regarding slab support. 1701rpt 2 S&EE 6. Performance of liquefaction analyses and recommendations regarding seismic design. 7. Recommendations regarding passive, active and at-rest earth pressures and coefficient of friction for the resistance of lateral loads. 8. Recommendations regarding site preparation, suitability of onsite soils for use as fill, types of suitable imported fill, fill placement techniques, and compaction criteria. 9. Recommendations regarding angles of temporary and permanent slopes. 10. Recommendations regarding underground utility construction; recommendation regarding excavation shoring and construction dewatering, if necessary. 11. Recommendations regarding flexible and rigid pavement designs. We will provide subgrade CBR value for flexible pavement and subgrade reaction modulus for rigid pavement designs. 12. Preparation of a geotechnical report containing a site plan, a description of subsurface conditions, and our findings and recommendations. 3.0 SITE CONDITIONS 3.1 SITE GEOLOGY Published geologic information indicates that the site is underlain by alluvium (Qaw). These soils are chiefly sand, silt, and clay deposited by the White and Green Rivers before the diversion of the White River to the south in 1906. The upper parts of these alluvial are mostly clayey silt and fine sand with thickness ranges from 30 to 40 feet near Tukwila. The lower parts are mostly medium and coarse sand that are more than 75 feet in thickness. (Geologic map of the Renton Quadrangle, King County, Washington by D.R. Mullineaux, 1965, USGS) Seismic Hazards The project site is under the threat of the movement of Seattle Fault. This fault is a collective term for a series of four or more east-west-trending, south-dipping fault strands underlying the Seattle area. This thrust fault zone is approximately 2 to 4 miles wide (north-south) and extends from the Kitsap Peninsula near Bremerton on the west to the Sammamish Plateau east of Lake Sammamish on the east. The four fault strands have been interpolated from over-water geophysical surveys (Johnson, et al., 1701rpt 3 S&EE 1999) and, consequently, the exact locations on land have yet to be determined or verified. Recent geologic evidence suggests that movement on this fault zone occurred about 1,100 years ago, and the earthquake it produced was on the order of a magnitude 7. A liquefaction map (Figure 3: Preliminary Liquefaction Susceptibility Map of the Renton Quadrangle, Washington by Stephen Palmer) indicates that the project area has high liquefaction susceptibility. 3.2 SURFACE AND SUBSURFACE CONDITIONS The proposed AFIS lab is located in a parking area behind (at the northeastern corner of) the existing building. The area is relatively flat. Underground utilities in the area include stormdrain and gas lines. According to the as-built foundation plan (11-9-90), the existing 3-story building is supported on 16-inch diameter augercast piles having 55 and 75 tons capacities. On September February 2, 2017, we explored the subsurface condition at the site by the drilling of 2 soil test borings. The locations of these borings are shown on Figures 2 - Site & Exploration Plan. The boring logs are included in Appendix A of this report. A generalized soil profile is shown in Figure 4. The boring data show that the subsurface conditions at the site include fill over native soils. The fill is about 5 to 6 feet in thickness and includes loose to medium dense, sand, silty sand and silt. The native soils below the fill include 15.5 feet of very soft and very loose, silt, clay and silty sand. We believe these soils represent the upper part of the alluvium indicated in the geologic map. The soils under this upper alluvium include medium dense to very dense sand and gravel. We believe these soils represent the lower alluvium. Both borings ended in this unit. Groundwater was encountered at a depth of 6 feet 8 inches at the time of drilling. Based on our experience with the subsurface conditions in the site vicinity, we believe that the depth of groundwater is affected by precipitation. We expect that the groundwater may fluctuate between about 6 to 10 feet below ground surface. 4.0 LABORATORY TESTING The soil sample at the depth of 11.5 feet from Boring B-2 was transported to our sub-contracted laboratory, Materials Testing & Consulting, for consolidation testing of the silty/clayey soil. The soil properties were used in the evaluation of consolidation (long-term) settlement. The test results are included in Appendix B. 1701rpt 4 S&EE 5.0 ENGINEERING EVALUATIONS AND RECOMMENDATIONS 5.1 SEISMIC CONSIDERATIONS 5.1.1 LIQUEFACTION As mentioned previously, the project site is under the threat of earthquakes from Seattle fault. Based on US Geologic Survey, the intensity or Peak Ground Acceleration (PGA) from this crustal event will be about 0.6g. Liquefaction is the primary geotechnical impacts from such earthquakes. Liquefaction is a condition when vibration or shaking of the ground results in the excess pore pressures in saturated soils and subsequent loss of strength. Liquefaction can result in ground settlement. In general, soils that are susceptible to liquefaction include saturated, loose to medium dense sands and soft to medium stiff, low- plasticity silt. The evaluation of liquefaction potential is complex and is dependent on many parameters including soil’s grain size, density, and level of ground acceleration and duration of vibration. We performed liquefaction analyses for the project site using a computer program, Lique-Pro. The results are shown in Figure 5. As indicated in the figure, liquefaction will occur in the loose/soft zone from groundwater table to a depth of 21.5 feet, and a pocket of medium dense soil at about 40 feet. Ground settlement of about 2.5 inches may occur. This settlement will result mostly from the loose/soft soils in the upper 21.5 feet, and very slightly from the medium dense soils below 21.5 feet. 5.1.2 SITE CLASS The geotechnical-related parameters for seismic design are evaluated as described in Section 1613.3 of the 2015 IBC Code. From USGS website and using a site latitude of 47.47 degrees and a longitude of -122.23 degrees, the spectral response values for Site Class B (rock) are: SS = 1.450 g (short period, or 0.2 second spectral response) S1 = 0.542 g (long period, or 1.0 second spectral response) The Site Class is selected using the definitions in Chapter 20 of ASCE 7-10 considering the average properties of soils in the upper 100 feet of the soil profile at the site. Using the boring data, we determined that the subsoils correspond to Site Class E (“Soft Clay Soil”) in Table 20.3-1 (ASCE 7-10). The site coefficient values, obtained from Section 1613.3.3 of the 2015 IBC, are used to adjust the 1701rpt 5 S&EE mapped spectral response acceleration values to get the adjusted spectral response acceleration values for the site. The recommended Site Coefficient values for Site Class E are: Fa = 0.9 (short period, or 0.2 second spectral response) Fv = 2.4 (1.0 second spectral response) The most recent USGS Earthquake Hazards Map (U.S. Geologic Survey web site, 2008 data) has indicated that a horizontal peak acceleration (PGA) of 0.6 g is appropriate for a 4,275-year return period event, i.e. an event having a 2 percent chance of being exceeded in 50 years. 5.2 FOUNDATION SUPPORT Due to the risk of liquefaction, we recommend that the proposed building be supported by concrete augercast piles. We recommend that the pile be 16-inch in diameter with the pile tip embedded at a depth of 35 feet below the ground surface. The minimum pile spacing should be 5 feet on center. Pile Capacities: The pile will develop a total downward capacity of 88 kips. This capacity is obtained with the reduced soil strengths under the liquefaction condition, and includes an allowable working load of 70 kips and a downdrag force of 18 kips after liquefaction. The allowable upward capacity is 20 kips. These capacities include a safety factor of about 1.5 and 2.0 under the static and seismic conditions, respectively. Figure 6 shows the soil parameters used in the evaluations. Response to Lateral Load: Figure 7 shows that the top of pile deflection will be about ½ inch when subjected to a lateral load of 10 kips. The evaluation assumes a free head connection. The figure also shows that the point of reflection is located at about 14.5 feet below the top of pile. We recommend a point of fixity of 18 feet for design. Additional Lateral Resistance: Additional resistance to lateral loads will be provided by passive soil pressure against pile caps and grade beams. Assuming that structural fill is used for the backfill, an equivalent fluid density of 200 pounds per cubic foot (pcf) may be used for design. The criteria for the structural fill are presented in Section 5.5 of this report. Pile Settlements: Pile settlement will result from elastic compression of the piles and the supporting soils. The settlement is estimated to be about 1/2 inches, and will occur rapidly, essentially as the loads are applied. 1701rpt 6 S&EE Pile Installation: Cement grout must be pumped continuously during withdrawal of the auger, the rate of which should not exceed about 5 to 8 feet per minute. Also, at least 10 feet of grout head must be maintained during the entire withdrawal. We anticipate that the grout volume discharged from the pump to be about 1.2 to 1.5 times the theoretical volume of the drilled hole. The grout volume is usually obtained by counting the number of pump strokes. The grout pressure at the pump should be maintained in the range of 150 to 350 psi, depending on the length of the feeder hose used. The drilling contractor should provide pressure gages and stroke counters at the pump prior to drilling. Quality Control: The piling contractor must implement the following quality control measures. 1. Prior to pile installation, the contractor should provide historical data regarding the volume of grout output per stroke of their pump. If this is not available, the contractor should calibrate the grout pump by filling a 55-gallon drum. This calibration should be performed a minimum of two times and approved by our onsite inspector. 2. Prior to casting, the operator should lift auger 6 to 12 inches at start of grout pumping to facilitate tip plug removal, then return to previously established tip elevation before withdrawal. An initial grout head of 10 feet should be developed before start of auger withdrawal and maintained during extraction. 3. Volume of placed grout should be at least 120 percent of theoretical volume of the hole. 4. If grout pumping is interrupted during placement, the auger should be lowered a minimum of 5 feet before resuming withdrawal. 5. All debris fall into grout column must be removed before the installation of rebar cage. 6. The rebar cage should be equipped with centralizers and the cage should be plumb before inserting into the drilled-hole. Single cable hooked on one side of the cage, or any other mean resulting in tilting of the cage is not allowed. The cage should sink to the design depth by its own weight. Pushing the cage down by machine is not allowed. If grout de-hydration or any other reason preventing smooth cage installation, the hole should be re-drilled and re-grouted. 7. For adjacent piles that are less than 5 feet clear space, the minimum waiting period for installation should be 12 hours. 1701rpt 7 S&EE 8. Pile installation should be monitored by an inspector from our office. Our inspector will evaluate the adequacy of the construction methods and procedures. Any problems which might arise, or deviations from the specifications, will be considered during our evaluations and approval of each pile installed. 5.3 UNDERGROUND UTILITY CONSTRUCTION 5.3.1 TEMPORARY SLOPE AND SHORING Temporary cuts less than 6 feet in depth and above groundwater table can be sloped at 1H:1V, and shoring is likely required for cuts over 6 feet depth and below groundwater table. A variety of shoring methods has been used for the similar soils, including trench boxes, steel sheets, timber lagging, and steel sheetpile. We recommend the following soil parameters for any shoring method that requires structural designs. • Soil’s total unit weight: 125 pcf (pounds per cubic feet) • Soil’s buoyant unit weight: 60 pcf • Active soil pressure: 45 pcf, equivalent fluid density, above groundwater table • Active soil pressure: 21 pcf, equivalent fluid density, below groundwater table • Passive soil pressure: 200 pcf, equivalent fluid density, above groundwater table (include 1.5 safety factor) • Passive soil pressure: 125 pcf, equivalent fluid density, below groundwater table (include 1.5 safety factor) Please note that hydrostatic pressures should be included at both the active and passive sides of the shoring, and the pressure will depend on the type of dewatering method. A 2-foot over-excavation depth at the passive side should be considered in the design. 5.3.2 SUBGRADE PREPARATION All loose soil cuttings should be removed from the subgrade prior to the placement of bedding materials. Wet and loose subgrades may be encountered. The contractor should make efforts to minimize subgrade disturbance, especially during the last foot of excavation. Subgrade disturbance in wet and loose soil may be inevitable, and stabilization is necessary in order to avoid re-compression of the disturbed soils. Depending on the degrees of disturbance, the stabilization may require a layer of quarry spalls (4 to 6 inches size crushed rock). Based on our experience with the site soils, when compacted by the bucket of an excavator, a 12 to 18 inches thick layer of spalls would sink into the loose and soft subgrade, interlock 1701rpt 8 S&EE and eventually form a stable subbase. A chocker stone such as 1-1/4” clean crushed rock should be installed over the quarry spalls. This stone should be 4 to 6 inches in thickness and be compacted to a firm and non-yielding condition using a vibratory plated compactor that weighs at least 1,000 pounds. In the event that soft silty soils above groundwater table are encountered at subgrade, the subgrade should be over-excavated for a minimum of 6 inches. A non-woven geotextile having a minimum grab tensile strength of 200 pounds should be installed at the bottom of the over-excavation and the over-excavation be backfilled with 1-1/4” minus crushed rock. The geotextile should be installed flat with all wrinkles removed and have 12 inches overlap. The rock should be compacted to a firm a non-yielding condition using the same compactor. 5.3.3 DEWATERING Dewatering will be required for excavations deeper than the groundwater table. Based on our experience with the similar subsoils, we believe that for excavation shallower than about 6 feet, dewatering can be successful using local sumps. The contractor should install sumps at locations and spacing that are best fitted for the situation. To facilitate drainage, the sump holes should be at least 2 feet below the excavation subgrade. Also, the granular backfill around the sump should make hydraulic connection with the crushed rock and quarry spalls placed for subgrade stabilization. For excavation deeper than 6 feet, our experience has shown that wellpoints at 5 to 8 feet spacing would provide adequate dewatering, depending on the size of excavation and drawdown requirement. The contractor may need to retain a dewatering specialist for a detailed dewatering design. 5.3.4 BUOYANCY RESISTANCE The subsoils below groundwater table will liquefy during strong earthquakes. As such, buoyancy force should be considered in the design. If the self-weight of the structure and equipment is insufficient to resist the buoyancy force, an extended base can be considered for additional resistance. In this case, the additional resistance can be calculated using the weight of the soil above groundwater table and above the extended base. A soil’s unit weight of 125 pounds per cubic feet (pcf) can be used for this purpose. Sidewall friction should be ignored. 1701rpt 9 S&EE 5.4 LATERAL EARTH PRESSURES ON UNDERGROUND WALLS Lateral earth pressures on permanent retaining walls, underground vaults or utility trenches/pits, and resistance to lateral loads may be estimated using the recommended soil parameters presented in the following table. Equivalent Fluid Unit Weight (PCF) Coefficient of Friction at Base Active At-rest Passive Structural fill 45 60 200 0.4 Note: Hydrostatic pressures are not included in the above lateral earth pressures. The at-rest case applies to unyielding walls, and would be appropriate for walls that are structurally restrained from lateral deflection such as basement walls, utility trenches or pits. The active case applies to walls that are permitted to rotate or translate away from the retained soil by approximately 0.002H to 0.004H, where H is the height of the wall. The passive earth pressure and coefficient of friction include a safety factor of 1.5. SURCHARGE INDUCED LATERAL LOADS Additional lateral earth pressures will result from surcharge loads from floor slabs or pavements for parking that are located immediately adjacent to the walls. The surcharge-induced lateral earth pressures are uniform over the depth of the wall. Surcharge-induced lateral pressures for the "active" case may be calculated by multiplying the applied vertical pressure (in psf) by the active earth pressure coefficient (Ka). The value of Ka may be taken as 0.33. The surcharge-induced lateral pressures for the "at-rest" case are similarly calculated using an at-rest earth pressure coefficient (Ko) of 0.5. 1701rpt 10 S&EE 5.5 SITE PREPARATION AND STRUCTURAL FILL We recommend that areas of proposed building and pavement be stripped of asphalt. All existing underground utilities should also be removed. After stripping and excavation, subgrades of slabs, pavement, or areas to receive new fill should be thoroughly proof-rolled using heavy construction equipment. If the subgrade is wet and proof rolling is not feasible, the area should be probed using a steel bar so as to avoid disturbance and rutting of the subgrade soils. Areas which are found to be loose or soft, or which contain organic soils should be over-excavated. It is our experience that very soft subgrade can be stabilized with 2- foot of over-excavation and backfill with structural fill over a layer of geotextile. A geotechnical engineer/site inspector from our office should observe the proof-rolling and/or perform probing to assist in evaluating the over-excavation and backfill requirements. After stripping, over-excavation and excavation to the design grade, the top 12 inches of the subgrade soil should be moisture-conditioned to +/-2% from it optimum moisture content and then re-compacted to a firm and non-yielding condition or at least 95% of their maximum dry density as determined using ASTM D-1557 test procedures (Modified Proctor test). Structural fill should be used for all fill or backfill. The Structural fill materials should meet both the material and compaction requirements presented below. Material Requirements: Structural fill should be free of organic and frozen material and should consist of hard durable particles, such as sand, gravel, or quarry-processed stone. The onsite granular fill soils above the depth of 5 feet are suitable on a select basis. The native soils below are silty in nature and should not be used. Suitable imported structural fill materials include silty sand, sand, mixture of sand and gravel, recycled concrete, and crushed rock. All structural fill materials should be approved by a site inspector from our office prior to use. Placement and Compaction Requirements: Structural fill should be moisture-conditioned to +/- 2% from optimum prior to placement. The material should then be placed in loose horizontal lifts not exceeding a thickness of 6 to 12 inches, depending on the material type and compaction equipment. Structural fill should be compacted to a firm and non-yielding condition, or at least 95% of the maximum dry density as determined using the ASTM D-1557 test procedures. 1701rpt 11 S&EE 5.6 SLAB-ON-GRADE We recommend that the lab-on-grade be designed using a subgrade reaction modulus of 150 pounds per cubic inches (pci), and the subgrade be prepared in according to recommendations presented above. In order to minimize differential settlement, we recommend that the slab be underlain by 12 inches thick base course over a layer of geotextile. The base course should be 1-1/4” minus crushed rock, placed in two lifts and each lift compacted to a firm and non-yielding condition using a vibratory plate compactor that weighs at least 1,000 pounds. The compactor must make 4 passes (back and forth is one pass) in one direction, then 4 passes in a perpendicular direction. The geotextile should be woven with a minimum 200 pounds grab tensile strength of 200 pounds. The geotextile should be installed flat with all wrinkles removed and have 12 inches overlap. 5.7 PAVEMENT DESIGN RECOMMENDATIONS Pavement subgrade should be prepared according to procedures stated in Section 5.5. We recommend that asphalt pavements be designed with a California Bearing Ratio of 12, and rigid pavements be designed with a subgrade reaction modulus of 100 pci (pounds per cubic inch). The pavements should also be designed for frost protection consisting of at least 15 inches of pavement, base course, and/or granular subbase between the subgrade soils and the top of the pavement. The base course and granular subbase should be non-frost-susceptible and contain no more than 5 percent fines (material finer than a No. 200 U.S. standard sieve). Base course under pavements should consist of well-graded crushed rock. conforming to WSDOT specifications for Crushed Surfacing, Specification 9-03.9(3). Both the subbase and base course layers should be compacted to a firm and non-yielding condition or at least 95 percent of the maximum dry density, as determined by the modified Proctor compaction test (ASTM D 1557). A typical standard-duty (lightweight) pavement section that we have used on similar projects consists of 2.5 inches of Class B asphalt, 4 inches of base course, and 4 inches of subbase. A heavy-duty pavement section could consist of 4.5 inches of Class B asphalt, 6 inches of base course, and 6 inches of subbase. A concrete pavement section could consist of 6 inches of reinforced concrete over 4 inches of base course. Sidewalks could consist of 4 inches of Portland cement concrete over 4 inches of base course. We recommend that these typical sections be considered for planning purposes and that project-specific pavement design analyses be performed. These analyses will require traffic load data such as vehicle axle loads and daily vehicle trips. 1701rpt 12 S&EE 5.8 ADDITIONAL SERVICES We recommend the following our additional services during the construction of the project. 1. Monitor site preparation. We will observe proof-rolling and provide recommendations regarding local over-excavation to remove soft, wet or organic soil; observe and approve compaction of subgrade soils. 2. Observe and approve structural fill materials and base course; observe and approve fill placement and compaction; assist contractor in achieving required compaction. 3. Monitor underground utility construction. We will observe excavation and recommend re-use of onsite soil for backfill; observe excavation subgrade and provide recommendations regarding subgrade stabilization; observe dewatering and provide recommendations when necessary; observe any potential adverse impacts on nearby structures and provide recommendations regarding mitigation; observe backfill placement and assist contractor in achieving required compaction. 4. Monitor augercast pile installation. We will observe and approve contractor’s equipment; monitor and approve each pile installed. 5. Review contractors’ submittals and RFI’s. 6. Attend construction progress meetings. 7. Prepare and distribute field reports. 8. Other geotechnical issues deemed necessary. 6.0 CLOSURE The recommendations presented in this report are provided for design purposes and are based on soil conditions disclosed by the available geotechnical boring data. Subsurface information presented herein does not constitute a direct or implied warranty that the soil conditions between exploration locations can be directly interpolated or extrapolated or that subsurface conditions and soil variations different from those disclosed by the explorations will not be revealed. The recommendations outlined in this report are based on the assumption that the development plan is consistent with the description provided in this report. If the development plan is changed or subsurface conditions different from those disclosed by the exploration are observed during construction, we should be advised at once so that we can review these conditions, and if necessary, reconsider our design recommendations. 3/3/2017 900 Oakesdale Ave SW - Google Maps https://www.google.com/maps/place/900+Oakesdale+Ave+SW,+Renton,+WA+98057/@47.4698424,-122.1884064,11.97z/data=!4m5!3m4!1s0x549042cb6cbe1215:0x144adf08666e7253!8m2!3d47.4715883!4d-122.2337654 1/2 Map data ©2017 Google 1 mi 900 Oakesdale Ave SW buffalodesign architecture | interiors1520 fourth ave suite 400 seattle wa 98101 206 467 6306 | buffalodesign.com11/30/20161" =30'-0"oaksdale ave sw010204080160 ftremove planter & (4)trees for relocated firelaneexisting parking: 354 spacesprovided parking: 324 spacessecure yardsecure parkingfence & gate(5) secure parking spacesschematic designking county regional AFIS - site plan Figure 4 Job No. 1701 S&EE APPENDIX A FIELD EXPLORATION, LOG, AND SOIL CLASSIFICATION CHART One soil test borings, B-1 and B-2, were performed for the project. The boring locations are shown in Figure 2. The borings were advanced using a hollow-stem auger. Soil samples were taken during the drilling of soil test borings in general accordance with ASTM D-1586, "Standard Method for Penetration Test and Split-Barrel Sampling of Soils" (1.4” I.D. sampler). The penetration test involves driving the samplers 18 inches into the ground at the bottom of the borehole with a 140 pounds hammer dropping 30 inches. The numbers of blows needed for the samplers to penetrate each 6 inches are recorded and are presented on the boring logs. The sum of the number of blows required for the second and third 6 inches of penetration is termed "standard penetration resistance" or the "N-value". In cases where 50 blows are insufficient to advance it through a 6 inches interval the penetration after 50 blows is recorded. The blow count provides an indication of the density of the subsoil, and it is used in many empirical geotechnical engineering formulae. The following table provides a general correlation of blow count with density and consistency. DENSITY (GRANULAR SOILS) CONSISTENCY (FINE-GRAINED SOILS) N-value < 4 very loose N-value < 2 very soft 5-10 loose 3-4 soft 11-30 medium dense 5-8 medium stiff 31-50 dense 9-15 stiff >50 very dense 16-30 very stiff >30 hard A chart showing the Unified Soil Classification System is included at the end of this appendix One Shelby-tube sample was retrieved from depths of 11.5 to 14 feet at Boring B-2. The sample was transported to our soil laboratory for consolidation test. The test results are included in Appendix B. After drilling, the boreholes were backfilled with bentonite chips, and the surfaces were patched with cold- mix asphalt. APPENDIX B LABORATORY TEST RESULTS Project:1701 Date Received:February 2, 2017 Project #:17T-009 Sampled By:Client Client:Soil & Environmental Engineering Date Tested:February 13, 2017 Source:Sample 1, 11.5 ft Tested By:H Benny Sample #:T17-0258 Comments: Reviewed by: Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Corporate Office ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional offices in Olympia, Bellingham, and Silverdale All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval. Consolidation testing was performed on a GeoTac, Inc. automated consolidation test system. Preliminary data reduction is performed by the proprietary software that runs the test. Additional data reduction is performed by MTC personnel using this data. 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 10 100 1000 10000 100000 Strain - % Stress, psf Vertical Strain versus Stress Project:1701 Date Received: Project #:17T-009 Sampled By:Client Client:Soil & Environmental Engineering Date Tested:13-Feb-17 Source:Sample 1, 11.5 ft Tested By:H Benny Sample #:T17-0258 Comments: Reviewed by: Corporate Office ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional offices in Olympia, Bellingham, and Silverdale Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval. Consolidation testing was performed on a GeoTac, Inc. automated consolidation test system. Preliminary data reduction is performed by the proprietary software that runs the test. Additional data reduction is performed by MTC personnel using this data. February 2, 2017 0.90 1.00 1.10 1.20 1.30 1.40 1.50 10 100 1000 10000 100000Void Ratio Stress, psf Project:1701 Date Received: Project #:17T-009 Sampled By:Client Client:Soil & Environmental Engineering Date Tested: Source:Sample 1, 11.5 ft Tested By:H Benny Sample #:T17-0258 125 0.66 1.42 3.42 0.12 250 1.64 1.38 1.00 0.39 500 2.24 1.36 1.08 0.36 1000 3.25 1.33 0.16 2.37 2000 4.83 1.29 0.61 0.60 4000 6.92 1.23 0.64 0.56 8000 9.51 1.16 0.09 3.75 16000 13.01 1.07 0.11 2.87 32000 16.90 0.96 0.10 2.83 8000 16.39 0.98 2000 15.61 1.00 500 14.76 1.02 125 14.19 1.04 Initial Final Moisture Content, %48.1 39.4 Wet Density, pcf 101.3 113.1 Dry Density, pcf 68.4 81.2 Comments: Reviewed by: Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Corporate Office ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional offices in Olympia, Bellingham, and Silverdale Visit our website: www.mtc-inc.net Load, psf Strain Void Ratio t50, min Cv, ft2/day Test Summary February 2, 2017 February 13, 2017 All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval. Consolidation testing was performed on a GeoTac, Inc. automated consolidation test system. Preliminary data reduction is performed by the proprietary software that runs the test. Additional data reduction is performed by MTC personnel using this data.