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Home My WebLink AboutPROSPECT SPORTS CLUB - FDP240002 - SUBMITTAL DOCUMENTS - ROUND 2 - Geotechnical (Soils) ReportGEOTECHNICAL SUBSURFACE EXPLORATION REPORT PROSPECT PROPERTIES BASKETBALL FACILITY LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO SOILOGIC # 22-1426 December 19, 2022 Soilogic, Inc. 3522 Draft Horse Court • Loveland, CO 80538 • (970) 535-6144 December 19, 2022 RB+B Architects, Inc. 315 E. Mountain Avenue, Suite 100 Fort Collins, Colorado 80524 Attn: Ms. Rebecca Spears Re: Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 Ms. Spears: Soilogic, Inc. (Soilogic) personnel have completed the geotechnical subsurface exploration you requested for the proposed Prospect Properties Basketball Facility to be constructed on Lot 5 of the Prospect Park East, P.U.D. in Fort Collins, Colorado. The results of our subsurface exploration and pertinent geotechnical engineering recommendations are included with this report. In summary, the subsurface materials encountered in the completed site borings consisted of a thin mantle of vegetation and topsoil underlain by brown/beige/rust lean clay with varying amounts of sand. The near-surface portion of this material was somewhat mottled in color and was identified as possible overlot grading fill material which may been placed to develop existing site grades, and appeared to extend to depths of about 2 to 3 feet below ground surface, where it was underlain by apparently-natural lean clay with sand. The possible existing fill and/or natural lean clay contained minor amounts of gravel, varied from medium stiff to hard in terms of consistency, exhibited no to high swell potential at in-situ moisture and density conditions and extended to depths ranging from approximately 3½ to 7 feet below ground surface, where it was underlain by brown/rust sand with silt and gravel. The sand and gravel varied from medium dense to very dense in terms of relative density, would be expected to be non-expansive or possess low swell potential based on the physical properties and engineering characteristics of the material, and extended to the bottom of all borings at depths between approximately 10 and 15 feet below present ground surface. Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 2 Groundwater was encountered at depths between 7 and 10 feet below ground surface in borings B-1 through B-9, while boring B-10 remained dry to the depth explored (about 10 feet below ground surface) at the time of drilling. When checked six (6) days after the completion of drilling, a dry cave-in was measured at a depth of about 6½ feet below ground surface in boring B-1, groundwater or wet cave-ins were measured at depths between about 6 and 8½ feet below ground surface in borings B-2 through B-9, and boring B-10 remained dry to the depth explored at that time. Based on the subsurface conditions encountered in the completed site borings, results of laboratory testing and type of construction proposed, it is our opinion the proposed basketball facility building could be constructed with conventional spread footing foundations and floor slabs bearing directly on a mat of properly placed and compacted overexcavation/backfill due to the presence of possible existing fill and expansive near- surface lean clay soils. Similar overexcavation/backfill methods are recommended to develop low volume-change (LVC) pavement support. The reconditioned site lean clay soils appear suitable for use as LVC fill and overexcavation/backfill to develop the site and could be used for support of the building floor slabs and site pavements. The overexcavation/backfill procedures will help develop LVC-potential foundation bearing/ floor slab and pavement support, reducing the potential for total and differential movement of those supported elements subsequent to construction. The risk of some movement cannot be eliminated. Other opinions and recommendations concerning design criteria and construction details for the proposed site improvements are included with this report. Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 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 provide any further assistance, please do not hesitate to contact us. Very Truly Yours, Soilogic, Inc. Reviewed by: Darrel DiCarlo, P.E. Alec Kaljian, P.E. Senior Project Engineer Project Engineer 12/19/2022 12/19/2022 Soilogic, Inc. 3522 Draft Horse Court • Loveland, CO 80538 • (970) 535-6144 GEOTECHNICAL SUBSURFACE EXPLORATION REPORT PROSPECT PROPERTIES BASKETBALL FACILITY LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO SOILOGIC # 22-1426 December 19, 2022 INTRODUCTION This report contains the results of the completed geotechnical subsurface exploration for the proposed Prospect Properties Basketball Facility to be constructed on Lot 5 of the Prospect Park East, P.U.D., located at 1601 Sharp Point Drive 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 proposed automobile wash building foundations and support of floor slabs and site pavements. The conclusions and recommendations outlined in this report are based on the results of the completed field and laboratory testing and our experience with subsurface conditions in this area. PROPOSED CONSTRUCTION Based on the provided site plan, we understand the proposed building will be a single-story concrete masonry unit (CMU) and/or steel-frame structure constructed as slab-on-grade encompassing a plan area of approximately 40,000 square feet. Foundation loads for the structure are expected to be light to moderate, with continuous wall loads on the order of 4 to 6 kips per lineal foot and individual column loads less than 150 kips. Paved drive lane and parking areas are anticipated on the east side of the building as part of the proposed site improvements. Traffic loading on site pavements is expected to consist of relatively low volumes of light passenger vehicles, with occasional delivery and trash truck traffic. Small grade changes are anticipated to develop finish site grades in the building and pavement areas. SITE DESCRIPTION The development property is identified as Lot 5 of the Prospect Park East, P.U.D., located at 1601 Sharp Point Drive in Fort Collins, Colorado. At the time of our site exploration, the lot was vacant/undeveloped. The ground surface across the site contained a moderate Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 2 growth of native grass vegetation and was observed to be relatively level within a majority of the approximate building footprint. The maximum difference in ground surface elevation across most of the building footprint is estimated to be on the order of about two (2) feet or less based upon review of a provided topographic survey of the property. A small grove of small to medium-sized diameter deciduous trees was noted in a slight depression in the south-central portion of the property, within the eastern portion of the proposed building footprint. This area appeared to be two (2) to three (3) feet lower in elevation than the rest of the approximate area of construction. Evidence of prior building construction was not observed in the proposed construction area at the time of our exploration. The Prospect Ponds, which appear to consist of reclaimed aggregate mining water impoundments, were also noted to the east of the property. SITE EXPLORATION Field Exploration To develop subsurface information for the proposed site improvements, a total of ten (10) soil borings were completed. Eight (8) borings were advanced in the area of the proposed gym building to a depth of approximately 15 feet below ground surface. Two (2) additional borings were completed in proposed pavement areas to a depth of approximately 10 feet below ground surface. The boring locations were established in the field by Soilogic personnel based on a provided site plan, by pacing and estimating angles and distances from identifiable site references. A diagram indicating the approximate boring locations is included with this report. The boring locations indicated on the attached diagram should be considered accurate only to the degree implied by the methods used to make the field measurements. Graphic logs of each of the auger borings are also included. The test holes were advanced using 4-inch diameter continuous-flight auger, powered by a truck-mounted CME-45 drill rig. Samples of the subsurface materials were obtained at regular intervals using California and split-barrel sampling procedures in general accordance with ASTM specification D-1586. As part of the D-1586 sampling procedure, standard sampling barrels are driven into the substrata using a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the samplers a distance of 12 inches is recorded and helpful in estimating the consistency or relative density of the Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 3 soils 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 were visually 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. 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/bedrock 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/bedrock characteristics. Atterberg limits tests are used to determine soil/bedrock plasticity. The percent passing the #200 size sieve (-200 wash test) is used to determine the percentage of fine-grained materials (clay and silt) in a sample. Swell/consolidation tests are performed to evaluate soil/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 laboratory testing, water soluble sulfate (WSS) tests are being completed on two (2) selected samples of the lean clay soils to help evaluate corrosive soil characteristics with respect to buried concrete and results will be provided under separate cover when they become available. SUBSURFACE CONDITIONS In summary, the subsurface materials encountered in the completed site borings consisted of a thin mantle of vegetation and topsoil underlain by brown/beige/rust lean clay with varying amounts of sand. The near-surface portion of this material was somewhat mottled in color and was identified as possible overlot grading fill material which may been placed to develop existing site grades, and appeared to extend to depths of about 2 to 3 feet below Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 4 ground surface, where it was underlain by apparently-natural lean clay with sand. The possible existing fill and/or natural lean clay contained minor amounts of gravel, varied from medium stiff to hard in terms of consistency, exhibited no to high swell potential at in-situ moisture and density conditions and extended to depths ranging from approximately 3½ to 7 feet below ground surface, where it was underlain by brown/rust sand with silt and gravel. The sand and gravel varied from medium dense to very dense in terms of relative density, would be expected to be non-expansive or possess low swell potential based on the physical properties and engineering characteristics of the material, and extended to the bottom of all borings at depths between approximately 10 and 15 feet below present ground surface. The stratigraphy on the included boring logs represents the approximate location of changes in soil types. Actual changes may be more gradual than those indicated. Groundwater was encountered at depths between 7 and 10 feet below ground surface in borings B-1 through B-9, while boring B-10 remained dry to the depth explored (about 10 feet below ground surface) at the time of drilling. When checked six (6) days after the completion of drilling, a dry cave-in was measured at a depth of about 6½ feet below ground surface in boring B-1, groundwater or wet cave-ins were measured at depths between about 6 and 8½ feet below ground surface in borings B-2 through B-9, and boring B-10 remained dry to the depth explored at that time. Groundwater levels are recorded 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. Groundwater levels would be expected to be directly impacted by water levels in the Prospect Ponds. 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/trapped water can also vary over time. Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 5 ANALYSIS AND RECOMMENDATIONS General The possible existing fill and/or natural lean clay soils encountered near-surface in the borings drilled across this site exhibited variable swell potential (ranging from low to high) at in-situ moisture and density conditions. Total and differential heaving of site improvements placed directly on or immediately above the existing fill and/or expansive lean clay soil would be expected as the moisture content of those materials increases subsequent to construction. Based on the subsurface conditions encountered in the completed site borings, results of laboratory testing and type of construction proposed, it is our opinion overexcavation/ backfill procedures could be completed beneath the building foundations and floor slabs to reduce the potential for movement of those supported elements subsequent to construction. The risk of some movement cannot be eliminated. Recommendations concerning overexcavation/backfill procedures to redevelop low volume change (LVC) foundation and floor slab support for the building are outlined below. If some structural and floor slab movement and associated distress cannot be tolerated, drilled pier foundations and structural floor systems should be employed. Drilled pier foundations and structural floor systems would offer an effective system for mitigating the potential for total and differential movement of the building foundation and floor slab subsequent to construction in the expansive soil environment. Drilled piers would anchor the building into bedrock underlying the site, significantly reducing the potential for movement of the structure. Deeper subsurface exploration would be required to develop soil design parameters for use in drilled pier design. If drilled pier foundations are to be used, structural flooring systems or overexcavation/backfill procedures to develop LVC floor slab subgrades would be required. Recommendations concerning the design and construction of drilled pier foundations and structural flooring systems can be provided at your request. Groundwater was measured in the open boreholes at depths ranging from approximately 6 to 8½ feet below ground surface when checked six (6) days after the completion of drilling. Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 6 Although not anticipated, dewatering of removal excavations as part of the overexcavation/ backfill procedures outlined above may be required to facilitate proper construction. Recommendations concerning dewatering procedures (if necessary) are included with this report. Foundation Bearing and Subgrade Development To develop low-volume-change (LVC) potential foundation and floor slab support, and reduce the potential for total and differential movement of the building foundation and floor slab subsequent to construction, we recommend a zone of reconditioned soil be developed beneath those supported elements. The reconditioned mat will provide a zone of material immediately beneath the building foundation and floor slab which will have low potential for volume change subsequent to construction. The LVC mat and surcharge loads placed on the underlying soils/bedrock by the reconditioned mat would reduce the potential for total and differential movement of the supported improvements subsequent to construction. The reconditioned zone would also assist in distributing movement in the event that some swelling of the materials underlying the reconditioned zone occurs. The overexcavation zone should include the entire building footprint and extend to natural, undisturbed, moist lean clay and/or sand and gravel with no to low swell potential, anticipated to be encountered at depths within about three (3) feet of intended foundation bearing elevations. The overexcavation area should also extend a minimum of two (2) feet laterally beyond the exterior edges of the building footprint. Since movement of site pavements is generally considered to be less consequential than structural and floor slab movement, it is our opinion the overexcavation zone beneath site pavements could be reduced to a minimum of 24 inches below finish subgrade levels, with the understanding that some movement of site pavements may occur subsequent to construction. The 24-inch LVC zone beneath site pavements could be developed through any combination of overexcavation/backfill procedures, subgrade reconditioning and new fill placement. Soils used as overexcavation/backfill should consist of approved materials free from organic matter, debris and other objectionable materials. Based on results of the completed Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 7 laboratory testing, it is our opinion the possible existing fill and/or natural site lean clay could be used as overexcavation/backfill provided care is taken to develop the proper moisture content in those materials at the time of placement and compaction. Essentially- granular structural fill materials could be used below the building footprint where overexcavation will remove the existing fill and expansive lean clay soil to natural underlying soil with no to low swell potential, but should not be used as backfill below site pavements where only limited overexcavation will be completed due to the ability of these materials to pond and transmit water. All existing topsoil and vegetation should be removed from the proposed building, pavement and any proposed fill areas. After stripping and completing all cuts and overexcavation procedures and prior to placement of any new fill or overexcavation/ backfill, we recommend the exposed subgrades 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 scarified lean soils should be adjusted to be within the range of -1 to +3% of standard Proctor optimum moisture content at the time of compaction, while scarified sand and gravel soils should be adjusted to within the range of ±2% of the materials standard Proctor optimum moisture content. Fill and overexcavation/backfill materials consisting of the site lean clay, sand and gravel and/or similar soils should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted as outlined for the scarified soils above. At the high end of the above recommended moisture content range, some pumping of the lean clay overexcavation/backfill materials may be observed and would be expected. Care should be taken to maintain the proper moisture content in the bearing/subgrade soils prior to foundation and floor slab concrete placement and/or paving. The prepared structural mat should not be left exposed for extended periods of time. In the event that the reconditioned soils are allowed to dry out or if rain, snowmelt or water from any source is allowed to infiltrate the bearing/subgrade soils, reworking of those materials or removal/ replacement procedures may be required. Inherent risks exist when building in areas of expansive soils/bedrock. The overexcavation/ backfill procedures outlined above will reduce, but not eliminate, the potential for movement of the building foundation, floor slab and site pavements subsequent to Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 8 construction. The in-place materials below the moisture conditioned zone can increase in moisture content causing movement of the overlying improvements. Some movement of the lightly-loaded building floor slab and site pavements should be expected. If some limited structural and floor slab movement and associated distress cannot be tolerated, drilled pier foundations and structural floor systems should be employed. Dewatering Groundwater was measured in most of the open boreholes at depths ranging from approximately 6 to 8½ feet below ground surface when checked about six (6) days after the completion of drilling. As a result, dewatering parts of the removal excavations as recommended above is not expected, but may be required in limited areas. Based on the materials encountered in the completed site borings, results of laboratory testing and observed depth to groundwater, we expect dewatering of smaller removal excavations could be completed through open pumping procedures from sumps and ditches. Larger removal excavations may require well-point systems to keep up with infiltration water. Dewatering procedures would be expected to be facilitated if construction is completed during periods of seasonal low groundwater levels. It has been our experience that seasonal low groundwater levels typically occur over winter or late summer, several weeks after localized irrigation features stop running water. For open pumping dewatering procedures, care should be taken to construct a suitable sump outside of the improvement area. Fine-grained materials can be drawn to the sump area, creating unsuitable bearing conditions. A sump should consist of a slotted pipe large enough to house a submersible pump, extended deep enough such that when it is pumped out, the entire excavation will be drained. Pumps are typically suspended a minimum of 12 inches above the bottom of the pit in order to provide room for sediment. The slotted pipe should be surrounded by a much larger mass of free-draining gravel. A ¾-inch screened rock could be considered to develop the sedimentation zone. A larger sedimentation zone will reduce water velocities, allowing fines to settle out prior to entering the slotted pipe and mechanical pump. Periodic cleaning and maintenance of the sump should be anticipated. Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 9 Drainage ditches should be constructed outside of the immediate work area to allow for collection of the infiltration waters and feeding of the sump. It may be necessary to construct shallow ditches around the perimeter of the foundation excavations in order to help intercept any infiltration water before it enters and flows laterally across the interior of the excavation to reach the drains. Ditches should be filled with free-draining gravel to reduce the potential for erosion and sloped to provide positive gravity drainage to the sump. For larger water infiltration rates, socked perforated pipe could be installed within the free draining aggregate in the collection ditches in order to facilitate drainage to the sump. Perforated pipe should not be installed beneath foundation concrete or within the zone of foundation influence which can be estimated at a 1:1 slope extending out from the bottom edges of the pads. Careful observation of seepage waters should be completed at the start of pumping. If excessive fines are observed being transported up from the bottom or out of the sides of any excavation, pumping should be stopped and the excavation flooded until methods to reduce soil migration can be employed. Foundations For design of spread footing foundations bearing on a suitable zone of overexcavation/ backfill soils placed and compacted as outlined above, we recommend using a maximum net allowable soil bearing pressure of 1,500 psf. As a precaution, we recommend continuous spread footing and isolated pad foundations be designed to maintain a minimum dead-load pressure of 500 psf (or as high as practical) on the supporting soils. 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 spread 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 Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 10 resistance calculations. A coefficient of friction of 0.35 could be used between foundation and floor slab concrete and the bearing/subgrade soils to resist sliding. The recommended passive equivalent fluid pressure value and coefficient of friction do not include a factor of safety. Backfill placed adjacent to foundation walls should consist of approved LVC soils free from organic matter, debris and other objectionable materials. The on-site lean clay and sand and gravel could be used as foundation wall backfill. Foundation wall backfill soils should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture and compacted as outlined in the “Foundation Bearing and Subgrade Development” section of this report. Excessive lateral stresses can be imposed on foundation walls when using heavier mechanical compaction equipment. We recommend compaction of unbalanced foundation wall backfill soils be completed using light mechanical or hand compaction equipment. We estimate settlement of footing foundations supported on a suitable mat of properly- placed and compacted overexcavation/backfill and resulting from the assumed structural loads would be less than 1 inch. 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 those supported elements could occur. Seismicity Based on the results of this investigation and Soilogic review of the Minimum Design Loads and Associated Criteria for Buildings and Other Structures (ASCE/SEI 7-22), a soil profile type CD 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 = 0.15 and SD1 = 0.051 could be used. Floor Slabs The building floor slab could be supported directly on a suitable zone of overexcavation/ backfill material placed and compacted as outlined above. A modulus of subgrade reaction Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 11 (k) value of 150 pci could be used for design of floor slabs supported on overexcavation/ backfill soils consisting of the on-site clay and/or similar soils. Disturbed subgrades or subgrade materials that have been allowed to dry out or become wet and softened should be removed and replaced or reconditioned in place prior to concrete placement. The floor slab should be designed and constructed as a floating slab, separated from foundation walls, columns and plumbing and mechanical penetrations by the use of block- outs or appropriate isolation material. In addition, we recommend all partition walls supported above isolated 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 structure. A minimum one and one-half (1½) inch void space is recommended beneath all floating walls. Special attention to door and stair framing, drywall installation and trim carpentry should be taken to isolate those elements from the floor slab, allowing for some differential floor slab-to-foundation movement to occur without transmitting stresses to the overlying structure. Depending on the type of floor covering and floor covering adhesive used, a vapor barrier may be required immediately beneath the floor slab in order 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 slab 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. Pavement and Exterior Flatwork Subgrades Pavement subgrades should be developed as outlined in the “Foundation Bearing and Subgrade Development” section of this report. Site pavements could be supported directly on suitable overexcavation/backfill soils placed and compacted as outlined in that section. Care should be taken to avoid disturbing the overexcavation/backfill soils prior to Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 12 placement of site pavements. In addition, efforts to maintain the proper moisture content in the subgrade soils should be made. If subgrade soils are disturbed or allowed to dry out or become elevated in moisture content, those materials should be reworked in place or removed and replaced prior to paving or concrete placement. Some movement of site pavements should be expected as the moisture content of the subgrade soils increases subsequent to construction. Deeper overexcavation/backfill procedures could be considered beneath site pavements to further reduce the potential for post-construction movement of those supported improvements. Care should be taken to ensure that when site pavements move, positive drainage will be maintained away from the structure. Site Pavements Based on the materials encountered in the completed site borings and results of laboratory testing, pavement subgrades are expected to consist of reconditioned lean clay. These soils classify as A-6 soils in accordance with the American Association of State and Highway Transportation Officials (AASHTO) classification system and would be expected to exhibit low remolded shear strength. A resistance value (R-value) of 5 was estimated for the subgrade soils and used in the pavement section design. Traffic loading on the 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 trash and delivery trucks. Equivalent 18-kip single axle loads (ESAL’s) were estimated for the quantity of site traffic anticipated. Two (2) general pavement design categories are outlined below in Table I. 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 heavy truck traffic. Proofrolling of the pavement subgrades should be completed to help identify unstable areas. Areas which pump or deform excessively should be mended prior to aggregate base course and asphaltic concrete placement. Isolated areas of subgrade instability can be mended on a case-by-case basis. If more extensive areas of subgrade instability are Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 13 observed we recommend consideration be given to stabilization of the pavement subgrades with Class C fly ash or Portland cement (pending results of water-soluble sulfate testing). 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 chemical-stabilized subgrade soils are outlined below in Table I. It has been our experience that full-depth asphaltic concrete pavement sections typically do not perform as well as structurally equivalent composite pavement sections in areas of lean clay subgrade soils and we do not recommend full-depth asphalt sections be constructed for this project. Alternative pavement sections could be considered and we would be happy to discuss any alternatives at your request. TABLE 1 – 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) Chemically Stabilized Subgrade 3” 4” 12” 4” 6” 12” Option C – Portland Cement Concrete Pavement 5” 6” 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 or other governing entity. 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 Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 14 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 12% Class ‘C’ fly ash (or 5% Portland cement, pending results of water-soluble sulfate content testing being completed on the subgrade soils) based on component dry unit weights. A 12-inch thick stabilized zone should be constructed by thoroughly blending the fly ash or Portland cement 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 and 30 minutes of cement 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 air entrained and have a minimum 28-day compressive strength of 4,000 or 4,500 psi (pending results of WSS testing). 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. Drainage Positive drainage is imperative for satisfactory long-term performance of the proposed building and associated site improvements. We recommend positive drainage be developed away from the structure during construction and maintained throughout the life of the site improvements, with twelve (12) inches of fall in the first 10 feet away from the building. Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 15 Shallower slopes could be considered in hardscape areas. In the event that poor or negative drainage develops adjacent to the building over time, 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 and pavement subgrade soils. We recommend watering systems be placed a minimum of 5 feet away from the perimeter of the site structure 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 structure, with the gutter downspouts, roof drains or scuppers extended to discharge a minimum of 5 feet away from structural, flatwork and pavement elements. Water which is allowed to pond adjacent to site improvements can result in unsatisfactory performance of those improvements over time. LIMITATIONS 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 provide 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 and supplemental recommendations can be 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 Geotechnical Subsurface Exploration Report Prospect Properties Basketball Facility - Lot 5, Prospect Park East, P.U.D. 1601 Sharp Point Drive, Fort Collins, Colorado Soilogic # 22-1426 16 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 45 4" CFA Automatic JJ / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) 4 - 6" VEGETATION & TOPSOIL - 1 POSSIBLE EXISTING FILL MATERIAL;- CL LEAN CLAY with SAND 2 brown, beige, rust - minor GRAVEL 3 - 4 - 5 CS 42 7.4 -N/A --NL NP 6.5% - 6 - 7 - SP-SM SAND with SILT and GRAVEL 8 brown, rust - medium dense to dense 9 - 10 CS 34 5.0 -N/A ----- - 11 - 12 - 13 - 14 - 15 CS 50/11 6.0 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 US C S Sa m p l e r Atterberg Limits Surface Elev.-Field Personnel:6 Days After Drilling Dci @ 6' Finish Date 12/5/2022 Hammer Type:After Drilling Wci @ 7' Sheet Drilling Rig:Water Depth Information Start Date 12/5/2022 Auger Type:During Drilling 7.0' PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 LOG OF BORING B-2 1/1 CME 45 4" CFA Automatic JJ / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) 4 - 6" VEGETATION & TOPSOIL - 1 2-3' POSSIBLE EXISTING FILL - 2 CL LEAN CLAY with SAND - to SC varies to CLAYEY SAND 3 CS 28 9.6 116.9 9000+2.8%5600 --- brown, beige, rust - stiff to very stiff / loose to medium dense 4 minor GRAVEL - 5 CS 12 19.5 106.7 7500 --34 15 44.4% - 6 - 7 - 8 - 9 - SP-SM SAND with SILT and GRAVEL 10 CS 36 4.7 -N/A ----- brown, rust - medium dense to dense 11 - 12 - 13 - 14 - 15 CS 50 8.0 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 US C S Sa m p l e r Atterberg Limits Start Date 12/5/2022 Auger Type:During Drilling 9.0' Finish Date 12/5/2022 Hammer Type:After Drilling Wci @ 9' Surface Elev.-Field Personnel:6 Days After Drilling 8.0' LOG OF BORING B-3 1/1 CME 45 4" CFA Automatic JJ / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) 4 - 6" VEGETATION & TOPSOIL - 1 2-3' POSSIBLE EXISTING FILL - 2 - CL LEAN CLAY with SAND 3 brown, beige, rust - hard 4 minor GRAVEL - 5 CS 50/11 14.1 105.3 9000+3.2%4500 --- - 6 - 7 - 8 - 9 - SP-SM SAND with SILT and GRAVEL 10 CS 26 4.8 -N/A ----- brown, rust - medium dense to dense 11 - 12 - 13 - 14 - 15 CS 50/8 6.2 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 US C S Sa m p l e r Atterberg Limits Start Date 12/5/2022 Auger Type:During Drilling 9.5' Finish Date 12/5/2022 Hammer Type:After Drilling Wci @ 9.5' Surface Elev.-Field Personnel:6 Days After Drilling Wci @ 8.5' LOG OF BORING B-4 1/1 CME 45 4" CFA Automatic JJ / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) 4 - 6" VEGETATION & TOPSOIL - 1 2-3' POSSIBLE EXISTING FILL - 2 - CL LEAN CLAY with SAND 3 CS 40 9.4 120.3 9000+5.5%10400 --- brown, beige, rust - medium stiff to hard 4 minor GRAVEL - 5 CS 7 15.6 100.3 5000 None <500 --- - 6 - 7 - 8 - 9 - SP-SM SAND with SILT and GRAVEL 10 CS 32 NR NR ------ brown, rust - medium dense to very dense 11 - 12 - 13 - 14 - 15 CS 50/6 7.1 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 US C S Sa m p l e r Atterberg Limits Start Date 12/5/2022 Auger Type:During Drilling 9.0' Finish Date 12/5/2022 Hammer Type:After Drilling Wci @ 9' Surface Elev.-Field Personnel:6 Days After Drilling 6.0' LOG OF BORING B-5 1/1 CME 45 4" CFA Automatic JJ / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) 4 - 6" VEGETATION & TOPSOIL - 1 2-3' POSSIBLE EXISTING FILL - 2 CL LEAN CLAY with SAND - brown, beige, rust 3 CS 34 11.3 120.1 9000+2.4%4700 --- very stiff - minor GRAVEL 4 - 5 CS 20 12.1 115.3 9000+----- - 6 - 7 - 8 - 9 SP-SM SAND with SILT and GRAVEL - brown, rust 10 CS 29 9.0 -N/A ----- medium dense - 11 - 12 - 13 - 14 - 15 CS 34 7.0 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 US C S Sa m p l e r Atterberg Limits Start Date 12/5/2022 Auger Type:During Drilling 9.5' Finish Date 12/5/2022 Hammer Type:After Drilling Wci @ 9.5' Surface Elev.-Field Personnel:6 Days After Drilling Wci @ 8.5' LOG OF BORING B-6 1/1 CME 45 4" CFA Automatic JJ / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) 4 - 6" VEGETATION & TOPSOIL - POSSIBLE EXISTING FILL MATERIAL;1 CL LEAN CLAY with SAND - brown, beige, rust 2 very stiff - minor GRAVEL 3 CS 19 6.8 122.2 9000+----- - 4 - 5 CS 34 7.9 -N/A ----- - 6 - 7 - 8 - SP-SM SAND with SILT and GRAVEL 9 brown, rust - medium dense to dense 10 CS 39 7.0 -N/A --NL NP 4.7% - 11 - 12 - 13 - 14 - 15 CS 50/11 6.0 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 US C S Sa m p l e r Atterberg Limits Start Date 12/5/2022 Auger Type:During Drilling 7.0' Finish Date 12/5/2022 Hammer Type:After Drilling Wci @ 7' Surface Elev.-Field Personnel:6 Days After Drilling Wci @ 6.5' LOG OF BORING B-7 1/1 CME 45 4" CFA Automatic JJ / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) 4 - 6" VEGETATION & TOPSOIL - 1 2-3' POSSIBLE EXISTING FILL - 2 - CL LEAN CLAY with SAND 3 brown, beige, rust - hard 4 minor GRAVEL - 5 CS 50/10 10.4 118.0 9000+1.3%2900 --- - 6 - 7 - 8 - 9 - SP-SM SAND with SILT and GRAVEL 10 CS 28 5.9 -N/A ----- brown, rust - medium dense to dense 11 - 12 - 13 - 14 - 15 CS 50/8 6.3 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 US C S Sa m p l e r Atterberg Limits Start Date 12/5/2022 Auger Type:During Drilling 10.0' Finish Date 12/5/2022 Hammer Type:After Drilling Wci @ 10' Surface Elev.-Field Personnel:6 Days After Drilling Wci @ 8' LOG OF BORING B-8 1/1 CME 45 4" CFA Automatic JJ / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) 4 - 6" VEGETATION & TOPSOIL - 1 2-3' POSSIBLE EXISTING FILL - 2 - 3 CS 28 9.4 118.6 9000+3.2%5500 --- CL LEAN CLAY with SAND - brown, beige, rust 4 very stiff - minor GRAVEL 5 CS 30 10.2 120.7 9000+3.6%6800 --- - 6 - 7 - 8 - 9 - 10 CS 36 6.6 -N/A ----- SP-SM SAND with SILT and GRAVEL - brown, rust 11 medium dense to dense - 12 - 13 - 14 - 15 CS 50/10 7.2 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 US C S Sa m p l e r Atterberg Limits Start Date 12/5/2022 Auger Type:During Drilling 9.0' Finish Date 12/5/2022 Hammer Type:After Drilling Wci @ 9' Surface Elev.-Field Personnel:6 Days After Drilling Wci @ 8.5' LOG OF BORING B-9 1/1 CME 45 4" CFA Automatic JJ / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) 4 - 6" VEGETATION & TOPSOIL - 1 2-3' POSSIBLE EXISTING FILL - 2 - CL LEAN CLAY with SAND 3 CS 31 10.3 122.9 9000+4.8%10600 --- brown, beige, rust - very stiff to hard 4 minor GRAVEL - 5 CS 38 8.8 122.5 9000+4.5%10200 --- - 6 - 7 SP-SM SAND with SILT and GRAVEL - brown, rust 8 medium dense - 9 - 10 CS 36 5.8 -N/A ----- BOTTOM OF BORING @ 10.0'- 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 US C S Sa m p l e r Atterberg Limits Start Date 12/5/2022 Auger Type:During Drilling 10.0' Finish Date 12/5/2022 Hammer Type:After Drilling Wci @ 10' Surface Elev.-Field Personnel:6 Days After Drilling Wci @ 8.5' LOG OF BORING B-10 1/1 CME 45 4" CFA Automatic JJ / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) 4 - 6" VEGETATION & TOPSOIL - 1 2-3' POSSIBLE EXISTING FILL - 2 CL LEAN CLAY with SAND - brown, beige, rust 3 CS 37 7.5 123.4 9000+----- very stiff to hard - minor GRAVEL 4 - 5 CS 50/7 6.3 -N/A ----- - 6 - SP-SM SAND with SILT and GRAVEL 7 brown, rust - medium dense 8 - 9 - 10 CS 31 8.0 -N/A ----- BOTTOM OF BORING @ 10.0'- 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 US C S Sa m p l e r Atterberg Limits Start Date 12/5/2022 Auger Type:During Drilling None Finish Date 12/5/2022 Hammer Type:After Drilling None Surface Elev.-Field Personnel:6 Days After Drilling None Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf)116.9 500 Final Moisture 13.6% % Swell @ 500 psf 2.8% Swell Pressure (psf)5,600 Sample ID: B-2 @ 2 Initial Moisture 9.6% Sample Description: Possible Existing Fill; Brown Sandy Lean Clay (CL), minor Gravel SWELL/CONSOLIDATION TEST SUMMARY PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 -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 (pcf)105.3 SWELL/CONSOLIDATION TEST SUMMARY PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 Initial Moisture 14.1% Sample ID: B-3 @ 4 Sample Description: Dark Brown/Brown Sandy Lean Clay (CL) with Gravel 500 Final Moisture 21.9% % Swell @ 500 psf 3.2% Swell Pressure (psf)4,500 -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 (pcf)120.3 SWELL/CONSOLIDATION TEST SUMMARY PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 Initial Moisture 9.4% Sample ID: B-4 @ 2 Sample Description: Possible Existing Fill; Brown Sandy Lean Clay (CL), minor Gravel 500 Final Moisture 13.7% % Swell @ 500 psf 5.5% Swell Pressure (psf)10,400 -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 (pcf)100.3 SWELL/CONSOLIDATION TEST SUMMARY PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 Initial Moisture 15.6% Sample ID: B-4 @ 4 Sample Description: Brown/Rust Lean Clay with Sand (CL), minor Gravel 500 Final Moisture 19.6% % Swell @ 500 psf None Swell Pressure (psf)<500 -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 (pcf)120.1 SWELL/CONSOLIDATION TEST SUMMARY PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 Initial Moisture 11.3% Sample ID: B-5 @ 2 Sample Description: Possible Existing Fill; Brown/Rust Sandy Lean Clay (CL), minor Gravel 500 Final Moisture 14.4% % Swell @ 500 psf 2.4% Swell Pressure (psf)4,700 -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 (pcf)118.0 SWELL/CONSOLIDATION TEST SUMMARY PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 Initial Moisture 10.4% Sample ID: B-7 @ 4 Sample Description: Brown/Beige Lean Clay with Sand (CL), minor Gravel 500 Final Moisture 13.3% % Swell @ 500 psf 1.3% Swell Pressure (psf)2,900 -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 (pcf)118.6 SWELL/CONSOLIDATION TEST SUMMARY PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 Initial Moisture 9.4% Sample ID: B-8 @ 2 Sample Description: Possible Existing Fill; Brown/Beige Sandy Lean Clay (CL), minor Gravel 500 Final Moisture 14.6% % Swell @ 500 psf 3.2% Swell Pressure (psf)5,500 -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 (pcf)120.7 SWELL/CONSOLIDATION TEST SUMMARY PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 Initial Moisture 10.2% Sample ID: B-8 @ 4 Sample Description: Brown Sandy Lean Clay (CL), trace Gravel 500 Final Moisture 13.9% % Swell @ 500 psf 3.6% Swell Pressure (psf)6,800 -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 (pcf)122.9 SWELL/CONSOLIDATION TEST SUMMARY PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 Initial Moisture 10.3% Sample ID: B-9 @ 2 Sample Description: Possible Existing Fill; Dark Brown/Brown Sandy Lean Clay (CL), minor Gravel 500 Final Moisture 13.2% % Swell @ 500 psf 4.8% Swell Pressure (psf)10,600 -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 (pcf)122.5 SWELL/CONSOLIDATION TEST SUMMARY PROPOSED BASKETBALL GYM - LOT 5, PROSPECT PARK EAST, P.U.D. 1601 SHARP POINT DRIVE, FORT COLLINS, COLORADO Project # 22-1426 December 2022 Initial Moisture 8.8% Sample ID: B-9 @ 4 Sample Description: Brown Lean Clay with Sand (CL), trace Gravel 500 Final Moisture 12.8% % Swell @ 500 psf 4.5% Swell Pressure (psf)10,200 -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Soil Classification Group Symbol Group NameB Cu ! 4 and 1 " Cc " 3E GW Well graded gravelF Clean Gravels 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 Cu ! 6 and 1 " Cc " 3E SW Well graded sandI Clean Sands 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 PI > 7 and plots on or above “A” lineJ CL Lean clayK,L,M Silts and Clays 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 Liquid limit - oven dried Organic clayK,L,M,P Organic 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 = 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. 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+