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HomeMy WebLinkAboutSWP272250(1) Report Geotechnical Engineering Services Proposed Puget Western Business Park Renton, Washington For Puget Western, Inc. March 27, 1992 G e o E n g i n e e r s File No.034MI4-RO1/0392 Geo M Engineers March 27, 1992 Geotechnical, Geoenvironmental and Geologic Services Puget Western, Inc. 19515 North Creek Parkway, Suite 310 Bothell, Washington 98011 Attention: Mr. Bob Farrell We are pleased to submit three copies of our "Report, Geotechnical Engineering Services, Proposed Puget Western Business Park, Renton, Washington." The scope of our services for this study is described in our proposal dated January 14, 1992. Authorization to proceed with the services was provided by Mr. Farrell on January 13 after discussing the proposed scope of our services. Portions of our findings and preliminary recommendations were discussed with Mr. Farrell and Mr. Bob Cunningham of Opus Corporation as they were developed. It has been our pleasure to work with you on this project. If you have any questions regarding the contents of our report or if we may be of further service, please call. Yours very truly, GeoE eers, Inc. 41l z1vZ Ja c Tuttle Principal ncr:;m DOC ID: 0340014.R File No. 0340-014-ROl GeoEngineers,Inc. 8410 154th Avenue N.E. Redmond,WA 98052 Telephone(206)861-6000 Fax(206)861-6050 Printed on recycled paper. CONTENTS Page No. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SITE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 SURFACE CONDITIONS 2 SUBSURFACE CONDITIONS 2 GROUND WATER CONDITIONS 3 CONCLUSIONS AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 GENERAL 3 SITE PREPARATION, PRELOADING AND EARTHWORK 4 Site Preparation 4 Preloading 5 General. 5 Preload and Surcharge Fill. 5 Settlement Monitoring. 6 Structural Fill 6 FOUNDATION SUPPORT 7 LATERAL RESISTANCE 8 FLOOR SLAB SUPPORT 8 PAVEMENTS 8 DRAINAGE CONSIDERATIONS 9 LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 FIGURES Figure No. VICINITY MAP 1 SITE PLAN - NORTH 2 SITE PLAN - SOUTH 3 SETTLEMENT PLATE DETAIL 4 G e o Engineers 1 File No.0340-014-RO1/0392 APPENDICES Pasae No. Appendix A - FIELD EXPLORATIONS AND LABORATORY TESTING A-1 FIELD EXPLORATIONS A-1 LABORATORY TESTING 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-5 Log of Test Pit A-6...A-9 Summary of Moisture Content Data A-10 Consolidation Test Results A-1 1 Atterberg Limits Test Results A-12 G e o E n g i n e e r s 11 File No.0340-014-R01/0392 REPORT GEOTECHNICAL ENGINEERING SERVICES PROPOSED PUGET WESTERN BUSINESS PARK RENTON, WASHINGTON FOR PUGET WESTERN, INC. INTRODUCTION This report presents the results of our geotechnical engineering services for the proposed Puget Western Business Park to be located in Renton, Washington. The location of the site is shown on the Vicinity Map, Figure 1. We have completed two previous studies on the site for Puget Sound Power and Light Company. The details of these studies are presented in our "Phase I Report, Preliminary Geotechnical Engineering Services, Proposed Store Warehouse" dated November 9, 1981 and "Report of Geotechnical Investigation,Planned General Stores Facility" dated February 22, 1982. Our November 1981 study included excavation of test pits across the entire site. Additional test pits and five borings were completed in the southwest portion of the property as part of our February 1982 study. We understand that Buildings 1 through 3, to be located in the east portion of the property, are to be constructed during the initial phase of development of the property. Four other buildings (4 through 7) will be constructed subsequently. The proposed buildings will be build- to-suit and are expected to contain both warehouse and office space. The buildings will have on- grade concrete floor slabs and involve concrete tilt-up panel construction. We further understand that the finished floor will be at about Elevation 21 in Buildings 1 through 5, and at about Elevation 19 in Buildings 6 and 7. The pavement surface will be at about Elevation 17 near Buildings 1 through 5, and about Elevation 16 near Buildings 6 and 7. We discussed the building loads with Mr. Bob Farrell and Mr. Bob Cunningham of Opus Corporation. The planned use of the buildings is not known at this time. We have, therefore, estimated the building wall and column loads based on typical construction of this type in the area. We estimate that the wall loads will be in the range of 2,000 to 3,000 plf (pounds per lineal foot) and the column loads will be between 60 and 70 kips. We anticipate the floor slab loads to be between 250 and 500 psf(pounds per square foot). GeoEngineers is concurrently completing geoenvironmental studies on the site. The results of the geoenvironmental study will be provided in a subsequent report. SCOPE The purpose of our services is to explore subsurface soil and ground water conditions in the area of Buildings 1, 2 and 3 as a basis for establishing geotechnical recommendations and G e o E n g i n e e r s I File No.0340-014-RO1/0392 design criteria for the proposed development. Our specific scope of services includes the following: 1. Excavate seven backhoe test pits to depths of 10 to 12 feet across the eastern portion of the site to evaluate subsurface soil and ground water conditions. 2. Drill 3 borings in the eastern portion of the property to evaluate subsurface conditions. The borings were drilled to depths ranging from 44 to 63 feet. Monitor wells were installed in two of the borings to permit subsequent ground water monitoring and sampling. 3. Evaluate pertinent physical and engineering characteristics of the site soils based on laboratory tests performed. on samples obtained from the borings and test pits. The data obtained supplements data from our previous studies. Laboratory tests include moisture and density determinations, consolidation tests and Atterberg limits determinations. 4. Provide site preparation and earthwork recommendations including recommendations for a preload program to reduce postconstruction settlements in the building areas. 5. Develop foundation design recommendations including allowable soil bearing pressures and settlement estimates for spread footings for the planned type of construction. 6. Provide recommendations for slab-on-grade construction. 7. Provide pavement design recommendations for both parking and roadway areas. 8. Prepare a written report presenting our conclusions, recommendations and supporting data. SITE CONDITIONS SURFACE CONDITIONS The proposed Puget Western Business Park is located on a 34-acre site which is bounded by East Valley Highway on the east, Lind Avenue Southwest on the west, Southwest 23rd Street on the north and Southwest 27th Street on the south. The site includes a low lying area in the north and west and up to 10 feet of debris fill over much of the remainder of the site. The low lying area has been classified as a wetland, along with several smaller areas which are located across portions of the debris fill. Scattered deciduous trees are located along the west and north portions of the site. The low lying wet area is vegetated with grasses and scattered blackberry thickets. The debris fill is vegetated with a mixture of grasses, Scotch broom, blackberries and 15- to 20-foot-high bushes. SUBSURFACE CONDITIONS Subsurface soil and ground water conditions were explored by excavating seven test pits and drilling three test borings in the previously filled east portion of the site. The locations of the test pits and borings are shown on the Site Plans on Figures 2 and 3. A description of the field exploration and laboratory testing procedures, logs of the borings and results of laboratory tests are presented in the appendix. The subsurface soil and ground water conditions encountered are generally consistent with the results of our previous studies. The shallow fill soils encountered in our explorations consist G e o E n g i n e e r s 2 File No.0340-014-R01/0392 of 6 to 12 inches of loose rootmass and silty sand with occasional gravel, concrete debris and wood fragments. These soils were very wet and equipment mobility was extremely limited due to poor traction. The underlying fill generally consists of loose to medium dense silty sand with gravel, concrete debris, brick fragments, scattered asphalt pieces and organic matter. The fill was encountered in both the test pits and borings and extended to depths of about 8 to 12 feet where it overlies a layer of highly compressible peat, organic silt and silt. The test pits generally extended to the surface of this compressible layer, but it was encountered to depths of 14 to 20 feet in the three borings. Boring B-1 encountered loose to medium dense, black to gray silty fine sand and sand with silt below the compressible layer, from a depth of 17 feet to about 55 feet. Dense sand with gravel and sand with silt was encountered below this layer and extended to the bottom of the boring at a depth of 63 feet. Medium dense silty sand, sand with silt and sand was encountered below the compressible layer in boring B-2 from a depth of approximately 20 feet to the bottom of the boring at a depth of 44 feet. Boring B-3 encountered loose to medium dense silty sand below the compressible layer from a depth of about 18 to 23 feet. Loose to medium dense silty sand with lenses of soft to medium stiff silt was encountered from a depth of 23 feet to about 31 feet. Medium dense silty sand was encountered below this layer and extended to the bottom of the boring at a depth of 49 feet. GROUND WATER CONDITIONS Perched ground water was encountered on top of the fill in all the explorations within the upper layer of rootmass and silty sand. Ground water was also encountered during drilling at depths of 7.5 feet and 8.0 feet in borings B-1 and B-2, respectively, and at the ground surface in boring B-3. CONCLUSIONS AND RECOMMENDATIONS GENERAL We conclude that the proposed structures can be satisfactorily supported on conventional shallow foundations and the floor supported as a slab-on-grade provided a preload and surcharge program is implemented to preinduce much of the settlement which will otherwise occur under structural and floor loads. Consolidation of the compressible peat and organic silt encountered at the site under the weight of new fill and building loads will result in some settlement of the structures. We present recommendations in the following subsections for site preparation and earthwork and a preload program to develop satisfactory structural support and to reduce postconstruction settlements to generally acceptable limits for the types or structures planned. We further recommend the use of a surcharge fill pad within the proposed building areas to speed the rate of settlement during the preloading period. Construction of footings and slabs should commence only after settlement due to preload and surcharge fill placement has diminished to acceptable rates. Proper monitoring of settlements during fill placement and during the G e o E n g i n e e r s 3 File No.0340-014-RO1/0392 preloading period is essential. A monitoring program is necessary so that time-rate of settlement information can be obtained and the effective time of completion of surcharge evaluated. SITE PREPARATION, PRELOADING AND EARTHWORK Site Preparation We recommend that building and pavement areas be stripped of all vegetation, root systems and topsoil. Based on our explorations, the stripping necessary will generally be on the order of 6 to 12 inches, but areas requiring greater stripping depths should be expected. The underlying silty sand fill contains a high percentage of fines (silt) and is very moisture-sensitive. Operation of equipment on this soil will be difficult, if not impossible, when wet. If the stripping operations cause disturbance of the underlying fill, additional excavation may be necessary. Disturbance of the shallow subgrade soils should be expected if site preparation work is done during periods of wet weather. Material from the stripping operations should be disposed of off- site or used for landscaping purposes, if practical. The site should be graded to a generally level surface once stripping has been completed. This grading should be done to enhance drainage from the site and prevent ponding of water in areas to receive additional fill. All pieces of debris and rubble larger than about 6 inches in maximum dimension should be removed and disposed of off site. The exposed subgrades in roadway, parking and building areas should be evaluated after initial site grading is complete. Proofrolling with heavy rubber-tired construction equipment should be used for this purpose. The site should be proofrolled only during dry weather. Probing should be used to evaluate the subgrade during periods of wet weather. Any soft areas noted during proofrolling or probing should be excavated and replaced with compacted structural fill. We recommend that temporary roads and laydown areas be constructed to reduce the risk of disturbing the subgrade soils. In our opinion, temporary roads should consist of 12-18 inches of quarry spalls or structural fill over a geotextile. The geotextile should be a woven fabric intended for soil separation and reinforcement within roadway embankments. The design pavement sections specified in a subsequent section of this report are not intended to support heavy construction traffic. If pavement or subbase is placed while building construction is still in progress the areas of pavement or subbase should be roped off to prevent vehicle access. This is to reduce the risk of softening of the subgrade, contamination of the subbase soils or pavement failure. As described in a subsequent section of this report, we recommend that all footings be founded on a minimum thickness of structural fill. The excavation required to achieve this thickness should be accomplished after the existing fill surface has been prepared but prior to placing additional fill in the building areas. Effective erosion and sedimentation controls should be implemented during construction so that impacts to the on-site wetlands and adjacent properties are minimized. In our opinion, the G e o E n g i n e e r s 4 File No.0340-014-RO1/0392 erosion potential of the on-site soils is high. The erosion and sedimentation control measures used for this project should be in accordance with the requirements of City of Renton. Preloading General. We estimate that without preloading the building areas the structures could experience total settlements during and following construction on the order of 3 to 5 inches and differential settlements of 2 to 3 inches, depending on actual building load distributions. Settlements of this amount are generally unacceptable for structures such as those proposed for this site. We recommend preloading the building areas of the site to reduce postconstruction settlements. Additional loading (surcharge) is also recommended to speed the rate of induced settlements. Preloading involves placing excess fill (above the fill required for site grading) over the proposed building areas prior to construction. The excess fill is designed to simulate all, or a portion of, the areal loads which will be imposed by the structure and design floor loads. Surcharge loads include any additional loads applied in excess of those required to simulate the total areal structure and design floor loads. The thickness of preload and surcharge fill and the time it remains in place depends on soil conditions, design building loads,and the amount of postconstruction settlement the structure can tolerate. Settlements should be monitored during the preload period using settlement plates. After the desired consolidation is achieved, the preload and surcharge fill is removed and the building foundations and floor slabs constructed. The preload and surcharge fill is typically used to complete other earthwork outside the building areas. The amount of excess import fill which would need to be removed from the site can frequently be reduced or eliminated by coordinating preload quantities and site grade quantities. With a properly designed, constructed and monitored preload and surcharge program, much of the postconstruction settlement which would otherwise occur due to building and floor loads is eliminated. Some postconstruction settlements should still be expected as a result of recompression of the soil and continued secondary consolidation of the layers of peat and organic silt. Preload and Surcharge Fill. We recommend that the preload and surcharge fill height be 4 feet in slab and footing areas. These estimates are based on the assumption that design floor loads will be 250 psf and design footing pressure will be 2,500 psf. For design floor loads of 500 psf, a preload and surcharge fill height of 6 feet is recommended. The full height of the fill should extend beyond the building foundation lines by 5 feet and then slope down to the surrounding grade at about 1H:1V (horizontal to vertical). It is necessary to compact the fill only to the degree necessary for equipment mobility. We recommend that the same material specified for structural fill in a following section be used for the preload and surcharge fill. This will allow its use as structural fill in other areas once it is removed. We expect that the majority of the settlement will occur within about 4 to 6 weeks after the full height of fill is in place. We estimate that postconstruction settlements due to the areal fill G e o E n g i n e e r s 5 File No.0340-014-R01/0392 and floor loadings will be on the order of 1 inch. This settlement is expected to occur over a period of several years. Settlement Monitoring. A typical preload monitoring program consists of installing settlement plates at selected locations in the building areas and surveying the top of rods welded to these plates prior to, during and after the fill is placed. The survey data is used to prepare settlement versus time plots. By extrapolating these plots, we can refine our estimates of when the preload fill can be removed. The settlement plates should be installed once initial site grading is completed and prior to placing structural fill for building pads. Typical settlement plate details and monitoring recommendations are presented in Figure 4. We expect that significant variation in settlement will occur across the site. We recommend that settlement plates be laid out along the building centerlines and be spaced at no more than 100 feet. The plates should be placed no closer than 50 feet in from the edge of the building and should cover any irregularly shaped portions of the buildings. We should review the final settlement plate layout before they are installed. Initial elevation readings of the settlement plates must be obtained when they are placed and before any fill is placed. If this is not done, the initial settlements of the fill pad will not be recorded and the value of subsequent observations diminished because the total magnitude of settlement will be unknown. The elevations of the settlement plates should be determined on Monday, Wednesday and Friday during fill placement and twice weekly for the first two weeks after the fill is in place. Weekly readings will be adequate after this period. The presence of settlement rods extending above the fill will inhibit the mobility of earthmoving equipment. The contractor will have to exercise care to avoid damaging the rods. If the rods are damaged during site grading operation the contractor should repair them at once and reestablish the plate elevation to allow continued monitoring. Structural Fill All new fill 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 on-site soils are not suitable for use as structural fill and imported sand and gravel will be required. We recommend that all imported sand and gravel contain less than 5 percent fines (material passing U.S. Standard No. 200 sieve) by weight relative to the fraction of the material passing the 3/4-inch sieve. This material should be free of debris, organic contaminants and rock fragments larger than 6 inches. All structural fill should be mechanically compacted to a firm, nonyielding condition. Structural fill placers in building areas should be compacted to at least 95 percent of the maximum dry density in accordance with ASTM D-1557. Pavement area fill, including utility trench backfill, should be compacted to at least 90 percent, except for the upper 2 feet below finished subgrade surface, which should be compacted to 95 percent. Structural fill should be placed in loose lifts not exceeding 8 to 10 inches in thickness. Each lift should be conditioned to the G e o E n g i n e e r s 6 File No. 0340-014R01/0392 proper moisture content and compacted to the specified density before placing subsequent lifts. We recommend that a representative from our firm be present during proofrolling and/or probing of the exposed subgrade soils in building and 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 work is being done in compliance with the compaction specifications, and advise on any modifications to procedure which might be appropriate for the prevailing conditions. FOUNDATION SUPPORT We recommend that the new buildings be supported on conventional spread footings bearing on a pad of structural fill with a minimum thickness of 2 feet or one-half the width of the footing, whichever is greater. The structural fill pad will provide more uniform bearing support than the existing fill 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 the thickness of the fill. Excavation for and placement of this fill should be done prior to construction of the building pad fill and preloading so that the subsequent footing construction can be accomplished with less disturbance to the building pad fill. Loose or disturbed soils not removed from excavations for the structural fill beneath footings will contribute to increased settlements. The silty material encountered in our explorations is susceptible to disturbance. Additional excavation may be required at soft and disturbed areas to provide a suitable bearing surface for the structural fill if the existing fill cannot be compacted. The exposed soils must be protected from softening or other disturbance. Structural fill should be placed as soon as each excavation is completed. When footings are constructed, the exposed bearing surface should also be recompacted. We recommend that exterior footings be founded at least 18 inches below lowest adjacent finished grade. Interior footings should be founded a minimum of 12 inches below top of slab. Continuous wall footings and individual column footings should have minimum widths of 24 inches and 36 inches, respectively. The recommended allowable bearing pressure for footings supported on properly prepared structural fill is 2,500 psf. The allowable soil bearing pressure is for 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 settlements of footings founded on structural fill as recommended will be in the range of 3/4 to 1 inch, depending on actual foundation loads and underlying soil conditions. Much of the settlement due to applied dead loads will occur within a short time after the walls and roof structure is in place. Postconstruction footing settlements should be less than 1/2 inch. Maximum differential settlements between adjacent comparably loaded individual column footings or along a 50-foot length of wall footing should also be less than 1/2 inch. We recommend that we be retained to review our estimates of expected settlement performance of individual structures once design column and wall loads have been determined. G c o E n g i n c c r a 7 File No.0340-014R01/0392 We recommend that all excavations for the fill pad and for footing construction be observed by a representative from our firm to determine if the work is completed in accordance with our recommendations and that subsurface conditions are as expected. LATERAL RESISTANCE Lateral loads on building footings can be resisted by passive resistance on the sides of the footings and by friction on the base of the footings and slab. Passive resistance should be evaluated using an equivalent fluid density of 300 pounds per cubic foot (pcf) where footings are surrounded by structural fill compacted to 95 percent of maximum dry density as recommended above. Passive pressure resistance should be calculated from the bottom of adjacent floor slabs or paving or below a depth of 1 foot where the adjacent area is unpaved, as appropriate. Frictional resistance can be evaluated using 0.4 for the coefficient of base friction against footings and the building slab. The above values incorporate a factor of safety of about 1.5. FLOOR SLAB SUPPORT We recommend that the floor slabs be founded on a minimum of 1 foot of structural fill. Any areas disturbed by construction activities should be recompacted before proceeding with slab construction. We recommend that a base course consisting of 4 inches of free-draining gravel containing less than 3 percent fines be placed beneath the slab to provide uniform support and serve as a capillary break to reduce moisture migration through the slab. This layer can be included as part of the 1-foot minimum thickness of structural fill recommended above. In our opinion, a vapor barrier such as plastic sheeting is not needed beneath the slab if the structural fill consists of clean sand and gravel as previously specified. Postconstruction settlement of slabs supported as recommended due to the applied floor loads should be in the range of 1/2 to 1 inch provided the area has been properly preloaded. These settlements may occur over a period of several years, depending on load history in the buildings. Differential settlements of the floors depend, in part, on how uniformly the buildings are loaded. We recommend that the slab be reinforced to reduce the potential for cracking due to differential settlements. PAVEMENTS The exposed fill subgrade in pavement areas should be proofrolled or otherwise examined to detect areas of soft subgrade or unsuitable soils. 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. In soft subgrade areas, we recommend that consideration be given to placing a woven geotextile between the native soils and the structural fill as a separation layer. G e o E n g i n e e r s 8 File No.0340-014-RO1/0392 Provided the subgrade is prepared as recommended and that pavement construction is done during a period of extended dry weather, we recommend that the pavement section in automobile parking areas consist of minimum thicknesses of 2 inches of Class B asphalt concrete, 4 inches of clean crushed rock base, and a subbase consisting of 8 inches of structural fill. In roadway and truck loading areas, the minimum thicknesses should be 3 inches of asphalt concrete, 6 inches of crushed rock base and 8 inches structural fill. The structural fill should meet the requirements previously specified for gradation and compaction. The crushed rock base course and granular fill 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 also be compacted as specified for structural fill. The above pavement section recommendations are based on having a relatively dry and stable subgrade on which to place the subbase, base course and paving. Some differential settlement of pavement areas is expected due to the variable nature of the existing fill and underlying soft soils. We recommend that final paving be delayed as long as possible once the subgrade has been prepared and the structural fill subbase has been placed to allow for some settlement to occur. DRAINAGE CONSIDERATIONS We expect that shallow perched ground water could be encountered during footing and utility excavation. We anticipate that this water can be temporarily handled during construction by ditching and sump pumping, as necessary. All collected water should be safely routed to suitable discharge points. Roof drains should be tightlined and routed to suitable discharge points. 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 Puget Western, Inc. and other members of the project team for use in design of portions of the planned development. 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. The project was in the design development stage at the time this report was prepared. We expect that further consultation regarding specific design elements will be necessary. When the design has been finalized, we recommend that GeoEngineers be retained to review the final design drawings and specifications to see that our recommendations have been interpreted and implemented as intended. G e o E n g i n e e r s 9 File No.034M14-R01l0392 Our scope does not include services related to construction safety precautions and our recommendations are not intended to direct the contractor's methods, techniques, sequences or procedures, except as specifically described in our report for consideration in design. There are possible variations in subsurface conditions between the locations of explorations and also with time. A contingency for unanticipated conditions should be included in the project budget and schedule. Sufficient monitoring, testing and consultation should be provided by our firm during construction to determine if the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not earthwork 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 other conditions, express or implied, should be understood. O ► We appreciate the opportunity to be of service to you. If you have any questions concerning this report or if we can provide additional services, please call. Respectfully submitted, GeoEngineers, Inc. K. T U7, G W ASN �� ;• o M adden Proj Engineer w G� O o �GISTEg� 0 N A1, Ja K. Tuttle EXPIRES rincipal JJM:JKT:ira DOC ID: 0340014.R G e o E n g i n e c r s 10 File No.0340-014-RO1/0392 13 BM em , s Golf Lour\ 19 Longacre$: ' C W, Track i \1 ��' n$� I '• — �S�. j'• II;, IBMev i29 : ---'-- — — — _ • I .✓ SITE :. IA I 25 w30 ? B- )ZM v 2 C9 h� 16SM _ o 17 I 94 „ I: 1, .0rillia 1 ) p_; � •. � N q 0 2000 4000 SCALE IN FEET v Reference: USGS 7.5' topographic quadrangle map entitled 'Renton, Washington,* dated 1973. o � VICINITY MAP Geo 1r Engineers FIGURE 1 0 S. W. 23RD STREET o a .I N e'., 6,2 of W I .« I V iTG f} AI i W,z to U 4 � fjsJ I I WETLAW AREA 7 12 _— I1J / -ac z r'% Q W Q �I_W B-1 _ I I 1 / ; � LL PD[ T{P , TP-1 II I ~/� I ) n ns 0 \, F TP-2 Q BUILDING '1' aj W j I V .009 I I j tAND 3 j vl (Fn\.FM.03 �r R,r) S / t DC90-04 ♦Cy j e 3n.s 7`r— i -T- - —-- y I I ' F�9Jce3> l' BUILDING" WETLAND 4. (MLE- .42 A 4 —Asp\- .,\ �GV1r ti EXPLANATION: - TP-7 w i ,\ B-1+ BORING BY GEOENGINEERS FOR CURRENT STUDY TP-2-i� TEST PIT BY GEOENGINEERS FOR CURRENT STUDY N 0 100 200 3-f TEST PIT BY GEOENGINEERS FOR PREVIOUS STUDIES SCALE IN FEET DATED 10/26/81 AND 02/2-2/82 1 BORING BYGEOENGINEERS FOR PREVIOUS STUDY Reference: Map by Lance Mueller&Associates entitled'Puget Western Business Park, o DATED 02/22/82 u9 k Renton, Washington,' revision dated 05/0,,/91. B90-01 - - BORING BY OTHERS FOR PREVIOUS STUDIES to, SITE PLAN - NORTH D DC90-03 Z� DUTCH CONE BY OTHERS FOR PREVIOUS STUDIES Geo\�Engineers o �� FIGURE 2 ' e 21 J `tee See Fig is; 0 -- VAMAM AREA 2 _ fR11 MAL FILL.06 AGRESr � -21 — L m 4 -- n 110 I 1J 2 Pig tr I I I r _1 .4+ 20 N ;" - ;� i /111 i BUILDING '3' �' �I`- I . asy �,a =-a= _ zv - - -- _- i \ P74 w Goc�, Cl) LLJ • �', + I1, I 4 L M.pJN��p W61r + 3 . -J 11ETLAfO AREA 6 s ,tLil 13z �V V 14 "L' iR 3 �w--- - - GJA:-frr AREA . J J I Kc. RAepr-cE ¢5 RT I DC90-03 ' 17 BUILDING '6' BUILDING 7 , Q 19 �rw 5 REA I �or.eaa "'° ` ( W 7 ��^ — eF PRoPER7 Q 71 / DC90-02 i � \WETLAND AREA 6/ J aweri�a�.a / vn 411 H.a &epwA e L� ti EXPLANATION: S.W. 27TH STREET 13-3 +, ' BORING BY GEOENGINEERS FOR CURRENT STUDY N 0 100 200 TP-4 {} TEST PIT BY GEOENGINEERS FOR CURRENT STUDY SCALE IN FEET 1 17* TEST PIT BY GEOENGINEERS FOR PREVIOUS STUDIES �2 DATED 10/26/81 AND 02/22/82 1 BORING BY GEOENGINEERS FOR PREVIOUS STUDY Reference: Map by Lance Mueller&Associates entitled'Puget Westem Business Park, DATED 02/22/82 Renton,Washington;revision dated 05/01/91. a B90-01-� BORING BY OTHERS FOR PREVIOUS STUDIES SITE PLAN - SOUTH 0 DC90-03,L DUTCH CONE BY OTHERS FOR PREVIOUS STUDIES Geo v Engineers D FIGURE 3 MEASUREMENT ROD, 112" 0 PIPE OR REBAR CASING, 2" 0 PIPE (SET ON PLATE, NOT FASTENED) EXISTING COUPLING WELDED TO PLATE GROUND SURFACE SETTLEMENT PLATE, 16" X 16" X 1 /4" I\ SAND PAD IF NECESSARY (NOT TO SCALE ) NOTES : 1 . INSTALL MARKERS ON FIRM GROUND OR ON SAND PADS IF NEEDED FOR STABILITY . TAKE INITIAL READI'JG ON TOP OF ROD AND AT ADJACENT GROUND LEVEL PRIOR TO PLACE- MENT OF ANY FILL . 2 . FOR EASE IN HANDLING, ROD AND CASING ARE USUALLY INSTALLED IN 5-FOOT SECTIONS . AS FILL PROGRESSES, COUPLINGS ARE USED TO INSTALL ADDITIONAL LENGTHS . CONTINUITY IS MAINTAINED BY READING THE TOP OF THE MEASUREMENT ROD, THEN IMMEDIATELY ADDING THE NEW SECTION AND READING THE TOP OF THE ADDED ROD . BOTH READINGS ARE RECORDED . H 3 . RECORD THE ELEVATION OF THE TOP OF THE MEASUREMENT M ROD IN EACH MARKER AT THE RECOMMENDED TIME INTERVALS . q EACH TIME, NOTE THE ELEVATION OF THE ADJACENT FILL SURFACE . 4 . READ THE MARKER TO THE NEAREST 0 . 01 FOOT, OR 0 . 005 o FOOT IF POSSIBLE . NOTE THE FILL ELEV:- TION TO THE NEAREST 0 . 1 FOOT . 5 . THE ELEVATIONS SHOULD BE REFERENCED TO A TEMPORARY BENCHMARK LOCATED ON STABLE GROUND AT LEAST 100 FEES o FROM THE EMBANKMENT. SETTLEMENT PLATE DETAIL Geo\MEngineers FIGURE 4 APPENDIX A APPENDIX A FIELD EXPLORATIONS AND LABORATORY TESTING FIELD EXPLORATIONS Subsurface conditions were explored by excavating seven test pits and drilling three test borings at the site. The test pits were excavated on January 14, 1992 using a rubber-tired backhoe. The test borings were drilled on January 16, 1992 using truck-mounted, hollow-stem auger drilling equipment. Locations of the explorations were determined in the field by measuring distances from site features. Ground surface elevations were determined from topography shown on the site plan entitled "Puget Western Business Park, Renton, Washington" by Lance Mueller & Associates, revision dated 05/01/91. The locations of the explorations are shown on the Site Plan, Figures 2 and 3. The test pit excavations and test borings were continuously monitored by an engineer from our firm who examined and classified the soils encountered, obtained representative soil samples, observed ground water conditions and prepared a detailed log of each exploration. Grab samples were obtained from the various soil layers encountered in the test pits. A 3-inch-outside- diameter, heavy-duty, split-barrel sampler with brass liner rings was used to obtain relatively undisturbed samples. The blow counts resulting from driving this sampler with a 300-pound hammer falling 30 inches are roughly equivalent to those from the Standard Penetration Test. The number of blows required to drive the sampler the last 12 inches, or other indicated distance, is recorded on the boring logs. Soils were 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 test boring logs are presented in Figures A-3 and A-5 and the test pit logs are presented in Figures A-b through A-9. These 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. The densities noted on the test boring logs are based on the blow count data obtained in the borings. The densities noted on the test pit logs are based on the difficulty of digging, probing with a 1/2-inch-diameter hand probe, and our experience and judgment. LABORATORY TESTING The soil samples obtained from the test pits and test borings were further examined in our laboratory. Moisture content determinations were made on selected samples from the test pits for correlation purposes. The results of these determinations are presented in Figure A-10. Moisture and density tests were also completed on samples obtained from the test borings. The results of these tests are presented on the boring logs. In addition, two consolidation tests were completed on samples obtained from the test borings. The results of these tests are presented in Figure A-11. Atterberg limits test results for a sample of the silt are presented in Figure A-12. G e o E n g i n e e r s A - 1 File No.0340-014R01/0392 SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP GROUP NAME SYMBOL GRAVEL CLEAN GRAVEL GW WELL-GRADED GRAVEL,FINE TO COARSE COARSE GRAVEL GRAINED GP POORLY-GRADED GRAVEL SOILS MORE THAN 50% GRAVEL GM SILTY GRAVEL OF COARSE FRACTION WITH FINES RETAINED ON NO. 4 SIEVE GC CLAYEY GRAVEL MORE THAN 60% RETAINED ON SAND CLEAN SAND $W WELL-GRADED SAND, FINE TO NO. 200 SIEVE COARSE SAND SIP POORLY-GRADED SAND MORE THAN 60% SAND SM SILTY SAND OF COARSE FRACTION WITH FINES PASSES NO. 4 SIEVE SC CLAYEY SAND SILT AND CLAY ML SILT FINE INORGANIC GRAINED CL CLAY SOILS LIQUID LIMIT LESS THAN 60 ORGANIC OL ORGANIC SILT, ORGANIC CLAY SILT AND CLAY MH SILT OF HIGH PLASTICITY, ELASTIC SILT MORE THAN 60% INORGANIC PASSES NO. 200 SIEVE CH CLAY OF HIGH PLASTICITY, FAT CLAY LIQUID LIMIT 60 OR MORE ORGANIC OH ORGANIC CLAY, ORGANIC SILT HIGHLY ORGANIC SOILS PT PEAT NOTES: SOIL MOISTURE MODIFIERS: 1. Field classification is based on Dry - Absence of moisture, dusty, dry visual examination of soil In general to the touch accordance with ASTM D2488-84. Moist - Damp, but no visible water 2. Soil classification using laboratory tests is based on ASTM D2487-85. Wet - Visible free water or saturated, usually soil is obtained from 3. Descriptions of soil density or below water table consistency are based on interpretation of biowcount data, visual appearance of soils, and/or test data. r-1 rn p H W its SOIL CLASSIFICATION SYSTEM G e o ig Enoizleers \�/ b FIGURE A-1 FLABORATORY TESTS: SOIL GRAPH: Atterberg limits CompactionSM Soil Group Symbol S Consolidation (See Note 2) DS Direct shear GS Grain - size Distinct Contact Between %F Percent fines Soil Strata HA Hydrometer analysis Gradual or Approximate SK Permeability Location of Change SM Moisture content Between Soil Strata MD Moisture and density SP Swelling pressure Water Level TX Triaxial compression Bottom of Boring UC Unconfined compression CA Chemical analysis 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 other indicated distances using a 12 ® Location of disturbed sample 300-pound hammer falling 30 inches. 17 0 Location of sampling attempt 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 (ASTM D-1586) procedures 140-pound hammer falling 30 inches. 26 m Location of SPT sampling attempt with no recovery ® Location of grab sample "P" indicates sampler pushed with weight of hammer or against weight of drill rig. NOTES: 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. 2. Soil classification system is summarized in Figure A-1. m \� �. KEY TO BORING LOG SYMBOLS G e o 1W Engineers FIGURE A-2 TEST DATA BORING B-1 DESCRIPTION Moisture Dry 3 a° Group Content Dens ityw°U h Symbol Surface Elevation(ft.) : 15.0 Lab Teats (%) cf) 0 SM Brown silty fine to medium sand with gravel and scattered organic 0 SM matter(medium dense,moist)(fill) Gray silty fine to medium sand with gravel(medium dense,moist) (fill) MD 20 100 22 ; 5 5 30 ® Grades to wet LU PT Brown fibrous peat(soft,wet) 10 \„ 10 SM 70 P i I OL Dark brown organic silt and silt with peat(soft,wet) I 1 I ML SM 98 i I I SM 168 15 I I i 15 i I I w LL I I I MD 38 84 7 I I Black to gray silty fine sand to fine sand with silt and occasional a - SP—SM organic matter(loose,wet) 0 20 20 MD 26 97 2 25 25 m SP— Gray fine to medium sand with silt(loose to medium dense,wet) N 4 SM 30 30 U m n MD 24 99 10 Decreasing silt content 35 35 22 a 0 6 40 40 a Note:See Figure A-2 for explanation of symbols ��� LOG OF BORING Geo��Engineers FIGURE A-3 a TEST DATA BORING B-1 (Continued) DESCRIPTION Moisture 2 Dry Group E Content Density . 0 0 It Symbol 40—Lab Tests (pef) co W 40 MD 21 105 10 Scattered shell fragments 45— —45 25 50— —50 MD 30 91 25 55— SW Gray fine sand with gravel and occasional coarse sand(dense,wet) —55 Uj . . . . . LU LL z 45 F- LU 60— —60 SP— Gray fine to medium sand with silt and occasional coarse sand and - SM fine gravel(very dense,wet) MD 19 109 51 Boring completed at 63.0 feet on 01/16/92 65— Ground water encountered at 7.5 feet during drilling 65 rn 70— 70 75— —75 L8 so 0 Note:See Figure A-2 for explanation of symbols LOG OF BORING G K�. NMm eo Enoineers FIGURE A-3 b TEST DATA BORING B-2 DESCRIPTION Moisture Dry o a Group Content Density OaU Symbol Surface Elevation(ft.) : 16.0 0 Lab Tests (%) (pet) 0 SM Brown silty fine to medium sand with scattered gravel and a trace SM of organic matter(medium dense,moist)(fill) Gray silty fine to medium sand with gravel and construction debris (medium dense,moist)(fill) MD 15 94 25XX ■ 5 5 6 10 MD 260 19 4 PT Dark brown peat and organic silt(soft,wet) 10 OL P MkLd CS 178 25 15 MH Gray to dark brown organic silt to silt with scattered fibrous 15 OH organic matter and interbedded fine to medium sand(soft,wet) III Ul LL III MD, 60 62 2 ■ a AL Lu 20 : SM Brown silty fine sand(medium dense,wet) 20 SM Gray to black silty fine sand to silt with a trace of organic matter MD 34 85 22 ■ ML (medium dense,wet) 25 25 SM Gray silty fine to medium sand(medium dense,wet) N O� a26 ■ : •• : SP Gray fine to medium sand with occasional coarse sand and scattered shell fragments(medium dense,wet) 30 30 U f ' y 17 35 SP— Gray fine to medium sand with silt and occasional coarse sand 35 SM (medium dense,wet) 10 ■ a 40 L40 0 Note:See Figure A-2 for explanation of symbols 41r LOG OF BORING Geo 1�Enbineers FIGURE A-4a TEST DATA BORING B-2 (Continued) DESCP=ON Moisture Dry 3 a Group Content Density .2 0 Symbol 40 Lab (%)Tests (Pet) 40 IvM 23 101 39 Boring completed at 44.0 feet on 01/17/92 45 Ground water encountered at 8.0 feet during drilling 45 50 50 55 55 f- w w LL ZUj S a 0 60 60 65 65 m N M 70 70 U m N 75 75 0 a d 80 80 v Note:See Figure A-2 for explanation of symbols .j LOG OF BORING Geo Mw Engineers FIGURE A-4 b TEST DATA BORING B-3 m DESCRIPTION oC EGroup Con me Density �U sn Svmbol Surface Elevation(ft.) : 18.0 0 Lab Tests (%) (pet) 0 SM Brown silty fine to medium sand with gravel and organic matter SM (medium dense,moist)(fill) Brown to gray silty fine to medium sand with gravel,concrete pieces and scattered organic matter(medium dense,wet)(fill) MD 22 94 18 5 5 8 10 10 6 Q PT Brown fibrous peat(soft,wet) CS 97 44 4 OL Gray organic silt with peat(soft,wet) SM Brown silty fine sand(loose to medium dense,wet) 15 15 fXX— w w U- Z = MD 28 94 20 SM Grayish brown silty fine to medium sand with a trace of organic a fvIC matter and fine sandy silt(medium dense and stiff,wet) p 20 20 4 SM Gray silty fine to medium sand interbedded with lenses of gray silt 25 ML (loose and soft,wet) 25 N O) y MD 22 96 3 30 30 SP— Gray fine to medium sand with silt and scattered shell fragments m SM (medium dense,wet) n 10 35 35 S MD 23 101 23 a a 40 140 Note:See Figure A-2 for explanation of symbols \�j LOG OF BORING Geoff Engineers FIGURE A-5 a TEST DATA BORING B-3 (Continued) DESCRIPTION Moisture Dry o Group Content Density —2 0 = Symbol 40 Lab Tests (%) et) 40 10 45 45 37 Boring completed at 49.0 feet on 01/17/92 50 Ground water encountered at the ground surface during drilling 50 55 55 ui w w LL Z H a p 60 60 65 65 n N M 70 70 U m fN 75 75 0 a 0 0 80 80 Note:See Figure A 2 for explanation of symbols � LOG OF BORING Geo 1�Engineers FIGURE A-5 b LOG OF TEST PIT DEPTH BELOW SOIL GROUP GROUND SURFACE CLASSIFICATION (FEET) SYMBOL DESCRIPTION TEST PIT 1 Approximate ground surface elevation: 16 feet 0.0- 1.0 SM Vegetation,root mass and brown silty fine to medium sand with occasional gravel, concrete and wood fragments(loose,moist)(fill) 1.0- 2.5 SP Gray fine to medium sand(loose,wet) 2.5- 10.0 MIJSM Gray fine sandy silt to silty fine to medium sand with occasional concrete debris and rebar(stiff and medium dense,moist)(fill) 10.0- 12.0 PT/OL Brown peat and organic silt with occasional sand(soft,moist) Test pit completed at 12.0 feet on 01/14/92 Moderate ground water seepage observed at 1.0 feet Disturbed soil samples obtained at 9.0 and 1.0 feet TEST PIT 2 Approximate ground surface elevation: 16 feet 0.0- 1.0 SM Vegetation,root mass and brown silty fine to medium sand with gravel, concrete debris and wood fragments(loose,moist)(fill) 1.0- 9.0 SM Gray silty fine to medium sand with gravel, concrete debris and wood fragments (medium dense,moist)(fill) 9.0- 10.0 PT/OL Brown peat with organic silt and fine sand to organic silt(soft, moist) Test pit completed at 10.0 feet on 01/14/92 No ground water seepage observed Disturbed soil samples obtained at 0.5,5.0 and 9.0 feet THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. his. LOG OF TEST PIT Geo\!Engineers FIGURE A-6 DEPTH BELOW SOIL GROUP LOG OF TEST PIT GROUND SURFACE CLASSIFICATION (FEET) SYMBOL DESCRIPTION TEST PIT 3 Approximate ground surface elevation: 18 feet 0.0- 1.0 SM Vegetation, root mass and brown silty fine to medium sand with gravel and occasional concrete debris(medium dense,moist)(fill) 1.0- 9.0 SM Gray silty fine to medium sand with gravel, concrete debris and occasional rebar (medium dense,moist)(fill) 9.0- 9.5 PT/OL Brown peat and organic silt(soft,moist) Test pit completed at 9.5 feet on 01/14/92 No ground water seepage observed Disturbed soil sample obtained at 5.0 feet TEST PIT 4 Approximate ground surface elevation: 17 feet 0.0- 1.0 SM Vegetation, root mass and brown silty fine to medium sand with gravel, brick fragments and concrete debris(loose,wet)(fill) 1.0- 8.5 SM Gray silty fine to coarse sand with occasional gravel,brick fragments and concrete debris(medium dense,moist)(fill) 8.5-9.5 PT/OL Brown peat with organic silt(soft, moist) Test pit completed at 9.5 feet on 01/14/92 Moderate ground water seepage observed at 1.0 foot Disturbed soil samples obtained at 1.0 and 6.0 feet THE DEPTHS ON THE TEST PIT LAGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. -KM LOG OF TEST PIT Geo��Engineers FIGURE A-7 LOG OF TEST PIT DEPTH BELOW SOIL GROUP GROUND SURFACE CLASSIFICATION (FEET) SYMBOL DESCRIPTION TEST PIT S Approximate ground surface elevation: 17 feet 0.0- 1.0 SM Vegetation,root mass and brown silty fine to coarse sand with gravel and occasional concrete debris(loose,wet) (fill) 1.0- 5.0 SM Gray silty fine sand with gravel and concrete debris(medium dense,moist)(fill) Test pit completed at 5.0 feet on 01/14/92 due to refusal on large concrete debris Ground water seepage observed at 1.0 foot Disturbed soil sample obtained at 3.0 feet TEST PIT 6 Approximate ground surface elevation: 16 feet 0.0- 1.0 SM Vegetation, root mass and brown silty fine to medium sand with gravel and occasional concrete debris(loose,wet)(fill) 1.0- 8.0 SM Gray silty fine to medium sand with gravel and occasional concrete debris(medium dense,moist)(fill) 8.0- 9.5 ML/OL Brown silt to organic silt with wood fragments(soft,moist) Test pit completed at 9.5 feet on 01/14/92 Minor ground water seepage observed at 1.0 foot Disturbed soil samples obtained at 2.0 and 9.5 feet THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. LOG OF TEST PIT Geo wZvp Engineers FIGURE A-8 LOG OF TEST PIT DEPTH BELOW SOIL GROUP GROUND SURFACE CLASSIFICATION (FEET) SYMBOL DESCRIPTION TEST PIT 7 Approximate ground surface elevation: 16 feet 0.0- 0.5 SM Vegetation,root mass and brown silty fine to medium sand with gravel and concrete debris(loose,wet) (fill) 0.5- 7.5 SM Grav silty fine to medium sand with gravel and concrete debris (medium dense, moist) (fill) Test pit completed at 7.5 feet on 01/14/92 due to refusal on large concrete debris Ground water seepage observed at 0.5 foot Disturbed soil samples obtained at 3.0 and 5.0 feet THE DEPTHS ON THE TEST Prr LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. LOG OF TEST PIT Geo Engineers\! FIGURE A 9 SUMMARY OF MOISTURE CONTENT DATA* Test Sample Pit Depth *Soil Moisture Number feet Type Content 1 10.0 ML 24 1 11.0 PT 106 2 0.5 SP-SM 11 2 5.0 SM 22 2 9.0 PT 120 3 5.0 SM 12 4 1.0 SM 27 4 6.0 SM 17 5 3.0 SM 11 6 2.0 SM 9 6 9.0 PT 110 7 3.0 SM 13 7 5.0 SM 13 *Refer to test pit togs for complete soil description Q O C O O SUMMARY OF MOISTURE CONTENT DATA Geo Engineers FIGURE A-10 PRESSURE (LBS/FT2 x 103) .1 .2 .3 .4 5 1 2 3 4 5 10 20 30 40 50 I � i I I i I I I I I i I 1 I i . 1000 i I I I I I I I I 2000 I I ► � I U Z �I-- 3000 Z I t I I o I I i I I 1 t I I 4000 0 t/) o i I I I I I ► I t . 5000 � ► I I I I I I I I I I I . 6000 I I I i I ti I I I I I SAMPLE DRY BORING DEPTH SOIL MOISTURE DENSITY KEY NUMBER (FT) CLASSIFICATION CONTENT (LBS/FT3) c B-2 14 DARK BROWN PEAT (PT) 1780 25 c � r —— B-3 13 ORGANIC SILT WITH PEAT 970 44 a j (OL) CONSOLIDATION TEST RESULTS Geo�opoop eers FIGURE A-11 (;I.T 47-8 8 60 PLASTICITY CHART 50 CH w 40 Oro ►�5 30 V OH and MH 20 CL D 10 m CL—ML ML and OL 7D , W m 0 0 10 20 30 40 50 60 70 80 90 100 m r LIQUID LIMIT C 70 -I m N EXPLORATION SAMPLE MOISTURE LIQUID PLASTICITY D m NUMBER DEPTH CONTENT (off LIMIT INDEX (off SOIL DESCRIPTION 7o B-2 18 ' 60 53 10 GRAY TO BROWN SILT WITH m N ORGANIC MATTER (MH/OH) C r