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HomeMy WebLinkAboutEngineering Report 02.27.2015Grtech HEPWORTH-PAWLAK GEOTECHNICAL Hepworth-Pawlak Geotechnical, Inc. 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 Email: hpgeo@hpgeotech.com GEOTECHNICAL ENGINEERING STUDY PROPOSED FEDEX GROUND SORT FACILITY COUNTY ROAD 154 NEAR STATE HIGHWAY 82 GARFIELD COUNTY, COLORADO JOB NO. 115 023A FEBRUARY 27, 2015 PREPARED FOR: KW GLENWOOD SPRINGS, LLC ATTN: KEVIN KIERNAN 941 ORANGE AVENUE, #512 CORONADO, CALIFORNIA 92118 ke%in,a thei:iernancompanies.com TABLE OF CONTENTS PURPOSE AND SCOPE OF STUDY - I - PROPOSED CONSTRUCTION - I - SITE CONDITIONS - 2 - SUBSIDENCE POTENTIAL AND GEOLOGIC CONDITIONS - FIELD EXPLORATION - 3 - SUBSURFACE CONDITIONS - 4 - FOUNDATION BEARING CONDITIONS__ ..... ..... ...... ......... ...... 5 - DESIGN RECOMMENDATIONS - 5 - FOUNDATIONS .......... . .. . ..... ... .... ________ ... . ............. 5 - FOUNDATION AND RETAINING WALLS ..... - ... ... ......... - 7 - FLOOR SLABS - 8 . UNDERDRAIN SYSTEM . .. ......... .. ............ _ ... ..... ....... 8 - SITE GRADING - 9 - PAVEMENT SECTION ... . ..... .... . .. ... . . ............. MM••••.3 ..... 9 - SURFACE DRAINAGE lo. LIMITATIONS - I I - FIGURE 1 - LOCATION OF EXPLORATORY BORINGS AND PITS FIGURES 2 AND 3- LOGS OF EXPLORATORY BORINGS FIGURE 4- LEGEND AND NOTES -EXPLORATORY BORINGS FIGURE 5 - LOGS OF EXPLORATORY PITS FIGURES 6 AND 7 SWELL -CONSOLIDATION TEST RESULTS FIGURES 8 TI IROUGI - GRADATION TEST RESULTS FIGURE 11 - USDA GRADATION TEST RESULTS TABLE I - SUMMARY OF LABORATORY TEST RESULTS TABLE 2- PERCOLATION TEST RESULTS Job No. 115 023A GJtech PURPOSE AND SCOPE OF STUDY This report presents the results of a geotechnical engineering study for the proposed FedEx Ground Sort Facility to be located at County Road 154 near State Highway 82, Garfield County, Colorado. The project site is shown on Figure 1. The purpose of the study was to develop recommendations for the foundation, grading and pavement designs. The study was conducted in accordance with our proposal for geotechnical engineering services to KW Glenwood Springs, LLC dated January 15, 2015. A field exploration program consisting of exploratory borings and pits was conducted to obtain information on the subsurface conditions. Samples of the subsoils obtained during the field exploration were tested in the laboratory to determine their classification, compressibility or swell and other engineering characteristics. The results of the field exploration and laboratory testing were analyzed to develop recommendations for foundation types, depths and allowable pressures for the proposed building foundation, site grading and pavement sections. This report summarizes the data obtained during this study and presents our conclusions, design recommendations and other geotechnical engineering considerations based on the proposed construction and the subsurface conditions encountered. PROPOSED CONSTRUCTION The proposed building will be a single story structure with office and package sorting areas and slab -on -grade floor. The building will be surrounded by drives and parking that will be asphalt paved. The depressed dock will be located at the northeast side of the building and the ramp paved with concrete. Grading for the structure and surrounding paved surfaced areas will typically have shallow cut and fill grading up to about 4 to 5 feet deep. We assume relatively light continuous wall and moderate column foundation loadings, typical of the proposed type of construction. An individual septic disposal system is proposed for onsite sewage disposal. A 20,000 gallon steel water storage tank will be provided at the uphill, east side of the property. The overall layout of the proposed facilities is shown on Figure 1. Join No. 115 023A GeZtech -2 - If building loadings, location or grading plans change significantly from those described above, we should be notified to re-evaluate the recommendations contained in this report. SITE CONDITIONS The proposed development is located just southwest of County Road 154 (Old State Highway 82) near the intersection with State Highway 82 and mostly consists of a vacant, irrigated pasture. A gravel ranch road crosses the west end of the property. The ground surface slopes moderately down from CR 154 then flattens to nearly level through the proposed building site then moderately before sloping steeply down to the Roaring Fork River off the property to the south. InterMountain Waste & Recycling is located immediately south (and will be the entrance) of the project site, irrigated field is located to the north and sage covered, non -irrigated land is located to the west. Vegetation consists mostly of grass and weeds on the project site except for the west end where there is sage brush. There was 6 to 8 inches of snow on the site at the time of drilling. SUBSIDENCE POTENTIAL AND GEOLOGIC CONDITIONS Bedrock of the Pennsylvanian age Eagle Valley Formation underlies the project site. These rocks are a sequence of shale, fine-grained sandstone and siltstone and can contain beds or inclusions of gypsum which is in turn underlain by Eagle Valley Evaporite which can contain massive beds of gypsum. There is a possibility that massive gypsum deposits associated with the Eagle Valley Evaporite underlie portions of the property. Dissolution of the gypsum under certain conditions can cause sinkholes to develop and can produce areas of localized subsidence. During previous studies in the area, several sinkholes have been observed scattered throughout the Roaring Fork River valley which appear similar to others associated with the Eagle Valley Evaporite. Sinkholes were not observed in the immediate area of the project site. No evidence of cavities was encountered in the subsurface materials; however, the exploratory borings were relatively shallow, for foundation design only. Based on our present knowledge of the subsurface conditions at the site, it cannot be said for certain that sinkholes will not develop. The risk of future ground subsidence on the project site throughout the service Job No, 115 023A H&tech -3 - life of the proposed facilities, in our opinion, is low; however, the owner should be made aware of the potential for sinkhole development. If further investigation of possible cavities in the bedrock below the site is desired, we should be contacted. Red siltstone of the Maroon Formation is exposed to the northeast across State Highway 82. Grey to tan siltstone of the Eagle Valley Formation underlies the Maroon at roughly the bottom of river, on the order of 60 feet below the project site. The formation rock bedding is generally relatively flat lying below the project site to moderately dipping into the valley side northeast of the project site. At these bedding grades, the formation rock should be relatively stable against slope instability. The formation on the hillside is covered with relatively shallow colluvium with a thicker wedge of slope wash deposit along the toe of the hillside which State Highway 82 alignment roughly follows in the section above the project site. StnalI ephemeral drainages have developed which cut through the colluvial slope wash deposits and coalesce below State Highway 82 and CR 154 to form relatively fine-grained alluvial fan deposits on top of the river terrace deposits which underlie the project site and extend down to the Roaring Fork River. These river terrace deposits consist of clast supported gravel, cobbles and boulders in a silty sand matrix and in turn are underlain by bedrock of the Eagle Valley Formation. Based on our review, there are no significant geologic hazards that would make the project infeasible and their potential impacts can be mitigated with good engineering and construction practices. FIELD EXPLORATION The field exploration for the project was conducted between January 27 and February 24, 2015. Fourteen exploratory borings were drilled in the building and surrounding area and two profile pits and 4 percolation holes were dug in the proposed septic disposal area at the locations shown on Figure 1 to evaluate the subsurface conditions. The borings were advanced with 4 -inch diameter continuous flight augers powered by a CME -45B drill rig and the pits were dug with a rubber -tired backhoe. The borings and pits were logged by a representative of Hepworth-Pawlak Geotechnical, Inc. Job No. 115 023A Czech -4 - Samples of the subsoils were taken with 1% inch and 2 inch LD. spoon samplers in the boreholes and by disturbed methods in the pits. The samplers were driven into the subsoils at various depths with blows from a 140 pound hammer falling 30 inches. This test is similar to the standard penetration test described by ASTM Method D-1586. The penetration resistance values are an indication of the relative density or consistency of the subsoils. Depths at which the samples were taken and the penetration resistance values are shown on the Logs of Exploratory Borings, Figures 2, 3 and 5. The samples were returned to our Iaboratory for review by the project engineer and testing. SUBSURFACE CONDITIONS Graphic logs of the subsurface conditions encountered at the site are shown on Figures 2, 3 and 5. The subsoils, below about %Z foot of topsoil, consist of up to about 15 feet of sandy silt and silty clay in the central to eastern part and up to about 6 feet of silty sand with gravel in the western part, overlying dense, silty sandy gravel and cobbles with boulders. Drilling in the dense river gravel soils with auger equipment was difficult due to the cobbles and probable boulders and drilling refusal was encountered in the deposit. Laboratory testing performed on samples obtained from the borings included natural moisture content and density, gradation analyses, liquid and plastic limits and unconfined compressive strength. Results of swell -consolidation testing performed on relatively undisturbed drive samples of the silty clay soils, presented on Figures 6 and 7, indicate low to moderate compressibility under conditions of loading and wetting. Results of gradation analyses performed on small diameter drive samples (minus 1!.'i inch fraction) of the natural granular soils are shown on Figures 8 through 10. The Iiquid and plastic limits testing indicate the soils have low or no plasticity and the unconfined compressive strength tests indicate the silt and clay soils generally have medium stiff consistency. The laboratory testing is summarized in Table 1. No free water was encountered in the borings or pits. The granular soils were slightly moist and the silt and clay soils were very moist. The percolation test results are presented in Table 2 and indicate infiltration rates between 30 and 60 minutes per inch for the upper fine-grained soils. The results of a USDA gradation test performed on a sample of the silt taken at the proposed septic disposal area are presented on Figure 11. Job No. 115 023A Gecstech 5 FOUNDATION BEARING CONDITIONS The soils encountered across the project site are variable in type, depth and engineering properties. The silt and clay soils encountered in the middle to northeastern part of the site at shallow depth are compressible under loading but appear suitable for support of lightly loaded spread footings with low bearing capacity. The granular soils encountered near existing ground surface from roughly the middle of the building site and extending to the southwest have relatively low settlement potential with moderate bearing capacity. The silt and clay soils are also a poor subgrade for pavement section support. A coarse grained structural material should be used to improve the bearing capacity below footings and as a subbase layer below the pavement section in silt and clay soil areas. A deep foundation which extends down to the dense river gravel deposit could be used to achieve a low settlement risk foundation. Presented below are recommendations for shallow spread footings. If a deep foundation is considered for building support, we should be contacted for additional analysis and recommendations. DESIGN RECOMMENDATIONS FOUNDATIONS Considering the subsurface conditions encountered in the exploratory borings and the nature of the proposed construction, we recommend the building be founded with spread footings bearing on the compacted fill soils or natural granular soils. The design and construction criteria presented below should be observed for a spread footing foundation system. 1) Footings placed on compacted fill soils or the natural granular soils should be designed for an allowable bearing pressure of 2,000 psf. Based on experience, we expect settlement of footings designed and constructed as discussed in this section will be about 1 inch or less and could be differential due to the variable bearing conditions. There could be some additional differential settlement if the bearing soils become wet. Job No. 115 023A -6- 2) The footings should have a minimum width of 18 inches for continuous walls and 2 feet for isolated pads. 3) Exterior footings and footings beneath unheated areas should be provided with adequate soil cover above their bearing elevation for frost protection. Placement of foundations at least 36 inches below exterior grade is typically used in this area. 4) Continuous foundation walls should be reinforced top and bottom to span local anomalies such as by assuming an unsupported length of at least 12 feet. Foundation walls acting as retaining structures should also be designed to resist lateral earth pressures as discussed in the "Foundation and Retaining Walls" section of this report. 5) The topsoil, silt and clay soil to the prescribed depth and loose or disturbed soils should be removed and the footing bearing level extended down to firm soils. The exposed soils in footing area should then be moisture adjusted to near optimum and compacted. In silt and clay soil areas, the exposed soils should be sub -excavated to provide at least 2 feet of compacted structural fill, such as CDOT Class 2 base course or similar granular material, below footing bearing grade. Compaction should be to at least 98°O of standard Proctor density at near optimum moisture content. The structural fill should extend beyond the footing edges a distance of at least !°z the depth of fill below the footing. 6) The proposed water storage tank located between Borings 3 and 4 is expected to be cut into silt and clay soils. The subgrade below the water storage tank should be improved by placing at least 2 feet of structural fill similar to that described above in item 5 before placing base course material for the tank support. 7) Site Class C of IBC 2009, Table 1613.5.2 can be used in the seismic analysis of the structure. 8) A representative of the geotechnical engineer should observe all footing excavations prior to concrete placement to evaluate bearing conditions and test compaction of the structural fill. Job No. 115 023A GecDtech -7 - FOUNDATION AND RETAINING WALLS Foundation walls and retaining structures which are laterally supported and can be expected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at Ieast 55 pcf for backfill consisting of the on-site soils. Cantilevered retaining structures which are separate from the building (such as site walls) and can be expected to deflect sufficiently to mobilize the full active earth pressure condition should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at Ieast 45 pcf for backfill consisting of the on-site soils. All foundation and retaining structures should be designed for appropriate hydrostatic and surcharge pressures such as adjacent footings, traffic, construction materials and equipment. The pressures recommended above assume drained conditions behind the walls and a horizontal backfill surface. The buildup of water behind a wall or an upward sloping backfill surface will increase the lateral pressure imposed on a foundation wall or retaining structure. An underdrain should be provided to prevent hydrostatic pressure buildup behind walls. Backfill should be placed in uniform lifts and compacted to at least 90% o of the maximum standard Proctor density at a moisture content near optimum. Backfill placed in pavement and walkway areas should be compacted to at least 95°;) of the maximum standard Proctor density. Care should be taken not to overcompact the backfill or use large equipment near the wall, since this could cause excessive lateral pressure on the wall. Some settlement of deep wall backfill should be expected, even if the material is placed correctly, and could result in distress to facilities constructed on the backfill. The lateral resistance of foundation or retaining wall footings will be a combination of the sliding resistance of the footing on the foundation materials and passive earth pressure against the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated based on a coefficient of friction of 0.30 for the silt and clay soils and 0.5 for the coarse granular soils. Passive pressure of compacted backfill against the sides of the footings can be calculated using an equivalent fluid unit weight of 300 pcf. The coefficient of friction and passive pressure values recommended above assume ultimate Job No. 115023A Gastech -8 - soil strength. Suitable factors of safety should be included in the design to limit the strain which will occur at the ultimate strength, particularly in the case of passive resistance. Fill placed against the sides of the footings to resist lateral loads should be compacted to at least 95% of the maximum standard Proctor density at a moisture content near optimum. FLOOR SLABS The on-site soils, exclusive of topsoil, appear suitable to support the proposed slab -on - grade construction. There could be some differential settlement due to the variable soil conditions, mainly the silt and clay soils. We recommend at least 2 feet of granular structural fill, similar to that recommended below footings, be placed below floor slabs to help mitigate the settlement risk. To reduce the effects of some differential movement, floor slabs should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage cracking. The requirements for joint spacing and slab reinforcement should be established by the designer based on experience and the intended slab use. A minimum 4 inch layer of relatively well graded sand and gravel should be placed beneath interior slabs for subgrade support and to break capillary moisture rise. This material should consist of minus 2 inch aggregate with at least 50% retained on the No. 4 sieve and less than 12% passing the No. 200 sieve. All fill materials for support of floor slabs should be compacted to at least 95% of maximum standard Proctor density at a moisture content near optimum. Required fill should consist of granular soils devoid of vegetation, topsoil and oversized rock. UNDERDRAIN SYSTEM Although free water was not encountered in the exploratory borings and pits, it has been our experience in the area and with shallow clay soils that local perched groundwater can develop during times of heavy precipitation or seasonal runoff. Frozen ground during spring runoff can also create a perched condition. We recommend below -grade construction, such as retaining walls, be protected from wetting and hydrostatic pressure buildup by an underdrain system. Job No. 115 023A Gertech -9 The drains should consist of drainpipe placed in the bottom of the wall backfill surrounded above the invert level with free -draining granular material. The drain should be placed at each level of excavation and at least 1 foot below lowest adjacent finish grade and sloped at a minimum 1% to a suitable gravity outlet or drywell based in the underlying coarse granular soils. Free -draining granular material used in the underdrain system should contain less than 2% passing the No. 200 sieve, less than 50% passing the No. 4 sieve and have a maximum size of 2 inches. The drain gravel backfill should be at least 11/2 feet deep. SITE GRADING The risk of construction -induced slope instability at the site appears low provided the building is located in the flat part of the site as planned and cut and fill depths are Iimited, such as at the perimeter areas of the project site. We assume cut and fill depths for foundations, walls and pavement areas will not exceed about 5 feet. Embankment fills should be compacted to at least 95% of the maximum standard Proctor density near optimum moisture content. Prior to fill placement, the subgrade should be carefully prepared by removing all vegetation and topsoil and compacting to at least 95% of the maximum standard Proctor density. The fill should be benched into slopes that exceed 20% grade. PAVEMENT SECTION Asphalt surfaced driveway and parking areas are proposed for the project. Concrete pavement will also be used in apron areas against the building and in the depressed truck dock ramp. ESAL traffic loadings for the pavement areas provided to us consist of 143 in parking areas, 92,652 at the entrance drive and 92,509 at the yard areas/entrance drive which include the various truck traffic. The subgrade soils encountered at the site are generally low plasticity sandy silt and clay which are considered a relatively poor support for pavement sections. Structural fill will be needed for the pavement construction in some areas. The imported soils should be a granular material with a minimum Hveem stabilometer 'R' value of 30. Based on the traffic loadings provided, the silt and clay subgrade condition and our experience with similar projects, we recommend the Job No. 1 l5 023A Gec-tech -10 - minimum pavement section for passenger vehicle only areas consist of 3 inches of asphalt over 4 inches of base course on 8 inches of granular subbase. In the entrance drive and yard areas which include heavy truck traffic, 4 inches of asphalt over 6 inches of base course on 12 inches of granular subbase is recommended. The concrete pavement in the aprons next to the building and in the dock ramp should consist of at Ieast 6 inches of Portland cement concrete over 4 inches of road base on 12 inches of granular subbase. The asphalt should be a batched hot mix, approved by the engineer and placed and compacted to the project specifications. The base course and subbase should meet CDOT Class 6 and Class 2 specifications, respectively. All base course, subbase and required subgrade fill should be compacted to at least 95c.% of the maximum standard Proctor density at a moisture content within 2% of optimum. The section thicknesses assume structural coefficients of 0.14 for aggregate base course, 0.10 for aggregate subbase, 0.44 for asphalt surface and design strength of 4,500 psi for Portland cement concrete. The material properties and compaction should be in accordance with the project specifications. Required fill to establish design subgrade level should consist of imported granular soils. Prior to fill placement the subgrade should be stripped of vegetation and topsoil, scarified to a depth of 8 inches, adjusted to near optimum moisture content and compacted to at least 95% of standard Proctor density. In soft or wet areas a geogrid and/or subexcavation and replacement with aggregate base soils may be needed for stabilization. The subgrade should be proofrolled. Areas that deflect excessively should be corrected before placing pavement materials. The subgrade improvements and placement and compaction of base and asphalt materials should be monitored on a regular basis by a representative of the geotechnical engineer. SURFACE DRAINAGE The following drainage precautions should be observed during construction and maintained at all times after the facilities have been completed: 1) Inundation of the foundation excavations and underslab areas should be avoided during construction. Job No. 115 023A Gtech 2) Exterior backfill should be adjusted to near optimum moisture and compacted to at least 95% of the maximum standard Proctor density in pavement and slab areas and to at least 90°'0 of the maximum standard Proctor density in landscape areas. 3) The ground surface surrounding the exterior of the building should be sloped to drain away from the foundation in all directions. We recommend a minimum slope of 6 inches in the first 10 feet in unpaved areas and a minimum slope of 2't2 inches in the first 10 feet in paved areas. Free -draining wall backfill should be covered with filter fabric and capped with about 2 feet of the on-site fine-grained soils to reduce surface water infiltration. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. 5) Landscaping which requires regular heavy irrigation should be located at least 5 feet from foundation walls. LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this area at this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings drilled at the locations indicated on Figure 1, the proposed type of construction and our experience in the area. Our services do not include determining the presence, prevention or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. Our findings include interpolation and extrapolation of the subsurface conditions identified at the exploratory borings and variations in the subsurface conditions may not become evident until excavation is performed. If conditions encountered during construction appear different from those described in this report, we should be notified so that re-evaluation of the recommendations may be made. Job No. 115023A ~Ptech - 12 - This report has been prepared for the exclusive use by our client for design purposes. We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation and field services during construction to review and monitor the implementation of our recommendations, and to verify that the recommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications to the recommendations presented herein. We recommend on-site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the geotechnical engineer. Respectfully Submitted, HEPWORTH - PAWLAK GEOTECHNICAL, INC. Steven L. Pawlak, P.E. Reviewed by: Daniel E. Hardin, P.E. SLPiksw cc: M. Design Fusion, LLC - Michael Fa (mfa u.desw fusion.biz) High Country Engineering -- Roger Neal (rneal(a.;hceng.com) Job No. 115 023A Gtech APPROXIMATE SCALE 1"=80' f 115 023A GecPtech HEPwoRTH•PAwtAK GEorEcHnicAL LOCATION OF EXPLORATORY BORINGS AND PITS Figure 1 Elevation - Feet Elevation - Feet BORING 1 ELEV. = 5949' BORING 2 ELEV. = 5949 BORING 3 ELEV. = 5952 - 5955 5955 5950 5945 - 5940 APPROXIMATE PROPOSED DRIVEWAY GRADE 31/12 WC=5.8 5/12 DD=100 -200=52 LL=26 9/12 PI=4 WC=6.9 +4=24 -200=49 21/12 WC =3.4 +4=26 -200: 44 1316,50.+2 ... 6/12 / WC= 117 DD -103 -200=75 =2 LL23 PI=2 i--� 6/12 4/12 WC=22.0 DD=94 -200=91 LL== 25 PI=5 UC 700 3/6,17/6 5950 5945 5940 - 5935 5935 - 5955 - 5950 5945 - 5940 5935 BORING 4 ELEV. = 5953' T BORING 5 ELEV. = 5950' BORING 6 ELEV. = 5950.5' APPROXIMATE PROPOSED DRIVEWAY GRADE e -i 4,12 WC=13.4 DD=98 -200=75 �i— 4112 LppL=24 WC=18.18 2 DD=103 -200=82 LL=24 / PI=4 4112 51/12 6,12 Y. 50/3 WC -17.3 DID =90 -200 91 LL =27 PI= 4 UC = 1,150 Note. Explanation of symbols is shown on Figure 4. 7-; 5/12 5/12 WC=23,6 DD=93 -200=93 LL=27 PI=5 UC=1,200 '/— 6/12 4711 9/12 ;/.1 79112 5955 5950 5945 5940 5935 Elevation - Feet Elevation - Feet 115 023A H HEPWORTH-PAWLAK GEOTECHNICAL LOGS OF EXPLORATORY BORINGS DRIVEWAY AND PARKING AREAS Figure 2 Elevation - Feet Elevation - Feet - 5950 - 5945 - 5940 - 5935 BORING 7 BORING 8 BORING 9 BORING 10 ELEV. = 5950.5' ELEV. = 5949.5' ELEV. = 5949.5 ELEV. = 5949.5' 50/4 40/6,50/1 WC=3.1 +4=42 -200=19 PROPOSED FLOOR ELEV. = 5952' 50/1 6/12 '1 WC 20 8 I DD=99 7/12 23/12 50/2 5/12 WC 20 DD --100 J 200 •= 91 UC=2,500 6/12 WC 281 DDS 100 47/12 e4� 50/5 5950 5945 5940 5935 - 5930 5930 - 5950 5945 - 5940 - 5935 BORING 11 ELEV. = 5949' v ,1 8/12 WC=23.9 DD=96 ' 8/12 WC=22.2 D0=100 -200=89 � UC=3,100 91/11 a a: WC=2.0 +4=60 -200=10 BORING 12 ELEV. = 5950' 15/6,27/6 31/12 57/12 BORING 13 ELEV. = 5949' 7/12 7/12 WC -27 8 DD -92 77/12 50/6 Note: Explanation of symbols is shown on Figure 4. BORING 14 ELEV. = 5950.5 5950 22/6,50/1 57/12 WCa23 +4 = 45 5945 -200 - 22 5940 5935 Elevation - Feet Elevation - Feet 115 023A GecPteCh HEPWORTH-PAWLAK GEOTECHNICAL LOGS OF EXPLORATORY BORINGS BUILDING AREA Figure 3 LEGEND: ---7 z 31/12 T NOTES: TOPSOIL; organic sandy silt and clay, root zone, brown. CLAY (CL); slightly sandy to sandy, silty, medium stiff to stiff, very moist, red, low to medium plasticity. SILT AND CLAY (ML -CL); slightly sandy to sandy, medium stiff, very moist, red, low plasticity. SAND (SM -SC); very silty, slightly clayey, scattered gravel to gravelly, loose to medium dense, slightly moist, red. GRAVEL AND COBBLES (GM -GP); sillty to slightly silty, sandy, boulders, dense, slightly moist, red -brown, rounded rock. Relatively undisturbed drive sample; 2 -inch I.D. California liner sample. Drive sample; standard penetration test (SPT), 1 3/8 inch I.D. split spoon sample, ASTM D-1586. Drive sample blow count; indicates that 31 blows of a 140 pound hammer falling 30 inches were required to drive the California or SPT sampler 12 inches. Practical drilling refusal. 1. Exploratory borings were drilled on January 27 (Borings 1-6) and February 3 (Borings 7-14), 2015 with 4 -inch diameter continuous flight power auger. 2. Locations of exploratory borings were measured approximately by pacing from features shown on the site plan provided. 3. Elevations of exploratory borings were obtained by interpolation between contours shown on the site plan provided 4. The exploratory boring locations and elevations should be considered accurate only to the degree implied by the method used. 5. The lines between materials shown on the exploratory boring logs represent the approximate boundaries between material types and transitions may be gradual. 6. No free water was encountered in the borings at the time of drilling. Fluctuation in water level may occur with time. 7. Laboratory Testing Results: WC = Water Content (%) DD = Dry Density (pcf) +4 - Percent retained on the No. 4 sieve -200 = Percent passing No. 200 sieve LL = Liquid L; mit (%) PI = Plasticity Index (%) UC = Unconfined Compressive Strength (psf) 115 023A GelSteCh HEPWORTH-PAWLAK GEOTECHNICAL LEGEND AND NOTES EXPLORATORY BORINGS Figure 4 Depth - Feet - 0 - 5 - 10 LEGEND: —7 00 0-9 _J PROFILE PIT 1 ELEV.= 5949.5' / / / GRAVEL- 0 - i SAND- 26 - SILT.- 55 CLAY=17 PROFILE PIT 2 ELEV. = 5949' • O TOPSOIL; organic sandy silt and clay, root zone, brown. SILT AND CLAY (ML -CL); slightly sandy to sandy, medium stiff, very moist, red, low plasticity. 5 10 GRAVEL AND COBBLES (GM -GP); sillty to slightly silty, sandy, boulders, dense, slightly moist, red -brown, rounded rock. Disturbed bulk sample. NOTES: 1. Exploratory pits were excavated on February 24, 2015 with a Cat 416B backhoe. 2. Locations of exploratory pits were measured approximately by pacing from features shown on the site plan provided. 3. Elevations of exploratory pits were obtained by interpolation between contours shown on the site plan provided. 4. The exploratory pit locations and elevations should be considered accurate only to the degree implied by the method used. 5. The lines between materials shown on the exploratory pit logs represent the approximate boundaries between material types and transitions may be gradual. 6. No free water was encountered in the pits at the time of excavating. Fluctuation in water level may occur with time. 7. Laboratory Testing Results: Gravel = Percent retained on No. 10 Sieve Sand = Percent passing No. 10 sieve and retained on No. 325 sieve Silt = Percent passing No. 325 sieve to particle size .002mm Clay = Percent smaller then particle size .002mm Depth - Feet 115 023A Gech HEPWORTFHPAWLAK GEOTECHNICAL LOGS OF EXPLORATORY PITS Figure 5 Compression °h Compression 0 1 2 3 4 0 1 2 3 4 5 6 7 Moisture Content = 20.8 percent Dry Density = 99 pcf Sample of: Sandy Silty Clay From: Baring 9 at 2 y2 Feet — — Compression upon wetting 0.1 .0 10 APPLIED PRESSURE - ksf Moisture Content = 28.1 Dry Density = 100 Sample of: Sandy Silty Clay From: Boring 10 at 5 Feet No movement upon wetting percent pcf 0.1 1.0 0 APPLIED PRESSURE - ksf 100 115 023A G grtech HEPWOHTH•PAWLAK GEOTECHNICAL SWELL -CONSOLIDATION TEST RESULTS Figure 6 Compression Compression 0 1 2 3 4 5 6 0 1 2 3 4 5 Moisture Content = 23.9 percent Dry Density = 98 pcf Sample of: Sandy Silty Clay From: Boring 11 at 2 yz Feet Compression upon wetting 0.1 1.0 10 APPLIED PRESSURE - ksf Moisture Content = 27.8 Dry Density = 92 Sample of: Sandy Silty Clay From: Boring 13 at 5 Feet Compression upon wetting percent pcf 0.1 1.0 10 APPLIED PRESSURE - ksf 00 0i; 115 023A Gegtedh HEPW0RTH•PAWLAK GEOTECHNICAL SWELL -CONSOLIDATION TEST RESULTS Figure 7 ti i1; f2[210 HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES 1 CLEAR SQUARE OPENINGS 4 1IIN.15HHMIN. 60MIN19MIN.4 MIN. 1 MIN. #200 #100 #50 #30 #16 #8 #4 3/8" 3/4" 1 112' 3' 5'6' 8" 0 10 20 30 40 50 60 70 80 90 100 f • { {- • 001 ,992 005 .009 019 037 .074 I50 .300 .600 118 2.99 4.75 9.5 12 5 19.0 37.5 76 2 152 203 127 DIAMETER OF PARTICLES IN MILLIMETERS CLAY TO SILT GRAVEL 24 % LIQUID LIMIT % SAMPLE OF: Very Silty Clayey Gravelly Sand SAND GRAVEL FINE MEDIUM 1 COARSE FINE I COARSE COBBLES SAND 27 % SILT AND CLAY 49 % PLASTICITY INDEX % FROM: Boring 1 at 5 Feet too 90 80 U1 7o Z V7 U3 60 d So Z U 40 W 0- 30 30 20 10 0 HYDROMETER ANALYSIS I SIEVE ANALYSIS I TIME READINGS 1 U S STANDARD SER;ES 1 CLEAR SQUARE OPENINGS 051 1N 15 MIN 60MIN19MIN.4 MIN 1 MIN #200 #100 #50 #30 #16 #8 #4 318" 314' 1 1/2 3` 5°8' 8' 100 I 10 20 30 40 50 60 70 80 90 100 001 .002 • 90 80 0 70 Z U) U3 60 1- 50LZL U 40 Lu CC 30 20 10 0 .005 .009 .019 037 .074 150 300 .600 1.18 2.36 4.75 9 512 519.0 37.5 76 2 1452 203 DIAMETER OF PARTICLES IN MILLIMETERS CLAY TO 51LT GRAVEL 26 % LIQUID LIMIT % SAMPLE OF: Very Silty Clayey Gravelly Sand SANG FINE 1 MEDIUM 1 COARIE GRAVEL FINE 1 COARSE SAND 30 % SILT AND CLAY 44 % PLASTICITY INDEX % FROM: Boring 2 at 2 yZ Feet 115 023A Gertech HEPWORTH•PAWLAH GEOTECHNICAL GRADATION TEST RESULTS Figure 8 IMINIOZ1111IMMIZIOI 20E•10t111:IarlIZImoi.' HYDROMETER ANALYSIS I SIEVE ANALYSIS 1 TIME READ NGS 1 U.S STANDARD SERIES 1 CLEAR SQUARE OPENINGS l TUN 15 MIN 60MIN19MIN.4 MIN 1 M.N #200 #100 #50 #30 #16 #8 #4 318" 314' 1 112" 3" 5"6' 8° 0 10 20 30 40 50 60 70 80 90 100 90 80 001 .002 005 009 .019 037 074 150 303 000 1 IB 2 30 DIAMETER OF PARTICLES IN MILLIMETERS CLAY TO SILT GRAVEL 42 % LIQUID LIMIT % SAMPLE OF: Silty Sandy Gravel FINE 1 SAND MED UM 1COARE 4.75 95125 19.0 37.5 702 152 203 Gi1AVEL FINE I COARSE 127 COBBLES SAND 39 % SILT AND CLAY 19 % PLASTICITY INDEX % FROM: Boring 7 at 4 Feet 70 00 50 40 30 20 10 0 HYDROMETER ANALYSIS I SIEVE ANALYSIS Ili. TIME READINGS U.S. STANDARD SERIES 1 CLEAR SQUARE OPENINGS 0 IN. 15 MIN.60MIN19MIN.4 MIN. 1 MIN. #200 #100 #50 #30 #16 #8 #4 3/8" 314" 1 1!2" 3' 5'6" 8"100 1 10 20 30 40 50 60 70 80 90 100 .001 .002 .005 .009 .019 .037 .074 .150 .300 .600 1.18 2.36 4 75 9.512 519.0 37.5 76.2 12152 203 DIAMETER OF PARTICLES IN MILLIMETERS 1 90 ENT PA "MEW 80 70 Z 60 a F- 50ZU U 40 CC a. 30 20 10 0 CLAY 70 50.7 SAND FINE 1 MEDIUM 1 COARSE GRAVEL COBBLES FINE 1 COARSE GRAVEL 60 % LIQUID LIMIT % SAMPLE OF: Slightly Silty Sandy Gravel SAND 30 % SILT AND CLAY 10 % PLASTICITY INDEX % FROM: Boring 11 at 10 Feet 115 023A Gertech HEPWORTH-PAWLAK GEOTECHNICAL GRADATION TEST RESULTS Figure 9 2-21:14KM:01.1121 HYDROMETER ANALYSIS SIEVE ANALYSIS 4 Mq qq TIME READINGS U S STANDARD SERIES 1 CLEAR SQUARE OPENINGS l ] 0 45 MIN. 15 VAN.60MIN19MIN.4 MIN. 1 MIN. #200 #100 #50 #30 #16 #B #4 3/8' 314" 1 1/2' 3' 5'6' 6" 100 10 20 30 40 50 60 70 80 90 k 1 1 90 80 70 60 50 40 30 20 10 loo 1 o 001 .002 .005 .009 .019 037 074 ,150 300 .600 1.18 2.36 4.75 9.5 19.0 37.5 762 152 203 12.5 127 DIAMETER OF PARTICLES IN MILLIMETERS CLAY TO &0.T FW. SAND me Dom 1 CRnvEi �g� FINE 1 COARSE GRAVEL 45 % SAND 33 % SILT AND CLAY 22 % LIQUID LIMIT % PLASTICITY INDEX % SAMPLE OF: Silty Sandy Gravel FROM: Boring 14 at 4 Feet 115 023A Gertech I-IEPWORTH•PAWLAK GEOTECHNICAL GRADATION TEST RESULTS Figure 10 RCENT RETAIN !� HYDROMETER ANALYSIS I SIEVE ANALYSIS I H� �{q TIME READINGS U.S. STANDARD SERIES 1 CLEAR SQUARE OPENINGS 0 45 MIN 15 MIN.60MIN19MIN,4 MIN.1 MIN. #140 #60 #35 #18 #10 #4 318' 3/4" 1 112" 3" 5'6" 8' 100 24 10 20 30 40 50 60 70 80 90 100 .001 .002 .005 .009 .019 1- CLAY SILT .045 .106 .025 .500 1.00 2 00 DIAMETER OF PARTICLES IN MILLIMETERS SAND V. FINE 1 FME 1 MEDIUM !COARSE IY CONSL 90 80 70 60 50 40 30 20 10 0 4.75 9.5 19.0 37.5 76.2 152 203 GRAVEL SMALL 1 MEDIUM 1 LARGE COBBLES 115 023A GRAVEL 0 % SAND 28 % SILT 55 % USDA SOIL TYPE: Silt Loam HEPWORTH'PAWLAK GEOTECHNICAL CLAY 17 % FROM: Profile Pit 1 at 3 to 4 Feet USDA GRADATION TEST RESULTS :fili+IEIt`-.1121% Figure 11 HEPWORTH-PAWLAK GEOTECHNICAL, INC. TABLE 1 SUMMARY OF LABORATORY TEST RESULTS SAMPLE LOCATION NATURAL MOISTURE CONTENT (%} NATURAL DRY DENSITY (pcf) GRADATION PERCENT PASSING NO. 200 SIEVE ATTERBERG LIMITS UNCONFINED COMPRESSIVE STRENGTH (PSF) BORING DEPTH (ft) GRAVEL %` SAND {%� LIQUID LIMIT (%j PLASTIC INDEX (%) 1 2'/2 5.8 100 52 26 4 5 6.9 24 27 49 2 21/2 3.4 26 30 44 3 2'/ 11.7 103 75 23 2 10 22.0 94 91 25 5 700 4 21/2 13.4 98 75 24 2 5 18.8 103 82 24 3 1,700 5 21/2 17.3 90 91 27 4 1,150 6 5 23.6 93 93 27 5 1,200 7 4 3.1 42 39 19 HEPWORTH-PAWLAK GEOTECHNICAL, INC. TABLE 1 SUMMARY OF LABORATORY TEST RESULTS SAMPLE LOCATION NATURAL MOISTURE CONTENT (%) NATURAL DRY DENSITY (pcf} GRADATION PERCENT PASSING NO. 200 SIEVE ATTERBERG LIMITS UNCONFINED COMPRESSIVE STRENGTH (PSF) BORING DEPTH (ft) GRAVEL (%) SAND (%) LIQUID LIMIT (%) PLASTIC INDEX (%) 9 21 20.8 99 10 21/2 20.8 100 91 2,500 5 28.1 100 11 21/2 23.9 98 5 22.2 100 89 3,100 10 2.0 60 30 10 13 5 27.8 92 14 4 2.3 45 33 22 HEPWORTH-PAWLAK GEOTECHNICAL, INC. TABLE 2 PERCOLATION TEST RESULTS JOB NO. 115 023A HOLE NO. HOLE DEPTH (INCHES) LENGTH OF INTERVAL (MIN) WATER DEPTH AT START OF INTERVAL (INCHES) WATER DEPTH AT END OF INTERVAL (INCHES) DROP IN WATER LEVEL (INCHES) AVERAGE PERCOLATION RATE (MIN./INCH) P-1 35 15 Water Added Water Added 6 5 1 30 6% 51/4 %2 5% 51/4 % 6%2 6 %2 6 5'/: 51/2 5 '/ P-2 38 15 Water Added Water Added 5 41/2 %2 30 5% 5 5 4%2 %2 6 5'/2 '/2 5%: 5 5 4'/2 '/2 P-3 40 15 7 6% 1/2 60 6f2 6% i 6% 5% '/2 5'/ 51/3 5%2 5% '/. 5% 5 ''4 P-4 38 15 Water Added 6 5%2 %2 45 6 5% 14 5% 51/2 IA 5%2 5 %2 5 4'/= '/. 4'/ 41/2 14 Note: Percolation test holes were hand dug in the bottom of backhoe pits and soaked on February 24, 2015. Percolation tests were conducted on February 25, 2015. The average percolation rates were based on the last three readings of each test.