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HomeMy WebLinkAboutHARMONY COMMONS - PDP - PDP150027 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGEOTECHNICAL SUBSURFACE EXPLORATION REPORT HTP NORTH RETAIL AND OFFICE CENTER FORT COLLINS, COLORADO SOILOGIC # 15-1138 July 1, 2015 Soilogic, Inc. 3050 67th Avenue, Suite 200 Greeley, CO 80634  (970) 535-6144 P.O. Box 1121  Hayden, CO 81639  (970) 276-2087 July 1, 2015 Brinkman Partners 3528 Precision Drive, Suite 100 Fort Collins, Colorado 80528 Attn: Ms. Tina Hippeli Re: Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Harmony Technology Park Fort Collins, Colorado Soilogic Project # 15-1138 Ms. Hippeli: Soilogic, Inc. (Soilogic) personnel have completed the geotechnical subsurface exploration you requested for the proposed HTP North Retail and Office Center to be developed at the Harmony Technology Park in south Fort Collins, Colorado. The results of our exploration and pertinent geotechnical engineering recommendations are included with this report. The subsurface materials encountered in the completed test borings generally consisted of approximately 3 to 6 inches of vegetation and topsoil underlain by light brown to brown/reddish brown lean clay with varying amounts of silt and sand. The lean clay varied from soft to very stiff in terms of consistency, exhibited no to low swell potential at in-situ moisture and density conditions and extended to the bottom of borings B-2, B-3, B-4, B-8, B-9 and B-14 through B-18 at depths ranging from approximately 10 to 15 feet below present site grade. At boring locations B-1, B-5, B-6, B-7, the lean clay extended to depths ranging from approximately 13½ to 14½ feet below ground surface and was underlain by a thin layer of reddish brown sand and gravel. The sand and gravel varied from loose to medium dense in terms of relatively density, would be expected to be non- expansive or possess low swell potential based on the materials physical properties and engineering characteristics and extended to the bottom of borings B-1, B-5 and B-7 at a depth of approximately 15 feet below present site grade. At boring location B-6, the sand and gravel extended to a depth of approximately 14½ feet below ground surface and was underlain by brown/grey/rust claystone with interbedded siltstone/sandstone bedrock. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Harmony Technology Park Fort Collins, Colorado Soilogic # 15-1138 2 Claystone with siltstone/sandstone bedrock was encountered underlying the sandy lean clay at boring locations B-10 through B-13 at depths ranging from approximately 14½ to 22 feet below ground surface. The claystone varied from weathered to very hard in terms of relative hardness, would be expected to exhibit low to moderate swell potential based on experience with other explorations performed in this area and extended to the bottom of borings B-10 through B-13 at depths ranging from approximately 15 to 25 feet below present site grade. Groundwater was encountered in several of the completed site borings when checked immediately after completion of drilling. When checked approximately 5 days after completion of drilling, groundwater was measured at depths of approximately 14 feet below ground surface at boring locations B-1 through B-5, 13 feet at boring locations B- 6, B-10 and B-11 and 12 feet below ground surface at boring locations B-9, B-12 and B- 13. Groundwater was measured at depths of approximately 10 and 4 feet below ground surface at boring locations B-17 and B-18 respectively at that time. Borings B-7, B-8, B- 14, B-15 and B-16 were observed to be dry to the approximate depths explored about 5 days after drilling. Based on the subsurface conditions encountered and type of construction proposed, it is our opinion the retail/office buildings could be constructed with conventional spread footing foundations and floor slabs bearing on natural, undisturbed lean clay with low swell potential and/or properly placed and compacted low volume change (LVC) fill soils developed as outlined in this report. Due to the anticipated moderate foundation loads for the apartment building, we recommend this structure be supported on drilled pier foundations extended into bedrock underlying the site. The site lean clay also appears suitable for use as LVC fill to develop the site and for support of site pavements and exterior flatwork. Depending on the in-place moisture content of the pavement subgrade soils immediately prior to surfacing, stabilization of the pavement subgrades may be necessary to develop a suitable paving platform. Recommendations concerning utility installation and pavement section design options are included with this report. Other opinions and recommendations concerning design criteria and construction details for the proposed site improvements are also included. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Harmony Technology Park Fort Collins, Colorado Soilogic # 15-1138 3 We appreciate the opportunity to be of service to you on this project. If you have any questions concerning the enclosed information or if we can be of further service to you in any way, please do not hesitate to contact us. Very Truly Yours, Soilogic, Inc. Reviewed by: Wolf von Carlowitz, P.E. Darrel DiCarlo, P.E. Principal Engineer Senior Project Engineer 36746 44271 GEOTECHNICAL SUBSURFACE EXPLORATION REPORT HTP NORTH RETAIL AND OFFICE CENTER FORT COLLINS, COLORADO SOILOGIC # 15-1138 July 1, 2015 INTRODUCTION This report contains the results of the completed geotechnical subsurface exploration for the HTP North Retail and Office Center to be developed at the Harmony Technology Park in Fort Collins, Colorado. The purpose of our exploration was to describe the subsurface conditions encountered in the completed site borings and develop the test data necessary to provide recommendations concerning design and construction of the building foundations and support of floor slabs, exterior flatwork and site pavements. Recommendations concerning utility installation and pavement section design options are also included. The conclusions and recommendations outlined in this report are based on results of the completed field and laboratory testing and our experience with subsurface conditions in this area. PROPOSED CONSTRUCTION We understand this project involves the construction of four (4) retail/restaurant buildings, one (1) medical/office building and one (1) apartment building in the Harmony Technology Park, located southwest of the intersection of East Harmony Road and Lady Moon Drive in south Fort Collins, Colorado. The retail/restaurant buildings are expected to be single-story constructed as slab-on-grade. The medical/office building is expected to be a two-story structure, also constructed as slab-on-grade. The apartment building is expected to be a five (5) story wood-frame structure constructed over a podium first floor parking area, including 1,500 square feet of first floor retail space. Foundations loads for one and two-story structures are expected to be light, with continuous wall loads less than 3.5 kips per lineal foot and individual column loads less than 75 kips. Foundation loads for the apartment building are expected to be light to moderate, with continuous wall loads less than 3.5 kips per lineal foot and individual column loads less than 200 kips. Floor loads are expected to be light, less than 100 psf. If the assumed construction and loading conditions vary substantially from those assumed, Soilogic should be contacted to reevaluate the recommendations in this report. Infrastructure improvements for the Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 2 development will include utility installation and construction of a site detention pond and site drive and parking area pavements. Small grade changes are anticipated to develop finish site grades in the building and pavement areas. SITE DESCRIPTION The development property includes an approximate 10-acre parcel located southwest of the intersection of East Harmony Road and Lady Moon Drive in south Fort Collins, Colorado. At the time of our site exploration, the property was being used for agricultural purposes and contained wheat crop approximately 3-feet in height. An apparent storm water ditch/detention area was observed to be running in a general east- west direction and located immediately south of the proposed detention pond area. The site as observed to be relatively level, with a gentle overall slope downward to the southeast and a maximum difference in ground surface elevation across the project site estimated to be approximately 10 feet based on topographic maps of the area. SITE EXPLORATION Field Exploration To develop subsurface information for the proposed construction, a total of eighteen (18) soil borings were completed. Two (2) borings were advanced in each of the retail/ restaurant and medical office building areas and three (3) borings advanced in the apartment building area. The structure borings were extended to depths between approximately 15 and 25 feet below present site grades. Three (3) borings were advanced in site drive and parking areas to a depth of approximately 10 feet below ground surface and two (2) borings completed in the detention pond area to a depth of approximately 15 feet below ground surface. The boring locations were established in the field by Soilogic personnel based on a provided site plan, using a mechanical surveyor’s wheel and estimating angles from identifiable site references. The boring locations should be considered accurate only to the degree implied by the methods used to make the field measurements. A diagram indicating the approximate boring locations is included with this report. Graphic logs of each of the auger borings are also included. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 3 The test holes were advanced using 4-inch diameter continuous-flight auger, powered by a truck-mounted CME-55 drill rig. Samples of the subsurface materials were obtained at regular intervals using California barrel sampling procedures in general accordance with ASTM specification D-1586. As part of the D-1586 sampling procedure, standard sampling barrel is driven into the substrata using a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the sampler a distance of 12 inches is recorded and helpful in estimating the consistency, relative density or hardness of the soils or bedrock encountered. In the California barrel sampling procedure, lesser disturbed samples are obtained in removable brass liners. Samples of the subsurface materials obtained in the field were sealed and returned to the laboratory for further evaluation, classification and testing. Laboratory Testing The samples collected were tested in the laboratory to measure natural moisture content and visually and/or manually classified in accordance with the Unified Soil Classification System (USCS). The USCS group symbols are indicated on the attached boring logs. An outline of the USCS classification system is included with this report. Classification of bedrock was completed through visual and tactual observation of disturbed samples. Other bedrock types could be revealed through petrographic analysis. As part of the laboratory testing, a calibrated hand penetrometer (CHP) was used to estimate the unconfined compressive strength of essentially cohesive specimens. The CHP also provides a more reliable estimate of soil consistency than tactual observation alone. Dry density, Atterberg limits, -200 wash and swell/consolidation tests were completed on selected samples to help establish specific soil characteristics. Atterberg limits tests are used to determine soil plasticity. The percent passing the #200 size sieve (-200 wash test) is used to determine the percentage of fine grained soils (clay and silt) in a sample. Swell/consolidation tests are performed to evaluate soil and bedrock volume change potential with variation in moisture content. The results of the completed laboratory tests are outlined on the attached boring logs and swell/consolidation test summaries. As part of the laboratory testing, water-soluble sulfate content tests were completed on four (4) selected samples to help evaluate corrosive soil characteristics with respect to buried concrete and results discussed subsequently in this report. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 4 SUBSURFACE CONDITIONS The subsurface materials encountered in the completed site borings can be summarized as follows. A thin layer of vegetation and topsoil was encountered at the ground surface at the boring locations. The vegetative soil layer was underlain by light brown to brown/ reddish brown lean clay with varying amounts of silt and sand. The lean clay varied from soft to very stiff in terms of consistency, exhibited no to low swell potential at in-situ moisture and density conditions and extended to the bottom of borings B-2, B-3, B-4, B- 8, B-9, B-14, B-15, B-16, B-17 and B-18 at depths ranging from approximately 10 to 15 feet below present site grade. At boring locations B-1, B-5, B-6, B-7, the lean clay extended to depths ranging from approximately 13½ to 14½ feet below ground surface and was underlain by a thin layer of reddish brown sand and gravel. The sand and gravel varied from loose to medium dense in terms of relatively density, would be expected to possess low swell potential or be non-expansive based on the materials physical properties and engineering characteristics and extended to the bottom of borings B-1, B-5 and B-7 at a depth of approximately 15 feet below present site grade. At boring location B-6, the sand and gravel extended to a depth of approximately 14½ feet below ground surface and was underlain by brown/grey/rust claystone with interbedded siltstone/ sandstone bedrock. Claystone with siltstone/sandstone bedrock was also encountered underlying the sandy lean clay at boring locations B-10 through B-13 at depths ranging from approximately 14½ to 22 feet below ground surface. The claystone varied from weathered to very hard in terms of relative hardness, would be expected to exhibit low to moderate swell potential based on experience with other explorations performed in this area and extended to the bottom of borings B-10 through B-13 at depths ranging from approximately 15 to 25 feet below present site grade. The stratigraphy indicated on the included boring logs represents the approximate location of changes in soil and bedrock types. Actual changes may be more gradual than those indicated. Groundwater was encountered in several of the completed site borings when checked immediately after completion of drilling. When checked approximately 5 days after completion of drilling, groundwater was measured at depths of approximately 14 feet below ground surface at boring locations B-1 through B-5, 13 feet at boring locations B- Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 5 6, B-10 and B-11 and 12 feet below ground surface at boring locations B-9, B-12 and B- 13. Groundwater was measured at depths of approximately 10 and 4 feet below ground surface at boring locations B-17 and B-18 respectively at that time. Borings B-7, B-8, B- 14, B-15 and B-16 were observed to be dry to the approximate depths explored about 5 days after drilling. Groundwater level information is indicated in the upper right-hand corner of the attached boring logs. Groundwater levels will vary seasonally and over time based on weather conditions, site development, irrigation practices and other hydrologic conditions. Perched and/or trapped groundwater conditions may also be encountered at times throughout the year. Perched water is commonly encountered in soils overlying less permeable soil layers and/or bedrock. Trapped water is typically encountered within more permeable zones of layered soil and bedrock systems. The location and amount of perched and/or trapped water can also vary over time. ANALYSIS AND RECOMMENDATIONS Site Development All existing vegetation and topsoil should be completely removed from proposed building, pavement, exterior flatwork and any fill areas. After stripping and completing all cuts and prior to placement of any new fill, pavement materials and/or flatwork concrete, we recommend the exposed subgrade soils be scarified to a depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density. The moisture content of the scarified soils should be adjusted to within the range of ±2% of standard Proctor optimum moisture content at the time of compaction. Fill soils required to develop the site should consist of approved low volume change (LVC) soils free from organic matter, debris and other objectionable materials. Based on results of the completed laboratory testing, it is our opinion the site lean clay could be used as fill to develop the site. Essentially-granular structural fill materials could also be considered for use. It may be prudent to utilize the essentially cohesive site soils as fill in the apartment building area so that the upper shaft diameter of drilled pier foundations Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 6 can be more easily maintained in that area. Suitable fill soils should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted as recommended for the scarified soils above. Care should be taken to avoid disturbing reconditioned subgrades and site fill soils prior to placement of any overlying improvements. Soils which are allowed to dry out or become wet and softened or disturbed by the construction activities should be removed and replaced or reworked in place prior to concrete placement. Retail/Office Building Spread Footing Foundations Based on the materials encountered in the completed site borings and results of laboratory testing, it is our opinion the proposed lightly-loaded retail/restaurant and medical/office buildings could be supported by continuous spread footing and isolated pad foundations bearing on natural, undisturbed lean clay with low swell potential. For design of the footing foundations bearing on medium stiff to very stiff lean clay, we recommend using a maximum net allowable soil bearing pressure of 1,500 psf. Exterior footings should bear a minimum of 30 inches below finished adjacent exterior grade to provide frost protection. We recommend formed strip footings have a minimum width of 12 inches and isolated pad foundations have a minimum width of 24 inches in order to facilitate construction and reduce the potential for development of eccentrically loaded footings. Actual footing widths should be designed by a structural engineer. For design of footing foundations and foundation walls to resist lateral movement, a passive equivalent fluid pressure value of 250 pcf could be used. The top 30 inches of subgrade could be considered a surcharge load but should not be used in the passive resistance calculations. A coefficient of friction of 0.35 could be used between foundation and floor slab concrete and the bearing soils to resist sliding. The recommended passive equivalent fluid pressure value and coefficient of friction do not include a factor of safety. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 7 We estimate settlement of footing foundations designed and constructed as outlined above and resulting from the assumed structural loads would be on the order of 1 inch or less. Differential settlement could approach the amount of total settlement estimated above. If water from any source is allowed to infiltrate the foundation bearing soils, additional movement of the foundations could occur. Occasional zones of soft clay were encountered in the completed site borings. The soft lean clay would be easily disturbed by the construction activities. Care should be taken at the time of construction to avoid disturbing the foundation bearing soils and the need for corrective action. To reduce the potential of “pumping” and softening of the foundation soils at foundation bearing level and the requirement for corrective work, consideration should be given to completing foundations excavations remotely with a track-hoe. Careful observation of the exposed foundation bearing materials should be completed at the time of construction to ensure all footing foundations will be supported on like natural materials with suitable strength. If extensive zones of soft, high moisture content soils are encountered at that time, some overexcavation/backfill or other approved stabilization procedures may be required prior to foundation construction. Apartment Building Drilled Pier Foundations With the moderate foundation loads anticipated for the apartment building, we recommend this structure be supported on drilled pier foundations extended a minimum of ten (10) feet into competent bedrock. For design of drilled piers extended into competent bedrock underlying the site, we recommend using a maximum allowable end bearing pressure of 30 kips per square foot (ksf). An allowable skin friction value of 3,000 psf could be used for that portion of the pier extended into competent bedrock. Piers should be designed with a length/diameter ratio of 30 or less and full length steel reinforcement. Void form would not be required beneath foundation grade beams. For design of drilled piers to resist lateral loading, the horizontal modulus for varying pier diameters are outlined below in Table I. The values provided do not include a factor of safety. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 8 When the lateral capacity of drilled piers is evaluated by the L-Pile/Com64 design program, we recommend that internally generated load-deformation (p-y) curves be used. Piers may be designed using the following lateral load criteria. Parameters Overburden Sandy Lean Clay Claystone Bedrock In-Situ Unit Weight (pcf) 120 * 135* Angle of Internal Friction 15 20 Cohesion (psf) 300 5000 Strain at 50% .02 .015 * Reduce values by 62.4 pcf below groundwater table Group reductions would apply if piers are spaced within three (3) pier diameters of each other. Piers in line with the direction of lateral load should be spaced a minimum of six (6) pier diameters center-to-center based on the largest diameter pier in the series. The horizontal modulus for initial and trailing piers should be reduced if spacing less than six (6) pier diameters is required. Based on the materials encountered in the completed site borings, we expect the drilled caissons could be excavated using conventional power auger equipment. If zones of well cemented bedrock are encountered at the time of caisson construction, specialized rock augers or core barrels may be required to fully penetrate these materials. Based on the depth to groundwater observed and presence of cleaner granular soils immediately overlying the bedrock surface, we expect temporary casing sealed into the claystone bedrock underlying the site would be required during construction of the drilled shafts to prevent soils and groundwater from entering the pier excavations prior to concrete TABLE I – HORIZONTAL MODULUS OF SUBGRADE REACTION (tons/ft3) Pier Diameter (in) Overburden Sandy Lean Clay Claystone Bedrock 12 18 24 30 36 50 33 25 20 17 400 267 200 160 133 Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 9 placement. The zone of cleaner granular soils overlying the bedrock surface will require care by the contractor during drilling and setting of the temporary casing to develop a proper seal. A maximum 3-inch depth of groundwater is acceptable in the pier excavations immediately prior to free-fall concrete placement. If excessive depths of free water develop in the pier excavations prior to concrete placement, dewatering of the pier excavations should be completed or a tremmie used for concrete placement. Pier concrete should have a slump in the range of 5 to 7 inches and be placed in the pier excavations immediately after the completion of drilling, cleaning, and placement of reinforcing steel. Casing should be pulled in a slow and continuous manner while maintaining sufficient concrete head to prevent the infiltration of soil and water and the formation of voids within the shaft concrete. We estimate long term settlement of the drilled caisson foundations designed and constructed as outlined above and resulting from the assumed structural loads would be less than ¾-inch. Differential settlement could approach the amount of total settlement estimated above. Seismicity Based on our review of the International Building Code (2003), a soil profile type D could be used for the site strata. Based on our review of United States Geologic Survey (USGS) mapped information, design spectral response acceleration values of SDS = .218 (21.8%) and SD1 = .092 (9.2%) could be used. Foundation Wall Backfill Backfill placed adjacent to foundation walls and grade beams should consist of approved LVC soils free from organic matter, debris and other objectionable materials. The site lean clay could be used as backfill adjacent to foundation walls and grade beams provided the proper moisture content is developed in those materials at the time of placement and compaction. We recommend the site lean clay or similar soils be placed in loose lifts not to exceed 9 inches thick, adjusted to be within ±2% of the material’s standard Proctor optimum moisture content and compacted to at least 95% of the material’s standard Proctor maximum dry density. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 10 Excessive lateral stress can be imposed on foundation walls and grade beams when using heavier mechanical compaction equipment. We recommend compaction of unbalanced foundation wall backfill soils be completed using light mechanical or hand compaction equipment. Lateral Earth Pressures Below grade construction is not anticipated for the proposed site structures at this time. For design of any unilaterally loaded foundation walls where preventative measures have been taken to reduce the potential for development of hydrostatic pressures on the walls, we recommend using an active equivalent fluid pressure value of 40 pounds per cubic foot. Some rotation of the walls must occur to develop the active earth pressure state. That rotation can result in cracking of the walls typically in between corners and other restrained points. The amount of deflection of the top of the wall can be estimated at 0.5% times the height of the wall. An equivalent fluid pressure value of 60 pounds per cubic foot could be used for restrained wall conditions. Variables that affect lateral earth pressures include, but are not limited to; the swell potential of the backfill soils, backfill compaction and geometry, wetting of the backfill soils, surcharge loads and point loads developed in the backfill materials. The recommended equivalent fluid pressure values do not include a factor of safety or an allowance for hydrostatic loads. Use of expansive or high plasticity soil backfill, excessive compaction of wall backfill or surcharge loads placed adjacent to the basement walls can add to the lateral earth pressures, causing the equivalent fluid pressure values used in design to be exceeded. Floor Slabs and Exterior Flatwork The building floor slabs and exterior flatwork could be supported on reconditioned natural site soils or properly placed and compacted fill developed as outlined in the “Site Development” section of this report. A modulus of subgrade reaction (k value) of 125 pci could be used for design of floor slabs supported on the site lean clay or similar soils. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 11 Subgrade soils expected to receive floor slab and exterior flatwork concrete should be evaluated closely immediately prior to concrete placement. If areas of disturbed, wet and softened, or dry subgrade soils are encountered at that time, some reworking of those materials or removal/replacement procedures may be required. As a precaution, we recommend all partition walls supported above slabs-on-grade be constructed as floating walls to help reduce the potential for differential slab-to- foundation movement causing distress in upper sections of the buildings. A minimum 1½-inch void space is recommended beneath all floating walls. Special attention to stair systems, door framing, drywall installation and trim carpentry should be taken to isolate those elements from the floor slabs, allowing for some differential foundation to floor slab movement to occur without transmitting stresses to the overlying structures. Depending on the type of floor covering and floor covering adhesive used in finished slab-on-grade areas, a vapor barrier may be required immediately beneath the floor slabs to maintain flooring product manufacturer warranties. A vapor barrier would help reduce the transmission of moisture through the floor slabs, however, the unilateral moisture release caused by placing concrete on an impermeable surface can increase slab curl. The amount of slab curl can be reduced by careful selection of an appropriate concrete mix. Slab curl cannot be eliminated. We recommend the owner, architect and flooring contractor consider the performance of the slabs in conjunction with the proposed flooring products to help determine if a vapor barrier will be required and where best to position the vapor barrier in relation to the floor slab. Additional guidance and recommendations concerning slab on grade design can be found in American Concrete Institute (ACI) section 302. Pavements Site pavements could be supported directly on reconditioned natural site soils and/or properly placed and compacted fill developed as outlined above. The site lean clay would be subject to low remolded shear strength. A resistance value (R-value) of 5 was estimated for the site lean clay and used in the pavement section design. Traffic loading on site pavements is expected to consist of areas of low volumes of automobiles and light trucks as well as areas of higher light vehicle traffic volumes and occasional heavier Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 12 trash, delivery and emergency vehicle traffic. Equivalent 18-kip single axle loads (ESAL’s) were estimated for the quantity of site traffic anticipated. Two (2) general design classifications are outlined below in Table II. Standard duty pavements could be considered in automobile drive and parking areas. Heavy duty pavements should be considered for access drives and other areas of the site expected to receive higher traffic volumes or heavier trash, delivery and emergency truck traffic. Proofrolling of the pavement subgrades should be completed to help identify unstable areas. Areas which pump or deform excessively (greater than 1 inch) should be mended prior to asphalt, PCC or aggregate base course placement. Isolated areas of subgrade instability can be mended on a case-by-case basis. If more extensive areas of subgrade instability are observed and depending on the in-place moisture content of the subgrade soils immediately prior to paving, the time of year when construction occurs and other hydrologic conditions, overall stabilization of the subgrade soils may become necessary to develop a suitable paving platform. If required, we recommend consideration be given to stabilization of the pavement subgrades with Class C fly ash. With the increase in support strength developed by the chemical stabilization procedures, it is our opinion some credit for the stabilized zone could be included in the pavement section design, reducing the required thickness of overlying asphaltic concrete and aggregate base course. Chemical stabilization can also eliminate some of the uncertainty associated with attempting to pave during periods of inclement weather. Pavement section design options incorporating some structural credit for the chemically-stabilized subgrade soils are outlined below in Table II. TABLE II – PAVEMENT SECTION DESIGN Standard Duty Heavy Duty Option A – Composite Asphaltic Concrete (Grading S or SX) Aggregate Base (Class 5 or 6) 4” 6” 5” 8” Option B – Composite on Stabilized Subgrade Asphaltic Concrete (Grading S or SX) Aggregate Base (Class 5 or 6) Fly Ash Stabilized Subgrade 3” 4” 12” 4” 6” 12” Option C - Portland Cement Concrete Pavement PCCP 5” 6” Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 13 Asphaltic concrete should consist of a bituminous plant mix composed of a mixture of aggregate, filler, binders and additives (if required) meeting the design requirements of the City of Fort Collins. Aggregate used in the asphaltic concrete should meet specific gradation requirements such as Colorado Department of Transportation (CDOT) grading S (¾-inch minus) or SX (½-inch minus) specifications. Hot mix asphalt designed using “Superpave” criteria should be compacted to within 92 to 96% of the materials Maximum Theoretical Density. Aggregate base should be consistent with CDOT requirements for Class 5 or Class 6 aggregate base, placed in loose lifts not to exceed 9 inches thick and compacted to at least 95% of the materials standard Proctor maximum dry density. If chemical stabilization procedures will be completed, we recommend the addition of 13% Class ‘C’ fly ash based on component dry unit weights. A 12-inch thick stabilized zone should be constructed by thoroughly blending the fly ash with the in-place subgrade soils. Some “fluffing” of the finish subgrade level should be expected with the stabilization procedures. The blended materials should be adjusted in moisture content to within the range of ±2% of standard Proctor optimum moisture content and compacted to at least 95% of the material’s standard Proctor maximum dry density within two (2) hours of fly ash addition. For areas subjected to truck turning movements and/or concentrated and repetitive loading such as dumpster or truck parking and loading areas, we recommend consideration be given to the use of Portland cement concrete pavement with a minimum thickness of 6 inches. The concrete used for site pavements should be entrained with 4% to 8% air and have a minimum 28-day compressive strength of 4,200 psi and maximum water cement ratio of 0.44. Woven wire mesh or fiber entrained concrete should be considered to help in the control of shrinkage cracking. The proposed pavement section designs do not include an allowance for excessive loading conditions imposed by heavy construction vehicles or equipment. Heavily loaded concrete or other building material trucks and construction equipment can cause some localized distress to site pavements. The recommended pavement sections are minimums and periodic maintenance efforts should be expected. A preventative maintenance program can help increase the service life of site pavements. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 14 Utility Installation Bedding around utility pipelines should be placed in accordance with recommendations from the pipeline designer. Backfill soils placed above pipelines should consist of approved materials which are free from organic matter, debris and other objectionable materials. The on-site lean clay could be used as pipeline backfill. Lean clay pipeline backfill should be placed in maximum 9-inch loose lifts, adjusted to within ±2% of standard Proctor optimum moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density. Care will be needed to ensure utilities are not placed on or above disturbed or sloughed materials. Utility excavations will likely encounter overburden lean clay. Care will also be needed to develop stable side slopes in pipeline trenches excavated through soft lean clay. As such, we expect temporary shoring, bracing, or cutting of shallow slopes/ benches may be necessary in deeper excavations. Excavations should be sloped or shored in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. As a safety measure, it is recommended that vehicles and soil stockpiles be kept to a minimum lateral distance from the crest of the slope equal to no less than the slope height. Groundwater was encountered at depths ranging from approximately 12 to 14 feet below present site grade across a majority of the site. Shallower groundwater depths were observed in the proposed detention pond area. Utility excavations extended below groundwater elevation will require dewatering to facilitate proper construction. We expect dewatering procedures could be completed through open pumping procedures in sumps fed from ditches or sloped trench excavations. If deeper utility installation is required or if water bearing sand and gravel seams are exposed during excavation, limiting the size of open excavations and higher capacity sumps and pumps may be required. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 15 Corrosive Soil Characteristics Water-soluble sulfates (WSS) tests were completed on four (4) selected soil samples obtained from the site to help evaluate corrosive soil characteristics with respect to buried concrete. The samples evaluated include B-3 @ 4’, B-7 @ 2’, B-10 @ 2’ and B-12 @ 4’. WSS concentrations of less than 150 ppm were determined on all four samples. ACI classifies the measured concentrations in a “negligible risk” category for concrete sulfate attack; therefore Type I cement should be suitable for concrete members on and below grade. As an added precaution, Type I/II Portland cement could be considered for additional sulfate resistance of construction concrete. Foundation concrete should be designed in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. Site Grading We estimate maximum unretained cuts and fills of up to 5 feet in height will be required for general site development. Based on the materials encountered in the completed site borings, we recommend unretained cuts and fills be constructed to a 2(H) to 1(V) or flatter slope configuration. Shallower slopes are often desirable to help facilitate revegetation efforts. Fill soils should be placed and compacted as outlined in the ‘Site Development’ section of this report. Proper drainage should be provided and maintained around all cuts, fills, structures and pavement areas. Special attention should be given to channeling or routing drainage around and away from sloped areas. Excessive or uncontrolled surface and subsurface drainage could lead to erosion and poor site fill performance and/or slope failure. All disturbed areas should be protected from erosion by revegetation or other appropriate methods. Areas of concentrated drainage should be protected by use of rip rap or other energy dissipation/protective procedures. Detention Pond Construction Two (2) soil borings extended to a depth of approximately 15 feet below present site grade were completed in the area of a proposed detention pond. The materials encountered in the completed detention pond borings consisted of approximately 3 to 6 Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 16 inches of vegetation and topsoil underlain by light brown to brown/reddish brown sandy lean clay. The lean clay varied from medium stiff to very stiff in terms of consistency and extended to the bottom of borings B-17 and B-18 at a depth of approximately 15 feet below present site grade. When checked about 5 days after completion of drilling, groundwater was measured at depths of approximately 10 and 4 feet below ground surface at boring locations B-17 and B-18 respectively. Boring B-18 was completed near an existing storm water detention pond/ditch. Recent rain events may have surcharged groundwater levels in the area of the existing detention pond/ditch improvement, resulting in shallower than anticipated groundwater level measurements. Longer-term observation of groundwater levels would be required in wells which are cased and sealed from the influence of surface water to better define seasonal high groundwater levels and possible fluctuations in groundwater levels over time. Drainage Positive drainage is imperative for satisfactory long-term performance of the proposed buildings and associated site improvements. We recommend positive drainage be developed away from the structures during construction and maintained throughout the life of the site improvements with a minimum of 10% fall in the first 10 feet away from the buildings. Shallower slopes could be considered in hardscape areas. In the event that some settlement of the backfill soils occurs adjacent to the buildings, the original grade and associated positive drainage outlined above should be immediately restored. Care should be taken in the planning of landscaping to avoid features which could result in the fluctuation of the moisture content of the foundation bearing and flatwork subgrade soils. We recommend watering systems be placed a minimum of 5 feet away from the perimeter of the site structures and be designed to discharge away from all site improvements. Gutter systems should be considered to help reduce the potential for water ponding adjacent to the buildings with the gutter downspouts, roof drains or scuppers extended to discharge a minimum of 5 feet away from structural and flatwork elements. Water which is allowed to pond adjacent to site improvements can result in unsatisfactory performance of those improvements over time. Geotechnical Subsurface Exploration Report HTP North Retail and Office Center Fort Collins, Colorado Soilogic # 15-1138 17 GENERAL COMMENTS This report was prepared based upon the data obtained from the completed site exploration, laboratory testing, engineering analysis and any other information discussed. The completed borings provides an indication of subsurface conditions at the boring locations only. Variations in subsurface conditions can occur in relatively short distances away from the borings. This report does not reflect any variations which may occur across the site or away from the borings. If variations in the subsurface conditions anticipated become evident, the geotechnical engineer should be notified immediately so that further evaluation can be completed and when warranted, alternative recommendations provided. The scope of services for this project does not include either specifically or by implication any biological or environmental assessment of the site or identification or prevention of pollutants or hazardous materials or conditions. Other studies should be completed if concerns over the potential of such contamination or pollution exist. The geotechnical engineer should be retained to review the plans and specifications so that comments can be made regarding the interpretation and implementation of our geotechnical recommendations in the design and specifications. The geotechnical engineer should also be retained to provide testing and observation services during construction to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with the generally accepted standard of care for the profession. No warranties express or implied, are made. The conclusions and recommendations contained in this report should not be considered valid in the event that any changes in the nature, design or location of the project as outlined in this report are planned, unless those changes are reviewed and the conclusions of this report modified and verified in writing by the geotechnical engineer. LOG OF BORING B-1 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 CS 11 17.2 106.3 9000+ 0.3% 800 - - - stiff - 4 - 5 CS 18 14.6 118.7 8000 None <500 - - - - 6 - 7 - 8 - 9 - 10 CS 12 15.3 115.9 4000 - - - - - - 11 - 12 - 13 - 14 - SP-GP SAND AND GRAVEL - red/brn, loose 15 CS 14 13.1 118.0 N/A - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-2 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 medium stiff to stiff - 4 Varies to Clayey Sand in Places - 5 CS 13 13.5 119.2 8000 None <500 - - - - 6 - 7 - 8 - 9 - 10 CS 14 16.9 115.8 6000 None <500 - - - - 11 - 12 - 13 - 14 - 15 CS 8 17.9 108.8 <500 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-3 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 CS 10 18.7 107.6 7000 - - - - - medium stiff to stiff - 4 - 5 CS 13 11.9 122.3 9000+ None <500 29 14 73.2% - 6 - 7 - 8 - 9 - 10 CS 18 15.9 117.8 9000+ 0.3% 800 - - - - 11 - 12 - 13 - 14 - 15 CS 13 14.2 119.9 4000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-4 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 medium stiff to stiff - 4 - 5 CS 13 12.0 123.7 8500 None <500 - - - - 6 - 7 - 8 - 9 - 10 CS 9 15.7 113.8 9000+ - - - - - - 11 - 12 - 13 - 14 - 15 CS 18 14.8 121.8 7000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-5 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 CS 10 17.8 105.0 9000+ None <500 - - - soft to stiff - 4 - 5 CS 4 16.9 103.4 9000+ - - - - - - 6 - 7 - 8 - 9 - 10 CS 11 17.2 108.6 5000 - - - - - - 11 - 12 - 13 - 14 - SP-GP SAND AND GRAVEL - red/brn, med dnse 15 CS 29 9.0 134.1 N/A - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-6 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 medium stiff to stiff - 4 - 5 CS 14 13.1 124.2 9000+ None <500 - - - - 6 - 7 - 8 - 9 - 10 CS 9 16.0 119.9 6500 None <500 - - - - 11 - 12 - 13 - SP-GP SAND AND GRAVEL 14 reddish brown, loose - 15 CS 11 23.3 105.2 9000+ - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-7 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 CS 15 16.0 109.9 9000+ None <500 - - - medium stiff to stiff - 4 - 5 CS 13 20.2 104.9 7000 - - 34 17 77.0% - 6 - 7 - 8 - 9 - 10 CS 10 14.1 118.1 8000 - - - - - - 11 - 12 - 13 - 14 - SM SILTY SAND WITH GRAVEL - red brn 15 CS 15 11.3 117.1 3000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-8 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 medium stiff to very stiff - 4 - 5 CS 22 21.0 105.6 7000 None <500 - - - - 6 - 7 - 8 - 9 - 10 CS 9 26.1 98.0 <500 None <500 - - - - 11 - 12 - 13 - 14 - 15 CS 13 13.2 110.6 9000+ - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-9 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 medium stiff to stiff - 4 - 5 CS 12 15.4 112.7 9000+ None <500 - - - - 6 - 7 - 8 - 9 - 10 CS 13 22.5 99.3 2000 None <500 - - - - 11 - 12 - 13 - 14 - 15 CS 8 16.7 112.2 5000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-10 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 CS 16 15.2 104.5 9000+ 0.1% 750 - - - medium stiff to stiff - 4 - 5 CS 6 16.4 110.4 6500 - - - - - - 6 - 7 - 8 - 9 - 10 CS 6 23.5 95.7 <500 - - - - - - 11 - 12 - 13 - 14 - 15 CS 13 17.8 106.6 5000 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-11 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 CS 9 21.4 103.0 7000 None <500 - - - medium stiff to stiff - 4 - 5 CS 10 11.4 125.1 9000+ - - - - - - 6 - 7 - 8 - 9 - 10 CS 8 18.3 112.3 3500 - - - - - - 11 - 12 - 13 - 14 - 15 CS 13 13.3 125.9 9000+ - - - - - - 16 - 17 - 18 - 19 - 20 CS 50/7 18.9 107.9 9000+ - - - - - CLAYSTONE - brown/grey/rust 21 hard to very hard - 22 - 23 - 24 - 25 CS 50/5 18.5 110.1 9000+ - - - - - BOTTOM OF BORING 25' - LOG OF BORING B-12 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 soft to medium stiff - 4 - 5 CS 7 13.5 108.4 9000+ None <500 29 16 63.3% - 6 - 7 - 8 - 9 - 10 CS 3 20.0 109.9 1500 None <500 - - - - 11 - 12 - 13 - 14 - 15 CS 9 20.0 110.5 4000 - - - - - - 16 - 17 - 18 - 19 - 20 CS 5 NR - - - - - - - - 21 - 22 - CLAYSTONE 23 brown/grey/rust - very hard 24 - 25 CS 50/5 18.1 113.5 9000+ - - - - - BOTTOM OF BORING 25' - LOG OF BORING B-13 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 medium stiff to stiff - 4 - 5 CS 10 11.5 123.4 9000+ - - - - - - 6 - 7 - 8 - 9 - 10 CS 18 25.1 98.0 5000 None <500 - - - - 11 - 12 - 13 - 14 - 15 CS 12 11.5 123.4 7000 - - - - - - 16 - 17 - 18 - 19 - CLAYSTONE 20 CS 50/6 18.2 123.2 9000+ - - - - - brown/grey/rust - very hard 21 - 22 - 23 - 24 - 25 CS 50/4 19.5 95.4 9000+ - - - - - BOTTOM OF BORING 25' - LOG OF BORING B-14 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 200&500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 CS 8 17.9 112.1 9000+ None @ 0.2k <200 - - - medium stiff to stiff - 4 Varies to Clayey Sand in Places - 5 CS 10 11.3 115.4 9000+ - - - - - - 6 - 7 - 8 - 9 - 10 CS 12 19.8 102.7 5000 - - - - - BOTTOM OF BORING 10' - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-15 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 200&500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 CS 16 16.2 110.9 9000+ None @ 0.2k <200 - - - stiff - 4 - 5 CS 17 12.4 118.2 9000+ 0.1% @ 0.5k 700 - - - - 6 - 7 - 8 - 9 - 10 CS 13 17.1 111.6 5500 - - - - - BOTTOM OF BORING 10' - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-16 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 200&500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 CS 10 15.9 110.7 7500 None @ 0.2k <200 - - - medium stiff to stiff - 4 - 5 CS 14 18.3 108.3 8500 None @ 0.5k <500 - - - - 6 - 7 - 8 - 9 - 10 CS 6 25.5 95.0 3500 - - - - - BOTTOM OF BORING 10' - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-17 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 medium stiff to very stiff - 4 - 5 CS 19 13.4 120.0 9000+ - - - - - - 6 - 7 - 8 - 9 - 10 CS 10 19.5 104.9 5500 - - - - - - 11 - 12 - 13 - 14 - 15 CS 6 32.4 81.0 3500 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-18 1/1 CME 55 4" CFA Manual BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3 - 6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - brown to reddish brown 3 medium stiff - 4 - 5 CS 9 17.5 102.5 2000 - - 27 15 59.5% - 6 - 7 - 8 - 9 - 10 CS 7 21.9 105.0 500 - - - - - - 11 - 12 - 13 - 14 - 15 CS 7 29.9 79.8 <500 - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 106.3 pcf Sample Description: Brown Sandy Lean Clay (CL) Sample ID: B-1 @ 2' HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY 0.3% 800 psf Initial Moisture Final Moisture % Swell @ 500 psf Swell Pressure 17.2% 21.1% -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 118.7 pcf Final Moisture 16.1% % Swell @ 500 psf None Swell Pressure <500 psf Sample ID: B-1 @ 4' Sample Description: Reddish Brown Sandy Lean Clay (CL) Initial Moisture 14.6% HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 119.2 pcf Final Moisture 13.4% % Swell @ 500 psf None Swell Pressure <500 psf Sample ID: B-2 @ 4' Sample Description: Reddish Brown Sandy Lean Clay/Clayey Sand (CL-SC) Initial Moisture 13.5% HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 115.8 pcf Final Moisture 17.4% % Swell @ 500 psf None Swell Pressure <500 psf Sample ID: B-2 @ 9' Sample Description: Light Brown Sandy Lean Clay (CL) Initial Moisture 16.9% HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit 29 Plasticity Index 14 % Passing #200 73.2% Dry Density 122.3 pcf Final Moisture 12.7% % Swell @ 500 psf None Swell Pressure <500 psf Sample ID: B-3 @ 4' Sample Description: Brown Lean Clay with Sand (CL) Initial Moisture 11.9% HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 117.8 pcf Final Moisture 16.8% % Swell @ 500 psf 0.3% Swell Pressure 800 psf Sample ID: B-3 @ 9' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 15.9% HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 123.7 pcf Final Moisture 13.6% % Swell @ 500 psf None Swell Pressure <500 psf Sample ID: B-4 @ 4' Sample Description: Reddish Brown Sandy Lean Clay (CL) Initial Moisture 12.0% HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 105.0 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-5 @ 2' Sample Description: Reddish Brown Sandy Lean Clay (CL) Initial Moisture 17.8% Final Moisture 20.6% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 124.2 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-6 @ 4' Sample Description: Reddish Brown Sandy Lean Clay (CL) Initial Moisture 13.1% Final Moisture 13.9% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 119.9 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-6 @ 9' Sample Description: Light Brown Sandy Lean Clay (CL) Initial Moisture 16.0% Final Moisture 14.5% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 109.9 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-7 @ 2' Sample Description: Reddish Brown Sandy Lean Clay (CL) Initial Moisture 16.0% Final Moisture 18.5% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 105.6 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-8 @ 4' Sample Description: Reddish Brown Sandy Lean Clay (CL) Initial Moisture 21.0% Final Moisture 19.3% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 98.0 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-8 @ 9' Sample Description: Light Brown Sandy Lean Clay (CL) Initial Moisture 26.1% Final Moisture 25.6% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 112.7 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-9 @ 4' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 15.4% Final Moisture 16.1% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 99.3 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-9 @ 9' Sample Description: Light Brown Sandy Lean Clay (CL) Initial Moisture 22.5% Final Moisture 20.8% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 104.5 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-10 @ 2' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 15.2% Final Moisture 19.0% % Swell @ 200 psf 0.1% Swell Pressure 750 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 103.0 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-11 @ 2' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 21.4% Final Moisture 21.4% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit 29 Plasticity Index 16 % Passing #200 63.3% Dry Density 108.4 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-12 @ 4' Sample Description: Reddish Brown Sandy Lean Clay (CL) Initial Moisture 13.5% Final Moisture 14.2% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 109.9 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-12 @ 9' Sample Description: Reddish Brown Sandy Lean Clay (CL) Initial Moisture 20.0% Final Moisture 20.4% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 98.0 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-13 @ 9' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 25.1% Final Moisture 24.0% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 112.1 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-14 @ 2' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 17.9% Final Moisture 18.8% % Swell @ 200 psf None Swell Pressure <200 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 110.9 pcf Final Moisture 18.2% % Swell @ 200 psf None Swell Pressure <200 psf Sample ID: B-15 @ 2' Sample Description: Reddish Brown Sandy Lean Clay (CL) Initial Moisture 16.2% HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 118.2 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-15 @ 4' Sample Description: Reddish Brown Sandy Lean Clay (CL) Initial Moisture 12.4% Final Moisture 15.0% % Swell @ 500 psf 0.1% Swell Pressure 700 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 110.7 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-16 @ 2' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 15.9% Final Moisture 19.8% % Swell @ 200 psf None Swell Pressure <200 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 108.3 pcf HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-16 @ 4' Sample Description: Brown Sandy Lean Clay (CL) Initial Moisture 18.3% Final Moisture 20.1% % Swell @ 500 psf None Swell Pressure <500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Resistivity (ohms-cm) Corrosion Condition < 2,300 very aggressive 2,300- 5,000 moderately aggressive 5,000- 10,000 slightly aggressive > 10,000 non- aggressive Aggressivity Aggressivity pH Range Acid/Base to Lead to Iron and Steel < 4 extremely acidic very aggressive very aggressive 4.0- 4.5 very acidic very aggressive very aggressive 4.5- 5.0 acidic slightly aggressive very aggressive 5.0-6.0 slightly acidic slightly aggressive very aggressive 6.0- 6.5 slightly acidic slightly aggressive aggressive 6.5- 7.5 neutral non- aggressive non- aggressive 7.5- 8.5 slightly alkaline non- aggressive non- aggressive > 8.5 very alkaline very aggressive doubtful Exposure In water (ppm) Negligible < 150 Moderate 150 to 1500 Severe 1500 to 10000 Very Severe > 10000 ACI 318-11 " Corrosion of Metals in the Underground and Underground Telephone Plant" by George Schick, Bell Telephone Laboratories In soil, percent by weight < 0.1 (Level of Sulfate Attack of Concrete Exposed to Soils) CORROSIVE SOIL CHARACTERISTICS (Degree of Aggression for Corrosion of Buried Ferrous Metals Exposed to Soil) (Degree of Aggression for Corrosion of Buried Lead, Iron and Steel Exposed to Soil) 0.1 to 0.2 0.2 to 2.0 > 2.0 WATER SOLUBLE SULFATES Concentration of soluble sulfates expressed as SO4 SOIL RESISTIVITY SOIL pH UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Soil Classification Group Symbol Group NameB Clean Gravels Cu ! 4 and 1 " Cc " 3E GW Well graded gravelF Less than 5% finesC Cu < 4 and/or 1 > Cc > 3E GP Poorly graded gravelF Fines classify as ML or MH GM Silty gravelF,G, H Coarse Grained Soils More than 50% retained on No. 200 sieve Gravels More than 50% of coarse fraction retained on No. 4 sieve Gravels with Fines More than 12% finesC Fines classify as CL or CH GC Clayey gravelF,G,H Clean Sands Cu ! 6 and 1 " Cc " 3E SW Well graded sandI Less than 5% finesD Cu < 6 and/or 1 > Cc > 3E SP Poorly graded sandI Fines classify as ML or MH SM Silty sandG,H,I Sands 50% or more of coarse fraction passes No. 4 sieve Sands with Fines More than 12% finesD Fines classify as CL or CH SC Clayey sandG,H,I Silts and Clays PI > 7 and plots on or above “A” lineJ CL Lean clayK,L,M Liquid limit less than 50 Inorganic PI < 4 or plots below “A” lineJ ML SiltK,L,M Liquid limit - oven dried Organic clayK,L,M,N Fine-Grained Soils 50% or more passes the No. 200 sieve Organic Liquid limit - not dried < 0.75 OL Organic siltK,L,M,O Inorganic PI plots on or above “A” line CH Fat clayK,L,M Silts and Clays Liquid limit 50 or more PI plots below “A” line MH Elastic siltK,L,M Organic Liquid limit - oven dried Organic clayK,L,M,P Liquid limit - not dried < 0.75 OH Organic siltK,L,M,Q Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-in. (75-mm) sieve B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name. C Gravels with 5 to 12% fines require dual symbols: GW-GM well graded gravel with silt, GW-GC well graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay. D Sands with 5 to 12% fines require dual symbols: SW-SM well graded sand with silt, SW-SC well graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay E Cu = D60/D10 Cc = GENERAL NOTES DRILLING & SAMPLING SYMBOLS: SS: Split Spoon - 1⅜" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger ST: Thin-Walled Tube – 2.5" O.D., unless otherwise noted PA: Power Auger RS: Ring Sampler - 2.42" I.D., 3" O.D., unless otherwise noted HA: Hand Auger CS: California Barrel - 1.92" I.D., 2.5" O.D., unless otherwise noted RB: Rock Bit BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary The number of blows required to advance a standard 2-inch O.D. split-spoon sampler (SS) the last 12 inches of the total 18-inch penetration with a 140-pound hammer falling 30 inches is considered the “Standard Penetration” or “N-value”. For 2.5” O.D. California Barrel samplers (CB) the penetration value is reported as the number of blows required to advance the sampler 12 inches using a 140-pound hammer falling 30 inches, reported as “blows per inch,” and is not considered equivalent to the “Standard Penetration” or “N-value”. WATER LEVEL MEASUREMENT SYMBOLS: WL: Water Level WS: While Sampling WCI: Wet Cave in WD: While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB: After Boring ACR: After Casing Removal Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-term observations. DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency. FINE-GRAINED SOILS COARSE-GRAINED SOILS BEDROCK (CB) Blows/Ft. (SS) Blows/Ft. Consistency (CB) Blows/Ft. (SS) Blows/Ft. Relative Density (CB) Blows/Ft. (SS) Blows/Ft. Consistency < 3 0-2 Very Soft 0-5 < 3 Very Loose < 24 < 20 Weathered 3-5 3-4 Soft 6-14 4-9 Loose 24-35 20-29 Firm 6-10 5-8 Medium Stiff 15-46 10-29 Medium Dense 36-60 30-49 Medium Hard 11-18 9-15 Stiff 47-79 30-50 Dense 61-96 50-79 Hard 19-36 16-30 Very Stiff > 79 > 50 Very Dense > 96 > 79 Very Hard > 36 > 30 Hard RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY Descriptive Terms of Other Constituents Percent of Dry Weight Major Component of Sample Particle Size Trace < 15 Boulders Over 12 in. (300mm) With 15 – 29 Cobbles 12 in. to 3 in. (300mm to 75 mm) Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75 mm) Sand Silt or Clay #4 to #200 sieve (4.75mm to 0.075mm) Passing #200 Sieve (0.075mm) RELATIVE PROPORTIONS OF FINES PLASTICITY DESCRIPTION Descriptive Terms of Other Constituents Percent of Dry Weight Term Plasticity Index Trace With Modifiers < 5 5 – 12 > 12 Non-plastic Low Medium High 0 1-10 11-30 30+ F If soil contains ! 15% sand, add “with sand” to group name. G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM. HIf fines are organic, add “with organic fines” to group name. I If soil contains ! 15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant. L If soil contains ! 30% plus No. 200 predominantly sand, add “sandy” to group name. M If soil contains ! 30% plus No. 200, predominantly gravel, add “gravelly” to group name. N PI ! 4 and plots on or above “A” line. O PI < 4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line. 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 5 Days After Drilling 4' USCS Sampler Atterberg Limits Start Date 6/11/2015 Auger Type: During Drilling 15' Finish Date 6/11/2015 Hammer Type: After Drilling 15' HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 5 Days After Drilling WCI @ 10' USCS Sampler Atterberg Limits Start Date 6/11/2015 Auger Type: During Drilling 14' Finish Date 6/11/2015 Hammer Type: After Drilling 14' HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 5 Days After Drilling Dry to 9' USCS Sampler Atterberg Limits Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 5 Days After Drilling Dry to 9' USCS Sampler Atterberg Limits Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 5 Days After Drilling Dry to 9' USCS Sampler Atterberg Limits Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 5 Days After Drilling 12' USCS Sampler Atterberg Limits Start Date 6/11/2015 Auger Type: During Drilling 18' Finish Date 6/11/2015 Hammer Type: After Drilling 18' HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 5 Days After Drilling 12' USCS Sampler Atterberg Limits Start Date 6/11/2015 Auger Type: During Drilling 15' Finish Date 6/11/2015 Hammer Type: After Drilling 15' HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling 19' Finish Date 6/11/2015 Hammer Type: After Drilling 19' Surface Elev. - Field Personnel: 5 Days After Drilling 13' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None CLAYSTONE - rust/olive/brown, weathered Surface Elev. - Field Personnel: 5 Days After Drilling 13' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 5 Days After Drilling 12' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 5 Days After Drilling Dry to 15' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 5 Days After Drilling Dry to 15' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling 15' Finish Date 6/11/2015 Hammer Type: After Drilling 15' CLAYSTONE - rust/olive/brown, weathered Surface Elev. - Field Personnel: 5 Days After Drilling 13' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 5 Days After Drilling 14' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 5 Days After Drilling 14' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 5 Days After Drilling 14' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling None Finish Date 6/11/2015 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 5 Days After Drilling 14' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 HTP NORTH RETAIL AND OFFICE CENTER HARMONY TECHNOLOGY PARK, FORT COLLINS, COLORADO Project # 15-1138 June 2015 Sheet Drilling Rig: Water Depth Information Start Date 6/11/2015 Auger Type: During Drilling 15' Finish Date 6/11/2015 Hammer Type: After Drilling 15' Surface Elev. - Field Personnel: 5 Days After Drilling 14' USCS Sampler Atterberg Limits