The URL can be used to link to this page

Home My WebLink AboutGeotechnical Engineering Evaluation Report - COM Engineering / Geo-Tech Reports - 12/28/2005 GEOTECHNICAL ENGINEERING EVALUATION REPORT BELFAIR STARBUCKS BELFAIR, WASIUNGTON Prepared for: STARBUCKS COFFEE COMPANY 3801 EAST FLORIDA AVENUE DENVER, COLORADO 80210 Prepared by: ALKAI CONSULTANTS, LLC 9465 PROVOST ROAD NW, SurrE 202 SILVERDALE, WASMNGTON 98383 Project No.ACL05-12-G113 28 December 2005 1 t ALKAI CONSULTANTS LLC. Environmental Engineering • Geotechnical Engineering • Wetland Consulting 28 December 2005 Project: ACL05-11-G113 Starbucks Coffee Company 3801 East Florida Avenue Ste. 915 Denver, CO 80210 Attention: Ms. Kathy Bowman Subject: Geotechnical Engineering Evaluation Report Starbucks Coffee Belfair, Washington Dear Ms. Bowman, Submitted herewith is a report for ALKAI Consultants, LLC's geotechnical engineering evaluation for the subject project. This evaluation was conducted in accordance with our signed contract agreement dated 22 September 2005. The report presents findings from our geotechnical investigation and provides recommendations for geotechnical aspects of project design and construction. ALKAI Consultants, LLC explored subsurface soil conditions at the site by excavating three exploratory test pits, TP-1 thru TP-3, on 14 December 2005. The test pits were excavated to depths between 8 and 10 feet by a CASE trackhoe. Soils encountered in the test pits consisted of medium dense to dense poorly graded sand with silt and gravel (SP-SM) overlying medium dense silty sand(SM)and silty sand with gravel(SM). A 6-inch layer of peat material was encountered in test pit TP-3 between 8.0 and 8.5 feet. Based on the results of our study, it is our professional opinion that the site is geotechnically suitable for the proposed development. The proposed building can be supported on conventional spread footings, strip footings,or a combination of both,bearing on the dense material found at the site or on properly compacted fill brought into the site. The site soils may be used as structural fill provided they can be compacted to meet the compaction specifications, however, these soils may be moisture sensitive, due to the high percentage of fines, and will be difficult or impossible to compact during wet weather conditions. If earthwork is planned for the winter months ALKAI recommend that a relatively free-draining pit-run sand or gravel be imported to the site for use as structural fill. Site soils may be usable as structural fill during the dry summer months. Please refer to the text of the report for more specific recommendations regarding the site development. We appreciate the opportunity to work with you on this project. If we can be of further assistance or if you have any questions regarding this project,please contact our office. %OBERT Sincerely yours, r,�s .,•....,y'F ` 4' R 15392 q eV George Webster, P.E. �' Shawn E. Williams,L.E.G. Senior Engineer S��' A�. ' /y�/ Senior Engineering Geologist } I Enclosures SAALKA1 Shared files\ProjectAGeotechnica1\05 Projects\ACL05-11-G a fair Starbuckstreport\draft Geotechnical Report.doc 9465 Provost Road NW, Suite 202 • Silverdale, Washington 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 1 Project: ACL05-11-G 113 28 December 2005 Page No. i TABLE OF CONTENTS Page LIST OF TABLES iii LIST OF FIGURES iii 1. INTRODUCTION 1 2. PROJECT CHARACTERISTICS 2 2.01 Site Location and Description 2 2.02 Proposed Construction 2 3. INVESTIGATIONS AND LABORATORY TESTING 3 3.01 Site Reconnaissance 3 3.02 Subsurface Explorations-Test Pits 3 3.03 Laboratory Testing 3 4. SURFACE& SUBSURFACE CONDITIONS 4 4.01 Available Geologic and Soils Information 4 4.02 Surface Conditions 5 A. Topography and Slope Stability 5 B. Surface Water 5 4.03 Site Subsurface Conditions 5 A. Fill Material 5 B. Outwash 5 C. Peat 5 5. DESIGN RECOMMENDATIONS 6 5.01 General 6 5.02 Foundation Support 6 5.03 Drainage and Landscaping 6 5.04 Seismic Design Considerations 7 5.05 Groundwater Influence on Structures 7 6. CONSTRUCTION PROCEDURES AND RECOMMENDATIONS 8 6.01 General 8 6.02 Construction Excavation Slopes 8 6.03 Site Grading and Earthwork 9 A. Site Preparation 9 B. Fill Placement and Compaction 9 C. Structural Fill 9 D. Utility Trench Backfill 10 9465 Provost Road NW, Suite 202 • Silverdale, Washington 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 1 Project: ACL05-11-G113 28 December 2005 Page No. ii E. Recommended Compaction Specifications 10 6.04 Footing Excavations 10 6.05 Groundwater Considerations 11 6.06 Surface Water&Erosion Considerations 11 7. REVIEW AND CONSTRUCTION OBSERVATIONS 12 7.01 Review of Plans and Specifications 12 7.02 Construction Observations 12 8. LDETATIONS 13 TABLES FIGURES APPENDIX A—ALKAI Test Pit and Test Boring Logs with Key APPENDIX B—Laboratory Test Results 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 � r Project: ACL05-11-G113 28 December 2005 Page No. iii LIST OF TABLES Table No. Title 1 Summary of Exploratory Test Pits and Test Borings 2 Summary of Geotechnical Laboratory Test Results LIST OF FIGURES Figure No. Title 1 Vicinity Map 2 Site Plan 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-GI 13 28 December 2005 Page No. I 1. INTRODUCTION ALKAI Consultants, LLC(ALKAI)was retained by Starbucks Coffee Company to conduct a geotechnical evaluation for the proposed Starbucks coffee in Belfair, Washington located in Mason County. The purpose of this investigation was to determine the general subsurface conditions by performing explorations at the project site and provide recommendations for the geotechnical aspects of the project. In preparing for this report, ALKAI has reviewed and/or relied on the following information. • Discussions with Ms. Kathy Bowman of Pacific Starbucks Coffee Company. • Site layout plan prepared by Aspen Land Surveying, LLC dated 18 November 2005. • United States Department of Agriculture's Soil Survey for Mason County, online map & report. • State of Washington's Division of Geology and Earth Resources' Geologic Map GM-50 "Geologic Map of Washington-Northwest Quadrant", dated 2002. • Mason County Resource Ordinance, last revised 10 January 2005. 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-G113 28 December 2005 Page No. 2 2. PROJECT CHARACTERISTICS 2.01 Site Location and Description The site is located in Belfair, Washington in Mason County west of Highway 3 on Clifton Lane in the NE '/4 of the SE of Section 29 Township 23N Range 1 W of the Willamette Baseline and Meridian, as shown in Figure 1. The parcel is rectangular shaped and comprised of approximately 0.5 acres. The site has been previously graded when the Safeway to the northeast was constructed. There are retaining walls on the southeast and the southwest edges of the property. The site is unpaved, but had a thin layer of compacted gravel covering most of the area. In the center of the property there is an underground sewer tank that is visible due to four tubes at the surface. There is a pipe that runs from the sewer tank northwest off of the property. There are multiple other utilities located within the property line. The parcel was accessible from the Safeway parking lot. The subject parcel is bounded to the northwest by a gas station, to the northeast by a Safeway store, to the southeast by State Route 3,and to the southwest by Clifton Lane. 2.02 Proposed Construction ALKAI understands that preliminary plans call for the construction of a Starbucks Coffee on the subject lot. From our understanding this structure will be one story and will have landscaping and customer parking associated with it. 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-G 113 28 December 2005 Page No. 3 3. INVESTIGATIONS AND LABORATORY TESTING 3.01 Site Reconnaissance ALKAI representatives performed a site reconnaissance of the property during the field investigation on 14 December 2005. 3.02 Subsurface Explorations-Test Pits Three exploratory test pits (TP-1 through TP-3) were performed on the site 14 December 2005 to investigate subsurface conditions and obtain samples to aid in the determination of engineering properties and soil conditions of the subsurface materials. The test pit locations were located within the development area as shown on Figure 2. A summary of the test pits is presented in Table 1 and test pit logs can be found in Appendix A. Test pits were extended to depths of 8.0 to 10.0 feet below existing grade using a CASE track hoe CX160 with a 36 inch bucket. Liberty Bay Excavating of Poulsbo, Washington, excavated the test pits as a subcontractor to ALKAI. The subsurface conditions revealed by the field investigation are discussed in Section 4. The letters in parentheses following the soil description are Unified Soil Classification Systems (USCS) soil classifications according to ASTM D2487/D2488. A sheet defining terms used on the test pit logs is provided immediately preceding the logs. The test pit logs were adjusted to reflect laboratory test results where appropriate. Groundwater observations, sampling information, and other pertinent field data and observations are also included on the logs. 3.03 Laboratory Testing To aid in classifying the soils and to determine general soil characteristics, laboratory tests were performed on selected representative samples. Test method references are shown in the following table. Phoenix Soil Research of Kingston, Washington was retained to provide geotechnical laboratory analysis. Parameter Testin Method Reference Sieve Analysis ASTM D422 Moisture Content ASTM D2216 The results of the laboratory testing are summarized in Table 2 and laboratory test reports are provided in Appendix B. 9465 Provost Road NW, Suite 202 9 Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-G113 28 December 2005 Page No.4 4. SURFACE & SUBSURFACE CONDITIONS 4.01 Available Geologic and Soils Information The subject site lies within the central Puget Lowland. The lowland is part of a regional north-south trending trough that extends from southwestern British Columbia to near Eugene, Oregon. North of Olympia, Washington, this lowland is glacially carved with a depositional and erosional history including at least four separate glacial advance/retreats. The Puget Lowland is bounded on the west by the Olympic Mountains and on the east by the Cascade Range. The lowland is filled with glacial and nonglacial sediments consisting of interbedded gravel, sand, silt,till, and peat lenses. The Geologic Map of Washington-Northwest Quadrant indicates that the site is located on advanced outwash(Qga)near a contact with till (Qgt). Advanced outwash consists of glacialfluvial sand and gravel, and lacustrine clay, silt and sand deposited during the advance of glaciers. The till consists of unsorted, unstratified, highly compacted mixture of clay,silt, sand, gravel, and boulders deposited by glacial ice. The United States Department of Agriculture (USDA) Soil Survey of Mason County Area, Washington, information indicates the following soil type exists on the project site: • Grove gravelly sandy loam, 0 to 5 percent slopes. The soil survey description of this soil type is summarized in the following table. USDA Soil Eh—Grove Gravelly Sandy Loam Survey Name USCS Soil 0-7 inches,gravelly sandy loam,SM Type 2-24 inches,very gravelly loamy sand,very gravelly sandy loam,extremely gravelly sand,GP-GM 24-60 inches,Very gravelly coarse sand,very gravelly sand,extremely gravellycoarse sand,GP Origination Vashon glacial drift Typical Profile The surface soil consists of reddish-brown, gravelly sandy loam, 6 inches thick. It is very friable, is single grained, and contains a few small, round shots. The upper part of this layer contains a few firm, irregular, more reddish aggregates. The next layer extends to depths ranging from 12 to 14 inches. It is similar to the surface soil, except that is more gravelly, contains less shot,and the gravel is stained and coated with dark reddish-brown fine material. The subsoil is light brown,very gravelly loamy sand.It is loose, is single grained, and contains no shot. At depths ranging from 24 to 32 inches,the subsoil grades to the substratum of loose gravel, cobbles and sand. The dominant colors are gray,grayish-brown,yellowish-brown, and light brown. Much of the gravel is highly stained with nearly black and reddish-brown,material. In places the upper 24 inches of the substratum is compact or weakly cemented. Drainage Somewhat excessively well drained. Permeability Rapid Surface Runoff Very slow Erosion Hazard Slight Development This soil is in capability subclass VIs. Considerations 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-G113 28 December 2005 Page No. 5 4.02 Surface Conditions A. Topography and Slope Stability The site topography was flat due to previous grading of the lot. The site has a total relief of approximately 7 feet, from elevation 107 at the southeast corner of the property to elevation 100 feet at the northwest corner of the property. Base on our site visit and a review of Mason County Code this site does not appear to be an area of geologic hazard or geologic concern as outlined in Mason County Resource Ordinance section 17.01.100. After visual observation the site soils appear to be stable. B. Surface Water No surface water was observed on the property at the time of the site investigation. There was ground water found in Test Pits TP-2 and TP-3 between 7 and 9 feet. 4.03 Site Subsurface Conditions In general, subsurface conditions encountered in the test pits were consistent in the development area. From the surface to depths ranging from 5.0 to 8.0 feet there was fill material. Below the fill was native outwash material. Between the fill and native material a geotextile fabric was encountered. In test pit TP-3 there was a six-inch layer of peat at 8.0 feet with more outwash below. Groundwater was encountered in test pits TP-2 and TP-3. For a more detailed description of the subsurface conditions, please refer to the test pit logs in Appendix A and Table 1. General descriptions of the predominant materials encountered are presented below. A. Fill Material Two types of fill material were encountered in each test pit. From ground surface to between 1.5 and 5.0 feet was medium dense, brown, poorly graded sand with silt and gravel(SP-SM). Below this fill layer to between 5.0 and 8.0 feet was more fill that was medium dense, gray-brown, poorly graded sand with silt and grave] (SP-SM). The first layer of fill had noticeably larger gravel as well as more gravel then the fill below it. This material was moist. The fill material was placed over a geotextile fabric. B. Outwash Outwash was encountered in test pits TP-2 and TP-3. The top of this stratum was encountered at depths ranging from 5.0 to 8.0 feet bgs and extended to the bottom of exploration. This stratum consisted of medium dense, mottled brown and gray, silty sand with gravel(SM), and silty sand (SM). There was wood debris found in the outwash in test pit TP-3. This material was moist to wet. C. Peat Peat was encountered in test pit TP-3 within the outwash layer from 8 to 8.5 feet bgs. This material was loose,dark brown, silty sand (SM). There was wood debris found in this layer. This material was moist. 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 I Project No. ACL05-11-G113 28 December 2005 Page No. 6 5. DESIGN RECOMMENDATIONS 5.01 General The recommendations for design and construction presented in the following sections are based on ALKAI's understanding of the proposed construction (Section 2), an engineering assessment of the anticipated subsurface conditions (Section 4), and experience with similar projects in similar soil conditions. If there is any change in these project criteria, including project location on the site, a review should be made by ALKAI prior to final design and construction at the site. The design recommendations included in this report do not apply to future structures. 5.02 Foundation Support Based on the observed subsurface conditions, shallow foundations appear to be adequate to support the proposed structures. ALKAI assumes that these structures will be founded on conventional spread footings, strip footings, or a combination of both, bearing on the dense material found at the site or on properly compacted fill brought into the site. A maximum net allowable bearing pressure of 2,000 pounds per square foot (psf) should be used for design of foundations on dense soil at the site and 2,000 psf on residuum or granular fill generated on site or imported into the site. The recommended minimum dimension of continuous or isolated footings is 18 inches wide. Field observations and testing of the open foundation excavation should be performed prior to concrete placement to verify that the subgrade is suitable for foundation placement or to make mitigative recommendations as appropriate. Exterior wall footings and footings in unheated areas should be located at a depth of at least 18 inches below final exterior grade for frost protection. All interior footings can be located at nominal depths below finished floor provided topsoil and other undesirable materials are removed. It is our understanding that there will be a concrete slab on grade. The area of the slab should be constructed with a 4 inch minimum concrete slab over 2 inches of clean washed sand, a vapor barrier over 2 inches of clean washed sand over 6 inches of gravel. Total resulting foundation settlements are not expected to exceed about 0.50 inch, with differential movements of approximately 0.50 inch. 5.03 Drainage and Landscaping To prevent saturation of foundation backfill, positive drainage should be provided at the site. Construction details should ensure that surface water does not penetrate into utility trenches and migrate beneath the structures. All landscaping, pavements, sidewalks and parking areas should be sloped away from any of the structures to prevent ponding of water. A minimum slope of 2 percent in the first 10 feet from the building is recommended. Roof drains should be tightlined away from foundations. If any landscaping is used, plants should not be located within a distance of 5 feet from the building. Irrigation systems should be arranged so that water under full pressure does not spray within 5 feet of foundation walls. If lawn edging is used around the exterior of a building, it should be perforated to prevent ponding of surface water in the vicinity of the backfill soils. The exterior backfill should not be covered with a polyethylene moisture barrier. Instead, a weed suppressant geotextile fabric, such as Mirafi 140S or equivalent, may be used to allow for natural evaporation of the backfill soils. 9465 Provost Road NW, Suite 202 9 Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-G 113 28 December 2005 Page No. 7 The free flow of water toward or over steep slopes should be avoided due to the potential erosion hazard. Landscaping should not be designed to direct runoff into these areas. Runoff from impervious surfaces should be intercepted and discharged away from these slopes with care not to affect down slope structures by using appropriate water conveyance systems 5.04 Seismic Design Considerations The site is located in the seismically active Puget Sound region. Based on observed subsurface conditions and assuming that fill is properly placed, the potential for liquefaction and/or unstable slopes during a seismic event appears to be low. ALKAI has reviewed Table 1615.1.1 Site Class Definitions of the 2003 International Building Code (IBC) and determined that the overall soil profile has a site class definition of"D"—Stiff Soil Profile. Site-specific ground motions were not determined for the site. Based on information obtained from the National Seismic Hazard Mapping Project (NSHMP) website the probabilistic peak ground acceleration (PGA), in percent of gravity (% g), are 0.32g and 0.55 g for ground motion with, respectively, 10 percent, and 2 percent probability of exceedance in a 50-year period. The ground motion values for the 0.2 second period spectral acceleration (SA), and 1.0 second period SA) for 10%, probability of exceedance in 50 years is 0.70g and 0.24g,respectively,and for 2%probability of exceedance in 50 years is 1.22g and 0.44g, respectively. 5.05 Groundwater Influence on Structures Groundwater was encountered as described in Section 3.03 of this report. At the time of our investigation, groundwater was not encountered within anticipated excavation depths at the site. Foundation design should include a perimeter footing system, consisting of a 4-inch perforated rigid pipe placed along the exterior building foundation at the footing subgrade elevation and imbedded in a free-draining sand and gravel material. This drainage system should be designed to transport water away from the building foundation and discharge into an appropriate area. Roof drainage should not be connected to the perimeter foundation drainage system. However, the same outfall piping if connected well away from the building such that roof water will not backup into the footing drains would be acceptable. Asphalt Pavement Design The near surface subgrade soils are considered "good" subgrade material for asphalt pavement design. A resilient modulus (MR).of 20,000 pounds per square inch for the subgrade soils should be used for alternate pavement design purposes. The following table shows the Washington Asphalt Pavement Association (WAPA) recommended pavement sections for light traffic and heavy traffic for asphalt-paved parking lot areas. Minimum Pavement Thickness and Design—Aggregate Base Thickness of Class A or Class B Asphalt(inches) Thickness of Aggregate Base(inches) Light Traffic 3 4 Heavy Traffic 4 4 Minimum Pavement Thickness and Desi n—Full Depth Asphalt Thickness of Class A or Class B Asphalt(inches) Thickness of Asphalt Treated Base(ATB)(inches) Light Traffic 2 3 Heavy Traffic 2 4 The subgrade should be proofrolled to verify stability in accordance with Section 6.03 of the final report; if the proofroll reveals soft or loose soils,the subgrade should be stabilized according to Section 6.03 of the report. 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-G113 28 December 2005 Page No. 8 6. CONSTRUCTION PROCEDURES AND RECOMMENDATIONS 6.01 General Variations in soil conditions possibly will be encountered during construction. In order to correlate design concepts with actual soil conditions encountered during construction, ALKAI recommends that technical or engineering personnel be present to provide monitoring and geotechnical engineering services during construction and to assist in developing design changes in the event that subsurface conditions differ from those outlined in this report. ALKAI can be retained to provide these services. The following sections of this report include comments on items related to excavation, foundation construction, earthwork, and related geotechnical engineering aspects of the proposed construction. This section is written primarily for the engineer responsible for the preparation of plans and specifications. This section also addresses construction issues related to foundations and earthwork and will aid personnel who monitor construction activity. The Contractor must evaluate potential construction problems on the basis of their own knowledge and experience in this area and on the basis of similar projects in other localities, taking into account their own proposed construction methods and procedures. 6.02 Construction Excavation Slopes The Contractor should become familiar with and be aware of applicable local, state, and federal safety regulations, including the current Washington Industrial Safety and Health Act (WISHA). Construction site safety is the sole responsibility of the Contractor, who shall also be solely responsible for the means, methods, and sequencing of construction operations. ALKAI is providing this information solely as a service to our client. Under no circumstances should the information provided below be interpreted to mean that ALKAI is assuming responsibility for construction site safety or the Contractor's activities; such responsibility is not being implied and should not be inferred. The Contractor should be aware that slope height, slope inclination, or excavation depths should in no case exceed those specified in local, state, or federal safety regulations, e.g., WISHA rule for, Excavation, Trenching, and Shoring, Chapter 296-155 - Part N & OSHA Health and Safety Standards for Excavations, 29 CFR Part 1926, or successor regulations. Such regulations are strictly enforced and, if they are not followed, the Contractor and its subcontractors could be liable for substantial penalties. For this site, subsurface conditions encountered include compacted fill outwash materials. Fine grained soils are considered Type C soils when applying the WISHA regulations. For excavations less than 20 feet deep WISHA recommends a maximum slope incline of 1.5H:1 V(horizontal to vertical)for Type C soils. The soils to be penetrated by the proposed excavations may vary significantly across the site. ALKAI's preliminary soil classification is based solely on the materials encountered in widely spaced exploratory test pits. The Contractor should continually classify the soils that are encountered as excavation progresses with respect to the WISHA system. For excavations that are extended to a depth of more than 20 feet it will be necessary to have the side slopes designed by a professional engineer registered in the State of Washington. This side slope design should be a required construction submittal. As a safety measure, all vehicles and soil stockpiles should be kept a minimum lateral distance of 2 feet from the crest of the slope as required by OSHA. The exposed slope face should be protected against the elements. 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-G 113 28 December 2005 Page No. 9 6.03 Site Grading and Earthwork During wet weather conditions, problems may- be encountered with site grading and earthwork due to high moisture content within the soil, disturbance of sensitive soils, and the possible presence of shallow or perched groundwater. If possible, ALKAI recommends that site grading and foundation installation be performed during dry weather conditions. A. Site Preparation All areas that will support footings, floor slabs, exterior concrete and pavements should be properly prepared. All wood debris at the near surface should be removed and not incorporated into any fill materials. After rough grade has been established in cut areas and prior to placement of fill in fill areas,the exposed subgrade should be carefully inspected by probing and testing as needed. Any topsoil or other organic materials still in place, frozen, wet, soft, or loose soil and other undesirable materials, as determined by the geotechnical engineer, should be removed. The exposed subgrade should furthermore be evaluated by proof rolling with a heavyweight vehicle to check for pockets of soft material hidden beneath a thin crust of dense soil. Any unsuitable materials thus exposed should be removed. The exposed materials should be scarified, and moistened or dried if necessary, to a minimum depth of 8 inches. The scarified material should then be compacted as outlined in Section 6.03E of this report. Areas where stable soils are encountered at subgrade levels should also be scarified and compacted as outlined in section 6.03E prior to fill placement. Buried structures encountered during construction should be properly removed and backfilled. Any septic tanks, underground storage tanks, debris pits, cesspools, or similar structures should be entirely removed. Concrete footings should be removed to an equivalent depth of at least 3 feet below proposed foundation elevations or as recommended by a geotechnical engineer. Care should be exercised during the grading operations at the site. The grading should be done during dry weather conditions, if at all possible. Due to the nature of the near-surface soils, the excessive traffic of heavy equipment (including heavy compaction equipment) may create pumping and general deterioration of the shallower soil if excess surface water is present. B. Fill Placement and Compaction Fill should be placed in maximum 8-inch loose lifts and compacted according to the specifications outlined in Section 6.03E of this report. Only lightweight compaction equipment(hand held or walk-behind) should be operated adjacent to foundation, retaining, and vault walls. Field density tests should be performed on each lift as necessary to verify that adequate compaction is being achieved. Compaction of any material by flooding is not considered acceptable. This method will generally not achieve the desired compaction and the large quantities of water will tend to soften and/or cause swelling of the subgrade soils. C. Structural Fill Imported structural fill should be non-plastic material with less than 15 percent fines (percent passing the No. 200 sieve). On-site granular soils derived from the residuum is considered suitable for structural fill, however it may be moisture sensitive due to it's percentage of fines. Any fine soils, consisting of silt or clay material are not considered suitable for structural fill. Any imported structural fill should be tested and approved prior to use at the site. 9465 Provost Road NW, Suite 202 • Silverdale. WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-G113 28 December 2005 Page No. 10 D. Utility Trench Backfill Utility trench backfill placed in or adjacent to buildings and exterior slabs should be compacted as recommended in Section 6.03E of this report. Pipe bedding should be in accordance with pipe manufacturer's recommendations. E. Recommended Compaction Specifications Recommended compaction specifications are provided below. Material Not Exhibiting a Material Exhibiting a Well-Defined Well-Defined Moisture- Moisture-Density Relationship Density Relationship Fill Type Minimum%of Moisture Content Relative to Optimum Modified Proctor Moisture Content Minimum Relative Density (ASTM D 1557) (ASTM D 4253 and D 4254) Maximum Dry Density Granular Soils Cohesive Soils Structural fill and recompacted native 95% -2 to+2% Not 75% soils beneath footings. Recommended Structural fill and recompacted native 95% -2 to+2% Not 70% soils beneath floor Recommended slabs. Structural fill and recompacted native soils behind 90% -2 to+2% Not 65% foundation and Recommended retaining walls. Structural fill and recompacted native soils beneath 95% -2 to+2% -1 to+3% 70% pavements,exterior concrete,and general site fill. Utility trench backfill in or adjacent to 95% -2 to+2% -1 to+3% 70% buildings and exterior slabs. 6.04 Footing Excavations Each foundation excavation should be observed to verify that any existing uncontrolled man-made fill, loose, soft, or otherwise undesirable materials are removed and that the footings will bear on satisfactory material. At the time of such observation, it may be necessary to make hand auger borings and/or use a hand penetration device in the base of the foundation excavation to confirm that the soils below the base are satisfactory for foundation support. The necessary depth of penetration will be established during observation. If soft/loose pockets or undesirable materials are encountered in the footing excavations and it is inconvenient to lower the footings, the proposed footing excavations may be re-established by backfilling after the material has been removed. This backfilling may be done with a well-compacted, suitable, structural fill. The fill should be placed and compacted according to specifications outlined under Section 6.03E of this report. Soils exposed in the base of all satisfactory foundation excavations should be compacted to the specifications outlined in Section 6.03E and should also be protected against any detrimental change in conditions such as from disturbance, rain 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 I Project No. ACL05-11-G 113 28 December 2005 Page No. 11 and freezing. Surface run-off water should be drained away from the excavation and not allowed to pond. If possible, all footing concrete should be poured the same day the excavation is made. If this is not practical, the footing excavations should be adequately protected. 6.05 Groundwater Considerations Groundwater conditions are described in Section 4 of this report. At the time of our investigation, groundwater was not encountered within anticipated excavation depths at the site. Groundwater fluctuates seasonally and thus may increase during the wetter seasons,but the need for construction dewatering at this site is not anticipated. However, if groundwater seepage is encountered during construction, it can be controlled by sloping the bottom of the excavation to drain to shallow sump pump pits. 6.06 Surface Water&Erosion Considerations Disturbed soils may be easily eroded by channelized water or sheet flow from storm runoff. Erosion and sediment control (ESC) should be used to minimize the transportation of sediment to wetlands, streams, lakes, drainage system and adjacent properties. Since the site is not directly adjacent to surface water, ALKAI recommends that basic ESC measures for this site will be sufficient. Such measures include silt fences at the perimeter of the construction area, and protection for any existing storm sewer inlets that may be affected by the construction. Site preparation and excavation work should be competed during normally drier portions of the year. During periods of heavy rainfall, ditches should be used to divert water away from stripped areas and visqueen should be used to cover slopes and soil stockpiles to prevent excessive surface erosion. Complete regulation information on construction stormwater pollution prevention can be found in"Stormwater Management Manual for Western Washington,Volume H-Construction Stormwater Pollution Prevention',prepared by the Washington State Department of Ecology, Water Quality Program, dated February 2005 (Publication No. 05-10-30). 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-G113 28 December 2005 Page No. 12 7. REVIEW AND CONSTRUCTION OBSERVATIONS 7.01 Review of Plans and Specifications The recommendations outlined in this report are based on preliminary site plans. In order for the design and construction recommendations provided in this report to be valid, ALKAI needs to review the final site plan layout prior to their release for bidding. 7.02 Construction Observations Variations in subsurface conditions will likely be encountered during construction at the site. To permit correlation between the investigation data and the conditions encountered during construction, and to provide conformance with the plans and specifications as originally contemplated, it is recommended that a geotechnical engineer be retained to provide continuous observations of construction operations and to provide quality control testing of fill, asphalt and base course placement and compaction. ALKAI can be retained to provide these services. 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No. ACL05-11-G113 28 December 2005 Page No. 13 8. LBUTATIONS This report has been prepared for Starbucks Coffee Company regarding the subject project. Information presented in this report has been collected and interpreted in a manner consistent with the level of care and skill ordinarily P rP exercised b Y Y members of the profession currently practicing under similar conditions, and in accordance with sound and generally accepted principles consistent with normal consulting practice. No other warranty, expressed or implied, including (but not limited to)any warranty or merchantability or fitness for a particular use has been made. Starbucks Coffee Company and ALKAI discussed the risks and rewards associated with this project, as well as ALKAI's fee for services. Starbucks Coffee Company and ALKAI agreed to allocate certain of the risks so that,to the fullest extent permitted by law, ALKAI's total aggregate liability to Starbucks Coffee Company is limited to $50,000 or the fee, whichever is greater, for any and all injuries, claims (including any claims for costs of defense or other incurred costs), losses, expenses, or damages whatsoever arising out of or in any way related to ALKAI's services for this project, from any cause or causes whatsoever, including but not limited to, negligence, errors, omissions, strict liability, breach of contract, breach of warranty, negligent misrepresentation, or other acts giving rise to liability based upon contract tort, or statute. In the event that change in the nature, design, or location of the proposed construction is made, or any physical changes to the site occur, recommendations are not be considered valid unless the changes are reviewed by ALKAI and conclusions of this report are modified or verified in writing. The subsurface exploration logs and related information depicts conditions only at the specific locations and at the particular time designated on the logs. The passage of time may result in a change of subsurface conditions at these exploration locations. Subsurface conditions at other locations may differ from conditions occurring at the exploration locations. The nature and extent of variations of subsurface conditions between explorations are not known. If variations appear during additional explorations or construction,reevaluation of recommendations in this report may be necessary. Stratification lines designating the interface between soil types in subsurface exploration logs represent approximate boundaries. The transition between materials may be gradual. Analyses and recommendations provided in this report are based in part upon the data obtained from the subsurface explorations. The scope of ALKAI services did not include an environmental assessment for the presence or absence of 1) hazardous and/or toxic materials, in the soil,groundwater, surface water,or atmosphere, and 2)wetlands. Any statements or absence of statements in this report on any subsurface exploration log regarding staining or odor of soil, groundwater, or surface water, unusual or suspicious items, or conditions observed are strictly descriptive information for Starbucks Coffee Company SAALKA1 Shared fi1es\Projects\Geotechnica1\05 Projects\ACL05-11-G113 Belfair Starbucks\report\draft Geotechnical Report.doc 9465 Provost Road NW, Suite 202 • Silverdale, WA 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 TABLE 1 SUMMARY OF EXPLORATORY TEST PITS BELFAIR STARBUCKS BELFAIR, WASHINGTON Ground Surface Depth to dense material Test Boring Elevation' (feet) Total Depth(feet) Depth to Groundwater(feet) (feet) TP-1 _104_5 8.0 Not Incountered 5.0 TP-2 105 _ 9.0 --— — 9.0 5.0 TP-3 104 10.0 — 7.0 1.5 Notes: 'Test Pit elevations are estimated based on site plan provided by Aspen Land Surveying LLC,dated November 2005 S:IALKAI Shared files\Projects\Geotechnica1105 Projects\ACL05-11-G113 Belfair Starbucks\report\[Tables.xls]Table 2 Page 1 of 1 TABLE 2 SUMMARY OF GEOTECHNICAL LABORATORY TEST RESULTS BELFAIR, STARBUCKS BELFAIR, WASHINGTON Sample Moisture Test Sample Depth Content Gravel Sand Silt/Clay USCS Boring No. (feet) N N (%) (%) Symbol USCS Soil Description TP-1 S-1 2.0 8.0 29.1 61.3 9.6 SP-SM Poorly graded SAND with silt and gravel TP-1 S-2 5.5 7.0 30.3 61.9 7.8 SP-SM Poorly graded SAND with silt and gravel TP-2 I S-1 1 9.0 1 22.0 1 18.0 53.4 1 28.6 1 SM Silty SAND with gravel Notes: Additional moisture content laboratory results are included in the boring logs. SAALKAI Shared files\Projects\Geotechnical\05 ProjectslACL05-11-G113 Belfair StarbuckstreportUTables.xls]Table 2 Page 1 of 1 tirzV Ait�i . I e ! Gr vel .' I � � I APPROXIMATE SITE LOCATION Sviva RIVER fair a v 0 A S f State Highway 3 xkff �7 _ I t11ol2 Hngre PArt A N Figure adapted from Topozone.com FIGURE 1 VICINITY MAP y A LK A I CONSULTANTS, LLC. Project Name: Belfair Starbucks Location: Belfair, Washington Environmental Engineering•Geotechnical Engineering•Wetland Consulting Project NO.: ACL05-11-G113 Client: Starbucks Coffee Company i APPENDIX A ALKAI Test Pit Logs with Key Soil Rock Soil descriptions of exposed soil and soil samples on logs of subsurface explorations are based on ASTM Rock descriptions noted on logs of subsurface exploration are based on visual-manual examination of D2488 Standard Practice for Description and Identification of Soils(Visual-Manual Procedure). Description exposed rock outcrops and core samples. The criteria,descriptive terms and definitions used are as follows: includes Unified Soil Classification System(USCS)Classification,density consistency,moisture,and ROD geologic interpretation.The criteria,descriptive terms and definitions are as follows: Rock Quality Designation—Sum of the lengthof recovered core pieces p greater than or equal to 4 inches divided by the theoretical length of rock cored. Density or consistency Recovery Recovery Ratio—length of core recovered divided by the theoretical length of rock cored. Density of SPT Consistency of SPT Field Hardness: A measure of resistance to scratching. Cohesionless soils (Blows per ft) Cohesive Soils (Blows per ft) Very Hard Cannot be scratched with a knifepoint or sharp pick. Very Loose 0-4 Very soft 0-2 Breaking of hand specimen requires several hard blows of geologist pick. Loose 5-10 Soft 3-4 Medium 11-30 Medium 5-8 Hard Can be scratched with a knife point or pick only with difficulty. Hard blow of hammer Dense 31-50 Stiff 9-15 required to detach hand specimen. Very Dense over 50 Very stiff 16-30 Moderate) Can be readily scratched with a knife or pick.Gouges or Y Y p� g grooves%.inch deep can be Hard over 30 Hard excavated by hard blow of point of geologist's pick.Hand specimens can be detached by Penetration Resistance moderate blow. Standard Penetration Test(ASTM D-1586)—Number of blows required to drive a standard 2 inch O.D.split Medium Hard Can be grooved or gouged 1/16 inch deep by firm pressure on knife or pick point. Can spoon sampler 6 inches with a 140 lb.Weight falling freely through 30 inches. Penetration values(N-values) are generally counted over the lower 12 inches of sampler penetration. In test pits,density or consistency is be excavated in small chips to pieces about 1 inch.Maximum size by hard blows of the determined by probing and excavation difficulty. point of a geologist's pick. Color Soft Can be grooved or gouged easily with a knife or pick point.Can be excavated in chips to Basic colors and combinations:black,brown,gray,yellow-brown,etc. pieces several inches in side by moderate blows of a pick point.Small thin pieces can be Moisture Content broken by finger pressure. Very Soft Can be carved with a knife and excavated with a pick point.Pieces 1 inch or more in Dry Absence of moisture,dusty,dry to the touch.Moist Damp but no visible water. thickness can be broken with finger pressure.Can be scratched easily by fingernail. Weathering: The action of organic and inorganic and chemical and physical processes resulting in alteration Wet Visible free water,usually soil is below water table. of color,texture and composition. Fresh No visible sign of alteration,except perhaps slight discoloration on major Laboratory Testing Results discontinuous surfaces. M.C.=Moisture Content Slight Discoloration or rock material and discontinuity surfaces.P.L.=Plastic Limit Moderate Less then half the rock decomposed to soil.Some fresh rock;continuous L.L.=Liquid Limit `framework'. P.I.=Plasticity Index High More then half the rock material decomposed and/or disintegrated to soil.Fresh Gravel:Material passing the 3-inch sieve but retained on the#4 standard sieve. rock corestones or discontinuous`framework'. Sand:Material passing the#4 standard sieve but retained on the#200 standard sieve. Complete All rock material disintegrated[o soil,but mass still intact. 4200:Fines content. Material cla or silt Residual Soil All rock material converted to soil.Volume of mass changed,but material has not ( Y ) passing the#200 standard Sieve. been significantly transported. Texture: Aphanitic Individual grains invisible. (Igneous/metamorphic only) Legend Fine-grained Grains barley visible to the unaided eye,up to 1/16 inch diameter. BOE: Bottom of exploration Medium-grained Grains between 1/16 and 3/16 inch diameter. SPT: Split Spoon Sample Coarse-grained Grains between 3/16 and%4 inch diameter. MPS: Maximum particle size Very coarse-grained Grains larger than inch. Solid line: Indicates contact between two geologic units Bedding: "....."...........................Dashed line: Indicates change in USCS classification of soils within the same geologic unit. Term Inches Term Inches Note: In test borings sample often contains soil material`cored'into the sampler after sampling had occurred Extremely thin <0.75 Thick 24-80 resulting in grater recovery that the sample length_ This material is incorporated into the collection sample. Very thin 0.75-2.5 Very thick 80-240 Thin 2.5-8 Extremely thick >240 Medium 8-24 A LK A 1 CONSULTANTS, LLC. Environmental Engineering•Geoterhnical Engineering•Wetland Consulting Subsurface Exploration Key ALKAI CONSULTANTS , LLC. Environmental Engineering • Geotechnical Engineering • Wetland Consulting TEST PIT TP- 1 Project Name: Belfair Starbucks Test Pit Elevation: 104.5 Client: Starbucks Coffee Company Test Pit Location: See Site Plan Project Number: ACL05-11-G 113 Depth to Groundwater: Not encountered E� z w LABORATORY VISUAL PHYSICAL DESCRIPTION w �, w x x TESTING w w o a RESULTS w FOR SAMPLE A A U v� v1 cn A 0 Medium dense,brown poorl y y graded SAND with silt and gravel(SP-SM),moist,MPS=2 inches. (PIT RUN/FILL) S-1 Grab 2.0 7Grave7=� Sand=61.3% Fines=9.6% 5 5.0 .............................................................................................................................................. Dense,gray-brown,poorly graded SAND with silt and gravel S-2 Grab 5.5 M.C.=7.0% (SP-SM),moist,MPS=1/4 inch. Gravel=30.3% (FILL) Sand=61.9% Fines=7.8% Geotextile fabric encountered at 8 feet. BOE @ 8 feet. No ground water. 10 No Sloughing. 15 Excavation Contractor: Liberty Bay Excavation Date: 12/14/2005 Excavating ACL Representative: SAK Equipment: CASE TRACK HOE CX160 Page 1 of 1 Bucket Width: 36 inches 1 1 ALKAICONSULTANTS, LLC. Environmental Engineering • Geotechnical Engineering • Wetland Consulting TEST PIT TP-2 Project Name: Belfair Starbucks Test Pit Elevation: 105.0 Client: Starbucks Coffee Company Test Pit Location: See Site Plan Project Number: ACL05-11-G113 Depth to Groundwater: Moderate seepage at 9 feet 171 w _ I-4 LABORATORY v VISUAL PHYSICAL DESCRIPTION wo W TESTING x RESULTS w w O w Q U FOR SAMPLE L� rr� rn v� q 0 Medium dense,brown,poorly graded SAND with silt and gravel(SP-SM),moist,MPS=2 inches. (PIT RUN/FILL) 5 5.0 Dense,gray-brown,poorly graded SAND with silt and gravel (SP-SM),moist,MPS='/,inch. (FILL) 8.0 Medium dense,mottled brown,silty SAND with gravel(SM), S-1 Grab 9.0 M.C.=22% moist to wet,MPS=1/,inch. Gravel= 18.0% 10 (OUTWASH) Sand=53.4% = Moderate seepage at 9 feet from southwest comer of test pit. Fines 28.6% Moderate sloughing from 5 to 9 feet on south and north sidewall. BOE @ 9 feet. 15 Moderate seepage at 9 feet. Moderate sloughing from 5 to 9 feet. Excavation Contractor: Liberty Bay Excavation Date: 12/14/2005 Excavating ACL Representative: SAK Equipment: CASE TRACK HOE CX160 Page 1 of 1 Bucket Width: 36 inches ALKAI CONSULTANTS LLC. Environmental Engineering - Geotechnical Engineering - Wetland Consulting TEST PIT TP-3 Project Name: Belfair Starbucks Test Pit Elevation: 104.0 Client: Starbucks Coffee Company Test Pit Location: See Site Plan Project Number: ACL05-11-G113 Depth to Groundwater: Moderate seepage at 7 and 8 feet. w w w O v Z w LABORATORY VISUAL PHYSICAL DE SCRIPTION w w w TESTING W w Z a H RESULTS Q Q O d W FOR SAMPLE Q 0 Medium dense,brown,poorly graded SAND with silt and gravel(SP-SM),moist,MPS=2 inches. 1.5 ....................................................................(PI.T..RUN/.EILL)......................................................,,..,... Dense,gray-brown,poorly graded SAND with silt and gravel (SP-SM),moist,MPS=%inch. (FILL) 5 5.0 Medium dense,gray,silty SAND with gravel(SM),moist to wet.Interlayered blue-grey silt from 5 to 8 feet. Wood debris at 7 feet.Log approximately 4 feet long. Moderate seepage at 7 feet from south side wall.Sloughing 8.0 from 5 to 10 feet in south side wall. 8.5 OUTWASH Loose to medium dense,dark brown,silty sand(SM),moist. Wood debris. 10 S-1 Grab 10.0 M.C.=38% Medium dense,gray,silty sand(SM),wet. Some cementation. Moderate seepage at 8.5 feet from east side wall. Sloughing from 8.5 to 10 feet in east side wall. (OUTWASH) 15 BOE @ 10 feet. Moderate seepage at 7 and 8.5 feet. Sloughing from 5 to 10 feet in south sidewall and 8.5 to 10 feet in east side wall. Excavation Contractor: Liberty Bay Excavation Date: 12/14/2005 Excavating ACL Representative: SAK Equipment: CASE TRACK HOE CX160 Page 1 of 1 Bucket Width: 36 inches APPENDIX B APPENDIX B Laboratory Test Reports ALKAI ConSultants, LLC Belfair C;ffee ACL05-11-G113 Moisture Contents ASTM D-2216 Table 1 MExploration Sam leENumberMDepth(Iftl) Moisture C 10.0 ontent /S 8 S 7 S 22 S Phoenix Soil Research PSR05-1-1204 Page 1 I Particle Size Distribution Report O O O O O O 4 s m M r M as V 2 *1 - ai U" 100 I I I I I I I I I I I I I 90 I I I I I I I I I I I I I I I I I I I I I I I I I so I I 111 70 I I I III I I I I I I I I I I I I I I I I I I I Z 60 LL I I I I I I I I I I I I I I Z 50 I I I I I I I I I I I I I W I I I I I I I I I I I I I I I I I I I I I I I I I I W 40 C- I I I I I I I I I I I I I 30 I I I I I I I I I I I I I I I I I I I I I I I I I I I I l l I I I I I I I I 20 I I I I I I I I I I I I I 10 I I I I I I I I I I I I I I I I I I I I I I I I I I 0 i 100 10 1 0.1 0.01 0.001 GRAIN SIZE-mm. +3" %GRAVEL %SAND %SILT I %CLAY USCS AASHTO PL LL 0 0.0 29.1 61.3 9.6 SP-SM 0.0 30.3 61.9 7.8 SP-SM Al0.0 18.0 53.4 28.6 SM SIEVE PERCENT FINER SIEVE PERCENT FINER Material Description inches 0 O A number 0 ❑ 1�k O Poorly graded sand with silt and gravel 1 100.0 100.0 #4 70.9 69.7 82.0 .75 96.3 95.7 100.0 #10 59.1 58.6 74.9 0 Poorly graded sand with silt and gravel .5 91.3 90.2 91.9 #20 50.4 49.2 68.7 .375 85.1 83.5 89.8 #40 40.1 37.6 60.6 #60 25.6 23.2 48.4 Silty sand with gravel #140 12.1 10.3 33.1 #200 9.6 7.8 28.6 GRAIN SIZE REMARKS: D60 2.1701 2.2753 0.4123 O ASTM D-422 D30 0.2936 0.3212 0.0839 D10 0.0801 0.1026 0 ASTM D-422 COEFFICIENTS Cc 0.50 0.44 A ASTM D-422 Cu 27.09 1 22.18 O Source of Sample. TP-1 Depth:2.0 Sample Number:S-1 o Source of Sample:TP-1 Depth:5.5 Sample Number:S-2 o Source of Sample:TP-2 Depth:9.0 Sample Number:S-1 Phoenix Soil Research Client: Alkai Consultants,LLC Project: Belfair Coffee ACL05-11-G 113 Kingston, WA Pro'ectNo.: PSR05-1-1204 Figure 1 — — — --- ------ -------------------- S 252438" E 169.oY I I Q TP 2 W o N � W Q TP-3 0) � I r Z O TP-1 I I I I C I -------- -----J S 28'15'29" E 169.24' CLIFTON LANE FIGURE 2 SITE PLAN Project Name: Belfair Staf Location: Belfair,Washin Project No.: ACL05-11-G1, Client: Starbucks Coffee i