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Specifications U6 2007 1 Fe% " 8, Uri ,Drivr; " • America's Tire - New Facility Tigard, Oregon 5c(--2 - (20:52a City of Tigard A !roved Plans B 4bk Date L.40_ C.? t Gutech Solutions Incl July 17, 2007 GSI Project: americastire-07-0 I -gi OFFICE COPY U e c solutions I ncl July 17, 2007 americastire- 07 -01 -gi Discount Tire Co. 5310 E. Shea Blvd. Scottsdale, AZ 85254 -4700 dannwright@discounttireco.com Attention: Dan Wainwright GEOTECHNICAL ENGINEERING REPORT Highway 99 and SW 68th Parkway - Tigard, Oregon INTRODUCTION We appreciate the opportunity to present this Geotechnical Engineering Report for proposed facility in Tigard, Oregon. A geotechnical report for the project was completed by The Riley Group, Inc. of Bothel, Washington on March 18, 2006. In order for Geotech Solutions, Inc. to act as geotechnical engineer of record and provide services during construction, it was necessary to complete additional explorations at the site and provide a report for the project. The previous report and explorations were used to supplement our work. Based on a review of the site and grading plans grading for the new building will require cuts of approximately 6 feet and fills of up to 5 feet. Fills of 10 to 14 feet will be retained by a modular block retaining wall planned along the south side of the site to retain the new parking area. Building loads are expected to be less than 100 kips for columns, 6 kips per foot for walls, and 500 psf for floors. PURPOSE AND SCOPE The purpose of our services was to review the previous geotechnical report, complete site explorations, and provide an updated report allowing us to act as the geotechnical engineer of record through the duration of the project. Our specific scope of services included the following: • Provide senior level project management including management of field and subcontracted services, report writing, analyses, and invoicing. > Review previous reports, geologic maps and vicinity geotechnical information in our files as indicators of subsurface conditions. • Complete "One Call" public utility notification. The owner is responsible for locating private on -site utilities. • Explore subsurface conditions by excavating 3 test pits to depths of up to I I feet or refusal. ✓ Classify and sample the materials encountered and maintain a detailed log of the explorations. • Determine the moisture content of selected samples obtained from the explorations, and conduct soil classification testing as necessary. • Complete a qualitative evaluation of site stability in regard to planned development. > Provide recommendations for earthwork including seasonal material usage, use of granular working pads, cut and fill slope inclinations, and fill preparation and compaction. r103 3111 0 1/7 1112 7 Street, Oregon City, OR 97045 p 503.657.3487 f 503.722.9946 July 17, 2007 americastire- 07 -0I -gi P. Provide recommendations for foundation support, including suitable soils, bearing pressures, sliding coefficient, seismic coefficient, and construction considerations. • Provide recommendations for slab support, including a subgrade modulus, underslab rock thickness, materials, and preparation. • Provide recommendations for cantilevered concrete retaining walls and /or embedded building walls, including lateral earth pressures, sliding coefficient, drainage, and backfill materials and compaction. • Provide recommendations for pavements including subgrade preparation and stabilization, base rock and asphalt concrete thickness. ✓ Provide a written report summarizing the results of our geotechnical evaluation. GEOLOGIC MAP REVIEW A review of geologic maps of the site (GMS -59, GMS -9I) indicates the site is underlain by Pliocene to Pleistocene Boring Lava (QTb). The subsurface soil at the site, as observed in our explorations, are highly weathered and highly fractured with generally gravel- to cobble -sized basalt fragments within a silt/clay matrix and occasional large boulders. SITE OBSERVATIONS AND CONDITIONS Surface Conditions The approximate 5.3 -acre site is located along the south side of Pacific Highway, just west of I -5 in Tigard, Oregon. The site is bordered on the north by Pacific Highway, on the east by a gas station and undeveloped property, on the south by the Howard Johnson Motel, and on the west by paved parking and an undeveloped grass field. The site slopes gently down to the south at approximately 8H: I V, with an approximate 10 feet high 2H: I V slope along the southern perimeter of the property. The site is currently undeveloped and covered with short grass. Several trees are present along the crest of the southern slope. 'Subsurface Conditions General - The site was explored on June 20, 2007, by excavating three test pits (TP- I through TP -3) to depths of up to 11.0 feet at the approximate locations shown on the attached Site Plan. Subsurface conditions observed consisted of up to 12 inches of silt topsoil, underlain by silt and clay with variable amounts of gravel -sized basalt fragments. A large boulder was encountered at a depth of 2.5 feet in test pit TP -2. Several boulders were observed at the ground surface in several areas of the site. The observed soils are consistent with those identified by previous explorations at the site. Groundwater - Slow groundwater seepage was observed in test pit TP -2 at a depth of 5 feet bgs and moderate seepage from 7.0 to 9.5 feet during our explorations. Similarly, the Riley Group observed groundwater seepage in six of their eight test pits generally below depths of 6.0 to 8.5 feet bgs, with additional shallow seepage in three of their explorations at depths of 2.5 to 3.5 feet bgs. Perched ground water is expected to rise within a few feet of the surface during wet conditions. CONCLUSIONS AND RECOMMENDATIONS General Based on our observations and testing, construction of the proposed project is feasible following the recommendations contained herein. Site soils consist of silt and clay which is easily disturbed when wet. If construction is planned for wet conditions, measures should be taken to minimize disturbance. 2/7 1112 7 Street, Oregon City, OR 97045 p 503.657.3487 f 503.722.9946 - July 17, 2007 americastire- 07 -01 -gi Slope Stability We completed slope stability analyses using the computer program XSTABL to evaluate the relative effects of site grading in conjunction with planned retaining walls on overall site stability. The factor of safety for site slope stability (following grading and wall construction) for a cross - section through the middle of the site was greater than 1.5. • Earthwork Preparation - Prior to earthwork construction, the site should be prepared by completely removing existing structures, foundations, utilities, debris, and any uncontrolled fill. Site preparation for earthwork will also require removal of the root zone and topsoil from all pavement, building, and fill areas, and a 5 -foot perimeter around those areas. Any excavation resulting from the aforementioned preparation should be brought back to grade with structural fill. Disturbed surficial fill mixed with debris was observed at the ground surface in the vicinity of the demolished structures and should be removed. The heavy root zone encountered in our exploration ranged in thickness from 2 to 6 inches. Thicker stripping depths may be necessary in areas of tall grass, weeds, and brush. The thickness of the topsoil /rootzone observed in our explorations was between 12 and 24 inches. We should be contacted to evaluate site preparation including removal of the existing undocumented fill and topsoil during earthwork construction. The topsoil layer should be completely removed from building areas regardless of weather conditions or construction season. Root balls from trees may extend several feet and grubbing operations can cause considerable subgrade disturbance. All disturbed material should be removed to undisturbed subgrade and backfilled with structural fill. In general, roots greater than one -inch in diameter should be removed. The test pit excavations were backfilled using relatively minimal compactive effort and soft spots can be expected at these locations. We recommend that these relatively uncompacted soils be removed from the test pits located within the proposed building and paved areas to a depth of 3.0 feet below finished subgrade. The resulting excavation should be brought back to grade with structural fill. If located beneath a footing, the uncompacted soils should be completely removed and replaced with structural fill. Stabilization and Soft Areas - After stripping, we should be contacted to evaluate the exposed subgrade. This evaluation can be done by proof rolling in dry conditions or probing during wet conditions. Soft areas will require overexcavation and backfilling with well graded, angular crushed rock compacted as structural fill. A geosynthetic may also be required. We recommend that a geosynthetic used for stabilization consist of a woven geosynthetic with an AOS of #70 to #100 sieve, and a minimum puncture resistance of 120 pounds (such as an AMOCO 2019 or equivalent). Working Blankets and Haul Roads - Construction equipment should not operate directly on the subgrade when wet, as it is susceptible to disturbance and softening. Rock working blankets and haul roads placed over a geosynthetic in a thickened advancing pad can be used to protect subgrades. We recommend that sound, angular, pit run or crushed basalt with no more than 6 percent passing a #200 sieve be used to construct haul roads and working blankets. Working blankets .should be at least 12 inches thick, and haul roads at least 24 inches thick. Alternatively, the soils could be cement amended 3/7 1112 7 Street, Oregon City, OR 97045 p 503.657.3487 f 503.722.9946 July 17, 2007 americastire- 07 -01 -gi to a depth of 12 inches and covered with 4 inches of crushed rock. Some repair of working blankets and haul roads should be expected. The above rock thicknesses are the minimum recommended. Subgrade protection is the responsibility of the contractor and thicker sections may be required based on subgrade conditions and type and frequency of construction equipment. Fill - Due to the clay content, small site, and presence of boulders, reuse of the on -site soil as structural fill will be difficult. It may be possible to use the on -site soil as structural fill during dry summer grading but will require proper moisture conditioning before it can be used for structural fill. This is not feasible during wet conditions. In dry summer conditions the soils will require drying by discing in thin lifts and frequently turning the materials. Once moisture contents are within 3 percent of optimum, compaction should take place with a tamping foot type compactor and reach 92 percent relative to ASTM D 1557 (modified proctor). Fill should be placed in lifts no greater than 10 inches in loose thickness. In addition to meeting density specifications, fill will also need to pass a proof roll using a loaded dump truck, water truck, or similar size equipment. In wet conditions, fill should be imported granular soil with less than 6 percent fines, such as clean crushed or pit run rock. Pulverized AC pavement and silty base rock can be used as structural fill provided it is prepared as recommended for granular soils. Due to the amount of silt, we don't recommend using this material as pavement base rock. Granular fill should also be compacted to 95 percent relative to ASTM D 1557. Trenches - Utility trenches may encounter ground water seepage. Caving is expected where seepage is encountered. Shoring of utility trenches will be required for depths greater than 4 feet. Groundwater seepage, if encountered, can likely be accommodated with sump pumps. Stabilization of the base of trenches with at least 12 inches of clean, angular pit run rock may be necessary where seepage is present. Pipe bedding should be installed in accordance with the pipe manufacturers' recommendations. Trench backfill above the pipe zone should consist of well graded, angular crushed rock with no more than 7 percent passing a #200 sieve. Trench backfill should be compacted to 92 percent relative to ASTM D 1557, and paving should not occur within one week of backfilling. Shallow Foundations Footings should be embedded at least 18 inches below the lowest adjacent, exterior grade. Footings can be designed for an allowable bearing pressure of 2,500 psf for stiff or better native silt. The preceding bearing pressure can be increased to 5,000 psf for temporary wind and seismic loads. Continuous footings should be no less than 18 inches wide, and pad footings should be no less than 24 inches wide. Resistance to lateral loads can be obtained by a passive equivalent fluid pressure of 350 pcf against suitable footings, ignoring the top 12 inches of embedment, and by a footing base friction coefficient of 0.35. Properly founded footings are expected to settle less than a total of I inch, with less than 1/2 inch differentially. Installation of the roofing and other significant building loads prior to installation of settlement sensitive materials (such as dry wall, tile, and tiled or planked flooring) can reduce settlement impacts. Primary settlement is expected to be complete within a week of building load applications, and additional settlement often occurs during the first few wet seasons. 4/7 11 12 7t Street, Oregon City, OR 97045 p 503.657.3487 f 503.722.9946 July 17, 2007 americastire- 07 -01 -gi If construction is to occur in wet conditions, a few inches of crushed rock should be placed at the base of footing excavation to reduce subgrade disturbance and softening during construction. Slabs Floor slab loads of less than 500 psf are expected to induce less than one inch of settlement. A minimum of six inches of clean, angular crushed rock with no more than 5 percent passing a #200 sieve is recommended for underslab rock. Prior to slab rock placement the subgrade will need to be evaluated by us by probing or will need to pass a proof roll with a fully loaded truck. Underslab rock should be compacted to 92 percent compaction relative to ASTM D 1557, and should be proof rolled as well. In addition, any areas contaminated with fines must be removed and replaced with clean rock. If the base rock is saturated or trapping water, this water must be removed prior to slab placement. Embedded Building Walls and Cast -in -Place Retaining Walls General - The following recommendations are based on the assumptions that (I) Wall backfill consists of level, well- drained, angular, granular material, (2) Walls are less than 10 feet in height, and (3) No surcharges such as stockpiled soil or equipment is placed within 10 feet of the wall. Design - Walls restrained against rotation, such as embedded building walls (braced before backfilling), should be designed using an equivalent fluid pressure of 55 pcf. Walls not restrained against rotation (backfilled prior to bracing) should be designed using an equivalent fluid pressure of 34 pcf. For embedded building walls with a daylight basement configuration, a superimposed seismic lateral force equivalent to 9.4H pounds (where H is the total wall height in feet) should be applied at a height of 0.6H above the base of the wall footing. These forces can be resisted by passive pressure at the toe of the wall using an equivalent fluid pressure of 350 pcf (this should exclude the top 12 inches of embedment) and friction along the base using a friction coefficient of 0.35. Wall pressures associated with surcharges located within 10 feet of the wall should be calculated as 0.3P (where P is the surcharge pressure along the ground surface at the top of the wall in psf). The resulting additional surcharge wall pressure should be a rectangular distribution. Backfill - Retaining walls should be backfilled with clean, imported, granular soil with less than 6 percent fines, such as clean sand or rock. This material should also be compacted to a minimum of 92 percent relative to ASTM D 1557 (modified proctor). Within 3 feet of the wall, backfill should be compacted to not more than 90 percent relative to ASTM D 1557 using hand - operated equipment. Drainage - Although no groundwater seepage was observed during our explorations, seasonal seepage and /or perched groundwater should be anticipated. Ground surfaces and hardscaping should be sloped to drain away from the building. Wall drains should consist of a two -foot wide zone of drain rock encompassing a 4 -inch diameter perforated pipe, all enclosed with a nonwoven filter fabric. The drain rock should have no more than 2 percent passing a #200 sieve and should extend to within one foot of the ground surface. The geosynthetic should have an AOS of a #70 sieve, a minimum permittivity of 1.0 sec-', and a minimum puncture resistance of 80 pounds (such as an AMOCO 4551 or equivalent). One foot of low permeability soil (such as the on -site silt) should be placed over the fabric at the top of the drain to isolate the drain from surface runoff. Alternatively, a composite drain board, can be substituted for the chimney of drain rock. 5/7 1 1 12 7 Street, Oregon City, OR 97045 p 503.657.3487 f 503.722.9946 • n July 17, 2007 americastire-07-0 1 -gi Ground Moisture General - If footing construction is to occur in wet conditions, a few inches of crushed rock should be placed at the base of footings to reduce subgrade disturbance and softening during construction. The surface at the building perimeter should be sloped to drain away from the building. Perimeter Foundation Drains - Perimeter foundation drains are required around all exterior foundations. The foundation drains should consist of a two -foot wide zone of drain rock encompassing a 4 -inch diameter perforated pipe, all enclosed with a non -woven filter fabric. The drain rock should have no more than 2 percent passing a #200 sieve and should extend to within one foot of the ground surface. The geosynthetic should have an AOS of a #70 sieve, a minimum permittivity of 1.0 sec and a minimum puncture resistance of 80 pounds (such as an AMOCO 4551 or equivalent). One foot of low permeability soil (such as the on -site silt) should be placed over the fabric at the top of the drain to isolate the drain from surface runoff. Foundation drains must be routed to a suitable discharge. Vapor Flow Barrier - Where moisture sensitive floor coverings, such as tile or adhesive flooring, will be installed, a continuous, impervious barrier must be installed beneath the slab over the ground surface. Barriers should be installed per the manufacturer's recommendations. Pavement Asphalt Concrete - We have developed asphalt concrete pavement thickness at the site for 5, 10, and 25 trucks per day and a 20 -year design life. These volumes can be revised if specific traffic data is available. Our analyses is based on AASHTO methods and subgrade of structural fill or undisturbed medium stiff or better native silt having a resilient modulus of 6,000 psi. We have also assumed that roadway construction will be completed during an extended period of dry weather. The results of our analyses based on these parameters are provided in the table below. Trucks ESAL's AC (inches) CR (inches) 5 32542 3 7 10 65084 3 9 25 162711 4 8 The thicknesses listed in the table above are intended to be the minimum acceptable. Crushed rock should conform to ODOT base rock standards and have less than 6 percent passing the #200 sieve. Asphalt concrete should be compacted in lifts no greater than 3 inches in thickness to 91 percent of a Rice Density, or to 98 percent of the maximum density from a test strip. Portland Cement Concrete - Dock aprons of portland cement concrete should be a minimum of 7 inches thick for up to 25 trucks per day, and should be underlain by at least 6 inches of crushed rock base over approved subgrade. We recommend load transfer devices /dowels at the joints. Seismic Design General - In accordance with the International Building Code (IBC) 2003 as adopted by the State of Oregon Structural Specialty Code (SOSSC), the subject project should be evaluated using the parameters associated with Site Class D. 6/7 1 1 12 7 Street, Oregon City, OR 97045 p 503.657.3487 f 503.722.9946 July 17, 2007 americastire- 07 -01 -gi Liquefaction - Liquefaction occurs in loose, saturated, granular soils. Strong shaking, such as that experienced during earthquakes, causes the densification and the subsequent settlement of these soils. Given the soil type and consistency encountered in our explorations, the risk of structurally damaging liquefaction is low. LIMITATIONS AND OBSERVATION DURING CONSTRUCTION We have prepared this report for use by Discount Tire Co. and their design and construction teams for this project only. The information herein could be used for bidding or estimating purposes but should not be construed as a warranty of subsurface conditions. We have made observations only at the aforementioned locations and only to the stated depths. These observations do not reflect soil types, strata thicknesses, water levels or seepage that may exist between observations. We should be consulted to observe all foundation bearing surfaces, proof rolling of slab and pavement subgrades, installation of structural fill, and any cut slopes. We should be consulted to review final design and specifications in order to see that our recommendations are suitably followed. If any changes are made to the anticipated locations, loads, configurations, or construction timing, our recommendations may not be applicable, and we should be consulted. The preceding recommendations should be considered preliminary, as actual soil conditions may vary. In order for our recommendations to be final, we must be retained to observe actual subsurface conditions encountered. Our observations will allow us to interpret actual conditions and adapt our recommendations if needed. Within the limitations of scope, schedule and budget, our services have been executed in accordance with the generally accepted practices in this area at the time this report was prepared. No warranty, expressed or implied, is given. < > We appreciate the opportunity to work with you on this project and look forward to our continued involvement. Please call if you have any questions. c P ROFF - 0 Sincerely, V S� �� G t N 4. O j4 (.7 53660PE v ORBGON �1r Ryan White, MS, PE, GE gAY ,6 e� Senior Project Engineer '9 �, r AN WN\� `RENEWAL DATE: 1e isnek ,1 Don Rondema, MS, PE, GE Principal Attachments — Site Plan, Test pit logs, Moistures cc: Craig Harris, AAI Engineering, craigh @aaieng.com 7/7 1112 7'" Street, Oregon City, OR 97045 p 503.657.3487 f 503.722.9946 ....- - ...----•-•--------------- .../ ...--- .../..------.... ...--' ----- \ ..-•'''''.---- \‘' ''''' / .......- ---- --- .., A \A\ ---- ,*- ---ii - sr- 00 ...--- ; , , 0 ...-- _-,-.. ....,..,' ...-- --e" .....,,.., s` ..... \ A - \ ---, ...------- 1111M - -- ,, 36, , ,_ \ v - \ \ 77 1 • 1 •. \ t , • . , -- - -.Adak • 6 N \ \ \ „------------ \ - .2 • • I ..-•- , \ • \ " • • TP-I . — 1 ,, .. , .... \ \ \ .., .,,.._..._.,..•,,„,___,—"„,-- -., 5, • I - ..--.. • I N I , „, ....' ii ....„ ......, ....., _..., . -, - -- • 1 ....- .,.-- -...„ ......, ......, - ' — - • .. , 0 s., -- — — I ,..... ,„----- ---- 14 — . ....- , - ,..._ __ ....• .1/2—.... i .. • 1 ,.... : - - o 0 ,...,_ _ 1.- ‘., \ ..,.... , .,...• , I" _ 00, .::■;, ...;....„.. . _ ......_ iip. .... „ ... _ M 0 . ..r"' -.--- • . • —I PROPOSED - • - — --; .k — — - 0 .1■ • - -- - s \ r --\ III • TP-2 .. E - --'s5.50 - • -- -- . TP-7 — AI 1 TP-3 ' ___ .. __, \ 1' Il — ' . — ' - -I — .1— I -1 ///7/ ,. to. . ......... % . . k —.,. __ ■___..,-- •—_ i s. .. .. -- — --". TP 8 1 - 1 ‘ - — ... TP-6 . ._ ._. ),.-- .., —. ..... , --- • - -. - — — ,..//1/1/4 ....-- — - - - . • - - - - ., ,...,--- — —.-= — \ ..--' .-- -.:.-'• 1 I . , _ _ ,ll \ I 01 , 1 i • _ . ,... , ___ ___ _ _ _ --,..,,,_ 4- 1,......& .. , _ , __ .....,. IIII ._. ...... • ......_ _,- -_ . TP-I ...._ • ---'-- 1 • , .,.....50— . . • :),, , --- - TP-3 — — ---___ ff, • --- N i ___ ____ ______ - — ..... _ ":,, 1 -- 1x .151 _ ...._ ___ -- --1 • 1 TP-5 • — -- — -- — I • 41 -- --- ll N 1 — — --.. lit_ I - _ ____ N _ ,.... ..,....\_....._. . _ ,...1 „!, \ _ __ _::---..---._ -_ -- --__--__ _--._-f•r: --_-_-_ .,,.:-.- - ---, .........= - I •••••"" . __ ___ ___ ___ ___ ___ --_ ___ --- --._ N. - j •••••' -- --Z..- - - ....._ -...., --- - - -.....„ ---- I , i ---- --- ------- --7 -- -- --- - " ---- I ••••"- „, N. / \ \ / N ----- _____ ____ --- 34 - --_ -__ --- .,P I ...., .., . \ \ \. , . ..„ ..,___ ......._____,... — 1. ,-- \_i _____ \ / ...„ \ , , \ \ \ x ,,,,. ...._ /, ...._ 7 ...- ..„ \ \ \ \ , \., , // .... \ ‘ ■ / , „ 7 _ , z GEOTECH SOLUTIONS, INC (2007) / / / THE RILEY GROUP, INC. (2006) Z\ .-- ) / \ \ /1. ' ' 1 \i\-- 1/ . / 1 / . ' . . I inch = 50 feet BASE DRAWING PROVIDED BY AAI ENGINEERING G e_p SITE PLAN soYalons Incl americastire-07-0 I -gi Test Pit # Depth (ft) Soil Description Test pit explorations completed on June 20, 2007 with a John Deere 310E backhoe (approx. 15,000 Ib). TP- I Location: SW corner of proposed buidlling. Surface conditions: grass. 0 - 0.7 Medium stiff, dark brown SILT with trace fine organics (topsoil); moist. 0.7 - 1 1.0 Very stiff to hard, red -brown and brown SILT with some clay and trace to some, gravel -sized basalt fragments; moist. • No seepage or caving observed. TP -2 Location: Middle of proposed building. Surface conditions: Silt and weeds. 0 - 1.0 Stiff, dark brown SILT with trace fine organics (topsoil); moist. 1.0 - 3.5 Medium stiff to stiff, brown SILT with trace fine sand; moist. 2.5 - 4.5 -ft diameter boulder encountered. 3.5 - 1 1.0 Medium stiff, brown SILT with some clay and trace to some, gravel -sized basalt fragments; moist to wet. 6.5 - becomes stiff and red - brown. Slow seepage at 5 feet. Slow to moderate seepage from 7 to 9.5 feet. No caving observed. TP -3 Location: SE corner of proposed parking area. Surface conditions: Tilled silt. 0 - 0.8 Stiff, dark brown SILT with trace fine organics (topsoil); moist. 0.8 - 10.5 Very stiff, red -brown SILT with trace to some clay and occasional to trace, gravel - sized basalt fragments; moist. No seepage or caving observed. ch TEST PIT LOGS G o IU l I o n s I n c l americastire-07-0 I -gi Test Pit Depth, ft Moisture Content TP -1 2.0 26% TP -1 5.0 40% • TP -2 2.0 28% TP -2 4.0 34% TP -2 7.0 49% TP -3 2.0 25% TP -3 4.0 26% TP -3 7.0 30% TP -3 10.0 56% • • 6 L,Qt� C� MOISTURE CONTENTS So I ncl americastire- 07 -01-gi Ge tEEcJ� solutions Incl SITE VISIT REPORT: Discount Tire - Tigard, Oregon americastire- 07- 01-cros To: Dan Wainwright, Discount Tire Co., dwainwright @discounttireco.com Visit Date: July I, 2008 Arrival Time: 9:00 am Permit #: N/A Weather: 60 ° , sunny Subject: Retaining Wall Backfill Preparation. I arrived on site as requested by Norm of Bones Construction (Bones) to observe preparation of the backfill for the retaining wall along the entry drive located on the east side of the site. I met with Norm, Randy of Bones, and Reg Morris of Baker Construction on -site. When I arrived, I observed that the wall, which ranges from approximately 1.5 to 5.0 in height, had been backfilled with an initial lift of approximately 12 inches. Backfill consisted of a mixture of clean, 4 -inch minus and 3 /4 -inch minus crushed rock. The width of the backfill was approximately 3 to 5 feet. The rock was being compacted using a jumping jack and multiple passes until the rock was well keyed. Approximately 6 to 12 inches of silt topsoil is planned behind the wall and will be separated from the backfill with geotextile fabric. Based on our observations, aforementioned wall backfill is being prepared in general accordance with the intent of our recommendations. We will return to the site as contacted. Ryanhite, MS, PE, GE Senior Project Engineer cc: Kathy Peters, Discount Tire Co., kpeters @discounttireco.com Dana Korns, Discount Tire Co., dkorns @discounttireco.com Steve Beiser, Discount Tire Co., Steve.Beiser @discounttireco.com Reg Morris, Baker Construction, rmorris @bakerconstruct.com Todd Harnetiaux, Baker Construction, toddh @bakerconstruct.com Mike Dennis, Bones Construction, mike @bonesco.com Craig Harris, AAI Engineering, craigh @aaieng.com This report presents opinions formed as a result of our observation of activities relating to geotechnical engineering services. We rely on the contractor to comply with the plans and specifications throughout the duration of the project irrespective of the presence of our representative. Our work does not include quality control, and contractors and subcontractors have no right to rely on our services and reports. Our work does not include supervision or direction of the contractor, the contractor's employees, or agents. Our firm is not responsible for site safety. I/I 1 1 12 7`" Street, Oregon City, OR 97045 p 503.657.3487 f 503.722.9946 • G eSo utions Inc SITE VISIT REPORT: Discount Tire - Tigard, Oregon americastire- 07- 0I-cros To: Dan Wainwright, Discount Tire Co., dwainwright @discounttireco.com Visit Date: July 7, 2008 Arrival Time: 8:00 am Permit #: N/A Weather: 65 °, sunny Subject: Proofroll of Pavement Area Base Rock. I arrived on site as requested by Reg Morris of Baker Construction to observe a proofroll of the pavement area base rock. I met with Reg and Norm of Bones Construction on -site. Paving was scheduled to begin at 8. When I arrived on -site I observed Bones finish grading the base rock at the entrance to the services bays and near the site entrance: The first asphalt truck (dual, tandem) was used for a proofroll of the parking area drive aisles and accessible pull -in parking areas. In general, no noticeable deflection was observed under the truck tires. The surface of the base rock was loose and dry. I recommended wetting and recompacting these areas prior to paving. Reg stated that water was not available. I observed the pavers rolling the loose areas prior to paving. ' Based on our observations, the aforementioned base rock was prepared in general accordance with the intent of the specifications. We will return to the site as contacted. Ryan kite, MS, PE, GE Senior Project Engineer cc: Kathy Peters, Discount Tire Co., kpeters @discounttireco.com Dana Korns, Discount Tire Co., dkorns @discounttireco.com Steve Beiser, Discount Tire Co., Steve.Beiser @discounttireco.com Reg Morris, Baker Construction, rmorris @bakerconstruct.com Todd Harnetiaux, Baker Construction, toddh @bakerconstruct.com Mike Dennis, Bones Construction, mike @bonesco.com Craig Harris, AAI Engineering, craigh @aaieng.com This report presents opinions formed as a result of our observation of activities relating to geotechnical engineering services. We rely on the contractor to comply with the plans and specifications throughout the duration of the project irrespective of the presence of our representative. Our work does not include quality control, and contractors and subcontractors have no right to rely on our services and reports. Our work does not include supervision or direction of the contractor, the contractor's employees, or agents. Our firm is not responsible for site safety. I/I 1 1 12 7` Street, Oregon City, OR 97045 p 503.657.3487 f 503.722.9946 • ex t E h Solutions Inc' SITE VISIT REPORT: Discount Tire - Tigard, Oregon americastire- 07- 0 I - cros To: Dan Wainwright, Discount Tire Co., dwainwright @discounttireco.com Visit Date: July 7, 2008 Arrival Time: 10:00 am Permit #: N/A Weather: 60 ° , sunny Subject: Complete Density Testing for Asphalt Concrete Pavement. I arrived on site as requested by Reg Morris of Baker Construction to complete density testing on the asphalt concrete (AC) pavement for the new parking area. I met with Reg and Norm of Bones Construction on -site. The paving contractor was Kodiak Pacific (KP). The KP supervisor provided a maximum rice density of 153.8 pcf from the pit for the C -mix being used. Density testing was completed using a Troxler nuclear densometer. The thickness of the AC was 3 inches for pull -in parking and 4 inches for drive aisles. Density testing was completed in each panel throughout paving following compaction. Compaction was being completed almost continuously using two smooth -drum vibratory rollers. The entrance was the last area paved and was too hot to test during our visit. Resulting densities ranged from 91 to 94 percent with an average greater than 92 percent, which exceeds the recommended 92 percent. We will return to the site as contacted. Rya kite, MS, PE, GE Senior Project Engineer cc: Kathy Peters, Discount Tire Co., kpeters @discounttireco.com Dana Korns, Discount Tire Co., dkorns @discounttireco.com Steve Beiser, Discount Tire Co., Steve.Beiser @discounttireco.com Reg Morris, Baker Construction, rmorris @bakerconstruct.com Todd Harnetiaux, Baker Construction, toddh @bakerconstruct.com Mike Dennis, Bones Construction, mike @bonesco.com Craig Harris, AAI Engineering, craigh @aaieng.com This report presents opinions formed as a result of our observation of activities relating to geotechnical engineering services. We rely on the contractor to comply with the plans and specifications throughout the duration of the project irrespective of the presence of our representative. Our work does not include quality control, and contractors and subcontractors have no right to rely on our services and reports. Our work does not include supervision or direction of the contractor, the contractor's employees, or agents. Our firm is not responsible for site safety. 1/I 1 1 12 7`" Street, Oregon City, OR 97045 p 503.657.3487 f 503.722.9946