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City Park & Walkway Geotech report.pdfGEOTECHNICAL. REPORT 76t" Avenue West & 751 Place West Walkway Improvements Edmonds, Washington HWA Project No. 2006-171-21 Prepared for Gray & Osborne, Inc. November 16, 2007 HWAGEOSCIENCES INC. • Geotechnical Engineering • Hydrogeology • Geoenvirontnental Services - Inspection & Testing TABLE OF CONTENTS Paye 1. INTRODUCTION................:................................. ...,.1 1.1 SITE AND PROJECT DESCRIPTION.................................................................1 2. EXPLORATIONS AND GEOLOGIC CONDITIONS............................................................2 2.1 SUBSURFACE EXPLORATIONS.......................................................................3 2.2 GENERAL GEOLOGIC CONDITIONS..............................................................3 2.3 LANDSLIDE HISTORY....................................................................................3 2.4 SUBSURFACE CONDITIONS......................................................,.....................4 2.5 GROUNDWATER CONDITIONS.....................................................................5 2.6 LABORATORY TESTING................................................................................5 3. RECO1V mENDATIONS.................................................«..........,....................,...............6 31 GENERAL.......................................................................................................6 3.2 EARTH RETAINING STRUCTURES.................................................................6 3.3 PILE SUPPORTED WALKWAYS.....................................................................7 3.4 PA'VEtVIENTS...................................................................................................7 3.5 PARK DESIGN................................................................................................8 3.5.1 Stability..........................................................................................8 3.5.2 Park Drainage..............................................................................8 3.5.3 Foundation Design.......................................................................9 3.5.4 Park Pavement.............................................................................9 4.4 CONDITIONS AND LIMITATIONS ................................................................................9 LIST OF FIGURES (FOLLOWING TEXT) Figure 1 Figures 2-4 Figure 5 Figure 6 Figure 7 1 Figure S i Figure 9A & 9B Appendices Vicinity Map Site and Exploration Plan Park Property Exploration Plan Proposed Park Plan Cross Section A -A' Log of Previous Test Boring HWA 1 Boring WA -3 Inclinometer Plot Appendix A: Field Exploration Figure A-1. Legend of Terms and Symbols Used on Exploration Logs Figures A-2 - A-13 Logs of Test Borings BH -1 through BH -3 and Hand Borings HH -1 through HH -9 Appendix B: Laboratory Testing Figure B-1 Particle Size Distribution Test Results Figure B-2 Liquid Limit, Plastic Limit, and Plasticity Index of Soils (Atterberg Limits) GEOTECHNICAL REPORT WALKWAY IMPROVEMENTS 76TH AVENUE WEST AND 75TH PLACE. WEST EDMONDS, WASHINGTON 1. INTRODUCTION This report presents geotechnical recommendations for design and construction of the proposed walkway improvements to 76tb Avenue West and 75th Place West in Edmonds, Washington. The purpose of this work was to assess geotechnical conditions along the project alignment and provide recommendations for design and construction of the proposed improvements. 1.1 Site and Project Description The project is located in the Meadowdale area of Edmonds, which is located along the shoreline of Puget Sound north of the city. The area is indicated on the Vicinity Map, Figure 1. The project will include construction of a walkway along 76'x' Avenue West and 75th Place West extending from Meadowdale Beach Road north to North Meadowdale Road, with some additional improvements north to the King County Park. The project will include development of a park at the north-west corner of 75th Place West and 162nd Street SW. Three conceptual designs for the proposed improvements were developed during preliminary studies. We understand. Concept i was selected for final design and construction. Under the selected concept, the new sidewalk will be located along the east (upslope) side of the roadway from Meadowdale Beach Road north to 162nd Street SW. Cuts into the hillside will be required for the new sidewalk in much of this area. The cuts will be typically 3 to 4 feet in height but will be up to 12 feet high in some areas. From 162nd Street SW north to North Meadowdale Road the new walkway will be located on the western side of the road Since placing fill along the tog of the slope could reduce the stability of the slope and is to be avoided, the new sidewalk will be supported on small diameter pipe piles where there is insufficient existing flat area. North of North Meadowdale Road two pull-outs will be constructed on the east side of the road for vehicle parking, and one 130 -foot -long section of pile -supported walkway is planned on the west side of the road. Development of the proposed park will include regrading the site and construction of a driveway, walkways, lawn and play areas. We understand an interpretive overlook is planned adjacent to 75thPlace West. A plan of the proposed park is presented on Figure 6. November16, 2007 HWA Project No. 2006-171-21 2. l+ xPLORATIONs AND GEOLOGIC CONDITIONS 21 Subsurface Explorations Subsurface information for the project was obtained by advancing three hollow stem auger borings designated BH -1 through BH -3; nine hand borings designated HH -i through HH -9; and three DCP soundings performed in concert with hand borings HH -7 HH -8 and HH -9. Boring BH 1 was conducted by Davies Drilling Inc. using a track mounted CME -75 drill rig with a 3.25 inch OD hollow stem auger. Borings BH -2 and BH -3 were drilled by Environmental Drilling using a truck mounted B-61 drill rig with an 8 inch OD hollow stem auger. Boring BH -1 is located in the northeast section of the proposed new parr. Borings BH -2 and BH -3 are located along the proposed sidewalk alignment where a new solider pile wall will be installed on the east side of 76d' Avenue West and 75h Place West. Hand holes HH --1 through HH -6 are located along the east side of 76th Avenue West and 7S h Place West along the alignment of the proposed sidewalk. Hand holes HH -7 through HH -9 along with their associated DCP soundings are located along the west side of 75` Place west between 162IId Street West and North Meadowdale beach road. Borings were advanced either at the edge the City right of way, or in the middle of the right travel lane, as shown in Figures 24. A 2 -inch diameter ground water monitoring well was installed in BH -2 with screen from a depth of 15 to 25 feet and a silica sand filter from a depth of 12 to 30 feet. A slope inclinometer casing was installed in BH -1 after the completion of the boring. The casing was installed to a depth of 35 feet below the ground surface and was incased in cement grout. A baseline reading for future measurements was taken on October 24th 2007. Borings were located using a site map provided by Gray & Osborne inc. by measuring from existing structures shown on the base map provided. A legend of the terms and symbols used on the boring logs is presented in Figure A-1. Summary boring logs are presented in Figures A-2 through A-13. Standard Penetration tests were performed at 2.5 -foot or 5 -foot intervals in all three borings. The Standard Penetration test consists of driving a 2 -inch O.D. split -spoon sampler a distance of 18 inches into the bottom of the borehole with a 140 -pound hammer falling.30 inches. The number of blows required to drive the sampler each of three 6 -inch increments was recorded, and number of blows required to cause the last 12 inches of penetration was termed the Standard Penetration Resistance (N -value). This value is an indicator of the relative density or consistency of the soils. Whenever 50 or more blows were required to cause 6 inches of penetration, driving was stopped and the number of blows and corresponding penetration were recorded. Samples recovered from the split spoon sampler were disturbed but were representative of the soils encountered. Final Geotechnical Report 2 HWA GeoSciences Inc. Novemberi6, 2007 HWA Project No. 2006-171-21 An HWA geologist monitored the drilling and logged the borings. Soil samples were obtained from the borings at intervals of 2.5 to 5.0 feet, classified in the field, and representative portions were placed in plastic bags. These soil samples were taken to our Lynnwood, Washington, laboratory for further examination and testing. Pertinent information including soil sample depths, stratigraphy, soil engineering characteristics, and ground water occurrence were recorded on the exploration. logs. The stratigraphic contacts shown on the individual boring logs represent the approximate boundaries between soil types; actual transitions may be more gradual. The soil and ground water conditions depicted are only for the specific date and locations reported and, therefore, are not necessarily representative of other locations and times. 2.2 General Geologic Conditions Geologic information for the project site was obtained from the published geologic map for the area; Booth, D. B., Cox, B. F., Troost, K. G., and Shimel, S. A., 2004, Composite geologic map of the Sna King area: University of Washington, Seattle Area Geologic Mapping Project, scale 1:24,000. This map indicates that the surficial geology of the area consists of Pre -Fraser terrestrial deposits, overlain by Vashon-stade advance outwash, a unit of mostly clean sand with some gravel, overlain by Vashon-stade glacial till a non. -stratified and non -sorted mixture of clay, silt, sand, and gravel. The terrestrial deposits reside mainly in the northern portion of the sidewalk alignment while the till and advance deposits are seen in the southern portion of the alignment. The area is also overlain by landslide colluvium deposited by the ancient Meadowdale slide. The landslide deposits occur throughout most of the site and are surficial above the glacial and pre -glacial terrestrial deposits. 2.3 Landslide History The majority of the project alignment lies within the North Edmonds Earth Subsidence and Landslide Hazard Area, which is described in detail in a report titled "Landslide Hazards Investigation, Meadowdale Area, Edmonds, 'Washington" prepared by Roger Lowe Associates in 1979. According to the Roger Lowe Associates report, this area of Meadowdale experienced large-scale ground movement between two and three thousand years ago. This slide was approximately 3,200 feet long and up to 650 feet wide. The head scarp is easily distinguishable above 75h Place West. The cause of this large-scale earth movement is inferred to be progressive shoreline erosion by wave action; the waves eroded the toe of the slope, which over -steepened it and eventually led to land sliding. Construction of the Great Northem Railroad, which is currently owned by Burlington Northern Santa Fe, along the beach, has halted the shoreline erosion process since it armors the toe of the slope from wave erosion. Final Geotechnical Report 3 HWA GeoSciences Inc. Novemberl6, 2007 HWA Project No. 2006-171-21 1 No large-scale earth movements have been recorded for this area in modern times. However, subsequent to the ancient slide, the mass of soil within the body of the slide has experienced numerous small-scale adjustments. This type of post-slide adjustment is common and typically occurs in the form of shallow earth slumps. More recently, sliding occurred in the area in January 1997, after heavy snowfall was followed immediately by several inches of rain. Sliding occurred at several locations on the eastern side of75ih Place West and debris from one slide flowed across the street and came to rest on the western side the road. Landslides occurred throughout the Puget Sound Region at that time and are described in more detail in the paper by Gerstel et al. titled "Puget Sound Bluffs: The Where, Why, and When of Landslides Following the Holiday 1996/97 Storms" (in Washington Geology, vol. 25, no. 1, March 1997). The stud b Roger Lowe Assoc' y y g rates also indicates that the stability of the Meadowdale area is highly sensitive to groundwater levels. Improvements to local site drainage, including the installation of sewers and storm drains, have had a positive impact on the stability of the area. 2.4 Subsurface Conditions Based on the results of our exploration program, the soils underlying the project area were observed to consist of Pre -Fraser terrestrial deposits overlain by colluvial depoits and small localized quantities of fill. This observation is consistent with the sods unit mapped in the area by Booth ET. Al., by Roger Lowe Associates, and as encountered during previous drilling undertaken by HWA to evaluate the subsurface conditions for other projects in this area in the past. (HWA, 2003). Following are descriptions of the soil deposits encountered in our explorations in the order of stratigiaphic (depth) sequence by which they were deposited or placed, with the youngest unit described first. Detailed descriptions of the soils are presented in the exploration logs in Appendix A. A legend of the terms and symbols used on the boring logs is presented in Figure A-1. Summary boring logs are presented in Figures A-2 through A-13. Fill — Fill, consisting of loose to medium dense silty sand to sandy silt was identified in the locations of BH -1, 13H-3, HH -1 and HH -7 through HH -9, and ranged from 1.25 to 7 feet thick. The fill was usually identified adjacent to the road, most likely from the grading of the roadway during the initial construction. To sot -- Topsoil consisting of light brown to dark brow, silty sand with gravel was identified. in HH -1 through HH -5. In all of the hand holes the topsoil consisted of loose to medium dense surficial material with abundant roots and rootlets being present. Depths ranged from 0.5 to 2.0 feet in depth. Final Geotechnical Report 4 HWA GeoSciences Inc. Novemberl6, 2007 HWA Project No. 2006-171-21 Colluvium — Colluvium was encountered in all of the borings and in hand holes HH 2, HH -6 and HH -9. It generally consisted of very soft to medium stiff clays and silts with interspersed pieces of colluvial clays and silts, with seams of sand. The majority of the colluvium has experienced some oxidation mottling, and the seams of sand tended to be wetter than the surrounding fine grained material. Colluvial Blocks -- Colluvial blocks were encountered in Borings B11-2 and BH -3 under the softer colluvial material that overlies it. In the case of these explorations colluvial blocks refers to disturbed native soils that are denser then the overlying material, but still exhibit some variability in density and an irregularity in the soil that does not correspond with native undisturbed glacial and pre -glacial terrestrial deposits. For example in BH -3 loose poorly graded sand was encountered from 18 to 26 feet between very stiff clay and a hard laminated silt. It is not known when or how these materials were mobilized in the past, but they do exhibit some signs of disturbance. Recessional Outwas — Loose to medium dense glacial outwash consisting of light brown silty sand with gravel to gravelly sand with silt was identified in HH -3 through HH -5. The recessional outwash was encountered on the uphill (east) side of the sidewalk alignment in the area where a slope cut will occur for the new sidewalk. At the locations of TP -i and TP -16, thin layers of silty sand were encountered from 0.5 to 1.0 foot thick, which appeared to consist of recessional outwash. These soils were loose to medium dense and directly overlie the glacial till. 2.5 Ground Water Conditions Ground water seepage was encountered in borings BH -1 and BH -2 and HH -2. We expect, however, that actual ground water depths will vary depending on the season, variation in local subsurface conditions, and other factors. The project alignment is near the toe of the hillside, which is a ground water discharge area. Consequently, springs and seeps occur at numerous locations along the alignment where groundwater emerges from the ground. 2.6 Laboratory Testing Representative soil samples obtained from the subsurface explorations were returned to the HWA laboratory for further examination and testing. Laboratory tests, as described below, were conducted on selected soil samples to characterize relevant engineering properties of the on-site soils. Moisture Content of Soil: The natural moisture content of all soil samples (percent by dry mass) was determined in general accordance with ASTM D 2216. The results are shown at the sampled intervals on the test pit logs in Appendix A. Final Geotechnical Report 5 HWA Geosciences Inc. November l6, 2007 HWA Project No. 2006-171-21 r Particle Size Analysis of Soils: Selected samples were tested to determine the particle size distribution of material in general accordance with ASTM D 422. The results are summarized on Figure B-1., Appendix B, which also provides information regarding the classification of the samples and the moisture content at the time of testing. Liquid Limit, Plastic Limit, and Plasticity Index of Soils (Ai(erberg Limits): Selected samples were tested using method ASTM D 4318, multi -point method. The results are reported on the attached Liquid Limit, Plastic Limit, and Plasticity Index reports, Figure B-2. 3. REcomA 'ENDATIONS 3.1 GENERAL Construction of a walkway along 76a' Avenue West and 75th Place West will require excavation into the toe of the slope on the up-slope (eastern) side of the roadway in some areas, and placement of fill or a pile supported partially -elevated walkway on the downslope side of the road. Because placement of fill on the downslope side of the road would add to the weight of a potential landslide, reducing the stability of the slope, we recommend that filling be avoided to the extent possible. As a result, we recommend that walkways and walkway approach structures on the downslope side of the road be pile - supported wherever there is insufficient existing flat terrain. Development of the propose park will include regrading the site and construction of a driveway, walkways, lawn and play areas. We understand an interpretive overlook is planned adjacent to 75d` Place West. Because of the relatively high ground water level and the presence of an existing landslide on the property, we recommend the installation of a deep trench subdrain across the park. More detailed recommendations for park design are presented in Section 3.5. 3.2 EARTH RETAINING STRUCTURES Cuts along much of the eastern side of the alignment will be 3 to 4 feet tall. In our opinion, the most cost-effective way of retaining these shallow cuts would be with modular block walls such as Keystone blocks, or with rockeries. Block walls up to about 4 feet high (twice the depth of the block) may be made by stacking blocks without need for geogrid reinforcing. Block walls higher than twice the block depth should include geogrid reinforcing which extends back from the face of the wall a horizontal distance equal to at least 0.7 times the free-standing wall height. Geogrid reinforcing should be placed between every second layer of blocks. We recommend the use of Tensar BX1200 geogrid, or equivalent, wherever geogrid reinforcing is needed. Final Geotechnical Report 6 HWA GeoSciences Inc. Novemberl6, 2007 HWA Project No. 2006-171-21 Because of the horizontal space required for block walls, it may be desirable to use soldier pile and lagging walls where the retained height of the cut exceeds about 4 feet. Soldier pile and lagging walls would consist of 4 -inch or larger H piles set in concrete in pre -drilled holes. Lagging consisting of treated timber or precast concrete panels would be placed between the soldier piles. The size of the H -pile section would depend on the height of the wall and the horizontal spacing of the piles. Soldier piles should be designed to resist an equivalent fluid pressure equal to 55 pounds per cubic foot (pef) plus one pcf for each degree of upward inclination of the backslope. We recommend the soldier pile walls be tall enough that the backslope inclination does not exceed 2H to IV. Fill could be placed behind the soldier pile walls as necessary to flatten the slope. Soldier piles which are set into concrete in predrilled holes should penetrate below finished grade at least 1.5 times the wall's free-standing height. We do not recommend driving soldier piles because: 1) driving and maintaining pile alignment may be difficult in dense gravelly soils, 2) vibrations from pile driving can cause landslides, and 3) a concrete -filled hole provides better lateral resistance than a driven pile. Piles which are driven in place would need to extend to a depth equal to twice their free-standing height. Backfill behind the lagging should consist of I V4 -inch minus crushed rock. Soldier pile and lagging walls constructed as recommended above are typically permeable and will allow the passage of moderate amounts of seepage. Where significant volumes of water are expected, such as at existing springs, a slotted drain pipe and crushed rock backfill should be placed to intercept the flow and convey it through the wall to the storm drain system. 3.3 PILE SUPPORTED WALKWAYS Where pile support of walkways and approach structures is required, we recommend the use of 2 -inch diameter extra -strong steel pipe. When driven to less than 1 inch of penetration in 1 minute of driving with a 90 psi jackhammer, each pile should be capable of supporting 2 tons of vertical load (allowable capacity) with an adequate factor of safety. Pile installation can actually be accomplished with a backhoe -mounted compactor (hoepac), but testing to verify capacity should be done with a jackhammer. Piles will develop their bearing in native soils below any fill, and pile lengths will vary considerably_ Pile lengths could average 20 to 25 feet. 3.4 PAVEMENTS Where new street pavement is required, the pavement subgrade should be proof -rolled to verify that it is dense and unyielding. Any soft or spongy material should be replaced with 1 %4 -inch -minus crushed rock. The pavement section should consist of at least 6 inches of crushed rock (CSBC) and 3 inches of asphalt. Final Geotechnical Report 7 HWA GeoSciences Inc. Novemberl6, 2007 HWA Project No. 2006-171-21 3.5 PARK DESIGN A plan showing the park property with existing ground surface contours and the location of boring BH -1 is presented on Figure 5. A cross section through the park property showing BH -I, the previous boring HWA-3, and the assumed failure plane of the existing landslide is shown in Figure 7. The proposed layout of park facilities is shown on Figure 6. 3.5.1 Stability As indicated on Figure 5, the park property slopes downward from 750' Place West about 2H to 1 V for approximately 20 vertical feet. The site then slopes gradually to 75' Avenue West. Our previous studies indicate that a landslide exists on the north end of the park property and the adjacent property to the north. The slide is still moving as evidenced by renewed cracking in the pavement of 75h Place West. Readings from an inclinometer casing installed in the street right-of-way in front of the adjacent property to the north, shown in figure 9A and 9B indicate that the slide is about 18 feet deep at the western side of 75'h Place West. As part of the current study, HWA installed an inclinometer casing in BH -1 so that any earth movements at that location can be detected. Based on our previous studies and the existing site geometry, it appears likely that the existing slide terminates at the toe of the slope on the east side of the park and does not involve most of the park site. The results of future measurements in the two inclinometer casings will confirm or deny that assumption. Assuming that the existing landslide is confined to the north end of the slope on the eastern side of the park, the proposed park development can proceed without stabilizing the slide, providing the City is willing to accept that portions of the park as well as the roadway and the utilities within its right-of-way will continue to be affected by the sliding. Current plans for park development include placing fill along the toe of the slope below the roadway, which will tend to increase the stability of the slide but may not be sufficient to prevent future movement. A definitive stabilization design will require additional measurements in the two slope indicator casings over the course of the coming winter to determine the location of the slide plane and performing stability analyses to develop stabilization measures. That additional analysis is not within the present scope of work, however, we recommend that this additional analysis be performed and the results incorporated into the park design. 3.5.2 Park Drainage We believe the installation of a trench subdrain across the park property is necessary to remove excessive moisture for park development and maintain stability of the lower portion of the park; however, it may or may not be effective in stabilizing the existing landslide. Finn Geotechnical Report 8 HWA GeoSciences Enc. November16, 2007 HWA Project No. 2006-171-21 We recommend the construction of a trench subdrain across the park. The subdrain would consist of an 8 to 10 -foot -deep trench extending roughly north -south along the toe of the eastern slope and then turning westward rear the north property line to daylight at the western edge of the park. The approximate location of the proposed trench drain is shown on Figure 6. A 6 -inch diameter slotted plastic pipe would be placed in the bottom of the trench and the trench would be backfilled with P/4 -inch -minus crushed rock. The trench subdrain would intercept and remove ground water seepage from the site and would serve as a shear key to reduce the potential for future sliding. 3.5.3 Foundation Design Structures in the park may be supported on spread footings providing they can tolerate some settlement. The soils are capable of supporting structures at allowable bearing pressures up to 1,500 psf; however, some settlement is likely due to the loose, soft and variable nature of the soils. Structures that can not tolerate 2 inches of total and 1 inch of differential settlement should be supported on small diameter pipe piles as described in Section 3.3. Column footings should have a minimum width of 24 inches and. wall footings should have a minimum width of 18 inches. Footings should bear at least 18 inches below the lowest adjacent finished grade. 3.5.4 Park Pavement Any pavements within the park that will carry vehicular traffic should be constructed as accordance with the recommendations in Section 3.4. We recommend that pavements for walkways and trails consist of 6 inches of 1 V4 -inch minus crushed rock overlain by 1;/2 inches of asphalt. 4.0 CONDrrioNS AND LIMITATIONS We have prepared this report for Gray & Osborne and the City of Edmonds for use on this project. This data and report should be provided to prospective contractors for their bidding or estimating purposes, but the conclusions and interpretations presented should not be construed as a warranty of the subsurface conditions. Experience has shown soil and ground water conditions can vary significantly over small distances. Inconsistent conditions can occur between explorations and may not be detected by a geotechnical study. If, during future site operations, subsurface conditions are encountered which vary appreciably from those described herein, HWA should be notified for review of the recommendations of this report, and revision of such if necessary. Final Geotechnical Report 9 HWA GeoSciences Inc. ' Novemberl6, 2007 HWA Project No. 2006-171-21 We recommend that HWA GeoSciences be retained to provide monitoring of . construction sufficient to verify that the construction of retaining walls and the driving of foundation piles is accomplished in accordance with our recommendations and with the approved pians and specifications. The scope of work did not include environmental assessments or evaluations regarding the presence or absence of hazardous substances in the soil, surface water, or ground J water at this site. HWA does not practice or consult in the field of safety engineering. We do not direct the contractor's operations, and we cannot be responsible for the safety of personnel other than our own on the site; the safety of others is the responsibility of the contractor. The contractor should notify the owner if he considers any of the recommended actions presented herein unsafe. We appreciate the opportunity to be of service. Sincerely, HWA GEOSCI ENCES INC. Ralph N. Boirum, P.E. Geotechnical Engineer Principal Final Geotechnical Report 10 HWA GeoSciences Inc. Novemberl6, 2007 HWA Project No. 2006-171-21 References Roger Lowe Associates Inc., 1979, Final Report, Landslide Hazards .Investigation, Meadowdale Area, Edmonds, Washington, for the City of Edmonds, consultant report dated October 16, 1979. Gerstel et al. "Puget Sound Bluffs: The Where, Why, and When of Landslides Following the Holiday 1996197 Storms" (in Washington Geology, vol. 25, no. 1, March 1997). HWA Geosciences Inc., 2002-099-21, Geotechnical Report, Nguyen Property Slope Stabalization 16018 75`h Place West Edmonds, Washington, consultant report dated November 8, 2002. Booth, D. B., Cox, B. F., Troost, K. G., and Shimel, S. A., 2004, Composite geologic map of the Sno-King area. University of Washington, Seattle Area Geologic Mapping Project, scale 1:24,000 Final Geotechnical Report 11 RWA GeoSciences Inc. n l � IHWAGEOSCIENCES INC / SITE AND VICINITY MAP FIGURE NO. WALKWAY IMPROVEMENTS PROJECT NO. EDMONDS, WA 2006-171 Go 0'0 LEGEND HH -9 -1k HAND HOLE DESIGNATION AND APPROXIMATE LOCATION BH -3 + BOREHOLE DESIGNATION AND APPROXIMATE LOCATION HWA-3 } HWA PREVIOUSBOREHOLE DESIGNATION AND APPROXIMATE LOCATION BASE MAP PROVIDED BY.- mw, I lffiwaosa LJ Q1 M LL - LJ z H J V X LEGEND HH -9 l- HAND HOLE DESIGP BH -3 BOREHOLE DESIGNATION AND APPROXIMATE LOCATION HWA-3 HWA PREVIOUSBOREHOLE DESIGNATION AND APPROXIMATE LOCATION BASE NAP PROVIDED BY: uma mwaoscu .D A M oak 59 LxJ F-1 I. Lel z u LEGEND HH -9 HAND HOLE DESIGNATION AND APPROXIMATE LOCATIONa BH -3 + BOREHOLE DESIGNATION AND APPROXIMATE LOCATION HWA-3 HWA PREVIOUSBOREHOLE DESIGNATION AND APPROXIMATE LOCATION BASE MAP PROVIDED BY: u� p gol I I MWGWSal cn z LLJ 0-2 x LLl moi( O LLI 6.¢Lu F U1 0 r - � o z T' CL U cow E3 Cl C14 a cn z LLJ 0-2 x LLl moi( O LLI 6.¢Lu F U1 0 LEGEND r m A' (WEST) 80 70 60 x 50 LL o 40- 03020 30- 20— J u eu 40 60 80 100 (FEE EXPLORATION DESIGNATION AND SITE PLAN SYMBOL N -VALUE - (BLOWSIFOOT) STANDARD PENETRATION TEST NONSTANDARD PENETRATION TEST WATER LEVEL AT TIME OF DRILLING WATER LEVEL MEASURED IN PIEZOMETER ON THE DATE INDICATED, INFERRED GEOLOGIC CONTACT SAND PACK AND SCREEN INTERVAL BOTTOM OF BORING u. �CVw �FUVC417 �LUw�l/l-LI /blfi-/.7-Itl WALKI AND FIELD MAPS\HWA 2006-171 XSEC.DWG The; and i lines later, DRILLING COMPANY: Gregory Drilling Inc. LOCATION. See Site & Exploration Plan, Figure 2 DRILLING METHOD: Hollow -stem Auger, CME 45 C track rig DATE STARTED: 9/13/2002 SAMPLING METHOD. SPT w/ Autohammer DATE COMPLETED: 9/13/2002 SURFACE ELEVATION: 70 i feet LOGGED BY-- B. Thurber 100 5 15 1811.1 NGUYEN RESIDENCE BORING: 16108 75TH PLACE WEST HWA-3 1MGEOSCIENCES M EDMONDS, WASHINGTON PAGE:1 of 1 PROJECT NO.: 2002-099-21 Gil E. 8 BORING 2001o99.GPJ 171151(}7 m W z Standard Penetration Test 2 m N ¢ (140 lb. weight, 30" drop) = O 0 w F in A Blows per foot a� U a :2Z ff e cc Z x O UJ CO yDESCRIPTION w� a O O 0 0 10 20 30 40 SM Loose, brown, silty, fine to medium SAND, dry. Some coarse sand, trace fine gravel and organics. :_...i. = = ..i....i.._.i......... . •..- [ROAD FILL] 5-1 2-2-2 W = 5 •_ S-2 2-2-4 .WA. .......:....:....: :...:.... ....i.. ML Very !Dose, brown and gray with heavy rust mottling, very SM sandy SILT to very silty fine SAND. wet Interbedded. Some S-3 22-2 GS ......... ....:....:...•t. ' partly decomposed wood fragments. i....:....:.........r...... ...i.......... i.. 10 [EXISTING LANQSLJDE DEBRIS] � S-4 1-1-1 Q A i �....... .... ............i.. °kF. Grades to gray, silly SAND and sandy SILT with organics, : . .. . :... . :. . . .:....:.. . . : . .... . .. . : ....:.. wetS-5 ML Soft, blue -gray with brown streaks, clayey SILT with partly 1-1-2 A' - decomposed wood fragments, moist Mixed 1 swirled...... ......................................... ;•.:• appearance.-------_.----, _ / CH Lapse, ra slightly si ma to medium SAND wet. S 6a ��b 1-2-3 �....�.:........ : :....:. . Medium stiff. gray, green -gray, and brown -gray. CLAY, with .---:-•_.i..-._�_,i....:__._:.._.:-•--:....j.. micaceous fine SAND laminae, with partly decomposed --- - woody debris, moist Sand laminae at high angles, and day S-7 2-3-6 - laminations in sample tip are planar and at 60 -degree angle_ i 20 (OLD SLIDE DEEMS) 17.5 feet: Gray and darkgray,CLAY, moisL Laminae disturbed by fine angular offsets. Some dark gray """ AL :•.•.:• ...:....:....:....:....:--._:....:._. slickensides at approx. 30 degrees. CH @ 20 feet: Grades to stiff No bedding apparent, fine blocky exture. Long wood fibers caught in ti ...: = Very stiff, gray to dark gray, fat CLAY. moist Finely .... :....:......... .:......... :.... ... 25 laminated, bedding approximately horizontal. S-9 4-6-9 AL 1�-1......:............. [WHIDBEY FORMATION] :....:....i....- - ...:....i ............. 30 Includes occasional light gray laminae of coarse sift / very fine sand. S-10 6-8-11 - = 16.4 ............... -------- Borehole terminated at 31.5 feet. ............. Inclinometer casing (34nch diameter) installed to 30 feet, and backfilled with bentonite grout to 2 feel i ... _ i .. ..:. ...:....:.... i ........ -: _ _ • _ : _ - 35 Sentonite chips backfilled from 1 to 2 feel„ 10 -inch diameter .... ....:.... i .-..:.... [ ....:..... ......... flush monument set in 1 foot of concrete to surface. 40 For a proper understanding of the nature of subsurface conditions, this 0 20 40 60 so exploration log should be read in conjunction with the text of the water content (%) geotechnical report. plastic Lima 1-->iLiquid Limit Natural Water Content NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times andfur locations. 100 5 15 1811.1 NGUYEN RESIDENCE BORING: 16108 75TH PLACE WEST HWA-3 1MGEOSCIENCES M EDMONDS, WASHINGTON PAGE:1 of 1 PROJECT NO.: 2002-099-21 Gil E. 8 BORING 2001o99.GPJ 171151(}7 C) Lf7 C] to C> to P r CS1 CV (4) Hld3a O N' C7 O Ci C) o m CL O 0 CL 0 0 T O J f]. � L Z W CL 2 s wQ Z 0 r' uj >QD Q Q LLL Z O Q C) d O OO O Q Cl O Q O N 'T (31 L��l C_,[ <0 C O M+ 1 I U Gf Q O_ C d 0 d. a as L W cd EQ G O v C C) Lf7 C] to C> to P r CS1 CV (4) Hld3a O N' C7 O Ci C) o m CL O 0 CL 0 0 T O J f]. � L Z W CL 2 s wQ Z 0 r' uj >QD Q Q LLL Z v a 0 75 C 0 m co O Q O Q (V O O N a N N try M 0_0 to tV (O Hld3❑ IN Fi 0 Q O N O a F- 0 J a w z J w 0, W Q z p U as 0, ❑ z 2o � M j Q 0 TQ Q lit i F J z IW Flo 0-4 con U z 0 Appendix A Soil Boring Logs RELATIVE DENSITY OR CONSISTENCY VERSUS SPT NVALUE COHESfONLESS SOILS COHESIVE SOILS Coarse Gravel and Approximate .. GW Approximate Density N (blowslft} Relative Density(%) Consistency N (blows(ft) Lrndrained Shear Coarse sand No. 4 (4.5 mm) to No. 10 (2.0 man) Medium sand Grained Fina sand Strength (psf) Very Loose 0 to 4 0 - 15 Very Soft 0 to 2 <250 Loose 4 to 10 15 - 35 Soft 2 to 4 250 - 500 Medium Dense 10 to 30 35 - 65 MediumSSff 4 to 8 500 - 1000 Dense 30 to 50 65 - 85 Stift a to 15 1000 - 2000 very Dense over50 85 - 100 Very Stiff 15 to 30 2000 - 4000 on No. 4 Sieve amount of Tines)GC Hard over 30 >4000 USCS SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP DESCRIPTIONS Coarse Gravel and Clean Gravel .. GW Well -graded GRAVEL Coarse gravel Gravelly Soils Fine gravel 314 in to No 4 (4.5mm) Sand No. 4 (4.5 mm) to No. 200 (0.074 mm) Coarse sand No. 4 (4.5 mm) to No. 10 (2.0 man) Medium sand Grained Fina sand (li Me or no fines) SIR and Clay Smaller than No. 200 (0.D74mm) MIR Resilient Modulus GP Poorly -graded GRAVEL Soils Pocket Penetrometer n Q SG Specific Gravity TC Mora than Gravel with a GM Silty GRAVEL LIG 50% of coarse FracSon Retained Pines (appreciable on No. 4 Sieve amount of Tines)GC Clayey GRAVEL Sand and Clean Sand ,• SW Wel-graded SAND More than Sandy Soils (Rite or no fines) .•' SP Poody-graded SAND 50% Retained 50% or More Send with =' SM Silty SAND on No. of Coarse 2D0 Sieve Fines (appreciable Fraction Passing Size No. 4 Sieve amount of fines) SC Clayey SAND ML SILT L=ine SLR Grained and Liquid Limit CL Lean CLAY Soils Clay Less then 50% OL Organic SILT/Organic CLAY MH ElasticSILT 50% or More Silt Liquid Limit CH FaICLAY Passing and 50%orMore No. 200 Sieve Clay Sim OH Organic SILTIOrganic CLAY Highly Organic Soils PT PEAT r fr COMPONENT DEFINITIONS COMPONENT SIZE RANGE Boulders Larger than 12 in Cobbles 31n to 12 in Gravel 3 in to No (4.5mm) Coarse gravel 3 in to 314 in Fine gravel 314 in to No 4 (4.5mm) Sand No. 4 (4.5 mm) to No. 200 (0.074 mm) Coarse sand No. 4 (4.5 mm) to No. 10 (2.0 man) Medium sand No. 10 (2.0 mm) to No. 40 (0.42 mm) Fina sand No. 40 (0.42 mm) to No. 200 (0.074 mm) SIR and Clay Smaller than No. 200 (0.D74mm) GROUNDWATER SYMBOLS Q Groundwater Level (measured at fime of drilling) Z Groundwater Level (measured in well or open hole atter water level stabilized) COMPONENT PROPORTIONS PROPORTION RANGE TEST SYMBOLS %F Percent Fines AL Atterberg limits; PL = Plastic omit IShelby ILL. =Liquid Limit CBR California Bearing Ratio CN Consolidation DD Dry Density (pcf) DS Direct Shear GS Grain Size Distribution K Permeability MD Moisture/Density Relationship (Proctor) MIR Resilient Modulus PID Photoionization Device Reading PP Pocket Penetrometer Approx. Compressive Strength (tsi) SG Specific Gravity TC Triaxial Compression TV Torvane Approx. Shear Strength (tsf) LIG Unconfined Compression GROUNDWATER SYMBOLS Q Groundwater Level (measured at fime of drilling) Z Groundwater Level (measured in well or open hole atter water level stabilized) COMPONENT PROPORTIONS PROPORTION RANGE SAMPLE TYPE SYMBOLS ®2.0" OD Split Spoon (SPT) 5-12% (140 lb. Etammerwith 30 in. drop) IShelby Tube 30-50% --Components 3-114° OD Split Spoon with Brass Rings OSmall Bag Sample 0 Large Bag (Bulk) Sample nCore Run Non-standard Penetration Test (3.0" OD split spoon) GROUNDWATER SYMBOLS Q Groundwater Level (measured at fime of drilling) Z Groundwater Level (measured in well or open hole atter water level stabilized) COMPONENT PROPORTIONS PROPORTION RANGE DESCRIPTIVE TERMS <5% Clean 5-12% Slightly (Clayey, Silty, Sandy) 12-30% Clayey, Silty, Sandy, Gravelly 30-50% --Components Very (Clayey,Sllfy,Sandy, Gravelly) are arranged in order of increasing quantities. L NOTES, Soil classifications presented on exploration logs are based on visual and laboratory observation. Solt descriptions are presented in the following general order: MOISTURE CONTENT Densityfconsrsfertcy, color, moMer(rfany) GROUP NAM$ additions to group name (dany), mm Mrs DRY Absence of moisture, dusty, content Proportion, gradation, and angufarify ofconsftenfs, adl comments, dry to the touch (GEOLOGIC INTERPRETATION) MOIST Damp but no visible water. Please referto the discussion in the report text as well as the exploration logs for a more WET Visible free water, usualty complete description of subsurface conditions_ soil is below water table. MTA I 75th -76th Walkway improvements LEGEND OF TERMS ANDSYMBOLS USED ON Meadowdale HMCWSCM(ES 1NC. Edmonds, WA EXPLORATION LOGS PROJECT NO.: 2006-171-21 G E_ A-1 LEGEND 2006-171�1_GPJ 11115!07 DRILLING COMPANY: Davies Drilling SURFACE ELEVATION: t feet DATE STARTED: 1oliono07 DRILLING METHOD: Hallow stern Auger DATE COMPLETED: 1 011 0120 07 SAMPLING METHOD: Cat Head SPT LOGGED BY: P. Pearson LOCATION: See Figure 2 1 20.. 1 25 —i 1 35--1 = SM Loose, Brawn, slightly silly, fine to Medium SAND, moist with rots and rootlets. [FILL} Soil becomes siltier then sandy again. 15 CL e3 ........ :� rte: ..:....... r ML U 10-21-35 ....... :.... Soft. bluish gray, silly CLAY, moist. Older, black trace S-7 9-18-32 J 30 J Soft, bluish gray to brownish gray, silty CLAY, wet. Some z m U) CL Co IL z U 45 2 inch sandy layer. ---------------------- Stiff to very stiff, gray, CLAY, moist Siickenslides observed. 0 -"m W � DESCRIPTION 1 20.. 1 25 —i 1 35--1 rsonng iermmateo ax sti.a tees oelow surface. Inclinometer rasing was installed with grout from 2.5 feet above ground surface to 35 feet below ground surface. 40 Ground water observed at 10 feet and 35 feet at time of exploration. 1 45 W ut uj z Standard Penetration Test m CL � t � W t) (140 ib. weight 30" drop) z w w W LU }' A Blows per foot w a a - Q w O w H uJ n F U m N to 1Z O a y 0 10 20 30 40 50 fl w ® S-1 1„1-4 ® S-2 3-2-3:..... ..:....:....:.... 5 ® S-3 1-1-2 L ....;....�........:....:....: S-3 = SM Loose, Brawn, slightly silly, fine to Medium SAND, moist with rots and rootlets. [FILL} Soil becomes siltier then sandy again. 15 CL Loose, yellowish gray, sandy SILT, moist, trace organics. ........ :� rte: ..:....... r ML `----•-----[COLLiMUMZ-------- 10-21-35 ....... :.... Soft. bluish gray, silly CLAY, moist. Older, black trace S-7 9-18-32 organics. 30 S-8 Soft, bluish gray to brownish gray, silty CLAY, wet. Some :.....� ........:....:.... dense chunks of day also. CL Medium stiff to stiff, gray, silty CLAY, moist. Trace —� laminations observed. 45 2 inch sandy layer. ---------------------- Stiff to very stiff, gray, CLAY, moist Siickenslides observed. 0 20 40 .60 80 1D0 CH [PRE -GLACIAL TERRESTRIAL DEPOSITS] Hard, gray, CLAY with fine sand, slightly moist. Plastic Limit !---0Liquid Limit Subvertical cracks with fine sands. Horizontal laminations Natural Water Content observed. Hard, massive, gray, fine sandy, CLAY, moist to wet rsonng iermmateo ax sti.a tees oelow surface. Inclinometer rasing was installed with grout from 2.5 feet above ground surface to 35 feet below ground surface. 40 Ground water observed at 10 feet and 35 feet at time of exploration. 1 45 W ut uj z Standard Penetration Test m CL � t � W t) (140 ib. weight 30" drop) z w w W LU }' A Blows per foot w a a - Q w O w H uJ n F U m N to 1Z O a y 0 10 20 30 40 50 fl w ® S-1 1„1-4 ® S-2 3-2-3:..... ..:....:....:.... 5 ® S-3 1-1-2 L ....;....�........:....:....: S-3 4 4 5 ....�...� :...:....: :....:....:.... 15 S-5 3-5-15 ........ :� rte: ..:....... r 20 S-6 10-21-35 ....... :.... 25 S-7 9-18-32 ....................... ,>a• 30 S-8 13-27-50/5 :.....� ........:....:.... 40 45 0 20 40 .60 80 1D0 Water Content (%) Plastic Limit !---0Liquid Limit Natural Water Content 75th -76th Walkway Improvements BORING: Meadowdale BH -1 FMGEOSCIENCES INC. Edmonds, WA PAGE: 1 of 1 PZO 2006-171-21.GPJ 41fiSM7 PROJECT NO_ 2646-171-21 FIGURE- A-2 DRILLING COMPANY: Environmental Drilling Inc. SURFACE ELEVATION: d feet 1-2 inches of Asphalt over sand and gravel base course over DATE STARTED: 10/25/2007 DRILLING METHOD: Hallow Stem Auger ML Stiff, brown silt with day, moist [COLLUVIUM] Looss� branrun, fine SAND wish silt`3htoxidized moist _ DATE COMPLETED: 10125/2007 5 SAMPLING METHOD: SPT Auto Hammer CL Medium stiff, brown, SILT with sand, with trace dark orange wet oxidized silty sand seams, moist. ----------------------- Stiff, gray, SILT to clayey sift with seams of fine sand and LOGGED BY: V. Atkins ML LOCATION; See Figure 2 day, moist 10 Sand seams are wet Wood fragments in sample., U w VIML Stiff to very stiff, brown to olive brown organic SILT, moist 15 cn ¢ Standard Penetration Test ML t3Lu Z T= w (140 Ib. weight. 30" drop) F O 0 LO Lu Lu W t- 0 ut A Blows per foot CL oS a DESCRIPTION tQia u¢i a O W� u y 0 10 2D 3D Q.J iU n "' 0 SP 1-2 inches of Asphalt over sand and gravel base course over brownPoorly graded SAND with ravel fill. ML Stiff, brown silt with day, moist [COLLUVIUM] Looss� branrun, fine SAND wish silt`3htoxidized moist _ ------------------------- 5 CL Medium stiff, brown, SILT with sand, with trace dark orange wet oxidized silty sand seams, moist. ----------------------- Stiff, gray, SILT to clayey sift with seams of fine sand and ML day, moist 10 Sand seams are wet Wood fragments in sample., VIML Stiff to very stiff, brown to olive brown organic SILT, moist 15 ML Very stiff, gray to olive gray, sandy SILT, wet. [COLLUVIAL BLOCKS] Medium dense, gray, fine sandy SILT, wet W SM 20 CL Very stiff, gray, CLAY, moist— --,M----�— High plasticity. 25- 53DBoring 30— Boringwas terminated at 31.5 feet below ground surface, Ground water seepage was encountered at 15 feet below ground surface. A ground water monitoring well was installed 35 with screen from15-25 feet, and sand from 12 to 30 feet 1 40 S-1 2-45 S-2 2-2-5 S-3 3-7-8 S-4 4-4-8 5-5 5-8-8 xS-6 3-8-11 S-7 47-12 S-8 4-7-12 S-9 6-9-15 NOTE: This fog of subsurface conditions applies only atthe specified location and on the date indicated and #herefore may not necessarily be indicative of other times andlor locations. D 0 5 10 15 0 20 40 60 80 100 Water Content (%) Plastic Limit j- —0 Liquid Limit Natural Water Content 35 75th -76th Walkway improvements BORING: MT& I Meadowdale BH -2 HWAQ0SCiENCH I.NC. Edmonds, WA PAGE 1 of PZO 2008-177 21.GPd 17115101 PROJECT NO.: 2006-171-21 UU M A-3 DRILLING COMPANY: Environmental Drilling Inc. LOCATION: See Figure 2 DRILLING METHOD. Hollow Stem Auger DATE STARTED: 10/25/2097 SAMPLING METHOD: SPT Auto Hammer HATE COMPLETED: 1012512007 SURFACE ELEVATION: feet LOGGED BY: D. Coltrane 0 5- - 20- 25 20 25 30 30 =. SM 7 inches of as halt at surface- N (140 lb. weighs, 30" drop) with gravel, moist w U [FILL] ML Medium dense to dense, olive brown, silty SAND to sandy SM m z of fine SAND. [COLLUVIUM[ UJ a ' m� m Very stiff, gray to olive gray, silty CLAY with seams of gray silty fine SAND, moist SILT has organic smell. [COLLUVIAL BLOCKS] SP Loose, gray, poorly graded, fine to medium SAND with slit and 0 trace fine gravel, moist to wet. Drilling became hard at 25-26 feet BGS. U 0- m U) m ti! ik Lu E4 a w 0-:Z" V1 � DESCRIPTION y y a g O 0 5- - 20- 25 20 25 30 30 =. SM 7 inches of as halt at surface- Medium dense, alive brown to light brown, silty fine SAND (140 lb. weighs, 30" drop) with gravel, moist q. XZ [FILL] ML Medium dense to dense, olive brown, silty SAND to sandy SM SILT, with fine SAND seams; moist. Oxide mottling in seams � 10 20 30 40 5o +a of fine SAND. [COLLUVIUM[ CL C'raves!ydrillingfrom11to11.SfeefBGS----__-- ML Very stiff, gray to olive gray, silty CLAY with seams of gray silty fine SAND, moist SILT has organic smell. [COLLUVIAL BLOCKS] SP Loose, gray, poorly graded, fine to medium SAND with slit and trace fine gravel, moist to wet. Drilling became hard at 25-26 feet BGS. ML Hard, olive gray to olive brown, laminated SILT, moist SM Tt ----- Medium dense, gray, siriyfine SAND, wet Boring was terminated at 31-5 feet below ground surface. Minor ground water seepage was encountered during the exploration, but there was no standing ground water in the S5 hole after the auger was removed. NS-2 5-6-10 P1 8-3 5-8-15 S-4 11-15-16 5-5 7-9-13 S-6 4-6-10 NS-7 2-3-7 S -B 6-12-23 S -8a NS-9 7-12-12 40 --J For a proper understanding of the nature of subsurface conditions, this exploration log should be read in conjunction With the tent of the geotechnical report. NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated �_ and therefore may not necessarily be indicative of other times andlor locations. ulul Standard Penetration Test (140 lb. weighs, 30" drop) p A Blows per foot z [7 0 � 10 20 30 40 5o +a �. A. . i....._i....i.................. :....:...� �....:....:.........:....:.... 0 20 40 60 80 100 Water Content CA) Plastic Limit 1---,1— Liquid Limit Natural Water Content 10 75th -76th Walkway Improvements BORING: awl, Meadowdale BH -3 ffi%GEQSMN(TS MC Edmonds, WA PAGE. 1 of 1 PROJECT NO., 2006-171-21 FIGURE- A4 SORwr, 2006-171-21.GPJ 11/15197 5 4 I f: l• 1 f Hand hole was terminated at 4.0 feet below ground surface. { ' No groundwater seepage was encountered during the r exploration. 5 1 8 NOTE: This" Of subsurface conditions applies only at the specified location and on the date and therefore may not necessarily be indicative of other timpm nndrnr "— i— WWA I xwAGWscENMIxc 75th -76th Walkway Impr Meadowda#e Edmonds, WA bRILLING COMPANY: HWA Geosclences Inc. SURFACE ELEVATION: d fe DRILLING METHOD: Hand Bucket Auger SAMPLING METHOD: GRAB LOCATION: See Figure 2 us N D: m U EL z T p CO w to 0. U o Q. EL EL DESCRIPTION cQr, uo 0 SM Medium dense, brown, sandy SILT with gravel, roots and rootlets, moist IFILLIFOLD TOPSOIL] S-1 SM Medium dense, brown silty SAND with gravel, roots and woodchips. Less moist than above. S-2 SM Loose, yellowish brown Silty SANT] with gravel, organics and 8-3 r pieces of wood. No ground water. O 3 3 4 I f: l• 1 f Hand hole was terminated at 4.0 feet below ground surface. { ' No groundwater seepage was encountered during the r exploration. 5 1 8 NOTE: This" Of subsurface conditions applies only at the specified location and on the date and therefore may not necessarily be indicative of other timpm nndrnr "— i— WWA I xwAGWscENMIxc 75th -76th Walkway Impr Meadowda#e Edmonds, WA 1 1 1 1 1 1 1 5 --- SM Loose, dark brown. silty SAND with Gravel and organics, Moist [TOPSOIL] — — — — — — — — — — — — — — — — — — — — — — — Loose, light olive brown, silty SAND with rootlets and chunks — SM of grayish clay below 1.5'. [COLLUVIUM] —Soft o—Frve—brown, SILTwithZth—sa—nd -- — — — — — — — — — chunks of gray clay, small -VL— woodchips and bits of charcoal. Hand hole was terminated 5.5 feet Wow ground surface. Ground water seepage was encountered at 5.0 feet below ground level and stabilized at 4.7 feet below ground level after exploration. 1 7--4 1 8-1 NOTE: This log of subsurface ins applies only at the speciffed location and on the date indicated and !herefore may nal sadly be indicative of other times anow locations_ 0 20 40 60 80 100 Water Content (0/9) Plastic Limit 1----0 Liquid Limit Natural Water Content 75th -76th Walkway Improvements HAND HOLE: Meadowdale HH -2 HMGwSmNcB1-Nc-- Edmonds, WA PAGE: I of I HANDHOL 2006-17121.GPj 11M5107. PROJECT NO.; 2006-171-21 FIGUBE7 A-6 DRILLING COMPANY: HWA Geosciences Inc. SURFACE ELEVATION: SM i feet DATE STARTED: 1018/2007 SM DRILLING METHOD: Hand Bucket Auger chips. gravels are fine to medium. Soil is moist but less so DATE COMPLETED: 10!8/2007 SAMPLING METHOD: GRAB [RECESSIONAL OUTWASH] LOGGED BY: D. Coltrane LOCATION: See Figure 2 � W U Q m w -. m O N co uj a w o- iu EL v W > rn z o = r3 4 ❑ rn DESCRIPTION c¢ a g O L9 u1 ❑ 0� 1—i 2 -1 5 7 8 Hand hole was terminated at 2.25 feet below surface level. No groundwater seepagewas encountered during exploration. 0 S-1 O S-2 0 20 40 60 So 100 Water Content (%) Plastic Limit j --+ Liquid Limit Natural Water Contend NOTE: This log of subsurface conditions applies only at the specked location and on the date indicated and therefore may not necessarily be Indicative of other times and/or locations. 75th -76th Walkway Improvements HAND HOLE: BOA I Meadowdale HH -3 HMGMSMNNCES INC. Edmonds, WA PAGE: 1 of 1 PROJECT NO.: GII E- A-7 I-IANDIiOL 2006-171 11/15/07 2006-171-21 F SM Loose, light brown, silty SAND with graveland roots, moist [TOPSOIL] Loose, light yellowish brown, silty SAND with gravel and wood SM chips. gravels are fine to medium. Soil is moist but less so than above. [RECESSIONAL OUTWASH] Hand hole was terminated at 2.25 feet below surface level. No groundwater seepagewas encountered during exploration. 0 S-1 O S-2 0 20 40 60 So 100 Water Content (%) Plastic Limit j --+ Liquid Limit Natural Water Contend NOTE: This log of subsurface conditions applies only at the specked location and on the date indicated and therefore may not necessarily be Indicative of other times and/or locations. 75th -76th Walkway Improvements HAND HOLE: BOA I Meadowdale HH -3 HMGMSMNNCES INC. Edmonds, WA PAGE: 1 of 1 PROJECT NO.: GII E- A-7 I-IANDIiOL 2006-171 11/15/07 2006-171-21 F DRILLING COMPANY: HWA Geosdences Inc- SURFACE ELEVATION: =. SM #feet rootlets, moist. DRILLING METHOD: Hand Bucket Auger [fOPSOILIWEATHERED OUTWASH] ;. SM Loose, light yellowish brown silty, gravely SAND, moist DATE STARTED: 10/8/2007 µ SAMPLING METHOD: GRAB DATE COMPLETED: 10l812007 LOCATION: See Figure 2 LOGGED BY: D. Coltrane rr Lu V � Lu a ra Z W Z c ua m W J Ill Z m tart >-N a rL o Uj x O +x- ❑ DESCRIPTION N z O 009 uta 01 I 2 3 4 5 1 6 1 7 1 8 Hand hole was terminated at 2.5 feet below surface level. No ground water seepage was encountered during exploration, 0S-1 S-2 n 0 20 40 60 80 100 Water Content {%) Plastic Limit 1 0 -] Liquid Limit NOTE This log of subsurface conditions applies only at the Specified cation and on the dale indicated Natural Water Content and therefore may not necessarily be indicative of other times and/or locations. i-1 1 go, 75th -76th Walkway Improvements HAND HOLE: ��F ���readowdale HH -4 MA�SMCS INC--Ji�- Edmonds, WA PAGE: 1 of 1 HANpt-fpL 200Er171-21.GPJ 11115Ja7 PROJECT NO.: 2006-171-21 F GU : A-8 =. SM Medium dense, brown, silty SAND with gravel, roots and rootlets, moist. [fOPSOILIWEATHERED OUTWASH] ;. SM Loose, light yellowish brown silty, gravely SAND, moist [RECESSIONAL OUTWASH] Hand hole was terminated at 2.5 feet below surface level. No ground water seepage was encountered during exploration, 0S-1 S-2 n 0 20 40 60 80 100 Water Content {%) Plastic Limit 1 0 -] Liquid Limit NOTE This log of subsurface conditions applies only at the Specified cation and on the dale indicated Natural Water Content and therefore may not necessarily be indicative of other times and/or locations. i-1 1 go, 75th -76th Walkway Improvements HAND HOLE: ��F ���readowdale HH -4 MA�SMCS INC--Ji�- Edmonds, WA PAGE: 1 of 1 HANpt-fpL 200Er171-21.GPJ 11115Ja7 PROJECT NO.: 2006-171-21 F GU : A-8 DRILLING COMPANY: HWAGeosciences Inc. SURFACE ELEVATION: =. SMLoose, t feet DATE STARTED. 1018!2007 DRILLING METHOD: Hand Bucket Auger [TOPSOIL] SM DATE COMPLETED: 101612007 SAMPLING METHOD: GRAS andcobbles. Moist LOGGED BY: D. Coltrane LOCATION: See Figure 2 Loose, very light yellowish brown, silty, gravely SAND. Sand SM is fine, gravel is coarse. Soil becomes less gravely below 3.0 feet moist, to V? LU LU U EL in LLir m _U Q z N h in (Ij Lu a � 2 U.1 x Qfn x DESCRIPTION v¢j co a- n p 0 1 2 1 3- 1 4- 1 5- 1 6- 1 7- Hand hole was terminated at 5.0 feet below surface level. No ground water seepage was encountered during exploration. n S-2 NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times andlor focations. r0 F1 1 I—z 1 —4 1 —8 0 20 40 60 80 100 Water Content (°/u) Plastic Unit ! 0 Liquid Limit Natural Water Content 75th -76th Walkway Improvements HAND HOLE: Meadowdale HH -5 1Z►r GE0SMNC3 INC. Edmonds, WA PAGE: 1 of 1 PROJECT NO.: 2006-171-21 FG A-9 HANDHOL 2006-171-21.GPJ 11116M7 =. SMLoose, very dark brown, silty SAND with organic maieriat, moist. [TOPSOIL] SM Loose, right yellowish brown, gravely SAND with silt andcobbles. Moist MCESSIONAL OUTWASM Loose, very light yellowish brown, silty, gravely SAND. Sand SM is fine, gravel is coarse. Soil becomes less gravely below 3.0 feet moist, Hand hole was terminated at 5.0 feet below surface level. No ground water seepage was encountered during exploration. n S-2 NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times andlor focations. r0 F1 1 I—z 1 —4 1 —8 0 20 40 60 80 100 Water Content (°/u) Plastic Unit ! 0 Liquid Limit Natural Water Content 75th -76th Walkway Improvements HAND HOLE: Meadowdale HH -5 1Z►r GE0SMNC3 INC. Edmonds, WA PAGE: 1 of 1 PROJECT NO.: 2006-171-21 FG A-9 HANDHOL 2006-171-21.GPJ 11116M7 DRILLING COMPANY: HWA Geoscrances Inc. SURFACE ELEVATION: DRILLING METHOD: Hand Bucket Auger SAMPLING METHOD: GRAB LOCATION: See Figure 2 t feet DATE STARTED: 1o/8/2007 DATE COMPLETED: 10/8/2o07 LOGGED BY: D. Coltrane N W U uj ci a. ¢ G 4j J� J O Z gul Q w #= m y Lu a s a w x nl a a 4 rUJJ m rn =$ DESCRIPTION rn v� W 0 8 F O W U a 0 Loose -medium dense, light alive gray, sandy SILT with 0 organics. Soli was clumpy whit some debris, moist. [COLLUVIUM] S-1 1 ML Solt, light olive gray, silty CLAY. Chunks of silly sand, pieces 2 Of Wood. and mots, moist S-2 2 3 3 CL Loose, light gray to yelloufish brown, silly CLAY, moist ML 4 4 5 S_3 5 S Hand hole terminated at 5-5 feet below surface level. No 6 ground water seepage was encountered during exploration. 7 7 Et 6 0 20 40 s0 80 900 Water Content (%) Plastic Limit ' a Liquid Limit Natural Water Content NOTE This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. 75th -76th Walkway Improvements HAND HOLE: BOIL Meadowdale HH -6 MAGMSCUNM INC. Edmonds, WA PAGE: 1 Gf 9 HANOHpL 20x6-t7i-2t.GPJ 11/15To7 ..PROJECT NO.: 2006-171-21 FIGURE: A-1 D DRILLING COMPANY: HWA Geosdences Inc. SURFACE ELEVATION: t feet 2- DATE STARTED: 1011912007 DRILLING METHOD: Hand Bucket Auger 2 Piece of old asphalt at 2.25 feet below ground surface._ DATE COMPLETED: 10/1912007 SAMPLING METHOD: GRAB SP Medium dense, gray gravelly fine to medium SANT] with silt, D S-2 •: LOGGED BY: D. Coltrane LOCATION: See Figure 2 3 OLD TOPSOIL] A Hand hole was terminated at 3.0 feet below ground surface. 4 �7 to Of Lu 4 a. caz 3 Z t t to I � ¢ Non -Standard Penetration Resistance O z v� 5 tu p (17.8 lb. weight, 22.5" drop) m F. m U)Da._ a. h I1! Z 2 X W ai $ --z L CL DESCRIPTION m r¢n - p (D Q 0 = SMLoose, olive brown silty SAND with gravel, roots and rootlets 10 0 11 present, moist. 11 A' 12 1 [FILLI 12 13 13 14 75th -76th Walkway Improvements HAND HOLE: HH-7 Meadowdale HMVWSMNCFS INC. Edmonds, VITA PAGE: 1 of 1 PROJECT NO.. 2Q©6-171-21 FIGURE". A-11 ftANONOL 2008-17121-GPd 11115107 2- 2 Piece of old asphalt at 2.25 feet below ground surface._ 3 SP Medium dense, gray gravelly fine to medium SANT] with silt, D S-2 •: roots and rootlets, moist 3 OLD TOPSOIL] A Hand hole was terminated at 3.0 feet below ground surface. 4 No ground water seepage was encountered during the exploration. 4 L' 5 6 7— -7 $ L 4 g 10 10 11 A� 11 A' 12 ' ;A 12 13 13 14 14 15 15 0 20 40 SO 80 100 Water Content (%) Plastic Limit 1--0 Liquid Limit Natural Water Content NOTE: This fog of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times andfor locations. 75th -76th Walkway Improvements HAND HOLE: HH-7 Meadowdale HMVWSMNCFS INC. Edmonds, VITA PAGE: 1 of 1 PROJECT NO.. 2Q©6-171-21 FIGURE". A-11 ftANONOL 2008-17121-GPd 11115107 DRILLING COMPANY, HWA Geosciences lilt. SURFACE ELEVATION: SM t feet DATE STARTED_ 10/19/2007 DRILLING METHOD: Hand Bucket Auger IFILL] Loose, brown, silty SAND witi3 gravel, burnt wood bits, roots, 4 SAMPLING METHOD: GRAB GATE COMPLETED: 10H912007 LOCATION: See figure 2 LOGGED BY. D. Coltrane V' x LU u °' Lu Z Z Q Non -Standard Penetration Resistance O X O os u1 to F (17.611). weight, 22.6" drop) ED IL U w nJ.. (L N Z W D .� N DESCRIPTIONy ua o 0- T O Q Iz- W 0 1 z 6 7 0 0 A: 1 O S-1 Ai and rootlets, moist -2 iO LD TOPSOILi Hand hole was terminated at 3.2 feet below ground surface No groundwater seepage was encountered during the exploration. NOTE This log aFsubsurface conditions applies only atthe specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations - A= 2 :A: 3 4 A. �...........'33 s 1 s 13 14 0 20 40 60 80 100 15 Water Content (%) Plastic Limit [--0 Liquid Limit Natural Water Content MWA I 75th -76th Walkway Improvements HAND HOLE: Meadowdale HH -8 fMGEOSCffKCES INC. Edmonds, WA PAGE: 1 of 1 PRDIECTNo.: 2(}U6-171-21 FIC E: A- HANOg01. 2006-171-21.>SPJ 91/15/07 12 SM Loose, light brown, silty SAND with gravel, roots and rootlets, moist IFILL] Loose, brown, silty SAND witi3 gravel, burnt wood bits, roots, SM 0 0 A: 1 O S-1 Ai and rootlets, moist -2 iO LD TOPSOILi Hand hole was terminated at 3.2 feet below ground surface No groundwater seepage was encountered during the exploration. NOTE This log aFsubsurface conditions applies only atthe specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations - A= 2 :A: 3 4 A. �...........'33 s 1 s 13 14 0 20 40 60 80 100 15 Water Content (%) Plastic Limit [--0 Liquid Limit Natural Water Content MWA I 75th -76th Walkway Improvements HAND HOLE: Meadowdale HH -8 fMGEOSCffKCES INC. Edmonds, WA PAGE: 1 of 1 PRDIECTNo.: 2(}U6-171-21 FIC E: A- HANOg01. 2006-171-21.>SPJ 91/15/07 12 Hand hole was terminated at 11.25 fee below ground surface. Minor groundwater seepage from the excavation wells was observed during the exploration, — Sm -\1.5 inches of Beauty Bark on surface. Loose to medium dense, olive brown. silty SAND with gravel, A' roots and rootlets, moist pieces of plastic and cemented soils present A (COLLUVIUMIFILL) T. ML Soft, to loose, layers of olive brown, sandy SILT with trace A SM gravel, mottled olive brown fine silly SAND with rootlets, and :A: grayish brown sandy SI LT with trace gravel, roots, rootlets, -A and pieces of burnt wood present moist A ICOLLUVIUrq Hand hole was terminated at 11.25 fee below ground surface. Minor groundwater seepage from the excavation wells was observed during the exploration, ()TF— This log OF subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. 7 8 12 13 . . . . . ... . . I L-15 0 20 40 60 80 100 Water Content (%) Plastic Limit 1 0 Liquid Limit Natural Water Content 75th -76th Walkway Improvements HAND HOLE: T1, . Meadowdale HH -9 HMGE0SMNCB1NC Edmonds, WA PAGE: I of I HANOMOL 200s-171-21.GPJ 11n5f07 PROJECT NO-- 2006-17121 FIGURE' A-13 A' A A :A: -A S-4 A • L A: ................... A A A ()TF— This log OF subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. 7 8 12 13 . . . . . ... . . I L-15 0 20 40 60 80 100 Water Content (%) Plastic Limit 1 0 Liquid Limit Natural Water Content 75th -76th Walkway Improvements HAND HOLE: T1, . Meadowdale HH -9 HMGE0SMNCB1NC Edmonds, WA PAGE: I of I HANOMOL 200s-171-21.GPJ 11n5f07 PROJECT NO-- 2006-17121 FIGURE' A-13 Appendix B Geotechnical Laboratory Testing [n N cc } 0 NrD^^¢ LOS J o CN � W f_�f_�s����■� o M to Cp f•f•f•f•�f•f•f•f•f• a c vis a� N [V co o O o O co r �� 0. 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