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Home My WebLink AboutHOME INSTEAD PLAZA - Filed GR-GEOTECHNICAL REPORT/SOILS REPORT -41 GEOTECHNICAL EXPLORATION REPORT PROPOSED TWO-STORY OFFICE BUILDING JFK PARKWAY AND EAST BOARDWALK DRIVE FORT COLLINS, COLORADO EEC PROJECT NO. 1132068 Prepared for: Doberstein Lemburg Commercial, Inc. 1401 Riverside Avenue Fort Collins, Colorado 80524 Attn: Mr. Dan Bernth(danbernth@frii.com) Prepared by: Earth Engineering Consultants, LLC 4396 Greenfield Drive Windsor, Colorado 80550 EEC EE C EARTH ENGINEERING CONSULTANTS,LLC September 27, 2013 Doberstein Lemburg Commercial, Inc. 1401 Riverside Avenue Fort Collins, Colorado 80524 Attn: Mr. Dan Bernth(danbernth@frii.com) Re: Geotechnical Exploration Report Proposed Two-Story Office Building JFK Parkway and East Boardwalk Drive Fort Collins, Colorado EEC Project No. 1132068 Mr. Bernth: Enclosed, herewith, are the results of the geotechnical subsurface exploration completed by Earth Engineering Consultants, LLC (EEC) personnel for the referenced project. In general, this project involves construction of a two-story office building on a vacant parcel located at the southeast corner of JFK Parkway and East Boardwalk Drive in Fort Collins. To develop subsurface information for the proposed office building and associated site improvements, EEC personnel advanced five (5) soil borings on the site extending to depths of approximately 10 to 30 feet below present site grades. This exploration was completed in general accordance with our proposal dated August 20, 2013. In summary, subsurface conditions observed at the boring locations included mixed fill materials to depths of approximately 2 to 5 feet below existing site grades underlain by a thin sandy lean clay zones in two of the borings and by highly weathered to weathered sandstone/siltstone/claystone bedrock. The siltstone/sandstone/claystone bedrock extended to the bottom of the borings at depths of approximately 10 to 30 feet below present site grades. Free groundwater was not observed in the test borings at the time of completion. 4396 GREENFIELD DRIVE WINDSOR, COLORADO 80550 970) 545-3908 FAX (970) 663-0282 www.earth-enaineering.com Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 2 Based on materials observed at the boring locations, we believe the lightly to moderately loaded office building could be supported on conventional footing foundations extending to bear on the highly to weathered sandstone/siltstone/claystone bedrock. The overlying fill soils were of mixed composition, consistency and swell potential. As such, we recommend those materials be removed and replaced as controlled fills to develop support for floor slabs, pavements and site flatwork. Care will be needed at the time of construction to further evaluate/monitor the fill materials for reuse in the building floor slabs and site pavement/flatwork subgrades. Geotechnical recommendations concerning design and construction of the foundations and support of floor slabs, pavements and flatwork are provided in the attached report. If you have any questions concerning this report, or if we can be of further service to you in any other way,please do not hesitate to contact us. Very truly yours, Earth Engineering Consultants, LLC 70cial) Lester L. Litton, P.E. Principal Engineer Reviewed by: Ethan P. Wiechert, P.E. Senior Project Engineer GEOTECHNICAL EXPLORATION REPORT PROPOSED TWO-STORY OFFICE BUILDING JFK PARKWAY AND EAST BOARDWALK DRIVE FORT COLLINS, COLORADO EEC PROJECT NO. 1132068 September 27, 2013 INTRODUCTION The geotechnical subsurface exploration for the proposed two-story office building at the southeast corner of JFK Parkway and East Boardwalk Drive in Fort Collins,Colorado,has been completed. Two(2)soil borings extended to depths of approximately 15 to 30 feet below present site grades were advanced within the proposal building area to develop information on existing subsurface conditions. One(1)additional boring extending to a depth of approximately 15 feet was advanced in the area of a possible drive thru coffee kiosk and two (2)borings to depths of approximately 10 feet were completed in site drive and parking areas. Individual boring logs and diagram indicating the approximate boring locations are included with this report. We understand this project involves the construction of a two-story, slab-on-grade (non- basement)office building at the approximate location indicated on the attached boring location diagram. We expect foundation loads for that structure will be light with continuous wall loads less than 4 kips per lineal foot and individual column loads less than 100 kips. Floor loads are also expected to be light. Paved drive and parking areas will be constructed as a part of the site improvements. A small drive thru coffee kiosk is planned for the site; that building will be designed and constructed by others. We anticipate small grade changes from existing grades will be required to develop the finish site grades for the proposed construction. The purpose of this report is to describe the subsurface conditions encountered in the test borings, analyze and evaluate developed data on site subsurface conditions and provide geotechnical recommendations concerning design and construction of the foundations and support of floor slabs,pavements and flatwork. EXPLORATION AND TESTING PROCEDURES The test boring locations were selected and established in the field by Earth Engineering Consultants, LLC (EEC) personnel by pacing and estimating angles from identifiable site features. The approximate boring locations are indicated on the attached boring location diagram. Those locations should be considered accurate only to the degree implied by the methods used to make the field measurements. Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 2 The field borings were completed using a truck-mounted, CME-55 drill rig equipped with a hydraulic head employed in drilling and sampling operations. The boreholes were advanced using 4-inch nominal diameter continuous flight augers and samples of the subsurface materials encountered were obtained using split barrel and California barrel sampling procedures in general accordance with ASTM Specifications D1586 and D3550. In the split barrel and California barrel sampling procedures,standard sampling spoons are driven into the ground by means of a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the split barrel and California barrel samplers is recorded and is used to estimate the in-situ relative density of cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils and hardness of weathered bedrock. All samples obtained in the field were sealed and returned to our laboratory for further examination, classification, and testing. In the California barrel sampling procedure,relatively undisturbed samples are obtained in brass sampling sleeves. Moisture content tests were completed on each of the recovered samples along with dry density determination of appropriate California barrel samples. The unconfined strength of appropriate samples was estimated using a calibrated hand penetrometer. Washed sieve analysis and Atterberg limits tests were completed on selected samples to determine the quantity and plasticity of the fines in the subgrade materials. Swell/consolidation tests were also completed on select samples to evaluate the soil and bedrock tendency to change volume with variation in moisture content and load. Soluble sulfate tests were completed to evaluate possible sulfate attack on site cast concrete. Results of the outlined tests are indicated on the attached boring logs and summary sheets. As part of the testing program, all samples were examined in the laboratory and classified in accordance with the attached General Notes and the Unified Soil Classification System,based on the soil's texture and plasticity. The estimated group symbol for the Unified Soil Classification System is indicated on the boring logs and a brief description of that classification system is included with this report. Classification of the bedrock was based on visual and tactual observation of disturbed samples and auger cuttings. Coring and/or petrographic analysis may reveal other rock types. Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 3 SITE AND SUBSURFACE CONDITIONS The proposed development site is located on a triangular parcel of land at the southeast corner of JFK Parkway and East Boardwalk Drive in Fort Collins. A post office is located to the south and east of this building site with the post office drive areas running parallel to the site drives. Apparent cuts have been completed on the site to lower site grades below the grade of adjacent JFK Parkway and Boardwalk Drive. At present, the site is relatively flat with slight surface drainage to the east. Based on results of the field borings and laboratory testing, subsurface conditions can be generalized as follows. Sparse vegetation was observed at the ground surface at the boring locations. In the building areas, the vegetation was underlain by fill and apparent fill soils consisting of sandy lean clay in borings B-1 and B-3 and mixed sandstone/siltstone bedrock in boring B-2. The fill materials extended to depths ranging from approximately 2 feet in boring B- 2 to 5 feet in boring B-1. In boring B-3, the apparent fill soils were underlain by clayey sand, sandy lean clay to depths of approximately 9'h feet. The cohesive soils were stiff to very stiff and relatively dry. The sandy lean clay in boring B-3 and the fill soils in borings B-1 and B-2 were underlain by siltstone/sandstone bedrock. Some claystone layering was observed in boring B-3. The bedrock materials were generally moderately hard with low swell potential. Those materials extended to the bottom of the borings at depths of approximately 15 to 30 feet. Similar subgrade materials were observed in the pavement related borings,borings B-4 and B-5. Apparent fill material extended to a depth of approximately 4 feet in boring B-4;no apparent fill was encountered in boring B-5. Silty sandy lean clay extended to a depth of approximately 2'/2 feet in boring B-5 and from the bottom of the fill to a depth of approximately 51/2 feet in boring B- 4. Sandstone/siltstone/claystone bedrock was observed beneath the lean clay soils and extended to the bottom of both borings at depths of approximately 10 feet. The stratification boundaries indicated on the boring logs represent the approximate locations of changes in soil and rock types;in-situ,the transition of materials may be gradual and indistinct. GROUNDWATER CONDITIONS Observations were made while drilling and after completion of the borings,to detect the presence and depth to the hydrostatic groundwater table. Free water was not observed in any of the test Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 4 borings at the time of drilling. The boreholes were backfilled upon completion of drilling and additional groundwater measurements were not obtained. Fluctuations in groundwater levels can occur over time depending on variations in hydrologic conditions, and other conditions not apparent at the time of this report. In addition, zones of perched and/or trapped water can be encountered in more permeable zones in the subgrade soils or in fractured or highly permeability zones interbedded within the bedrock. Perched water is commonly encountered in soils immediately above a low permeability bedrock layer. The location and amount of perched/trapped water can also vary over time dependent on variations in hydrologic conditions and other conditions not apparent at the time of this report. ANALYSIS AND RECOMMENDATIONS Swell—Consolidation Test Results The swell-consolidation test is performed to evaluate the swell or collapse potential of soils to help in determining foundation, floor slab and/or pavement design criteria. In this test, relatively undisturbed samples obtained directly from the California barrel sampler are placed in a laboratory apparatus and inundated with water under a predetermined load. The swell-index is the resulting amount of swell or collapse after the inundation period expressed as a percent of the sample's preload/initial thickness. After the inundation period, additional incremental loads are applied to evaluate the swell pressure and/or consolidation. For this assessment,we conducted six(6) swell-consolidation tests on relatively undisturbed soil samples obtained at various intervals/depths. Based on the laboratory test results, the in-situ samples analyzed for this project showed moderate swell for the dryer,higher density apparent fill soils and little to no swell for higher moisture, lower density materials. Site Preparation Preliminary grading plans were not provided to us prior to preparation of this subsurface exploration report. However,based on observed site conditions,it appears that small cuts or fills will be needed to achieve final site grades. Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 5 All existing vegetation and/or topsoil should be removed from within the building and pavement foot prints or within site fill areas. In addition,close evaluation of the in-place materials will be required at the time of construction to monitor for unacceptable in-place fill materials, construction debris, and/or suitability of the in-place materials for reuse as engineered fill. Unacceptable materials, soft/loose fill materials, and/or the in-situ near surface dry and dense apparent fill soils should be removed from the building,pavement and flatwork areas. Based on the results of the test borings, we expect the in-place fill materials will need to be removed/reworked to depths of 2 to 4 feet depending on site location. After removal of all topsoil/vegetation or any other unacceptable materials within the planned development areas, including the in-place fill materials, and prior to fill placement and/or site improvements, the exposed subgrades should be scarified to a minimum depth of 9-inches, adjusted in moisture content to within+/-2%of standard Proctor optimum moisture content and compacted to at least 95%of the material's standard Proctor maximum dry density as determined in accordance with ASTM Specification D698. Fill soils required for developing the building subgrades, including areas overexcavated to remove unacceptable in-place fill materials, should consist of approved, low-volume-change materials, which are free from organic matter and debris. Based on the testing completed, it appears the on-site lean clay apparent fill and native soils could be used as general site fill provided adequate moisture treatment and compaction procedures are followed. Claystone bedrock materials should not be used for fill below site improvement areas. Import materials similar to the site lean clay or consisting of granular structural fill with sufficient fines to prevent ponding of water in the fill materials could be used. The site fill materials should be placed in loose lifts not to exceed 9 inches thick,adjusted in moisture content to±2%of optimum moisture content and compacted to at least 95% of the materials maximum dry density as determined in accordance with ASTM Specification D698,the standard Proctor procedure. Care will be needed after preparation of the subgrades to avoid disturbing the subgrade materials. Positive drainage should be developed away from site structures to avoid wetting of subgrade materials. Subgrade materials becoming wet subsequent to construction of the site improvements could result in unacceptable performance. Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 6 Office Building Foundations Based on the results of our field borings and laboratory testing as outlined in this report,it is our opinion the proposed two-story, lightly loaded office building could be supported on conventional footing foundations bearing on the moderately hard weathered sandstone/siltstone bedrock. For design of footing foundations bearing on the native bedrock materials, we recommend using a net allowable total load soil bearing pressure not to exceed 4,000 psf. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. The foundations should all bear on the underlying bedrock to reduce the potential for differential movement of dissimilar bearing materials. Close evaluation of the foundation bearing strata will be necessary during the construction phase. Exterior foundations and foundations in unheated areas should be located a minimum of 30 inches below adjacent exterior grade to provide frost protection. We recommend formed continuous footings have a minimum width of 12 inches and isolated column foundations have a minimum width of 24 inches. Trenched and/or grade beam foundations should not be used in the near surface soils to allow for close observation of the bearing strata. Care should be taken during construction to see that the footing foundations as well as all floor slabs are supported on suitable strength subsoils and/or approved engineered fill materials. In areas of the site where former fill/backfill soils were placed,unacceptable materials will likely be encountered. Extra care should be taken in evaluating the in-place soils in these areas as the fill/backfill materials do not generally appear acceptable for future support of floor slabs and/or pavements. No unusual problems are anticipated in completing the excavations required for construction of the footing foundations. Care should be taken during construction to avoid disturbing the foundation bearing materials. Materials which are loosened or disturbed by the construction activities or materials which become dry and desiccated or wet and softened should be removed and replaced prior to placement of foundation concrete. We anticipate settlement of the footing foundations designed and constructed as outlined above would be less than 1 inch. Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 7 Coffee Shop Foundations A small drive through coffee shop will be located east of the new office. The foundation loads for the drive through building are expected to be very light. Subgrade soils in this area included approximately 3 feet of in-place fill soils over natural sandy lean clays. We believe the very lightly loaded coffee shop could likely be supported on conventional footings supported on the natural sandy lean clays. Support of the building area post-tension slab-on-grade foundation could also be considered. Specific recommendations for support of this building can be provided after more specific information concerning this structure is available. Floor Slab Design and Construction All existing vegetation and/or topsoil should be removed from beneath the new floor slabs. Soft or loose in-place fill/backfill,any wet and softened or dry and desiccated soils encountered within the proposed building areas or any unacceptable in-place fill soils should be removed from the floor areas. After stripping, completing all cuts and removal of any unacceptable materials and prior to placement of any new fill or floor slabs, the in-place soils should be scarified to a minimum depth of 9 inches, adjusted in moisture content and compacted to at least 95% of maximum dry density as determined in accordance with ASTM Specification D698,the standard Proctor procedure. The moisture content of the scarified materials should be adjusted to be within the range of±2% of standard Proctor optimum moisture at the time of compaction. Fill materials required to develop the floor slab subgrades should consist of approved, low-. volume change materials which are free from organic matter and debris. We recommend the fill materials contain sufficient fines to prevent ponding of water in the subgrade subsequent to construction. The on-site sandy clay/clayey sand materials are acceptable for use as fill in the floor slab subgrade areas; the claystone bedrock should not be used for fill. Fill materials beneath the floor slabs should be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content as recommended for the scarified materials and compacted to at least 95% of the material's standard Proctor maximum dry density. Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 8 After preparation of the subgrades, care should be taken to avoid disturbing the subgrade materials. Materials which are loosened or disturbed by the construction activities will require removal and replacement or reworking in place prior to placement of the overlying floor slabs. Positive drainage should be developed away from the proposed building to avoid wetting the subgrade or bearing materials. Subgrade or bearing materials allowed to become wetted subsequent to construction could result in unacceptable performance of the improvements. Pavements We expect the site pavements will include areas designated for low volume automobile traffic/parking and areas of heavier/higher volume traffic. For heavier traffic areas,we are using an assumed equivalent daily load axle(EDLA)rating of 15 and in automobile/parking areas we are using an EDLA of 5. Proofrolling and recompacting the subgrade is recommended immediately prior to placement of the pavements. Soft or weak areas delineated by the proofrolling operations should be undercut or stabilized in-place to achieve the appropriate subgrade support. Based on the subsurface conditions encountered at the site and the results of the laboratory testing,it is recommended the on-site private drives and parking areas be designed using an R-value of 5. Due to the moderately expansive characteristics of the overburden site fill soils,a swell mitigation plan will be necessary to reduce the potential for movement within the pavement section. As presented in the"Site Preparation"section of this report,we recommended overexcavating the in- place fill soils and the replacement of these soils as moisture conditioned/engineered fill material beneath pavement areas. Pumping conditions could develop within a moisture treatment process of on-site cohesive soils. Subgrade stabilization may be needed to develop a stable subgrade for paving. If needed,stabilization could include incorporating at least 12 percent(by weight)Class C fly ash into the upper 12 inches of subgrade. Eliminating the risk of movement within the proposed pavement section may not be feasible due to the characteristics of the subsurface materials; but it may be possible to further reduce the risk of movement if more extensive subgrade stabilization measures are used during construction. We would be pleased to discuss other construction alternatives with you upon request. Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 9 Pavement design methods are intended to provide structural sections with adequate thickness over a particular subgrade such that wheel loads are reduced to a level the subgrade can support. The support characteristics of the subgrade for pavement design do not account for shrink/swell movements of an expansive clay subgrade or consolidation of a wetted subgrade. Thus, the pavement may be adequate from a structural standpoint, yet still experience cracking and deformation due to shrink/swell related movement of the subgrade. It is,therefore,important to minimize moisture changes in the subgrade to reduce shrink/swell movements. Recommended pavement sections are provided below in Table 1. If selected, Portland cement concrete should be an exterior pavement design mix with a minimum 28-day compressive strength of 4,000 psi and should be air entrained. Hot bituminous pavement should consist of S- 75 or SX-75 with performance graded PG 58-28 or 64-22 binder, compacted to be within the range of 92 to 96% of maximum theoretical specific gravity (Rice). In the drive lanes for the coffee kiosk and/or areas subject to heavier truck loads or truck turning movements, (including trash truck routes and load/unload areas)consideration should be given to use of Portland cement concrete for the pavements. The recommended pavement sections are minimums and periodic maintenance should be expected. Table 1. Recommended Minimum Pavement Sections Automobile Parking Heavy Duty Areas 18-kip EDLA 5 15 18-kip ESAL's 36,500 109,500 Reliability 75% 85% Resilient Modulus 3025 psi 3025 psi PSI Loss 2.5 2.0 Design Structure Number 2.47 3.09 A)Composite Hot Bituminous Pavement 4" 5" Aggregate Base 6" 8" Design Structural Number) 2.42) 3.08) B)Composite with Fly Ash Treated Subgrade Hot Bituminous Pavement 3" 4" Aggregate Base 6" 7" Fly Ash Treated Subgrade 12" 12" Design Structure Number) 2.58) 3.13) C)PCC(Non-reinforced) 5" 6" Longitudinal and transverse joints should be provided as needed in concrete pavements for expansion/contraction and isolation. The location and extent of joints should be based upon the final pavement geometry. Sawed joints should be cut in accordance with ACPA or ACI recommendations. All joints should be sealed to prevent entry of foreign material and dowelled or tied where necessary and appropriate for load transfer. Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 10 Since the cohesive soils on the site have some shrink/swell potential,pavements could crack in the future primarily because of the volume change of the soils when subjected to an increase in moisture content to the subgrade. The cracking,while not desirable,does not necessarily constitute structural failure of the pavement. The collection and diversion of surface drainage away from paved areas is critical to the satisfactory performance of the pavement. Drainage design should provide for the removal of water from paved areas in order to reduce the potential for wetting of the subgrade soils. Long-term pavement performance will be dependent upon several factors,including maintaining subgrade moisture levels and providing for preventive maintenance. The following recommendations should be considered the minimum: The subgrade and the pavement surface should be adequately sloped to promote proper surface drainage. Install pavement drainage surrounding areas anticipated for frequent wetting (e.g. garden centers, landscaped islands) Install joint sealant and seal cracks immediately. Seal all landscaped areas in, or adjacent to pavements to minimize or prevent moisture migration to subgrade soils. Place compacted, low permeability backfill against the exterior side of curb and gutter; and place curb, gutter, and/or sidewalk directly on approved proof rolled subgrade soils. Preventive maintenance should be planned and provided for an on-going pavement management program. Preventive maintenance activities are intended to slow the rate of pavement deterioration and to preserve the pavement investment. Preventive maintenance consists of both localized maintenance (e.g. crack and joint sealing and patching) and global maintenance (e.g. surface sealing). Preventive maintenance is usually the first priority when implementing a planned pavement maintenance program and provides the highest return on investment for pavements. Prior to implementing any maintenance,additional engineering observation is recommended to determine the type and extent of preventive maintenance. Site grading is generally accomplished early in the construction phase. However as construction proceeds,the subgrade may be disturbed due to utility excavations,construction traffic,desiccation, Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 11 or rainfall. As a result,the pavement subgrade may not be suitable for pavement construction and corrective action will be required. The subgrade should be carefully evaluated at the time of pavement construction for signs of disturbance, such as but not limited to drying, or excessive rutting. If disturbance has occurred, pavement subgrade areas should be reworked, moisture conditioned, and properly compacted to the recommendations in this report immediately prior to paving. Note that if during or after placement of the stabilization or initial lift of pavement, the area is observed to be yielding under vehicle traffic or construction equipment, it is recommended that EEC be contacted for additional alternative methods of stabilization,or a change in the pavement section. Other Considerations Positive drainage should be developed away from the structure and pavement areas with a minimum slope of 1 inch per foot for the first 10 feet away from the improvements in landscape areas. Care should be taken in planning of landscaping adjacent to the building and parking and drive areas to avoid features which would pond water adjacent to the pavement, foundations or stemwalls. Placement of plants which require irrigation systems or could result in fluctuations of the moisture content of the subgrade material should be avoided adjacent to site improvements. Lawn watering systems should not be placed within 5 feet of the perimeter of the building and parking areas. Spray heads should be designed not to spray water on or immediately adjacent to the structure or site pavements. Roof drains should be designed to discharge at least 5 feet away from the structure and away from the pavement areas. Excavations into the on-site lean clay subsoils should be relatively stable for short term construction activities depending, in part, upon the depth of excavation and excavation side slopes. The individual contractor(s)should be made responsible for designing and constructing stable,temporary excavations as required to maintain stability of both the excavation sides and bottom. All excavations should be sloped or shored following local and federal regulations, including current OSHA excavation and trench safety standards. Earth Engineering Consultants,LLC EEC Project No. 1132068 September 27,2013 Page 12 GENERAL COMMENTS The analysis and recommendations presented in this report are based upon the data obtained from the soil borings performed at the indicated locations and from any other information discussed in this report. This report does not reflect any variations, which may occur between borings or across the site. The nature and extent of such variations may not become evident until construction. If variations appear evident, it will be necessary to re-evaluate the recommendations of this report. It is recommended that the geotechnical engineer be retained to review the plans and specifications so comments can be made regarding the interpretation and implementation of our geotechnical recommendations in the design and specifications. It is further recommended that the geotechnical engineer be retained for testing and observations during earthwork and foundation construction phases to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of Doberstein Lemburg Commercial,Inc.for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranty, express or implied, is made. In the event that any changes in the nature, design, or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the conclusions of this report are modified or verified in writing by the geotechnical engineer. DRILLING AND EXPLORATION DRILLING&SAMPLING SYMBOLS: SS: Split Spoon- 13/8"I.D.,2"O.D.,unless otherwise noted PS: Piston Sample ST: Thin-Walled Tube-2"O.D.,unless otherwise noted WS: Wash Sample R: Ring Barrel Sampler-2.42"I.D.,3"O.D.unless otherwise noted PA: Power Auger FT: Fish Tail Bit HA: Hand Auger RB: Rock Bit DB: Diamond Bit=4",N,B BS: Bulk Sample AS: Auger Sample PM: Pressure Meter HS: Hollow Stem Auger WB: Wash Bore Standard"N"Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2-inch O.D.split spoon,except where noted. 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 Casting Removal Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils,the indicated levels may reflect the location of ground water. In low permeability soils,the accurate determination of ground water levels is not possible with only short term observations. DESCRIPTIVE SOIL CLASSIFICATION DEGREE OF WEATHERING: Soil Classification is based on the Unified Soil Classification Slight Slight decomposition of parent material on system and the ASTM Designations D-2488. Coarse Grained joints. May be color change. Soils have move than 50%of their dry weight retained on a#200 Moderate Some decomposition and color change sieve;they are described as: boulders,cobbles,gravel or sand.throughout. Fine Grained Soils have less than 50% of their dry weight High Rock highly decomposed,may be extremely retained on a#200 sieve;they are described as: clays, if they broken. are plastic, and silts if they are slightly plastic or non-plastic. HARDNESS AND DEGREE OF CEMENTATION: Major constituents may be added as modifiers and minor Limestone and Dolomite: constituents may be added according to the relative proportions Hard Difficult to scratch with knife. based on grain size. In addition to gradation, coarse grained Moderately Can be scratched easily with knife. soils are defined on the basis of their relative in-place density and fine grained soils on the basis of their consistency. Hard Cannot be scratched with fingernail. Example: Lean clay with sand, trace gravel, stiff(CL); silty Soft Can be scratched with fingernail. sand,trace gravel,medium dense(SM). Shale,Siltstone and Claystone: CONSISTENCY OF FINE-GRAINED SOILS Hard Can be scratched easily with knife,cannot be scratched with fingernail. Unconfined Compressive Moderately Can be scratched with fingernail. Strength,Qu,psf Consistency Hard Soft Can be easily dented but not molded with 500 Very Soft fingers. 500- 1,000 Soft Sandstone and Conglomerate: 1,001 - 2,000 Medium Well Capable of scratching a knife blade. 2,001 - 4,000 Stiff Cemented 4,001 - 8,000 Very Stiff Cemented Can be scratched with knife. 8,001 - 16,000 Very Hard Poorly Can be broken apart easily with fingers. RELATIVE DENSITY OF COARSE-GRAINED SOILS: Cemented N-Blows/ft Relative Density 0-3 Very Loose 4-9 Loose 10-29 Medium Dense E Ec30-49 Dense 50-80 Very Dense 80+ Extremely Dense PHYSICAL PROPERTIES OF BEDROCK UN.LIHI ED SOUL CLAS S iF1CA'flON SYSTEM Soil Classification Group Group Name Criteria for Assigning Group Symbols and Group names Using Laboratory Tests Symbol Coarse-Grained Grovels more than Clean Grovels Less Soils more than 50% of coarse than 5% fines Cu>4 and <Qc<3E GW Well-graded grovel` 50% retained on fraction retained Na. 200 sieve on No. 4 sieve Cu<4 and/or 1>Cc>3E GP Poorly-graded grovel` Gravels with Fines Fines classify as ML or MH GM Silty gravel, G,H more than 12% fines Fines classify as CL or CH GC Clayey Gravel`'`'° Sands 50% or Clean Sands Less Cu>_5 and 1«c<3E sw Well-graded sand' more coarse than 5% fines fraction passes Cu<5 and/or 1>Cc>3E SP Poorly-graded sand' No. 4 sieve Sands with Fines Fines classify as ML or MH SM Silty sand°''a more than 12% fines Fines classify as CL or CH SC Clayey sandy'" Fine-Grained Silts and Clays inorganic PI>7 and plots on or above 'A"Line' CL Lean cloy' Soils 50% or Liquid Limit less more posses the than 50 PI<4 or plots below °A"Line ML Silt" No. 200 sieve organic Liquid Limit - oven dried Organic cloy 1 0.75 OL Liquid Limit - not dried Organic silt' Silts and Clays inorganic PI plots on or above "Aline CH Fat cloy e'-" Liquid Limit 50 or more PI plots below "A'Line MH Elastic Sit organic Liquid Limit - oven dried Organic cloy"' 0.75 OH Liquid Limit - not dried Organic silt° ° 1 Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat Abased on the moteriol passing the 3-in. (75- 1: IJn)ell sot contains 15 to 29%plus No. 200. add mot) sieve Cu=0sn/01 Cc= x with sond' or 'with grave!", whichever is If Field sample contained cobbles or boulders. predominanL or both, odd with cobbles or boulders, or bath' tIf sal contoins 2 30" plus Na. 200 to group name. r predominantly sand. odd 'sandy to group Grovels with 5 to 12% fines required dual 1f sail contoins 215% sonC, odd"withsond'to name. symbols-. group name. It sot contoins 2 30% plus Na. 200 GW-GM wellgraded gravel with silt If fines claSsify gs CL-ML, use dual symbol predominantly grovel, "gravely'GC-CM, or ssify o redominontl odd ravel ' to group GW-GC well-graded grovel with cloy name. If Fines ore organic, add"with organic fines'lo GP-GM poorly-graded grovel with silt P124 and plots an or above "A" line. group norne CP-GC poorly-graded grovel with day If sot contains >15 ravel, add"with rove(' 1pl or plots below "A' line. Sonds with 5 to 12% fines require dual 9 PI plots on or above 'A' line. nam symbols: aI1 Artterberg oup Gaits plots shooed area, sot is a PI plots below 'A line. SW-SM well-graded sand with silt CL-ML, cilty cloy.SW-SC well-graded sand with cloy SP-SM poorly graded sand with slit i SP-5C poorly graded sand with cloy 60 nor Classification of Mrgrolned soils I/ and rna-grained traction of morse- grei,ed soil. e 50 Equation of'A'-fine Hurimnld of P1-4 to LL+25.5, r men PI-573(LL-20) tiri e dEquation of v"-line Z. 40_ Vertical of LL-I6 to PI"7, F X then Pl..0.9(LL-6) Jr/' Z G 30 I- t 5 Oin20- z, MH as OHJir\v0_ 10- e' f/.i iri' ML IR OL 0 0 i0 20 30 '0 50 60 70 60 90 100 110 LIQUID LIMIT (LL) JJ O o N 12-2 m o Z fa N .0 I 7 0. Q a a M CL O y0 Z v ao CD r ° ir 4 r\-J Q J V1 O Z Wi ;le W Ztill3 W K7 e . ' w il O O t. \ ,, kt 01 I lOg rvit i t it,Th u CO 5u A tTri 1: g/i-vautssvi IA 1 IliMAMPAi,„, R,i.., . ,. 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' 44% -,k- 1, I t' • A.. ti 0 141tiAA VAt Mg-1.. e ••••ig 1, ....,1 1 I 0 _, AkI.• , i411 111-4 7' 44 i •11---____ 11 WeriliNiehoW4.0.e - ...goli;,r,..-All, a i•t It W. PHOTO # 2 JFK PARKWAY AND EAST BOARDWALK DRIVE FORT COLLINS,COLORADO E ECEECPROJECTNo.1132068 SEPTEMBER 2013 N"-------_______---- . JFK PARKWAY AND EAST BOARDWALK DRIVE FORT COLLINS,COLORADO PROJECT NO: 1132068 LOG OF BORING B-1 DATE: SEPTEMBER 2013 RIG TYPE: CME55 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 9/5/2013 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 9/5/2013 AFTER DRILLING N/A SPT HAMMER: AUTOMATIC SURFACE ELEV NIA 24 HOUR N/A SOIL DESCRIPTION D N OU MC DD A-LIMITS 200 SWELL TVPE (FEET) (BLOWS/FT) (PSF)PCF) LL PI (%) PRESSURE I % 500 PSF SPARSE VEGETATION 1 SANDY LEAN CLAY(CL)-FILL brown 2 with sand/sandy zones SS 3 6 9000+ 9.1 4 CS 5 19 3000 11.7 110.8 32 12 58.7 <500 psi 3.5% SILTSTONE/CLAYSTONE/SANDSTONE brown/grey/rust 6 moderately hard 7 8 9 SS 1-0 50/6" 3000 13.3 1-1 1-2 1-3 1-4 CS 15 50/2" 5000 8.2 101.1 600 psi 0.3% 1-6 1-7 1-8 1-9 SS 2-0 50/5" 5000 12.3 2-1 22 2-3 2-4 CS 25 50/4" 9000+ 11.4 99.1 Continued on Sheet 2 of 2 Earth Engineering Consultants,LLC JFK PARKWAY AND EAST BOARDWALK DRIVE FORT COLLINS,COLORADO PROJECT NO: 1132068 LOG OF BORING B-1 DATE: SEPTEMBER 2013 RIG TYPE: CME55 SHEET 2 OF 2 WATER DEPTH FOREMAN: DG START DATE 9/5/2013 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 9/5/2013 AFTER DRILLING_ NIA SPT HAMMER: AUTOMATIC SURFACE ELEV N/A 24 HOUR NIA SOIL DESCRIPTION D N CID MC DD A-LIMITS 250 SWELL 1.1I.E (FEET) (BLOWS/FT) (PSF)PCF) LL PI (%) PRESSURE %5 500 PSF Continued from Sheet 1 of 2 26 SILTSTONE I CLAYSTONE/SANDSTONE 27 brown/grey/rust moderately hard 28 2-9 SS 3-0 50/5" 3000 12.8 BOTTOM OF BORING DEPTH 30.5' 31 3-2 3-3 34 35 3-6 3-7 3-8 39 40 41 42 43 44 45 46 47 4-8 49 5-0 Earth Engineering Consultants JFK PARKWAY AND EAST BOARDWALK DRIVE FORT COLLINS,COLORADO PROJECT NO: 1132068 LOG OF BORING B-2 DATE: SEPTEMBER 2013 RIG TYPE: CME55 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 9/5/2013 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 9/5/2013 AFTER DRILLING N/A SPT HAMMER: AUTOMATIC SURFACE ELEV N/A 24 HOUR N/A SOIL DESCRIPTION D N OU MC DD A-LIMITS 200 SWELL I TYPE (FEET) (BLOWS/FT) (PSF)PCF) LL PI (%) PRESSURE %@ 500 PSF SPARSE VEGETATION SANDSTONE/SILTSTONE-FILL 1 brown/grey/rust 2 SILTSTONE/SANDSTONE/CLAYSTONE CS -3 41 9000+ 7.1 121.1 brown/grey/rust moderately hard 4 CS -5 50/6" 9000+ 7.3 116.5 2000 psf 2.4% 6 7 8 9 SS 10- 50/7" 9000+ 13.1 11 12 1-3 1-4 CS 1-5- 50/5" 7000 12.5 117.6 1200 psf 0.5% BOTTOM OF BORING DEPTH 15.0' 16 1-7 1-8 1-9 2-0 21 2-2 2-3 2-4 2-5 Earth Engineering Consultants,LLC JFK PARKWAY AND EAST BOARDWALK DRIVE FORT COLLINS,COLORADO PROJECT NO: 1132068 LOG OF BORING B-3 DATE: SEPTEMBER 2013 RIG TYPE: CME55 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 9/5/2013 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 9/5/2013 AFTER DRILLING N/A SPT HAMMER: AUTOMATIC SURFACE ELEV N/A 24 HOUR N/A SOIL DESCRIPTION D N QU MC DO A-LIMITS 200 SWELL TYPE (FEET) (BLOWS/FT) (PSF)PCF) LL PI (%) PRESSURE % 500 PSF SANDY LEAN CLAY(CL)-FILL 1 mottled 2 CS 3 23 9000+ 8.4 127.6 33 16 54.1 CLAYEY SAND/SANDY LEAN CLAY(SC/CL) 4 brown/grey/rust medium dense SS 5 18 3000 8.8 6 7 8 9 CS 1-0 50 8000 15.4 112.1 32 15 68.9 1300 psf 0.7% SILTSTONE/CLAYSTONE/SANDSTONE brown/rust/grey 11 moderately hard 12 1-3 14 SS 1-5 50/6"13.9 BOTTOM OF BORING DEPTH 15.5' 16 1-7 1-8 1-9 2-0 2-1 22 2-3 2-4 2-5 Earth Engineering Consultants,LLC JFK PARKWAY AND EAST BOARDWALK DRIVE FORT COLLINS,COLORADO PROJECT NO: 1132068 LOG OF BORING B-4 DATE: SEPTEMBER 2013 RIG TYPE: CME55 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 9/5/2013 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 9/5/2013 AFTER DRILLING N/A SPT HAMMER: AUTOMATIC SURFACE ELEV N/A 24 HOUR N/A SOIL DESCRIPTION D N OU MC DD A-LIMITS 200 SWELL TYPE (FEET) (BLOWS/FT) (PSF)PCF) LL PI® (%) PRESSURE %/2;500 PSF SPARSE VEGETATION 1 LEAN CLAY(CL)-FILL brown 2 mottled xateopsf CS 3 13 9000+ 9.4 1192 3200 psf 4.4% 4 SILTY SANDY LEAN CLAY(CL) brown/grey/rust SS 5 13 8000 12.8 very stiff 6 SILTSTONE/CLAYSTONE/SANDTONE brown/grey!rust 7 moderately hard 8 9 SS 1-0 50/6" 7000 13.2 BOTTOM OF BORING DEPTH 10 5' 1-1 12 1-3 1-4 1-5 16 1-7 1-8 19 20 21 2- 2 2-3 24 25 Earth Engineering Consultants,LLC JFK PARKWAY AND EAST BOARDWALK DRIVE FORT COLLINS,COLORADO PROJECT NO: 1132068 LOG OF BORING B-5 DATE: SEPTEMBER 2013 RIG TYPE: CME55 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 91512013 WHILE DRILLING None _ AUGER TYPE: 4"CFA FINISH DATE 9/512013 AFTER DRILLING N/A SPT HAMMER: AUTOMATIC SURFACE ELEV N/A 24 HOUR N/A SOIL DESCRIPTION D N CU MC DD A-LIMITS 200 SWELL TYPE (FEET) (BLOWS/FT) (PSF)PCF) LL PI . I%I PRESSURE %a 500 PSF SPARSE VEGETATION 1 CLAYEY SAND/SANDY LEAN CLAY(SC/CL) brown/grey/rust 2 CS 3 25 5000 11.5 117.3 SILTSTONE/SANDSTONE/CLAYSTONE brown/grey/rust 4 moderately hard SS 5 50 3000 14.4 6 7 8 9 SS 1-0 5017" 5000 13.0 BOTTOM OF BORING DEPTH 10 5' 11 1-2 13 1-4 15 1-6 1-7 1-8 1-9 20 2-1 2-2 2-3 2-4 25 Earth Engineering Consultants,LLC SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Sandy Lean Clay(CL)- Fill Sample Location:Boring 1, Sample 2, Depth 4' Liquid Limit: 32 Plasticity Index: 12 Passing#200: 58.7% Beginning Moisture: 11.7% Dry Density: 118.1 pcf Ending Moisture: 16.7% Swell Pressure: <500 psf Swell @ 500: 3.5% 10.0 8.0 6.0 a) 4.0 2.0 d E 0.0 dU n. 2.0 Water Added 0 4.0 co 0 C o -6.0 U 8.0 10.0 0.01 0.1 1 10 Load(TSF) Project: JFK Parkway and East Boardwalk Drive Location: Fort Collins, Colorado EECProject#: 1132068 Date:September 2013 SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown/Grey/Rust Siltstone/Claystone/Sandstone Sample Location:Boring 1, Sample 4, Depth 14' Liquid Limit: -- Plasticity Index: -- Passing#200: -- Beginning Moisture: 8.2% Dry Density: 107.2 pcf Ending Moisture: 22.8% Swell Pressure: 600 psf Swell @ 500: 0.3% 10.0 8.0 6.0 a cn 4.0 2.0 d E d E 0.0 c a) J a)"a Water Added2.0 4.0 o I) a -6.0 U 8.0 - 10.0 0.01 0.1 1 10 Load(TSF) Project: JFK Parkway and East Boardwalk Drive Location: Fort Collins, Colorado Project#: 1132068 EEC ) Date:September 2013 SWELL /CONSOLIDATION TEST RESULTS Material Description: Claystone/Siltstone/Sandstone Sample Location:Boring 2, Sample 2, Depth 4' Liquid Limit: -- Plasticity Index: -- Passing#200: -- Beginning Moisture: 7.3% Dry Density: 109.6 pcf Ending Moisture: 20.2% Swell Pressure: 2000 psf Swell @ 500: 2.4% 10.0 8.0 6.0 0D 4.0 2.0 d 2 0.0 a - 2.0 Water Added 4.0 0 Co 0 U) o -6.0 U 8.0 10.0 0.01 0.1 1 10 Load(TSF) Project: JFK Parkway and East Boardwalk Drive Location: Fort Collins, Colorado EEC )Project#: 1132068 Date:September 2013 SWELL / CONSOLIDATION TEST RESULTS Material Description: Claystone/Siltstone/Sandstone Sample Location:Boring 2, Sample 4, Depth 14' Liquid Limit: -- Plasticity Index: -- Passing#200: -- Beginning Moisture: 12.5% Dry Density: 121 pcf Ending Moisture: 8.7% Swell Pressure: 1200 psf Swell @ 500: 0.5% 10.0 8.0 6.0 cn 4.0 2.0 c m E a) 100 a - 2.0 Water Added 4.0 a0 0 0 o -6.0 0 8.0 10.0 0.01 0.1 1 10 Load(TSF) Project: JFK Parkway and East Boardwalk Drive Location: Fort Collins, Colorado E E C,Project#: 1132068 Date:September 2013 SWELL /CONSOLIDATION TEST RESULTS Material Description: Brown I Rust I Grey Siltstone I Claystone I Sandstone Sample Location:Boring 3, Sample 3, Depth 9' Liquid Limit: 32 Plasticity Index: 15 Passing#200: 68.9% Beginning Moisture: 15.4% Dry Density: 119.1 pcf Ending Moisture: 17.6% Swell Pressure: 1300 psf Swell @ 500: 0.7% 10.0 8.0 6.0 a) 4.0 2.0 d E a) E 0.0 cu 2.0 Water Added 4.0 0 0 o -6.0 U 8.0 10.0 0.01 0.1 1 10 Load(TSF) Project: JFK Parkway and East Boardwalk Drive Location: Fort Collins, Colorado Project#: 1132068 Date:September 2013 r - SWELL /CONSOLIDATION TEST RESULTS Material Description: Brown Lean Clay(CL) Sample Location:Boring 4, Sample 1, Depth 2' Liquid Limit: -- Plasticity Index: -- Passing#200: -- Beginning Moisture: 9.4% Dry Density: 119.1 pcf Ending Moisture: 15.6% Swell Pressure: 3200 psf Swell @ 150: 4.4% 10.0 8.0 - 6.0 4.0 2.0 I d 0 E 0.0 c l d d Water Added 2.0 4.0 0 co o -6.0 0 8.0 10.0 0.01 0.1 1 10 Load(TSF) Project: JFK Parkway and East Boardwalk Drive Location: Fort Collins, Colorado w Project#: 1132068 1L--(v' Date:September 2013