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REVIEWED BLD BLD2021-0286+Geotechnical_Report+3.3.2021_12.35.31_PM+2073819January 22, 2020 ES-7004 Select Homes, Inc. 16531 — 13t" Avenue West, A107 Lynnwood, Washington 98037 Attention: Ms. Kayla Nichols Subject: Geotechnical Evaluation Proposed Single -Family Residences 8805 — 220t" Street Southwest Edmonds, Washington L h ons «C Earth Solutions NW LLC Geotechnical Engineering, Construction Observationjesting and Environmental Services Reference: Department of Ecology Stormwater Management Manual for Western Washington Amended December 2014 James P. Minard Geologic Map of the Edmonds East and Part of the Edmonds West Quadrangles Washington, 1983 United States Department of Agriculture (USDA) Web Soil Survey (WSS) Edmonds City Code Chapter 23.80 (Geologically Hazard Areas) Pacific Coast Surveys, Inc. Topographic Survey, dated October 21, 2019 Ram Engineering, Inc. Preliminary Site Plat Dear Ms. Nichols: As requested, Earth Solutions NW, LLC (ESNW) has prepared this geotechnical evaluation report for the proposed single-family residences. As part of our scope of services, we completed a subsurface exploration, in -situ infiltration testing, laboratory and engineering analyses, and prepared this written report with our findings and recommendations for the proposed project. Based on our evaluation, the proposed project is feasible from a geotechnical standpoint. 15365 N.E. 90th Street, Suite 100 • Redmond, WA 98052 • (425) 449-4704 • FAX (425) 449-4711 Select Homes, Inc. January 22, 2020 Project Description ES-7004 Page 2 The subject site is located at 8805 — 220th Street Southwest in Edmonds, Washington, as illustrated on the attached Vicinity Map (Plate 1). The site consists of one tax parcel (Snohomish County parcel number 27043000201100) covering 0.75 acres. Based on the referenced survey, the boundary lines will be adjusted to create three new parcels. The property is currently developed with a single-family residence, detached garage, and associated improvements. The subject site generally descends towards the north with total elevation change on the order of five feet or less. The subject site is bordered to the north by a single-family residence, to the east by 88th Avenue West, to the south by 220th Street Southwest, and to the west by 88th Place West. We understand the existing single-family residential structure and associated improvements will be demolished and three new single-family residential structures will be constructed. We anticipate grading activities will include cuts and fills of about two to four feet to establish the planned building alignments. However, grading plans were not available at the time this report was prepared. We understand infiltration and low impact development methods are being evaluated for stormwater management. Site improvements will also include underground utility installations. At the time this report was prepared, specific building load values were not available. However, we anticipate the proposed residential structures will consist of relatively lightly loaded wood framing supported on conventional foundations. Based on our experience with similar developments, we estimate wall loads on the order of one to two kips per linear foot and slab -on - grade loading of 150 pounds per square foot (psf). If the above design assumptions are incorrect or change, ESNW should be contacted to review the recommendations in this report. ESNW should review the final design to verify the geotechnical recommendations provided in this report have been incorporated into the plans. Subsurface Conditions As part of this geotechnical evaluation, an ESNW representative observed, logged, and sampled four test pits on December 6, 2019, excavated at accessible locations within the proposed development area, using a mini-trackhoe and operator provided by the client. The approximate locations of the test pits are depicted on the Test Pit Location Plan (Plate 2). Please refer to the test pit logs provided as an attachment to this report for a more detailed description of subsurface conditions. Representative soil samples collected at the test pit locations were analyzed in general accordance with the Unified Soil Classification System (USCS) and USDA methods and procedures. Topsoil and Fill Native topsoil was observed extending to depths of approximately 6 to 12 inches below the existing ground surface (bgs). The topsoil was characterized by dark brown color and fine organic material. Fill was encountered at test pit locations TP-1, TP-3, and TP-4 during our fieldwork, extending to depths of approximately two and one-half to five and one-half feet bgs. Earth Solutions NW. LLC Select Homes, Inc. January 22, 2020 Native Soil ES-7004 Page 3 Underlying the topsoil and fill, soil conditions at the test pit locations were observed to consist primarily of silty sand (USCS: SM). A relatively thin layer of poorly graded sand with silt (USCS: SP-SM) was observed at depth at TP-1 and TP-4 which transitioned to silty sand at depth. Overall soil relative density increased with depth, extending to the maximum exploration depth of about seven feet bgs. The native soil was generally observed in a weakly to moderately cemented condition at about four to five feet bgs. Geologic Setting The referenced geologic map resource identifies Vashon till (Qvt) across the site and surrounding areas. As reported on the geologic map resource, Vashon till typically consists of a nonsorted mixture of clay, silt, sand, pebbles, cobbles, and boulders. The till was deposited directly by ice advanced over previously deposited sediment and rocks. In addition, the referenced WSS resource identifies Alderwood-Urban land complex (Map Unit Symbol: 5) as the primary soil units underlying the subject site. The Alderwood series was formed in glacial till plains. Based on our field observations, native soils on the subject site are generally consistent with the geologic setting outlined in this section. Groundwater Groundwater seepage was not observed at the test pit locations during the fieldwork (December 2019). However, perched groundwater seepage is common in glacial till deposits, particularly during the winter, spring, and early summer months. Groundwater seepage rates and elevations fluctuate depending on many factors, including precipitation duration and intensity, the time of year, and soil conditions. Geologically Hazardous Areas Assessment As part of this geotechnical evaluation, the referenced chapter of the Edmonds City Code was reviewed. Based on our investigation and review, there are no geologically hazardous areas present on or adjacent to the site. Foundations The proposed single-family structures can be supported on conventional spread and continuous footings bearing on undisturbed, competent native soil, compacted native soil, or new structural fill. Competent native soils, suitable for support of the foundation, should be encountered beginning at depths of approximately two to three feet bgs. Where loose or unsuitable soil conditions are encountered at foundation subgrade elevations during site preparation activities, compaction of the soils to the specifications of structural fill, or overexcavation and replacement with granular structural fill will be necessary. Structural fill should consist of suitable granular soils compacted to 95 percent of Modified Proctor (ASTM D1557). Compaction of the soil to the levels necessary for use as structural fill will be difficult during wet weather conditions. Organic material exposed at foundation subgrade elevations must be removed and grades restored with structural fill. Earth Solutions NW. LLC Select Homes, Inc. ES-7004 January 22, 2020 Page 4 Provided the structures will be supported as described above, the following parameters can be used for design of the new foundations: • Allowable soil bearing capacity 2,500 psf • Passive earth pressure • Coefficient of friction 300 pcf (equivalent fluid) The passive earth pressure and coefficient of friction values included a safety factor of 1.5. A one-third increase in the allowable soil bearing capacity can be assumed for short-term wind and seismic loading conditions. With structural loading as expected, total settlement in the range of one inch is anticipated, with differential settlement of about one-half inch. The majority of the settlements should occur during construction, as dead loads are applied. Seismic Considerations The 2018 IBC recognizes ASCE for seismic site class definitions. In accordance with Table 20.3- 1 of ASCE, Minimum Design Loads for Buildings and Other Structures, Site Class D, should be used for design. In our opinion, the site susceptibility to liquefaction is negligible. The native soil relative density and the absence of an established, shallow groundwater table are the primary bases for this opinion. Drainage Temporary measures to control surface water runoff during construction would likely involve passive elements such as interceptor trenches and sumps. ESNW should be consulted during preliminary grading activities to evaluate seepage areas and provide recommendations to reduce the potential for seepage -related instability. Finish grades should be designed to direct surface water away from structures and slopes. Grades adjacent to buildings should be sloped away at a gradient of either at least 2 percent for a horizontal distance of up to 10 feet or the maximum allowed by adjacent structures. In our opinion, foundation drains should be installed along building perimeter footings. Infiltration Evaluation As indicated in the Subsurface Conditions section, native soils encountered during our fieldwork were characterized primarily as silty sand with gravel glacial till deposits. Based on the results of USDA textural analyses, the native soils were classified primarily as loamy sand with fines contents of about 12 to 22 percent. Earth Solutions NW. LLC Select Homes, Inc. January 22, 2020 ES-7004 Page 5 In -situ testing was completed in accordance with the Small-scale Pilot Infiltration Test (PIT) procedure, as outlined in Volume III, Chapter 3, Page 526 of the 2014 SMMWW. The testing was completed at a depth of approximately four feet at TP-2. The in -situ rate obtained during testing was 0.13 inches per hour. Soil Infiltration Characteristics The observed unweathered glacial till soil deposits at relatively shallow depths exhibit very poor soil infiltration characteristics. Based on the observed shallow depth to dense unweathered glacial till deposits and the results of the PIT, we do not recommend utilizing infiltration systems for the proposed development. On -site Stormwater Manaaement Pursuant to City of Edmonds stormwater management requirements, implementation of on -site stormwater BMPs are required for proposed developments in accordance with specified thresholds, standards, and lists. The intent of BMP implementation is to infiltrate, disperse, and retain stormwater runoff on site to the extent feasible. The table below summarizes our evaluation of low impact development methods, as outlined in the referenced stormwater manual, from a geotechnical standpoint. It is instructed in the referenced stormwater manual that BMPs are to be considered in the order listed (from top to bottom) for each surface type, and the first BMP that is determined to be viable should be used. For completeness, however, we have evaluated each listed BMP for the proposed surface types. BMP Viable? Limitations or Infeasibility Criteria Lawns and Landscaped Areas T5.13: Post -construction soil quality and depth (Volume V, Yes None. Chapter 5 Roofs T5.30: Full dispersion (Volume T5.30: Adequate vegetative flow paths will likely not be V, Chapter 5) Maybe available. T5.10A: Downspout full T5.10A: The unweathered glacial till soils observed at infiltration systems (Volume III, relatively shallow depths exhibit very poor soil infiltration Chapter 3) No characteristics and should be considered impermeable for design. The unweathered glacial till soils observed at relatively Bioretention (Volume V, Chapter No shallow depths exhibit very poor soil infiltration 7) characteristics and should be considered impermeable for design. T5.1013: Downspout dispersion Maybe* Adequate vegetative flow paths are likely not available. systems (Volume III, Chapter 3) Earth Solutions NW. LLC Select Homes, Inc. January 22, 2020 ES-7004 Page 6 BMP Viable? Limitations or Infeasibility Criteria T5.10C: Perforated stub -out connections (Volume III, Chapter Maybe* Water will perch on the unweathered glacial till soil. 3 Other Hard Surfaces T5.30: Full dispersion (Volume Maybe* Adequate vegetative flow paths are likely not available. V, Chapter 5) The unweathered glacial till soils observed at relatively T5.15: Permeable pavement No shallow depths exhibit very poor soil infiltration (Volume V, Chapter 5) characteristics and should be considered impermeable for design. The unweathered glacial till soils observed at relatively Bioretention (Volume V, Chapter NO shallow depths exhibit very poor soil infiltration 7) characteristics and should be considered impermeable for design. T5.12: Sheet flow dispersion T5.11: Concentrated flow Maybe* Adequate vegetative flow paths are likely not available. dispersion (Volume V, Chapter 5) * Viability to be determined by storm designer. Limitations The recommendations and conclusions provided in this geotechnical evaluation report are professional opinions consistent with the level of care and skill that is typical of other members in the profession currently practicing under similar conditions in this area. A warranty is not expressed or implied. Variations in the soil and groundwater conditions observed at the test pit locations may exist and may not become evident until construction. ESNW should reevaluate the conclusions in this geotechnical evaluation report if variations are encountered. Earth Solutions NW. LLC Select Homes, Inc. January 22, 2020 ES-7004 Page 7 Should you require additional information, or have questions, please call. Sincerely, EARTH SOLUTIONS NW, LLC .Adam Z. Shier, L.G. Senior Staff Geologist Henry T. Wright, P.E. Senior Project Manager Attachments: Plate 1 — Vicinity Map Plate 2 — Test Pit Location Plan Test Pit Logs Grain Size Distribution cc: RAM Engineering, Inc. Attention: Mr. Rob Long, P.E. (Email only) Earth Solutions NW, LLC Lynnwood _Main $freer_ � Main,Street_ _i — N Dayton Street Maple Way _ � 3 D. e Street Maple Street 210[h street Southwest Yost Park Alder Street N C Walnut Street Walnut Street SheO Q° ¢ 3 — Cedar StreetyROao' Q — v Edmonds/ Park 212 1 J� Spruce street a' Woodway Apartments spruce street a @oH,tlO =�75 High School Laurel Street >1 215th Street Southwest mondS P Pine Street 216th Street Southwest Chase Lake 216th Street Southwest A 216th Street Southwest �ol n School s Elementary o W �i 211th Street southwest m Fir Streeto s S < m m 218th street Southwest 1 3 SITE P z elm street a a_220th Street,Sohwest _ Elri �Ce 3 i > a ¢ A >222nd Street Southwest D — (� = Esperance / Park lo � Street Southw 224th � est 224th`Street Southwest s N \ Q Esperance 3 - \\ sSUis,.P et Southwest Io. I � 226th Street Southwest ^ � -2 2 26t1 WA 104 0 > c, - — - —— ; WPSLgate - v 228thStree[ Southwest - - 228[h Street Southwest Pt wood \ al a� p j ao /Nab F a" orest 54�Edmo O\\<> 230mstreetsouthwesst ^ _ Ny 237st Street Southwest ¢ r� I TI 232nd Street Southwest qr < O, Ballla( z3zndPlace Southwest ParF c g Edmonds i Fo 233rd Place southwest = r o Heights N�1 s 23om Street Southwest >al 234[h Street Southwest a' lad no K12 'c !� Madrona Lane iwesi N � 236[h Street Southwest 236[h Street Southwest 0 Madrona \ � t �G K-8 School \\ WA 99 ,we r ) 238th Street Southwest. I m 238th Street Southwest t1 238th Street Southwest t 24o11, Street southwest 240th Street Southwest 240th Street Southw7�9_ a '< �ontl WA 104 0 NORTH Reference: 00! �16' Snohomish County, Washington OpenStreetMap.org 40 NOTE: This plate may contain areas of color. ESNW cannot be responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. b.Ar, ... Vicinity Map 8805 - 220th Street S.W. Edmonds, Washington Drwn. CAM Date 12/18/2019 Proj. No. 7004 Checked AZS Date Dec. 2019 1 Plate 1 I I I I 00 00 435 -----c-------------- I TP-2 I I I I I I I I I Asphalt Driveway i I ' TP-1 —■ I I ' LEGEND I Garage ' I \ I I TP-4�\�� � I Concrete 435 I I House > - I I 22OTH STREET S.W. TP-1 Approximate Location of — ■ — ESNW Test Pit, Proj. No. ES-7004, Dec. 2019 Subject Site Existing Building NOTE: The graphics shown on this plate are not intended for design purposes or precise scale measurements, but only to illustrate the approximate test locations relative to the approximate locations of existing and / or proposed site features. The information illustrated is largely based on data provided by the client at the time of our study. ESNW cannot be responsible for subsequent design changes or interpretation of the data by others. I■ NORTH 0 25 50 100 1 "=50' Scale in Feet Test Pit Location Plan 8805 - 220th Street S.W. Edmonds, Washington NOTE: This plate may contain areas of color. ESNW cannot be ' responsible for any subsequent misinterpretation of the information Drwn. CAM Date 12/18/2019 Proj. No. 7004 resulting from black & white reproductions of this plate. Checked AZS Date Dec. 2019 Plate 2 Earth Solutions NWLLC SOIL CLASSIFICATION CHART MAJOR DIVISIONS SYMBOLS TYPICAL DESCRIPTIONS GRAPH LETTER GRAVEL AND CLEAN GRAVELS ' �' ' `� • * .0 ■� GW WELL -GRADED GRAVELS, GRAVEL - SAND MIXTURES, LITTLE OR NO FINES ■C o d o paQ Q Q np GP POORLY-GRADED GRAVELS, GRAVEL- SAND MIXTURES, LITTLE OR NO FINES GRAVELLY SOILS (LITTLE OR NO FINES) COARSE GRAINED SOILS MORE THAN 50% OF COARSE GRAVELS WITH FINES ' Q ° �° ° D a GM SILTY GRAVELS, GRAVEL -SAND - SILT MIXTURES FRACTION GC CLAYEY GRAVELS, GRAVEL - SAND - CLAY MIXTURES RETAINED ON NO. 4 SIEVE (APPRECIABLE AMOUNT OF FINES) SAND AND CLEAN SANDS SW WELL -GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO FINES MORE THAN 50% OF MATERIAL IS SP POORLY -GRADED SANDS, GRAVELLY SAND, LITTLE OR NO FINES LARGER THAN NO. 200 SIEVE SIZE SANDY SOILS (LITTLE OR NO FINES) SANDS WITH FINES SM SILTY SANDS, SAND - SILT MIXTURES MORE THAN 50% OF COARSE FRACTION S`+ CLAYEY SANDS, SAND - CLAY MIXTURES PASSING ON NO. 4 SIEVE (APPRECIABLE AMOUNT OF FINES) INORGANIC SILTS AND VERY FINE ML SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY FINE GRAINED SOILS SILTS LIQUID LIMIT AND LESS THAN 50 CLAYS CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS -u OL ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY MORE THAN 50% OF MATERIAL IS MH INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SAND OR SMALLER THAN NO.200 SIEVE SILTY SOILS SIZE SILTS LIQUID LIMIT AND CLAYS GREATER THAN 50 CH INORGANIC CLAYS OF HIGH PLASTICITY OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY. ORGANIC SILTS HIGHLY ORGANIC SOILS T' ' ' ' ' ' PT PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS DUAL SYMBOLS are used to indicate borderline soil classifications. The discussion in the text of this report is necessary for a proper understanding of the nature of the material presented in the attached logs. Earth Solutions NW TEST PIT NUMBER TP-1 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 PAGE 1 OF 1 Telephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-7004 PROJECT NAME 8805 - 220th Street S.W. DATE STARTED 12/6/19 COMPLETED 12/6/19 GROUND ELEVATION TEST PIT SIZE EXCAVATION CONTRACTOR Client -Provided GROUND WATER LEVELS: EXCAVATION METHOD AT TIME OF EXCAVATION -- LOGGED BY AZS CHECKED BY HTW AT END OF EXCAVATION -- NOTES Depth of Topsoil & Sod 6": grass AFTER EXCAVATION - L = }� H L U w Lu g TESTS Q O MATERIAL DESCRIPTION ❑ 2 Z 0 0 Q CO 0 SM 0.5 Brown silty SAND, loose, moist (Fill) TPSL 1.0 Dark brown TOPSOIL (Fill) Brown silty SAND with gravel, medium dense, moist (Fill) SM MC = 7.00% 2.5 Brown silty SAND with gravel, medium dense to dense, moist -larger gravels and cobbles encountered MC = 12.90% SM Fines = 12.00% [USDA Classification: gravelly loamy coarse SAND] 5 :.' 5.0 Gray poorly graded SAND with silt, dense, moist MC = 9.70% SP- -weakly cemented SM 6.5 -becomes dense, iron oxide staining SM :: 7.0 Gray silty SAND with gravel, dense to very dense, moist (Unweathered Till) MC = 14.60% Test pit terminated at 7.0 feet below existing grade. No groundwater encountered during excavation. No caving observed. Bottom of test pit at 7.0 feet. Earth Solutions NW TEST PIT NUMBER TP-2 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 PAGE 1 OF 1 Telephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-7004 PROJECT NAME 8805 - 220th Street S.W. DATE STARTED 12/6/19 COMPLETED 12/6/19 GROUND ELEVATION TEST PIT SIZE EXCAVATION CONTRACTOR Client -Provided GROUND WATER LEVELS: EXCAVATION METHOD AT TIME OF EXCAVATION -- LOGGED BY AZS CHECKED BY HTW AT END OF EXCAVATION -- NOTES Surface Conditions: gravel AFTER EXCAVATION - L = }� H L U 2 w Lu g TESTS Q O MATERIAL DESCRIPTION ❑ 2 Z � Q U 0 Tan silty SAND with gravel, loose to medium dense, moist SM -roots MC = 5.80% 1.5 Gray silty SAND, dense to very dense, moist (Unweathered Till) -moderately cemented MC = 10.50% MC = 11.90% Fines = 21.80% SM -infiltration test at 4' [USDA Classification: gravelly loamy coarse SAND] 5 MC = 10.10% 7.0 [USDA Classification: gravelly loamy SAND] Fines = 22.10% Test pit terminated at 7.0 feet below existing grade. No groundwater encountered during excavation. No caving observed. Bottom of test pit at 7.0 feet. Earth Solutions NW TEST PIT NUMBER TP-3 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 PAGE 1 OF 1 Telephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-7004 PROJECT NAME 8805 - 220th Street S.W. DATE STARTED 12/6/19 COMPLETED 12/6/19 GROUND ELEVATION TEST PIT SIZE EXCAVATION CONTRACTOR Client -Provided GROUND WATER LEVELS: EXCAVATION METHOD AT TIME OF EXCAVATION -- LOGGED BY AZS CHECKED BY HTW AT END OF EXCAVATION -- NOTES Depth of Topsoil & Sod 6": grass AFTER EXCAVATION - L = }� H L U 2 w Lu Co TESTS Q O MATERIAL DESCRIPTION ❑ 0- Z W � 0 Q CO 0 TPSL 0.5 Dark brown TOPSOIL (Fill) Gray silty SAND with gravel, medium dense to dense, moist (Fill) MC = 10.70% SM Fines = 16.10% [USDA Classification: very gravelly loamy SAND] 2.5 Gray silty SAND with gravel, dense to very dense, moist (Unweathered Till) -weakly cemented MC = 15.50% -iron oxide staining SM 5 65 -moderately cemented . MC = 11.30% Test pit terminated at 6.5 feet below existing grade due to refusal in very dense till. No groundwater encountered during excavation. No caving observed. Bottom of test pit at 6.5 feet. Earth Solutions NW TEST PIT NUMBER TP-4 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 PAGE 1 OF 1 Telephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-7004 PROJECT NAME 8805 - 220th Street S.W. DATE STARTED 12/6/19 COMPLETED 12/6/19 GROUND ELEVATION TEST PIT SIZE EXCAVATION CONTRACTOR Client -Provided GROUND WATER LEVELS: EXCAVATION METHOD AT TIME OF EXCAVATION -- LOGGED BY AZS CHECKED BY HTW AT END OF EXCAVATION -- NOTES Depth of Topsoil & Sod 12": grass AFTER EXCAVATION - L = }� H L U w Lu g TESTS Q O MATERIAL DESCRIPTION ❑ 2 Z 0 0 Q U 0 Dark brown TOPSOIL (Fill) TPSL 1.0 Brown silty SAND with gravel, loose to medium dense, moist (Fill) -roots MC = 15.00% -becomes dark brown to 3' SM -caving to 5.5' -wood debris 5 MC = 11.90% -charcoal 5.5 SP- " � : Gray poorly graded SAND with silt and gravel, medium dense to dense, moist SM ]]:J] 6.5 SM IL70 Gray silty SAND with gravel, dense to very dense, moist (Unweathered Till) MC = 9.10% -moderately cemented Test pit terminated at 7.0 feet below existing grade due to refusal in very dense till. No groundwater encountered during excavation. Caving observed from 3.5 to 5.5 feet. Bottom of test pit at 7.0 feet. Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 low Fax: 425-449-4711 PROJECT NUMBER ES-7004 W m W Z U- Z W Of W CL GRAIN SIZE DISTRIBUTION PROJECT NAME 8805 220th Street SW INS 111011111111111111111 iiiiiiinmiiiiiiimmiiiillism INN lmmiii 01,111111111111111111111111111111111111 INN 11111I111111111 illowililill§Ellll lism INN 11111111111111 1WI, 2111111111111111 Millillism lmmiiiiiilmmiiiiii INN 1111111 IN s GRAVEL COBBLES coarse fine SAND SILT OR CLAY coarse I medium fine Classification Cc Specimen Identification Cu TP-01 4.00ft. USDA: Brown Gravelly Loamy Coarse Sand. USCS: SM with Gravel. 1.09 20.28 i m TP-02 4.00ft. USDA: Gray Gravelly Loamy Coarse Sand. USCS: SM. • TP-02 7.00ft. USDA: Gray Gravelly Loamy Sand. USCS: SM. * i TP-03 1.50ft. USDA: Gray Very Gravelly Loamy Sand. USCS: SM with Gravel. Specimen Identification D100 D60 D30 D10 LL PL PI %Silt %Clay • TP-01 4.Oft. 19 1.238 0.286 12.0 m TP-02 4.Oft. 19 0.693 0.163 21.8 • TP-02 7.Oft. 37.5 0.579 0.15 22.1 * TP-03 1.5ft. 37.5 2.936 0.295 16.1