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Home My WebLink AboutPALMOS INDUSTRIAL - PDP220012 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGEOTECHNICAL SUBSURFACE EXPLORATION REPORT PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO SOILOGIC # 21-1311 October 12, 2021 Soilogic, Inc. 3522 Draft Horse Court • Loveland, CO 80538 • (970) 535-6144 October 12, 2021 Palmos Development Corporation 2775 Iris Avenue Boulder, Colorado 80304 Attn: Mr. Terry Palmos Re: Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street Fort Collins, Colorado Soilogic Project # 21-1311 Mr. Palmos: Soilogic, Inc. (Soilogic) personnel have completed the geotechnical subsurface exploration you requested for the proposed light industrial/warehouse buildings to be constructed at 115 Hickory Street in Fort Collins, Colorado. The results of our subsurface exploration and pertinent geotechnical engineering recommendations are included with this report. The subsurface materials encountered in the completed site borings consisted of apparently-natural reddish-brown/gray/rust sandy lean clay at the surface at the boring locations. The lean clay varied from medium stiff to stiff in terms of consistency, exhibited variable swell potential near-surface (ranging from low to high) and no swell potential with depth at current moisture and density conditions and extended to the maximum depth explored at the location of boring B-6 at a depth of about 5 feet below present site grade. At the locations of borings B-1 through B-5 and B-7, the lean clay extended to depths ranging from 3½ to 5 feet below present site grade, where it was underlain by brown/rust sand with varying amounts of clay, silt and gravel. The sand varied from loose to very dense in terms of relative density, exhibited low swell potential at in-situ moisture and density conditions and extended to the maximum depths explored in these borings at depths ranging from about 5 to 15 feet below present site grade. Groundwater was measured in borings B-1 through B-5 at depths ranging from about 8 to 9 feet below ground surface when checked immediately after completion of drilling, while borings B-6 and B-7 were dry to the depth explored (approximately 5 feet below ground Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 2 surface) at that time. When checked about eight (8) days after drilling, groundwater levels remained unchanged in borings B-1 through B-4 and borings B-6 and B-7 remained dry to the depth explored. A dry cave-in was measured in boring B-5 at a depth of about 7 feet below ground surface at that time. Based on the subsurface conditions encountered, results of laboratory testing and proposed construction, it is Soilogic’s opinion the proposed light industrial/warehouse buildings could be designed and constructed using conventional spread footing foundations bearing on natural, undisturbed lean clay and/or sand. Care will be needed at the time of construction to ensure all footing foundations bear on natural, undisturbed lean clay and/or sand with suitable strength and low volume change (LVC) potential. Although the deeper- lying lean clay soils encountered in the test borings drilled for this exploration exhibited no to low swell potential at current moisture and density conditions, several samples obtained from the borings at a depth of about two (2) feet below ground surface exhibited moderate to high swell potential. If/where expansive lean clay is identified underlying footing foundations at the time of excavation, extending footing foundations to bear on natural, undisturbed lean clay and/or sand with low swell potential at slightly greater depth, or performing overexcavation/backfill procedures extended to low swelling lean clay and/or sand to redevelop LVC-potential foundation bearing would be required. Overexcavation/backfill procedures extended to natural, undisturbed lean clay with low swell potential and/or sand should also be completed below the building floor slabs. Similar methods should be used to a lesser degree in order to develop LVC-potential pavement subgrades. The overexcavation/backfill procedures would help develop LVC-potential foundation, floor slab and pavement support across the building footprints and pavement areas and reduce the potential for total and differential movement of those supported elements subsequent to construction. Based on the results of completed laboratory testing, the natural site lean clay and sand soils appear suitable for use as LVC fill and overexcavation/backfill to develop the site. Other opinions and recommendations concerning design criteria and construction details for the proposed site improvements are included with this report. Pavement section design options are also included. Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 3 10/12/2021 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: Alec Kaljian, P.E. Darrel DiCarlo, P.E. Project Engineer Senior Project Engineer 10/12/2021 GEOTECHNICAL SUBSURFACE EXPLORATION REPORT PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO SOILOGIC # 21-1311 October 12, 2021 INTRODUCTION This report contains the results of the completed geotechnical subsurface exploration for the proposed light industrial/warehouse buildings to be constructed at 115 Hickory Street 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 building foundations and support of floor slabs and site pavements. Pavement section design recommendations for the site pavements are also included. 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 We understand the project includes the construction of four (4) light industrial/warehouse buildings with plan areas ranging from about 2,500 to 13,293 square feet. We anticipate the proposed new light industrial/warehouse buildings will be lightly-loaded single-story (with possible mezzanines) pre-engineered metal structures constructed as slab-on-grade. Foundations loads for the buildings are anticipated to be relatively light, with maximum continuous wall loads on the order of 3 to 4 kips per lineal foot and individual column loads less than 150 kips. Site drive and parking area pavements are also anticipated as part of the proposed site improvements. Traffic loading on site pavements is expected to consist of low volumes of light passenger vehicles with light to moderate volumes of trash and delivery truck traffic. Small grade changes (on the order of 2 feet or less) are anticipated to develop finish site grades in the building and pavement areas. SITE DESCRIPTION The development parcel includes approximately an approximate 3.8-acre parcel of land within the Riverside Park development, located at 115 Hickory Street in Fort Collins, Colorado. At the time of our exploration, the site was sparsely vegetated with native weeds Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 2 and grasses and was relatively level, with the maximum difference in ground surface elevation across the site estimated to be on the order of 2 to 4 feet. Chain link fences were noted on the eastern portion of the property, while a stockpile of railroad rails and ties were noted on the western portion of the property. Several medium-size diameter deciduous trees and bushes were noted on the eastern portion of the property. Evidence of prior building construction was not observed on the development lot by Soilogic personnel at the time of our site exploration. SITE EXPLORATION Field Exploration To develop subsurface information for the proposed site improvements, a total of seven (7) soil borings were completed. Five (5) borings were advanced in the areas of the proposed light industrial/warehouse buildings to a depth of approximately 15 feet below present site grade. Two (2) additional borings were completed in the site pavement areas to a depth of approximately 5 feet below ground surface. The boring locations were established in the field by Soilogic, Inc. (Soilogic) personnel based on a provided site plan, using a mechanical surveyor's wheel and estimating angles from identifiable site references. A diagram indicating the approximate boring locations is included with this report. The boring locations 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 barrel sampling procedures in general accordance with ASTM specification D-1586. As part of the D-1586 sampling procedure, the 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 or relative density of the 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 Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 3 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 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. 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 materials (clay and silt) in a sample. Swell/consolidation tests are performed to evaluate soil 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 and/or discussed subsequently in this report. Water Soluble Sulfate (WSS) tests are currently being completed on two (2) selected soil samples to evaluate corrosive soil characteristics with respect to buried concrete. Results will be provided when they become available. SUBSURFACE CONDITIONS The subsurface materials encountered in the completed site borings consisted of apparently-natural reddish-brown/gray/rust sandy lean clay at the surface at the boring locations. The lean clay varied from medium stiff to stiff in terms of consistency, exhibited variable swell potential near-surface (ranging from low to high) and no swell potential with depth at current moisture and density conditions and extended to the maximum depths explored at the location of boring B-6 at a depth of about 5 feet below present site grade. At the locations of borings B-1 through B-5 and B-7, the lean clay extended to depths ranging from 3½ to 5 feet below present site grade, where it was underlain by brown/rust Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 4 sand with varying amounts of clay, silt and gravel. The sand varied from loose to very dense in terms of relative density, exhibited low swell potential at in-situ moisture and density conditions and extended to the maximum depths explored in these borings at depths ranging from about 5 to 15 feet below present site grade. The stratigraphy indicated 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 measured in borings B-1 through B-5 at depths ranging from about 8 to 9 feet below ground surface when checked immediately after completion of drilling, while borings B-6 and B-7 were dry to the depth explored (approximately 5 feet below ground surface) at that time. When checked about eight (8) days after drilling, groundwater levels remained unchanged in borings B-1 through B-4 and borings B-6 and B-7 remained dry to the depth explored. A dry cave-in was measured in boring B-5 at a depth of about 7 feet below ground surface at that time. Groundwater level information is indicated in the upper right-hand corner of the attached boring logs. Groundwater levels will vary due to seasonal variations in precipitation, 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 General 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 and low volume change potential. Near-surface lean clay exhibiting borderline moderate/high swell potential was identified in several of the completed site borings extending to depths approaching 2 to 3 feet below present site grade. Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 5 As a precaution, and in order to develop consistent foundation bearing, we recommend all shallow stemwall footing foundations be extended through expansive near-surface clays (if/where present) to bear on natural, undisturbed moist lean clay and/or sand with low swell potential. Overexcavation/backfill procedures extended to natural, undisturbed lean clay and/or sand with low swell potential could also be considered in these areas. Overexcavation/backfill procedures extended to low swelling clay and/or sand below the building floor slabs are recommended to redevelop low volume-change (LVC) support for these improvements. Similar overexcavation/backfill procedures below site pavements are also recommended to a lesser degree prior to concrete/asphalt placement/surfacing. Site Development All existing topsoil and vegetation should be completely removed from the building, and pavement areas. Expansive near-surface lean clay subgrade soils identified within the proposed building areas should also be completely removed to natural, undisturbed lean clay and/or sand with low swell potential at this time. In addition, all trees, tree root systems and dry and desiccated soils associated with the tree root systems should be completely removed from within the proposed residence and fill areas. After stripping and completing all cuts and removal procedures and prior to placement of any new fill, removal area backfill or site pavements, we recommend the exposed subgrades be scarified to a depth of 9 inches, adjusted to within ±2% of optimum moisture content and uniformly re-compacted to at least 95% of the maximum standard Proctor density (ASTM D698). Since movement of 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 level, with the understanding that some movement of site pavements will occur subsequent to construction. The 24-inch LVC zone beneath site pavements could be developed through any combination of overexcavation/backfill, subgrade reconditioning and new fill placement procedures. Fill and overexcavation/backfill soils required to develop the site should consist of approved LVC soils free from organic matter, debris and other objectionable materials. Based on results of the completed laboratory testing, it is our opinion site lean clay and Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 6 sand could be used as fill and/or overexcavation/backfill to develop the site provided the proper moisture content is developed in the materials at the time of placement and compaction. If it is necessary to import additional material to the site for use as fill, those materials should consist of approved relatively impervious LVC materials. We recommend suitable fill materials be uniformly placed and compacted in loose lifts not to exceed 9 inches thick, moisture conditioned and compacted as recommended for the scarified subgrade soils above. Care should be taken to avoid disturbing the reconditioned subgrade soils and placed fill materials prior to placement of any overlying improvements. Soils which are allowed to dry or 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 and/or paving. Foundations Based on the materials encountered in the completed site borings and results of field and laboratory testing, it is our opinion the proposed buildings could be supported by continuous spread footing and isolated pad foundations bearing on natural, undisturbed, lean clay and/or sand with low swell potential and/or properly placed and compacted overexcavation/backfill (if/where required) developed as outlined above. For design of foundations bearing on natural, undisturbed, medium stiff to stiff lean clay and/or loose to very dense sand with low swell potential and/or overexcavation/backfill soils compacted to at least 95% of the material’s standard Proctor maximum dry density (if/where completed), we recommend using a maximum net allowable soil bearing pressure of 1,500 psf. As a precaution, we recommend the footing foundations be sized to maintain a minimum dead-load pressure of 500 psf (or as high as practical) on the bearing soils. Exterior footings shall 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. Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 7 Backfill placed adjacent to foundation walls should consist of LVC potential and relatively impervious soils free from organic matter, debris and other objectionable materials. The site lean clay and sand could be used as backfill in this area provided the proper moisture content is developed in those materials at the time of placement and compaction. We recommend the site lean clay, sand or similar backfill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture and compacted as previously outlined in the “Site Development” section of this report. 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. We estimate settlement of footing foundations designed and constructed as outlined above and resulting from the assumed structural loads would be less than 1 inch. Differential settlement could approach the amount of total movement estimated above. If water from any source is allowed to infiltrate the foundation bearing soils, additional movement of the foundations could occur. Seismic Design Based on the results of this investigation and Soilogic review of the Minimum Design Loads for Buildings and Other Structures (ASCE 7-16), 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 = 0.209 and SD1 = 0.09 could be used. At-Grade Floor Slabs and Site Pavements In slab-on-grade and site pavement areas, those slabs/pavements could be supported directly on reconditioned natural site soils with low swell potential, or properly placed and compacted fill and/or overexcavation/backfill developed as outlined in the “Site Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 8 Development” section of this report. A modulus of subgrade reaction (k) value of 150 pci could be used for design of at-grade floor slabs supported on reconditioned natural site soils or properly placed and compacted fill and/or overexcavation/backfill. Disturbed subgrades or subgrade soils that have been allowed to dry out or become wet and softened should be removed and replaced or reconditioned in place prior to floor slab construction. Floor slabs should be designed and constructed as floating slabs, separated from foundation walls, columns and plumbing and mechanical penetrations by the use of block-outs or appropriate isolation material. Additionally, 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 structures. 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 structures. Depending on the type of floor covering and floor covering adhesive used in finished slab- on-ground areas, a vapor barrier may be required immediately beneath the floor slab 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. Subgrade soils expected to receive floor slabs and pavements 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, reworking of those materials or removal/ replacement procedures may be required. Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 9 Some movement of site pavements should be expected as the moisture content of the subgrade soils increases subsequent to construction. Based on results of the completed field and laboratory testing, we expect the amount of movement of pavements supported on properly placed and compacted fill and/or overexcavation/backfill would be limited. Care should be taken to ensure that when site pavements move, positive drainage will be maintained away from the structure. Pavements 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 low volumes of light vehicle traffic and occasional heavier 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 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 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 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 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. Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 10 TABLE I – 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) Chemical Stabilized Subgrade 3” 4” 12” 4” 6” 12” Option C - Portland Cement Concrete Pavement PCCP 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 Larimer County Urban Area Street Standards (LCUASS) or other local 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 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 based on component dry unit weights. A 12-inch- thick stabilized zone should be constructed by thoroughly blending the fly ash or 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 or 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 entrained with 4% to 8% air and have a Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 11 minimum 28-day compressive strength of 4,000 psi. 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 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 twelve (12) inches of fall in the first 10 feet away from the buildings. Shallower slopes could be considered in hardscape areas. In the event that poor or negative drainage develops adjacent to the buildings 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 perimeters 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 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. Geotechnical Subsurface Exploration Report Proposed Light Industrial/Warehouse Development (Part of Riverside Park) 115 Hickory Street, Fort Collins, Colorado Soilogic Project # 21-1311 12 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 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 HM / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) - 1 CL SANDY LEAN CLAY - reddish-brown, gray, rust 2 stiff - 3 CS 14 9.5 105.1 9000+1.9%1600 --- - 4 - 5 CS 10 11.0 119.6 9000+0.3%800 --- - 6 - 7 - SP-SC/SAND with varying amounts 8 SP-SM of CLAY, SILT and GRAVEL - brown, rust 9 loose to very dense - 10 CS 37 5.7 -N/A ----- - 11 - 12 - 13 - 14 - 15 SS 50/10 5.5 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 Sheet Drilling Rig:Water Depth Information Start Date 9/23/2021 Auger Type:During Drilling 8.0' Finish Date 9/23/2021 Hammer Type:After Drilling 8.0'USCSSamplerAtterberg Limits Surface Elev.-Field Personnel:8 Days After Drilling 8.0' LOG OF BORING B-2 1/1 CME 45 4" CFA Automatic HM / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) - 1 - CL SANDY LEAN CLAY 2 reddish-brown, gray, rust - medium stiff 3 - 4 - 5 CS 9 18.5 102.6 9000+None <500 --- - 6 - 7 - 8 - SP-SC/SAND with varying amounts 9 SP-SM of CLAY, SILT and GRAVEL - brown, rust 10 CS 19 8.2 116.8 N/A ----- medium dense to very dense - 11 - 12 - 13 - 14 - 15 SS 50/9 9.7 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 Finish Date 9/23/2021 Hammer Type:After Drilling 9.0' Start Date 9/23/2021 Auger Type:During Drilling 9.0' 8 Days After Drilling 9.0'USCSSamplerAtterberg Limits Surface Elev.-Field Personnel: LOG OF BORING B-3 1/1 CME 45 4" CFA Automatic HM / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) - 1 - CL SANDY LEAN CLAY 2 reddish-brown, gray, rust - medium stiff 3 CS 9 24.0 99.0 7500 0.3%800 --- - 4 - 5 CS 8 18.3 110.6 5000 --27 13 67.2% - 6 - 7 - 8 - SP-SC/SAND with varying amounts 9 SP-SM of CLAY, SILT and GRAVEL - brown, rust 10 SS 50/11 12.3 -N/A ----- very dense - 11 - 12 - 13 - 14 - 15 SS 50/7 5.5 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 Finish Date 9/23/2021 Hammer Type:After Drilling 8.5' Start Date 9/23/2021 Auger Type:During Drilling 8.5' 8 Days After Drilling 8.5'USCSSamplerAtterberg Limits Surface Elev.-Field Personnel: LOG OF BORING B-4 1/1 CME 45 4" CFA Automatic HM / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) - 1 CL SANDY LEAN CLAY - reddish-brown, gray, rust 2 - 3 - 4 - 5 CS 21 10.7 -N/A ----- - 6 - 7 - SP-SC/SAND with varying amounts 8 SP-SM of CLAY, SILT and GRAVEL - brown, rust 9 medium dense to dense - 10 CS 26 33.7 95.5 N/A ----- - 11 - 12 - 13 - 14 - 15 CS 50/10 10.4 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 Finish Date 9/23/2021 Hammer Type:After Drilling 8.0' Start Date 9/23/2021 Auger Type:During Drilling 8.0' 8 Days After Drilling 8.0'USCSSamplerAtterberg Limits Surface Elev.-Field Personnel: LOG OF BORING B-5 1/1 CME 45 4" CFA Automatic HM / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) - 1 CL SANDY LEAN CLAY - reddish-brown, gray, rust 2 stiff - 3 CS 18 6.8 117.8 9000+7.1%16000 --- - 4 - 5 CS 50/8 0.5 -N/A ----7.3% - 6 - 7 - 8 SP-SC/SAND with varying amounts - SP-SM of CLAY, SILT and GRAVEL 9 brown, rust - medium dense to very dense 10 CS 19 7.2 122.5 N/A ----- - 11 - 12 - 13 - 14 - 15 SS 50/9 12.8 -N/A ----- BOTTOM OF BORING @ 15.0'- 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 Finish Date 9/23/2021 Hammer Type:After Drilling 9.5' Start Date 9/23/2021 Auger Type:During Drilling 9.5' 8 Days After Drilling Dci @ 7.0'USCSSamplerAtterberg Limits Surface Elev.-Field Personnel: LOG OF BORING B-6 1/1 CME 45 4" CFA Automatic HM / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) - 1 - 2 CL SANDY LEAN CLAY - reddish-brown, gray, rust 3 CS 15 11.3 107.1 9000+3.7%2800 --- medium stiff to stiff - 4 - 5 CS 10 19.1 107.7 8000 None <500 --- BOTTOM OF BORING @ 5.0'- 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 Finish Date 9/23/2021 Hammer Type:After Drilling None Start Date 9/23/2021 Auger Type:During Drilling None 8 Days After Drilling None USCSSamplerAtterberg Limits Surface Elev.-Field Personnel: LOG OF BORING B-7 1/1 CME 45 4" CFA Automatic HM / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N"MC DD qu % Swell @ Pressure # 200 Sieve (ft)(%)(pcf)(psf)500 psf (psf)LL PI (%) - 1 CL SANDY LEAN CLAY - reddish-brown, gray, rust 2 stiff - 3 CS 18 5.1 ------- - 4 SC CLAYEY SAND with GRAVEL - brown, rust / loose 5 CS 10 17.0 103.6 8500 ----- BOTTOM OF BORING @ 5.0'- 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig:Water Depth Information PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 Finish Date 9/23/2021 Hammer Type:After Drilling None Start Date 9/23/2021 Auger Type:During Drilling None 8 Days After Drilling None USCSSamplerAtterberg Limits Surface Elev.-Field Personnel: Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf)105.1 500 Final Moisture 24.8% % Swell @ 500 psf 1.9% Swell Pressure (psf)1,600 Sample ID: B-1 @ 2 Initial Moisture 9.5% Sample Description: Reddish-Brown/Gray/Rust Sandy Lean Clay (CL) SWELL/CONSOLIDATION TEST SUMMARY PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 -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)119.6 500 Final Moisture 19.3% % Swell @ 500 psf 0.3% Swell Pressure (psf)800 Initial Moisture 11.0% Sample ID: B-1 @ 4 Sample Description: Brown/Rust Clayey Sand (SC) SWELL/CONSOLIDATION TEST SUMMARY PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 -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)102.6 500 Final Moisture 21.5% % Swell @ 500 psf None Swell Pressure (psf)<500 Initial Moisture 18.5% Sample ID: B-2 @ 4 Sample Description: Reddish-Brown/Gray/Rust Sandy Lean Clay (CL) (Swell Only) SWELL/CONSOLIDATION TEST SUMMARY PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 -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)99.0 500 Final Moisture 24.2% % Swell @ 500 psf 0.3% Swell Pressure (psf)800 Initial Moisture 24.0% Sample ID: B-3 @ 2 Sample Description: Reddish-Brown/Gray/Rust Sandy Lean Clay (CL) SWELL/CONSOLIDATION TEST SUMMARY PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 -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)117.8 500 Final Moisture 24.2% % Swell @ 500 psf 7.1% Swell Pressure (psf)16,000 Initial Moisture 6.8% Sample ID: B-5 @ 2 Sample Description: Reddish-Brown/Gray/Rust Sandy Lean Clay (CL) SWELL/CONSOLIDATION TEST SUMMARY PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 -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)107.1 500 Final Moisture 22.0% % Swell @ 500 psf 3.7% Swell Pressure (psf)2,800 Initial Moisture 11.3% Sample ID: B-6 @ 2 Sample Description: Reddish-Brown/Gray/Rust Sandy Lean Clay (CL) SWELL/CONSOLIDATION TEST SUMMARY PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 -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)107.7 500 Final Moisture 19.7% % Swell @ 500 psf None Swell Pressure (psf)<500 Initial Moisture 19.1% Sample ID: B-6 @ 4 Sample Description: Reddish-Brown/Gray/Rust Sandy Lean Clay (CL) SWELL/CONSOLIDATION TEST SUMMARY PROPOSED LIGHT INDUSTRIAL/WAREHOUSE DEVELOPMENT 115 HICKORY STREET, FORT COLLINS, COLORADO Project # 21-1311 October 2021 -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+