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HomeMy WebLinkAboutWWP272109 (16)Golder Associates Inc. 18300 NE Union Hill Road, Suite 200 Redmond, WA 98052-3333 Telephone (425) 883-0777 Fax (425) 882-5498 �Bolder Associates SUBSURFACE INVESTIGATION AND GEOTECHNICAL ENGINEERING REPORT FOR THE HIGATE SEWER PROJECT RENTON, WASHINGTON Prepared for: City of Renton Planning/Building/Public Works Department 1055 South Grady Way Renton, Washington 98055 a" �� �o r Shawn L. McNamara Staff Geological Engineer January 12, 2000 Submitted by: \\p,RD D. 4 Golder Associates Inc. �G of WAS 49 18300 NE Union Hill Road, Suite 200 Q ���`°� Xr Redmond, Washington 98052 CO 6_" ° 1 EXPIRES / O — Richard D. Luark, P.E. Associate Engineer WI 993-1606.300 mizmu.da OFFICES IN AUSTRALIA, CANADA, GERMANY, HUNGARY, ITALY. SWEDEN, UNITED KINGDOM, UNITED STATES January 12, 2000 i 993-1606.300 TABLE OF CONTENTS Page No. 1. INTRODUCTION 1 1.1 Purpose and Scope of Services 1 1.2 Project and Site Description 1 2. GEOTECHNICAL INVESTIGATIONS 3 2.1 Field Investigations 3 2.2 Laboratory Testing 3 3. SUBSURFACE CONDITIONS 4 3.1 General 4 3.2 Geologic Setting 4 3.3 Soil 4 3.4 Groundwater 6 4. ENGINEERING RECOMMENDATIONS 7 4.1 General 7 4.2 Trenched Excavations 7 4.3 Trenchless Excavations 7 4.4 Liquefaction 8 4.5 Trench Backfill Materials 9 4.5.1 Reuse of Construction Spoils 9 4.5.2 Subgrade Preparation 9 4.5.3 Pipe Bedding 9 4.5.4 General Trench Backfill 9 4.6 Post -Construction Settlements and Construction Observation 10 5. CONSTRUCTION CONSIDERATIONS 11 5.1 Temporary Construction Surfaces 11 5.2 Dewatering 11 5.3 Erosion Control 11 5.4 Restoration 12 6. USE OF THIS REPORT 13 LIST OF FIGURES Figure 1 Site Location Map Figure 2 Site and Exploration Plan LIST OF APPENDICES Appendix A Boring Logs Appendix B Laboratory Testing Golder Associates ' January 12, 2000 1 993-1606.300 ' 1. INTRODUCTION 1.1 Purpose and Scope of Services The City of Renton retained Golder Associates Inc. (Golder) to provide geotechnical consulting services for the proposed sewer line, located in North Renton, east of 405 near the Kennydale Hill area (Figure 1). The purpose of the activities described in this report was to characterize the subsurface geologic conditions, provide general ' geotechnical conclusions and recommendations and guidelines related to the construction of the sewer line including trenches technology recommendations, and criteria for restoration of the disturbed areas. Golder's geotechnical work activities consisted of subsurface and engineering analyses, performed in accordance with our proposal dated August 5,1999. This report presents the results of the field investigations and provides geotechnical design criteria for the project. 1.2 Project and Site Description ' We understand that the City of Renton is planning a new 8-inch-diameter sanitary. sewer line in a residential area of North Renton. The new line would allow elimination of an existing pump station and force main. The sewer line would run from an existing MH at Jones Ave NE, due east across a vegetated utility easement and drainage ditch, then due south to NE 20'n Street, and west up 20"' street about 23 feet to an existing MH. The total length of each segment is summarized below. Segment Length (ft.) East-West from Jones Ave. 409 South to NE 20`h St. 612 NE 201h St. 23 TOTAL LENGTH 1,044 The proposed sewer project is located in North Renton, east of 405 near the Kennydale ' Hill area. The sewer line is divided into three segments as indicated above. East-West From Jones Avenue ' This section of the sewer alignment runs from station 1+00 to 5+00. From station 1+00 to 2+00 the line travels east underneath Jones Ave NE into an undeveloped lot with minimal grass and weed cover before hitting a series of trees near 2+00. Just beyond the trees at the back of the undeveloped lot the line crosses under a drainage ditch near station 3+00. From station 3+00 to 5+00 the line travels through a sparsely wooded area covered with blackberry bushes. At station 5+00 the line makes a 90-degree turn ' south. 1 Golder Associates January 12, 2000 2 993-1606.300 There is little to no topographic relief between station 1 +00 and 3+00 except for the sharp drop into the drainage ditch. From station 3+00 to 5+00 there is approximately 10 feet change in elevation as the site slopes up to the east. The soil cover above the sewer line between station 1+00 and 5+00 varies from approximately 3 to 14 feet respectively. South to NE 200' Street This section of the alignment runs from station 5+00 to 11+00. From station 5+00 to 6+00 the line travels south under a thick cover of blackberry bushes. Within the blackberry bushes there are remains of 2 old cars and a camper from the residence nearby. From station 6+00 to 7+00 the line continues south beneath the cover of thick blackberry bushes and beneath the remains of an old decaying barn. From station 7+00 to 8+00 the line passes beneath an increasing thickness of blackberry bushes and alongside the residence at 3201 NE 20' Street. It is also at this point that the soils directly at the surface become increasingly soft and the depth to groundwater is significantly decreasing (wetlands). From station 8+00 to 10+00 the line passes beneath several blackberry bushes rooted within the wetlands. The groundwater table in this area is extremely high and the soil is almost too soft for foot travel. From 10+00 to 11+00 the line passes along side the residence located at 3202 NE 20' Street and into a manhole in the middle of NE 20' Street. The blackberry bushes are not present in this area. There is a row of poplars running parallel to the line up to NE 20' Street. The site slopes gently downward to the south along the line between stations 5+00 and 11 +00 with a topographic relief of approximately 5 feet. The soil cover above the proposed sewer line, between station 5+00 and 11+00, varies from approximately 14 to 4 feet respectively. NE 20'h Street From the manhole in the middle of NE 20' Street the line continues 23 feet to the west underneath NE 20`s Street to an existing manhole. NE 20' Street rises steadily to the east toward the existing manhole with a topographic relief of approximately 0.28 feet. The soil cover above the 23-foot run down NE 20' Street is approximately 5.5 feet. IGolder Associates January 12, 2000 3 993-1606.300 I 2. GEOTECHNICAL INVESTIGATIONS 2.1 Field Investigations Field investigations including six test borings (BH-1, BH-2, BH-3, BH-4, BH-5, and BH-6) were conducted on October 4,1999. The exploration locations are shown on Figure 2. Golder's test borings were drilled with a convertible trailer mounted/skid mounted, B-24 drill rig. In order to complete borings within the wetland area the rig was taken off the trailer and pulled to the drilling locations by a dozer. Boretech provided the drill rig and crew, while the dozer was provided by Northwest Excavating, both under subcontract to Golder Associates. Drilling and sampling of soils were performed in accordance with Golder Technical Procedure TP-1.2-5, "Drilling, Sampling, and Logging of Soils". Standard Penetration Tests (SPT) were performed at 5-foot intervals using a standard two-inch diameter split spoon sampler driven by a 140-pound hammer falling a distance of 30 inches, in accordance with ASTM D-1586. A Golder field geologist examined and logged the soil from the borings and recorded the groundwater conditions. The soil samples were classified in accordance with Golder Technical Procedure TP-1.2-6, "Field Identification of Soil", which is summarized on the Soil Description Index in Appendix A. All samples were placed in plastic jars and returned to our Redmond, Washington, laboratory for further classification and testing. At the completion of drilling, all of the borings were backfilled with bentonite chips and cuttings to just below the ground surface. 2.2 Laboratory Testing Geotechnical laboratory index testing was performed on selected samples from the borings. Testing consisted of grain size and moisture. Detailed test results are presented in Appendix B and on the boring logs. L Golder Associates IJanuary 12, 2000 4 993-1606.300 ' 3. SUBSURFACE CONDITIONS 3.1 General The summary boring logs are presented in Appendix A. Pertinent information including I depths, stratigraphy, soil engineering characteristics, and groundwater occurrence were recorded and summarized. The stratigraphic contacts indicated on the summary logs represent the approximate boundaries between soil types. It should be noted that soil 1 conditions are accurate only at the location of drilling and may vary between boreholes. 3.2 Geologic Setting The project is located in the vicinity of the eastern shore of Lake Washington in the Puget Sound region of Washington State. The recent geologic history of Puget Sound was dominated by the influence of glaciers. Nearly the entire Puget lowland is covered by deposits from the Pleistocene Glaciers, the most recent of which receded ' approximately 13,500 years ago. The most recent glaciation, named the Vashon, deposited soil units consisting of lacustrine silts and clays, advance outwash sand, till and recessional outwash. These deposits, and the weathered soils derived from them, make up nearly all of the near -surface soils on the slopes and higher elevations around Lake Washington. The project area is dominated by two of these glacial deposits, recessional outwash sand and till, with smaller amounts of peat and man -placed fills. 3.3 Soil ' Based on the soil conditions encountered in the borings, the stratigraphy is quite variable across the site. In general, the site appears to be underlain by layer of loose to very dense fill or in some locations peat, overlying deposits of loose to compact fine to 1 coarse recessional outwash and very dense glacial till. Soil units encountered in our borings are summarized below: • FILL: Approximately 2.5 feet of fill was encountered in BH-2, 3 feet in BH-3, and 8.0 feet in BH-6. The fill observed in BH-2 and BH-3 was loose silty sand with trace gravel and organics. This fill was most likely imported in the mid 1900s when the site was reported to be used as a horse pasture. The fill observed in BH-6 was a loose to compact silty sand with trace gravel and organics with significant mottling and iron staining. Since BH-6 is located in the shoulder of Jones Avenue, this fill can most likely be attributed to a regrade or filling in of a Idrainage ditch when the road was put in. • PEAT: Approximately 3 feet of peat was encountered in BH-4 and 3.5 feet in 1• BH-5. In our borings the peat was generally soft, organic, fibrous, clayey silt, with roots and wood fragments. The peat does not seem to be continuous across the alignment. It was found only within the wetland area from station 7+00 to 11 +00. 1 Golder Associates January 12, 2000 5 993-1606.300 RECESSIONAL OUTWASH: Recessional outwash is a fluvial deposit laid down by meltwater from a stagnating or retreating glacier. In our borings the recessional outwash was generally a loose to compact, fine to coarse sand with trace to some silt. The recessional outwash was encountered in BH-1 from the surface to 16 feet. The recessional outwash was encountered in BH-2 below the upper fill from 2.5 to 8 feet. The recessional outwash was encountered in BH-3 below the upper fill from 3 feet to the end of the boring at 14 feet. The recessional outwash was encountered in BH-4 below the upper peat from 3 to 11 feet. The recessional outwash was encountered in BH-5 below the upper peat from 3.5 feet to the end of the boring at 14 feet. The recessional outwash was encountered in BH-6 below the upper fill from 8 feet to the end of the boring at 14 feet. Recessional outwash will likely be encountered at the proposed pipeline elevation intermittently from about 1+00 to 5+00, and consistently from about 5+00 to the end of the alignment at 11+00. We encountered groundwater in this unit above the proposed pipeline elevations in BH-3, BH-4, BH-5, and BH-6. TILL: Till is an unsorted, nonstratified, homogeneous mixture of gravel, sand, silt and clay deposited beneath, or adjacent to a glacier. In this region, it is typically dense to very dense due to past consolidation by the weight of thick overlying glacial ice. In our borings the till was generally a very dense, silty fine to coarse sand with little to some gravels. Although not encountered in our borings, till commonly contains cobbles and boulders. In addition, till occasionally contains discontinuous lenses of sand which commonly hold water. These lenses can initially produce moderate groundwater flow when intercepted, but the flow typically decreases rapidly with time as the water is drained from the sand lens. The glacial till was encountered in BH-1 below the recessional outwash from 16 feet to the end of the boring at 19 feet. The glacial till was encountered in BH-2 below the recessional outwash from 8 feet to the end of the boring at 14 feet. The glacial till was encountered in BH-4 below the recessional outwash from 11 feet to the end of the boring at 14 feet. Since these borings were terminated in the till, the total thickness was unknown but the till appears to be continuous along the alignment. Although the glacial till was not encountered in BH-3, BH-5, and BH-6, the contact between the recessional outwash and the till varies in depth across the site indicating that the till most likely would have been encountered if the borings had been deeper. Glacial till will likely be encountered at the proposed pipeline elevation intermittently from about station 4+00 to station 5+00. We encountered groundwater in this unit above the proposed pipeline elevations in BH-1 and BH-2. Golder Associates January 12, 2000 6 993-1606.300 I n 3.4 Groundwater Groundwater was encountered at the time of drilling (ATD) and in the borings as follows: • Boring BH-1 at a depth of 8 feet below the surface (ATD). • Boring BH-2 at a depth of 3 feet below the surface (ATD). • Boring BH-3 at a depth of 2.5 feet below the surface (ATD). Boring BH-4 at a depth of 1 foot below the surface. This area was very wet and soft at the surface. • Boring BH-5 at a depth of 1.5 feet below the surface(ATD). Even though this boring was located adjacent to the road (NE 20' Street), this area was very wet at the surface. • Boring BH-6 at a depth of 4.5 feet below the surface (ATD). The water table encountered was interpreted to be perched on top of the relatively impermeable glacial till that was found in our borings or inferred below the recessional sand layer. Since the water levels were measured during drilling, the actual water table may be slightly different, and could vary seasonally. In particular, the water table may be closer to the ground surface during the winter and early spring. Between station 7+00 to 11+00, the water table is likely above the existing ground surface during the winter and early spring. Golder Associates January 12, 2000 7 993-1606.300 ' 4. ENGINEERING RECOMMENDATIONS ' 4.1 General Based on our subsurface explorations, the proposed project appears feasible from a ' geotechnical standpoint. The bottom of the sewer trench excavation as proposed is expected to be located in either loose to compact recessional outwash sands or dense -to - very -dense glacial till. Based on the preliminary plans provided to Golder, trenchless ' technology is proposed to advance the sewer line between stations 2+35 to 2+70, as a small drainage ditch/stream is located at about station 2+55. ' The main geotechnical issues at this site pertain to a high groundwater table combined with loose/soft soils. Temporary dewatering will be required during construction of the sewer line. Also, due to the soft ground conditions, a working surface will be required to support construction traffic. 4.2 Trenched Excavations 1 Provided temporary dewatering of the saturated recessional sands is accomplished, it is our opinion that the entire sewer line can be installed using standard trench -box ' excavations. Due to the soft nature of the ground surface, a working surface will be required to support construction traffic, as outlined in the construction section of this report. The excavation ahead of the trench box should be limited to the minimum ' necessary to complete the work and backfilling should follow immediately behind the box. Due to the presence of loose to compact recessional sands, combined with a high water table, sloughing, overbreak and raveling of the trench sidewalls should be 1 anticipated. The contractor should be responsible for dewatering of groundwater to control sidewall 1 sloughing, heave of the bottom of the trench and to maintain a dry excavation. Dewatering design criteria are contained in Section 5.2 of this report. 4.3 Trenchless Excavations In order to minimize disturbance of the small stream at station 2+50, trenchless methods may be used. Based on the size of the proposed sewer line, the most suitable methods for installation of this sewer may include horizontal bores with steel -liner ' jacking and microtunneling. Although trenchless methods offer distinct advantages in terms of minimizing disruption to the stream/drainage ditch, disturbance greater than trenching should be anticipated in the vicinity of the jacking and operating pits. Steel ' liner jacking is likely the most cost-effective method for installing the sewer beneath the stream. ' Due to the high groundwater table and loose nature of the recessional sands, combined with a fairly shallow invert, microtunneling appears to be marginal at this site. Special drilling construction procedures and drilling muds would likely be required if 1 Golder Associates January 12, 2000 8 993-1606.300 iJ Ll D microtunneling is attempted. The only advantage of trenchless installation of the sewer line is minimizing the disturbance to the wetlands present at the site. However, in the proposed alignment, manholes are spaced at approximately 400 feet, and installation would require disturbance to the wetlands for installation of the manholes. The manholes would provide logical locations for operating pits for either jacking or microtunneling. Based on our explorations completed for this study, glacial till will likely be encountered at the proposed pipeline elevation intermittently from about station 4+00 to station 5+00. Encountering till could negatively impact tunneling or jacking in two ways: 1. Boulders that may be present in the till could provide construction problems, ranging from slowed production to borehole obstruction. 2. The change in hardness at a geologic contact (loose, saturated recessional sands/very dense glacial till) may tend to deflect the auger or tunneling machine from its intended alignment. If trenchless excavation methods are used, bids should include contingencies for 1 encountering boulders in the glacial till. We would expect groundwater to be encountered above the pipe invert elevation over the entire alignment. ' Within the saturated recessional sand, some ground loss may occur if good microtunneling construction practices are not followed or if liners are not jacked in advance or concurrently with the excavation face. The contractor should be responsible for control of settlement and in particular for ensuring that any settlements that occur do not affect adjacent utilities. Some form of drop shaft will need to be excavated in order to construct the manholes and to provide a staging area for microtunneling equipment. At locations where a staging area for tunneling is required, the likely minimum diameter of the drop shaft will probably be about 12 feet. The contractor should anticipate that dewatering would be required over the majority of the alignment. We expect that active dewatering measures (e.g., wellpoints) may be necessary to dewater the excavation. 4.4 Liquefaction Loose to compact granular soils below the water table can liquefy during a seismic event, causing damage to utilities buried in such soils due to lateral spreading and ground settlement. The pipe and base of the manholes will be below the permanent water table over much of the alignment. The borings indicate that loose to compact sands will be present below the proposed pipe invert, except around stations 3+00 to 4+00, where our boring at station 3+50 encountered glacial till slightly above the pipe invert. During the design earthquake event (7.5 magnitude), the saturated recessional sands are considered susceptible to liquefaction. The consequences of liquefaction are ' that the pipeline may displace or float during liquefaction. Liquefaction can be mitigated. However, the associated cost is typically greater than replacement for a sewer line of this size. IGolder Associates January 12, 2000 9 993-1606.300 45 Trench Backfill Materials 4.5.1 Reuse of Construction Spoils In general, the outwash sands excavation spoils can be reused as trench backfill. However, materials with high silt contents (i.e., tills and the fill materials), typically can only -he used -for trench-backfill-during-the drier summer month when the moisture can be controlled. The organic materials (i.e., peats), should not be used for trench backfill. 4.5.2 Subgrade Preparation ' In general, provided that the site is properly dewatered, we would expect that the undisturbed native site soils will provide adequate subgrade support. Loosened or disturbed material should be removed from the trench bottom prior to the placement of the pipe bedding material. Areas which contain loose or soft materials at the pipe or manhole invert should be over -excavated and replaced with crushed rock or other suitable fill material. 4.53 Pipe Bedding rPipe bedding material should be placed beneath the pipe and within the pipe zone in accordance with "Pipe Bedding for Sanitary Sewers" as adopted by the City of Renton. ' Bedding above and below the pipe should be hand tamped with several passes of a vibrating plate compactor. Bedding material beneath the haunch should be hand tamped by stabbing the bedding with a shovel to provide adequate pipe support. 4.5.4 General Trench Backfill The general trench backfill placed above the pipe zone should consist of material free of organic debris and other deleterious material. The general trench backfill material should be placed in loose lifts not greater than eight inches thick and compacted to at least 95% of the maximum modified Proctor dry density (ASTM D 1557) for the upper three feet below pavement areas. The remainder of the trench backfill should be compacted to 90% of the maximum modified Proctor dry density (ASTM D 1557). Heavy compaction equipment should not be used until at least two feet of material has been placed above the crown of the pipe. Backfill materials within two feet of the crown ' should be compacted with light, hand -operated compaction equipment. Alternatively controlled -density fill (CDF) could be used in place of granular backfill. 1 Golder Associates January 12, 2000 10 993-1606.300 4.6 Post -Construction Settlements and Construction Observation For the proposed pipeline alignment and invert elevations, we estimate that the total post -construction settlements after the pipe placement will be negligible provided that construction is adequately monitored and the subgrade and backfill placement recommendations in this report are followed. Therefore, we recommend full time monitoring of the-backfill placement operations -in order to -verify proper subgrade- - preparation and compaction of backfill. Golder Associates January 12, 2000 11 993-1606.300 ' 5. CONSTRUCTION CONSIDERATIONS ' 5.1 Temporary Construction Surfaces Over much of the alignment and particularly between stations 7+00 to 11+00, the ground surface is soft and wet, and will not support construction equipment. Therefore, we recommend that a temporary working surface be provided to allow for construction access. Within the wetland areas, this surface should be removed to allow for restoration. Temporary working surfaces consisting of wood chips or wood spalls (bark that is removed from logs prior to milling) can be used to provide the temporary working surface. Between stations 7+00 to 11+00, a reinforcing geogrid or geotextile may be required between the temporary working surface and the existing ground ' surface. The reinforcement should be laid in two strips, one on each side of the proposed trench excavation. Alternatively, steel sheets laid on the ground in the wetland areas could also provide a working surface for the construction equipment. ' Based on recent experience with PSE (Puget Sound Energy), the use of steel sheets as a working surface over soft ground were found to be more effective than other methods. 5.2 Dewatering The contractor should be responsible for dewatering of groundwater to control heave and maintain a dry excavation. The dewatering system should be sufficient to remove groundwater below the bottom of the trench, so that the subgrade is not disturbed and so that it remains firm under the feet of the workmen. We expect that active dewatering may be necessary over the majority of the alignment. An active dewatering system, such as a series of wells or well points appear feasible to dewater the site. We ' recommend that the groundwater table be lowered to at least 3 feet below the bottom of the trench. Detailed dewatering design criteria was beyond the scope of this report; however, typical hydraulic conductivities of recessional sands in the Puget Sound Region range from 1 x 10' cm/s to 1 x 10' cm/s. Based on the grain size analyses performed on the recessional sands (the results are contained in Appendix B), we recommend that a hydraulic conductivity on the order of 1 x 10' cm/s be used for preliminary design of the dewatering system and estimation of pumping rates. We recommend that the contract documents be structured such that design of the dewatering system is the Contractors responsibility. If the water pumped from the dewatering system is discharged into a natural drainage course, a permit will likely be required by the WSDOE. Alternatively, the water could be discharged into the storm or sewer system. 5.3 Erosion Control Prior to and during construction, we recommend that an erosion and sediment control system be installed and maintained to prevent transport of sediment into the wetlands and drainage ditches. To minimize sediment and site disturbance, we recommend that the construction be performed during the dry season. We recommend that the erosion Golder Associates IJanuary 12, 2000 12 993-1606.300 ' and sediment control system be designed in accordance with Appendix D — Erosion and Sediment Control Standards, King County, Washington, Surface Water Design Manual, ' or other appropriate reference. 5.4 Restoration ' Construction of the pipeline and manhole will involve removal of vegetation and placement of temporary/permanent fills. Within the wetland areas and wetland buffers, we anticipate that temporary construction surfaces will be required to allow for support of construction traffic. Within the wetland areas, we anticipate that removal of the temporary construction surface will be required and that the disturbed areas are replanted. We recommend that the King County Surface Water Design Manual be consulted to determine the seed mix and plants that are appropriate for replanting the wetlands that have been disturbed. Specifically, Table 6.3.1.13 (page 6-45) list plants tolerant of frequent saturated soil conditions or standing water. If possible, within the wetland areas, we recommend that the ground surface be restored to the preconstruction grades. This is to insure that the surface water and groundwater flow ' regime will be the same as the preconstruction conditions. I Golder Associates January 12, 2000 13 993-1606.300 ' 6. USE OF THIS REPORT ' This report has been prepared exclusively for the use of The City of Renton and their consultants for specific application to this project. This report pertains only to the project design plans that were provided to Golder, showing the proposed location of the pipeline alignment and manhole locations. We recommend that Golder be allowed to review the final project documents to evaluate conformance and implementation of our geotechnical recommendations. Additional explorations and site evaluation may be needed if significant design changes are made. Our exploration was performed in general accordance with locally accepted geotechnical engineering practice to provide information for the area explored. There are possible variations in the subsurface conditions between the exploration areas and in the groundwater conditions with time. We recommend that a contingency for unanticipated conditions be included in the construction schedule and budget. 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I 42 BH=2 _ I i= x I II e e< d ��' 4N f-- � as .0 3N 3r','y c31q0^ Lt't[Sfeft 3 ,MTHet 3•BL,ST.00 M c-7- BH;6_'- 8 _ LEGEND 13H-3 Q� Borehole location and designation wmu--z 0 120 FEET FIGURE 2 SITE AND EXPLORATION PLAN CITY OF RENTONMIGHGATE SEWERMA PROJECT NO. 993 1606.300 DRAWING NO. 91054 DATE 12/22/99 DRAWN BY EA Golder Associates Appendix A r m w m= m r w = = m w= m m m m= I 1 1 11 APPENDIX A BOREHOLE LOGS Golder Associates LI JI 11 11 71 Unified Soil Classification System Soil Clossification Criteria for Assigning Group Symbols and Names Generalized Group 'Descriptions COARSE —GRAINED SOILS GRAVELS CLEAN GRAVELS GW well —graded Gravels More than 50% retained on No. 200 sieve More than 50% of coarse fraction retained on No. 4 Sieve Less than 5% fines GP Poorly—groded grovels GRAVELS WITH FINES More than 12% fines GM rove) and Silt Mixtures GC ravel and Clay Mixtures SANDS CLEAN SANDS SW Well —graded Sands 50% or more of Less than 5% fines SP Poorly —graded Sands coarse fraction posses No. 4 Sieve SANDS WITH FINES SM Sand and Silt Mixtures More than 12% fines SC Sand and Clay Mixtures FINE—GRAINED SOILS 50% or more posses the No. 2DO sieve SILTS AND CLAYS Liquid limit less than 50 INORGANIC CL Low —plasticity Cloys ML Non —plastic and Low— Plasticity Silts Non —plastic and Low — ORGANIC OL Plasticity Organic Clays Non —plastic and Low — Plasticity Organic Silts SILTS AND CLAYS Liquid limit INORGANIC CH High —plasticity Clays MH High —plasticity Silts greater than 50 High—plosbcdy ORGANIC OH Organic Clays High —plasticity Organic Silts HIGHLY ORGANIC SOILS Primarily organic matter, dark in color, and organic odor PT Peat Relative Density or Consistency Utilizing Standard Penetration Test Values Cohesionless Soils (a) Cohesive Soils (b) (c) (c) Relative (c) Undrained (d) Density N, blows/ft. Density Consistency N, blows/ft. Shear 7. pStrength sf 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 Compact 10 to 30 35 — 65 Firm 4 to 6 500-1000 Dense 30 to 50 65 — 85 Stiff 8 to 15 1000-2000 Very Dense over 50 >85 Very Stiff 15 to 30 2000-4000 Hard over 30 >4000 ' (a) Soils consisting of gravel, sand, and silt, either separately or in combination, possessing no characteristics of plasticity, and exhibiting drained behavior. (b) Soils possessing the characteristics of plasticity, and exhibiting undrained behavior. (c) Refer to text of ASTM D 1586-84 for a definition of N; in normally consolidated cohesionless soils Relative Density terms ore based on N values corrected for overburden pressures. ' (d) Undrained shear strength - 1/2 unconfined compression strength. Descriptive Terminology Denoting Component Proportions Descriptive Terms Range of Proportion Trace 0-5R Little (a) 5-12% Some or Adjective 12-30% And 30-50% (a) Use Gravelly, Sandy or Silty as appropriate. Component Definitions by Gradation Component Size Range Boulders Above 12 in. Cobbles 3 in. to 12 in. Gravel 3 in. to No. 4 (4.76mm) Coarse gravel 3 in. to 3/4 in. Fine grove: 3/4 in, to No. 4 (4.76mm) Sand No. 4 (4.76mm) to No. 200 (0.074mm) Coarse sand No. 4 (4.76mm) to No. 10 (2.Omm) Medium sand No. 10 (2.Omm) to No. 40 (0.42mm) Fine sand No. 40 (0.42mm) to No. 200 (0.074mm) Silt and Clay I Smaller than No. 200 (0.074mm) Figure SOIL CLASSIFICATION/LEGEND Samples SS SPT Sampler (2.Y* OD) HD Heavy Duty Split Spoon SH Shelby Tube P Pitcher Sampler B Bulk C Cored Unless otherwise noted, drive samples advanced with 140 lb. hammer witn 30 in. drop. Laboratory Tests Test Designation Moisture (1) Density 0 Grain Size G Hydrometer H Atterberg Limits (1) Consolidation C Unconfined U UU Triax UU CU Triax CU CO Triox CD Permeability P (1) Moisture and Atterberg Limits plotted on log. Silt and Clay Descriptions Description Typical Unified Designation Silt ML (non—plostic) Clayey Silt CL—ML (low plasticity) Silty Clay CL Clay CH Plastic Silt MH Organic Soils OL, OH, Pt 2. Golder Associates 773-1D64/FORM 573 1� 1 1 1 I PROJECT: Renton/Highgate RECORD OF BOREHOLE BH-1 SHEET 1 OF 1 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 O x SOIL PROFILE SAMPLES PENETRATION RESISTANCE BLOWS/Fr. 0 PIEZOMETER Lu Lu 0 0 0 0 0 GRAPHIC w v ELEV ¢ BLOWS/6IN. z z DESCRIPTION cn x a < w m w N a WATER CONTENT,PERCENT WATER a w Cr 0 U U) Q O 0 C7 DEPTH i o_ 140 lb. hammer U w W WI p` LEVEL o m 7) z 30 inch drop ¢ 256.0 0 Forest duff Compact, light brown, nonstratified, fine to coarse SAND, trace angular gravel, some silt, damp (RECESSIONAL OUTWASH) 2.5 SM 1 SS 9-9-9 18 18/18 04.4 G 4.0 5 Compact, olive brown, nonstratified, silty, fine to SM 2 SS 5-6-7 13 18/18 0 ATD coarse SAND, trace gravel, iron stained, interbedded clayey silt lenses, moist to wet 9.0 U) (RECESSIONAL OUTWASH) 10 x 18.4 12.5 SM.' 3 SS 6-7-11 18 18/18 0 14.0 15 17.5 SM '. 4 SS 35-40-50/6 >50 lam 8.70 Boring Terminated @ 19.0 it bgs 19.0 20 25 30 DRILL RIG: B-24 LOGGED: SLY! 0,older DRILLING CONTRACTOR: Boretec CHECKED: DPF 042, DRILLER: Rich DATE: 12/14/99 A&sociaws I L 11 PROJECT Renton/Highgate RECORD OF BOREHOLE BH-2 SHEET 1 OF 1 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 O x SOIL PROFILE SAMPLES PENETRATION RESISTANCE OWS/■ BO0 PIEZOMETER 0 io ED GRAPHIC LL U ELEV. ¢ BLOWS / 6 IN. H z DESCRIPTION m a m w N a WATER CONTENT,PERCENT WATER a- O ¢ O DEPTH 2 o_ 140 lb. hammer u w W ; WI p LEVEL o m t7 z 30 inch drop cl 248.0 0 Forest duff Loose, dark brown, nonstratified, silty SAND, SM trace gravel, organics present as roots and wood, moist (FILL) Loose, olive brown, laminated, silty fine SAND, SM 2.5 iron stained. wet (RECESSIONAL OUTWASH) 1 SS 3-3-4 7 18/18 ■ 29.30 ATD 4.0 5 0 — — — — — — — 15.0 7.5 Dense, olive gray, nonstratified, silty fine to coarse SM 2 SS 20-26-15 41 18/18 0 SAND, little subrounded gravels, occasional iron staining, moist to wet (TILL) 9.0 10 13.5 12.5 SM 3 SS 20-23-18 41 18/18 0 Boring Terminated @ 14.0 it bgs 14.0 15 20 25 30 DRILL RIG: B-24 LOGGED: SLM DRILLING CONTRACTOR: Boretec CHECKED: DPF OMNI,,Associaws DRILLER: Rich DATE: 12/17/99 L� I 1 1 L PROJECT: Renton/Highgate RECORD OF BOREHOLE BH-3 SHEET 1 OF 1 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 O = SOIL PROFILE SAMPLES PENETRATION RESISTANCE BLOWS/FT PIEZOMETER w w 0 0 0 0 0 GRAPHIC LL U ELEV. BLOWS / 6 IN. M z DESCRIPTION a m N < WATER CONTENT,PERCENT WATER w O a °C a 140lb. hammer 0 p WI LEVEL p co D z 30 inch drop 251.0 0 Forest duff Loose, dark brown, nonstratified, silty SAND, organics present as roots and wood, moist to wet (FILL) 2.5 Compact, reddish olive brown, nonstratified, fine SM ATD to coarse SAND, little silt, wet (RECESSIONAL 1 SS 1-4-4 8 2'/18 18.8 0 OUTWASH) 4.0 5 2 a coarsening with depth 7.5 SW 2 SS 8-9-11 18 18/18 20.4 G 9.0 10 12.5 SM 3 sS 15-16-22 38 18/18 012.5 Boring Terminated @ 14.0 it bgs 14.0 15 20 25 30 DRILL RIG: B-24 LOGGED: SLM DRILLING CONTRACTOR: Boretec CHECKED: DPFWld� DRILLER: Rich DATE: 12/17/99 Amodaws L u fl I I PROJECT: Renton/Highgate RECORD OF BOREHOLE BH-4 SHEET OF 1 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 0 O x SOIL PROFILE SAMPLES PENETRATION RESISTANCE BOOWS/0 ■ PIEZOMETER 0 0 0 GRAPHIC W i U ELEV. a: BLOWS / 6IN. H Z DESCRIPTION cn a O m w N ? WATER CONTENT,PERCENT WATER a- cc 7) ¢ DEPTH 2 Z a 140 lb. hammer U �/ Wp WI LEVEL 00 m0 O 30 inch drop cl 250.0 Forest duff 0 Soft, dark brown, nonstratified, organic, fibrous PT PEAT, wood fragments, moist to wet (PEAT) ATD 2.5 Loose, olive brown, nonstratified, fine to coarse SW - 1 SS 4-3-3 6 18/18 ■ 023.9 132.2 SAND, trace silt, little organics, wet (RECESSIONAL OUTWASH) 4.0 5 U) x 'v 2 SS 5-8-11 19 18/18 F7.19.5SW 10 Very dense, olive brown, nonstratiffed, silty SAND, little gravel, moist (TILL) 12.5 SM 3 SS 50/4' .50 4/18 011.4 Boring Terminated @ 14.0 ft bgs 14.0 15 20 25 30 DRILL RIG: B-24 LOGGED: SLM DRILLING CONTRACTOR: Boretec CHECKED: DPFGoldex DRILLER: Rich DATE: 12/17/99 A.S. it I I fl I 1 PROJECT Renton/Highgate RECORD OF BOREHOLE BH-5 SHEET 1 OF 1 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 O = SOIL PROFILE SAMPLES PENETRATION RESISTANCE BLOWS/FT. 0 PIEZOMETER w W 0 0 0 0 0 GRAPHIC LL v ELEV Ir BLOWS/61N. H Z DESCRIPTION m a m W N a WATER CONTENT,PERCENT WATER a wQ ¢ Om 0 Q DEPTH a 140lb.hammer U W �J p� WI LEVEL D z 30 inch drop ¢ 250.0 Soft, dark brown, nonstratlfied, organic, fibrous 0 PEAT, little sand and wood fragments, moist to wet (PEAT) ATD 2.5 PT 1 SS 1-4-5 9 18/18 0 49.5 Loose, olive brown, nonstratified, organic SW -- 4.0 CLAYEY SILT, little sand, organics present as roots and wood, wet (PEAT/ORGANIC SILT) 7 5 < Compact, light brownish gray, nonstratified, silty = fine to coarse SAND, wet (RECESSIONAL OUTWASH) 7.5 SM 2 SS 8-12-14 26 18/18 16.60 9.0 10 12.5 SM 3 SS 8-12-17 29 18/18 020.9 G Boring Terminated @ 14.0 It bgs 14.0 15 20 25 30 DRILL RIG: B-24 LOGGED: SLIM DRILLING CONTRACTOR: Boretec CHECKED: DPFGolder DRILLER: Rich DATE: 12/17/99 C 1 I PROJECT Renton/Highgate RECORD OF BOREHOLE BH-6 SHEET 1 OF 1 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 O = SOIL PROFILE SAMPLES PENETRATION RESISTANCE BLOWS/FT PIEZOMETER 0 0 0 0 0 GRAPHIC LL � U = ELEV. 2 BLOWS / 6 IN. Z DESCRIPTION rn a m w N < WATER CONTENT,PERCENT WATER w O � ¢ p DEPTH Z a 140 lb. hammer w X Wp. WI LEVEL o Co 0 30 inch drop Q 257.0 Loose, olive gray, nonstratified, mottled, fine to 0 medium SAND, little silt, trace gravel, iron staining, moist to wet (FILL) 2.5 SM �. 1 SS 4-3-3 6 18/18 0 19.3 4.0 ATD 5 S 0 _ _ _ _ _ _ -'`- 19.8 25.2 7.5 Compact, olive gray, nonstratified, fine to medium SM 2 SS 1-5-8 13 18/18 0 o SAND, some silt, wet (RECESSIONAL gp OUTWASH) 10 interbeds of laminated gray silt 12.5 SM 3 SS 8-6-4 10 18/18 11 o 21.4 G Boring Terminated @ 14.0 ft bgs 14.0 15 20 25 30 DRILL RIG: B-24 LOGGED: SLM DRILLING CONTRACTOR: Boretec CHECKED: DPF 042FROGolder DRILLER: Rich DATE: 12/17/99 A&SociaWs Appendix Q m w m m m m m m m m m ■r m m m r r m r I i] 11 d APPENDIX B LABORATORY TEST RESULTS Golder Associates L C 1 GOLDER ASSOCIATES, INC. -- REDMOND, WA MOISTURE CONTENT CALCULATION SHEET ASTM D-2216 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA PROJ. NO: 993-1606.200 DATE: 10/28/99 TECH: TCM REVIEW: TCM BORING SAMPLE DEPTH (ft) WET WT. (9) DRY WT. (9) TARE WT. TARE (9) NO. MOISTURE N BH-1 S-1 2.5 395.40 382.40 85.20 4.4 BH-1 S-2 7.5 451.70 401.00 90.20 16.3 BH-1 S-3 12.5 453.70 395.20 77.80 18.4 BH-1 S-4 17.5 457.20 427.70 88.30 8.7 BH-2 S-1 2.5 369.80 306.40 89.70 29.3 BH-2 S-2 7.5 565.00 503.00 89.90 15.0 BH-2 S-3 12.5 470.30 423.20 73.40 13.5 BH-3 S-2 7.5 593.90 506.60 78.90 20.4 BH-3 S-3 12.5 515.10 467.70 89.40 12.5 BH-4 S-1 up 2.5 190.20 137.60 97.80 132.2 BH-4 S-1low 2.5 384.20 327.60 90.90 23.9 BH-4 S-2 7.5 516.30 446.70 90.50 19.5 BH-4 S-3 12.5 238.90 225.50 108.30 11.4 BH-5 S-1 2.5 329.30 249.10 87.10 49.5 BH-5 S-2 7.5 583.90 516.00 107.00 16.6 BH-5 S-3 12.5 523.90 449.10 90.70 20.9 BH-6 S-1 2.5 466.80 406.00 91.20 19.3 BH-6 S-2 up 7.5 381.00 332.90 89.90 19.8 BH-6 S-2low 7.5 480.50 405.30 107.00 25.2 BH-6 S-3 12.5 468.80 405.10 107.00 21.4 BH-3 S-1 2.5 181.40 169.70 107.60 18.8 ' GOLDER ASSOCIATES, INC. -- REDMOND, WA GRAIN SIZE ANALYSIS -- WASH SIEVE ASTM D1140 / D422 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA PROJECT NO: 993-1606.200 DATE: 11 /1 /99 TECH: TCM REVIEWER: TCM BOREHOLE BH-1 SAMPLE S-1 DEPTH (ft) 2.5-4 ' Description: Brownish Gray, F-M SAND, some silt, trace fine gravel USCS: SM ' NATURAL MOISTURE C Gravel 0.0% ' Tare Number F Gravel 1.8% Wet Weight + Tare (g) 583.00 C Sand 8.1 % Dry Weight + Tare (g) 570.00 M Sand 44.4% Tare Weight (g) 272.80 F Sand Water Content (%) 4.4 / Fines 13.1 Sieve Retained Passing ' (g) cum. tare 272.80 3" 272.80 100.0% LL 2" 272.80 100.0% PL 1 " 272.80 100.0% PI 3/4" 272.80 100.0% 3/8" 274.70 99.4% #4 278.20 98.2% ' #10 302.40 90.0% #20 363.30 69.5% D10: 0.060 #40 434.40 45.6% D30: 0.15 #60 483.20 29.2% D60: 0.6 #100 508.20 20.8% Cu: N/A #200 531.10 13.1 % Cz: N/A 0 (M c U) CU a 01 0 PARTICLE SIZE DISTRIBUTION US STANDARD SIEVE OPENING SIZES _. _. �/e. u., Ain AM *40 #60 #100 #200 Coarse I Fine GRAVEL Grain Size (mm) Coarse I Medium I Fine SAND FINES (Silt or Clay) DEPTH (ft) 2 5-4 W% 4.4% LL PL PI I USCS SM DESCRIPTION Brownish Gray, F-M SAND, some silt, trace fine gravel SAMPLE ID BH-1 S-1 0 PROJECT: CITY OF RENTON./ HIGHGATE SEWER / WA GOLDER ASSOCIATES, INC. PROJECT NO.: 993-1606.200 DATE: 11/1/99 TECH: TCM REVIEW: TCM REDMOND, WA GOLDER ASSOCIATES, INC. -- REDMOND, WA GRAIN SIZE ANALYSIS -- WASH SIEVE ASTM D1140 / D422 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA ' PROJECT NO: 993-1606.200 DATE: 11 /1 /99 TECH: TCM REVIEWER: TCM BOREHOLE BH-3 SAMPLE S-2 DEPTH (ft) 7.5-9 Description: Light Yellowish Brown, F-M SAND, little silt, trace f gravel USCS: SW NATURAL MOISTURE C Gravel 0.0% '. Tare Number F Gravel 1.5% Wet Weight + Tare (g) 825.40 C Sand 4.8% Dry Weight + Tare (g) 738.10 M Sand 35.1 % ' Tare Weight (g) 310.40 F Sand 48.7% Water Content (%) 20.4%1 Fines 9.9% Sieve Retained Passing (g) cum. tare 310.40 3" 310.40 100.0% LL 2" 310.40 100.0% PL 1 " 310.40 100.0% PI 3/4" 310.40 100.0% 3/8" 310.40 100.0% #4 316.80 98.5% #10 337.20 93.7% #20 394.20 80.4% D10: 0.075 #40 487.40 58.6% D30: 0.25 #60 608.80 30.2% D60: 0.4 #100 668.60 16.2% Cu: 5.9 #200 695.90 9.9% Cz: 1.9 0 CM c ca a OR O !`n PARTICLE SIZE DISTRIBUTION US STANDARD SIEVE OPENING SIZES .,- .,- ;- CIA- via- Ltd #in #20 #40 #60 #100 #200 Grain Size (mm) Coarse Fine Coarse Medium Fine FINES (Silt or Clay) GRAVEL SAND SAMPLE ID DEPTH ft W% LL PL PI USCS DESCRIPTION BH-3 7.5-9 20.4% SW Light Yellowish Brown, F-M SAND, S-2 little silt, trace f gravel 0 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA GOLDER ASSOCIATES, INC. PROJECT NO.: 993-1606.200 DATE: 11/1/99 TECH: TCM REVIEW: TCM REDMOND, WA GOLDER ASSOCIATES, INC. -- REDMOND, WA GRAIN SIZE ANALYSIS -- WASH SIEVE ASTM D1140 / D422 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA ' PROJECT NO: 993-1606.200 DATE: 11 /1 /99 TECH: TCM REVIEWER: TCM ' BOREHOLE BH-5 SAMPLE S-3 DEPTH (ft) 12.5-14 Description: Light Brownish Gray, silty fine to medium sand ' USCS: SM NATURAL MOISTURE C Gravel 0.0% ' Tare Number F Gravel 0.0% Wet Weight + Tare (g) 748.00 C Sand 0.6% Dry Weight + Tare (g) 673.20 M Sand 11.90 Tare Weight (g) 314.80 F Sand 39.20/c Water Content (%) 20.9% Fines 48.40/c 1 L Sieve Retained Passing (g) cum. tare 314.80 3" 314.80 100.0% LL 2" 314.80 100.0% PL 1" 314.80 100.0% PI 3/4" 314.80 100.0% 3/8" 314.80 100.0% #4 314.80 100.0% #10 316.80 99.4% #20 324.70 97.2% D10: 0.004 #40 359.30 87.6% D30: 0.02 #60 430.60 67.7% D60: _ 0.2 #100 468.30 57.2% Cu: N/A #200 499.70 48.40/6 Cz: N/A 1 C N ca a 01 0 PARTICLE SIZE DISTRIBUTION US STANDARD SIEVE OPENING SIZES u,n aon .4an *An *100 #200 Grain Size (mm) Coarse Fine Coarse Medium Fine GRAVEL SAND FINES (Silt or Clay) DEPTH ft W% LL PL PI USCS DESCRIPTION SAMPLE ID BH-5 S-3 12.5-14 20.9% SM Light Brownish Gray, silty fine to medium sand 0 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA GOLDER ASSOCIATES, INC. PROJECT NO.: 993-1606.200 DATE: 11/1/99 TECH: TCM REVIEW: TCM REDMOND, WA GOLDER ASSOCIATES, INC. -- REDMOND, WA GRAIN SIZE ANALYSIS -- WASH SIEVE ASTM D1140 / D422 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA PROJECT NO: 993-1606.200 DATE: 11 /1 /99 TECH: TCM REVIEWER: TCM BOREHOLE BH-6 SAMPLE S-3 DEPTH (ft) 12.5-14 Description: Gray, F SAND, some silt USCS: SM NATURAL MOISTURE Tare Number Wet Weight + Tare (g) Dry Weight + Tare (g) Tare Weight (g) Water Content (%) 674.40 610.70 312.60 21.4% C Gravel F Gravel C Sand M Sand F Sand Fines 0.0% 0.0% 0.2% 2.1 % 77.0% Sieve Retained Passing tare 3" 2" 1" 3/4" 3/8" #4 #10 #20 #40 #60 #100 #200 (g) cum. 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 99.8% 99.5% 97.7% 91.1 % 64.1 % 20.8% LL PL PI D10: D30: D60: Cu: Cz: 0.060 0.09 0.2 N/A N/A 312.60 312.60 312.60 312.60 312.60 312.60 312.60 313.10 314.00 319.40 339.00 419.50 548.80 1 C cn U) CC a OR 0 01A- IMP AA PARTICLE SIZE DISTRIBUTION US STANDARD SIEVE OPENING SIZES -tin #20 #40 #60 #100 #200 Grain Size (mm) Coarse Fine Coarse Medium Fine GRAVEL SAND FINES (Silt or Clay) SAMPLE ID DEPTH ft W% LL PL PI USCS DESCRIPTION BH-6 12.5-14 21.4% SM Gray, F SAND, some silt S-3 0 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA GOLDER ASSOCIATES, INC. PROJECT NO.: 993-1606.200 DATE: 11/1/99 TECH: TCM REVIEW: TCM REDMOND, WA Golder Associates Inc. 18300 NE Union Hill Road, Suite 200 Redmond, WA 98052-3333 Telephone (425) 883-0777 Fax (425) 882-5498 9 lsoc �tes = Go SUBSURFACE INVESTIGATION AND GEOTECHNICAL ENGINEERING REPORT FOR THE HIGATE SEWER PROJECT RENTON, WASHINGTON }c - Shawn L. McNamara Staff Geological Engineer January 12, 2000 Prepared for: City of Renton Planning/Building/Public Works Department 1055 South Grady Way Renton, Washington 98055 Submitted by: Golder Associates Inc. 18300 NE Union Hill Road, Suite 200 Redmond, Washington 98052 ARD D. WAS, 4,9 EXPMS / C Richard D. Luark, P.E. Associate Engineer L 993-1606.300 0112rdll.do OFFICES IN AUSTRALIA, CANADA, GERMANY, HUNGARY, ITALY, SWEDEN, UNITED KINGDOM, UNITED STATES January 12, 2000 i 993-1606.300 ITABLE OF CONTENTS Page No. 1. INTRODUCTION 1 1.1 Purpose and Scope of Services 1 1.2 Project and Site Description 1 2. GEOTECHNICAL INVESTIGATIONS 3 2.1 Field Investigations 3 2.2 Laboratory Testing 3 3. SUBSURFACE CONDITIONS 4 3.1 General 4 3.2 Geologic Setting 4 3.3 Soil 4 3.4 Groundwater 6 4. ENGINEERING RECOMMENDATIONS 7 4.1 General 7 4.2 Trenched Excavations 7 4.3 Trenchless Excavations 7 4.4 Liquefaction 8 4.5 Trench Backfill Materials 9 4.5.1 Reuse of Construction Spoils 9 4.5.2 Subgrade Preparation 9 4.5.3 Pipe Bedding 9 4.5.4 General Trench Backfill 9 4.6 Post -Construction Settlements and Construction Observation 10 5. CONSTRUCTION CONSIDERATIONS 11 5.1 Temporary Construction Surfaces 11 5.2 Dewatering 11 5.3 Erosion Control 11 5.4 Restoration 12 6. USE OF THIS REPORT 13 LIST OF FIGURES Figure 1 Site Location Map Figure 2 Site and Exploration Plan LIST OF APPENDICES Appendix A Boring Logs Appendix B Laboratory Testing Golder Associates ' January 12, 2000 1 993-1606.300 1. INTRODUCTION 1.1 Purpose and Scope of Services The City of Renton retained Golder Associates Inc. (Golder) to provide geotechnical ' consulting services for the proposed sewer line, located in North Renton, east of 405 near the Kennydale Hill area (Figure 1). The purpose of the activities described in this report was to characterize the subsurface geologic conditions, provide general geotechnical conclusions and recommendations and guidelines related to the construction of the sewer line including trenches technology recommendations, and criteria for restoration of the disturbed areas. Golder's geotechnical work activities consisted of subsurface and engineering analyses, performed in accordance with our proposal dated August 5,1999. This report presents the results of the field investigations and provides geotechnical design criteria for the project. 1.2 Project and Site Description ' We understand that the City of Renton is planning a new 8-inch-diameter sanitary sewer line in a residential area of North Renton. The new line would allow elimination of an existing pump station and force main. The sewer line would run from an existing MH at Jones Ave NE, due east across a vegetated utility easement and drainage ditch, then due south to NE 20'H Street, and west up 20`" street about 23 feet to an existing MH. The total length of each segment is summarized below. Segment Length (ft.) East-West from Jones Ave. 409 South to NE 20`h St. 612 NE 20"' St. 23 TOTAL LENGTH 1,044 The proposed sewer project is located in North Renton, east of 405 near the Kennydale ' Hill area. The sewer line is divided into three segments as indicated above. East-West From Jones Avenue This section of the sewer alignment runs from station 1 +00 to 5+00. From station 1 +00 to 2+00 the line travels east underneath Jones Ave NE into an undeveloped lot with minimal grass and weed cover before hitting a series of trees near 2+00. Just beyond the trees at the back of the undeveloped lot the line crosses under a drainage ditch near ' station 3+00. From station 3+00 to 5+00 the line travels through a sparsely wooded area covered with blackberry bushes. At station 5+00 the line makes a 90-degree turn ' south. Golder Associates January 12, 2000 2 993-1606.300 I There is little to no topographic relief between station 1+00 and 3+00 except for the sharp drop into the drainage ditch. From station 3+00 to 5+00 there is approximately 10 feet change in elevation as the site slopes up to the east. The soil cover above the sewer line between station 1+00 and 5+00 varies from approximately 3 to 14 feet respectively. South to NE 20s' Street This section of the alignment runs from station 5+00 toll +00. From station 5+00 to 6+00 the line travels south under a thick cover of blackberry bushes. Within the blackberry bushes there are remains of 2 old cars and a camper from the residence nearby. From station 6+00 to 7+00 the line continues south beneath the cover of thick blackberry bushes and beneath the remains of an old decaying barn. From station 7+00 to 8+00 the line passes beneath an increasing thickness of blackberry bushes and alongside the residence at 3201 NE 20' Street. It is also at this point that the soils directly at the surface become increasingly soft and the depth to groundwater is significantly decreasing (wetlands). From station 8+00 to 10+00 the line passes beneath several blackberry bushes rooted within the wetlands. The groundwater table in this area is extremely high and the soil is almost too soft for foot travel. From 10+00 to 11+00 the line passes along side the residence located at 3202 NE 20' Street and into a manhole in the middle of NE 20' Street. The blackberry bushes are not present in this area. There is a row of poplars running parallel to the line up to NE 20' Street. The site slopes gently downward to the south along the line between stations 5+00 and 11+00 with a topographic relief of approximately 5 feet. The soil cover above the proposed sewer line, between station 5+00 and 11+00, varies from approximately 14 to 4 feet respectively. NE 20' Street From the manhole in the middle of NE 20' Street the line continues 23 feet to the west underneath NE 20' Street to an existing manhole. NE 20' Street rises steadily to the east toward the existing manhole with a topographic relief of approximately 0.28 feet. The soil cover above the 23-foot run down NE 20' Street is approximately 5.5 feet. Golder Associates January 12, 2000 3 993-1606.300 1 I I Ll 2. GEOTECHNICAL INVESTIGATIONS 2.1 Field Investigations Field investigations including six test borings (1314-1, BH-2, BH-3, BH-4, BH-5, and BH-6) were conducted on October 4,1999. The exploration locations are shown on Figure 2. Golder's test borings were drilled with a convertible trailer mounted/skid mounted, B-24 drill rig. In order to complete borings within the wetland area the rig was taken off the trailer and pulled to the drilling locations by a dozer. Boretech provided the drill rig and crew, while the dozer was provided by Northwest Excavating, both under subcontract to Golder Associates. Drilling and sampling of soils were performed in accordance with Golder Technical Procedure TP-1.2-5, "Drilling, Sampling, and Logging of Soils". Standard Penetration Tests (SPT) were performed at 5-foot intervals using a standard two-inch diameter split spoon sampler driven by a 140-pound hammer falling a distance of 30 inches, in accordance with ASTM D-1586. A Golder field geologist examined and logged the soil from the borings and recorded the groundwater conditions. The soil samples were classified in accordance with Golder Technical Procedure TP-1.2-6, "Field Identification of Soil", which is summarized on the Soil Description Index in Appendix A. All samples were placed in plastic jars and returned to our Redmond, Washington, laboratory for further classification and testing. At the completion of drilling, all of the borings were backfilled with bentonite chips and cuttings to just below the ground surface. 2.2 Laboratory Testing Geotechnical laboratory index testing was performed on selected samples from the borings. Testing consisted of grain size and moisture. Detailed test results are presented in Appendix B and on the boring logs. Golder Associates 1 January 12, 2000 4 993-1606.300 3. SUBSURFACE CONDITIONS 3.1 General The summary boring logs are presented in Appendix A. Pertinent information including depths, stratigraphy, soil engineering characteristics, and groundwater occurrence were recorded and summarized. The stratigraphic contacts indicated on the summary logs represent the approximate boundaries between soil types. It should be noted that soil conditions are accurate only at the location of drilling and may vary between boreholes. 3.2 Geologic Setting The project is located in the vicinity of the eastern shore of Lake Washington in the Puget Sound region of Washington State. The recent geologic history of Puget Sound ' was dominated by the influence of glaciers. Nearly the entire Puget lowland is covered by deposits from the Pleistocene Glaciers, the most recent of which receded approximately 13,500 years ago. The most recent glaciation, named the Vashon, deposited soil units consisting of lacustrine silts and clays, advance outwash sand, till and recessional outwash. These deposits, and the weathered soils derived from them, make up nearly all of the near -surface soils on the slopes and higher elevations around Lake Washington. The project area is dominated by two of these glacial deposits, recessional outwash sand and till, with smaller amounts of peat and man -placed fills. 3.3 Soil Based on the soil conditions encountered in the borings, the stratigraphy is quite variable across the site. In general, the site appears to be underlain by layer of loose to very dense fill or in some locations peat, overlying deposits of loose to compact fine to coarse recessional outwash and very dense glacial till. Soil units encountered in our borings are summarized below: • FILL: Approximately 2.5 feet of fill was encountered in BH-2, 3 feet in BH-3, and 8.0 feet in BH-6. The fill observed in BH-2 and BH-3 was loose silty sand with trace gravel and organics. This fill was most likely imported in the mid 1900s when the site was reported to be used as a horse pasture. The fill observed in I BH-6 was a loose to compact silty sand with trace gravel and organics with significant mottling and iron staining. Since BH-6 is located in the shoulder of Jones Avenue, this fill can most likely be attributed to a regrade or filling in of a drainage ditch when the road was put in. • PEAT: Approximately 3 feet of peat was encountered in BH4 and 3.5 feet in ' BH-5. In our borings the peat was generally soft, organic, fibrous, clayey silt, with roots and wood fragments. The peat does not seem to be continuous across the alignment. It was found only within the wetland area from station 7+00 to 11 +00. d 1 Golder Associates January 12, 2000 5 993-1606.300 Ll n i7 RECESSIONAL OUTWASH: Recessional outwash is a fluvial deposit laid down by meltwater from a stagnating or retreating glacier. In our borings the recessional outwash was generally a loose to compact, fine to coarse sand with trace to some silt. The recessional outwash was encountered in BH-1 from the surface to 16 feet. The recessional outwash was encountered in BH-2 below the upper fill from 2.5 to 8 feet. The recessional outwash was encountered in BH-3 below the upper fill from 3 feet to the end of the boring at 14 feet. The recessional outwash was encountered in BH-4 below the upper peat from 3 to 11 feet. The recessional outwash was encountered in BH-5 below the upper peat from 3.5 feet to the end of the boring at 14 feet. The recessional outwash was encountered in BH-6 below the upper fill from 8 feet to the end of the boring at 14 feet. Recessional outwash will likely be encountered at the proposed pipeline elevation intermittently from about 1+00 to 5+00, and consistently from about 5+00 to the end of the alignment at 11+00. We encountered groundwater in this unit above the proposed pipeline elevations in BH-3, BH-4, BH-5, and BH-6. TILL: Till is an unsorted, nonstratified, homogeneous mixture of gravel, sand, silt and clay deposited beneath, or adjacent to a glacier. In this region, it is typically dense to very dense due to past consolidation by the weight of thick overlying glacial ice. In our borings the till was generally a very dense, silty fine to coarse sand with little to some gravels. Although not encountered in our borings, till commonly contains cobbles and boulders. In addition, till occasionally contains discontinuous lenses of sand which commonly hold water. These lenses can initially produce moderate groundwater flow when intercepted, but the flow typically decreases rapidly with time as the water is drained from the sand lens. The glacial till was encountered in BH-1 below the recessional outwash from 16 feet to the end of the boring at 19 feet. The glacial till was encountered in BH-2 below the recessional outwash from 8 feet to the end of the boring at 14 feet. The glacial till was encountered in BH-4 below the recessional outwash from 11 feet to the end of the boring at 14 feet. Since these borings were terminated in the till, the total thickness was unknown but the till appears to be continuous along the alignment. Although the glacial till was not encountered in BH-3, BH-5, and BH-6, the contact between the recessional outwash and the till varies in depth across the site indicating that the till most likely would have been encountered if the borings had been deeper. Glacial till will likely be encountered at the proposed pipeline elevation intermittently from about station 4+00 to station 5+00. We encountered groundwater in this unit above the proposed pipeline elevations in BH-1 and BH-2. I Golder Associates January 12, 2000 6 993-1606.300 3.4 Groundwater Groundwater was encountered at the time of drilling (ATD) and in the borings as follows: • Boring BH-1 at a depth of 8 feet below the surface (ATD). • Boring BH-2 at a depth of 3 feet below the surface (ATD). • Boring BH-3 at a depth of 2.5 feet below the surface (ATD). Boring BH-4 at a depth of 1 foot below the surface. This area was very wet and soft at the surface. • Boring BH-5 at a depth of 1.5 feet below the surface(ATD). Even though this boring was located adjacent to the road (NE 20' Street), this area was very wet at the surface. • Boring BH-6 at a depth of 4.5 feet below the surface (ATD). The water table encountered was interpreted to be perched on top of the relatively impermeable glacial till that was found in our borings or inferred below the recessional sand layer. Since the water levels were measured during drilling, the actual water table may be slightly different, and could vary seasonally. In particular, the water table may be closer to the ground surface during the winter and early spring. Between station 7+00 to 11+00, the water table is likely above the existing ground surface during the winter and early spring. Golder Associates January 12, 2000 7 993-1606.300 ' 4. ENGINEERING RECOMMENDATIONS 1 4.1 General Based on our subsurface explorations, the proposed project appears feasible from a geotechnical standpoint. The bottom of the sewer trench excavation as proposed is expected to be located in either loose to compact recessional outwash sands or dense -to - very -dense glacial till. Based on the preliminary plans provided to Golder, trenchless 1 technology is proposed to advance the sewer line between stations 2+35 to 2+70, as a small drainage ditch/stream is located at about station 2+55. ' The main geotechnical issues at this site pertain to a high groundwater table combined with loose/soft soils. Temporary dewatering will be required during construction of the sewer line. Also, due to the soft ground conditions, a working surface will be required ' to support construction traffic. 4.2 Trenched Excavations Provided temporary dewatering of the saturated recessional sands is accomplished, it is P Y g P our opinion that the entire sewer line can be installed using standard trench -box excavations. Due to the soft nature of the ground surface, a working surface will be required to support construction traffic, as outlined in the construction section of this report. The excavation ahead of the trench box should be limited to the minimum ' necessary to complete the work and backfilling should follow immediately behind the box. Due to the presence of loose to compact recessional sands, combined with a high water table, sloughing, overbreak and raveling of the trench sidewalls should be ' anticipated. The contractor should be responsible for dewatering of groundwater to control sidewall Lsloughing, heave of the bottom of the trench and to maintain a dry excavation. Dewatering design criteria are contained in Section 5.2 of this report. 4.3 Trenchless Excavations In order to minimize disturbance of the small stream at station 2+50, trenchless methods may be used. Based on the size of the proposed sewer line, the most suitable methods for installation of this sewer may include horizontal bores with steel -liner jacking and microtunneling. Although trenchless methods offer distinct advantages in terms of minimizing disruption to the strean-/drainage ditch, disturbance greater than trenching should be anticipated in the vicinity of the jacking and operating pits. Steel 1 liner jacking is likely the most cost-effective method for installing the sewer beneath the stream. Due to the high groundwater table and loose nature of the recessional sands, combined with a fairly shallow invert, microtunnehng appears to be marginal at this site. Special drilling construction procedures and drilling muds would likely be required if 1 Golder Associates January 12, 2000 S 993-1606.300 microtunneling is attempted. The only advantage of trenchless installation of the sewer line is minimizing the disturbance to the wetlands present at the site. However, in the proposed alignment, manholes are spaced at approximately 400 feet, and installation would require disturbance to the wetlands for installation of the manholes. The manholes would provide logical locations for operating pits for either jacking or microtunneling. Based on our explorations completed for this study, glacial till will likely be encountered at the proposed pipeline elevation intermittently from about station 4+00 to station 5+00. Encountering till could negatively impact tunneling or jacking in two ways: 1. Boulders that may be present in the till could provide construction problems, ranging from slowed production to borehole obstruction. 2. The change in hardness at a geologic contact (loose, saturated recessional sands/very dense glacial till) may tend to deflect the auger or tunneling machine ' from its intended alignment. If trenchless excavation methods are used, bids should include contingencies for encountering boulders in the glacial till. We would expect groundwater to be encountered above the pipe invert elevation over the entire alignment. Within the saturated recessional sand, some ground loss may occur if good ' microtunneling construction practices are not followed or if liners are not jacked in advance or concurrently with the excavation face. The contractor should be responsible for control of settlement and in particular for ensuring that any settlements that occur do not affect adjacent utilities. Some form of drop shaft will need to be excavated in order to construct the manholes and to provide a staging area for microtunneling equipment. At locations where a staging area for tunneling is required, the likely minimum diameter of the drop shaft will probably be about 12 feet. The contractor should anticipate that dewatering would be required over the majority of the alignment. We expect that active dewatering measures (e.g., wellpoints) may be necessary to dewater the excavation. 4.4 Liquefaction Loose to compact granular soils below the water table can liquefy during a seismic event, causing damage to utilities buried in such soils due to lateral spreading and ground settlement. The pipe and base of the manholes will be below the permanent water table over much of the alignment. The borings indicate that loose to compact sands will be present below the proposed pipe invert, except around stations 3+00 to 1 4+00, where our boring at station 3+50 encountered glacial till slightly above the pipe invert. During the design earthquake event (7.5 magnitude), the saturated recessional sands are considered susceptible to liquefaction. The consequences of liquefaction are that the pipeline may displace or float during liquefaction. Liquefaction can be ' mitigated. However, the associated cost is typically greater than replacement for a sewer line of this size. Golder Associates IJanuary 12, 2000 9 993-1606.300 1 45 Trench Backfill Materials 45.1 Reuse of Construction Spoils In general, the outwash sands excavation spoils can be reused as trench backfill. However, materials with high silt contents (i.e., tills and the fill materials), typically can only be used for trench backfill during the drier summer month when the moisture can be controlled. The organic materials (i.e., peats), should not be used for trench backfill. 4.5.2 Subgrade Preparation In general, provided that the site is properly dewatered, we would expect that the undisturbed native site soils will provide adequate subgrade support. Loosened or disturbed material should be removed from the trench bottom prior to the placement of the pipe bedding material. Areas which contain loose or soft materials at the pipe or manhole invert should be over -excavated and replaced with crushed rock or other suitable fill material. 4.5.3 Pipe Bedding ' Pipe bedding material should be placed beneath the pipe and within the pipe zone in accordance with "Pipe Bedding for Sanitary Sewers" as adopted by the City of Renton. Bedding above and below the pipe should be hand tamped with several passes of a tvibrating plate compactor. Bedding material beneath the haunch should be hand tamped by stabbing the bedding with a shovel to provide adequate pipe support. 4.5.4 General Trench Backfill The general trench backfill placed above the pipe zone should consist of material free of organic debris and other deleterious material. The general trench backfill material should be placed in loose lifts not greater than eight inches thick and compacted to at least 95% of the maximum modified Proctor dry density (ASTM D 1557) for the upper three feet below pavement areas. The remainder of the trench backfill should be compacted to 90% of the maximum modified Proctor dry density (ASTM D 1557). Heavy compaction equipment should not be used until at least two feet of material has been placed above the crown of the pipe. Backfill materials within two feet of the crown ' should be compacted with light, hand -operated compaction equipment. Alternatively controlled -density fill (CDF) could be used in place of granular backfill. P-, 1 Golder Associates January 12, 2000 10 993-1606.300 1 4.6 Post -Construction Settlements and Construction Observation For the proposed pipeline alignment and invert elevations, we estimate that the total post -construction settlements after the pipe placement will be negligible provided that construction is adequately monitored and the subgrade and backfill placement recommendations in this report are followed. Therefore, we recommend full time monitoring of the backfill placement operations in order to verify proper subgrade preparation and compaction of backfill. 1 d 1 1 1 Golder Associates January 12, 2000 11 993-1606.300 r5. CONSTRUCTION CONSIDERATIONS ' 5.1 Temporary Construction Surfaces Over much of the alignment and particularly between stations 7+00 to 11 +00, the ground surface is soft and wet, and will not support construction equipment. Therefore, ' we recommend that a temporary working surface be provided to allow for construction access. Within the wetland areas, this surface should be removed to allow for restoration. Temporary working surfaces consisting of wood chips or wood spalls (bark that is removed from logs prior to milling) can be used to provide the temporary working surface. Between stations 7+00 to 11 +00, a reinforcing geogrid or geotextile may be required between the temporary working surface and the existing ground surface. The reinforcement should be laid in two strips, one on each side of the proposed trench excavation. Alternatively, steel sheets laid on the ground in the wetland areas could also provide a working surface for the construction equipment. ' Based on recent experience with PSE (Puget Sound Energy), the use of steel sheets as a working surface over soft ground were found to be more effective than other methods. ' 5.2 Dewaterin g The contractor should be responsible for dewatering of groundwater to control heave and maintain a dry excavation. The dewatering system should be sufficient to remove groundwater below the bottom of the trench, so that the subgrade is not disturbed and so that it remains firm under the feet of the workmen. We expect that active dewatering may be necessary over the majority of the alignment. An active dewatering system, such as a series of wells or well points appear feasible to dewater the site. We recommend that the groundwater table be lowered to at least 3 feet below the bottom of the trench. ' Detailed dewatering design criteria was beyond the scope of this report; however, typical hydraulic conductivities of recessional sands in the Puget Sound Region range from 1 x 10"2 cm/s to 1 x 10' cm/s. Based on the grain size analyses performed on the recessional sands (the results are contained in Appendix B), we recommend that a hydraulic conductivity on the order of 1 x 10'cm/s be used for preliminary design of the dewatering system and estimation of pumping rates. We recommend that the contract 1 documents be structured such that design of the dewatering system is the Contractors responsibility. If the water pumped from the dewatering system is discharged into a natural drainage course, a permit will likely be required by the WSDOE. Alternatively, the water could be discharged into the storm or sewer system. ' 5.3 Erosion Control Prior to and during construction, we recommend that an erosion and sediment control ' system be installed and maintained to prevent transport of sediment into the wetlands and drainage ditches. To minimize sediment and site disturbance, we recommend that the construction be performed during the dry season. We recommend that the erosion IGolder Associates 1 January 12, 2000 12 993-1606.300 and sediment control system be designed in accordance with Appendix D — Erosion and Sediment Control Standards, King County, Washington, Surface Water Design Manual, ' or other appropriate reference. 5.4 Restoration Construction of the pipeline and manhole will involve removal of vegetation and placement of temporary/permanent fills. Within the wetland areas and wetland buffers, we anticipate that temporary construction surfaces will be required to allow for support of construction traffic. Within the wetland areas, we anticipate that removal of the temporary construction surface will be required and that the disturbed areas are ' replanted. We recommend that the King County Surface Water Design Manual be consulted to determine the seed mix and plants that are appropriate for replanting the wetlands that have been disturbed. Specifically, Table 6.3.1.1) (page 6-45) list plants tolerant of frequent saturated soil conditions or standing water. If possible, within the wetland areas, we recommend that the ground surface be restored to the preconstruction grades. This is to insure that the surface water and groundwater flow regime will be the same as the preconstruction conditions. [l Ir-, Golder Associates January 12, 2000 13 993-1606.300 6. USE OF THIS REPORT ' This report has been prepared exclusively for the use of The City of Renton and their consultants for specific application to this project. This report pertains only to the project design plans that were provided to Golder, showing the proposed location of the pipeline alignment and manhole locations. We recommend that Golder be allowed to review the final project documents to evaluate conformance and implementation of our geotechnical recommendations. Additional explorations and site evaluation may be ' needed if significant design changes are made. Our exploration was performed in general accordance with locally accepted ' geotechnical engineering practice to provide information for the area explored. There are possible variations in the subsurface conditions between the exploration areas and in the groundwater conditions with time. We recommend that a contingency for ' unanticipated conditions be included in the construction schedule and budget. Further we recommend our firm be retained to provide consulting services during construction to confirm the conditions indicated by the explorations and/or provide corrective recommendations adapted to the conditions revealed during the work LI 11 1 Golder Associates Figures m m ! i m m m m m m m m m m m m m m m �7 1 FIGURES Golder Associates in h HIIySlO Z v 6 H < a -a 13 �L a D SE 68T wi I NEW J x r� D r o a O S ~ p w m f s- n D D 7 Z a D n 7� S 71 Nm w I 72N �' m m R w r w E 7 ! � N N Z D pj, y m to A N y�. rt' I m '^ N S „ N 8` SE 76 m mm Cn m x a Fig f x Cn m x SE 78TH?� ke Bo v m D ti r" Maur Creek � - _ z r r�i E 80T mN I m M S D �i z V Eg2N 5 ISE 3 T � • � m a y W ISF �- t � -� N� D Q 6 r Y a NTH a w I x P z r SOUth POIr11< +x =` 37T -� m � N v 36 UO k� z p© N35T 4 8 ~ O \9 34T r-- h m N r al r to W p �F c I tiF w m ya 32ND 3�ST n SIP- a 0 30z °° m rn Z w N 28T ¢ NE 28TH z i WA y< w n uj rt1 z % fie eQ� w Q) crn rr Q m r = ¢ pw > m Wm d Q O Q m ? N 24 co �^ z m E 3RDj� z n :Eo N g W p A y z Z r ➢m m �, .. E2m S `} e N LptN Q A w K z� m m N 19 y Z 18 n Z NE 17- a y w �ii y E 15T v f c m -; S ��` F L� ry5'i" •cY•` k Z D E 14TM 900 r E m E 13TH C' c, m v E12 I 0 P� D D -i E°i. z 900 D F- — D NE _ x'j Q,,y, N OTH T Duj fA !/1 o N - � O ZO NE 9TH Z z w D 117T i r z E 8 m Q 9ny z 119T a 8TH D W N m W 120TI 1 SE m _ m w D 121ST w 7TH R E E 6 H m $ Renton Muni z < N FIGURE 1 VICINITY MAP CITY OF RENTON/HIGHGATE SEWER/WA 3JECT NO. 993 1606.300 DRAWING NO. 85360 DATE 12/22/99 DRAWN BY TK Golder Associates hc39 :tl:' 4- ` Al G'Ji f ._ "a- r, - � F �S14 <�Sia`� t �y UZI j 3N 3Ay s3N01 WV ,lALt6l 3.BL$GDp M Ct'lESSOSt 3 �I 1!d.Y I]XCi N� 9� � ! pe3E35!fG4Ei5 vstnrrr---ter I r 1_ 5 t IT YD Y -1EICZ `cM, ------------------------ \. ! .___. ..... _ _CE _Sr Exams IFS �: i :iE FtRIES 1 i ._._ +I� 1 B� t— SJ '1YX(4R" Y o` PDM. S4p4T IUT Nnri_ I .vx J +SALE T TO THIN F'[S.CI'�ri xr -Fes eE,+�-,ac ri �''TG u ; < S EGT z crouTRAerGR ..� REwsE .ea: Ch9Gz Di Litt"F,^, 9ARN. Mli - •DPt GE ClC: Th_ TO <`_ 4. - _R N fCMST'fw Cry -• yVl �Stt z61 l Y BH=2f � 'rg IM l T ]iS D _a,Y. Fng due - z. E i. S ; K1P'9 G SkL 1 n1Y�P,^,A a'r_ �vElC itE t M: 3M N? •E J 1D A -\I pG CE f 11 ED TO "T BH-4! }_ rc : a_r_,xs Y�•s :�: i i .�; rr,'}i JF-------,----Pc �,.%I t.1 °X C•1:-��\' D 7 -.... _. Jt% -•0h "fit _. z 1 i ............ `.'t�'�'St•D•1.341 � i, II S E�FWARi I �.i n�DRG^FFD •t' SEAS 1 ML.T 4tS,p eY � el•n�JCT10!:J ' {,-rrrl-r)) �� �u2lC{ 'i TAX EDT ]AO 'r' 1X%)$E II No �:. �4 J �aR LEGEND -= BH-3 11� Borehole location and designation BH;6 BH 5� � r _ '1 �f �S w^, L'itp 3 ,t.'a[GOD 4 0 120 tE t y FEET 8. a FIGURE L SITE AND EXPLORATION PLAN CITY OF RENTONMIGHGATE SEWERMA I I PROJECT NO. 9931606.300 DRAWING NO. 91054 DATE 12/22/99 DRAWN BY EA Golder Associates Appendix A I 1 I APPENDIX A BOREHOLE LOGS Golder Associates Unified Soil Classification System Soil Closs;fication Criteria for Assigning Group Symbols and Names Generalized Group Descriptions COARSE —GRAINED SOILS GRAVELS CLEAN GRAVELS GW well—groded Gravels More than 50% retained on More than 50% of coarse fraction Less than 5% fines GP Poorly —graded gravels No. 200 sieve retained on No. 4 Sieve GRAVELS WITH FINES More than 12% fines GM Grovel and 'it Mixtures GC Grovel and Clay Mixtures SANDS CLEAN SANDS SW Well—groded Sands 50% or more of Less then 5% fines SP Poorly—groded Sands coarse fraction passes No. 4 Sieve SANDS WITH FINES SM Send and Silt Mixtures More than 12% fines SC Sand and Clay Mixtures FINE—GRAINED SOILS 50% or more passes the No. 200 sieve SILTS AND CLAYS Liquid limit less than 50 INORGANIC CL Low —plasticity Cloys ML Non —plastic and Low — Plasticity Silts Non—plostc and Low — ORGANIC OL Plasticity Organic Clays Non —plastic and Low — Plasticity Organic Silts SILTS AND CLAYS Liquid limit INORGANIC CH High —plasticity Clays MH High —plasticity Silts greater than 50 High —plasticity ORGANIC OH Organic Clays High —plasticity Organic Silts HIGHLY ORGANIC SOILS Primarily organic matter, dark in color, and organic odor PT Peat Relative Density or Consistency Utilizing Standard Penetration Test Values Cohesionless Soils (a) Cohesive Soils (b) (c) (c) Relative (c) Undroined (d) Density N. blows/ft. Density Consistency N. blows/ft. Shear Strength M (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 Compod 10 to 30 35 — 65 Firm 4 to 8 500-1000 Dense 30 to 50 65 — 65 Stiff 8 to 15 1000-2000 Very Dense over 50 >85 Very Stiff 15 to 30 2000-4000 Hard over 30 >4000 ' (a) Soils consisting of gravel, sand, and silt, either separately or in combination, possessing no characteristics of plasticity, end exhibiting drained behavior. (b) Soils possessing the characteristics of plasticity, and exhibiting undrained behavior. (c) Refer to text of ASTM D 1586-84 for a definition of N; in normally consolidated cohesionless soils Relative Density terms are based on N values corrected for overburden pressures. (d) Undrained shear strength - 1/2 unconfined compression strength. Descriptive Terminology Denoting Component Proportions Descriptive Terms Range of Proportion Trace 0-5% Little (a) 5-12% Some or Adjective 12-30% And 30-50% (a) Use Gravelly, Sandy or Silty as appropriate. Component Definitions by Gradation Component Size Range Boulders Above 12 in. Cobbles 3 in. to 12 in. I Gravel 3 in. to No. 4 (4.76mm) Coarse gravel 3 in. to 3/4 in. Fine grove: 3/4 in. to No. 4 (4.76mm) Sand No. 4 (4.76mm) to No. 200 (0.074mm) Coarse sand No. 4 (4.76mm) to No. 10 (2.Omm) Medium sand No. 10 (2.Omm) to No. 40 (0.42mm) Fine send No. 40 (0.42mm) to No. 200 (0.074mm) Silt and Cloy Smaller than No. 200 (0.074mm) Figure SOIL CLASSIFICATION/LEGEND Samples SS SPT Sampler (2.0' OD) HD Heavy Duty Split Spoon SH Shelby Tube P Pitcher Sampler 8 Bulk C Cored Unless otherwise noted, drive somp�es advanced with 140 lb. hommer witn 30 in. drop. Laboratory Tests Test Designation Moisture (1) Density D Groin Size G Hydrometer H Atlerberg Limits (1) Consolidation C Unconfined U UU Triax Uu CU Triax CU CD Triax CD Permeability P (1) Moisture and Atterberg Limits plotted on log. Silt and Clay Descriptions Description Typical Unified Designation Sill ML (non—plostic) Clayey Silt CL—ML (low plasticity) Silty Clay CL Clay CH Plastic Silt MH Organic Soils OL, OH, Pt �9° Golder Associates 773-1064/FORM 573 I il 1 PROJECT Renton/Highgate RECORD OF BOREHOLE BH-1 SHEET 1 OF? Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 O = SOILPROFILE SAMPLES PENETRATION RESISTANCE BLOWS/FT. PIEZOMETER 0 0 0 0 0 GRAPHIC w = ELEV. 2 BLOWS /6IN. z DESCRIPTION <n a ¢ O m w N a WATER CONTENT,PERCENT WATER a w O O <n a:O DEPTH a 140 lb. hammer O W ��y WI P LEVEL o co7) O z 30 inch drop 2 256.0 0 Forest duff Compact, light brown, nonstratified, fine to coarse SAND, trace angular gravel, some silt, damp (RECESSIONAL OUTWASH) 2.5 SM 1 SS 9-9-9 18 18/18 04.4 0 G 4.0 5 — — — —— 16.3 7.5 Compact, olive brown, nonstratlfied, silty, fine to SM 2 SS 5-6-7 13 18/18 0 ATD coarse SAND, trace gravel, iron stained, interbedded clayey silt lenses, moist to wet 9.0 < (RECESSIONAL OUTWASH) 10 x 18.4 12.5 SM 3 SS 6-7-11 18 18/18 0 14.0 15 17.5 SM 4 SS 35-40-50/6 >50 18/18 8.70 Boring Terminated @ 19.0 ftbgs 19.0 20 25 30 DRILL RIG: B-24 LOGGED: SLM DRILLING CONTRACTOR: Boretec CHECKED: DPF QVINFO .. Golder DRILLER: Rich DATE: 12/14/99 n' L I 1 i SHEET 1 OF 1 PROJECT: Renton/Highgate RECORD OF BOREHOLE BH-2 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 O = SOIL PROFILE SAMPLES PENETRATION RESISTANCE BLOWS/FT. PIEZOMETER 0 0 0 0 0 GRAPHIC w U ELEV BLOWS/61N. Z DESCRIPTION rn a m w N a WATER CONTENTPERCENT WATER a ¢ U ¢ DEPTH Z a 140lb. hammer w WI LEVEL 0 Co D 0 30 inch drop ccWp� 248.0 Forest duff ''; .; 0 Loose, dark brown, nonstratified, silty SAND, SM trace gravel, organics present as roots and wood, moist (FILL) Loose, olive brown, laminated, silty fine SAND, SM 2.5 iron stained, wet (RECESSIONAL OUTWASH) 1 SS 3-3-4 7 18/18 29.3 ATD 4.0 5 Q 2 v ..._..... 15.0 7.5 Dense, olive gray, nonstratified, silty fine to coarse SM 2 SS 20-26-15 41 18/18 0 SAND, little subrounded gravels, occasional iron staining, moist to wet (TILL) 9.0 10 13.5 12.5 SM 3 SS 20-23-18 41 18/18 0 Boring Terminated @ 14.0 ft bgs 14.0 15 20 25 30 DRILL RIG: B-24 LOGGED: SLM DRILLING CONTRACTOR: Boretec CHECKED: DPF_ DRILLER: Rich DATE: 12J17/99 A&sociaws I L SHEET 1 OF PROJECT Renton/Highgate RECORD OF BOREHOLE BH-3 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 O = SOIL PROFILE SAMPLES PENETRATION RESISTANCE BLOWS/FT. PIEZOMETER W W 0 90 0 0 0 GRAPHIC W LL v ELEV. BLOWS / 6 IN. a- z DESCRIPTION = w ED N ¢ WATER CONTENT,PERCENT WATER < DEPTH 2 a 140 lb. hammer U 2 W �J P` ' WI LEVEL o m c0 z 30 inch drop 251.0 Forest duff ---- — — — — — — a"riaa., ` 0 Loose, dark brown, nonstratified, silty SAND, organics present as roots and wood, moist to wet (FILL) 2.5 Compact, reddish olive brown, nonslratified, fine SM ATD to coarse SAND, little silt, wet (RECESSIONAL 1 SS 1-4-4 8 2'/18 18.80 OUTWASH) 4.0 5 Q 2 v coarsening with depth 7.5 SW 2 SS 8-9-11 18 18/18 D20.4 G 9.0 10 12.5 SM 3 SS 15-16-22 38 18/18 012.5 0 Boring Terminated ® 14.0 It bgs 14.0 15 20 25 30 DRILL RIG: B-24 LOGGED: SLM .. DRILLING CONTRACTOR: Borelec CHECKED: DPF Golder DRILLER: Rich DATE: 12/17/99 Ag;� I 1 SHEET 1 OF PROJECT Renton/Highgate RECORD OF BOREHOLE BH-4 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE' 10/4/99 0 0 x SOIL PROFILE SAMPLES PENETRATION RESISTANCE BLOWS/FT. ■ PIEZOMETER 0 0 0 0 0 GRAPHIC w = ELEV. Cr BLOWS / 6 IN. WATER CONTENT,PERCENT x t— (13 z DESCRIPTION 0 o_ ¢ m a N ¢ WATER w O ((0 C7 c- 0 DEPTH i 140lb. hammer U WI LEVEL c co CC 250.0 0 Forest duff Soft, dark brown, nonstratified, organic, fibrous PT PEAT, wood fragments, moist to wet (PEAT) ATD 2.5 Loose, olive brown, nonstratified, fine to coarse SW -_ 1 SS 4-3-3 6 18/18 ■ 023.9 132.2 SAND, trace silt, little organics, wet (RECESSIONAL OUTWASH) 4.0 5 U) a 19.5 7.5 SW 2 SS 5-8-11 19 18/18 9.0 10 Very dense, olive brown, nonstratified, silty SAND, little gravel, moist (TILL) 12.5 SM 3 SS 50/4' >50 4/18 011.4 Boring Terminated 14.0 If bgs 14.0 15 20 25 30 DRILL RIG: B-24 LOGGED: SLM VAR. DRILLING CONTRACTOR: Boretec CHECKED: DPF��� DRILLER: Rich DATE: 12/17/99 1 [l Ej [1 PROJECT: Renton/Highgate RECORD OF BOREHOLE BH-5 SHEET 1 OF 1 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 O 1:BLOWS/FT SOIL PROFILE SAMPLES PENETRATION RESISTANCE 0 PIEZOMETER 0 0 0 0 0 GRAPHIC w U ELEV 2 BLOWS / 6 IN. WATER CONTENT,PERCENT H Z DESCRIPTION cn a m Lu N ¢ WATER w O Um 2 G DEPTH a 1401b. hammer w W ��c WI p� LEVEL O m D c7 -' z 30 inch drop Cc 250.0 Soft, dark brown, nonstratified, organic, fibrous v 0 PEAT, little sand and wood fragments, moist to wet (PEAT) ATD 2.5 PT 1 SS 1-4-5 9 18/18 49.5 Loose, olive brown, nonstratified, organic SW - 4.0 CLAYEY SILT, little sand, organics present as roots and wood, wet (PEAT/ORGANIC SILT) -" 5 Compact, light brownish gray, nonstratified, silty = fine to coarse SAND, wet (RECESSIONAL v OUTWASH) 7.5 SM 2 SS 8-12-14 26 18/18 16.60 9.0 10 so 12.5 SM 3 SS 8-12-17 29 18/18 020.9 G Boring Terminated ® 14.0It bgs 14.0 15 20 25 30 DRILL RIG: B-24 LOGGED: SLM DRILLING CONTRACTOR: Borelec CHECKED: DPF Golder DRILLER: Rich DATE: 12/17/99 I u 1 I PROJECT: Renton/Highgate RECORD OF BOREHOLE BH-6 SHEET 1 OF 1 Sewer/WA DATUM: MSL PROJECT NUMBER: 993 1606 BORING LOCATION: Renton, Washington BORING DATE: 10/4/99 0 O x SOIL PROFILE SAMPLES PENETRATION RESISTANCE BLOyys/F ■ PIEZOMETER 0 0 0 0 GRAPHIC 0 W 2 O ELEV 2 BLOWS /6IN. Z DESCRIPTION cn o_ < m ur N ¢ WATER CONTENTPERCENT WATER EL WQ cc Occ U D O 0 DEPTH o- 140 lb. hammer U ¢ _ WP' yyl LEVEL z 30 inch drop 257.0 Loose, olive gray, nonstratified, mottled, fine to 0 medium SAND, little silt, trace gravel, iron staining, moist to wet (FILL) 2.5 SM 1 SS 4-3-3 6 18/18 ■ 19.3 4.0 ATD 5 Q x 0 19.8 25.2 7.5 Compact, olive gray, nonstratified, fine to medium SM:. 2 Ss 1-5-8 13 1 B/18 ■ o SAND, some silt, wet (RECESSIONAL 9.0 OUTWASH) 10 interbeds of laminated gray silt 12.5 SM 3 SS B-6-4 10 18/18 0 21.4 G Boring Terminated @ 14.0 ft bgs 14.0 15 20 25 30 DRILL RIG: B-24 LOGGED: SLM DRILLING CONTRACTOR: Boretec CHECKED: DPFGolder DRILLER: Rich DATE: 12/17/99 A.&.s. ocia*s Appendix 13 m r m m ■■r r m m w m w m m m w m m I I j 1� I fl I 1 [l APPENDIX B LABORATORY TEST RESULTS Golder Associates GOLDER ASSOCIATES, INC. -- REDMOND, WA MOISTURE CONTENT CALCULATION SHEET ASTM D-2216 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA PROJ. NO: 993-1606.200 DATE: 10/28/99 TECH: TCM REVIEW: TCM BORING SAMPLE DEPTH (ft) WET WT. (9) DRY WT. (9) TARE WT. TARE (9) NO. MOISTURE N BH-1 S-1 2.5 395.40 382.40 85.20 4.4 BH-1 S-2 7.5 451.70 401.00 90.20 16.3 BH-1 S-3 12.5 453.70 395.20 77.80 18.4 BH-1 S-4 17.5 457.20 427.70 88.30 8.7 BH-2 S-1 2.5 369.80 306.40 89.70 29.3 BH-2 S-2 7.5 565.00 503.00 89.90 15.0 BH-2 S-3 12.5 470.30 423.20 73.40 13.5 BH-3 S-2 7.5 593.90 506.60 78.90 20.4 BH-3 S-3 12.5 515.10 467.70 89.40 12.5 BH-4 S-1 up 2.5 190.20 137.60 97.80 132.2 BH-4 S-1low 2.5 384.20 327.60 90.90 23•9 BH-4 S-2 7.5 516.30 446.70 90.50 19.5 BH-4 S-3 12.5 238.90 225.50 108.30 11.4 BH-5 S-1 2.5 329.30 249.10 87.10 49.5 BH-5 S-2 7.5 583.90 516.00 107.00 16.6 BH-5 S-3 12.5 523.90 449.10 90.70 20.9 BH-6 S-1 2.5 466.80 406.00 91.20 19.3 BH-6 S-2 up 7.5 381.00 332.90 89.90 19.8 BH-6 S-2low 7.5 480.50 405.30 107.00 25.2 BH-6 S-3 12.5 468.80 405.10 107.00 21.4 BH-3 S-1 2.5 181.40 169.70 107.60 18.8 F1 GOLDER ASSOCIATES, INC. -- REDMOND, WA GRAIN SIZE ANALYSIS -- WASH SIEVE ASTM D1140 / D422 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA PROJECT NO: 993-1606.200 DATE: 11 /1 /99 TECH: TCM REVIEWER: TCM BOREHOLE BH-1 SAMPLE S-1 DEPTH (ft) 2.5-4 ` Description: Brownish Gray, F-M SAND, some silt, trace fine gravel ' USCS: SM tNATURAL MOISTURE C Gravel 0.0% ' Tare Number F Gravel 1.8% Wet Weight + Tare (g) 583.00 C Sand 8.1 % Dry Weight + Tare (g) 570.00 M Sand 44.4% Tare Weight (g) 272.80 F Sand 32.5% Water Content (%) 4.4% Fines 13.1 % Sieve Retained Passing (g) cum. tare 272.80 3" 272.80 100.0% LL 2" 272.80 100.0% PL 1" 272.80 100.0% PI 3/4" 272.80 100.0% 3/8" 274.70 99.4% #4 278.20 98.2% ' #10 302.40 90.0% #20 363.30 69.5% D10: 0.060 #40 434.40 45.6% D30: 0.15 ' #60 483.20 29.2% D60: 0.6 #100 508.20 20.8% Cu: N/A #200 531.10 13.1 % Cz: N/A 1 Ili MIMI M IM M M M M M M M- M MIMI= r r PARTICLE SIZE DISTRIBUTION US STANDARD SIEVE OPENING SIZES f t� c ca (L 01 ° Coarse I Fine GRAVEL A")n �mn *60 0100 #200 Grain Size (mm) Coarse I Medium I Fine SAND FINES (Silt or Clay) DEPTH ft W% LL PL PI USCS DESCRIPTION SAMPLE ID BH-1 2.5-4 4.4% SM Brownish Gray, F-M SAND, S-1 some silt, trace fine gravel 0 PROJECT: CITY OF RENTON ] HIGHGATE SEWER / WA GOLDER ASSOCIATES, INC. PROJECT NO.: 993-1606.200 DATE: 11/1/99 TECH: TCM REVIEW: TCM REDMOND, WA GOLDER ASSOCIATES, INC. -- REDMOND, WA GRAIN SIZE ANALYSIS -- WASH SIEVE ASTM D1140 / D422 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA PROJECT NO: 993-1606.200 DATE: 11 /1 /99 TECH: TCM REVIEWER: TCM BOREHOLE BH-3 SAMPLE S-2 DEPTH (ft) 7.5-9 ' Description: Light Yellowish Brown, F-M SAND, little silt, trace f gravel USCS: SW u NATURAL MOISTURE Tare Number Wet Weight + Tare (g) Dry Weight + Tare (g) Tare Weight (g) Water Content (%) 825.40 738.10 310.40 20.4% C Gravel F Gravel C Sand M Sand F Sand Fines 0.0% 1.5% 4.8% 35.1 48.7% 9.9% Sieve Retained Passing (g) cum. tare 310.40 3" 310.40 100.0% LL 2" 310.40 100.0% PL 1 " 310.40 100.0% PI 3/4" 310.40 100.0% 3/8" 310.40 100.0% #4 316.80 98.5% #10 337.20 93.7% #20 394.20 80.4% D10: 0.075 #40 487.40 58.6% D30: 0.25 #60 608.80 30.2% D60: 0.4 #100 668.60 16.2% Cu: 5.9 #200 695.90 9.9% Cz: 1.9 m m m m m lip i w s �■� i� a~ l� i r� PARTICLE SIZE DISTRIBUTION US STANDARD SIEVE OPENING SIZES f 01) C N co (C 0- NO — ... .. oIA- aia- d #1n #20 #40 #60 #100 #200 Grain Size (mm)' Coarse Fine Coarse Medium Fine GRAVEL SAND FINES (Silt or Clay) SAMPLE ID DEPTH ft W% LL PL PI USCS DESCRIPTION BH-3 7.5-9 20.4% SW Light Yellowish Brown, F-M SAND, S-2 little silt, trace f gravel 0 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA GOLDER ASSOCIATES, INC. PROJECT NO.: 993-1606.200 DATE: 11 /1 /99 TECH: TCM REVIEW: TCM REDMOND, WA I .. C GOLDER ASSOCIATES, INC. -- REDMOND, WA GRAIN SIZE ANALYSIS -- WASH SIEVE ASTM D1140 / D422 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA PROJECT NO: 993-1606.200 DATE: 11 /1 /99 TECH: TCM REVIEWER: TCM BOREHOLE BH-5 SAMPLE S-3 DEPTH (ft) 12.5-14 Description: Light Brownish Gray, silty fine to medium sand USCS: I SM NATURAL MOISTURE Tare Number Wet Weight + Tare (g) Dry Weight + Tare (g) Tare Weight (g) Water Content (%) 748.00 673.20 314.80 20.9% C Gravel F Gravel C Sand M Sand F Sand Fines 0.0% 0.0% 0.6% 11.90 39.2% 48.4% Sieve Retained Passing (g) cum. tare 314.80 3" 314.80 100.0% LL 2" 314.80 100.0% PL 1" 314.80 100.0% PI 3/4" 314.80 100.0% 3/8" 314.80 100.0% #4 314.80 100.0% #10 316.80 99.4% #20 324.70 97.2% D10: 0.004 #40 359.30 87.6% D30: 0.02 #60 430.60 67.7% D60: *NJA #100 468.30 57.2% Cu:#200 499.70 48.4% Cz: 0 c U) ca a- Coarse I Fine GRAVEL PARTICLE SIZE DISTRIBUTION US STANDARD SIEVE OPENING SIZES . 4 n Mon stdn �vRn ill no #200 Grain Size (mm) Coarse I Medium I Fine SAND FINES (Silt or Clay) DEPTH ft W% LL PL PI USCS DESCRIPTION SAMPLE ID 131-1-5 S-3 12.5-14 20.9% SM Light Brownish Gray, silty fine to medium sand 0 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA GOLDER ASSOCIATES, INC. PROJECT NO.: 993-1606.200 DATE: 11/1/99 TECH: TCM REVIEW: TCM REDMOND, WA GOLDER ASSOCIATES, INC. -- REDMOND, WA GRAIN SIZE ANALYSIS -- WASH SIEVE ASTM D1140 / D422 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA PROJECT NO: 993-1606.200 DATE: 11 /1 /99 TECH: TCM REVIEWER: TCM BOREHOLE BH-6 SAMPLE S-3 DEPTH (ft) 12.5-14 Description: Gray, F SAND, some silt USCS: SM NATURAL MOISTURE Tare Number Wet Weight + Tare (g) Dry Weight + Tare (g) Tare Weight (g) Water Content (%) 674.40 610.70 312.60 F--21.4%1 C Gravel F Gravel C Sand M Sand F Sand Fines 0.0% 0.0% 0.2% 2.1 % 77.0% Sieve Retained Passing (g) cum. tare 312.60 3" 312.60 100.0% LL 2" 312.60 100.0% PL 1" 312.60 100.0% PI 3/4" 312.60 100.0% 3/8" 312.60 100.0% #4 312.60 100.0% #10 313.10 99.8% #20 314.00 99.5% D10: 0.060 #40 319.40 97.7% D30: 0.09 #60 339.00 91.1 % D60: 0.2 #100 419.50 64.1 % Cu: N/A #200 548.80 20.8% Cz: N/A 0 a) c U) cu Q. 0- 0 PARTICLE SIZE DISTRIBUTION US STANDARD SIEVE OPENING SIZES AAin W51n *40 #60 #100 #200 Grain Size (mm) Coarse Fine Coarse Medium Fine FINES (Silt or Clay) GRAVEL SAND SAMPLE ID DEPTH ft W% LL PL PI USCS DESCRIPTION 131-1-6 12.5-14 21.4% SM Gray, F SAND, some silt S-3 0 PROJECT: CITY OF RENTON / HIGHGATE SEWER / WA GOLDER ASSOCIATES, INC. PROJECT NO.: 993-1606.200 DATE: 11/1/99 TECH: TCM REVIEW: TCM REDMOND, WA