Loading...
HomeMy WebLinkAboutSWP272845(1) i V, Jt1N � ' r 2r-1�9� r Report -Geotechnical Engineering Services Planned Additions and Improvements to _ �\ Tiffany Park Elementary School / Renton, Washington / June 18, 1999 �. f. i For Renton School District No. 403 �l J, r' GeoEngine Y File N. APPENDIX J Geo G Engineers ' June 18, 1999 Consulting Engineers and Geoscientists Offices in Washington, Renton School District No. 403 Oregon,and Alaska ' 1220 North 4th Street Renton,Washington 98055 ' Attention: Mike Torgerson We are pleased to present four copies of our"Report, Geotechnical Engineering Services, Planned Additions and Improvements to Tiffany Park Elementary School, Renton,Washington." Our services were completed in general accordance with the scope of services presented in our proposal dated April 7, 1999. Our services were formally authorized by you on May 4, 1999. ' The project was in the preliminary design phase at the time this report was prepared and final building loads are not available. We recommend that additional geotechnical evaluation be completed after building loads have been determined to assess the potential impacts of building ' settlement where foundations are supported above the compressible silt and clay encountered in our explorations. We appreciate the opportunity to be of service to you on this project. Please call us if you have any questions regarding the contents of this report or when we may be of further assistance. ' Yours very truly, GeoEngineers, Ind. ' B McFadden, P.E. - sociate JJM:ja:pb ' P:\2074004\00\fmals\207400400r.doc 1 GeoEngineers,Inc. Plaza 600 Building 600 Stewart St.,Suite 1215 Seattle,WA 98101 Telephone(206)728.2674 Fax(206)728.2732 ' wwtiegeoengineers.com CONTENTS ' Page No. ' INTRODUCTION.........................................................................................................................1 SCOPE.......................................................................................................................................1 PHASE 1 —GEOTECHNICAL DESIGN SERVICES 2 PHASE 2—GEOTECHNICAL SUPPORT DURING DESIGN 3 SITEDESCRIPTION...................................................................................................................3 ' SURFACE CONDITIONS 3 SUBSURFACE CONDITIONS 3 General 3 ' General Geology 4 Soil Conditions 4 Ground Water Conditions 6 ' CONCLUSIONS AND RECOMMENDATIONS ............................................................................6 GENERAL 6 SITE PREPARATION AND EARTHWORK 7 ' Demolition 7 Clearing and Site Preparation 7 Sedimentation and Erosion Control 9 Structural Fill 9 Open Cut Excavations 10 Permanent Cut and Fill Slopes 10 FOUNDATION SUPPORT 11 LATERAL RESISTANCE 12 FLOOR SLAB SUPPORT 12 RETAINING WALLS 12 PAVEMENT DESIGN 13 SEISMICITY 14 General 14 Uniform Building Code (UBC) Site Coefficient 14 Design Earthquake Levels 14 Liquefaction Potential 14 DRAINAGE CONSIDERATIONS 15 LIMITATIONS ' ...........................................................................................................................15 ' Figures Figure No. Vicinity Map 1 2 Site Plan ' G e o E n g i n e e r s 1 He No.2074-004-00-1130\061899 ' CONTENTS (CONT.) ' Pace No. APPENDIXA FIELD EXPLORATIONS...................................................................................A-1 APPENDIX A FIGURES Fissure No. ' SOIL CLASSIFICATION SYSTEM A-1 KEY TO BORING LOG SYMBOLS A-2 LOG OF BORING A-3...A-14 APPENDIX B LABORATORY TESTING................................................................................. B-1 GENERAL B-1 VISUAL CLASSIFICATIONS B-1 MOISTURE CONTENT DETERMINATIONS B-1 DRY DENSITY DETERMINATIONS B-1 ' PARTICAL SIZE ANALYSIS B-1 ATTERBERG LIMITS B-2 CONSOLIDATION TESTS B-2 ' APPENDIX B FIGURES Fissure No. SIEVE ANALYSIS RESULTS B-1 ATTERBERG LIMITS TEST RESULTS B-2 CONSOLIDATION TEST RESULTS B-3...B-4 ' G e o E n g i n e e r s II File No.2074-004-00-1130\061899 ' REPORT GEOTECHNICAL ENGINEERING SERVICES ' PLANNED ADDITIONS AND IMPROVEMENTS TO TIFFANY PARK ELEMENTARY SCHOOL RENTON, WASHINGTON ' FOR RENTON SCHOOL DISTRICT NO. 403 ' INTRODUCTION This report presents the results of our. geotechnical engineering services for the planned additions and improvements to the Tiffany Park Elementary School located along Lake Youngs Way Southeast in Renton,Washington. The site location is shown on the Vicinity Map,Figure 1. We understand that the project includes demolition of all existing structures with the exception of the classroom building located on the southwest portion of the property. The project was in the preliminary design phase at the time this report was prepared. However, a recent conceptual schematic design for a new site layout indicates that new buildings may include ' classrooms added to the northwest end of the existing classroom building (finish floor at about Elevation 372.5 feet) that will remain and a new multi-purpose building containing a gym, commons area, music room, and classrooms (finish floor at about Elevation 374.5 to 376.5 feet). ' Final foundation loads are not known at this time. We understand however, that exterior wall loads will be about 1,500 pounds per linear foot and that columns can be supported on footings ' proportioned for a 2,000 pound per square foot(psf) bearing pressure. In addition, improvements will include a new covered play area in the west portion of the site, ball fields on the northwest portion of the property, and at-grade parking areas north and east of the proposed buildings. ' Existing and proposed site improvements are shown on the Site Plan, Figure 2. Most of the improvements and construction will be at or near existing grades. However, cuts ' on the order of about 15 feet deep will be required east of the proposed new Multi-purpose Building and up to 7 feet deep in the northwest portion of the site for the ball fields. Most of the proposed parking and access road areas will be within a couple of feet of existing site grades, except for the access road from the east parking lot to the north parking lot where cuts on the order of about 10 feet are planned. ' SCOPE The purpose of our geotechnical engineering services is to evaluate the subsurface soil and ground water conditions as a basis for providing geotechnical recommendations regarding the ' proposed additions, new buildings and improvements at the Tiffany Park Elementary School. In our proposal we provided scopes of work and costs for three phases or work including our initial ' investigation and geotechnical design services (Phase 1), support during the design phase (Phase 2), and for geotechnical construction services (Phase 3). Phases 1 and 2 were approved at this time and our services for these two phases includes the following tasks: G e o E n g i n e e r s )< File No. 2074-004-00-1130\061899 ' PHASE 1 — GEOTECHNICAL DESIGN SERVICES Complete a field exploration program consisting of shallow borings using track-mounted ' hollow-stem auger drilling equipment. Obtained soil samples at about 5-foot intervals for laboratory testing to determine soil strength and settlement characteristics, where appropriate. ' Our specific scope of services includes the following tasks: 1. Review available geologic and subsurface information for the site. 2. Explore subsurface conditions at the site by drilling 12 borings using a track-mounted drill rig ' (rubber cleats) advancing hollow stem augers. The borings were advanced between 9 and 23.5 feet below the ground surface(bgs). 3. Evaluate the physical and engineering characteristics of the soils based on laboratory tests performed on samples obtained from the explorations. The laboratory tests consist of particle size and plasticity tests, moisture content and density determinations, and consolidations tests. 4. Provide recommendations for the following: a. Site preparation and earthwork including clearing criteria, suitability of on-site soils for use as structural fill, constraints for wet weather construction, gradation criteria for any structural fill material which may have to be imported, and structural fill placement and compaction requirements. b. Temporary and permanent cut and/or fill slopes. c. Provide recommendations for sedimentation and erosion control during and following construction, and permanent site drainage. d. Develop recommendations for foundation support including allowable soil bearing ' pressures, settlement estimates, minimum footing sizes for pad and strip footings, and minimum depth of footings below finished grade. e. Allowable increases in soil bearing when supporting seismic generated loads. f. Active and passive soil pressures for design of foundations and walls. g. Coefficient of base friction for resisting lateral forces. h. Provide recommendations for support of on-grade floor slabs including capillary break and vapor retarder as appropriate. i. Discuss seismicity at the site and provide seismic design-parameters including soil profile ' type and site coefficient based on 1997 Uniform Building Code(UBC) criteria. j. Design pavement sections for access driveways and parking areas. ' k. Provide recommendations for surface and subsurface drainage based on ground water conditions encountered in the explorations or expected in the area. Discuss geotechnical considerations related to groundwater and seepage conditions including anticipated seasonal fluctuations. 1. Comment on any anticipated construction difficulties identified from the results of our ' site studies and from our experience on projects at similar sites. 5. Prepare a written report presenting our conclusions and recommendations together with supporting field and laboratory information for incorporation into design of the project. ' G e o E n g i n e e r s 2 File No. 2074-004-00-1130\061899 PHASE 2— GEOTECHNICAL SUPPORT DURING DESIGN ' During and after our geotechnical report has been submitted, we will provide design support including consultation for alternative design approaches for elements such as retaining walls and detention facilities, geotechnical design criteria for specification preparation, plan and specification review, and attending design meetings. ' SITE DESCRIPTION SURFACE CONDITIONS We reviewed information provided by McGranahan Partnership that included an existing site survey map prepared by D.A. Berg, Inc., dated April 28, 1999 and a schematic drawing showing a conceptual site layout for the proposed improvements prepared by Weisman Design Group, dated April 20, 1999. Our Site Plan (Figure 2) shows the existing features with the proposed ' (most recent) layout of improvements superimposed on the plan. Tiffany. Park Elementary School is located at 1601 Lake Youngs Way SE, west of the intersection of Lake Youngs Way and Kirkland Avenue SE. The approximately 10-acre site is ' presently occupied by the existing Tiffany Park Elementary School. The site is bordered to the north and east by Lake Youngs Way SE and by residential developments to the south and west. ' The school site is situated on a glacial till upland above the Cedar River valley, about 3,000 feet south of the Cedar River and State Route 169. The ground surface generally slopes down to the west portion of the site from the north and from the east. The ground surface elevations range from about 372 to 377 feet in the central and south portions of the site where the existing buildings are located. The ground surface in the north portion of the site slopes up to the ' north to about Elevation 382 feet,while the ground surface in the east portion of the site slopes up to the east to about Elevation 390 feet. The lowest area on the site is along the west property line ' at about Elevation 368 feet. Three buildings and a covered play area occupy the central and south portions of the site with the newest building located along the southwest property line. Asphalt paved parking areas and ' access roads are located on the southeast side of the property. A portable classroom building is located northwest of the main classroom building. The buildings are typically surrounded by asphalt or concrete surfaces. The north and west portions of the site are covered with lawn and occupied by several conifer and deciduous trees. The east to northeast portions of the site are forested with numerous large conifer and deciduous trees. The locations of surface features are ' shown in Figure 2. SUBSURFACE CONDITIONS ' General We explored subsurface soil and groundwater conditions at the site by drilling twelve borings to depths ranging from about 9 to 23.5 feet bgs. Holt Drilling Inc. of Puyallup, Washington completed the borings on May 5 and 6, 1999 using track-mounted hollow-stem auger drilling equipment. The locations of the borings are shown in Figure 2. The details of our field G e o E n g i n e e r s 3 Re No. 2074-004-00-1130\061999 ' exploration program and exploration logs are presented in Appendix A. Our laboratory testing program is summarized in Appendix B. General Geology The project site is located along the edge of a glacial till upland, south of the Cedar River ' Valley. Based on the Geologic map of the Renton Quadrangle, King County, Washington, (Mullineaux, 1965), glacial ground moraine deposits consisting of ablation till over lodgment till exists at relatively shallow depths in and around the school property. Lodgment till in the area is ' generally a compact, unsorted mixture of silt, clay, sand,and gravel. The overlying ablation till is generally thin (2 to 10 feet thick) and much less compact. ' Three areas were identified on the map as having localized lacustrine deposits around the site and one appears to be on or adjacent to the north side of the school property. Mapped lacustrine deposits are described as typically consisting of mixtures of silt, clay, and peat. Lacustrine deposits are susceptible to consolidation settlement. ' Soil Conditions In general,the subsurface soil conditions vary across the site, but are relatively uniform in the proposed building area near the center of the site. For the purpose of describing the soil conditions at the site, subsurface conditions under the major new improvements are described separately below. Proposed Multi-Use Building: Borings B4 through B-9 were drilled in accessible areas ' around the proposed Multi-use Building near the middle of the site. In general, all the borings, except B-9, encountered similar soil conditions where soft to stiff lacustrine deposits consisting of silt and clay were encountered over medium dense to very dense or hard glacial deposits. Boring B-9, drilled at the north end of the proposed building, encountered about 10 feet of medium dense silty sand fill soils over very dense glacial till. ' The soft to stiff lacustrine deposits ranged from depths of about 10 to 16 feet bgs. On the southwest side of the main classroom building the lacustrine deposits were encountered to depths ' of 10 to 12 feet in borings B4 and B-5, and on the east side they were encountered from depths of 11.5 to 16 feet in borings B-6 through B-8. The lacustrine deposits generally consist of compressible, soft to stiff, silt and elastic silt with occasional layers of silty sand or poorly graded ' sand. Approximately 6 to 7 feet of soft to medium stiff lean clay was encountered in the upper portion of boring B4. The soils in the upper 5 to 7 feet of each boring had the appearance of fill due to observed mixed soil conditions. Tree roots were encountered to a depth of about 10.5 feet in boring B-8. Medium dense to very dense sand deposits or glacial till soils underlie the lacustrine deposits ' encountered in the borings. The sandy soils generally consist of medium dense to very dense silty sand or poorly graded sand. The glacial till generally consists of very dense silty sand with gravel. Boring B-7 encountered hard laminated silt with fine sand that appeared to be siltstone about 15 feet bgs. ' 0 e o E n g i n e e r s 4 File No. 2074-004-00-1130\A61899 The ground surface elevations vary significantly around the proposed building area with asphalt and concrete surfaces, lawn, and forested areas. The asphalt encountered in the borings around the existing buildings was generally 2 to 3 inches thick and overlies about 3 to 4 inches of base material. The lawn or sod areas were generally about 3 inches thick. Forest duff was encountered in boring B-8, but it was only about 1-inch thick. Proposed Classroom Addition: Boring B-2 was drilled to a depth of about 23.5 feet in the area where the classroom addition is proposed on the northwest side of the existing classroom ' building. Approximately 3 inches of sod was encountered at the ground surface. Approximately 4 feet of medium stiff, compressible, organic silt was encountered below the sod overlying about ' 4 feet of medium dense silty sand fill,which in turn overlie a 5-foot thick stiff silt layer. Medium dense silty sand was encountered from a depth of about 13 to 17 feet overlying very dense silty sand with gravel at depth. Proposed Covered Play Area: Boring B-3 was drilled to a depth of about 11 feet at the location of the proposed covered play area. Approximately 6 inches of sod was encountered at the ground surface. Approximately 3.5 feet of compressible organic silt with scattered wood debris was encountered below the sod overlying about 2.5 feet of medium stiff to stiff silt. Compressible, stiff, lean clay was encountered from a depth of 6 to 10 feet bgs. At a depth of 10 feet deep,very dense glacial till composed of silty sand with gravel was encountered. Proposed Parking Areas: The two main proposed parking areas are located northeast and south of the proposed Multi-use Building. The south parking area is where bus parking and bus ' traffic will occur,while the northeast parking area will be for general parking. Borings B-1, B-6 and B-7 were drilled in the area near the south parking lot. Boring B-1 was ' drilled through the existing parking surface and encountered about 6 inches of asphalt over 2 inches of base material. Underlying the pavement materials, soft silt fill was encountered to a depth of about 3 feet overlying a soft to medium stiff, compressible organic silt layer that extended down to a depth of about 4.5 feet bgs. Stiff silt was encountered to the bottom of the boring at a depth of about 11.5 feet. A wet sand layer about 12 inches thick was encountered in t the silt. Borings B-6 and B-7 encountered 13.5 and 11.5 feet, respectively, of fill and lacustrine deposits over denser glacial soils. The upper 4 feet of B-6 and the upper 7 feet of B-7 appeared to be fill soils consisting of medium stiff silt or dense mixed silty sand and silt. ' Borings B-10 and B-11 were drilled in the area around the proposed northeast parking lot. Three to four inches of sod was encountered at the ground surface in borings B-10 and B-11. Boring B-10 encountered about 2.5 feet of medium dense silty sand.fill overlying dense soils. Boring B-11 encountered about 4.5 feet of silty sand fill overlying lacustrine deposits consisting of medium stiff silt and loose silty sand to the bottom of the boring at a depth of 14 feet. ' Boring B-8 was drilled near the location where a road cut will be made to access the northeast parking lot. Soils encountered in B-8 include 5 feet of fill soils composed of 2 feet of organic silt overlying 3 feet of elastic silt overlying compressible, medium stiff, lacustrine silt that was encountered to a depth of about 12 feet. Loose silty sand was encountered below the lacustrine 1 G e o E n g i n e e r s 5 He No. 2074-004-00-1130\061899 - i i depth of about 17 feet overlying stiff to very stiff silt. The underlying silt layer was silt to a dep y1 g ry _ encountered to the bottom of the boring at a depth of about 21.5 feet. iMulti-Use Turf Field and Baseball Field. Boring B-12 was drilled on the slope to the north of the proposed fields. Boring B-12 encountered about 3 feet of compressible organic silt i overlying about 3 feet of medium dense sandy silt. Medium dense to very dense silty sand soils were encountered below a depth of about 6 feet. i Ground Water Conditions We observed ground water seepage in five of the borings (B-1, B4, B-5, B-7, and B-8) drilled at the site, and moist to wet soil layers in three other borings (B-2, B-11, and B-12). No ground water seepage or wet soils were observed in the other borings. Based on our explorations, ground water seepage appears to be present within sandy layers i within the lacustrine deposits and more commonly in sandy layers located below the lacustrine deposits and over the dense, less permeable glacial till soils. Ground water seepage is also present as perched water on top of the shallow low permeability silts as evident by wet surface ' conditions in the north portion of the site. Borings B4, B-5, B-7, and B-8 encountered ground water seepage at depths of 13, 8.5, 11.5, and 12.5 feet bgs, respectively, within sandy layers i underlying the softer lacustrine deposits, but overlying very dense till or hard silt. Boring B-1 encountered ground water at a depth of 9.5 feet in a sand layer within the lacustrine deposits. Moist to wet soils were observed in a silty sand layer in B-2 at a depth of about 9.5 feet, in B-11 iin silt and silty sand between depths of about 4 and 9 feet, and in B-12 in a silty sand layer from a depth of about 6 to 7 feet. i Ground water levels at the site should be expected to fluctuate as a function of seasonal precipitation, and other factors. We expect that the ground water seepage levels observed in the sandy layers above the glacial till across the site are likely near their highest levels. This iexpectation is based on the time of year our explorations were completed and the amount of precipitation received in the Puget Sound region this past winter. We also expect that wet ground i surface conditions will persist in areas where low permeability silt underlies the sod and restricts infiltration of rain and irrigation water. ' CONCLUSIONS AND RECOMMENDATIONS GENERAL Based on the results of our explorations, laboratory testing and engineering analyses, we iconclude that the site can be satisfactorily developed and the building supported on shallow foundations, as proposed. However, special consideration must be given to building foundation i and floor slab support for the two buildings because compressible soil is present at shallow depths in the building area. Compressible silt, clay, and organic silt extending from near the ground surface to 13.5 feet ior more below the exiting ground surface is present under the proposed building areas. The silt and clay will compress under foundation and floor slab loads in the building area and to a lesser idegree below paved roadway and parking areas depending on final site grades. Long-term iG e o E n g i n e e r s 6 File No. 2074-004-00-1130\061899 secondary compression of the organic silt which was encountered at relatively shallow depths will occur over the life of the structure and is more difficult to predict. We therefore recommend ' that the compressible organic silt be removed when encountered in footing areas and be replaced with structural fill. Because the compressible silt and clay soils extend to depths up to 14 feet, we ' recommend that a 2-foot thickness of the compressible soils be removed from footing areas and replaced with structural fill to reduce the risk of unacceptable magnitudes of post-construction settlement. The near surface on-site soils include silt, organic silt, elastic silt and lean clay that are very moisture sensitive and will be difficult to operate heavy equipment on in all but the driest ' weather. It will also be very difficult to achieve adequate compaction with these soils to allow their use as structural fill due to their fine-grained composition and high in-situ moisture contents. Therefore, we recommend that you plan to use clean imported granular structural fill for all building pad, roadway and parking area fill. It will be necessary to import fill for use in much of the utility trench backfill to replace the unsuitable silt and organic silt when encountered within ' these areas. It may be possible to selectively use the most suitable on site soils for use when grading the ball field areas. However, due to the high moisture content of the soils, discing and aeration of ' the soils will be needed to dry them sufficiently to achieve proper compaction. The following sections of this report present our conclusions and recommendations for site development, foundation support and performance estimates of the proposed structure. i SITE PREPARATION AND EARTHWORK ' Demolition At this time we understand that the only building that will remain is the newer classroom building on the southwest portion of the site. We recommend that all building foundations, septic systems, utilities, pavements and other improvements associated with the existing structures be removed from within the proposed building and pavement areas. Any depressions created by the removal of these facilities should be cleaned free of loose material and filled with structural fill ' compacted as described in a subsequent section of this report. If not removed from the site, we recommend that abandoned utilities around the proposed building pads be grouted full to prevent potential unwanted migration of water or collapse. This would include abandoned storm, sewer, sanitary sewer, and water lines 6 inches or greater in diameter. ' Clearing and Site Preparation We recommend that proposed pavement and building areas be stripped of all existing ' vegetation, sod and root systems. We recommend that trees, stumps, brush, sod, debris, and topsoil be cleared from the proposed building and pavement areas,and areas that will receive new fills. The topsoil materials can be separated and stockpiled for use in areas to be landscaped. ' Debris should be removed from the site, but organic materials could be chipped/composted and also reused in landscape areas, if desired. Based on our explorations, the depth of stripping required will generally be on the order of 6 inches. 0 e o E n g i n e e r s 7 File No. 2074-004-00-1130\061999 i iIt may be difficult to operate heavy equipment on the site because of the lacustrine silt/clay deposits that will be exposed at the surface after stripping. We recommend that wide track dozers ibe used to complete much of the site stripping to avoid significant disturbance of the underlying soil if it is to remain in place. If the stripping operations cause disturbance of the underlying soil, additional excavation may be necessary. Disturbance of the shallow subgrade soils should be i expected if site preparation work is done during periods of wet weather or when the subgrade soils are still wet from seasonal rainfall. We therefore recommend site grading take place during ithe drier summer months (July through September) to reduce grading costs. Material from the stripping operations should be sent off site for disposal or used for landscaping purposes. We also recommend that the lacustrine deposits exposed at subgrade elevation in pavement areas be disced to aerate and dry the soil prior to compacting it to a firm unyielding condition. The site should be graded to a slightly crowned surface once stripping has been completed. iThis grading should be done to enhance drainage from the site and proposed building areas, and to prevent ponding of water in areas to receive any additional fill. The exposed subgrades in building, roadway and parking areas should be evaluated as the site igrading is completed in each area. Proofrolling with heavy rubber-tired construction equipment should be used for this purpose, if practicable. The site should be proofrolled only after an i extended period (at least two weeks) of dry weather. Probing should be used to evaluate the subgrade during periods of wet weather or when the subgrade soils are more than two or three percent wetter than their optimum moisture content. Any soft areas noted during iproofrolling or probing should be excavated and replaced with compacted structural fill. We recommend that exposed subgrade in walkway areas be evaluated by probing, or by proofrolling i if practical. Once the subgrade in pavement areas has been prepared, all traffic except that required to place subsequent layers of material should be kept off the area until paving is completed. We irecommend that temporary roads and laydown areas be constructed to reduce the risk of disturbing the subgrade soils. Temporary roads should consist of 12 to 18 inches of quarry spalls or clean granular structural fill placed over geotextile fabric. The geotextile should be a woven fabric intended for soil separation and reinforcement within roadway embankments, such as Mirafi 50OX or Amoco2002. iThe recommended pavement sections presented in a subsequent section of this report is not intended to support heavy construction traffic. If all or any part of these pavement sections is i placed while building construction is still in progress, these areas should be barricaded and roped off to prevent vehicle access. This is to reduce the risk of softening of the subgrade, contamination of the subbase and base course materials soils, or pavement failure. The use of an iasphalt treated base (ATB) pavement section for temporary roadways is discussed below under "Pavement Design." 1 1 iG e o E a g i n e e r s 8 File No. 2074-004-00-1130\061899 ' Sedimentation and Erosion Control In our opinion, the erosion potential of the on-site soils is low to moderate because of the relatively flat site grades. Construction activities including stripping and grading will expose soils to the erosional effects of wind and water. The amount and potential impacts of erosion are ' partly related to the time of year that construction actually occurs. Wet weather construction will increase the amount and extent of erosion and potential sedimentation. Erosion and sedimentation control measures may be implemented by using a combination of ' interceptor swales, straw bale barriers, silt fences and straw mulch for temporary erosion protection of exposed soils. Existing storm water systems and off-site areas should be protected during construction to reduce the risk of sedimentation. All disturbed areas should be finish graded and seeded as soon as practical to reduce the risk of erosion. Erosion and sedimentation control measures should be installed and maintained in accordance with the requirements of the ' City of Renton. Structural Fill ' All new fills in building and pavement areas should be placed and compacted as structural fill. The suitability of soil for use as structural fill will depend on its gradation and moisture content. In our opinion, the lacustrine silt and clay soils encountered in our explorations should not be considered for use as structural fill. These soils and the silty sand and sandy silt soils cut from the slopes north of the ball fields and east of the existing buildings may be used as fill in the ball field areas provided that proper moisture conditioning and compaction are achieved. This will likely require discing and drying of the soils during warm, dry weather for acceptable placement and compaction. We recommend, therefore, that the project be planned to include ' importing structural fill to replace excavated soils in all utility trench excavations, and for achieving grade and replacing the compressible silt and organic silt removed from the proposed ' building areas. We recommend that all imported structural fill consist of sand and gravel containing less than 3 percent fines (material passing U.S. Standard No. 200 sieve) by weight relative to the fraction ' of the material passing the %-inch sieve. This material should be free of debris, organic contaminants and rock fragments larger than 3 inches. All structural fill placed to support foundations and floor slabs should be compacted to at least 95 percent of the maximum dry density (MDD), per ASTM D-1557. Pavement area fill, including utility trench backfill, should be compacted to at least 90 percent of MDD, except for the upper 2 feet below finished subgrade surface, which should be compacted to at least 95 percent of MDD. Structural fill to support walkways should be placed after the subgrade is ' evaluated as recommended above and be compacted to at least 90 percent of MDD. Fill placed in the ball field areas should be compacted to at least 90 percent of MDD. Structural fill should be placed in loose lifts not exceeding 8 inches in thickness. Each lift should be conditioned to the proper moisture content and compacted to the specified density before placing subsequent lifts. We recommend that a representative from our firm be present G e o E n g i n e e r s 9 He No. 2074-004-00-1130\061899 ' during P roofrolling and/or probing of the exposed subgrade soils in pavement areas and placement of structural fill. Our representative will evaluate the adequacy of the subgrade soils ' and identify areas needing further work, perform in-place moisture-density tests in the fill to determine if the compaction specifications are being met, and advise on any modifications to ' procedure which might be appropriate for the prevailing conditions. Open Cut Excavations ' The stability of open cut slopes is a function of soil type, ground water level, slope inclination, slope height and nearby surface loads. The use of inadequately designed open cuts could impact the stability of adjacent work areas, existing utilities, and endanger personnel. In our opinion, the contractor will be in the best position to observe subsurface conditions continuously throughout the construction process and to respond to variable soil and ground water conditions. Therefore, the contractor should have the primary responsibility for deciding whether or not to use open cut slopes rather than some form of temporary excavation support, and for establishing the safe inclination of the cut slope. All open cut slopes and temporary excavation support should be constructed or installed, and maintained in accordance with the requirements of the appropriate governmental agency. ' For planning purposes onlv, we recommend that temporary cut slopes be no steeper than 1.5H:1V (horizontal:vertical) in the existing fill or lacustrine deposits. Stable cut slopes in the compressible lacustrine silt, clay, and organic silt layers will be partially dependent on the time of ' year construction occurs and on ground water conditions. Depending on the ground water conditions during construction stable slopes in these soils could vary from about 1.5H:IV to 3H:1V. Acceptable slope inclinations should be determined during construction and should be in accordance with OSHA and WISHA guidelines. The above guidelines assume that surface loads such as equipment loads and storage loads twill be kept a sufficient distance away from the top of the cut so that the stability of the excavation is not affected. We recommend that this distance be not less than the depth of the cut. It should be expected that excavation faces will experience some sloughing and raveling. Berms, swales, or drainage ditches should be installed around the perimeter of each excavation to intercept surface runoff and reduce the potential for flow over the top of slopes. ' Some ground water seepage may be encountered in the excavations depending on the time of year. We expect that ditching and sump pumping during-construction will be sufficient to keep ' water from ponding in relatively shallow excavation. Permanent Cut and Fill Slopes We recommend that any permanent slopes constructed in the lacustrine deposits be constructed at 3H:1V, or flatter. Flatter slopes might be considered for ease of maintenance. Unprotected slopes will be subject to erosion until a protective vegetative cover is well established. Therefore, we recommend that any slope surfaces be planted as soon as practical to G e o E n g i n e e r a 10 He No. 2074-004-00-1130\061899 ' minimize the potential for erosion. A temporary covering, such as jute mesh, should be installed rru p P �' on the slopes as necessary until the vegetative cover has taken effect. ' Appropriate drainage measures, as described below in the "Drainage Considerations" section of this report, should be implemented to collect and control surface runoff and ground water ' seepage. FOUNDATION SUPPORT ' We recommend that the new buildings be supported on conventional spread footings bearing on a pad of structural fill. Exterior building footings should be supported on a pad of structural fill with a minimum thickness of 2 feet. Column footings should be supported on a pad of structural fill with a minimum thickness of 2 feet or one-half the footing width whichever is greater. The structural fill pad will provide more uniform bearing support than the existing soils ' and will reduce footing settlements. The zone of structural fill should extend laterally beyond the footing edges a horizontal distance at least equal to one-half the thickness of the fill. This method of support has proven successful on a large number of projects in similar soil conditions around the Puget Sound. To reduce the potential impacts of differential settlement where building footings extend into ' areas occupied by existing buildings, it may be necessary to increase the thickness of structural fill below the footings to transition into these areas that have been loaded by the existing structure. We recommend that additional evaluations be completed after final foundation loads ' have been determined. Depending on the results of the evaluations it may be necessary to completed additional explorations to determine the thickness of fill, is any, below the existing buildings. It may also be possible to develop additional recommendations for the structural fill thickness transition that can be verified by completing test pit explorations during construction within the areas of the existing buildings. ' We recommend that exterior footings be founded at least 18 inches below lowest adjacent finished grade. The top of interior footings should be founded a minimum of 12 inches below bottom of slab. The recommended allowable bearing pressure for footings supported as recommended is 2,000 psf. The allowable soil bearing pressure applies to the total of dead plus long-term live loads and may be increased by up to one-third for short-term live loads such as ' wind or seismic forces. We estimate that the total settlement of footings founded on structural fill overlying lacustrine deposits as described above, will be less than 1-inch and that post-construction settlement will be less than % inch. Post-construction differential settlement between equally loaded column footing or along a 25-foot section of continuous wall footing should be less than '/z-inch. We expect much of the footing settlements will occur as loads are applied. Loose or disturbed soils not removed from the footing excavation prior to placing concrete will result in additional settlement. We recommend that all footing excavations be evaluated by a representative of our firm immediately before any structural fill, mud mat, steel or concrete is placed, to evaluate if the 0 e o E n g i n e e r s 11 File No. 2074-004-00-1130\061899 work is being completed in accordance with our recommendations and that subsurface conditions are as expected. LATERAL RESISTANC E ' Lateral loads can be resisted by passive resistance on the sides of the footings and by friction on the base of the footings. Passive resistance should be evaluated using an equivalent fluid density of 300 pounds per cubic foot (pc fl where footings are surrounded by structural fill ' compacted to at least 95 percent of MDD, as recommended. Resistance to passive pressure should be calculated from the bottom of adjacent floor slabs and paving or below a depth of 2 feet where the adjacent area is unpaved, as appropriate. Frictional resistance can be evaluated using ' 0.4 for the coefficient of base friction against footings. The above values incorporate a factor of safety of about 1.5. FLOOR SLAB SUPPORT We recommend that floor slabs be supported on at least a 12-inch thickness of structural fill placed and compacted as recommended above in the"Site Preparation and Earthwork" section. If prevention of moisture migration through the slab is essential in the building, (i.e., in portions of ' the building areas where an adhesive will be used to attach tile or carpeting, for storage areas,and for enclosed areas), a vapor retarder such as plastic sheeting should be installed between the slab and the gravel base course. It may also be prudent to apply a sealer to the slab to further retard the migration of moisture through the floor. A 2-inch thick layer of fine to medium sand containing less than 3 percent fines may be placed over the vapor retarder to protect it during slab ' construction and to aid in uniform curing of the concrete. RETAINING WALLS ' Retaining walls that are typically not constrained from rotating outward should be designed fora lateral pressure based on an equivalent fluid density of 35 pounds per cubic foot (pef). Walls that are typically constrained from rotating outward, should be designed for a lateral ipressure based on an equivalent fluid density of 55 pcf. Heavy compaction equipment should not be operated adjacent to the walls within a distance equal to the height of the walls. The fill within ' this zone should be compacted with relatively light,hand-operated mechanical equipment. Positive drainage should be provided behind retaining walls by placing a zone of free draining sand and gravel (containing less than 3 percent fines for the fraction passing the 1/4-inch ' sieve) against the wall. This drainage zone should be at least 12 inches wide (measured horizontally) and extend along the entire height of the wall. Perforated pipe must be installed at ' the base of this drainage layer and be connected to tightlines that direct the flow to the storm drain or other suitable disposal point. Passive and frictional resistance acting on portions of the walls and footings should be evaluated as discussed above in the"Lateral Resistance"section of this report. G e o E n g i n e e r s 12 He No. 2074-00400-1130\061899 PAVEMENT DESIGN The exposed subgrade in pavement areas should be proofrolled or otherwise examined as ' discussed above in the "Site Preparation and Earthwork" section to detect areas of soft subgrade or unsuitable soils. This is especially important where the lacustrine deposits exist below the ' pavement areas. Soft or disturbed areas which develop in the subgrade should be removed and replaced with granular fill compacted as recommended to provide adequate pavement support. The thickness of additional sand and gravel fill required will depend upon the firmness of the subgrade at specific locations and should be evaluated during construction. We recommend that the pavement section in automobile parking areas consist of at least 2 inches of Class B asphalt concrete, 4 inches of clean crushed rock base, and 12 inches of ' subbase overlying a geotextile for soil separation and additional subgrade strength where compressible silt and clay are exposed at subgrade elevation. In roadway and bus ' loading/parking areas, the minimum thickness should be 4 inches of asphalt concrete, 6 inches of crushed rock base and 12 inches subbase over a geotextile. The subbase material should meet the requirements previously specified for gradation of structural fill. These pavement sections ' require that the subgrade is prepared as recommended and that pavement construction is done during a period of extended dry weather. ' The crushed rock base course and subbase should each be compacted to at least 95 percent of the maximum dry density determined in accordance with ASTM D 1557. It is important to pavement performance that backfill in utility trenches located in areas to be paved also be compacted as specified for structural fill. All new Class B asphalt concrete pavement materials and placement should generally conform to Section 5-04, Washington State Department of Transportation (WSDOT) 1998 Standard Specifications for Road, Bridge and Municipal Construction. Asphalt concrete should be compacted to at least 92 percent of Rice density. All crushed rock should conform to ' Section 9-03.9(3) of the Standard Specifications. The geotextile should be a woven fabric intended for soil separation and reinforcement in ' roadway embankments. Mirafi 50OX and Amoco 2002 are two such suitable geotextiles for this application. Similar geotextiles are available from other manufacturers. It may be desirable to place asphalt treated base (ATB) in place of the base course layers if permanent roadway alignments will be used for access during construction. This will be particularly important if building construction continues into the winter season and roadway and ' parking areas have not yet been paved. The ATB will, in conjunction with the subbase, provide a section less susceptible to damage than the base course and subbase layers only. We recommend that this alternative pavement section in automobile parking areas consist of ' at least 2 inches of Class B asphalt concrete, 4 inches of ATB and 8 inches of subbase overlying a geotextile where compressible silt and clay are exposed at subgrade elevation. In roadway and bus loading/parking areas, the minimum thickness' should be 3 inches of asphalt concrete, 6 inches of ATB and 10 inches of subbase overlying a geotextile. It is important to realize that some damage will likely occur to the ATB and subgrade during construction and repair may be ' G e o E n g i n e e r s 13 File No. 2074-004-00-1130\061899 necessary prior to final paving. Areas accessible to heavy construction traffic should be limited to prevent excessive damage to the ATB and subgrade. ' We recommend that the ATB be evaluated by proofrolling prior to placing final pavement. Soft areas observed during proof rolling should be removed and the subgrade repaired as recommended above under "Site Preparation and Earthwork." SEISMICITY ' General The Puget Sound, area is a seismically active region and has experienced thousands of earthquakes in historical time. However, only five to 20 of these are typically felt because the imajority of recorded earthquakes are smaller than Richter magnitude 3. Seismicity in this region is attributed primarily to the interaction between the Pacific, Juan de Fuca and North American plates. The Juan de Fuca plate is subducting beneath the North American Plate. Each year 1,000 to 2,000 earthquakes occur in Oregon and Washington. In recent years two large earthquakes occurred which resulted in some liquefaction in loose alluvial deposits and significant damage to some structures. The first earthquake, which was centered in the Olympia area, occurred in 1949 with a Richter magnitude of 7.1. The second earthquake,which occurred in 1965, was centered between Seattle and Tacoma and had a Richter magnitude of 6.5. ' Uniform Building Code (UBC) Site Coefficient The Puget Sound region is designated as a Seismic Zone 3 in the 1997 edition of the Uniform Building Code (UBC). For Zone 3 locations, a Seismic Zone Factor (Z) of 0.30 is applicable ' based on UBC Table 16-I. In our opinion, the soil profile at the site is best characterized as Type SD, based on UBC Table 16-J. Design Earthquake Levels The key seismic design parameters are the peak acceleration and the Richter magnitude of the earthquake. In general, a design earthquake is chosen based on the probability that the design earthquake will not be exceeded over a given time period. The level of seismicity recommended ' in the 1997 edition of the UBC for human occupancy buildings is an earthquake with a 10 percent probability of being exceeded in a 50-year period. The design earthquake event that corresponds to this probability is an earthquake with a Richter magnitude of 7.5 and a peak horizontal ground ' acceleration of approximately 0.3g. ' Liquefaction Potential Liquefaction is a condition where soils experience a rapid loss of internal strength as a consequence of strong ground shaking. Ground settlement, lateral spreading and/or sand boils ' may result from soil liquefaction. Structures supported on liquefiable soils can suffer foundation settlement or lateral movement during earthquakes that may be severely damaging -to 'the ' structures. ' G e o E n g i n e e r s 14 File No. 2074-00400-1130\061899 ' Conditions favorable to liquefaction occur in loose to medium dense, clean to moderately silty sand that is below the ground water table. Ground water was observed in five borings as ' discussed the "Ground Water Conditions" section of this report. Two of the borings (B4 and B-5) encountered ground water in dense soils that are not susceptible to liquefaction. Boring B-1 encountered a saturated approximately 1-foot thick sand layer about 9.5 feet below the existing ground surface. Boring B-7 encountered a saturated approximately 1.5-foot thick sand layer about 11.5 feet bgs. Boring B-8 encountered a saturated silty sand layer that was about 4 feet ' thick and located from about 12 to 16 feet below the existing ground surface. In our opinion, the saturated sand layers encountered in our explorations have a low to ' moderate susceptibility to liquefaction. Furthermore, it is our opinion that the potential settlement in these layers during strong ground shaking should be less than 1 inch. ' DRAINAGE CONSIDERATIONS We expect that shallow perched groundwater may be encountered during grading, and foundation and utility excavation. Ground water was encountered near the proposed subgrade ' elevation of cut areas to be located in the east portion of the site. We anticipate that this water can be temporarily handled during construction by ditching and pumping from sumps, as ' necessary. However, additional trenches and dewatering efforts may be necessary in portions of the site depending on ground water levels at the time of construction. All collected water should be safely routed to suitable discharge points. We recommend that perimeter footing drains be installed for all buildings. The perimeter drains should be installed at the base of the exterior footings. The perimeter drains should be ' provided with cleanouts and should consist of at least 4-inch-diameter perforated, smooth-walled polyvinyl chloride (PVC) pipe placed on a 3-inch bed of, and surrounded by 6 inches of drainage material enclosed in a non-woven geotextile to prevent fine soil from migrating into the drain ' material. The drainage material should consist of free-draining gravel containing less than 3 percent fines. The perimeter drains should be sloped to drain by gravity, if practicable, to a ' suitable discharge point, preferably a storm drain. Water collected in roof downspout lines must not be connected to the footing drain lines and should be routed to appropriate discharge points in separate pipe systems. All paved and landscaped areas should be graded so that surface drainage is directed away from the buildings to appropriate catch basins. ' LIMITATIONS We have prepared this report for use by Renton School District No. 403 and members of the ' design team for use in the design of the proposed improvements. The conclusions and recommendations in this report should be applied in their entirety. The data and report should be provided to prospective contractors for bidding or estimating purposes; but our report, ' conclusions and interpretations should not be construed as a warranty of the subsurface conditions. ' G e o E n g i n e e r s 15 He No. 2074-004-00-1130\061999 ' project was in the preliminary design e.at the time this report was prepared. We Thep �e p 1narY gn stag expect that additional consultation will be necessary during design development. Additional ' consultation is especially important for further evaluation of potential settlement and building performance. If there are any changes in the grades, location, configuration, loads or type of construction planned, the conclusions and recommendations presented in this report might not be fully applicable. If such changes are made, we should be engaged to review our conclusions and recommendations and to provide written modification or verification, as appropriate. When the tdesign is finalized, we recommend that we be engaged to review those portions of the specifications and drawings that relate to geotechnical considerations to see that our recommendations have been interpreted and implemented as intended. ' There are possible variations in subsurface conditions between the locations of explorations. Variations may also occur with time. Some contingency for unanticipated conditions should be included in the project budget and schedule. We strongly recommend that sufficient monitoring, testing and, consultation be provided by our firm during construction to (1)determine if the conditions encountered are consistent with those indicated by the explorations, (2) provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and (3) evaluate whether or not earthwork and foundation installation activities ' comply with the contract plans and specifications. Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in this area at the time the report was prepared. No warranty or other conditions, express or implied, should be understood. ' G e o E n g i n e e r s 16 File No. 2074-004-00-1130\061899 We trust this provides the information you require at this time. We appreciate the - opportunity to be of service to you on this project. Please contact us should you have any ' questions concerning our findings or recommendations, or should you require additional information. / Respectfully submitted, S NI c ,g WA,��d G�o EB o gineers, Inc. �LQ C o 2 Bob Metca fe, P.E. 6693 � w /�eotechnical E ineeri; �• ISTER �� / i s`S GNAL S�G EXPIRES -3 4 01 �McFadden, P.E. ssociate JJM:ja:pb ' 2074004\00\finals\207400400r.doc ' G e o E n g i n e e r s 17 File No. 2074-004-00-1130\061899 CTH Ir )ST° I ,mj' 1 1_MC 7� N ST 7 lA £ ST PL JST ]St. 16 it«? . Pl SE ' 1D6TH 1 100 >3 SSE 4 E . „ WR ST H S VcA- si �q sF 1.aTN s, a S1 ' �q�f 142N0 ST Z SE_ ,•J:.�� ?L vL SE nl I � +r Y , t 1 �a ida ^ ST 64 Tr Y 1� P T S5; et64TF V iCFO . �K R/jj N'. 8 ♦ 5SM 4 k C4 \ s'+Syt 7 yrr r CEOIq 22 ..a 20 rE r TE Av 21, P`: �?; '�` �. ' !�FNTpy leia < , a `sE <FF� SCHOOL �\J'r Sal LPL : a \_ ^ .,off ,,� St .I' SE-16MC .: ...W d' EF dF ` BSI 1 G ST;R rr ¢it r1.-Tr��hT� I x /y $ CT d✓ sF - a' r me s Rti,,ttl {' 7,v '� r f Z u t57M zr SE 7n (sc ?, 5'qa�. •• ,`: �77r° std.�., 'A Six i� �``' Is! T•91t� et"'Tar la•7 - h it 'S aS �. < � 3•• fy CT) _ ( �751! ,•�' 156M µ 00 PUGE7' �,Al. E e60 ,yWn FA I RG!0 0 - 6E 1501" F SC ST Si 8 S 160rN St SC 159iN Il ;� vl A 159 TN ,,, <1 Ill $T �ry SE x 161 T� ��ST 5(160fN rl d � Sc 1595 SF i 62N0 < <I ST 1 jEa5t ��c x,moo`g,W u 161ST M ----~ a I f62N r• 5[�16 ST SE 160RO ST -i 767767�� cf5 �t � :�_'"^ '< �O - 167b��' "i'1B .� �'O .`.b tl ICT.o. 51 167N0 ' S 27TH ST S;—_ 1 4TH ST SE 164TH! �i STI = =I: "' ~l" �,�I z, ;: �^ °iy� i/16 si Y U� 10900 15�657H 'i�4 I1700$ 165TH ST y�`SE SE 16STH t SE 164TH $�• E.' SI �a7°D+' =��;�tn �JF , 1_u h IRN00 a » !6 rN s1 �''ti, S=r� �! SE 1661N SI m � FA E 166TM -79TN ST < ` s+-KI7 : / /y�,�, J! u —114 Sr w ST SF 167M Sr > 5C�166 TN vl`� 2/?! � � t ►GCIREE$A �o f' ...� a' j Ya• 67T" rt ■LIH08ERGH HS SL 1 6TH Pt 7 -.Ire . 16r 0 2/ S' \�!y t `• > n E 33 _. 168TH ^' _ ST U p = SE < < 29 l,-, o�. Sf '�' « N w N:+SE 169 ST n F�.. O~ _...STN,,, O) $ SE I69TH l SE 169TH _ >o ��' - < `� <28 s 169T n sf Jr Ilz ry' : �.••S �17T110TH $7 J 'EV � nl te 01 HSE51 SE 171 T W sM IIOfN !I1A ~I SE T 72HD ST co `r-r N 1t15t o< > SE 171 .,,„ O I------ �- SE 17 DI^ < ST p a•4.i _^"r Y v(si AI I0800 ! ay SE 112Hp•17f� =�` 12200 r 12 �i� SE 17tsr F o< sE K Y ItSM� e a 'rf ry ` 41rr SE S r lnit v7 �... 60L AV 5E` �•L' S[I73R0 ST S I73R0Y1: SE'<i r 174M Si WI !^ •; PLi S !.� nr i S'S9. J>/` Y _ ■,S SE 175TH "'xt ��118rN ,'; AY SE I ��'<N .N-, `til �'(S`h` s7 0",° 1'3-/t �r C! SE 176TH sr ;! ST �� FETR)V �j6tN SS1 se EAIR1,000 \� SE i, o�o 4I -711000 MI NI ol... I SOWRE -1 I e,y R 8 - O 0 0 2000 4000 .r- o SCALE IN FEET N 0 0 (V Reproduced with permission granted by THOMAS BROS. MAPS. This map is copyrighted by THOMAS BROS. MAPS. It is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without permission. 0 VICINITY MAP GeoeEngineers FIGURE 1 0 t ~~B-12 a _ E< x \ ,f: ,'� '^``.-....J-... fir.,...--.....• � °..-J,- � ...., � ♦ `;, - l . :' :'\ <` �....y��.. 2 ;:►du:ti—Use Turf Fie�d a: 4. • Perki ng `. ` 1 3 ,, ✓ ;\ MAIN Monm lovered ay \'` a / \ , ,� New Multi—Use Pl COVERM MAY \,.. ��•.` '� AddttlOn �`\ .+ ,ram`••''.•• ..�., ♦`., ```' `�; I ♦. y`1\ \ � '' i. �_, �q �mow,.,,..-... ,\-� '\'�-`� f>:,%.��' ' O ,\ 1.\ �`��`. \\` (TO IMlINIQ \ \ i;' \� � aQ:"' \ . ......:r''+ .✓ � -.;J.•-�.. `:,C�. \'`f�.i`+. `,. \`v\ '' ?`ii. . ' \ _ ti!f Parking ` U o EXPLANATION: ' o �r = N B-1 -�- APPROXIMATE BORING LOCATIONt / PROPOSED IMPROVEMENTS (APPROX. LOCATION) �;\ / SCALE IN FEET Note: The locations of all features shown are approximate. SITE PLAN Q Reference: Base Map Prepared by D.A. Berg, INC. dated April 28, 1999. Proposed Improvement taken from Geo > Drawing entitled "Tiffany Park Elementary Renton, Washington, Preliminary Site Plan" by Weisman Design \.O •r1eerS FIGURE 2 Group dated 04/20/99. ��'; � 1�� �• is -- v 1 `� (� x,' .J � `'� _ , ` APPENDIX A i v , " �. . -FIELD EXPLORATIONS._, No.2074-004-00-1�30 (� e �O�En'gtaeeta — APPENDIX A FIELD EXPLORATIONS We explored subsurface soil and groundwater conditions at the site by drilling twelve borings ' (13-1 through B-12)to depths ranging from 9 to 23.5 feet below the existing ground surface. Holt Drilling Inc. of Puyallup, Washington completed the borings on May 5 and 6, 1999 using track- mounted drilling equipment with hollow-stem augers. Locations of the borings were determined in the field by pacing or measuring distances from existing site features and/or matching the contours on the site survey prepared by D.A. Berg, Inc. dated April 28, 1999. Ground surface elevations shown on the boring logs are based on the same topographic map. The locations of the borings are shown on the Site Plan, Figure 2. The borings were continuously monitored by a geologist from our firm who visually ' examined and classified the soils encountered, obtained representative soil samples, observed ground water conditions, and prepared a detailed log of each boring. A 3-inch.outside-diameter, ' heavy-duty split-barrel sampler with brass liner rings was used to obtain relatively undisturbed samples from the borings. A 300-pound safety hammer (wireline)was used to drive the sampler. The blow counts resulting from driving the sampler with the hammer falling 30 inches are ' roughly equivalent to those from the Standard Penetration Test. The number of blows required to drive the sampler the least 12 inches, or other indicated distance, is recorded on the boring logs. Soils encountered were visually classified in general accordance with the classification system described in Figure A-1. A key to the boring log symbols is presented in Figure A-2. The boring logs are presented in Figures A-3 through A-14. The logs are based on our interpretation of the field and laboratory data and indicate the various types of soils encountered. They also indicate the depths at which the soils or their characteristics change, although the change might actually be gradual. The densities noted on the boring logs are based on the blow counts. The ground surface elevations presented on the boring logs are based on the site survey prepared by D. A. Berg, Inc. dated April 28, 1999. The borings were backfilled in general accordance with ' local regulatory requirements. ' G e o E n g i n e e r s A-1 File No.2074-00400-1130\061899 SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP GROUP NAME SYMBOL GW WELL-GRADED GRAVEL,FINE TO COARSE GRAVEL GRAVEL CLEAN GRAVEL ' COARSE GP POORLY-GRADED GRAVEL GRAINED More Than 50% SOILS of Coarse Fraction GM SILTY GRAVEL GRAVEL Retained ' WITH FINES on No.4 Sieve GC CLAYEY GRAVEL SW WELL-GRADED SAND,FINE TO COARSE SAND ' SAND CLEAN SAND More Than 50% Sp POORLY-GRADED SAND Retained on More Than 50% SM SILTY SAND No.200 Sieve of Coarse Fraction SAND Passes WITH FINES SC CLAYEY SAND No.4 Sieve MIL SILT FINE SILT AND CLAY INORGANIC GRAINED CL CLAY SOILS Liquid Limit ORGANIC OL ORGANIC SILT,ORGANIC CLAY Less Than 50 MH SILT OF HIGH PLASTICITY,ELASTIC SILT ' More Than 50% SILT AND CLAY INORGANIC Passes CH CLAY OF HIGH PLASTICITY,FAT CLAY No.200 Sieve Liquid Limit ORGANIC OH ORGANIC CLAY,ORGANIC SILT 50 or More HIGHLY ORGANIC SOILS PT PEAT SOIL PREDOMINANTLY COMPOSED OF COAL FRAGMENTS CF COAL FRAGMENTS (SEE NOTE BELOW) NOTES: SOIL MOSTURE MODIFIERS: 1. Field classification Is based on visual examination of soil in Dry- Absence of moisture,dusty,dry to the touch general accordance with ASTM D2488-90. Moist- Damp,but no visible water ' 2. Soil classification using laboratory tests Is In general accordance with ASTM D2487-90. Wet- Visible free water or saturated,usually soil Is obtained from below 3. Descriptions of soil density or consistency are based on water table Interpretation of blow count data, visual appearance of sills, ' and/or test data. 4. Fill beneath much of the site consists of coal fragments. The coal originated from mining operations conducted on nearby properties. The texture of this material varies, but consists ' predominantly of silt- and sand-size coal fragments with occasional gravel-size fragments. �� SOIL CLASSIFICATION SYSTEM Geo\ Engineers FIGURE A-1 fAsoila-l.doc LABORATORY TESTS SOIL GRAPH: AL Atterberg Limits SM Soil Group Symbol CID Compaction (See Note 2) ' CS Consolidation DS Direct shear GS Grain size %F Percent fines Distinct Contact Between HA Hydrometer Analysis Soil Strata SK Permeability SM Moisture Content Gradual or Approximate MD Moisture and density Location of Change SP Swelling pressure Between Soil Strata TX Triaxial compression UC Unconfined compression CA Chemical analysis Water Level Bottom of Boring ' BLOW COUNT/SAMPLE DATA: ' 22 Location of relatively Blows required to drive a 2.4-inch I.D. undisturbed sample split-barrel sampler 12 inches or 12 ® Location of disturbed sample other indicated distances using a 17 0 Location of sampling attempt 300-pound hammer falling 30 inches. with no recovery 10 0 Location of sample obtained Blows required to drive a 1.5-inch I.D. in general accordance with (SPT) split-barrel sampler 12 inches Standard Penetration Test or other indicated distances using a (ASTM D-1586) procedures 140-pound hammer falling 30 inches. 26 IDLocation of SPT sampling attempt with no recovery © Location of grab sample "P" indicates sampler pushed with N weight of hammer or against weight 0 of drill rig. 0 0 0 0 0 X NOTES: x 1. The reader must refer to the discussion in the report text, the Key to Boring Log Symbols and the exploration logs for a proper understanding of subsurface conditions. ' x 2. Soil classification system is summarized in Figure A-1. x 0 0 0 0 0 KEY TO BORING LOG SYMBOLS Geo�w Engineers FIGURE A-2 TEST DATA BORING B-1 ' DESCRIPTION Moisture Content Density Blow Group Surface Elevation(ft.): t 371 Lab Tests (%) (pcf) Count Samples Symbol 0 ASPHALT 6 inches asphalt over brown sandy fine to coarse gravel(2-inch 0 GW subbase) ML Brownish gray silt(soft,moist)(fill) ' MD 106 45 5 ® OL Dark brown organic silt with 3-inch wood fragments(soft to medium still;moist)(topsoil) 5 ML Brownish gray silt with orange mottles(stiff,moist) 12 2 11 SP Gray fine sand(medium dense,wet) 3 10 ML Brownish gray silt with occasional coarse sand(stiff moist)(slight plasticity) Boring completed at 11.5 feet on 05/05/99 F Ground water encountered at 9.5 feet during drilling w w w LL 4 f' ui = z F- - o_ _ ' p 15 ~ a w 0 5 6 20 n U 7 25 8 0 v 9 Note:See Figure A-2 for explanation of symbols ' ��� LOG OF BORING G e o Engineers FIGURE A-3 1 TEST DATA BORING B-2 ' Moisture DESCRIPTION Dry Content Density Blow Group Surface Elevation(ft.): t 372 Lab Tests (%) (pcf) Count Samples Symbol 0 SOD 3-inch sod layer 0 ' OL Brown organic silt(medium stiff;moist)(fill) ' 1 SM Gray,black and brown silty sand with organic silt inclusions, ' plastic fragments,organics,and charcoal(medium dense,moist) S MD 20 100 12 2 ML Gray silt with orange mottling(stiff moist) ' 3 10 ' CS, 31 94 12 ' AL, MD t- of w w ' w u :: SM Brownish gray silty fine sand with silt layers and orange mottling 4 w z � _ (medium dense,moist to wet) _z f- - o- _ t- ' wp 15 - a w MD 23 105 26 � 5 SM Note: Hard drilling at 17 feet Gray silty fine to coarse sand with fine to coarse gravel(very dense, moist) 6 20 F` 50/5.5" a n: 50/5" Boring completed at 23.5 feet on 05/06/99 No ground water encountered during drilling 25 Q 9 0 ' 30 Note:See Figure A-2 for explanation of symbols ��05- LOG OF BORING Geo� Engineers FIGURE A-4 TEST DATA BORING B-3 DESCRIPTION Moisture Dry Content Density Blow Group Surface Elevation(ft.): t 369.5 Lab Tests (%) (pcf) Count Samples Symbol 0 SOD 6-inch sod layer 0 OUSM Brown organic silt mixed with silty fine to medium sand and occasional organics,rootlets and wood fragments(soft,moist) MD 13 95 3 , OL Dark brown organic silt(soft,moist) 1 ML Gray silt with orange mottling(medium stiff to stiff moist)(slight 5 plasticity) 9 CL Gray and brown lean clay with fine sand,occasional coarse sand 2 and fine to coarse gravel(stiff moist) 15 3 10 SM Note: Hard drilling at 10 feet _ 50/6" ®::::::: Gray silty fine sand with coarse sand and fine to coarse gravel(very ' dense,moist)(till) Boring completed at 11.0 feet on 05/05/99 U) w No ground water encountered during drilling LU ' w u- 4 w z 2 = z_ F- a _ w 15 F- o w 0 5 6 20 U 7 25 8 4v 9 30 Note:See Figure A-2 for explanation of symbols P. LOG OF BORING Geo 1 i Engineers ' FIGURE A-5 TEST DATA BORING B-4 DESCRIPTION Moisture Dry Contend Density Blow Group Surface Elevation(ft.): ±373 Lab Tests (%) (pcf) Count Samples Symbol 0- ASPHALT 3 inches asphalt over 3 inches sandy gravel(subbase) 0 GP Brown and gray clay with fine sand and occasional medium sand, CL fine gravel and wood fragments(soft to medium stiff moist) (fill) 1 5 MD 28 93 5 ' 2 ML Brownish gray silt with fine sand and orange mottling(stiff moist) 10 3 MD 27 101 16 , F- U) W SP-SM Q Brown fine to medium sand with silt(dense,wet) W ' Z Ground water encountered at 13 feet 4 W = z a F p 15 - MD 19 112 31 - 5 ML Gray silt with fine sand layers(hard,moist) ' 6 20 50/3" Boring completed at 21.0 feet on 05/06/99 — Ground water encountered at 13.0 feet during drilling L) 7 25 8 v 9 30 Note:See Figure A-2 for explanation of symbols ��� LOG OF BORING Geo �Eng1neers FIGURE A-6 TEST DATA BORING B-5 DESCRIPTION Moisture Dry Content Density Blow Group Surface Elevation(ft.): t 373 Lab Tests (%) (pcf) Count Samples Symbol 0 0 ASPHALT 2 inches asphalt over 3 inches brown sandy fine gravel base GP Gray silt with fine sand and occasional organic matter(stiff moist) ML (fill)(slight plasticity) 1 ' 5 MD 22 101 13 i 2 Ground water encountered at 8.5 feet perched on top of till 3 10 :: SM Note: Hard drilling at 10 feet :::: MD 10 122 73 Gray silty fine sand with occasional fine gravel(very dense,moist) ' �::: (till) - W w w ' w 4 ~ LL lL z ML Brown and gray laminated fine sandy silt(hard,moist) 2 z n ►_- ' p 15 aUj _ MD 15 118 72 5 Boring completed at 16.5 feet on 05/06/99 Ground water encountered at approximately 8.5 feet during drilling 6 20 7 U 25 8 v 9 30 Note:See Figure A-2 for explanation of symbols �����. LOG OF BORING GA Engineers FIGURE A-7 TEST DATA BORING B-6 Moisture DESCRIPTION Dry Content Density Blow Group Surface Elevation(ft.): t 373.5 Lab Tests (%) (pcf) Count Samples Symbol 0 0 SOD 3-inch sod layer ML Brown,gray and black silt with occasional organic matter(medium stir moist)(fill)(slight plasticity) ' SM 20 7 ® 1 MUSM Gray silt with orange mottling grades to fine sandy silt to silty sand 5 (stiff moist)(slight plasticity) CS, 23 103 10 , AL, 2 ' MD MD 23 103 17 ' 3 10 ML Brownish gray fine sandy silt with orange mottling(very stiff ' MD 20 108 22 i moist) N - m w w ' w 4 U- w z = z :: SM Note: Gravelly drilling at 14 feet = wBrownish gray laminated silty fine sand with occasional large areas F_ p CL 15 of orange mottling(medium dense to dense,moist) W MD 24 104 30 5 Boring completed at 16.5 feet on 05/05/99 No ground water encountered during drilling 6 20 m n 7 U 25 8 0 0 9 a 30 Note:See Figure A-2 for explanation of symbols ' ��� LOG OF BORING G e o .Engineers FIGURE A-8 TEST DATA BORING B-7 DESCRIPTION Moisture Dry Content Density Blow Group Surface Elevation(ft.): f 375 Lab Tests (%) (pcf) Count Samples Symbol 0 SOD 3-inch sod layer 0 ML/SM Mixed brown and gray silt with fine to medium sand and occasional fine to coarse gravel(dense,moist)(fill)(slight plasticity) 1 SM 22 38 '•' 5 2 ML Brownish gray silt with layers of silty fine sand and occasional fine gravel(stiQ moist)(slight plasticity) MD 32 94 12 1 3 10 SP Ground water encountered at 11.5 feet. Brown fine to medium sand(medium dense,wet) _ Cl) ui o: w U 4 w t Z MD 21 107 17 ML Brownish gray silt with layers of fine sand(very still moist)(slight :.. z Fz- plasticity)CL 0 15 w ML Brown and gray laminated silt with fine sand(very dense,moist) o (cemented,looks like siltstone;bedding inclined±30 degrees 5 from horizontal) MD 12 115 50/4" Boring completed at 19.5 feet on 05/06/99 6 20 Ground water encountered at 11.5 feet during drilling n_ U 7 r 25 6 v 9 0 30 Note:See Figure A-2 for explanation of symbols ��� LOG OF BORING Geo�iEngineers FIGURER TEST DATA BORING B-8 DESCRIPTION Moisture Surface Elevation Dry ft. : t 389.5 Content Density Blow Group ( ) Lab Tests (%) (pcf) Count Samples Symbol 0 OL 1 inch forest duff over brownish gray organic silt with occasional 0 charcoal fragments(soft,moist)(fill) MH Mixed brown and gray silt with occasional roots and charcoal fragments(stiff;moist)(fill) MD 28 85 17 1 I i 5 CL Brownish gray clay(medium stiff,moist) 9 2 MH Brown silt with layers of silty fine sand(medium stiff;moist)(slight MD 25 86 9 ® I i I plasticity) Note: Tree root at 9 feet 3 10 I MH Brown silt with fine sand(medium stiff;moist)(tree root in MD 29 93 8 , I i I sampler) LU SM Q Brown silty fine sand with occasional thin silt layers.(medium stiff; w wet) u- MD 30 94 9 Ground water encountered at 12.5 feet. 4 w z S a �- p 15 a w 0 5 ML Gray fine sandy silt with layers of fine sand(very stiff;wet) ' MD 25 101 27 ML Gray silt with occasional layers of fine sand and silty fine sand 6 20 (stir moist)(slight plasticity) � MD 26 98 20 Boring completed at 21.5 feet on 05/05/99 Ground water encountered at 12.5 feet during drilling 7 U 25 ' 8 0 9 c 30 Note:See Figure A-2 for explanation of symbols ��� LOG OF BORING Geo i Engineers FIGURE A-10 TEST DATA BORING B-9 ' DESCRIPTION Moisture Dry Content Density Blow Group Surface Elevation(ft.): t 377 Lab Tests (%) (pcf) Count Samples Symbol ' 0 0 ASPHALT 3 inches asphalt SM Brown to dark brown silty fine to coarse sand with fine gravel (medium dense,moist)(fill) 1 5 MD 9 114 21 ' 2 SM Brownish gray silty fine sand with coarse sand and occasional fine 3 10 to coarse gravel(very dense,moist)(till) MD 12 125 90/101, rn w 4 w LL - ~ w z z z a H MD 8 114 50/6" 5 Boring completed at 16.5 feet on 05/06/99 No ground water encountered during drilling 6 20 m n_ 7 U 25 1 8 $ 9 30 Note:See Figure A 2 for explanation of symbols gdalft LOG OF BORING Geo Engineers ��/ FIGURE A-11 TEST DATA BORING B-10 Dry' DESCRIPTION Moisture Content Density Blow Group Surface Elevation(ft.): t 378 Lab Tests (%) (pcf) Count Samples Symbol 0 0 - SOD 3-to 4-inch sod layer SM Brown with black silty fine to medium sand(medium dense,moist) (fill) SM Orangish brown silty fine to coarse sand with fine to coarse gravel SM 8 31 (dense,moist) 1 ' GM Brown silty fine to coarse gravel with medium to coarse sand(very 5 dense,moist) 72 2 ' P. SM Brown silty fine to coarse sand with fine gravel and occasional coarse gravel(very dense,moist) 50/5.5" ' Boring completed at 9.0 feet on 05/05/99 No ground water encountered during drilling 3 10 �- W ' w 4 u ~ w z z � x aLLJ a_ F— ' 0 15 w 0 5 6 20 m _. 7 25 ' S 0 0 9 30 Note:See Figure A-2 for explanation of symbols ' /��to. LOG OF BORING Geo 1 Engineers FIGURE A-12 TEST DATA BORING B-11 DESCRIPTION Moisture Dry Content Deruity Blow Group Surface Elevation(ft.): t 380 Lab Tests (^/o) (pcf) Count Samples S ymbol 0 0 '. SOD 3-inch sod layer SM Gray-brown silty fine sand with occasional coarse sand and fine to coarse gravel and organic matter(loose,moist)(fill) MD 18 112 6 1 ' ML Dark brown silt with occasional charcoal fragments(medium stiff 5 moist to wet)(fill) MD 41 74 7 ' SM Gray silty fine sand(loose,moist to wet) 2 MH Gray silt with occasional layers of fine sand and silty sand(soft to 3 10 ® I i I medium sti$moist) 4 U) W w z 7 , I I 4 z z a Boring completed at 14.0 feet on 05/05/99 a p 15 No ground water encountered during drilling W 0 5 6 20 m n_ 7 U 25 ' 8 g g v 30 Note:See Figure A-2 for explanation of symbols ' �0.16 LOG OF BORING Geo Engineers FIGURE A-13 TEST DATA BORING B-12 DESCRIPTION Moisture Dry Surface Elevation ft. : f 382 Content Blity Blow Group ( ) Lab Tests (0/0) (pcf) Count Samples Symbol 0 0 SOD 3-inch sod layer OL Brown and dark brown organic silt(soft,moist) ' ML Light brown fine sandy silt with occasional coarse sand and fine GS, 12 121 23 , gravel(medium dense,moist) 1 MD 5 18 SM Brown silty fine to medium sand with occasional fine roots(dense, 2 ' moist to wet) SM Brown silty fine sand with coarse sand and occasional fine gravel MD 10 127 47 (dense to very dense,moist) ® 3 10 Boring completed at 11.5 feet on 05/05/99 � w No ground water encountered during drillinguj 4 w u z z x - �, x a _ ~ a ' p 15 W 0 5 6 20 rn r U 25 8 0 9 v 30 Note:See Figure A-2 for explanation of symbols ' ��111. LOG OF BORING Geo&NEngineers FIGURE A-14 L \ Iti r• �s APPENDIX B LABORATORY TESTING i a _ G e 0 E n=g t p e-e us File No. 2074 004 00-1130 APPENDIX B LABORATORY TESTING GENERAL Soil samples obtained from the. borings were transported to our laboratory and examined to ' confirm or modify field classifications, as well as to evaluate strength and consolidation properties of the soil. Representative samples were selected for laboratory testing consisting of moisture content and density determinations, sieve analyses, and Atterberg Limits and ' consolidation tests. The tests were performed in general accordance with test methods of the American Society for Testing and Materials (ASTM) or other applicable procedures. ' The results of the laboratory tests are presented in Figures B-1 through B-4. The results of the moisture content and dry density determinations are presented on the exploration logs at the respective sample depth in Appendix A. VISUAL CLASSIFICATIONS All soil samples obtained from the borings were visually classified in the field and/or in our laboratory using a system based on the Unified Soil Classification System (USCS) and ASTM classification methods. ASTM test method D 2488 was used to visually classify the soil samples, ' while ASTM D 2487 was used to classify the soils based on laboratory tests results. These classification procedures are incorporated in the boring logs shown in Figures A-3 though A-14, ' in Appendix A. MOISTURE CONTENT DETERMINATIONS ' Moisture contents were determined in general accordance with ASTM D 2216 for numerous samples obtained from the borings. The results of these tests are presented on the logs at the respective sample depth in Appendix A. DRY DENSITY DETERMINATIONS Dry densities were determined performed on numerous relatively undisturbed samples obtained with the split-barrel ring sampler in the borings. The tests were conducted in accordance with ASTM D 2937 and the results are presented on the boring logs in Appendix A at the ' respective sample depth. PARTICAL SIZE ANALYSIS Particle size analyses were performed on one sample in general accordance with ASTM D 422. The sample was selected from the cut area where the proposed ball fields will be graded in ' order to the suitability of the soil for on-site use. The wet sieve analysis method.was used to determine the percentage of soil greater than the U.S. No. 200 mesh sieve. The results of the particle size analysis was plotted, classified in general accordance with the USCS, and presented in Figure B-1. ' G e o E n g i n e e r s B-1 He No.2074-004-00-1130\061899 ' ATTERBERG LIMITS Atterberg limits were determined for two lacustrine soil samples, which also were selected ' for consolidation testing. The tests were used to classify the soil as well as to help determine index properties and consolidation characteristics of the lacustrine deposits. The liquid limit and the plastic limit were determined in general accordance with ASTM D 4318. The results of the Atterberg limits are summarized in Figures B-2. The plasticity chart relates the plasticity index (liquid limit minus the plastic limit)to the liquid limit. CONSOLIDATION TESTS One-dimensional consolidation tests were conducted on two relatively undisturbed soil tsamples tested directly from rings from the split-barrel ring sampler. Tests were conducted in B-2 at 10.5 feet bgs and B-6 at 5.5 feet bgs. These samples were selected to best characterize the lacustrine soils that were encountered with respect to the proposed building foundations. We ' conducted the tests in general accordance with ASTM D 2435, using a fixed-ring consolidometer. The primary purpose of the consolidation tests is to aid in the estimation of potential consolidation and secondary settlement upon subsequent building loads. Figures B-3 and B-4 summarize the consolidation test results. 1 1 ' G e o E n g i n e e r s B-2 He No.2074-004-00-1130\061899 2074-004-00 RCM:MBB:mbb 5/21/99(Sieves.ppt) U.S.STANDARD SIEVE SIZE 3" 1.5" 3/4" 3/8" 94 #10 #20 #40 #60 #100 #200 100 CD 90 801— c� 70 m 60 — CD Fn 50 U) Cn 40 30 20 10 0 m 1000 100 10 1 0.1 0.01 0.001 m GRAIN SIZE IN MLLM=S m D G� D C m m cn W cl) GRAVEL SAND SILT OR CLAY m COBBLES COARSE FINE COARSE MEDIUM FINE C cn SYMBOL EXPLORATION SAMPLE SOIL CLASSIFICATION NUMBER DEPTH B-12 3.0' Brown fine sandy silt(MIL) 2074-004-00 RCM:MBB:mbb 5/26/99(Atterbergs.ppt) PLASTICfTY CHART O 60 50 r'►-S' CH or OH x 40 w ►CD—! z P� U30 U) J OH and MH 0 20 :•' CL r OL D 10 CL-ML ML or OL Cu 0 m ;u 0 10 20 30 40 50 60 70 80 90 100 m U r LIQUID LIMIT c m cn Ia ►� � EXPLORATION SAMPLE MOISTURE LIQUID PLASTICITY cn SYMBOL NUMBER DEPTH CONTENT(%) LIMIT(%) INDEX(%) SOIL DESCRIPTION X m rn c r� ® B-2 10.5' 34.9 40 13 Gray silt (ML) r� Q B-6 5.5' 27.1 33 12 Gray clay (CL) 0 .................... ........ ................. .......... ............. ...... ............................................... ............... _ ...... _ ... _ .......--...... ..........................- - ....................... ............. .. ............................... ................ ...............................:.......... .. ....{...............................i............t-------.......... ...i...;.... ................................................... ;....;...r..i.. ' 0.01 ......... .... .. .............. ...... ... - - - - 0.02 _ .-.... - ............... .......................... - - ;.. : : _ .. _ ...... - - 0.03 �. i i v ............... - a`3 ............... ..... - ............... _ t o ........................ ......i.................. ..................... ...... _ -.... i co ....................i......... ........ ..........;... ........ ...............................:.......1..... .............. N C .......................................... .. ....... ......:.. ..................._ .. �j 0.05 .................................. ................... .................. .... ............ ...................._.........._....... _ . - - - ...................................... ................ ..:.. ............. ...... ... ............... ...... ... 0.06 ....................i...........j........;.....;.....I....Y...;..1.. ............... ...... .....i......j....4...j...l..Y......................i.........../-.......Y.....i.........y..i..<.. ...................:..........:.............�.... _............. .. ...... ... ....................j...........j........ ;.....i.....;....;...i..l.. ................ ...... ............. ....... ... ...... ...j...;...;. ...;.. ..;.. ....... .....�.. 0.07 :.. ....................i...........1........1...........i....Y......1...................... ;.......j......j....i...........: .............;...........1........ ;.....{.....f...i..�..j.. ................... ...................:.....�....�...:--.:..:.. ................. ...... _ ... _ ...... ... - - - 0.08 0.1 1 10 100 Pressure (psf*1000) $ SAMPLE SOIL INITIAL INITIAL DRY rn BORING DEPTH CLASSIFICATION MOISTURE DENSITY NUMBER (FEET) CONTENT (LBS/FT3) Ln o B-2 10.5 Gray sift (ML) 31 94 a U 0 4t$vl ���� CONSOLIDATION TEST RESULTS N Geo Engineers FIGURE B-3 � 0 . ................................... .......... ........................................... ....................................... ...............................:... . ............. ................................................................... ................ ...... .. 0.01 . . _ ..._. .................... _ ................... ................... ........ 0.02 - ......... ...... .. ---•- .. •------------ --•-- -• - - .... ...... .. .. ................................ .. ............... .................... ;.... -..s.. ...................».-.............-.. ..... ... _ ............... .. ..................... _ ... 's 0.03 c .. . .. ...... ....... . ............................. Cn v .......................... ...... ....i....i.. _... 0.04 o ................... .................. ......... _ ........................ _ CU ....................F....................;.....:.........r......................................�.............`....;....;...;..;.. . {... .. ............{.......�...�.. ............................................... ....:... .... :.. ............................................ O i i : i............._....i..._ j 0.05 ................... ................ ....... .............................................. ..... ..`...:.................. ... _ ...... .. s .......................................... ...................;...........;........,.....;....... ......:..... ..................... <..................;. ;.. . I ............. .. .. ...... ... 0.06 ....................j...........j........j.....�.....j....j..t..-;....... ..i... ...1... ...I......i....j....i...i..;.. ..;... ...1.. ..:...............i...i...i.. ...... ...... .. ...... ... .....................:.. ..:... .._...._....:...�..�...�.. ....................................... ......... ...... ... ......................................... y.....;.....,...........,...................... ... 0.07 ....................y...........j........j...--.....-i....i..y...i... ...... .- ............... ...... ... ------------ ........................................:................« ..................... ...... .. ...... .. _ :.. 0.08 a 0.1 1 10 100 04 Pressure (psf*1000) N ° INITIAL INITIAL DRY BORING SAMPLE SOIL DEPTH CLASSIFICATION MOISTURE DENSITY r NUMBER (FEET) CONTENT (LBS/FT3) Ln o B-6 5.5 Gray clay (CL) 23 103 a U 0 o CONSOLIDATION TEST RESULTS CD it,. o Geo NqA Engineers FIGURE B-4 N /