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HomeMy WebLinkAboutVOICE OF TRUTH TABERNACLE - PDP200011 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGEOTECHNICAL SUBSURFACE EXPLORATION REPORT VOICE OF TRUTH TABERNACLE LOT 1, VOICE OF TRUTH TABERNACLE SUBDIVISION 1108 NORTH TIMBERLINE ROAD FORT COLLINS, COLORADO SOILOGIC # 19-1028 January 30, 2020 Soilogic, Inc. 3522 Draft Horse Court • Loveland, CO 80538 • (970) 535-6144 January 30, 2020 Voice of Truth Tabernacle 1132 Sawtooth Oak Court Fort Collins, Colorado 80525 Attn: Mr. Tito Moreira Re: Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle Lot 1, Voice of Truth Tabernacle Subdivision – 1108 North Timberline Road Fort Collins, Colorado Soilogic Project # 19-1028 Mr. Moreira: Soilogic, Inc. (Soilogic) personnel have completed the geotechnical subsurface exploration you requested for the proposed Voice of Truth Tabernacle building and associated site improvements to be constructed on a portion of Lot 1, Voice of Truth Tabernacle Subdivision 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 a thin mantle of vegetation and topsoil underlain by light brown/brown lean clay with varying amounts of sand. The lean clay varied from medium stiff to hard in terms of consistency, generally exhibited no to low swell potential (although one (1) sample of lean clay obtained from boring B-1 at a depth of approximately 2 feet below ground surface exhibited moderate swell potential) at current moisture and density conditions and extended to the bottom all borings at depths ranging from approximately 5 to 15 feet below present site grade. Groundwater was not encountered in the completed site borings at the time of drilling. Based on the subsurface conditions encountered, results of laboratory testing and type of construction proposed, it is our opinion the proposed church building could be supported by conventional spread footing foundations bearing on natural, undisturbed lean clay with low swell potential and/or properly placed and compacted fill and/or overexcavation/ backfill (if/where required). The presence of near-surface moderately expansive lean clay at the location of boring B-1 completed in the proposed church building area will Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road, Fort Collins, Colorado Soilogic # 19-1028 2 require care in mitigating those soils prior to foundation and flor slab construction. If identified to any appreciable extent at the time of construction, extending footing foundations through these soils to bear on low swelling clays at greater depth and/or overexcavation/backfill procedures will be required. The exact depth and extent of any required overexcavation/backfill procedures can best be established at the time of construction through openhole/test pit observation. The site soils would be considered LVC and could be used as fill and overexcavation/backfill (if required) to develop the site. The reconditioned near-surface site lean clay and properly placed and compacted fill and overexcavation/backfill consisting of on-site lean clay or approved low volume change (LVC) import soils could be used for support of the building floor slabs, exterior flatwork and site asphalt and/or concrete pavements. Pavement section design options for the site drive and parking area pavements are included with this report. Other opinions and recommendations concerning design criteria and construction details for the proposed site improvements are also provided. 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: Zach Gordon, E.I. Wolf von Carlowitz, P.E. Project Engineer Principal Engineer GEOTECHNICAL SUBSURFACE EXPLORATION REPORT VOICE OF TRUTH TABERNACLE LOT 1, VOICE OF TRUTH TABERNACLE SUBDIVISION 1108 NORTH TIMBERLINE FORT COLLINS, COLORADO SOILOGIC # 19-1028 January 30, 2020 INTRODUCTION This report contains the results of the completed geotechnical subsurface exploration for the proposed Voice of Truth Tabernacle church and associated site improvements to be constructed on a portion of Lot 1, Voice of Truth Tabernacle Subdivision 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 church foundation and support of floor slabs, exterior flatwork and site pavements. Pavement section design options 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 Based on the provided site plan and discussion with the client, we understand the church building will be a partial two-story steel frame structure constructed as slab-on-grade and with a partial basement area. Foundation loads for the building are expected to be relatively light, with continuous wall loads less than 3.5 kips per lineal foot and individual column loads less than 75 kips. As part of the proposed site improvements, we understand associated exterior flatwork and site drive and parking area pavements will be constructed. Traffic loading on the site pavements is expected to include areas of both low volumes of automobiles and light trucks as well as areas of higher light-vehicle traffic volumes and occasional heavy truck traffic. Small grade changes are expected to develop finish site grades for the proposed development. Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 2 SITE DESCRIPTION The project site includes an approximate 2.39-acre parcel of land described as Lot 1, Voice of Truth Tabernacle Subdivision, located at 1108 North Timberline Road in Fort Collins, Colorado. The proposed development will be completed to the north of the existing site residence. At the time of our site exploration, a majority of the site was undeveloped/vacant and contained a sparse to moderate growth of grass and weed vegetation. The site was observed to be relatively level across the property, with the maximum difference in ground surface elevation across the property estimated to be less than 2 feet. Evidence of prior building construction was not observed in the proposed construction areas 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 five (5) soils borings were extended to depths ranging from approximately 5 to 15 feet below present site grade. Two (2) soil borings were completed in the approximate church building footprint, with one (1) boring completed in the future church building area and two (2) additional borings completed in proposed drive and parking areas. The boring locations were established in the field by Soilogic personnel based on a provided site plan and by 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 outlined on this diagram should be considered accurate only to the degree implied by the methods used to make the field measurements. Graphic logs of each of the auger borings are also included. The test holes were advanced using 4-inch diameter, continuous-flight auger powered by a truck-mounted CME-45 drill rig. Samples of the subsurface materials were obtained at regular intervals using California barrel sampling procedures in general accordance with ASTM specification D-1586. As part of the D-1586 sampling procedure, standard sampling barrel is driven into the substrata using a 140-pound hammer falling a distance Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 3 of 30 inches. The number of blows required to advance the sampler a distance of 12 inches is recorded and helpful in estimating the consistency, relative density or hardness of the soils and/or bedrock encountered. In the California barrel sampling procedure, relatively undisturbed samples are obtained in removable brass liners. Samples of the subsurface materials obtained in the field were sealed and returned to the laboratory for further evaluation, classification and testing. Laboratory Testing The samples collected were tested in the laboratory to measure natural moisture content and were visually 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 were conducted to evaluate soil volume change potential under loading and saturation conditions. As part of the laboratory testing, water soluble sulfate tests were completed on selected soil samples to evaluate corrosive soil characteristics with respect to buried concrete. The results of the completed laboratory tests are discussed subsequently in this report and outlined on the attached boring logs and swell/consolidation test summaries. SUBSURFACE CONDITIONS The subsurface materials encountered in the completed site borings consisted of a thin mantle of vegetation and topsoil underlain by light brown/brown lean clay with varying amounts of sand. The lean clay varied from medium stiff to hard in terms of consistency, Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 4 generally exhibited no to low swell potential (although one (1) sample of lean clay obtained from boring B-1 at a depth of approximately 2 feet below ground surface exhibited moderate swell potential) at current moisture and density conditions and extended to the bottom all borings at depths ranging from approximately 5 to 15 feet below present site grade. Groundwater was not encountered in the completed site borings at the time of drilling. The stratigraphy indicated on the included boring logs represents the approximate location of changes in soil and bedrock types. Actual changes may be more gradual than those indicated. Groundwater was not encountered in the completed site borings at the time of drilling. 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. General In general, the light brown/brown site lean clay soils encountered across a majority of the site exhibited no to low swell potential at current moisture and density conditions. Dark brown, hard lean clay which exhibited moderate swell potential was encountered at a depth of approximately 2 feet below ground surface at the location of boring B-1 completed at the approximate northeast corner of the proposed church building and may be present near-surface at other locations within the building footprint. Careful evaluation of the depth and extent of moderately expansive dry and hard dark brown clay should be completed at the time of construction through openhole/test pit observation. If more extensive zones of moderately expansive dark brown lean clay are observed extending below the proposed foundation and floor slab subgrade elevations, extending footing foundations through these materials to bear on low swelling clays at greater depth and Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 5 completing overexcavation/backfill procedures beneath building floor slabs will be required. Low-swelling lean clay soils are anticipated at depths between about 3 to 4 feet below ground surface in the area of boring B-1. The exact depth and extent of the moderately expansive site lean clay can best be established at the time of construction through openhole/test pit observation. Site Development All existing vegetation and topsoil should be completely removed from the building, exterior flatwork, pavement and any proposed fill areas. The moderately expansive dark brown lean clay encountered in boring B-1 should also be removed to low-swelling lean clay levels from beneath the church building footprint and to a minimum depth of 2 feet from below exterior flatwork and site pavements at this time. As previously outlined, the depth and extent of required expansive soil removal (if any) can best be established at the time of site development/excavation through test pit and/or openhole observation. After stripping and completing all cuts and overexcavation procedures and prior to the placement of any new fill, overexcavation/backfill or overlying improvements, Soilogic recommends the exposed subgrade soils be scarified to a depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the materials standard Proctor maximum dry density. The moisture content of the scarified subgrade soils should be adjusted to within the range of -1 to +3% or standard Proctor optimum moisture content at the time of placement and compaction. Fill and overexcavation/backfill soils required to develop the site should consist of approved low volume change (LVC) soils free from organic matter, debris and other objectionable materials. Based on results of the completed laboratory testing, it is our opinion the site lean clay could be used as fill and overexcavation/backfill to develop the site. If it is necessary to import additional material to the site for use as fill, those materials should consist of approved LVC and relatively impervious materials and be approved prior to use. Typically soils with a liquid limit less than 40 and a plasticity index less than 18 could be considered LVC. Import soils should contain a minimum of 25% fines (material passing the #200 size sieve) in order to reduce permeability. We recommend the site lean clay and/or similar materials be placed in loose lifts not to Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 6 exceed 9 inches thick, adjusted in moisture content and compacted as recommended for the scarified subgrade soils above. Care should be taken to avoid disturbing the reconditioned subgrade soils and placed fill/ overexcavation/backfill 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 church building could be supported by continuous spread footing and isolated pad foundations bearing on natural, undisturbed, stiff to hard lean clay with low swell potential or properly placed and compacted fill or overexcavation/backfill (if required). Care should be taken at the time of construction to ensure all footing foundations bear on like materials with suitable strength and low volume change potential. If more extensive zones of moderately expansive lean clay soils are encountered at that time, extending footing foundations through moderately expansive lean clay soils to bear on lean clay with low swell potential at slightly greater depth than is typical may be required. For design of foundations bearing on natural, undisturbed, stiff to hard lean clay and/or suitable fill or overexcavation/backfill compacted to at least 95% of the material’s standard Proctor maximum dry density, we recommend using a maximum net allowable soil bearing pressure of 1,500 psf. As a precaution, we recommend footing foundations be designed to maintain a minimum dead load pressure of 500 psf 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. Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 7 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. Backfill placed adjacent to foundation walls should consist of LVC potential and relatively impervious soils free from organic matter, debris and other objectionable materials. Native site lean clay could be used as backfill in these areas provided the proper moisture content is developed in those materials at the time of placement and compaction. We recommend the native site lean clay and/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. Excessive lateral stresses can be imposed on unilaterally backfilled foundation walls when using heavier mechanical compaction equipment. We recommend compaction of unbalanced foundation wall backfill soils be completed using light mechanical or hand compaction equipment. Seismic Design Based on the results of this investigation and Soilogic’s review of the International Building Code (IBC - 2015), 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 = 0.192 and SD1 = 0.092 could be used. Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 8 Below Grade Construction We recommend a perimeter drain system be installed around all below-grade areas to help reduce the potential for water infiltration into the basement area and/or the development of hydrostatic pressures behind the below-grade walls. A perimeter drain system should consist of a 4-inch diameter perforated drain pipe surrounded by a minimum of six (6) inches of free-draining gravel. A filter fabric should be installed around the free-draining gravel or perforated pipe to reduce the potential for an influx of fine-grained soils into the system. The invert of the drain pipe, at its high point, should be placed at approximate foundation bearing levels, run around the exterior perimeter of the below-grade area with a minimum slope of ⅛-inch per foot to facilitate efficient water removal and should discharge to sump pump and pit system. Care should be taken during perimeter drain installation to avoid disturbing those soils providing support to the residence footing foundations (extending down at a 1:1 slope from the bottom edges of the footings). Floor Slabs and Exterior Flatwork In the basement area, the floor slab could be supported directly on natural undisturbed site lean clay with low swell potential. At-grade floor slabs and exterior flatwork could be supported directly on reconditioned natural site soils and/or properly placed and compacted fill or overexcavation/backfill (if required) developed as outlined in the “Site Development” section of this report. A modulus of subgrade reaction (k) value of 150 pci could be used for design of floor slabs supported on reconditioned natural site lean clay or similar LVC fill materials. 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 and exterior flatwork 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 Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 9 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 slabs, 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 slabs to maintain flooring product manufacturer warranties. A vapor barrier would help reduce the transmission of moisture through 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 and proper placement and curing procedures. Slab curl cannot be eliminated. Soilogic recommends 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. Exterior flatwork will experience some movement subsequent to construction as the subgrade soils increase in moisture content. Based on results of the completed field and laboratory testing, we expect the amount of movement of exterior flatwork supported on reconditioned natural site soils and/or properly placed and compacted fill and overexcavation/backfill (if required) would be limited. Site Pavements Pavement subgrades should be developed as outlined in the “ Site Development” section of this report. Site pavements could be supported directly on the reconditioned subgrade soils and/or suitable fill and overexcavation/backfill soils placed and compacted as outlined in that section. Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 10 The pavement subgrades are expected to consist of reconditioned lean clay. The lean clay soils classify as A-6 soils in accordance with the American Association of State and Highway Transportation Officials (AASHTO) classification system and would be subject to low remolded shear strength. A resistance value (R-value) of 5 was estimated for the lean clay subgrade soils and used in the pavement section design. Traffic loading on the site pavements is expected to consist of areas of low volumes of automobiles and light trucks, as well as areas of higher light vehicle traffic volumes and occasional heavier trash and delivery trucks. Equivalent 18-kip single axle loads (ESAL’s) were estimated for the quantity of site traffic anticipated. Two (2) general pavement design categories are outlined below in Table I. Standard duty pavements could be considered in automobile drive and parking areas. Heavy duty pavements should be considered for access drives and other areas of the site expected to receive higher traffic volumes or heavy truck traffic. Proofrolling of the pavement subgrades should be completed to help identify unstable areas. Areas which pump or deform excessively should be stabilized prior to asphalt, PCC or aggregate base course placement. 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, stabilization of the subgrade soils may become necessary to develop a suitable paving platform. Isolated areas of instability can be mended on a case by case basis. If more extensive areas of subgrade instability are observed at the time of construction, overall chemical stabilization of the pavement subgrade soils could be completed to develop a suitable paving platform. If required, we recommend consideration be given to stabilization of the pavement subgrades with Class C fly ash. With the increase in support strength developed by the chemical stabilization procedures, it is our opinion some credit for the stabilized zone could be included in the pavement section design, reducing the required thickness of overlying asphaltic concrete and aggregate base course. Chemical stabilization can also eliminate some of the uncertainty associated with attempting to pave during periods of inclement weather. Pavement section design options incorporating some structural credit for the fly-ash stabilized subgrade soils are outlined below in Table 1. Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 11 TABLE 1 – PAVEMENT SECTION DESIGN Standard Duty Heavy Duty Option A – Composite Asphaltic Concrete (Grading S or SX) Aggregate Base (Class 5 or 6) 4” 6” 5” 8” Option B – Composite on Stabilized Subgrade Asphaltic Concrete (Grading S or SX) Aggregate Base (Class 5 or 6) 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 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 based on component dry unit weights. A 12-inch thick stabilized zone should be constructed by thoroughly blending the fly ash with the in-place subgrade soils. Some “fluffing” of the finish subgrade level should be expected with the stabilization procedures. The blended materials should be adjusted in moisture content to within the range of ±2% of standard Proctor optimum moisture content and compacted to at least 95% of the material’s standard Proctor maximum dry density within two (2) hours of fly ash addition. For areas subjected to truck turning movements and/or concentrated and repetitive loading such as dumpster or truck parking and loading areas, we recommend consideration be given to the use of Portland cement concrete pavement with a minimum thickness of 6 inches. The concrete used for site pavements should be air entrained and Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 12 have a 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. Areas of the site expected to receive higher volumes of heavy truck traffic may require thicker pavement sections. We would be happy to complete a pavement section design based on the actual type and quantity of heavy truck traffic anticipated. 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 fell within the range of 0 to 0.1% by weight in soil. ACI rates the measured concentrations as being defined as a “negligible risk” category for concrete sulfate attack; therefore, Type I cement should be suitable for concrete members on and below grade. As an added precaution, Type I/II Portland cement could be considered for additional sulfate resistance of site concrete. Structural 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 church building, 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 Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 13 some settlement of the building backfill soils occurs over time, the original grade and associated positive drainage outlined above should be immediately restored. Care should be taken in the planning of landscaping to avoid features which could result in the fluctuation of the moisture content of the foundation bearing and flatwork and pavement subgrade soils. We recommend watering systems be placed a minimum of 5 feet away from the perimeter of the site 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 structures, 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 Geotechnical Subsurface Exploration Report Voice of Truth Tabernacle – Lot 1, Voice of Truth Tabernacle Subdivision 1108 North Timberline Road Fort Collins, Colorado Soilogic # 19-1028 14 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 JL / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3-6" VEGETATION & TOPSOIL - 1 - 2 - 3 CS 37 13.0 100.6 9000+ 4.3% 3200 - - - - 4 - 5 CS 26 11.1 109.2 9000+ 2.3% 2000 39 22 62.8% - 6 - CL SANDY LEAN CLAY 7 light brown, brown - medium stiff to hard 8 - 9 - 10 CS 11 11.9 111.4 9000+ - - - - - - 11 - 12 - 13 - 14 - 15 CS 8 14.7 115.2 6500 - - - - - BOTTOM OF BORING @ 15.0' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 VOICE OF TRUTH TABERNACLE 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO LOG OF BORING B-2 1/1 CME 45 4" CFA Automatic JL / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3-6" VEGETATION & TOPSOIL - 1 - 2 - 3 CS 17 7.6 102.5 9000+ 1.2% - - - - - 4 - 5 CS 20 7.4 111.5 9000+ 1.5% 1600 - - - - 6 - CL SANDY LEAN CLAY 7 light brown, brown - medium stiff to very stiff 8 - 9 - 10 CS 9 13.3 108.4 9000+ - - - - - - 11 - 12 - 13 - 14 - 15 CS 10 14.4 113.2 9000 - - - - - BOTTOM OF BORING @ 15.0' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig: Water Depth Information VOICE OF TRUTH TABERNACLE LOG OF BORING B-3 1/1 CME 45 4" CFA Automatic JL / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3-6" VEGETATION & TOPSOIL - 1 - 2 - 3 - 4 - 5 CS 17 8.6 104.3 9000+ 1.1% - - - - - 6 - CL SANDY LEAN CLAY 7 light brown, brown - medium stiff to stiff 8 - 9 - 10 CS 14 15.2 112.0 9000+ 0.8% 1800 - - - - 11 - 12 - 13 - 14 - 15 CS 10 15.1 114.0 6000 - - - - - BOTTOM OF BORING @ 15.0' - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig: Water Depth Information VOICE OF TRUTH TABERNACLE LOG OF BORING B-4 1/1 CME 45 4" CFA Automatic JL / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3-6" VEGETATION & TOPSOIL - 1 - 2 - 3 CS 26 7.2 0.0 9000+ 1.2% - - - - - 4 - CL SANDY LEAN CLAY 5 CS 27 8.7 102.4 9000+ 0.7% - 34 17 54.2% light brown, brown - very stiff 6 - 7 - 8 - 9 - 10 CS 20 6.9 108.2 9000+ - - - - - BOTTOM OF BORING @ 10.0' - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 Sheet Drilling Rig: Water Depth Information VOICE OF TRUTH TABERNACLE LOG OF BORING B-5 1/1 CME 45 4" CFA Automatic JL / BM Estimated Swell % Passing SOIL DESCRIPTION Depth "N" MC DD qu % Swell @ Pressure # 200 Sieve (ft) (%) (pcf) (psf) 500 psf (psf) LL PI (%) 3-6" VEGETATION & TOPSOIL - 1 - 2 CL SANDY LEAN CLAY - light brown, brown 3 CS 23 8.7 108.8 9000+ 2.0% 1700 - - - stiff to very stiff - 4 - 5 CS 16 9.9 107.7 9000+ - - - - - 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 VOICE OF TRUTH TABERNACLE Liquid Limit - Plasticity Index - % Passing #200 - Dry Density (pcf) 100.6 500 Final Moisture 21.7% % Swell @ 500 psf 4.3% Swell Pressure (psf) 3,200 Sample ID: B-1 @ 2 Sample Description: Light Brown/Brown Sandy Lean Clay (CL) Initial Moisture 13.0% SWELL/CONSOLIDATION TEST SUMMARY VOICE OF TRUTH TABERNACLE 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit 39 Plasticity Index 22 % Passing #200 62.8% Dry Density (pcf) 109.2 500 Final Moisture 20.9% % Swell @ 500 psf 2.3% Swell Pressure (psf) 2,000 Initial Moisture 11.1% Sample ID: B-1 @ 4 Sample Description: Light Brown/Brown Sandy Lean Clay (CL) SWELL/CONSOLIDATION TEST SUMMARY VOICE OF TRUTH TABERNACLE 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 -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) 102.5 500 Final Moisture 21.9% % Swell @ 500 psf 1.2% Swell Pressure (psf) - Initial Moisture 7.6% Sample ID: B-2 @ 2 Sample Description: Light Brown/Brown Sandy Lean Clay (CL) (Swell Only) SWELL/CONSOLIDATION TEST SUMMARY VOICE OF TRUTH TABERNACLE 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 -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) 111.5 500 Final Moisture 20.9% % Swell @ 500 psf 1.5% Swell Pressure (psf) 1,600 Initial Moisture 7.4% Sample ID: B-2 @ 4 Sample Description: Light Brown/Brown Sandy Lean Clay (CL) SWELL/CONSOLIDATION TEST SUMMARY VOICE OF TRUTH TABERNACLE 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 -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) 104.3 500 Final Moisture 22.3% % Swell @ 500 psf 1.1% Swell Pressure (psf) - Initial Moisture 8.6% Sample ID: B-3 @ 4 Sample Description: Light Brown/Brown Sandy Lean Clay (CL) (Swell Only) SWELL/CONSOLIDATION TEST SUMMARY VOICE OF TRUTH TABERNACLE 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 -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) 112.0 500 Final Moisture 17.7% % Swell @ 500 psf 0.8% Swell Pressure (psf) 1,800 Initial Moisture 15.2% Sample ID: B-3 @ 9 Sample Description: Light Brown/Brown Sandy Lean Clay (CL) SWELL/CONSOLIDATION TEST SUMMARY VOICE OF TRUTH TABERNACLE 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 -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) 0.0 500 Final Moisture 23.5% % Swell @ 500 psf 1.2% Swell Pressure (psf) - Initial Moisture 7.2% Sample ID: B-4 @ 2 Sample Description: Light Brown/Brown Sandy Lean Clay (CL) (Swell Only) SWELL/CONSOLIDATION TEST SUMMARY VOICE OF TRUTH TABERNACLE 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 10 100 1000 10000 100000 --------- Applied Load (psf) Liquid Limit 34 Plasticity Index 17 % Passing #200 54.2% Dry Density (pcf) 102.4 500 Final Moisture 23.3% % Swell @ 500 psf 0.7% Swell Pressure (psf) - Initial Moisture 8.7% Sample ID: B-4 @ 4 Sample Description: Light Brown/Brown Sandy Lean Clay (CL) (Swell Only) SWELL/CONSOLIDATION TEST SUMMARY VOICE OF TRUTH TABERNACLE 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 -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) 108.8 500 Final Moisture 20.6% % Swell @ 500 psf 2.0% Swell Pressure (psf) 1,700 Initial Moisture 8.7% Sample ID: B-5 @ 2 Sample Description: Light Brown/Brown Sandy Lean Clay (CL) SWELL/CONSOLIDATION TEST SUMMARY VOICE OF TRUTH TABERNACLE 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 -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. 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 USCS Sampler Atterberg Limits Start Date 2/27/2019 Auger Type: During Drilling None Finish Date 2/27/2019 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 24 Hours After Drilling - 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 USCS Sampler Atterberg Limits Start Date 2/27/2019 Auger Type: During Drilling None Finish Date 2/27/2019 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 24 Hours After Drilling - 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 USCS Sampler Atterberg Limits Start Date 2/27/2019 Auger Type: During Drilling None Finish Date 2/27/2019 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 24 Hours After Drilling - 1108 NORTH TIMBERLINE ROAD, FORT COLLINS, COLORADO Project # 19-1028 March 2019 USCS Sampler Atterberg Limits Start Date 2/27/2019 Auger Type: During Drilling None Finish Date 2/27/2019 Hammer Type: After Drilling None Surface Elev. - Field Personnel: 24 Hours After Drilling - Project # 19-1028 March 2019 Sheet Drilling Rig: Water Depth Information Start Date 2/27/2019 Auger Type: During Drilling None Finish Date 2/27/2019 Hammer Type: After Drilling None USCS Sampler Atterberg Limits Surface Elev. - Field Personnel: 24 Hours After Drilling -