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HomeMy WebLinkAboutCOUNTRY CLUB CORNERS SIXTH FILING (CARWASH) - FDP - FDP170012 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGEOTECHNICAL SUBSURFACE EXPLORATION REPORT FIREHOUSE XPRESS CAR WASH #2 LOT 1 – COUNTRY CLUB CORNERS 5TH FILING FORT COLLINS, COLORADO SOILOGIC # 16-1328 January 17, 2017 Soilogic, Inc. 3050 67th Avenue, Suite 200  Greeley, CO 80634  (970) 535-6144 P.O. Box 1121  Hayden, CO 81639  (970) 276-2087 January 17, 2017 C-Three, LLC 3500 South Timberline Road Fort Collins, Colorado 80524 Attn: Mr. Jim Houck Re: Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5 th Filing Fort Collins, Colorado Soilogic # 16-1328 Mr. Houck: Soilogic, Inc. (Soilogic) personnel have completed the geotechnical subsurface exploration you requested for the proposed Firehouse Xpress Car Wash #2 to be constructed on Lot 1 of the Country Club Corners 5 th Filing commercial/retail development in Fort Collins, Colorado. The results of our subsurface exploration and pertinent geotechnical engineering recommendations are included with this report. In general, the subsurface materials encountered in the completed site borings consisted of a thin mantle of vegetation and topsoil underlain by rust/brown/grey lean clay with sand. The lean clay varied from stiff to very stiff in terms of consistency, exhibited low to high swell potential at in-situ moisture and density conditions and extended to depths ranging from approximately 1 to 7½ feet below ground surface, where it transitioned to rust/brown sand 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 material’s physical properties and engineering characteristics and extended to the bottom of all borings at depths ranging from approximately 10 to 15 feet below present site grade. Groundwater was encountered in the completed site borings at depths ranging from approximately 7 to 8½ feet below ground surface when checked immediately after the completion of drilling. When checked approximately 24 hours after completion of drilling, groundwater was measured in borings B-2 through B-5 at depths of approximately 7, 6½, 7½ and 8 feet below ground surface respectively. A Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 2 dry cave-in was measured in boring B-1 and B-3 at a depth of approximately 7 feet below grade 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 car wash building could be constructed with conventional spread footing foundations extended to bear on natural, undisturbed, non-expansive sand and gravel. Extending footing foundations and stepped foundation excavations and foundation walls should be expected in this regard. The building floor slab, exterior flatwork and site pavements should bear on a mat of properly moisture-conditioned and compacted overexcavation/backfill. The overexcavation/backfill procedures will help develop low volume-change (LVC) potential floor slab, exterior flatwork 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. Pavement section design options are also included. 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: Wolf von Carlowitz, P.E. Darrel DiCarlo, P.E. Principal Engineer Senior Project Engineer 36746 44271 GEOTECHNICAL SUBSURFACE EXPLORATION REPORT FIREHOUSE XPRESS CAR WASH #2 LOT 1 – COUNTRY CLUB CORNERS 5TH FILING FORT COLLINS, COLORADO SOILOGIC # 16-1328 January 17, 2017 INTRODUCTION This report contains the results of the completed geotechnical subsurface exploration for the proposed Firehouse Xpress Car Wash #2 to be constructed on Lot 1 of the Country Club Corners 5 th Filing commercial/retail development 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 car wash building foundations and support of floor slabs, exterior flatwork 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 have a plan area of approximately 4,200 square feet and be a single-story masonry structure constructed as slab-on-grade. Foundations loads for the structure are expected to be light, with continuous wall loads less than 3.5 kips per lineal foot and individual column loads less than 75 kips. Paved drive lane and parking areas are anticipated adjacent to the building as part of the proposed site improvements. Small grade changes are anticipated to develop finish site grades in the building and pavement areas. SITE DESCRIPTION The development property includes Lot 1 of the Country Club Corners 5 th Filing industrial development, located at 126 Bristlecone Drive in Fort Collins, Colorado. At the time of our site exploration, the lot was undeveloped and contained a moderate growth of grass vegetation. The building area contained a gentle overall slope downward to the east, with a maximum difference in ground surface elevation across this area estimated to be approximately three (3) feet, while the drive lane and parking areas Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 2 contained a gentle overall slope downward to the south and a maximum difference in ground surface elevation in this area estimated to be approximately two (2) feet. Evidence of prior building construction was not observed in the proposed construction areas at the time of our exploration, however, we understand an existing storm drain crosses the building and pavement areas from north to south and will be relocated as part of the proposed site development. SITE EXPLORATION Field Exploration To develop subsurface information for the proposed site improvements, a total of five (5) soil borings were completed. Two (2) borings were advanced in the area of the proposed car wash building to a depth of approximately 15 feet below present site grade. Three (3) additional borings were completed in the site pavement areas to a depth of approximately 10 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. The boring locations should be considered accurate only to the degree implied by the methods used to make the field measurements. A diagram indicating the approximate boring locations is included with this report. Graphic logs of each of the auger borings are also included. 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 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. Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 3 Laboratory Testing The samples collected were tested in the laboratory to measure natural moisture content and 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 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. Water Soluble Sulfates (WSS) tests were also completed on two (2) selected soil samples to evaluate corrosive soil characteristics with respect to buried concrete and results discussed subsequently in this report. SUBSURFACE CONDITIONS In general, the subsurface materials encountered in the completed site borings consisted of a thin mantle of vegetation and topsoil underlain by rust/brown/grey lean clay with varying amounts of silt and sand. The lean clay varied from stiff to very stiff in terms of consistency, exhibited low to high swell potential at in-situ moisture and density conditions and extended to depths ranging from approximately 1 to 7½ feet below ground surface, where it was underlain by rust/brown sand 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 material’s physical properties and engineering characteristics and extended to the bottom of all borings at depths ranging from approximately 10 to 15 feet below present site grade. Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 4 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 encountered in the completed site borings at depths ranging from approximately 7 to 8½ feet below ground surface when checked immediately after the completion of drilling. When checked approximately 24 hours after completion of drilling, groundwater was measured in borings B-2 through B-5 at depths of approximately 7, 6½, 7½ and 8 feet below ground surface respectively. A dry cave-in was measured in boring B-1 at a depth of approximately 7 feet below grade at that time. Groundwater level information is indicated in the upper right-hand corner of the attached boring logs. Groundwater levels will vary seasonally and over time based on weather conditions, site development, irrigation practices and other hydrologic conditions. Perched and/or trapped groundwater conditions may also be encountered at times throughout the year. Perched water is commonly encountered in soils overlying less permeable soil layers and/or bedrock. Trapped water is typically encountered within more permeable zones of layered soil and bedrock systems. The location and amount of perched/trapped water can also vary over time. ANALYSIS AND RECOMMENDATIONS General The near-surface lean clay soils encountered at this site exhibited low to high swell potential at in-situ moisture and density conditions. Total and differential heaving of site improvements placed directly on or immediately above the expansive clay soils 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 and results of laboratory testing and in order to develop consistent low-volume change potential foundation bearing, we recommend extending footing foundations through the expansive Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 5 near-surface clay to bear on non-expansive sand and gravel, anticipated to be encountered at depths ranging from approximately 1 to 4½ feet below grade. Stepped foundation construction should be expected in this regard. The depth to suitable foundation bearing can best be established at the time of construction through openhole and/or test pit observation. Overexcavation/backfill procedures could also be considered to develop suitable foundation bearing, but would require a consistent thickness of overexcavation/backfill to be developed beneath all footing foundations in order to reduce the potential for excessive differential settlement of the structure subsequent to construction. Overexcavation to low swelling sand and gravel at a depth of approximately 4½ feet below grade at the location of boring B-1 across the entire building footprint could be used for preliminary estimates. Overexcavation/backfill procedures are recommended beneath the building floor slab, exterior flatwork and site pavements to reduce the potential for movement of those supported element subsequent to construction. The risk of some movement cannot be eliminated. Recommendations concerning overexcavation/backfill procedures to redevelop low volume-change (LVC) floor slab, exterior flatwork and pavement support are outlined below. Use of drilled pier foundations and structural floor systems could be considered and would offer a very effective system for mitigating the potential for total and differential movement of the building and building floor slab subsequent to construction in the expansive soils environment. Drilled piers would anchor the building into site bedrock, significantly reducing the potential for movement of the structure. If drilled pier foundations are to be used, structural flooring systems or overexcavation/backfill procedures to develop low volume change (LVC) floor slab subgrades would be required. Deeper subsurface exploration would be required to develop soil and bedrock parameters for use in drilled pier design. Floor Slab and Pavement/Exterior Flatwork Subgrade Development To develop LVC potential floor slab, exterior flatwork and pavement support, and reduce the potential for total and differential movement of the building floor slab, exterior Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 6 flatwork and site pavements 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 floor slab, exterior flatwork and site pavements which will have low potential for volume change subsequent to construction. The LVC mat and surcharge loads placed on the underlying soils 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 beneath the building floor slab should extend to low-swelling sand and gravel, anticipated to be encountered at depths ranging from approximately 1 to 4½ feet below present site grade at the location of borings B-2 and B-1 respectively. Since movement of site pavements and exterior flatwork is generally considered less consequential than structural and floor slab movement, it is our opinion the overexcavation zone beneath site pavements and exterior flatwork could be reduced to a minimum of three (3) feet below finish subgrade level. The 3-foot thick zone can be developed through any combination of overexcavation/backfill and new fill placement procedures. The overexcavation area should extend a minimum of 8 inches laterally past the exterior perimeter of the exterior flatwork and pavement areas for every 12 inches of overexcavation depth. Soils used as fill and overexcavation/backfill should consist of approved materials free from organic matter, debris and other objectionable materials. Based on results of the completed laboratory testing, it is our opinion the site lean clay could be used as overexcavation/backfill provided care is taken to develop the proper moisture content in those materials at the time of placement and compaction. Essentially-granular imported structural fill materials could also be used as overexcavation/backfill in the building area where complete removal of the expansive near surface lean clay will be completed. Essentially granular structural fill soils should not be used as fill or overexcavation/backfill in pavement and exterior flatwork where partial removal of the Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 7 expansive lean clay soils will be completed due to the ability of those materials to pond and transmit water. All existing topsoil and vegetation should be removed from the building, pavement and exterior flatwork 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 the scarified soils should be adjusted to be within the range of -1 to +3% of standard Proctor optimum moisture content for the site lean clay and ±2% of standard Proctor optimum moisture content for essentially granular sand and gravel at the time of compaction. Fill and overexcavation/backfill materials consisting of the site lean clay, sand and gravel or imported structural fill should be placed in loose lifts not to exceed 9 inches thick, and compacted as outlined for the scarified subgrade soils above. Site lean clay fill should be adjusted to within the range of -1 to +3% of standard Proctor optimum moisture content while the site sand and gravel and imported structural fill should be adjusted to within ±2% of standard Proctor optimum moisture content at the time of placement and compaction. At the high end of the above recommended moisture content range, some pumping of the lean clay fill and overexcavation/backfill soils may be observed and would be expected. Care should be taken to maintain the proper moisture content in the subgrade soils prior to floor slab/exterior flatwork 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 subgrade soils, reworking of those materials or removal/replacement procedures may be required. Inherent risks exist when building in areas of expansive soils. The overexcavation/ backfill procedures outlined above will reduce but not eliminate the potential for movement of site pavements and exterior flatwork subsequent to construction. Some movement of lightly-loaded site pavements and exterior flatwork should be expected. Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 8 Storm Sewer Relocation At this time, we understand the existing storm sewer utility which crosses the subject property from north to south and essentially bisects the lot will be relocated as part of the site development. After removal of the storm sewer utility, we recommend suitable backfill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density for backfill depths of eight (8) feet or less. For utility backfill sections greater than eight (8) feet, we recommend backfill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted to at least 98% of the material’s standard Proctor maximum dry density. The site lean clay, sand and gravel and imported structural fill should be adjusted in moisture content as previously outlined in this report. Footing Foundations For design of footing foundations extended to bear on natural undisturbed site sand and gravel, we recommend using a maximum net allowable soil bearing pressure of 1,500 psf. A minimum dead load pressure would not be required for footing foundations extended to bear on non-expansive sand and gravel. If overexcavation/backfill procedures will be completed to redevelop foundation bearing, we recommend the footing 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 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 Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 9 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. We estimate settlement of footing foundations supported directly on natural undisturbed medium dense to very dense sand and gravel and resulting from the assumed structural loads would be less than ¾ inch. Differential settlement could approach the amount of total settlement estimated above. Seismicity Based on the results of our exploration and our review of the International Building Code (2003), a soil profile type D could be used for the site strata. Based on our review of United States Geologic Survey (USGS) mapped information, design spectral response acceleration values of SDS = .219 (21.9%) and S D1 = .093 (9.3%) could be used. Floor Slabs The building floor slab could be supported directly on the overexcavation/backfill material placed and compacted as outlined above. A modulus of subgrade reaction (k) value of 150 pci could be used for design of floor slabs supported on overexcavation/ backfill soils consisting of the on-site clay 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. Floor slabs should 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 car wash building partition walls supported above slabs-on-grade be constructed as floating walls to help reduce the potential for slab movement causing distress in upper sections of the building. A minimum 1½ inch void space is recommended beneath all partition walls. Special attention to door framing, drywall installation and trim carpentry should be taken to Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 10 isolate those elements from the floor slab, allowing for some differential foundation to floor slab movement to occur without transmitting stresses to the overlying structure. We do not expect floor coverings will be utilized in the car wash building. If anticipated and depending on the type of floor covering and floor covering adhesive used, a vapor barrier may be required immediately beneath the facility floor slab in those areas in order to maintain flooring product manufacturer warranties. A vapor barrier would help reduce the transmission of moisture through the floor slab. 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 and exterior flatwork subgrades should be developed as outlined in the “Floor Slab and Pavement/Exterior Flatwork Subgrade Development” section of this report. Concrete and asphalt pavements and exterior flatwork could be supported directly on the overexcavation/backfill soils placed and compacted as outlined in that section. Care should be taken to avoid disturbing the site fill and overexcavation/backfill soils prior to placement of site pavements and exterior flatwork. 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 and/or concrete placement. Some movement of site pavements and exterior flatwork 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 and Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 11 exterior flatwork to further reduce the potential for post-construction movement of those supported improvements. Care should be taken to ensure that when site pavements and exterior flatwork 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 areas of low volumes of automobiles and light trucks as well as areas of higher light vehicle traffic volumes 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 (greater than 1 inch) in flexible pavement areas should be mended prior to aggregate base course/asphalt placement. Isolated areas of subgrade instability can be mended on a case-by-case basis. If more extensive areas of subgrade instability are observed and depending on the in-place moisture content of the subgrade soils immediately prior to paving, the time of year when construction occurs and other hydrologic conditions, overall stabilization of the subgrade soils may become necessary to develop a suitable paving platform. If required, we recommend consideration be given to stabilization of the pavement subgrades with Class C fly ash. With the increase in support strength developed by the fly ash 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. Fly ash 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 fly ash- stabilized subgrade soils are outlined below in Table I. Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 12 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) Fly Ash 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 City of Fort Collins. Aggregate used in the asphaltic concrete should meet specific gradation requirements such as Colorado Department of Transportation (CDOT) grading S (¾-inch minus) or SX (½-inch minus) specifications. Hot mix asphalt designed using “Superpave” criteria should be compacted to within 92 to 96% of the materials Maximum Theoretical Density. Aggregate base should be consistent with CDOT requirements for Class 5 or Class 6 aggregate base, placed in loose lifts not to exceed 9 inches thick, adjusted to within ±2% of standard Proctor optimum moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density. If fly ash stabilization procedures will be completed, we recommend the addition of 12% Class ‘C’ fly ash based on component dry unit weights. A 12-inch thick stabilized zone should be constructed by thoroughly blending the fly ash with the in-place subgrade soils. Some “fluffing” of the finish subgrade level should be expected with the stabilization procedures. The blended materials should be adjusted in moisture content to within the range of ±2% of standard Proctor optimum moisture content and compacted to at least 95% of the material’s standard Proctor maximum dry density within two (2) hours of fly ash addition. For areas subjected to truck turning movements and/or concentrated and repetitive loading such as dumpster or truck parking and loading areas, we recommend consideration be given to the use of Portland cement concrete pavement with a minimum Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 13 thickness of 6 inches. The concrete used for site pavements should be entrained with 4% to 8% air and have a minimum 28-day compressive strength of 4,200 psi and maximum water cement ratio of 0.44. Woven wire mesh or fiber entrained concrete should be considered to help in the control of shrinkage cracking. The proposed pavement section designs do not include an allowance for excessive loading conditions imposed by heavy construction vehicles or equipment. Heavily loaded concrete or other building material trucks and construction equipment can cause some localized distress to site pavements. The recommended pavement sections are minimums and periodic maintenance efforts should be expected. A preventative maintenance program can help increase the service life of site pavements. Corrosive Soil Characteristics We measured the soluble sulfate concentration of two (2) representative samples of the subsoils which will likely be in contact with structural concrete. The sulfate concentrations measured in the samples varied from 0 to 150 parts per million. ACI rates the measured concentrations as being a negligible risk of concrete sulfate attack; therefore Type I cement should be suitable for concrete members on and below grade. As an added precaution, Type I/II Portland cement could be considered for additional sulfate resistance of construction concrete. Foundation concrete should be designed in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. 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. 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. Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 14 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/or flatwork 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 building 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 should also be retained to provide testing and observation services during construction to help determine that the design requirements are fulfilled. Geotechnical Subsurface Exploration Report Firehouse Xpress Car Wash #2 Lot 1 – Country Club Corners 5th Filing Fort Collins, Colorado Soilogic # 16-1328 15 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 BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 5" VEGETATION & TOPSOIL - 1 - CL LEAN CLAY WITH SAND 2 rust/brown/grey - very stiff 3 CS 19 13.3 111.5 9000+ 4.0% 9000 43 26 86.1% - 4 - 5 CS 31 5.8 - N/A - - - - - - SP-GP SAND AND GRAVEL 6 rust/brown - medium dense to dense 7 - 8 - 9 - 10 CS 50/10 6.1 - N/A - - - - - - 11 - 12 - 13 - 14 - 15 CS 38 10.5 - N/A - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-2 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 6" VEGETATION & TOPSOIL - CL LEAN CLAY WITH SAND - rust/brown 1 - 2 - SP-GP SAND AND GRAVEL 3 rust/brown - medium dense 4 - 5 CS 28 1.2 - N/A - - - - 8.2% - 6 - 7 - 8 - 9 - 10 CS 18 7.2 - N/A - - - - - - 11 - 12 - 13 - 14 - 15 CS 32 4.7 - N/A - - - - - BOTTOM OF BORING 15' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-3 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 6" VEGETATION & TOPSOIL - 1 CL LEAN CLAY WITH SAND - rust/brown 2 very stiff - 3 CS 29 10.4 99.7 9000+ 4.2% 4500 - - - - 4 - 5 CS 31 2.1 - N/A - - - - - SP-GP SAND AND GRAVEL - rust/brown 6 medium dense - 7 - 8 - 9 - 10 CS 38 7.8 - N/A - - - - - BOTTOM OF BORING 10' - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-4 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 6" VEGETATION & TOPSOIL - 1 - 2 CL LEAN CLAY WITH SAND - rust/brown 3 CS 22 11.3 111.3 9000+ 3.5% 3500 - - - stiff to very stiff - 4 - 5 CS 13 10.7 118.2 9000+ - - - - - - 6 - 7 - 8 SP-GP SAND AND GRAVEL - rust/brown 9 medium dense - 10 CS 32 7.6 - N/A - - - - - BOTTOM OF BORING 10' - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - LOG OF BORING B-5 1/1 CME 45 4" CFA Automatic BMc Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 5" VEGETATION & TOPSOIL - 1 CL LEAN CLAY - rust/brown/grey 2 very stiff - 3 CS 24 11.9 114.9 9000+ 6.9% 7500 37 20 93.8% - 4 - 5 CS 22 13.3 101.8 9000+ 0.8% 1250 - - - - 6 SP-GP SAND AND GRAVEL - rust/brown 7 very dense - 8 - 9 - 10 CS 50/5 - - N/A - - - - - BOTTOM OF BORING 10' - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - Liquid Limit 43 Plasticity Index 26 % Passing #200 86.1% Dry Density 111.5 pcf Final Moisture 19.7% % Swell @ 500 psf 4.0% Swell Pressure 9000 psf Sample ID: B-1 @ 2' Sample Description: Brown/Rust/Grey Lean Clay with Sand (CL) Initial Moisture 13.3% FIREHOUSE XPRESS CAR WASH #2 LOT 1 - COUNTRY CLUB CORNERS 5TH FILING, FORT COLLINS, COLORADO Project # 16-1328 January 2017 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 99.7 pcf Final Moisture 22.8% % Swell @ 150 psf 4.2% Swell Pressure 4500 psf Sample ID: B-3 @ 2' Sample Description: Brown/Rust Lean Clay with Sand (CL) Initial Moisture 10.4% FIREHOUSE XPRESS CAR WASH #2 LOT 1 - COUNTRY CLUB CORNERS 5TH FILING, FORT COLLINS, COLORADO Project # 16-1158 July 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 111.3 pcf Final Moisture 17.0% % Swell @ 150 psf 3.5% Swell Pressure 3500 psf Sample ID: B-4 @ 2' Sample Description: Brown/Rust Lean Clay with Sand (CL) Initial Moisture 11.3% FIREHOUSE XPRESS CAR WASH #2 LOT 1 - COUNTRY CLUB CORNERS 5TH FILING, FORT COLLINS, COLORADO Project # 16-1158 July 2016 SWELL/CONSOLIDATION TEST SUMMARY -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit 37 Plasticity Index 20 % Passing #200 93.8% Dry Density 114.9 pcf FIREHOUSE XPRESS CAR WASH #2 LOT 1 - COUNTRY CLUB CORNERS 5TH FILING, FORT COLLINS, COLORADO Project # 16-1158 July 2016 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-5 @ 2' Sample Description: Brown/Rust/Grey Lean Clay (CL) Initial Moisture 11.9% Final Moisture 20.0% % Swell @ 150 psf 6.9% Swell Pressure 7500 psf -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit - Plasticity Index - % Passing #200 - Dry Density 101.8 pcf FIREHOUSE XPRESS CAR WASH #2 LOT 1 - COUNTRY CLUB CORNERS 5TH FILING, FORT COLLINS, COLORADO Project # 16-1158 July 2016 SWELL/CONSOLIDATION TEST SUMMARY Sample ID: B-5 @ 4' Sample Description: Reddish Brown Sandy Lean Clay with Scattered Gravel (CL) Initial Moisture 13.3% Final Moisture 22.7% % Swell @ 150 psf 0.8% Swell Pressure 1250 psf -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 Clean Gravels Cu ! 4 and 1 " Cc " 3E GW Well graded gravelF Less than 5% finesC Cu < 4 and/or 1 > Cc > 3E GP Poorly graded gravelF Fines classify as ML or MH GM Silty gravelF,G, H Coarse Grained Soils More than 50% retained on No. 200 sieve Gravels More than 50% of coarse fraction retained on No. 4 sieve Gravels with Fines More than 12% finesC Fines classify as CL or CH GC Clayey gravelF,G,H Clean Sands Cu ! 6 and 1 " Cc " 3E SW Well graded sandI Less than 5% finesD Cu < 6 and/or 1 > Cc > 3E SP Poorly graded sandI Fines classify as ML or MH SM Silty sandG,H,I Sands 50% or more of coarse fraction passes No. 4 sieve Sands with Fines More than 12% finesD Fines classify as CL or CH SC Clayey sandG,H,I Silts and Clays PI > 7 and plots on or above “A” lineJ CL Lean clayK,L,M Liquid limit less than 50 Inorganic PI < 4 or plots below “A” lineJ ML SiltK,L,M Liquid limit - oven dried Organic clayK,L,M,N Fine-Grained Soils 50% or more passes the No. 200 sieve Organic Liquid limit - not dried < 0.75 OL Organic siltK,L,M,O Inorganic PI plots on or above “A” line CH Fat clayK,L,M Silts and Clays Liquid limit 50 or more PI plots below “A” line MH Elastic siltK,L,M Organic Liquid limit - oven dried Organic clayK,L,M,P Liquid limit - not dried < 0.75 OH Organic siltK,L,M,Q Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-in. (75-mm) sieve B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name. C Gravels with 5 to 12% fines require dual symbols: GW-GM well graded gravel with silt, GW-GC well graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay. D Sands with 5 to 12% fines require dual symbols: SW-SM well graded sand with silt, SW-SC well graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay E Cu = D60/D10 Cc = GENERAL NOTES DRILLING & SAMPLING SYMBOLS: SS: Split Spoon - 1⅜" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger ST: Thin-Walled Tube – 2.5" O.D., unless otherwise noted PA: Power Auger RS: Ring Sampler - 2.42" I.D., 3" O.D., unless otherwise noted HA: Hand Auger CS: California Barrel - 1.92" I.D., 2.5" O.D., unless otherwise noted RB: Rock Bit BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary The number of blows required to advance a standard 2-inch O.D. split-spoon sampler (SS) the last 12 inches of the total 18-inch penetration with a 140-pound hammer falling 30 inches is considered the “Standard Penetration” or “N-value”. For 2.5” O.D. California Barrel samplers (CB) the penetration value is reported as the number of blows required to advance the sampler 12 inches using a 140-pound hammer falling 30 inches, reported as “blows per inch,” and is not considered equivalent to the “Standard Penetration” or “N-value”. WATER LEVEL MEASUREMENT SYMBOLS: WL: Water Level WS: While Sampling WCI: Wet Cave in WD: While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB: After Boring ACR: After Casing Removal Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-term observations. DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency. FINE-GRAINED SOILS COARSE-GRAINED SOILS BEDROCK (CB) Blows/Ft. (SS) Blows/Ft. Consistency (CB) Blows/Ft. (SS) Blows/Ft. Relative Density (CB) Blows/Ft. (SS) Blows/Ft. Consistency < 3 0-2 Very Soft 0-5 < 3 Very Loose < 24 < 20 Weathered 3-5 3-4 Soft 6-14 4-9 Loose 24-35 20-29 Firm 6-10 5-8 Medium Stiff 15-46 10-29 Medium Dense 36-60 30-49 Medium Hard 11-18 9-15 Stiff 47-79 30-50 Dense 61-96 50-79 Hard 19-36 16-30 Very Stiff > 79 > 50 Very Dense > 96 > 79 Very Hard > 36 > 30 Hard RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY Descriptive Terms of Other Constituents Percent of Dry Weight Major Component of Sample Particle Size Trace < 15 Boulders Over 12 in. (300mm) With 15 – 29 Cobbles 12 in. to 3 in. (300mm to 75 mm) Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75 mm) Sand Silt or Clay #4 to #200 sieve (4.75mm to 0.075mm) Passing #200 Sieve (0.075mm) RELATIVE PROPORTIONS OF FINES PLASTICITY DESCRIPTION Descriptive Terms of Other Constituents Percent of Dry Weight Term Plasticity Index Trace With Modifiers < 5 5 – 12 > 12 Non-plastic Low Medium High 0 1-10 11-30 30+ F If soil contains ! 15% sand, add “with sand” to group name. G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM. HIf fines are organic, add “with organic fines” to group name. I If soil contains ! 15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant. L If soil contains ! 30% plus No. 200 predominantly sand, add “sandy” to group name. M If soil contains ! 30% plus No. 200, predominantly gravel, add “gravelly” to group name. N PI ! 4 and plots on or above “A” line. O PI < 4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line. 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 24 Hours After Drilling 8' USCS Sampler Atterberg Limits Start Date 12/22/2017 Auger Type: During Drilling 8' Finish Date 12/22/2017 Hammer Type: After Drilling 8' FIREHOUSE XPRESS CAR WASH #2 LOT 1 - COUNTRY CLUB CORNERS 5TH FILING, FORT COLLINS, COLORADO Project # 16-1328 January 2017 Sheet Drilling Rig: Water Depth Information 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 24 Hours After Drilling 7.5' USCS Sampler Atterberg Limits Start Date 12/22/2017 Auger Type: During Drilling 7' Finish Date 12/22/2017 Hammer Type: After Drilling 7' FIREHOUSE XPRESS CAR WASH #2 LOT 1 - COUNTRY CLUB CORNERS 5TH FILING, FORT COLLINS, COLORADO Project # 16-1328 January 2017 Sheet Drilling Rig: Water Depth Information 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 24 Hours After Drilling 6.5' USCS Sampler Atterberg Limits Start Date 12/22/2017 Auger Type: During Drilling 8' Finish Date 12/22/2017 Hammer Type: After Drilling 8' FIREHOUSE XPRESS CAR WASH #2 LOT 1 - COUNTRY CLUB CORNERS 5TH FILING, FORT COLLINS, COLORADO Project # 16-1328 January 2017 Sheet Drilling Rig: Water Depth Information 26 - 27 - 28 - 29 - 30 FIREHOUSE XPRESS CAR WASH #2 LOT 1 - COUNTRY CLUB CORNERS 5TH FILING, FORT COLLINS, COLORADO Project # 16-1328 January 2017 Sheet Drilling Rig: Water Depth Information Start Date 12/22/2017 Auger Type: During Drilling 7' Finish Date 12/22/2017 Hammer Type: After Drilling 7' Surface Elev. - Field Personnel: 24 Hours After Drilling 7' USCS Sampler Atterberg Limits 26 - 27 - 28 - 29 - 30 Surface Elev. - Field Personnel: 24 Hours After Drilling DCI @ 7' USCS Sampler Atterberg Limits Start Date 12/22/2017 Auger Type: During Drilling 8.5' Finish Date 12/22/2017 Hammer Type: After Drilling 8.5' FIREHOUSE XPRESS CAR WASH #2 LOT 1 - COUNTRY CLUB CORNERS 5TH FILING, FORT COLLINS, COLORADO Project # 16-1328 January 2017 Sheet Drilling Rig: Water Depth Information