geotechnical engineering services - des.wa.gov · figure b-1 through b-6 – sieve analysis results...

Geotechnical Engineering Services

Allied Health and Manufacturing Buildings Shoreline Community College Shoreline, Washington

for Shoreline Community College

May 15, 2018

17425 NE Union Hill Road, Suite 250 Redmond, Washington 98052 425.861.6000

Geotechnical Engineering Services

Allied Health and Manufacturing Buildings Shoreline Community College

Shoreline, Washington File No. 8030-010-00

May 15, 2018

Prepared for:

Washington State Department of Enterprise Services Division of Engineering & Architectural Services 1500 Jefferson Street SE Olympia, Washington 98504

Attention: Jonathan Martin

Prepared by:

GeoEngineers, Inc. 17425 NE Union Hill Road, Suite 250 Redmond, Washington 98052 425.861.6000

Kyle M. Smith, PE Geotechnical Engineer

Robert C. Metcalfe, PE, LEG Principal

EFT:RCM:nld

Disclaimer: Any electronic form, facsimile or hard copy of the original document (email, text, table, and/or figure), if provided, and any attachments are only a copy of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record.

May 15, 2018 | Page i File No. 8030-010-00

Table of Contents INTRODUCTION ....................................................................................................................................................... 1

Project Description ............................................................................................................................................. 1 Purpose and Scope ............................................................................................................................................ 1

FIELD EXPLORATIONS AND LABORATORY TESTING ........................................................................................... 1

Field Explorations ............................................................................................................................................... 1 Laboratory Testing ............................................................................................................................................. 2 Previous Site Explorations ................................................................................................................................. 2

SITE DESCRIPTION ................................................................................................................................................. 2

Surface Conditions............................................................................................................................................. 2 Subsurface Soil Conditions ............................................................................................................................... 3 Groundwater Conditions .................................................................................................................................... 3

CONCLUSIONS AND RECOMMENDATIONS .......................................................................................................... 3

Earthwork ........................................................................................................................................................... 4 Clearing and Site Preparation .................................................................................................................... 4 Subgrade Preparation ................................................................................................................................. 5 Structural Fill ............................................................................................................................................... 6 Utility Trenches ............................................................................................................................................ 8 Pavement Subgrade Preparation ............................................................................................................... 9 Sedimentation and Erosion Control ........................................................................................................... 9

Excavations ........................................................................................................................................................ 9 Temporary Cut Slopes ............................................................................................................................... 10

Foundations ..................................................................................................................................................... 10 Foundation Design .................................................................................................................................... 10 Foundation Settlement ............................................................................................................................. 11 Lateral Resistance .................................................................................................................................... 11 Construction Considerations .................................................................................................................... 11 Footing Drains ........................................................................................................................................... 12

Below-Grade Walls and Retaining Walls ......................................................................................................... 12 Design Parameters ................................................................................................................................... 12 Wall Drainage ............................................................................................................................................ 13 Other Considerations ................................................................................................................................ 13

Slab-on-Grade Floor ......................................................................................................................................... 13 Subgrade Preparation ............................................................................................................................... 13 Design Parameters ................................................................................................................................... 13

Earthquake Engineering .................................................................................................................................. 14 2015 IBC Seismic Design Information .................................................................................................... 14

Geologic Hazards ............................................................................................................................................. 14 Infiltration Considerations ............................................................................................................................... 14

Grain-size Analyses ................................................................................................................................... 14 Pilot Infiltration Tests ................................................................................................................................ 15

Drainage Considerations ................................................................................................................................. 16

Page II

Recommended Additional Geotechnical Services ......................................................................................... 16

LIMITATIONS ......................................................................................................................................................... 16

REFERENCES ....................................................................................................................................................... 17

LIST OF FIGURES

Figure 1. Vicinity Map Figure 2. Site Plan – AH&M Buildings Figure 3. Site Plan – Greenwood Infiltration Facility Figure 4. Cross Section A-A’ – Greenwood Infiltration Facility Figure 5. Cross Section B-B’ – Greenwood Infiltration Facility Figure 6. Wall Drainage and Backfill Figure 7. Compaction Criteria for Trench Backfill

APPENDICES

Appendix A. Field Explorations Figure A-1 – Key to Exploration Logs Figures A-2 through A-16 – Logs of Borings

Appendix B. Laboratory Testing Figure B-1 through B-6 – Sieve Analysis Results

Appendix C. Previous Exploration Appendix D. Report Limitations and Guidelines for Use

May 15, 2018 | Page 1 File No. 8030-010-00

INTRODUCTION

This report presents the results of GeoEngineers’ geotechnical engineering services for the proposed Allied Health and Manufacturing Buildings and the Greenwood Infiltration Pond located on the Shoreline Community College campus in Shoreline, Washington. The project location is shown on Figure 1, Vicinity Map and the layout of the project is shown relative to existing improvements on the Site Plans (Figures 2 and 3).

Project Description

Our understanding of the project is based on discussions with and information provided by Schacht Aslani Architects.

The Allied Health and Manufacturing Buildings (AH&M) project is located in the north portion of Shoreline Community College located at 16101 Greenwood Avenue North in Shoreline, Washington. The project consists of demolishing four existing one-story academic buildings (2400, 2600, 2700, and 2800) during Phase 1 when the Allied Health Building will be constructed, and then demolishing Building 2500 during Phase 2 when the Manufacturing Building will be constructed. We understand that the proposed Manufacturing Building will be constructed at grade with no below-grade structures, while the Allied Health Building will have two to three levels and will be cut into the slope with the lower level daylighting to the north and matching the Manufacturing Building finished grade.

The project will also include construction of a stormwater infiltration/detention facility in the Greenwood Parking Lot located northeast of the campus adjacent to Boeing Creek. The location of the facility is shown on Figure 3 and we understand that the pond will extend at least 8 feet deep and will have 3H:1V (horizontal to vertical) side slopes. Other site improvements include new pedestrian walkways, underground utilities, pavement, and landscape areas.

Purpose and Scope

The purpose of our services is to evaluate soil and groundwater conditions as a basis for developing design criteria and construction recommendations for the geotechnical aspects of the project. Field explorations were performed to identify and evaluate subsurface conditions at the site in order to develop engineering recommendations for use in design of the project. Our geotechnical engineering services were completed in general accordance with our proposal dated February 19, 2018.

FIELD EXPLORATIONS AND LABORATORY TESTING

Field Explorations

Subsurface conditions at the site were evaluated by drilling 15 borings (B-1 through B-15) to depths of 21.5 to 51.5 feet below the ground surface on March 8, 19, and 20, 2018. Borings B-1 through B-10 were drilled for the planned buildings, while Borings B-11 through B-15 were drilled in the Greenwood parking lot for the proposed stormwater infiltration facility. A monitoring well was installed in boring B-12 in the Greenwood Parking Lot to allow measurement of groundwater levels following drilling. The locations of the borings are shown on Figures 2 and 3. Locations of the borings were determined in the field by measuring to existing features. Ground surface elevations at the boring locations were estimated from the site survey

May 15, 2018 | Page 2 File No. 8030-010-00

map provided by Schacht Aslani Architects. Descriptions of the subsurface exploration program and logs of the borings are presented in Appendix A, Field Explorations.

Laboratory Testing

Soil samples were collected during the exploration program and taken to our laboratory for further evaluation and laboratory testing. Selected samples were tested for moisture content, fines content (percent passing the U.S. No. 200 sieve) and grain size distribution. A description of the laboratory testing and the test results are presented in Appendix B.

Previous Site Explorations

In addition to the explorations completed as part of this project, we reviewed logs of available explorations from previous studies in the project areas. The logs of explorations from previous projects referenced for this study are presented in Appendix C, Previous Explorations, and shown on Figures 2 and 3.

SITE DESCRIPTION

Surface Conditions

The proposed AH&M buildings are located in the north end of the campus in the vicinity of buildings 2500 through 2800. The proposed infiltration pond is located in the Greenwood parking lot downslope of the northeast corner of the campus.

The topography in the vicinity of the proposed AH&M buildings is shown on Figure 2. The ground surface in the existing building areas is relatively flat with the exception of an approximate 10-foot elevation change between Buildings 2500 and 2600. Underground utilities include water, gas, sewer, and storm, as well as communications and power are located in the vicinity of the existing buildings where the AH&M buildings will be constructed. Vegetation at the AH&M site consists of low ground cover, trees and shrubs in landscaping areas around the existing buildings.

The topography in the vicinity of the proposed infiltration pond is shown on Figure 3. The existing Greenwood parking lot where the storm water facility is planned is relatively flat between about Elevation 365 feet at the south end to about Elevation 360 feet at the north end. The slope located between the campus and the parking lot is about 100 feet high and is forested with conifer trees and a thick understory. A detention facility along Boeing Creek is located immediately east and downslope of the proposed stormwater infiltration facility. The slope descends about 30 feet from the parking lot down to the bottom of the detention facility. The upper portion of the slope appears to be constructed from fill that was likely cut from other areas of the parking lot to develop the flat parking surface. The parking lot is surfaced with crushed gravel.

May 15, 2018 | Page 3 File No. 8030-010-00

Subsurface Soil Conditions

This site is mapped as underlain by advance outwash (Minard 1983) and the borings indicate soil conditions consistent with the geologic mapping. Two cross sections illustrating the subsurface conditions in the Greenwood Stormwater Facility area are shown on Figures 4 and 5. Soils observed during drilling are summarized below.

■ Fill/Recessional Outwash:

Allied Health Building - Fill and possible recessional outwash soils consisting of loose to medium dense silty sand with gravel was observed in Borings B-1 through B-4 from 4 to 7 feet below the existing ground surface. No fill was encountered in Boring B-5.

Manufacturing Building - Fill and possible recessional outwash soils consisting of loose to medium dense silty sand with gravel was observed in Borings B-7 through B-9 from 4 to 6.5 feet below the existing ground surface. No fill was observed in Borings B-6 and B-10.

Greenwood Stormwater Facility - Fill soils consisting of loose to medium dense sand with silt to silty sand with variable gravel was observed in Borings B-11 through B-15 from about 8 to 14 feet below the existing parking lot surface, as shown in Figures 4 and 5.

■ Advance Outwash: Advance outwash consisting of medium dense to very dense fine to medium sand with silt and gravel was encountered in all of the borings either near the ground surface or below the fill soils described above. The advance outwash was weathered within the upper 2 to 5 feet of the deposits and extended to the depths explored (21.5 to 51.5 feet).

Groundwater Conditions

Groundwater was not observed in any of the explorations during drilling. A groundwater monitoring well was installed in Boring B-12 along the west side of the Greenwood stormwater facility and no water was observed in the well immediately after installation including measurements made the following day. Groundwater levels and possible perched groundwater seepage will vary as a function of season, precipitation and other factors.

CONCLUSIONS AND RECOMMENDATIONS

Based on the results of our subsurface exploration program, geotechnical laboratory testing, analyses, and experience on other projects within the Shoreline Community College campus, we conclude that the proposed AH&M project can be constructed satisfactorily as planned with respect to geotechnical elements. A summary of key geotechnical issues for the project include the following:

■ The AH&M Buildings can be designed as Site Class C per the 2015 International Building Code (IBC).

■ Conventional slabs-on-grade are considered appropriate and should be underlain by a 4-inch-thick layer of capillary break consisting of clean crushed gravel.

■ Foundations that bear on undisturbed dense to very dense advance outwash soils may be designed using an allowable bearing pressure of 6,000 pounds per square foot (psf) for shallow spread footings. Foundations bearing on structural fill placed on medium dense to dense native soils may be designed using an allowable bearing pressure of 3,000 psf.

May 15, 2018 | Page 4 File No. 8030-010-00

■ Excavations up to about 10 feet below site grades are planned for the development. Depending on site constraints excavation support can likely be provided by using temporary cut slopes.

■ Based on our observations, the regional groundwater table is below the planned depth of excavation for the buildings and temporary dewatering can be completed using sumps and pumps.

■ Conventional below-grade wall and slab drainage can be utilized for walls and slabs-on-grade. A below-slab underdrain pipe is recommended below the lower floor slab for the Allied Health Building since it will be cut into the hill slope. Flows into the underslab drainage system are estimated to be less than 10 gallons per minute (gpm).

■ Subsurface soil conditions below the proposed Greenwood stormwater facility are suitable for infiltration into the native outwash soils. Based on the subsurface explorations, suitable native outwash is typically located approximately 8 to 12 feet deep, although up to 14 feet of excavation may be needed in localized areas. The bottom of the infiltration facility should extend into native advance outwash and through observed fill consisting of silty sand. For preliminary design purposes and based on the grain size tests results, design infiltration rates range from 1.2 to 8.5 inches per hour at depths of 10 to 15 feet. In-situ pilot infiltration testing should be conducted based on the final geometry of the pond. Groundwater was not observed within 40 feet of the planned pond bottom and therefore groundwater mounding analyses are likely not needed unless impacts to the adjacent Boeing Creek detention facility require modelling.

Earthwork

Based on the subsurface soil conditions encountered in the borings, we anticipate that the soils at the site may be excavated using conventional heavy-duty construction equipment. Materials we encountered are generally medium dense to very dense. The native outwash soils typically become very dense at depths of less than 10 feet and may be difficult to excavate. Advance outwash deposits in the area commonly contain cobbles and boulders that may be encountered during excavation. Accordingly, the contractor should be prepared to deal with cobbles and boulders, if encountered.

The fill contains sufficient fines (material passing the U.S. Standard No. 200 sieve) to be highly moisture-sensitive and susceptible to disturbance, especially when wet. Ideally, earthwork should be undertaken during extended periods of dry weather when the surficial soils will be less susceptible to disturbance and provide better support for construction equipment. Dry weather construction will help reduce earthwork costs and increase the potential for using the native soils as structural fill.

Trafficability on the site is not expected to be difficult during dry weather conditions. However, the native soils will be susceptible to disturbance from construction equipment during wet weather conditions and pumping and rutting of the exposed soils under equipment loads may occur and could potentially generate significant quantities of mud if not protected.

Clearing and Site Preparation

Construction of the buildings and stormwater facility will require demolition of existing facilities, clearing and stripping. We expect that there will be demolition of existing buildings and foundation elements, asphalt pavement, sidewalks, curbs, light poles, and utilities. Concrete rubble and asphalt pavement may be recycled and reused as structural fill, otherwise it should be removed from the site along with other

May 15, 2018 | Page 5 File No. 8030-010-00

construction debris. Based on our explorations and site observations, the asphalt pavement is 1½ to 2 inches thick. All existing utilities should be removed from the building footprint and be rerouted if needed.

Areas to be developed or graded should be cleared of surface and subsurface deleterious matter including debris, shrubs, trees and associated stumps and roots. Graded areas should be stripped of organic materials and topsoil. Based on our explorations and site observations, we estimate that stripping depths will be on the order of 3 to 6 inches to remove topsoil within existing landscape areas. Greater stripping depths will be needed in more densely vegetated areas and where large tree root systems exist.

The stripped organic soils can be stockpiled and used later for landscaping purposes or may be spread over disturbed areas following completion of grading. If spread out, the organic strippings should be placed in a layer less than 1 foot thick, should not be placed on slopes greater than 3H:1V and should be track-rolled to a uniformly compacted condition. Materials that cannot be used for landscaping or protection of disturbed areas should be removed from the project site.

Subgrade Preparation

Fill soils associated with grading, underground utilities, and landscaping should be removed from below the building footprints.

Prior to placing new fills, pavement base course materials or gravel below on-grade floor slabs, subgrade areas should be proofrolled to locate any areas of soft or pumping soils. Proofrolling can be completed using a piece of heavy tire-mounted equipment such as a loaded dump truck. During wet weather, the exposed subgrade areas should be probed to determine the extent of soft soils. If soft or pumping soils are observed they should be removed and replaced with structural fill.

If deep pockets of soft or pumping soils are encountered outside the building areas, it may be possible to limit the depth of overexcavation by placing a non-woven geotextile separator such as Mirafi 500X (or similar material) on the overexcavated subgrade prior to placing structural fill. The geotextile will provide additional support by bridging over the soft material and will help reduce fines contamination into the structural fill.

After completing the proofrolling, the subgrade areas should be recompacted to a firm and unyielding condition, if possible. The degree of compaction that can be achieved will depend on when the construction is performed. If the work is performed during dry weather conditions, we recommend that all subgrade areas be recompacted to at least 95 percent of the maximum dry density (MDD) in accordance with the American Society for Testing and Materials (ASTM) D1557 test procedure (modified Proctor). If the work is performed during wet weather conditions, it may not be possible to recompact the subgrade to 95 percent of the MDD. In this case, we recommend that the subgrade be compacted to the extent possible without causing undue weaving or pumping of the subgrade soils.

Subgrade disturbance or deterioration could occur if the subgrade is wet and cannot be dried. If the subgrade deteriorates during proofrolling or compaction, it may become necessary to modify the proofrolling or compaction criteria or methods.

May 15, 2018 | Page 6 File No. 8030-010-00

Structural Fill

All fill, whether existing on-site advance outwash soil or imported soil, that will support floor slabs, pavement areas or foundations, or be placed against retaining walls or in utility trenches are classified as structural fill and should generally meet the criteria for structural fill presented below. The suitability of soil for use as structural fill depends on its gradation and moisture content.

Materials Structural fill material quality varies depending upon its use as described below:

1. Building foundations designed for 3,000 psf or lower bearing pressure should be supported on structural fill consisting of recompacted on-site soils or imported gravel borrow per Washington State Department of Transportation (WSDOT) Section 9-03.14(1). Foundations design for foundation bearing pressures higher than 3,000 psf should be supported on dense to very dense native outwash or on controlled density fill (CDF) extending to dense native soils.

2. Structural fill placed to construct parking areas, to backfill utility trenches, placed against below-grade walls, and to support building floor slabs may consist of on-site advance outwash provided that the soils are moisture conditioned for the required compaction. On-site outwash soils will be suitable for use as structural fill during dry weather conditions in areas needing 95 percent compaction. It may be possible to use on-site outwash soils during wet weather for areas requiring only 90 percent compaction provided the earthwork contractor implements good wet weather techniques. If structural fill is placed during wet weather, the structural fill should consist of imported gravel borrow as described in Section 9-03.14(1) of the 2018 WSDOT Standard Specifications, with the additional restriction that the fines content be limited to no more than 5 percent.

3. CDF used to support building foundations designed for bearing pressures exceeding 3,000 psf should be in accordance with 2018 WSDOT Standard Specification Section 2-09.3(1)E and should have a minimum compressive strength of 200 pounds per square inch (psi). The mix design should be adjusted to obtain this minimum compressive strength.

4. Structural fill placed immediately outside below-grade walls (drainage zone) should consist of washed ⅜-inch to No. 8 pea gravel or conform to Section 9-03.12(4) of the 2018 WSDOT Standard Specifications, as shown on Figure 6, Wall Drainage and Backfill.

5. Structural fill placed as crushed surfacing base course below pavements should conform to Section 9-03.9(3) of the 2018 WSDOT Standard Specifications.

6. Structural fill placed as capillary break below slabs should consist of 1-inch minus clean crushed gravel with negligible sand or silt in conformance with Section 9-03.1(4)C, grading No. 67 of the 2018 WSDOT Standard Specifications.

Reuse of On-site Native Soils The outwash soils contain a high percentage of fines and will be sensitive to changes in moisture content and difficult to handle and compact during wet weather.

The medium dense to very dense native advance outwash deposits are expected to be suitable for reuse as structural fill in areas requiring compaction to at least 95 percent of MDD (per ASTM D 1557), provided the work is accomplished during the normally dry season (June through September) and that the soil can be properly moisture conditioned. Imported structural fill consisting of sand and gravel (WSDOT gravel

May 15, 2018 | Page 7 File No. 8030-010-00

borrow) should be planned under all building floor slabs and foundation elements (3,000 psf bearing pressure or less) and as wall backfill if construction occurs during wet weather.

The use of existing on-site outwash soils as structural fill during wet weather should be planned only for areas requiring compaction to 90 percent of MDD, as long as the soils are properly protected from wet weather and not placed during periods of precipitation. The contractor should plan to cover and maintain all fill stockpiles with plastic sheeting if it will be used as structural fill. The reuse of on-site soils is highly dependent on the skill of the contractor and schedule, and we will work with the design team and contractor to maximize the reuse of on-site outwash soils during the wet and dry seasons.

Fill Placement and Compaction Criteria Structural fill should be mechanically compacted to a firm, non-yielding condition. Structural fill should be placed in loose lifts not exceeding 12 inches in thickness if using heavy compactors and 6 inches if using hand operated compaction equipment. The actual lift thickness will be dependent on the structural fill material used and the type and size of compaction equipment. Each lift should be moisture conditioned to within 2 percent of the optimum moisture content and compacted to the specified density before placing subsequent lifts. Compaction of all structural fill at the site should be in accordance with the ASTM D 1557 (modified proctor) test method. Structural fill should be compacted to the following criteria:

1. Structural fill placed below floor slabs and foundations, and against foundations, should be compacted to at least 95 percent of the MDD.

2. Structural fill placed behind below-grade walls should be compacted to between 90 to 92 percent of the MDD. Care should be taken when compacting fill near the face of below-grade walls to avoid over-compaction and hence overstressing the walls. Hand operated compactors should be used within 5 feet behind the wall. Wall backfill placed within the building footprint, but under a second-floor level should be compacted to between 90 to 92 percent of the MDD within 5 feet of the walls and to at least 95 percent of the MDD beyond 5 feet of the walls. The upper 2 feet of fill below floor slab subgrade should also be compacted to at least 95 percent of the MDD. The contractor should keep all heavy construction equipment away from the top of retaining walls a distance equal to half the height of the wall, or at least 5 feet, whichever is greater.

3. Structural fill in new pavement and hardscape areas, including utility trench backfill, should be compacted to at least 90 percent of the MDD, except that the upper 2 feet of fill below final subgrade should be compacted to at least 95 percent of the MDD, see Figure 7, Compaction Criteria for Trench Backfill.

4. Structural fill placed as crushed rock base course below pavements should be compacted to 95 percent of the MDD.

5. Non-structural fill, such as fill placed in landscape areas, should be compacted to at least 90 percent of the MDD.

Weather Considerations Disturbance of near surface soils should be expected if earthwork is completed during periods of wet weather. During dry weather the soils will: (1) be less susceptible to disturbance, (2) provide better support for construction equipment, and (3) be more likely to meet the required compaction criteria.

May 15, 2018 | Page 8 File No. 8030-010-00

The wet weather season generally begins in October and continues through May in western Washington; however, periods of wet weather may occur during any month of the year. For earthwork activities during wet weather, we recommend that the following steps be taken:

1. The ground surface in and around the work area should be sloped so that surface water is directed away from the work area. The ground surface should be graded so that areas of ponded water do not develop. Measures should be taken by the contractor to prevent surface water from collecting in excavations and trenches. Measures should be implemented to remove surface water from the work area.

2. Earthwork activities should not take place during periods of moderate to heavy precipitation.

3. Slopes with exposed soils should be covered with plastic sheeting.

4. The contractor should take necessary measures to prevent on-site soils and soils to be used as fill from becoming wet or unstable. These measures may include the use of plastic sheeting, sumps with pumps, and grading. The site soils should not be left uncompacted and exposed to moisture. Sealing the surficial soils by rolling with a smooth-drum roller prior to periods of precipitation will help reduce the extent that these soils become wet or unstable.

5. The contractor should cover all soil stockpiles that will be used as structural fill with plastic sheeting.

6. Construction traffic should be restricted to specific areas of the site, preferably areas that are surfaced with the existing asphalt or working pad materials not susceptible to wet weather disturbance.

7. Construction activities should be scheduled so that the length of time that soils are left exposed to moisture is reduced to the extent practical.

Routing of equipment on the existing fill and native outwash subgrade soils during the wet weather months will be difficult and the subgrade will likely become highly disturbed and rutted. In addition, a significant amount of mud can be produced by routing equipment directly on the fill and outwash soils in wet weather. Therefore, to protect the subgrade soils and to provide an adequate wet weather working surface for the contractor’s equipment and labor, we recommend that the contractor protect exposed subgrade soils with sand and gravel, crushed gravel, or asphalt-treated base (ATB).

Utility Trenches

Trench excavation, pipe bedding, and trench backfilling should be completed using the general procedures described in the 2018 WSDOT Standard Specifications, or as specified by the project civil engineer. The native glacial deposits and fill soils encountered at the site are generally of low corrosivity based on our experience in the Puget Sound area.

Utility trench backfill should consist of structural fill and should be placed in lifts of 12 inches or less (loose thickness) when using heavy compaction equipment, and 6 inches or less when using hand compaction equipment, such that adequate compaction can be achieved throughout the lift. Each lift must be compacted prior to placing the subsequent lift. Prior to compaction, the backfill should be moisture conditioned to within 2 percent of the optimum moisture content. The backfill should be compacted in accordance with the criteria discussed above. Figure 7 illustrates recommended trench compaction criteria under pavement and non-structural areas.

May 15, 2018 | Page 9 File No. 8030-010-00

Pavement Subgrade Preparation

We recommend that the subgrade soils in new pavement areas be prepared and evaluated as described in the “Earthwork” section of this report. In cut areas in dense to very dense native outwash soils, we recommend that the exposed subgrade be proof-rolled. Where existing fill or loose to medium dense native soils exist, we recommend that the upper 12 inches of the existing site soils be compacted to at least 95 percent of the MDD per ASTM D1557 and then proof-rolled prior to placing pavement section materials. If the subgrade soils are loose or soft, it may be necessary to excavate the soils and replace them with structural fill, gravel borrow, or gravel base material. Based on our explorations, the majority of the subgrade soils are expected to consist of medium dense to very dense advance outwash. Pavement subgrade conditions should be observed and proofrolled during construction to evaluate the presence of unsuitable subgrade soils and the need for over-excavation and placement of a geotextile separator.

Sedimentation and Erosion Control

In our opinion, the erosion potential of the on-site soils is low. Construction activities including stripping and grading will expose soils to the erosional effects of wind and water. The amount and potential impacts of erosion are partly related to the time of year that construction actually occurs. Wet weather construction will increase the amount and extent of erosion and potential sedimentation.

Erosion and sedimentation control measures may be implemented by using a combination of interceptor swales, straw bale barriers, silt fences, and straw mulch for temporary erosion protection of exposed soils. All disturbed areas should be finish graded and seeded as soon as practicable to reduce the risk of erosion. Erosion and sedimentation control measures should be installed and maintained in accordance with the requirements of the City of Shoreline.

Excavations

Excavations for the lower level of the AH&M building may require cuts up to about 10 feet deep. Temporary open cut slopes will likely be used to complete the excavations. Excavations are also required for underground utilities and the Greenwood stormwater facility. The stability of open cut slopes is a function of soil type, groundwater seepage, slope inclination, slope height and nearby surface loads. The use of inadequately designed open cuts could impact the stability of adjacent work areas, existing utilities, and endanger personnel.

The contractor performing the work has the primary responsibility for protection of workers and adjacent improvements. In our opinion, the contractor will be in the best position to observe subsurface conditions continuously throughout the construction process and to respond to variable soil and groundwater conditions. Therefore, the contractor should have the primary responsibility for deciding whether or not to use open cut slopes for much of the excavations rather than some form of temporary excavation support, and for establishing the safe inclination of the cut slope. Acceptable slope inclinations for utilities and ancillary excavations should be determined during construction. Because of the diversity of construction techniques and available shoring systems, the design of temporary shoring is most appropriately left up to the contractor proposing to complete the installation. Temporary cut slopes and shoring must comply with the provisions of Title 296 Washington Administration Code (WAC), Part N, “Excavation, Trenching and Shoring.”

May 15, 2018 | Page 10 File No. 8030-010-00

Temporary Cut Slopes

For planning purposes, temporary unsupported cut slopes more than 4 feet high may be inclined at 1H:1V maximum steepness within the dense to very dense advance outwash and 1.5H:1V maximum steepness in the fill soils. If significant seepage is present on the cut face then the cut slopes may have to be flattened. However, temporary cuts should be discussed with the geotechnical engineer during final design development to evaluate suitable cut slope inclinations for the various portions of the excavation. The contractor should scale slopes cut at 1H:1V to remove loose materials and cobbles.

The above guidelines assume that surface loads such as traffic, construction equipment, stockpiles or building supplies will be kept away from the top of the cut slopes a sufficient distance so that the stability of the excavation is not affected. We recommend that this distance be at least 5 feet from the top of the cut for temporary cuts made at 1H:1V or flatter, and no closer than a distance equal to one half the height of the slope for cuts made steeper than 1H:1V.

Temporary cut slopes should be planned such that they do not encroach on a 1H:1V influence line projected down from the edges of nearby or planned foundation elements. New footings planned at or near existing grades and in temporary cut slope areas for the lower level should extend through wall backfill and be embedded in native soils.

Water that enters the excavation must be collected and routed away from prepared subgrade areas. We expect that this may be accomplished by installing a system of drainage ditches and sumps along the toe of the cut slopes. Some sloughing and raveling of the cut slopes should be expected. Temporary covering, such as heavy plastic sheeting with appropriate ballast, should be used to protect these slopes during periods of wet weather. Surface water runoff from above cut slopes should be prevented from flowing over the slope face by using berms, drainage ditches, swales or other appropriate methods.

If temporary cut slopes experience excessive sloughing or raveling during construction, it may become necessary to modify the cut slopes to maintain safe working conditions. Slopes experiencing problems can be flattened, regraded to add intermediate slope benches, or additional dewatering can be provided if the poor slope performance is related to groundwater seepage.

Foundations

We recommend that the proposed AH&M buildings be supported on shallow spread footings founded on the dense to very dense advance outwash encountered in our borings or on properly compacted structural fill extending down to dense to very dense advance outwash. The following recommendations for the building foundations are based on the subsurface conditions observed in the borings.

Foundation Design

For shallow foundation support, we recommend widths of at least 18 and 24 inches, respectively, for continuous wall and isolated column footings supporting the proposed building. Provided that footings are supported as recommended above, an allowable bearing value of 6,000 psf may be used footings supported on the dense to very dense advance outwash or on CDF placed directly over dense to very dense advance outwash. If CDF is used to support foundations then the zone of CDF should extend beyond the faces of the footing a distance at least equal to one-half the thickness of the CDF.

May 15, 2018 | Page 11 File No. 8030-010-00

Footings supported on structural fill compacted to at least 95 percent MDD may be proportioned for an allowable bearing capacity of 3,000 psf. If structural fill is used to support foundations then the zone of structural fill should extend beyond the faces of the footing a distance at least equal to the thickness of the structural fill.

These allowable bearing pressures apply to the total dead and long-term live loads and may be increased up to one-third for short-term live loads such as wind or seismic forces. All footings near below-grade walls should be embedded to a depth that is at least below a 1H:1V line projected up from the bottom of the closest section of wall, otherwise the below-grade walls need to be designed for lateral loads from the footings.

Exterior footings for structures should be founded at least 18 inches below lowest adjacent finished grade. Interior footings should be founded at least 12 inches below bottom of slab or adjacent finished grade.

Foundation Settlement

We estimate that the post-construction settlement of footings founded on dense to very dense advance outwash or structural fill extending to the dense to very dense outwash, as recommended above, will be between ½ and 1 inch. Differential settlement between comparably loaded column footings or along a 25-foot section of continuous wall footing should be less than ½ inch. We expect most of the footing settlements will occur as loads are applied. Loose or disturbed soils not removed from footing excavations prior to placing concrete will result in additional settlement.

Lateral Resistance

Lateral loads can be resisted by passive resistance on the sides of the footings and by friction on the base of the footings. Passive resistance should be evaluated using an equivalent fluid density of 350 pounds per cubic foot (pcf) where footings are poured neat against native soil or are surrounded by structural fill compacted to at least 95 percent of MDD, as recommended. Resistance to passive pressure should be calculated from the bottom of adjacent floor slabs and paving or below a depth of 1 foot where the adjacent area is unpaved, as appropriate. Frictional resistance can be evaluated using 0.35 for the coefficient of base friction against footings. The above values incorporate a factor of safety of about 1.5.

If soils adjacent to footings are disturbed during construction, the disturbed soils must be recompacted, otherwise the lateral passive resistance value must be reduced.

Construction Considerations

Immediately prior to placing concrete, all debris and loose soils that accumulated in the footing excavations during forming and steel placement must be removed. Debris or loose soils not removed from the footing excavations will result in increased settlement.

If wet weather construction is planned, we recommend that all footing subgrades be protected using a lean concrete mud mat. The mud mat should be placed the same day that the footing subgrade is excavated and approved for foundation support.

We recommend that all completed footing excavations be observed by a representative of our firm prior to placing mud mat, reinforcing steel, and structural concrete. Our representative will confirm that the bearing

May 15, 2018 | Page 12 File No. 8030-010-00

surface has been prepared in a manner consistent with our recommendations and that the subsurface conditions are as expected.

Footing Drains

We recommend that footing drains be installed around the perimeter of the proposed AH&M buildings. The perimeter drains should be installed at the base of the exterior footings, as shown on Figure 6. The perimeter footing drains should be provided with cleanouts and should consist of at least 4-inch-diameter perforated pipe placed on a 3-inch bed of, and surrounded by 6 inches of drainage material enclosed in a non-woven geotextile such as Mirafi 140N (or approved equivalent) to prevent fine soil from migrating into the drain material. We recommend against using flexible tubing for footing drainpipes. The perimeter drains should be sloped to drain by gravity to a suitable discharge point, preferably a storm drain. We recommend that the cleanouts be covered and placed in flush mounted utility boxes. Water collected in roof downspout lines must not be routed to the footing drain lines.

Below-Grade Walls and Retaining Walls

The following recommendations should be used for the design of below-grade walls that are intended to act as retaining walls and for other retaining structures that are used to achieve grade changes.

Design Parameters

Lateral earth pressures for design of below-grade walls and retaining structures should be evaluated using an equivalent fluid density of 35 pcf provided that the walls will not be restrained against rotation when backfill is placed. If the walls will be restrained from rotation, we recommend using an equivalent fluid density of 55 pcf. Walls are assumed to be restrained if top movement during backfilling is less than H/1000, where H is the wall height. These lateral soil pressures assume that the ground surface behind the wall is horizontal. For unrestrained walls with backfill sloping up at 2H:1V, the design lateral earth pressure should be increased to 55 pcf, while restrained walls with a 2H:1V sloping backfill should be designed using an equivalent fluid density of 75 pcf. These lateral soil pressures do not include the effects of surcharges such as floor loads, traffic loads or other surface loading.

Below-grade walls for the building should also include seismic earth pressures. Seismic earth pressures should be determined using a rectangular distribution of 8H in psf.

If vehicles can approach the tops of exterior walls to within one-half the height of the wall, a traffic surcharge should be added to the wall pressure. For car parking areas, the traffic surcharge can be approximated by the equivalent weight of an additional 1 foot of soil backfill (125 psf) behind the wall. For delivery truck parking areas and access driveway areas, the traffic surcharge can be approximated by the equivalent weight of an additional 2 feet (250 psf) of soil backfill behind the wall.

These recommendations are based on the assumption that adequate drainage will be provided behind below-grade walls and retaining structures as discussed below. The values for soil bearing, frictional resistance, and passive resistance presented above for foundation design are applicable to retaining wall design. Walls located in level ground areas should be founded at a depth of 18 inches below the adjacent grade.

May 15, 2018 | Page 13 File No. 8030-010-00

Wall Drainage

Positive drainage should be provided behind below-grade walls and retaining walls by placing a minimum 2-foot-wide zone of free-draining backfill directly behind the wall. The free-draining backfill should meet the recommendations presented on Figure 6 and in the “Structural Fill” section of this report. The free-draining backfill zone should extend from the base of the wall to within 2 feet of the finished ground surface. The top 2 feet of fill should consist of relatively impermeable soil, such as on-site silty outwash soils, underlain by a geotextile separator to prevent infiltration of surface water into the wall drainage zone.

A 4-inch-diameter perforated drainpipe should be installed within the free-draining material at the base of each wall, as shown on Figure 6. We recommend against using flexible tubing for the wall drainpipe. The footing drain recommended above can be incorporated into the bottom of the drainage zone and be used for this purpose.

The pipes should be laid with minimum slopes of one-quarter percent and discharge into the stormwater collection system to convey the water off-site. The pipe installations should include a cleanout riser with cover located at the upper end of each pipe run. The cleanouts could be placed in flush-mounted access boxes. Collected downspout water should be routed to appropriate discharge points in separate pipe systems.

Other Considerations

Exterior retaining systems used to achieve grade transitions or for landscaping, can be constructed using traditional structural systems such as reinforced concrete and concrete masonry unit (CMU) blocks. Alternatively, retaining walls can consist of reinforced soil and block facing structures, which may be an economically reasonable alternative to more traditional retaining wall systems. Non-structural systems such as rockeries may also be used to achieve grade transitions. We can provide additional design recommendations for retaining structures, if requested.

Slab-on-Grade Floor

Subgrade Preparation

We recommend that concrete slabs-on-grade be constructed on a gravel layer to provide uniform support and drainage, and to act as a capillary break. We expect that slab-on-grade floors can be supported on the dense to very dense advance outwash encountered in our borings or on properly compacted structural fill extending down to these materials. Prior to placing the gravel layer, the subgrade should be proof-rolled as described in the “Earthwork” section of this report. If necessary, the subgrade should be recompacted to a firm and unyielding condition.

Design Parameters

A 4-inch-thick capillary break layer of 1-inch minus clean crushed gravel with negligible sand and silt (WSDOT 9-03.1(4)C, Grading No. 67) should be placed to provide uniform support and form a capillary break beneath the slab. For slabs designed as a beam on an elastic foundation, a modulus of subgrade reaction of 100 pounds per cubic inch (pci) may be used for subgrade soils prepared as recommended above.

If water vapor migration through the slabs is objectionable, the capillary break material should be covered with a heavy plastic sheet, such as 10-mil plastic sheeting, to act as a vapor retarder. We recommend that

May 15, 2018 | Page 14 File No. 8030-010-00

the vapor barrier be constructed in accordance with the American Concrete Institute (ACI 302.1R) and that the plastic sheet be placed over the capillary break layer. The contractor should be made responsible for maintaining the integrity of the vapor barrier during construction.

Earthquake Engineering

2015 IBC Seismic Design Information

We recommend the use of the following 2015 IBC parameters for soil profile type, short period spectral response acceleration (SS), 1-second period spectral response acceleration (S1) and seismic coefficients (FA and FV) for the project site.

TABLE 1. 2015 IBC PARAMETERS

2015 IBC Parameter Recommended Value

Soil Profile Type C

Short Period Spectral Response Acceleration, SS (percent g) 125.6

1-Second Period Spectral Response Acceleration, S1 (percent g) 49.1

Seismic Coefficient, FA 1.0

Seismic Coefficient, FV 1.309

Geologic Hazards

Based on our review of the City of Shoreline critical areas code, the site is not located in a geologic hazard area. Based on our review of the borings, the site soils have a low risk of liquefaction, lateral spread, or seismically-induced landslide. Additionally, due to the distance to the closest mapped fault (South Whidbey Fault), the site has a low risk of fault rupture.

Infiltration Considerations

We understand that a storm water infiltration pond is planned at the north end of the Greenwood parking lot. We anticipate that infiltration requirements will be designed in accordance with the Washington State Department of Ecology’s 2012 Stormwater Management Manual for Western Washington (SWMMWW). Initial saturated hydraulic conductivity (Ksat) values were determined for site soils using grain-size analyses as described below. We understand the pond bottom will be at least 8 feet below grade and will have 3H:1V interior side slopes.

Grain-size Analyses

Since the soils have not been glacially consolidated, the initial saturated hydraulic conductivity (Ksat) can be estimated using grain-size analyses per Section 3.3.6 of the SWMMWW.

We completed numerous grain size analyses on selected samples from our explorations at depths of 10 to 15 feet in order to estimate an initial saturated hydraulic conductivity (Ksat) below the proposed pond bottom. The initial saturated hydraulic conductivity values were estimated using the grain size analysis method per Section 3.3.6 of the SWMMWW. The estimated long-term (factored) saturated hydraulic conductivity values for each sample is summarized in Table 2.

May 15, 2018 | Page 15 File No. 8030-010-00

TABLE 2. ESTIMATED LONG-TERM SATURATED HYDRAULIC CONDUCTIVITY

Exploration USCS

Symbol Depth (feet)

D10

(mm) D60

(mm) D90

(mm) ffines (%)

Long-Term Rate (factored) Ksat (in/hr)

B-1 SW-SM 2.5-5 0.08 1.42 12.12 10 2.9

B-2 SP-SM 5.0 0.23 1.44 10.03 5 7.6

B-3 SW-SM 7.5 0.10 1.55 19.94 9 2.6

B-4 SP 7.5 0.22 0.67 1.69 4 9.5

B-4 SW-SM 15.0 0.10 0.76 2.75 9 4.3

B-5 SW-SM 5.0 0.09 0.80 3.77 9 4.0

B-6 SP-SM 2.5 0.08 3.03 17.45 10 2.6

B-7 SP-SM 5.0 0.20 1.30 4.68 6 7.4

B-8 SP-SM 2.5 0.19 2.50 15.79 5 5.6

B-9 SP-SM 5.0 0.08 1.40 11.48 10 3.0

B-10 SM 5.0 0.05 5.10 23.64 13 1.8

B-11 SP-SM 10.0 0.07 2.99 23.86 11 2.0

B-11 SP 15.0 0.27 3.04 15.72 4 8.5

B-12 SP 10.0 0.27 5.09 27.37 2 7.1

B-12 SP-SM 15.0 0.16 0.86 7.08 5 6.0

B-13 SM 10.0 0.02 2.98 20.13 17 1.3

B-13 SP-SM 15.0 0.07 4.22 32.11 10 1.7

B-14 SM 10.0 0.01 1.64 18.56 18 1.2

B-14 SP-SM 15.0 0.18 2.47 12.61 5 5.9

B-15 SP 12.5 0.19 0.99 20.32 4 4.8

B-15 SP-SM 15.0 0.13 0.40 1.00 5 6.2

Notes: mm = millimeter; in/hr = inches per hour

The estimated hydraulic conductivity values (Ksat) in Table 2 are the long-term infiltration rates and include correction factors. The correction factors used for site variability, test method, and degree of influent control to prevent siltation and bio-buildup are 0.33, 0.4, and 0.9, respectively. The combined correction factors result in an overall total correction factor of 0.12 and were applied as outlined in Section 3.3.6 of the SWMMWW.

Pilot Infiltration Tests

If on-site infiltration is planned for the Greenwood parking lot, we recommend that pilot infiltration tests (PITs) be performed at the location of the proposed infiltration pond. It does not appear that a grounding analysis will be required since groundwater was not observed within 40 feet of the proposed pond bottom; the location of the proposed Greenwood pond in relation with the adjacent Boeing Creek detention facility may need to be evaluated. The 2012 SWMMWW requires a cation exchange capacity (CEC) greater than or

May 15, 2018 | Page 16 File No. 8030-010-00

equal to 5 milliequivalent (meq) and an organic content greater than 0.5 percent for bio-treatment of stormwater. The CEC for the on-site soils should be determined prior to final design.

The estimated design infiltration rates presented above are based on grain size distribution and should be used for preliminary planning purposes. Final design of the infiltration pond should be based on in-situ pilot infiltration testing.

Drainage Considerations

We anticipate shallow groundwater seepage may enter excavations depending on the time of year construction takes place, especially in the winter months. However, we expect that this seepage water can be handled by digging interceptor trenches in the excavations and pumping from sumps. The seepage water if not intercepted and removed from the excavations will make it difficult to place and compact structural fill and may destabilize cut slopes.

All paved and landscaped areas should be graded so that surface drainage is directed away from the buildings to appropriate catch basins.

Water collected in roof downspout lines must not be routed to the footing drain lines. Collected downspout water should be routed to appropriate discharge points in separate pipe systems.

Recommended Additional Geotechnical Services

Throughout this report, recommendations are provided where we consider additional geotechnical services to be appropriate. These additional services are summarized below:

■ GeoEngineers should be retained to provide additional recommendations for design and construction of the Greenwood stormwater infiltration facility, including performing pilot infiltration testing, once the final layout and pond bottom elevation is determined.

■ GeoEngineers should be retained to review the project plans and specifications when complete to confirm that our design recommendations have been implemented as intended.

■ During construction, GeoEngineers should evaluate temporary excavations, evaluate the suitability of the foundation, slab and pavement subgrades, observe and test structural backfill including wall backfill, observe and test utility trench backfill, observe installation of subsurface drainage measures, evaluate the Greenwood stormwater pond bottom subgrade, and provide a summary letter of our construction observation services. The purposes of GeoEngineers construction phase services are to confirm that the subsurface conditions are consistent with those observed in the explorations and other reasons described in Appendix D, Report Limitations and Guidelines for Use.

LIMITATIONS

We have prepared this report for use by Shoreline Community College and other members of the design team for use in design of this project.

Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in the field of geotechnical engineering in this area at the time this report was prepared. No warranty or other conditions, express or implied, should be understood.

May 15, 2018 | Page 17 File No. 8030-010-00

Any electronic form, facsimile or hard copy of the original document (email, text, table, and/or figure), if provided, and any attachments are only a copy of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record.

Please refer to Appendix D, Report Limitations and Guidelines for Use for additional information pertaining to use of this report.

REFERENCES

City of Shoreline Environmentally Sensitive Areas Map, 2005.

GeoEngineers Inc. “Master Plan – Stormwater System, Shoreline Community College, Shoreline, Washington.” GEI File No. 8030-006-00, 2009

International Code Council, “International Building Code,” 2015.

Minard, J.P., 1983, “Geologic Map of the Edmonds East and part of the Edmonds West Quadrangles, Washington,” USGS Map MF-1541.

U.S. Geological Survey – National Seismic Hazard Mapping Project, accessed on April 6, 2018 at http://geohazards.usgs.gov/designmaps/us/application.php.

Washington State Department of Ecology, “Stormwater Management in Western Washington, Volume III, Hydrologic Analysis and Flow Control Design/BMPs,” February 2012.

Washington State Department of Transportation, “Standard Specifications for Road, Bridge and Municipal Construction,” 2016.

µ

SITE

Vicinity Map

Figure 1

Allied Health & Manufacturing BuildingsShoreline Community College, Washington

2,000 2,0000

Feet

Data Source: Mapbox Open Street Map, 2018

Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication.

Projection: NAD 1983 UTM Zone 10N

P:\8\

8030

010\

GIS\

MXD\

8030

0100

0_F0

1_VM

.mxd

Date

Expo

rted:

04/1

6/18

by g

lohrm

eyer

SITESITE

D*

D*

D*

D*

TOP SLOPE LINE

TOP SLOPE LINE

LINETOP SLOPE

P

P

P

P

G

G

G

P

B

BB

BB

BB

B

D

D

P

BB

P

P

P

P

P

P

G

G

G

BB

G

G

D

B

B

P

P

P

P

P

D

B

P

P

PP

P

P

P

B

B

B B

B

P

P

P

P

P

BB

BB

CAP

ABANDONED

ABANDONED

W*

W*

W*

*

*

*

*

*

*

*

**

*

*

*

*

*

*

*

*

* 490

390

380

410

400

430

420

450

440

460

470

460

460

460

470

470

464

466

468

464

462

468

464462

462

464

464

466468

474474

474

476

476474

466

466466468468

470472

468466

466

464

462

464

464

466

470

468

468

472472

472

470

470

470

470

480

480

490

490

480

478

480478

492

494

49649649

4

TP-5

TP-4

Bldg 2100

Bldg 2500

Bldg 2300

Bldg 2000

Bldg 1900

Bldg 2200 Bldg 2700

Bldg 2800

Bldg 2600

Bldg 2900

Bldg 3000

Bldg 4000Bldg 1800

B-1

B-10

B-3

B-2

B-4

B-5

B-7

B-6B-8

B-9

Proposed Manufacturing Building

Proposed Allied Health Building

Figure 2

Site Plan - AH&M Buildings

W E

N

S

Legend

P:\8

\803

0010

\CAD

\00\

Geo

Tech

\803

0010

00_F

02-F

04_S

ite P

lans

and

Sec

tion

AA.d

wg

TAB:

F02

Dat

e Ex

porte

d: 0

4/16

/18

- 12:

52 b

y lk

illgo

re

Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing

features discussed in an attached document. GeoEngineers, Inc. cannotguarantee the accuracy and content of electronic files. The master file is storedby GeoEngineers, Inc. and will serve as the official record of this communication.

Data Source: Site Survey by Reid Middleton, Inc., dated September 2010

Projection: WA State Plane, North Zone, NAD83, US Foot

Boring by GeoEngineers, 2018

Test Pit by GeoEngineers, 2009

Feet

080 80

B-1

TP-4

Proposed Building Footprints

Allied Health and Manufacturing BuildingsShoreline Community College, Washington

AutoCAD SHX Text

X

AutoCAD SHX Text

X

AutoCAD SHX Text

X

AutoCAD SHX Text

X

AutoCAD SHX Text

X

AutoCAD SHX Text

X

AutoCAD SHX Text

X

AutoCAD SHX Text

X

AutoCAD SHX Text

X

AutoCAD SHX Text

X

AutoCAD SHX Text

X

AutoCAD SHX Text

X

A'

A

TOP SLOPE LINE

B

B

P

340

330

360

360

350

360350

350360

350

360

370

370

370

370

370

390

380

390

380

380

410400

410

400

430

420

450

440

460

468466

466

464

TP-2

TP-12

Carlyle Hall Rd NW

Greenwood Parking Lot

Boeing Creek Drainage Facility

B'

B

B-13

B-15

B-14

B-11

B-12

Figure 3

Site Plan - Greenwood Infiltration Facility

W E

N

S

Legend

P:\8

\803

0010

\CAD

\00\

Geo

Tech

\803

0010

00_F

02-F

05_S

ite P

lans

and

Sec

tions

A a

nd B

.dw

g TA

B:F0

3 D

ate

Expo

rted:

04/

16/1

8 - 1

5:42

by

lkill

gore

Property Boundary

Boring by GeoEngineers, 2018

Cross Section Location

Feet

060 60

B-11

A'A

Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing

features discussed in an attached document. GeoEngineers, Inc. cannotguarantee the accuracy and content of electronic files. The master file is storedby GeoEngineers, Inc. and will serve as the official record of this communication.

Data Source: Site Survey by Reid Middleton, Inc., dated September 2010

Projection: WA State Plane, North Zone, NAD83, US Foot

Proposed Infiltration Facility Area

TP-2 Test Pit by GeoEngineers, 2009


Elev

atio

n (F

eet)

Elev

atio

n (F

eet)

Distance (Feet)

300

320

340

360

380

400

300

320

340

360

380

400

0 40 80 120 160 200 240 280 320 360 400 440 480 500

A(Southeast)

A'(Northwest)

94

2221

41

39

32

42

31

59

67

78

SM

SP

SP

B-11

(Offs

et 2

0' N

E)

569

17

45

50/6"

58

44

72

82

47

50/5"

SP-SM

SP

SP

SP

SP

SP

B-12

(Offs

et 3

6' S

W)

34020253329

37

32

37

39

50/5"

62

67

SP-SM

SM

SM

SP

SP

SP

SP

SP

B-13

(Offs

et 3

6' N

E)

Proposed Infiltration Facility

SMSM

SM

SMTS

TP-1

2(O

ffset

13'

SW

)

Fill

Outwash

Fill

Outwash

Figure 4

Cross Section A-A' - Greenwood Infiltration Facility

P:\8

\803

0010

\CAD

\00\

Geo

Tech

\803

0010

00_F

02-F

05_S

ite P

lans

and

Sec

tions

A a

nd B

.dw

g TA

B:F0

4 D

ate

Expo

rted:

04/

16/1

8 - 1

5:45

by

lkill

gore

LegendNotes:1. The subsurface conditions shown are based on interpolation between

widely spaced explorations and should be considered approximate; actualsubsurface conditions may vary from those shown.

2. This figure is for informational purposes only. It is intended to assist in theidentification of features discussed in a related document. Data werecompiled from sources as listed in this figure. The data sources do notguarantee these data are accurate or complete. There may have beenupdates to the data since the publication of this figure. This figure is acopy of a master document. The hard copy is stored by GeoEngineers, Inc.and will serve as the official document of record.

Datum: NAVD 88, unless otherwise noted.

SM

20

Boring

Inferred Soil Contact

Soil Classification

Blow Count

Legend

B-11

(Offs

et 2

0' N

E)

Fill

Outwash

Horizontal Scale in Feet

040 40

Vertical Scale in Feet

020 20

Vertical Exaggeration: 2X


Elev

atio

n (F

eet)

Elev

atio

n (F

eet)

Distance (Feet)

300

320

340

360

380

400

300

320

340

360

380

400

0 40 80 120 160 200 240 280 300

B(Southwest)

B'(Northeast)Proposed Infiltration Facility

569

17

45

50/6"

58

44

72

82

47

50/5"

SP-SM

SP

SP

SP

SP

SP

B-12

(Offs

et 0

')

Fill

Outwash

Boeing CreekDrainage Facility

Figure 5

Cross Section B-B' - Greenwood Infiltration Facility

P:\8

\803

0010

\CAD

\00\

Geo

Tech

\803

0010

00_F

02-F

05_S

ite P

lans

and

Sec

tions

A a

nd B

.dw

g TA

B:F0

5 D

ate

Expo

rted:

04/

16/1

8 - 1

5:47

by

lkill

gore

LegendNotes:1. The subsurface conditions shown are based on interpolation between

widely spaced explorations and should be considered approximate; actualsubsurface conditions may vary from those shown.

2. This figure is for informational purposes only. It is intended to assist in theidentification of features discussed in a related document. Data werecompiled from sources as listed in this figure. The data sources do notguarantee these data are accurate or complete. There may have beenupdates to the data since the publication of this figure. This figure is acopy of a master document. The hard copy is stored by GeoEngineers, Inc.and will serve as the official document of record.

Datum: NAVD 88, unless otherwise noted.

SM

20

Boring

Inferred Soil Contact

Soil Classification

Blow Count

Legend

B-11

(Offs

et 2

0' N

E)

Fill

Outwash

Horizontal Scale in Feet

040 40

Vertical Scale in Feet

020 20

Vertical Exaggeration: 2X


Wall Drainage and Backfill

Floor Slab

4" Min.

18" Min.

12" Min. Cover Of Drainage Material

(6" Min. On Sides Of Pipe)

Materials:

Not To Scale

A. WALL DRAINAGE MATERIAL: May consist of washed 38" to No. 8 pea gravel or "Gravel Backfill for Drains" perWSDOT Standard Specification 9-03.12(4), surrounded with a non-woven geotextile such as Mirafi 140N (or approvedequivalent).

B. RETAINED SOIL: Should consist of structural fill, either on-site soil or imported. The backfill should be compactedin loose lifts not exceeding 6 inches within 5' of the wall. Wall backfill supporting building floor slabs should consist ofimported sand and gravel such as WSDOT Standard Specification 9-03.14 compacted to at least 95 percent ASTMD1557. Backfill not supporting building floor slabs, sidewalks, or pavement should be compacted to 90 to 92 percentof the maximum dry density, per ASTM D1557. Backfill supporting sidewalks or pavement areas should be compactedto at least 95 percent in the upper two feet. Only hand-operated equipment should be used for compaction within 5feet of the walls and no heavy equipment should be allowed within 5 feet of the wall.

C. CAPILLARY BREAK: Should consist of at least 4 inches of clean crushed gravel with a maximum size of 1 inchand negligible sand or fines, per WSDOT 9-03.1(4)C, Grading No. 67.

D. PERFORATED DRAIN PIPE: Should consist of a minimum 4-inch diameter perforated heavy-wall solid pipe(SDR-35 PVC) or rigid corrugated polyethylene pipe (ADS N-12) or equivalent. Drain pipes should be placed with 0.25percent minimum slopes and discharge to the storm water collection system.

Notes:1. Thickness/location of permanent wall and slab on grade, and perimeter

foundation shown here to depict intent of wall drainage design. Actual

thickness/location of these structural elements will vary.

Nonwoven Geotextile

TemporaryExcavation Slope

Pavement Or 24"Low Permeability Soil

Retained Soil

Sloped To Drain AwayFrom Structure

4" DiameterPerforated Drain Pipe

Capillary Break

Vapor Retarder

Damp Proofing/Water Proofing

Wall Drainage Material

Exterior Wall

Nonwoven Geotextile

Figure 6

P:\8

\803

0010

\CAD

\00\

Geo

Tech

\803

0010

00_F

05_W

all D

rain

age

and

Back

fill.d

wg

TAB:

F05

Dat

e Ex

porte

d: 0

4/16

/18

- 12:

59 b

y lk

illgo

re


Compaction Criteriafor Trench Backfill

95

9090

95

90

Pipe

Varies

Varies(See Note 1)

2 Feet

Varies

(Modified Proctor)

Pipe Bedding

Trench Backfill

Base Course

Concrete or Asphalt Pavement

Maximum Dry Density, by Test Method ASTM D1557Recommended Compaction as a Percentage of

Legend

95

Not To Scale

Notes:1. All backfill under building areas should be compacted to at

least 95 percent per ASTM D1557.

Non-structuralAreas

Hardscape OrPavement

Areas

Ground Surface

P:\8

\803

0010

\CAD

\00\

Geo

Tech

\803

0010

00_F

06_C

ompa

ctio

n Cr

iteria

for T

renc

h Ba

ckfil

l.dw

g TA

B:3

Dat

e Ex

porte

d: 0

4/16

/18

- 13:

00 b

y lk

illgo

re

Figure 7


APPENDIX A Field Explorations

May 15, 2018 | Page A-1 File No. 8030-010-00

APPENDIX A FIELD EXPLORATIONS

Subsurface soil and groundwater conditions at the project site were explored by drilling fifteen borings to depths of 21.5 to 51.5 feet. Borings B-1 through B-10 were drilled for the AH&M on March 19 and March 20, 2018 by Geologic Drill, Inc., using truck-mounted, continuous flight, hollow-stem auger drilling equipment. Borings B-11 through B-15 were drilled for the proposed Greenwood stormwater facility on March 8, 2018 by Holocene, Inc., using truck-mounted, continuous flight, hollow-stem auger drilling equipment. Locations of the explorations were determined in the field by measuring distances from existing site features. The locations of the explorations are shown on Figures 2 and 3.

The borings were continuously monitored by a geotechnical engineer from our firm who evaluated and classified the soils encountered, obtained representative soil samples, observed groundwater conditions, and prepared a detailed log of each exploration. Relatively undisturbed samples were obtained from the borings at selected depths using a 1½-inch inside-diameter split-barrel sampler. The sampler was driven into the soil a distance of 18 inches or other specified distance using a cathead operated 140-pound hammer free-falling a vertical distance of 30 inches. The number of hammer blows needed to drive the sampler the final 12 inches or other indicated distance is recorded on the boring logs.

The soils encountered were visually classified in the field in general accordance with the Unified Soil Classification System (USCS) and American Society for Testing and Materials (ASTM) D 2488, which is summarized in Figure A-1. Boring logs are shown in Figures A-2 through A-16. These logs are based on our interpretation of the field and laboratory data and indicate the various soils encountered. They also indicate the approximate depths at which the soils or their characteristics change; although the change may be gradual. If the change occurred between sampling locations, the depth was inferred.

Monitoring Well

A monitoring well was installed in boring B-12 to allow measurement of groundwater levels following drilling. The well was installed in accordance with the Department of Ecology requirements. The monitoring wells were constructed using 2-inch-diameter polyvinyl chloride (PVC) casing and well screen. The depth to which the casing was installed was selected based on our understanding of subsurface soil and groundwater conditions in the borings.

The lower portion of the casing assembly included a machine-cut well screen that was slotted with 0.020-inch-wide slots to allow entry of water into the monitoring well. Colorado silica sand (10/20) was placed in the borehole annulus surrounding the well screen. A bentonite seal was placed above the well screen to form a surface seal. The monitoring well was protected by installing a flush-grade steel monument set in concrete. Details of the monitoring well installation is presented on the exploration log in this Appendix.

We measured groundwater levels in the well on March 8 and March 20, 2018. No groundwater was measured on either day.

Measured groundwater level in exploration,well, or piezometer

Measured free product in well or piezometer

Distinct contact between soil strata

Approximate contact between soil strata

Contact between geologic units

SYMBOLS TYPICALDESCRIPTIONS

GW

GP

SW

SP

SM

FINEGRAINED

SOILS

SILTS ANDCLAYS

NOTE: Multiple symbols are used to indicate borderline or dual soil classifications

MORE THAN 50%RETAINED ONNO. 200 SIEVE

MORE THAN 50%PASSING

NO. 200 SIEVE

GRAVELAND

GRAVELLYSOILS

SC

LIQUID LIMITLESS THAN 50

(APPRECIABLE AMOUNTOF FINES)

(APPRECIABLE AMOUNTOF FINES)

COARSEGRAINED

SOILS

MAJOR DIVISIONSGRAPH LETTER

GM

GC

ML

CL

OL

SILTS ANDCLAYS

SANDS WITHFINES

SANDAND

SANDYSOILS

MH

CH

OH

PT

(LITTLE OR NO FINES)

CLEAN SANDS

GRAVELS WITHFINES

CLEAN GRAVELS

(LITTLE OR NO FINES)

WELL-GRADED GRAVELS, GRAVEL -SAND MIXTURES

CLAYEY GRAVELS, GRAVEL - SAND -CLAY MIXTURES

WELL-GRADED SANDS, GRAVELLYSANDS

POORLY-GRADED SANDS, GRAVELLYSAND

SILTY SANDS, SAND - SILT MIXTURES

CLAYEY SANDS, SAND - CLAYMIXTURES

INORGANIC SILTS, ROCK FLOUR,CLAYEY SILTS WITH SLIGHTPLASTICITY

INORGANIC CLAYS OF LOW TOMEDIUM PLASTICITY, GRAVELLYCLAYS, SANDY CLAYS, SILTY CLAYS,LEAN CLAYS

ORGANIC SILTS AND ORGANIC SILTYCLAYS OF LOW PLASTICITY

INORGANIC SILTS, MICACEOUS ORDIATOMACEOUS SILTY SOILS

INORGANIC CLAYS OF HIGHPLASTICITY

ORGANIC CLAYS AND SILTS OFMEDIUM TO HIGH PLASTICITY

PEAT, HUMUS, SWAMP SOILS WITHHIGH ORGANIC CONTENTSHIGHLY ORGANIC SOILS

SOIL CLASSIFICATION CHART

MORE THAN 50%OF COARSE

FRACTION RETAINEDON NO. 4 SIEVE

MORE THAN 50%OF COARSE

FRACTION PASSINGON NO. 4 SIEVE

SILTY GRAVELS, GRAVEL - SAND -SILT MIXTURES

POORLY-GRADED GRAVELS,GRAVEL - SAND MIXTURES

LIQUID LIMIT GREATERTHAN 50

Continuous Coring

Bulk or grab

Direct-Push

Piston

Shelby tube

Standard Penetration Test (SPT)

2.4-inch I.D. split barrel

Contact between soil of the same geologicunit

Material Description Contact

Graphic Log Contact

NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurface conditions.Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made; they are not warranted to berepresentative of subsurface conditions at other locations or times.

Groundwater Contact

Blowcount is recorded for driven samplers as the number ofblows required to advance sampler 12 inches (or distance noted).See exploration log for hammer weight and drop.

"P" indicates sampler pushed using the weight of the drill rig.

"WOH" indicates sampler pushed using the weight of thehammer.

Key to Exploration Logs

Figure A-1

Sampler Symbol Descriptions

ADDITIONAL MATERIAL SYMBOLS

NSSSMSHS

No Visible SheenSlight SheenModerate SheenHeavy Sheen

Sheen Classification

SYMBOLS

Asphalt Concrete

Cement Concrete

Crushed Rock/Quarry Spalls

Topsoil

GRAPH LETTER

AC

CC

SOD Sod/Forest Duff

CR

DESCRIPTIONSTYPICAL

TS

Laboratory / Field Tests%F%GALCACPCSDDDSHAMCMDMohsOCPMPIPPSATXUCVS

Percent finesPercent gravelAtterberg limitsChemical analysisLaboratory compaction testConsolidation testDry densityDirect shearHydrometer analysisMoisture contentMoisture content and dry densityMohs hardness scaleOrganic contentPermeability or hydraulic conductivityPlasticity indexPocket penetrometerSieve analysisTriaxial compressionUnconfined compressionVane shear

tnash

Typewritten Text

Rev 06/2017

107

7

7

2 inches crushed gravel pathBrown fine to coarse sand with silt and gravel (loose,

moist) (fill)

Brownish gray fine to coarse sand with gravel, silt andcobbles (medium dense, moist)

Brownish gray fine to medium sand (dense, moist)(outwash)

Becomes very dense

1SA

2

3MC

4

5MC

6

9

6

13

13

14

9

6

16

36

36

50

50/6"

CR

SW-SM

SW-SM

SP

Notes:

3/20/2018 3/20/2018 21.5PEBEFT Geologic Drill Exploration, Inc. Hollow-stem Auger

Mini-Track RigDrillingEquipment

Rope & Cathead140 (lbs) / 30 (in) Drop

WA State Plane NorthNAD83 (feet)

1264788277101

482NAVD88

Easting (X)Northing (Y)

Surface Elevation (ft)Vertical Datum

DrilledStart End Total

Depth (ft)Logged ByChecked By

HammerData

SystemDatum

Driller DrillingMethod

Groundwater not observed at time of exploration

Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Google Earth. Vertical approximated based on Google Earth.

Sheet 1 of 1Project Number:

Project Location:

Project:

Shoreline Community College, Washington

8030-010-00

Log of Boring B-1Allied Health and Manufacturing Buildings

Figure A-2

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

480

475

470

465

5

13

4

4

5

10

Orangish brown silty fine to medium sand with gravel(medium dense, moist) (fill)

Brownish gray fine to coarse sand with silt and gravel(dense, moist) (outwash)

Dark gray fine to medium sand (dense, moist)

Grades to fine sand

Layers of light brown fine sand

Gray fine to medium sand with silt (very dense, moist)

1MC

2SA

3MC

4MC

5

6MC

11

16

11

14

22

41

38

33

36

55

SM

SP-SM

SP

SP-SM

Notes:





1264768277184

482NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-3

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

480

475

470

465

9

16

7

6

6

11

12

Lots of gravel/cobbles; moved hole 2 feet east

4 inches wood chipsDark to light brown silty fine to medium sand with

gravel and organic material (very loose, moist) (fill)

Dark gray brown fine to coarse sand with silt and gravel(loose, moist)

Gray fine to medium sand with silt, gravel and cobbles,some oxidation (dense, moist) (outwash)

Gray fine to medium sand with silt, gravel and cobbles(very dense, moist)

Gray fine to coarse sand with silt, gravel, cobbles,mottled with dark brown sand (very dense, moist)

Gray silty fine to medium sand with gravel (very dense,moist)

Gray fine to medium sand (dense, moist)

Brownish gray silty fine to medium sand and gravel(very dense, moist)

1MC

2MC

3SA

4MC

5

6MC

7

8MC

8

6

13

12

9

14

13

16

3

5

42

53

76

60

41

74

WD

SM

SP-SM

SW-SM

SP-SM

SP-SM

SM

SP

SM

Notes:





1264666277143

484NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-4

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

25

30

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

480

475

470

465

460

455

4

9

17

13

6

7

6

6

11

Pipe at 5 feet below the ground surface; movedboring

4 inches wood chipsBrown silty fine to medium sand with gravel (loose,

moist) (fill)

Organic material

Brown fine to medium sand (loose, moist) (weatheredoutwash)

Grades to gray (medium dense, moist) (outwash)

Gray brown fine to coarse sand with silt (very dense,moist)

Gray fine to medium sand (very dense, moist)

Grades to fine to coarse sand

Gray brown fine to medium sand with silt, gravel andcobbles (very dense, moist)

Light brownish gray silty fine to medium sand withgravel (very dense, moist)

1MC

2MC

3SA

4MC

5SA

6MC

7

8MC

4

8

15

13

18

17

18

8

22

9

33

55

52

69

93

WD

SM

SP

SP-SM

SP

SP-SM

SM

Notes:





1264671277215

484NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-5

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

25

30

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

480

475

470

465

460

455

9

5

6

8

7

6 inches roots and topsoilBrown fine to medium sand (medium dense, moist)

(outwash)

Brown fine to coarse sand with silt and occasionalgravel (dense, moist)

Brown fine to medium sand with silt (medium dense,moist)

Grades to with occasional gravel (very dense, moist)

Light gray fine to coarse sand with gravel and silt (verydense, moist)

1 inch lens of black organic matter

Light brownish gray fine to medium sand with silt andgravel (very dense, moist)

1MC

2SA

3MC

4MC

5

6

10

16

16

13

10

11

25

39

28

50

75

51

TS

SP

SW-SM

SP-SM

SP-SM

SP-SM

Notes:





1264677277264

479NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-6

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

475

470

465

460

106

5

6

5

2 inches asphalt concrete pavementBrown fine to medium sand with silt and gravel (dense,

moist) (outwash)

Grades to fine to coarse sand (very dense)

Grades to fine to medium sand

1SA

2MC

3MC

4MC

5

6

10

13

10

9

18

18

42

42

83

67

56

66

AC

SP-SM

Notes:


XL Truck RigDrillingEquipment



1264691277449

469NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-7

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

465

460

455

450

6

6

4

5

6

First 6 inches bouncing on rock

2 inches asphalt concrete pavementBrownish orange fine to medium sand with silt and

gravel (medium dense, moist) (fill)

Brownish gray fine to medium sand with silt andoccasional gravel (dense, moist) (outwash)

Brown fine to medium sand with silt and gravel (verydense, moist)

Brown fine to coarse sand with silt and gravel (verydense, moist)

Brown fine to coarse sand with gravel (dense, moist)


1MC

2SA

3MC

4MC

5

6

6

11

15

14

18

17

44

51

88

43

65

AC

SP-SM

SP-SM

SP-SM

SP-SM

SP

SP-SM

Notes:





1264582277380

471NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-8

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

470

465

460

455

450

55

4

8

10

2 inches asphalt concrete pavementBrown fine to coarse sand with silt and gravel (medium

dense, moist) (outwash/fill?)

Becomes dense

Brown silty fine to medium sand with gravel (gravelinterbedded layers) (very dense, moist) (outwash)

Becomes very dense

Brown fine to coarse sand with silt and gravel (verydense, moist)

Brown fine to medium sand with gravel (very dense,moist)

1SA

2MC

3MC

4MC

5

6

10

10

17

18

12

14

39

50

64

56

70

AC

SP-SM

SM

SP-SM

SP

Notes:





1264621277454

467NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-9

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

465

460

455

450

10

7

7

6

5

1½ inches asphalt concrete pavementBrown fine to medium sand with silt and occasional

gravel, trace organic matter (medium dense, moist)(outwash/fill?)

Brown fine to medium sand with silt and gravel (dense,moist) (outwash)

Brown fine to medium sand with gravel (very dense,moist)


Becomes dense


1MC

2SA

3MC

4MC

5

6

7

12

9

16

15

18

18

34

55

51

52

48

50/6"

AC

SP-SM

SP-SM

SP

SP-SM

SP-SM

Notes:





1264645277517

464NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-10

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

460

455

450

445

13

6

5

6

Driller noted drilling through a cobble beforecollecting sample

No recoveryDriller commented on gravel and cobbles

1½ inches asphalt concrete pavementBrown fine to medium sand with silt and gravel (dense,

moist) (outwash?)

Brown silty fine to medium sand with gravel (dense,moist)

Brown fine to coarse sand with silt and gravel

1MC

2SA

3

4MC

5

6

10

12

0

14

13

18

38

45

50/3"

50

50

56

AC

SP-SM

SM

SP-SM

Notes:





1264537277446

468NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-11

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

465

460

455

450

11

4

15

5

3

10

4 inches crushed gravel surfacingBrown fine to medium sand with occasional gravel

(loose, moist) (fill)

Trace organic matter

With gravel and cobbles (medium dense, moist)

Brown fine to coarse sand with silt and gravel (mediumdense, moist) (outwash)

Brown fine to coarse sand with gravel (dense, moist)

Grades to fine to medium sand with occasional gravel

1

2MC

3

4SA

5SA

6

7MC

8

15

10

18

12

18

18

18

18

9

4

22

21

41

39

32

42

CR

SM

SP-SM

SP

Notes:

51.5PEBEFT Holocene Drilling, Inc. Hollow-stem Auger

Truck-mounted RigDrillingEquipment

Automatic140 (lbs) / 30 (in) Drop


1264830277959

359NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-12

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

25

30

35

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

355

350

345

340

335

330

325

6

6

Light brown fine to medium sand (very dense, moist)

9MC

10

11MC

12

8

18

18

18

31

59

67

78

SP


Project Location:

Project:


8030-010-00

Log of Boring B-11 (continued)Allied Health and Manufacturing Buildings

Figure A-12

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

35

40

45

50

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

320

315

310

4 inches crushed gravel surfacingBrown fine to coarse sand with silt and gravel

(loose, moist) (fill)

Brown fine to coarse sand with gravel and cobbles(loose, moist) (weathered outwash)

Becomes medium dense

Brown gray fine to coarse sand with silt and gravel(dense, moist) (outwash)

Brown fine to medium sand with occasional gravel(very dense, moist)

Light brown fine sand (very dense, moist)

Becomes dense

1MC

2

3MC

4SA

5SA

6

7MC

8

2

1

9

9

15

3

18

15

5

6

9

17

45

50/6"

58

44

CR

SP-SM

SP

SP-SM

SP

SP

Concrete seal

Bentonite chips

2-inch Schedule 40PVC well casing

210

7

3

7

5

2

5

StartDrilled 3/8/2018

HammerData

Date MeasuredHorizontalDatum

Vertical Datum


DrillingEquipment

Top of CasingElevation (ft)

Elevation (ft)Groundwater Depth to

Water (ft)

Notes:

Surface Elevation (ft)

Logged By

Truck-mounted Rig

360NAVD88

1264935277804

WA State Plane NorthNAD83 (feet) 3/20/18 Dry N/A

DOE Well I.D.: BKC-372A 2 (in) well was installed on 3/8/2018 to a depth of 51.5(ft).

51.5 DrillingMethod3/8/2018

EndChecked By DrillerTotal

Depth (ft)


PEBEFT

Holocene Drilling, Inc. Hollow-stem Auger


Steel surfacemonument

Elev

atio

n (f

eet)

355

350

345

340

335

330

325

Dep

th (f

eet)

0

5

10

15

20

25

30

35

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Wat

er L

evel

Inte

rval

Rec

over

ed (i

n)

Blo

ws/

foot

Col

lect

ed S

ampl

e

Gra

phic

Log

Gro

upC

lass

ifica

tion

WELL LOG

Moi

stur

eC

onte

nt (%

)

Fine

sC

onte

nt (%

)


Project Location:

Project:


8030-010-00

Log of Boring (with Monitoring Well) B-12Allied Health and Manufacturing Buildings

Figure A-13

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_WEL

L_%

F

Becomes very dense

Brown fine sand (dense to very dense, moist)

9MC

10

11MC

12

15

16

14

17

72

82

47

50/5"

SP

Bentonite chips

2-inch Schedule 40PVC well casing

Colorado silica sandbackfill

2-inch Schedule 40PVC screen,0.010-inch slotwidth

38

40

50

51.5

5

5

Elev

atio

n (f

eet)

320

315

310

Dep

th (f

eet)

35

40

45

50

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Wat

er L

evel

Inte

rval

Rec

over

ed (i

n)

Blo

ws/

foot

Col

lect

ed S

ampl

e

Gra

phic

Log

Gro

upC

lass

ifica

tion

WELL LOG

Moi

stur

eC

onte

nt (%

)

Fine

sC

onte

nt (%

)


Project Location:

Project:


8030-010-00

Log of Boring (with Monitoring Well) B-12 (continued)Allied Health and Manufacturing Buildings

Figure A-13

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_WEL

L_%

F

17

10

8

8

5

7

4 inches crushed gravel surfacingBrown fine to medium sand with silt and gravel (very

loose, moist) (fill)

Brown and gray silty fine to coarse sand with gravel andcobbles (medium dense, moist)

Brown fine to medium sand with silt and gravel(medium dense to dense, moist) (outwash)

Brown fine to medium sand (dense, moist)

Light brown gray fine to medium sand (dense, moist)

1

2MC

3

4SA

5

6SA

7

8MC

9

3

18

18

18

12

12

16

16

3

40

20

25

33

29

37

32

37

CR

SP-SM

SM

SP-SM

SP

SP

Notes:

3/8/2018 3/8/2018 51.5PEBEFT Holocene Drilling, Inc. Hollow-stem Auger




1265133277739

364NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-14

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

25

30

35

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

360

355

350

345

340

335

330

6

7

Light brown gray fine to medium sand with gravellenses (dense, moist)

Brown gray fine to medium sand (very dense, moist)

10MC

11

12MC

13

14

15

15

18

39

50/5"

62

67

SP

SP


Project Location:

Project:


8030-010-00

Log of Boring B-13 (continued)Allied Health and Manufacturing Buildings

Figure A-14

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

35

40

45

50

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

325

320

315

18

5

13

19

10

4

7

4 inches grassBrown fine to medium sand with silt (medium dense,

moist) (fill)

Brown silty fine to medium sand with gravel (dense,moist)

Brown sandy silt with gravel, trace organic matter (hard,moist)

Brown silty fine to coarse sand with gravel (dense,moist)

Becomes medium dense

Brown reddish fine to medium sand with gravel(medium dense, moist) (weathered outwash)

Brown fine to coarse sand with silt and gravel (mediumdense, moist)

Brown fine to medium sand with gravel and gravellayers (dense, wet) (outwash)

Brown gray fine to medium sand with occasional gravel(dense, moist)

1MC

2

3MC

4SA

5

6SA

7

8MC

11

16

16

16

8

15

18

22

36

33

33

17

22

43

43

SOD

SP-SM

SM

ML

SM

SP

SP-SM

SP

SP

Notes:





1264890277885

359NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-15

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

25

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

355

350

345

340

335

4

5

12

11

4

5

9

5

4 inches grassBrown silty fine to coarse sand with gravel (medium

dense, moist) (fill)

Brown and gray silty fine to medium sand with gravel(medium dense, moist)

Brown fine to medium sand with silt, gravel (dense,moist) (outwash)

Brown fine to medium sand with gravel (medium dense,moist)

Brown gray fine to medium sand with silt and gravel(dense, moist)

Light gray brown fine sand (medium dense, moist)

Grades to dense

1MC

2

3MC

4

5SA

6SA

7MC

8

9MC

8

18

14

5

12

15

18

17

21

21

33

24

31

22

47

48

SOD

SM

SM

SP-SM

SP

SP-SM

SP

Notes:





1265040277767

362NAVD88





HammerData

SystemDatum





Project Location:

Project:


8030-010-00


Figure A-16

Dat

e:5

/15

/18

Pat

h:W

:\PR

OJE

CTS

\8\8

03

00

10

\GIN

T\8

03

00

10

00

.GPJ

DB

Libr

ary/

Libr

ary:

GEO

ENG

INEE

RS

_DF_

STD

_US

_JU

NE_

20

17

.GLB

/GEI

8_G

EOTE

CH

_STA

ND

ARD

_%F_

NO

_GW

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

FIELD DATA

MATERIALDESCRIPTION

Sam

ple

Nam

eTe

stin

g

Rec

over

ed (i

n)

Inte

rval

Blo

ws/

foot

Col

lect

ed S

ampl

e

Dep

th (f

eet)

0

5

10

15

20

25

30

Gra

phic

Log

Gro

upC

lass

ifica

tion

Elev

atio

n (f

eet)

360

355

350

345

340

335

APPENDIX B Laboratory Testing

May 15, 2018 | Page B-1 File No. 8030-010-00

APPENDIX B LABORATORY TESTING

Laboratory Testing

All soil samples obtained from the explorations were visually classified in the field and/or in our laboratory using a system based on the USCS and ASTM classification methods. ASTM test method D 2488 was used to visually classify the soil samples, while ASTM D 2487 was used to classify the soils based on laboratory tests results. These classification procedures are incorporated in the exploration logs shown in Figures A-2 through A-16.

Moisture Content Determinations

Moisture contents were determined in general accordance with ASTM D 2216 for numerous samples obtained from the borings. The results of these tests are presented on the boring logs at the respective sample depth in Appendix A.

Percent Passing U.S. No. 200 Sieve

Selected samples were “washed” through the U.S. No. 200 mesh sieve to determine the relative percentage of coarse- and fine-grained particles in the soil. The percent passing value represents the percentage by weight of the sample finer than the U.S. No. 200 sieve. These tests were conducted in general accordance with ASTM D 1140, and the results are shown on the exploration logs at the representative sample depths.

Sieve Analyses

Selected samples were testing to determine their grain size distribution, as well as determine the percentage of coarse- and fine-grained particles in the soil. These tests were conducted in general accordance with ASTM C 136, and the results are shown on Figures B-1 through B-6.

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.11101001000

PER

CEN

T PA

SSIN

G B

Y W

EIG

HT

GRAIN SIZE IN MILLIMETERS

U.S. STANDARD SIEVE SIZE

SANDSILT OR CLAYCOBBLES

GRAVEL

COARSE MEDIUM FINECOARSE FINE

Boring NumberDepth(feet) Soil Description

B-1B-2B-3B-4

2.5/55

7.57.5

Fine to coarse sand with silt and gravel (SW-SM)Fine to coarse sand with silt and gravel (SP-SM)Fine to coarse sand with silt and gravel (SW-SM)

Fine to medium sand (SP)

SymbolMoisture

(%)7466

3/8”3” 1.5” #4 #10 #20 #40 #60 #1003/4”

Figure B-1

Sieve Analysis Results

Allied Health &

Manufacturing Buildings

Shoreline Comm

unity College, Washington

8030-010-00 Date Exported: 04/02/18

Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they wereperformed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes.

The grain size analysis results were obtained in general accordance with ASTM D 6913.

#200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.11101001000

PER

CEN

T PA

SSIN

G B

Y W

EIG

HT




GRAVEL



B-4B-5B-6B-7

155

2.55

Fine to coarse sand with silt (SW-SM)Fine to coarse sand with silt and occasional gravel (SW-SM)

Fine to medium sand with silt and gravel (SP-SM)Fine to medium sand with silt and occasional gravel (SP-SM)

SymbolMoisture

(%)6664

3/8”3” 1.5” #4 #10 #20 #40 #60 #1003/4”

Figure B-2


Allied Health &


Shoreline Comm


8030-010-00 Date Exported: 04/02/18



#200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.11101001000

PER

CEN

T PA

SSIN

G B

Y W

EIG

HT




GRAVEL



B-8B-9

B-10B-11

2.555

10

Fine to coarse sand with silt and gravel (SP-SM)Fine to medium sand with silt and gravel (SP-SM)

Silty fine to medium sand with gravel (SM)Fine to coarse sand with silt and gravel (SP-SM)

SymbolMoisture

(%)5755

3/8”3” 1.5” #4 #10 #20 #40 #60 #1003/4”

Figure B-3


Allied Health &


Shoreline Comm


8030-010-00 Date Exported: 04/02/18



#200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.11101001000

PER

CEN

T PA

SSIN

G B

Y W

EIG

HT




GRAVEL



B-11B-12B-12B-13

15101510

Fine to coarse sand with gravel (SP)Fine to coarse sand with gravel (SP)

Fine to coarse sand with silt and gravel (SP-SM)Silty fine to coarse sand with gravel (SM)

SymbolMoisture

(%)3378

3/8”3” 1.5” #4 #10 #20 #40 #60 #1003/4”

Figure B-4


Allied Health &


Shoreline Comm


8030-010-00 Date Exported: 04/02/18



#200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.11101001000

PER

CEN

T PA

SSIN

G B

Y W

EIG

HT




GRAVEL



B-13B-14B-14B-15

151015

12.5

Fine to medium sand with silt and gravel (SP-SM)Silty Fine to coarse sand with gravel (SM)

Fine to coarse sand with silt and gravel (SP-SM)Fine to medium sand with gravel (SP)

SymbolMoisture

(%)5

1044

3/8”3” 1.5” #4 #10 #20 #40 #60 #1003/4”

Figure B-5


Allied Health &


Shoreline Comm


8030-010-00 Date Exported: 04/02/18



#200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.11101001000

PER

CEN

T PA

SSIN

G B

Y W

EIG

HT




GRAVEL



B-15 15 Fine to medium sand with silt (SP-SM)

SymbolMoisture

(%)5

3/8”3” 1.5” #4 #10 #20 #40 #60 #1003/4”

Figure B-6


Allied Health &


Shoreline Comm


8030-010-00 Date Exported: 04/02/18



#200

APPENDIX C Previous Exploration

May 15, 2018 | Page C-1 File No. 8030-010-00

APPENDIX C PREVIOUS EXPLORATIONS

Appendix C presents the logs of previous explorations by Geoengineers in the project area including four test pits (TP-2, TP-4, TP-5, TP-12) completed in 2009 for the Shoreline Community College Master Plan Stormwater System project.

1

2

3

4

5

6

CR

SM

TS

SM

SP-SM

4 inches crushed rockBrown silty fine to medium sand with gravel (medium dense, moist) (fill)

Old topsoil

Orange silty fine sand (medium dense to dense, moist)

Gray/brown fine to medium sand with silt (dense, moist) (advance outwash)

No groundwater seepage observedNo caving observed

P=1 to 2 inches

P=2 to 3 inches

P=8 to 9 inches

P=2 to 3 inches

SA, %F=76

Notes: See Figure A-1 for explanation of symbols.The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 0.5 foot.Elevation was estimated from base survey map.

Eve

rett:

Dat

e:10

/12/

09 P

ath:

P:\8

\803

0006

\00\

GIN

T\80

3000

600.

GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GE

OE

NG

INE

ER

S8.

GD

T/G

EI8

_TE

STP

IT_1

P_G

EO

TEC

Sheet 1 of 1

Project:Project Location:Project Number: 8030-006-00

Master Plan - Stormwater SystemShoreline Community College

Figure A-3

Log of Test Pit TP-2

Date Excavated:Equipment: 10Total Depth (ft)

9/9/2009 BPDLogged By:Case Rubber Tire Backhoe

Test

ing

Sam

ple

Sam

ple

Nam

eTe

stin

g

Dep

th (f

eet)

1

2

3

4

5

6

7

8

9

10

SAMPLE

Gra

phic

Log

Gro

upC

lass

ifica

tion MATERIAL

DESCRIPTION

Enc

ount

ered

Wat

er

Ele

vatio

n (fe

et)

373

372

371

370

369

368

367

366

365

364

REMARKS

Moi

stur

eC

onte

nt, %

1

2

3

4

5

TS

SM

SP-SM

SP

2 inches topsoilBrown/gray silty fine to medium sand with gravel (very dense, moist)

(glacial till)

Brown fine to medium sand with silt (very dense, moist) (advance outwash)

Brown and black fine to medium sand (very dense, moist)


P=<1-inch

P=<1-inch

SA, %F=33


Eve

rett:

Dat

e:10

/12/

09 P

ath:

P:\8

\803

0006

\00\

GIN

T\80

3000

600.

GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GE

OE

NG

INE

ER

S8.

GD

T/G

EI8

_TE

STP

IT_1

P_G

EO

TEC

Sheet 1 of 1



Figure A-5


Date Excavated:Equipment: 10Total Depth (ft)


Test

ing

Sam

ple

Sam

ple

Nam

eTe

stin

g

Dep

th (f

eet)

1

2

3

4

5

6

7

8

9

10

SAMPLE

Gra

phic

Log

Gro

upC

lass

ifica

tion MATERIAL

DESCRIPTION

Enc

ount

ered

Wat

er

Ele

vatio

n (fe

et)

487

486

485

484

483

482

481

480

479

478

REMARKS

Moi

stur

eC

onte

nt, %

TS

SM

SM

2 inches topsoilGray/brown silty fine sand with gravel (medium

dense to dense, moist) (fill)

Asphalt pieces

Orange/brown silty fine sand with gravel (verydense, moist) (glacial till)


1

2

3

4

P=2 to 3 inches

P=2 to 3 inches

TotalDepth (ft)9/9/2009 9/9/2009

HammerData

SystemDatum

Start EndChecked ByLogged By

DCODrilled

Notes:

BPD


Driller

GroundwaterDepth toWater (ft)Date Measured Elevation (ft)

LatitudeLongitude

Case Rubber Tire Backhoe

N/A

GeoEngineers, Inc. DrillingMethod8

477.0 DrillingEquipment


FIELD DATAB

low

s/fo

ot

Dep

th (f

eet)

0

5

Rec

over

ed (i

n)

Inte

rval

Col

lect

ed S

ampl

e

Ele

vatio

n (fe

et)

475

470

Gra

phic

Log

Gro

upC

lass

ifica

tion MATERIAL

DESCRIPTIONS

ampl

e N

ame

Test

ing

Wat

er L

evel

Sheet 1 of 1



Figure A-6


Eve

rett:

Dat

e:10

/13/

09 P

ath:

P:\8

\803

0006

\00\

GIN

T\80

3000

600.

GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GE

OE

NG

INE

ER

S8.

GD

T/G

EI8

_GE

OTE

CH

_STA

ND

AR

D

REMARKS

Moi

stur

eC

onte

nt, %

Dry

Den

sity

,(p

cf)

1

2

3

4

5

6

CR

SM

SM

SM

TS

SM

4 inches crushed rockOrange/brown silty fine sand (medium dense, moist) (fill)

Gray silty fine sand with gravel (medium dense to dense, moist)

Blue/gray silty fine to medium sand with gravel (medium dense to dense,moist)

Old topsoil and roots

Orange silty fine to medium sand (dense, moist)


P=1 to 2 inches

P=1 to 2 inches

P=1 to 2 inches


Eve

rett:

Dat

e:10

/12/

09 P

ath:

P:\8

\803

0006

\00\

GIN

T\80

3000

600.

GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GE

OE

NG

INE

ER

S8.

GD

T/G

EI8

_TE

STP

IT_1

P_G

EO

TEC

Sheet 1 of 1



Figure A-13


Date Excavated:Equipment: 10.5Total Depth (ft)


Test

ing

Sam

ple

Sam

ple

Nam

eTe

stin

g

Dep

th (f

eet)

1

2

3

4

5

6

7

8

9

10

SAMPLE

Gra

phic

Log

Gro

upC

lass

ifica

tion MATERIAL

DESCRIPTION

Enc

ount

ered

Wat

er

Ele

vatio

n (fe

et)

361

360

359

358

357

356

355

354

353

352

REMARKS

Moi

stur

eC

onte

nt, %

APPENDIX D Report Limitations and Guidelines for Use

May 15, 2018 | Page D-1 File No. 8030-010-00

APPENDIX D REPORT LIMITATIONS AND GUIDELINES FOR USE1

This appendix provides information to help you manage your risks with respect to the use of this report.

Geotechnical Services are Performed for Specific Purposes, Persons and Projects

This report has been prepared for use by Shoreline Community College and other members of the design team for use in the design of this project. This report may be made available to prospective contractors for bidding or estimating purposes; but our report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions. This report is not intended for use by others, and the information contained herein is not applicable to other sites.

GeoEngineers structures our services to meet the specific needs of our clients. For example, a geotechnical or geologic study conducted for a civil engineer or architect may not fulfill the needs of a construction contractor or even another civil engineer or architect that are involved in the same project. Because each geotechnical or geologic study is unique, each geotechnical engineering or geologic report is unique, prepared solely for the specific client and project site. No one except Shoreline Community College and members of the design team should rely on this report without first conferring with GeoEngineers. This report should not be applied for any purpose or project except the one originally contemplated.

A Geotechnical Engineering or Geologic Report is Based on A Unique Set of Project-Specific Factors

This report has been prepared for the proposed Allied Health and Manufacturing Buildings project on the Shoreline Community College campus in Shoreline, Washington. GeoEngineers considered a number of unique, project-specific factors when establishing the scope of services for this project and report. Unless GeoEngineers specifically indicates otherwise, do not rely on this report if it was:

■ not prepared for you,

■ not prepared for your project,

■ not prepared for the specific site explored, or

■ completed before important project changes were made.

For example, changes that can affect the applicability of this report include those that affect:

■ the function of the proposed structure;

■ elevation, configuration, location, orientation or weight of the proposed structure;

■ composition of the design team; or

■ project ownership.

1 Developed based on material provided by ASFE, Professional Firms Practicing in the Geosciences; www.asfe.org.

May 15, 2018 | Page D-2 File No. 8030-010-00

If important changes are made after the date of this report, GeoEngineers should be given the opportunity to review our interpretations and recommendations and provide written modifications or confirmation, as appropriate.

Subsurface Conditions Can Change

This geotechnical or geologic report is based on conditions that existed at the time the study was performed. The findings and conclusions of this report may be affected by the passage of time, by manmade events such as construction on or adjacent to the site, or by natural events such as floods, earthquakes, slope instability or groundwater fluctuations. Always contact GeoEngineers before applying a report to determine if it remains applicable.

Most Geotechnical and Geologic Findings are Professional Opinions

Our interpretations of subsurface conditions are based on the Standard Penetration Tests results completed at the site. Site exploration identifies subsurface conditions only at those points where subsurface tests are conducted. GeoEngineers reviewed historic field and laboratory data and then applied our professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ, sometimes significantly, from those indicated in this report. Our report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions.

Geotechnical Engineering Report Recommendations are Not Final

Do not over-rely on the preliminary construction recommendations included in this report. These recommendations are not final, because they were developed principally from GeoEngineers’ professional judgment and opinion. GeoEngineers’ recommendations can be finalized only by observing actual subsurface conditions revealed during construction. GeoEngineers cannot assume responsibility or liability for this report's recommendations if we do not perform construction observation.

Sufficient monitoring, testing and consultation by GeoEngineers should be provided during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not earthwork activities are completed in accordance with our recommendations. Retaining GeoEngineers for construction observation for this project is the most effective method of managing the risks associated with unanticipated conditions.

A Geotechnical Engineering or Geologic Report Could Be Subject to Misinterpretation

Misinterpretation of this report by other design team members can result in costly problems. You could lower that risk by having GeoEngineers confer with appropriate members of the design team after submitting the report. Also retain GeoEngineers to review pertinent elements of the design team's plans and specifications. Contractors can also misinterpret a geotechnical engineering or geologic report. Reduce that risk by having GeoEngineers participate in pre-bid and preconstruction conferences, and by providing construction observation.

Give Contractors a Complete Report and Guidance

Some owners and design professionals believe they can make contractors liable for unanticipated subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems, give contractors the complete geotechnical engineering or geologic report, but preface it with a clearly

May 15, 2018 | Page D-3 File No. 8030-010-00

written letter of transmittal. In that letter, advise contractors that the report was not prepared for purposes of bid development and that the report's accuracy is limited; encourage them to confer with GeoEngineers and/or to conduct additional study to obtain the specific types of information they need or prefer. A pre-bid conference can also be valuable. Be sure contractors have sufficient time to perform additional study. Only then might an owner be in a position to give contractors the best information available, while requiring them to at least share the financial responsibilities stemming from unanticipated conditions. Further, a contingency for unanticipated conditions should be included in your project budget and schedule.

Contractors Are Responsible For Site Safety on Their Own Construction Projects

Our geotechnical recommendations are not intended to direct the contractor’s procedures, methods, schedule or management of the work site. The contractor is solely responsible for job site safety and for managing construction operations to minimize risks to on-site personnel and to adjacent properties.

Read These Provisions Closely

Some clients, design professionals and contractors may not recognize that the geoscience practices (geotechnical engineering or geology) are far less exact than other engineering and natural science disciplines. This lack of understanding can create unrealistic expectations that could lead to disappointments, claims and disputes. GeoEngineers includes these explanatory “limitations” provisions in our reports to help reduce such risks. Please confer with GeoEngineers if you are unclear how these “Report Limitations and Guidelines for Use” apply to your project or site.

Geotechnical, Geologic and Environmental Reports Should Not Be Interchanged

The equipment, techniques and personnel used to perform an environmental study differ significantly from those used to perform a geotechnical or geologic study and vice versa. For that reason, a geotechnical engineering or geologic report does not usually relate any environmental findings, conclusions or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Similarly, environmental reports are not used to address geotechnical or geologic concerns regarding a specific project.

Biological Pollutants

GeoEngineers’ Scope of Work specifically excludes the investigation, detection, or assessment of the presence of Biological Compounds which are Pollutants in or around any structure. Accordingly, this report includes no interpretations, recommendations, findings, or conclusions for the purpose of detecting, assessing, or abating Biological Pollutants. The term “Biological Pollutants” includes, but is not limited to, molds, fungi, spores, bacteria, and viruses, and/or any of their byproducts.

geotechnical engineering services - des.wa.gov · figure b-1 through b-6 – sieve analysis results...

Documents