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HomeMy WebLinkAboutJAX MERCANTILE COMPNAY PHASE 1 1200 NORTH COLLEGE - Filed GR-GEOTECHNICAL REPORT/SOILS REPORT -GEOTECHNICAL EXPLORATION REPORT JAX MERCANTILE IMPROVEMENTS FORT COLLINS, COLORADO SOILOGIC # 09-1025 October 20, 2009 SO;"Locslc Sologic, Inc. va SOILOGIC October 20, 2009 Jax Mercantile Company c/o Shear Engineering Corporation 4836 South College Avenue, Suite 12 Fort Collins, Colorado 80525 Attn: Mr. Cody Geisendorfer Re: Geotechnical Exploration Report Jax Mercantile Improvements (1200 North College Avenue) Fort Collins, Colorado Soilogic Project # 09-1025 Mr. Geisendorfer: Soilogic, Inc. (Soilogic) personnel have completed the geotechnical subsurface exploration you requested for the proposed Jax Mercantile addition and associated site improvements to be constructed 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 topsoil and vegetation underlain by brown lean clay with varying amounts of silt and sand. The lean clay was medium stiff to stiff in consistency near surface becoming softer with depth and showed low swell potential at in situ moisture and density conditions. The site lean extended to depths ranging from approximately 5%2 to 6 feet below ground surface and was underlain by brown sand with gravel. The sand and gravel was medium dense to dense and extended to the bottom of boring at depths ranging from approximately 10 to 15 feet below present site grades. Groundwater was encountered in the completed site borings at a depth of approximately 6 feet below ground surface at the time of drilling. Groundwater was measured at a depth of approximately 5.5 feet below ground surface in borehole B-2 after the completion of drilling. Based on the subsurface conditions encountered, results of laboratory testing and type of construction proposed, it is our opinion the proposed addition could be constructed with Soilogic, Inc. 1435 Hilltop Circie a Windsor, CO 80550 • (970) 674-3430 PO Box 772716 a Steamboat Springs, CO •80477 0 (970) 276-2087 Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 2 conventional spread footing foundations bearing on medium stiff lean clay. The reconditioned near surface site soils or properly placed and compacted fill could also be used for support of the addition floor slab, exterior flatwork and site pavements. Soft clay soils encountered with depth and the potential for uncontrolled backfill soils within the addition area will require care during construction to help insure the addition footing foundations and floor slab will be supported on like materials with suitable strength. If more extensive zones of soft clay soils or uncontrolled fill are e3ncountered at the time of excavation, some overexcavationlbackfill procedures may be required to redevelop suitable foundation bearing and floor slab support. Other opinions and recommendations concerning design criteria and construction details for the proposed site improvements are included with this report. Pavement section design estimates for the widening of North College Avenue and construction of Jerome 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 be of further assistance to you in any way, please do not hesitate to contact us. Very Truly Yours, Soilogic, Inc. Wo: Prim GEOTECHNICAL EXPLORATION REPORT JAX MERCANTILE IMPROVEMENTS FORT COLLINS, COLORADO SOILOGIC # 09-1025 October 20, 2009 INTRODUCTION This report contains the results of the completed geotechnical subsurface exploration for the Jax Mercantile improvements to be constructed in Fort Collins, Colorado. The purpose of our investigation was to describe the subsurface conditions encountered in the completed site borings and develop the test data necessary to provide recommendations concerning design and construction of the building `E' addition foundation and support of the addition floor slab, site pavements and exterior flatwork. Pavement section design options for the site are also included along with pavement section design estimates for the widening of North College Avenue and the construction of Jerome. The conclusions and recommendations outlined in this report are based on results of the completed field and laboratory testing and our experience with subsurface conditions in this area. PROPOSED CONSTRUCTION We understand the proposed addition will have a plan area of approximately 3,000 square feet. The addition is expected to be a single story wood frame structure constructed as slab on grade consistent with the existing structure. 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 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 site is located at 1200 North College Avenue in Fort Collins, Colorado. At the time of our exploration, the proposed improvement areas were vegetated and relatively flat with the maximum difference in ground surface elevation across the addition and pavement areas estimated to be less than 3 feet. We understand some excavation may have been completed previously in the proposed addition area. Evidence Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 2 of prior building construction was observed at the surface of the proposed addition area by Soilogic personnel at the time of our site exploration. SITE EXPLORATION Field Exploration To develop subsurface information for the proposed construction, a total of four (4) soil borings were completed. Two (2) of the borings were completed in the area of the proposed addition to a depth of approximately 15 feet below present site grades. Two (2) additional borings were completed in the proposed drive/parking areas to a depth of approximately 10 feet below ground surface. The boring locations were established in the field by Soilogic personnel eased on the provided site plan and by pacing and estimating angles and distances 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. A graphic log of each of the auger borings is also included. The test holes were advanced using 4-inch diameter continuous flight auger powered by a truck -mounted CME-55 drill rig. Samples of the subsurface materials were obtained at regular intervals using California and split -barrel sampling procedures in general accordance with ASTM specification D-1.586. 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. Laboratory Testing The samples collected were tested in the laboratory to measure natural moisture content and visually classified in accordance with the Unified Soil Classification System (USCS). L-1 1 1 I' Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 3 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 completed laboratory testing, a calibrated hand penetrometer (CHP) was used to estimate the unconfined compressive strength of essentially cohesive specimens. The CHP also provides a more reliable estimate of soil consistency than tactual observation alone. Dry density, Atterberg limits, -200 wash and swell/consolidation tests were completed on selected samples to help establish specific soil characteristics. Atterberg limits tests are used to determine soil plasticity. The percent passing the #200 size sieve (-200 wash test) is used to determine the percentage of fine grained soils (clay and silt) in a sample. Swell/consolidation tests are performed to evaluate soil 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 summary sheets. SUBSURFACE CONDITIONS The subsurface materials encountered in the completed site borings can be summarized as follows. Approximately 3 to 6 inches of topsoil and vegetation was encountered at the surface at the boring locations. The topsoil/vegetation was underlain by brown medium stiff to stiff lean clay with varying amounts of silt and sand. The near surface lean clay showed low swell potential at current moisture and density conditions. Softer lean clay soils were encountered with depth in the completed site borings. The lean clay extended to depths ranging from approximately 5 %2 to 6 feet below ground surface and was underlain by brown sand with gravel. The sand and gravel was medium dense to dense and extended to the bottom of boring at depths ranging from approximately 10 to 15 feet below present site grades. 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. At the time of drilling, groundwater was encountered in the completed site borings at a depth of approximately 6 feet below ground surface. Groundwater was measured in open LI Jax Mercantile Improvements Fort Collins; Colorado Soilogic # 09-1025 4 borehole B-2 at a depth of approximately 5.5 feet below ground surface after the completion of drilling. Groundwater levels will vary seasonally and over time based on weather conditions, site development, irrigation practices and other hydrologic conditions. Perched 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. The location and amount of perched water can also vary over time. ANALYSIS AND RECOMMENDATIONS General Groundwater was encountered in the completed site borings at depths ranging from approximately 5%Z to 6 feet below present site grades at the time of drilling. Soft and wet lean clay soils with insufficient strength were encountered with depth in the completed auger borings near current groundwater levels. Careful evaluation of the proposed foundation bearing materials should be completed at the time of construction to help insure the addition footing foundations will bear on like materials with suitable strength. If more extensive zones of soft clay are encountered at that time, some overexcavation/backfill procedures may be required. We understand some excavation procedures may have previously been completed in the proposed addition area. Backfill soils were not easily identifiable in the completed auger borings at the time of drilling. Care should be taken at the time of construction to insure the addition footing foundations, floor slab, exterior flatwork and site pavements will not be supported on or immediately above uncontrolled backf ll soils. Uncontrolled Backfill would need to be removed and replaced as controlled and compacted fill prior to placement to any overlying improvements. The depth and extend of any overexcavation/backfill procedures can best be established at the time of excavation through openhole observation. Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 5 Site Development All existing topsoil and vegetation and previously placed backfill soils should be completely removed from the addition, exterior flatwork and pavement areas. After stripping and completing all cuts and any required removal procedures and. prior placement of any fill, flatwork concrete or site pavements we recommend the exposed subgrade soils be scarified to a depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the material's standard Proctor maximum dry density. The moisture content of the scarified soils should be adjusted to be within the range of ±2% of standard Proctor optimum moisture content at the time of compaction. Fill soils required to develop the site should consist of approved, low volume change soils free from organic matter, debris and other objectionable materials. Based on results of the completed laboratory testing, it is our opinion the site sandy lean clay could be used as fill in structural areas. The site sand and gravel could also be used as fill to develop the site provided those materials are blended with the site lean clay in order to reduce permeability. Fill soils should contain a minimum of 15% fines (material passing the #200 size sieve) in order to reduce the potential of those materials to pond and transmit water. If it is necessary to import material to the site for use as fill, those materials should consist of approved low volume change and relatively impervious materials free from organic matter, debris and other objectionable materials. The site lean clay, clayey sand and gravel or similar materials should be placed in loose lifts not to 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 reconditioned subgrades and site fill soils prior to placement of any overlying improvements. Soils which are allowed to dry out or become wet and softened or disturbed by the construction activities should be removed and replaced or reworked in place prior to concrete placement and/or paving. Foundations Based on the materials encountered in the completed site borings and results of laboratory testing, it is our opinion the proposed lightly loaded addition could be Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 6 supported by continuous spread footing and isolated pad foundations bearing on the near surface medium stiff to stiff lean clay. For design of footing foundations bearing on undisturbed medium stiff lean clay, we recommend using a maximum net allowable soil bearing pressure of 1500 psf. As a precaution, we recommend the footing foundations be designed with a minimum dead load pressure of 500 psf. Careful observation of the proposed foundation bearing materials should be completed at the time of construction to insure all footing foundations will be supported on like materials with suitable strength. 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 passive equivalent fluid pressure value provided does not include an allowance for submerged conditions. A coefficient of friction of 0.35 could be used between foundation 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. For design of light pole bases constructed as drilled concrete shafts, an allowable lateral soil bearing pressure of 100 pcf could be used. 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. Voiding of portions of the footing foundations may be required to develop the minimum recommended dead load pressures with the minimum footing widths outlined above. The soft lean clay encountered with depth would be easily disturbed by the construction activities. Disturbed soils or soils which are allowed to become wetted or dried prior to foundation construction should be removed and replaced or reworked in place prior to concrete placement. 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 within the addition could approach the amount of total settlement estimated above. Some differential movement should be anticipated between the existing Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 7 structure and proposed addition. An allowance for some differential movement should be included in the design. Seismicity Based on our review of the International Building Code (2006), a soil profile type D could be used for the site strata. Based on our review of United States Geologic Survey USES) mapped information, design spectral response acceleration values of SDs = .219 21.9%) and SDI = .093 (9.3%) could be used. Floor Slabs The addition floor slab could be supported directly on reconditioned natural site soils or suitable fill or overexcavation/backfill soils developed as outlined in the "Site Development" portion of this report. Use of a thin sand leveling course could be considered beneath the floor slab to facilitate finish grading. A modulus of subgrade reaction (k) value of 100 pci could be used for design of floor slabs supported on moisture conditioned site lean clay. Careful evaluation of the floor slab subgrades should be completed prior to concrete placement. 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. As a precaution, we recommend all partition walls supported immediately above the addition floor slab be constructed as floating walls to help reduce the potential for differential slab to foundation movement causing distress in upper sections of the addition. Special attention to door framing, drywall and trim carpentry should be taken to 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. Depending on the type of floor covering and floor covering adhesive used in the addition area, a vapor barrier may be required immediately beneath the floor slab. The unilateral moisture release caused by placing concrete on an impermeable surface can increase slab Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 8 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 develop as outlined in the "Site Development" portion of this report. As a precaution, we recommend proof -rolling of the pavement subgrades be completed to help identify areas of instability. Unstable areas would need to be mended prior to paving. Care should be taken to avoid disturbing the reconditioned subgrades and placed fill or overexcavahon/backfill soils prior to placement of site pavements and exterior flatwork. In addition, efforts to maintain the proper moisture content in the subgrade soils shouldRbemade. If subgrade soils are disturbed by the construction activities 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. Site Pavements Site pavements could be supported directly on the suitable subgrade soils developed as outlined above. The site lean clay would be subject to low remolded shear strength. A resistance value (R-value) of 5 was estimated for the lean clay subgrade soils and used in the pavement section design. Traffic loading on site pavements is expected to consist of areas of both low volumes of automobiles and light trucks as well as areas of higher light vehicle traffic volumes and 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 classifications are outlined below in Table I. Standard duty pavements could be considered in automobile drive and parking areas. Heavy duty Jax.Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 9 pavements should be considered for access drives and other areas of the site expected to receive higher traffic volumes or heavy delivery or trash truck traffic. Depending on the time of year when construction occurs, 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. Pavement section design options incorporating structural credit for stabilized subgrade soils are outlined below. Fly ash stabilization can eliminate some of the uncertainty associated with attempting to pave during periods of inclement weather. TABLE I — ON SITE PAVEMENT SECTION DESIGN _ Standard Duty Heavy Du Option A -Composite Asphaltic Concrete (Grading S or SX) 4" 5" Aggre ate Base Class 5 or 6 6;, g„ Option B — Composite on Stabilized Subgrade Asphaltic Concrete (Grading S or SX) 3" 4" Aggregate Base (Class 5 or 6) 4" 6" Fly Ash Stabilized Sub de 12" 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 mix should meet specific gradation requirements such as Colorado Department of Transportation (CDOT) grading S (3/4 inch minus) or SX (1/2 inch minus) specifications. Hot mix asphalt designed using Superpave" criteria should be compacted to within 92% to 96% at the material's maximum theoretical density (Rice value). Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 10 Aggregate base should be consistent with CDOT requirements for Class 5 or Class 6 base, 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 13% class C fly ash based on component dry unit weights. A 12-inch thick stabilized zone should be constructed by thoroughly blending the fly ash with the in -place subgrade soils. Some "fluffing" of the finish subgrade level should be expected with the stabilization procedures. The blended materials should be adjusted to within f2% 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 the addition of fly ash. 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 a Portland. cement concrete pavement with a minimum thickness of 6 inches. The concrete used for site pavements should be air entrained and have a minimum 28-day compressive strength of 4,000 psi. Woven wire mesh or fiber entrained concrete should be considered to help in the control of shrinkage cracking. The proposed pavement section designs do not include an allowance for excessive loading conditions imposed by heavy construction vehicles or equipment. Heavily loaded concrete or other building material trucks and construction equipment can cause some localized distress to site pavements. The recommended pavement sections are minimums and periodic maintenance efforts should be expected. A preventative maintenance program can help increase the service life of site pavements. North College Avenue and Jerome At this time we understand widening of North College Avenue and construction of a portion of Jerome may be completed as part of the proposed off -site improvements. Additional subsurface exploration and a final pavement section design would be required after development of approximate finish subgrade levels for the roadways. In newly constructed roadway areas (Jerome) City of Fort Collins guidelines require that sanitary Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 11 sewer be installed and the roadway developed to approximate finish subgrade level prior to drilling. Preliminary pavement section design estimates are outlined below in Table II based on discussions with City of Fort Collins personnel. The pavement sections outlined for North College Avenue are based on a final pavement section design completed for the City of Fort Collins. The pavement sections outlined for Jerome are based on traffic loading provided by the City of Fort Collins. TABLE II — PAVEMENT SECTION DESIGN ESTIMATES _relmin. _ Onl North College Jerome Avenue Option A — Match Existing Asphaltic Concrete (Grading S) 3 ``/z" Portland Cement Concrete Pavement 8" Aggregate Base (Class 5 or 6) 6" Swell Mitigation Zone Option B — Composite Asphaltic Concrete (Grading S) 8" 5'/z" Aggregate Base (Class 5 or 6) 8'/z" 11" Option C - Portland Cement Concrete Pavement Portland Cement Concrete Pavement 11" 6`/<" Aggregate Base (Class 5 or 6) 6" The City of Fort Collins anticipates swell mitigation procedures will be required for the referenced portion of North College Avenue. Approximately 2 to 3 feet of overexcavation/backfill procedures or twelve (12) inches of fly ash treatment could be considered for preliminary estimates. Expansive soils were not encountered in the area of boring B-1 completed adjacent to Jerome such that we do not expect swell mitigation procedures would be required to develop low volume change potential subgrade soils in this area. Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 12 Retaining Wall Design and Construction At this time we understand retaining walls may be constructed in order to develop a detention pond area for this site. The exact location of the detention pond was not known at the time of drilling such that site specific borings were not completed in the retaining wall area. Careful observation of the retaining wall foundation bearing materials should be completed at the time of construction to insure the retaining wall will be supported on materials with suitable strength. If soft clay soils are encountered at foundation bearing level, some overexcavation/backfill procedures may be required. For design of retaining wall footing foundations bearing on natural undisturbed medium stiff lean clay or medium dense sand and gravel, we recommend using a maximum net allowable soil bearing pressure of 1,500 psf. Care will be needed to avoid disturbing retaining wall foundation bearing materials prior to concrete placement. Foundation bearing materials disturbed by the construction activities should be removed and replaced or reworked in place prior to foundation construction. Retaining wall footing foundations should bear a minimum of 30 inches below shallowest adjacent grade to provide frost protection. Depending on the depth of the detention pond, some dewatering of the retaining wall foundation excavations may be required during construction. We recommend weep holes or other appropriate drainage systems be installed on the retained soil side of the wall to reduce the potential for development of unbalanced hydrostatic loads. Retaining wall backfill should consist of approved low volume change and essentially granular materials free from organic matter and debris. Materials consistent with Colorado Department of Transportation (CDOT) class 7 specifications could be used as retaining wall backfill. The site sand and gravel could also be considered for use as retaining wall backfill. Retaining wall backfill should 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. The moisture content of the backfill Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 13 soils should be adjusted to within f2% of standard Proctor optimum moisture content at the time of compaction. Excessive lateral stresses can be imposed on retaining walls during backfilling when using heavier mechanical compaction equipment. We recommend compaction of retaining wall backfill be completed using light mechanical or hand compaction equipment. For design of retaining walls protected from hydrostatic loading and backfilled with select granular fill, we recommend using an angle of internal friction of 0=30' and active equivalent fluid pressure value of 40 pounds per cubic foot in addition to any surcharge loads. The equivalent fluid pressure value outlined above is based on an active stress distribution analysis in which some rotation of the retaining wall is assumed. Lateral movement of retaining walls would be resisted by passive earth pressures and frictional resistance between the retaining wall foundation and bearing soils. A passive equivalent fluid pressure value of 250 pcf could be used for that portion of the wall extending below grade and above seasonal high groundwater. A passive equivalent fluid pressure value of 120 pcf could be used for submerged conditions. A coefficient of friction of 0.35 could be used for sliding resistance between foundation concrete and bearing soils. The equivalent fluid pressure values, angle of internal friction and coefficient of friction parameters outlined above do not include a factor of safety. Surcharge loads on the retained soil side of the walls or point loads developed in the wall backfill can add to the lateral forces on retaining walls. If parking areas will be constructed at the top of the retained soil side of the wall, surcharge loads from vehicles should be included in the design. Drainage Positive drainage is imperative for long term performance of the proposed addition and associated site improvements. We recommend positive drainage be developed away from the addition with twelve (12) inches of fall in the first 10 feet away from the addition during construction and throughout the life of the site improvements. Shallower slopes could be considered in hardscape areas. In the event that some settlement of the Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 14 addition 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 proposed addition 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 addition 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. Jax Mercantile Improvements Fort Collins, Colorado Soilogic # 09-1025 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. 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