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HomeMy WebLinkAboutHARMONY TECHNOLOGY PARK THIRD - Filed SEPD-SURFACE EXPLORATION/PAVEMENT DESIGN REPORT -z PRELIMINARY GEOTECHNICAL ENGINEERING REPORT AND PAVEMENT THICKNESS DESIGN HARMONY TECHNOLOGY PARK, 3rd FILING NORTHEAST CORNER OF ROCK CREEK DRIVE AND TECHNOLOGY PARKWAY FORT COLLINS, COLORADO Terracon Project No. 20085012 March 14, 2008 Prepared for. MAV DEVELOPMENT 303 DETROIT STREET ANN ARBOR, MICHIGAN 48104 Attn: MR. MIKE GENRICH Prepared by. Terracon Consultants, Inc. 301 North Howes Street Fort Collins, Colorado 80521 Phone: 970-484-0359 Fax: 970-484-0454 1rerracon March 14, 2008 Mav Development 303 Detroit Street Ann Arbor, Michigan 48104 Attn: Mr. Mike Genrich Re: Preliminary Geotechnical Engineering Report and Pavement Thickness Design Harmony Technology Park, 3rd Filing Northeast Corner of Rock Creek Drive and Technology Parkway Fort Collins, Colorado Terracon Project No. 20085012 Irerracon Consulting Engineers & Scientists 1289 First Avenue Greeley, Colorado 80631 Phone 970.351.0460 Fax 970.353.8639 www.terracon.com Terracon has completed the preliminary geotechnical engineering exploration for the proposed Harmony Technology Park, 3rd Filing to be located on the N/E/C of Rock Creek Drive and Technology Parkway in Fort Collins, Colorado. This study was performed in general accordance with our proposal number D2008065 dated February 18, 2008. The results of our engineering study are attached. These results include the Boring Location Diagram, laboratory test results, Logs of Borings, and the preliminary geotechnical recommendations needed to aid in the design and construction of foundations and other earth connected phases of this project. We appreciate being of service to you in the geotechnical engineering phase of this project, and are prepared to assist you during the construction phases as well. Please do not hesitate to contact us if you have any questions concerning this report or any of our testing, inspection, design and consulting services. qinr-araly RaynTond t. Denton Geotechnical Deoar Copies to: Addressee (5) f, Reviewed by: Ed Paas, P.E. Principal Delivering Success for Clients and Employees Since 1965 11 More Than 95 Offices Nationwide Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 TABLE OF CONTENTS Page No. Letterof Transmittal.............................................................................................................. ii INTRODUCTION..................................................................................................................1 PROJECTINFORMATION...................................................................................................1 SITEEXPLORATION........................................................................................................... 2 FieldExploration............................................................................................................. 2 LaboratoryTesting.......................................................................................................... 2 SITECONDITIONS..............................................................................................................3 SUBSURFACE CONDITIONS..............................................................................................3 Soil and Bedrock Conditions........................................................................................... 4 Field and Laboratory Test Results................................................................................... 4 GroundwaterConditions................................................................................................. 4 PRELIMINARY ENGINEERING RECOMENDATIONS........................................................5 FoundationSystems.......................................................................................................6 Lateral Earth Pressures..................................................................................................6 Detention Basin Recommendations................................................................................ 7 Seismic Considerations................................................................................................... 7 Floor Slab Design and Construction................................................................................ 7 Preliminary Pavement Design and Construction.............................................................8 Compliance...................................................................................................................11 Pavement Performance................................................................................................11 Earthwork......................................................................................................................12 General Considerations...........................................................................................12 SitePreparation......................................................................................................12 Subgrade Preparation............•................................................................................13 Fill Materials and Placement...................................................................................13 Shrinkage................................................................................................................15 Slopes.....................................................................................................................15 Excavation and Trench Construction.......................................................................15 Additional Design and Construction Considerations......................................................16 Exterior Slab Design and Construction....................................................................16 Underground Utility Systems...................................................................................16 Corrosion Protection................................................................................................17 GENERAL COMMENTS.....................................................................................................18 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 BORING LOCATION DIAGRAM.........................................................................Figure No. 1 APPENDIX A: LOGS OF BORING APPENDIX B: LABORATORY TEST RESULTS APPENDIX C: GENERAL NOTES iv PRELIMINARY GEOTECHNICAL ENGINEERING REPORT AND PAVEMENT THICKNESS DESIGN HARMONY TECHNOLOGY PARK, 3RD FILING NORTHEAST CORNER OF ROCK CREEK DRIVE AND TECHNOLOGY PARKWAY FORT COLLINS, COLORADO Terracon Project No. 20085012 March 14, 2008 INTRODUCTION This report contains the results of our preliminary geotechnical engineering exploration for the proposed project to be located on the N/E/C of Rock Creek Drive and Technology Parkway in Fort Collins, Colorado. The purpose of these services is to provide information and preliminary geotechnical engineering recommendations relative to: subsurface soil and bedrock conditions. groundwater conditions. foundation design and construction. basement construction. lateral earth pressures. floor slab design and construction. pavement design and construction. earthwork. drainage. The recommendations contained in this report are based upon the results of field and laboratory testing, engineering analyses, our experience with similar soil conditions and structures, and our understanding of the proposed project. Previously, Terracon performed geotechnical engineering services at the site for portions of Filing 2 (adjacent and north of this site) and preliminary pavement design recommendations for portions of Technology Parkway, Timberwood Drive, and Precision Drive. For further information on the previous study please reference Terracon Project No. 20005198 dated March 21, 2001. PROJECT INFORMATION Based on information provided by Stantec, the proposed project will include the development of three (3) commercial/industrial lots. At this time the proposed structures have not been determined and therefore, the foundations recommendations presented herein are preliminary. Grading plans indicate cut and fill depths on the order of about 3 feet with some deeper cut 1 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 depths associated with construction of a detention basin area at the southwest corner of the site. Other major site development will include the installation of utilities, as well as the construction of asphalt concrete or Portland cement concrete paved streets. Traffic loading criteria for preliminary pavement thickness designs have been estimated based on the classifications provided by Stantec and the Larimer County Urban Area Street Standards (LCUASS). SITE EXPLORATION PROCEDURES The scope of the services performed for this project included site reconnaissance by an engineering geologist, a subsurface exploration program, laboratory testing and preliminary engineering analysis. Field Exploration: A total of 6 test borings were drilled on February 21 and February 27, 2008 to depths of about 9 to 30 feet below existing site grade at the approximate locations shown on the Boring Location Diagram, Figure 1. Three (3) borings were drilled at the approximate lot centers of Lots 1, 3, and 4, two (2) borings were drilled in the area of proposed pavements, and 1 boring was drilling in a proposed detention pond area. The borings were advanced with a truck -mounted drilling rig, utilizing 4-inch diameter solid -stem, continuous -flight auger. The borings were located in the field by pacing from property lines and/or existing site features. Elevations were taken at each boring location by measurements with an engineer's level from a temporary benchmark (TBM) shown on the Boring Location Diagram. The accuracy of boring locations and elevations should only be assumed to the level implied by the methods used. Lithologic logs of each boring were recorded by the engineering geologist during the drilling operations. At selected intervals, samples of the subsurface materials were taken by driving split -spoon and ring barrel samplers. Penetration resistance measurements were obtained by driving the split -spoon and ring barrel samplers into the subsurface materials with a 140-pound hammer falling 30 inches. The penetration resistance value is a useful index to the consistency, relative density or hardness of the materials encountered. Groundwater measurements were made in each boring at the time of site exploration, and within 6 days after drilling. Laboratory Testing: Samples retrieved during the field exploration were returned to the laboratory for observation by the project geotechnical engineer, and were classified in general accordance with the Unified Soil Classification System described in Appendix C. Samples of bedrock were classified in accordance with the general notes for Rock Classification. At that PA Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 time, an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials. Following the completion of the laboratory testing, the field descriptions were confirmed or modified as necessary and Logs of Borings were prepared. These logs are presented in Appendix A. Laboratory test results are presented in Appendix B. These results were used for the geotechnical engineering analyses and the development of preliminary foundation, pavment and earthwork recommendations. All laboratory tests were performed in general accordance with the applicable local or other accepted standards. Selected soil and bedrock samples were tested for the following engineering properties: Water content Dry density Consolidation Expansion SITE CONDITIONS Grain size Plasticity Index Water soluble sulfate content The site was vacant and to our knowledge had not been previously developed and was used for agricultural purposes. The site was bounded on the north by the proposed Filing 2 of Harmony Technology Park, on the east by Lady Moon Drive, on the south by Rock Creek Drive , and on the west by Technology Parkway (proposed, unpaved) with undeveloped property beyond. The approximate center of the site (Lot 2) contains the proposed Custom Blending Facility, which is not included as part of this study. The ground surface was generally flat to gently rolling at the time of our field exploration. Vegetation consisted of a moderate growth of native grasses and weeds. Site drainage was generally in the form of surface sheet flow directed to the south and east, although shallow depressions existed. SUBSURFACE CONDITIONS Geology: Surficial geologic conditions at the site, as mapped by the U.S. Geological Survey USGS) ('Colton, 1978), consist of residual and alluvial soils of Pleistocene Age. This material generally consists of silt, clays, and sands. These materials, as mapped in this area, are generally less than about 30 feet in thickness. Colton, Roger B., 1978, Geologic Map of the Boulder -Fort Collins -Greeley Area, Colorado, United States Geological Survey, Map 1-855-G. 3 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 Bedrock underlying the surface units consists of Pierre Shale of Upper Cretaceous Age. This formation is generally comprised of grey claystone and siltstone. The thickness of this unit has been reported to be on the order of 2,800 feet. The shale underlies the site at depths of about 13 to 28 feet below existing site grade. Due to the relatively flat nature of the site, geologic hazards at the site are anticipated to be low. Seismic activity in the area is anticipated to be low, and the property should be relatively stable from a structural standpoint. With proper site grading around proposed structures, erosional problems at the site should be reduced. Mapping completed by the Colorado Geological Survey (2Hart, 1972), indicates the site is located in an area of "Moderate Swell Potential'. Potentially expansive materials mapped in this area include bedrock, weathered bedrock and colluvium (surficial units). Soil and Bedrock Conditions: As presented on the Logs of Borings, surface soils to depths of about 6 inches consisted of topsoil. Lean clay with varying amounts of sand was encountered below the topsoil and extended to depths of about 13 to 28 feet. The materials underlying the surface soils in the deeper borings and extending down to the full depth of exploration consisted of claystone bedrock. Bedrock was not encountered to the full depth of exploration in Borings Nos. 5 and P6 to depths of 15 feet and 9 feet, respectively. Field and Laboratory Test Results: Field test results indicate that the clay overburden soils vary from medium stiff to hard in consistency. The claystone bedrock varies from weathered to medium hard in hardness. Laboratory test results indicate that the clay soils at shallow depth are relatively dry and hard with moderate to high expansion potential under light loading conditions such as those imposed by floor slabs and pavements. The claystone bedrock is considered to be moderately to highly expansive with high load carrying capability. Results of water soluble sulfate testing indicate a negligible sulfate concentration of 4 ppm. Groundwater Conditions: Groundwater was not observed in any test boring at the time of the field exploration. However, when checked within 6 days after drilling, groundwater was measured at depths of about 15 feet below existing site grade in test Boring Nos. 1, 2, and 4. These observations represent groundwater conditions at the time of the field exploration, and may not be indicative of other times or at other locations. Groundwater levels can be expected to fluctuate with varying seasonal and weather conditions. 2Hart, Stephen S., 1972, Potentially Swelling Soil and Rock in the Boulder -Fort Collins -Greeley Area, Front Range - Urban Corridor Colorado, Colorado Geological Survey, Sheet 1 of 4. 4 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 Based upon review of U.S. Geological Survey Maps, (3Hillier, et al, 1979), regional groundwater beneath the project area is expected to be encountered in unconsolidated alluvial deposits on the site at depths ranging from 10 to 20 feet below present ground surface. The possibility of groundwater fluctuations should be considered when developing design and construction plans for the project. PRELIMINARY ENGINEERING RECOMMENDATIONS The preliminary recommendations presented in this report are based on the assumption that the subsurface conditions do not deviate appreciably from those encountered in the borings. Supplementary geotechnical engineering exploration should be performed at the site upon completion of initial design studies. Supplemental geotechnical explorations will be used to confirm or modify the recommendations contained in this preliminary report. Expansive soils are present on this site. This report provides recommendations to help mitigate the effects of soil shrinkage and expansion. However, even if these procedures are followed, some movement and (at least minor) cracking in the structure should be anticipated. The severity of cracking and other cosmetic damage such as uneven floor slabs will probably increase if any modification of the site results in excessive wetting or drying of the expansive soils. Eliminating the risk of movement and cosmetic distress may not be feasible, but it may be possible to further reduce the risk of movement if the measures outlined in this report are implemented in the design and construction of the project. Some of these options are discussed in this report. We would be pleased to discuss other construction alternatives with you upon request. The site appears suitable for the proposed construction based on the preliminary geotechnical exploration and analysis. However, relatively dry and hard near surface materials with moderate to high expansion potential will require particular attention in the design and construction of the project. Spread footing foundations could be considered for support of lightly loaded structures (wall and column loads up to about 3 to 4 kips per foot and 75 to 100 kips, respectively) and drilled pier foundations should be considered for heavier structures. Based on the moderately to highly expansive near surface soils, overexcavation and replacement or recompaction could be required for shallow foundations and floor slabs. Preliminary swell testing indicates that site pavements will generally require swell mitigation in the form of overexcavation, moisture conditioning, and recompaction and/or replacement or fly ash treatment in order to reduce swell potential to less than 2 percent as required by the Hillier, Donald E.; and Schneider, Paul A., Jr., 1979, Depth to Water Table (1976-1977) in the Boulder -Fort Collins - Greeley Area, Front Range Urban Corridor, Colorado, United States Geological Survey, Map 1-855-I. 5 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3`d Filing Terracon Project No. 20085012 Larimer County Urban Area Street Standards (LCUASS). Final pavement design testing will be required subsequent to final grading and installation of underground utilities per LCUASS. Foundation Systems: Spread footing foundations bearing upon undisturbed subsoils, recompacted native soils and/or engineered fill are recommended for support of proposed lightly loaded structures (wall and column loads less than about 4 kips per foot and 75 to 100 kips, respectively). The footings may be preliminarily designed for maximum bearing pressures of approximately 1,500 to 2,000 pounds per square foot (psf). In addition, the footings may need to be sized to maintain minimum dead load pressures of about 500 to 750 psf. The preliminary design bearing pressures apply to dead loads plus design live load conditions. The preliminary design bearing pressure may be increased by 1/3 when considering total loads that include wind or seismic conditions. As previously outlined, some overexcavation could be required in order to use spread footing foundations or drilled piers could be considered. Drilled piers should also be considered for heavier structures than those outlined above. Supplemental geotechnical exploration and analysis will be required for site/structure specific designs. Lateral Earth Pressures: For soils above any free water surface, recommended equivalent fluid pressures for unrestrained foundation elements are: Active: Cohesive soil backfill (on -site clay or imported clay) ....................................... 55 psf/ft Cohesionless soil backfill (on -site or imported sand) ...................................... 35 psf/ft On -site bedrock materials .................................................... not recommended for use Passive: Cohesive soil backfill (on -site or imported clay) ............................................ 250 psf/ft Cohesionless soil backfill (on -site or imported sand) .................................... 350 psf/ft Coefficient of base friction.................................................................................... 0.35 The coefficient of base friction should be reduced to 0.30 when used in conjunction with passive pressure. Where the design includes restrained elements, the following equivalent fluid pressures are recommended: At rest: Cohesive soil backfill (on -site or imported clay) ........... Cohesionless soil backfill (on -site or imported sand) ... On -site bedrock materials ............................................ 75 psf/ft 55 psf/ft not recommended for use 1 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3rd Filing Terracon Project No. 20085012 The lateral earth pressures herein do not include any factor of safety and are not applicable for submerged soils/hydrostatic loading. Additional recommendations may be necessary if submerged conditions are to be included in the design. Fill against foundations and retaining walls should be compacted to densities specified in the Earthwork" section of this report. Medium to high plasticity clay soils or claystone shale should not be used as backfill against retaining walls. Compaction of each lift adjacent to walls should be accomplished with hand -operated tampers or other lightweight compactors. Overcompaction may cause excessive lateral earth pressures which could result in wall movement. Detention Basin Recommendations: Groundwater was not encountered to the depth of exploration, approximately 15 feet in the boring (Boring No. 5) drilled within the proposed detention basin area. Based on the current groundwater conditions in the location of the proposed detention basin, it is our opinion the site will be suitable for the basin construction. The subgrade soils encountered in this area generally consisted of sandy lean clays which are generally suitable for containment of water. The upper 8 to 12 inches of the wetted perimeter of the pond including the bottom of the pond and cut slopes of the pond should be scarified and recompacted to within plus or minus 2 percent of optimum moisture and to a minimum of 95 percent of Standard Proctor Density ASTM D698. Infiltration and/or permeability testing is beyond the scope of this study, but can be provided if requested. Seismic Considerations: A site classification "C" should be used for the design of structures for the proposed project (2003 International Building Code, Table No. 1613.5.2). Floor Slab Design and Construction: Non -expansive or only low expansive soils or engineered fill will support the floor slab. As previously outlined, some overexcavation and recompaction and/or replacement of the near surface clays may be required for support of floor slabs. Differential movement of a slab -on -grade floor system is possible should the subgrade soils become elevated in moisture content. To reduce potential slab movements, the subgrade soils should be prepared as outlined in the "Earthwork" section of this report. For preliminary structural design of concrete slabs -on -grade, a modulus of subgrade reaction of 75 pounds per cubic inch (pci) may be used for floors supported on existing or engineered fill consisting of on -site soils. A modulus of 200 pci may be used for floors supported on non - expansive imported fill meeting the specifications outlined below. Additional floor slab design and construction recommendations are as follows: Positive separations and/or isolation joints should be provided between slabs and all foundations, columns or utility lines to allow independent movement. 7 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, V Filing Terracon Project No. 20085012 Control joints should be provided in slabs to control the location and extent of cracking. A minimum 1-1/2 to 2-inch void space should be constructed above or below non - bearing partition walls placed on the floor slab. Special framing details should be provided at doorjambs and frames within partition walls to avoid potential distortion. Partition walls should be isolated from suspended ceilings. Interior trench backfill placed beneath slabs should be compacted in accordance with recommended specifications outlined below. The use of a vapor retarder should be considered beneath concrete slabs on grade that will be covered with wood, tile, carpet or other moisture sensitive or impervious coverings, or when the slab will support equipment sensitive to moisture. When conditions warrant the use of a vapor retarder, the slab designer and slab contractor should refer to ACI 302 for procedures and cautions regarding the use and placement of a vapor retarder. Floor slabs should not be constructed on frozen subgrade. Other design and construction considerations, as outlined in Section 302A R of the ACI Design Manual, are recommended. Preliminary Pavement Design and Construction: Preliminary design of pavements for the project have been based on the procedures outlined in the 1993 Guideline for Design of Pavement Structures by the American Association of State Highway and Transportation Officials (AASHTO) and the Larimer County Urban Area Street Standards (LCUASS). As discussed, the design presented herein is for preliminary planning purposes for the project. Subsequent to final grading and installation of utilities, a pavement design report meeting LCUASS specifications will need to be prepared for submittal. Based upon AASHTO criteria, Colorado is located within Climatic Region VI of the United States. This region is characterized as being dry, with hard ground freeze and spring thaw. The spring thaw condition typically results in saturated or near -saturated subgrade soil moisture conditions. The AASHTO criteria suggest that these moisture conditions are prevalent for approximately 12-1/2 percent of the annual moisture variation cycle. Local drainage characteristics of proposed pavement areas are considered to vary from fair to good depending upon location on the site. For purposes of this preliminary design analysis, fair drainage characteristics are considered to control the design. These characteristics, coupled with the approximate duration of saturated subgrade conditions, result in a design drainage coefficient of 1.0 when applying the AASHTO criteria for design. 1.1 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 For preliminary flexible pavement design, a terminal serviceability index of 2.3 was utilized along with an inherent reliability of 85 percent and a design life of 20 years. Using the correlated design R-value of 10 (also based on our previously referenced geotechnical study from other portions of the site), appropriate ESAL, environmental criteria and other factors, the structural numbers (SN) of the pavement sections were determined on the basis of the 1993 AASHTO design equation. In addition to the preliminary flexible pavement design analyses, a preliminary rigid pavement design analysis was completed based upon AASHTO design procedures. Rigid pavement design is based on an evaluation of the Modulus of Subgrade Reaction of the soils (K-value), the Modulus of Rupture of the concrete, and other factors previously outlined. The preliminary design K-value of 100 for the subgrade soil was determined by correlation to the laboratory test results. A modulus of rupture of 650 psi (working stress 488 psi) was used for pavement concrete. The rigid pavement thickness for each traffic category was determined on the basis of the AASHTO design equation. Preliminary alternatives for flexible and rigid pavements, summarized for each traffic area, are as follows: Recommended Pavement Thickness (Inches) Asphalt Aggregate Fly Ash PortlandTrafficAreaAlternative Concrete Base Treated Cement Total Surface Course Subgrade Concrete Precision A' 5 7 12 Drive Industrial B 5 7 12 24 Local ESAL = C. 8 8365,000) Technology A' 6 6 12 Parkwaylnd ustrial B 6 6 12 24 Collector ESAL = C' 7 7 730,000) Alternatives A and C will likely require overexcavation, moisture conditioning, and recompaction of the upper 2 feet of subgrade for swell mitigation in accordance with LCUASS Each alternative should be investigated with respect to current material availability and economic conditions. 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, or rainfall. As a result, the pavement subgrade may not be 9 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 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 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. We recommend the pavement areas be rough graded and then thoroughly proofrolled with a loaded tandem axle dump truck prior to final grading and paving. Particular attention should be paid to high traffic areas and to areas where backfilled trenches are located. Areas where unsuitable conditions are located should be repaired by removing and replacing the materials with properly compacted fills. Pavement areas should be moisture conditioned and properly compacted to the recommendations in this report immediately prior to paving. The placement of a partial pavement thickness for use during construction is not suggested without a detailed pavement analysis incorporating construction traffic. In addition, we should be contacted to confirm the traffic assumptions outlined above. If the actual traffic varies from the assumptions outlined above, modification of the pavement section thickness will be required. Aggregate base course (if used on the site) should consist of a blend of sand and gravel which meets strict specifications for quality and gradation. Use of materials meeting Colorado Department of Transportation (CDOT) Class 5 or 6 specifications is recommended for base course. Aggregate base course and select subbase should be placed in lifts not exceeding 6 inches and compacted to a minimum of 95 percent standard Proctor density (ASTM D698).. Asphalt concrete should be composed of a mixture of aggregate, filler and additives (if required) and approved bituminous material. The asphalt concrete should conform to approved mix designs stating the superpave volumetric properties, optimum asphalt content, job mix formula and recommended mixing and placing temperatures. Aggregate used in asphalt concrete should meet particular gradations. Material meeting CDOT Grading S or SG specifications or equivalent is recommended for asphalt concrete. Mix designs should be submitted prior to construction to verify their adequacy. Asphalt material should be placed in minimum/maximum lifts of 2/3.5 and 3/5-inches for grading S and SG; respectively, and compacted to the specifications outlined in the mix design. The asphalt binder grading should be selected based upon the local government entity input. Where rigid pavements are used, the concrete should be obtained from an approved mix design with the following minimum properties: Modulus of Rupture @ 28 days........................................................... 600 psi minimum Strength Requirements.................................................................................ASTM C94 Cement Type......................................................................................... Type I Portland 10 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3`d Filing Terracon Project No. 20085012 Entrained Air Content......................................................................................... 6 to 8% Concrete Aggregate ................................................ ASTM C33 and CDOT Section 703 Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 minutes from the time the water is added to the mix. Other specifications outlined by CDOT should be followed. Longitudinal and transverse joints should be provided as needed in concrete pavements for expansion/contraction and isolation per ACI 325.12R-02. The location and extent of joints should be based upon the final pavement geometry. Joints should be sealed to prevent entry of foreign material and doweled where necessary for load transfer. Compliance: Recommendations for pavement construction presented depend upon compliance with recommended material specifications. To assess compliance, observation and testing should be performed under the direction of the geotechnical engineer. Pavement Performance: 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 a potentially expansive clay subgrade such as the soils encountered on this project. 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. Since the clay soils on the site have shrink/swell characteristics, pavements could crack in the future primarily because of expansion of the soils when subjected to an increase in moisture content to the sub -grade. The cracking, while not desirable, does not necessarily constitute structural failure of the pavement. The performance of pavements can be enhanced by minimizing excess moisture which can reach the subgrade soils. The following recommendations should be considered at minimum: site grading at a minimum 2 percent grade away from the pavements. the sub -grade and the pavement surface have a minimum 1/4 inch per foot slope to promote proper surface drainage. consider appropriate edge drainage and pavement underdrain systems. install pavement drainage surrounding areas anticipated for frequent wetting. install joint sealant and seal cracks immediately. compaction of any utility trenches for landscaped areas to the same criteria as the pavement sub -grade. 11 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3rd Filing Terracon Project No. 20085012 seal landscaped areas in or adjacent to pavements to minimize or prevent moisture migration to sub -grade soils. place compacted, low permeability backfill against the exterior side of curb and gutter. place curb, gutter and/or sidewalk directly on sub -grade soils without the use of base course materials. Drainage Adjacent to Pavements: The clay subgrade materials will expand and/or lose stability with increases in moisture content. Therefore, to reduce pavement distress due to wetting of the subgrade in areas of water intensive landscaping or other nearby water sources or if aggregate base course is used) located adjacent to pavements, we recommend that shoulder installation of drains be considered. The drain system should consist of a properly sized pipe embedded in free -draining material directed to a suitable outfall such as an underdrain or storm sewer. Earthwork: General Considerations: The following presents recommendations for site preparation, excavation, subgrade preparation and placement of engineered fills on the project. All earthwork on the project should be observed and evaluated by Terracon. The evaluation of earthwork should include observation and testing of engineered fills, subgrade preparation, foundation bearing soils and other geotechnical conditions exposed during the construction of the project. Site Preparation: Strip and remove existing vegetation and other deleterious materials from proposed building and pavement areas. All exposed surfaces should be free of mounds and depressions which could prevent uniform compaction. Stripped materials consisting of vegetation and organic materials should be wasted from the site or used to revegetate landscaped areas or exposed slopes after completion of grading operations. If it is necessary to dispose of organic materials on -site, they should be placed in non-structural areas and in fill sections not exceeding 5 feet in height. The site should be initially graded to create a relatively level surface to receive fill and to provide for a relatively uniform thickness of fill beneath proposed structures. If fill is placed in areas of the site where existing slopes are steeper than 5:1 horizontal:vertical), the area should be benched to reduce the potential for slippage between existing slopes and fills. Benches should be wide enough to accommodate compaction and earth moving equipment and to allow placement of horizontal lifts of fill. 12 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3`d Filing Terracon Project No. 20085012 All exposed areas which will receive fill, once properly cleared and benched, should be scarified to a minimum depth of 8 inches, conditioned to near optimum moisture content and compacted. Although evidence of fills or underground facilities such as septic tanks, cesspools, basements and utilities was not observed during the site reconnaissance, such features could be encountered during construction. If unexpected fills or underground facilities are encountered, such features should be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction. It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. Depending upon depth of excavation and seasonal conditions, groundwater may be encountered in excavations on the site. Pumping from sumps may be utilized to control water within excavations. Well points may be required for significant groundwater flow, or where excavations penetrate groundwater to a significant depth. The stability of the subgrade may be affected by proximity to groundwater, precipitation, repetitive construction traffic or other factors. If unstable conditions are encountered or develop during construction, workability may be improved by scarifying and drying. Overexcavation of wet zones and replacement with granular materials may be necessary. Use of lime, fly ash, kiln dust, cement or geotextiles could also be considered as a stabilization technique. Laboratory evaluation is recommended to determine the effect of chemical stabilization on subgrade soils prior to construction. Lightweight excavation equipment may be required to reduce subgrade pumping. The individual contractor(s) is 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 in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. Subgrade Preparation: Subgrade soils beneath interior and exterior slabs and beneath pavements should be scarified, moisture conditioned and compacted to a minimum depth of 8 inches. The moisture content and compaction of subgrade soils should be maintained until slab or pavement construction. Fill Materials and Placement: Clean on -site soils or approved imported materials may be used as fill material. Imported soils (if required) should conform to the following: 13 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3rd Filing Terracon Project No. 20085012 Percent finer by weight Gradation (ASTM C136) 611 ..................................................................................................................... 100 311 ................................................................................................................ 70-100 No. 4 Sieve................................................................................................. 50-100 No. 200 Sieve..........................................................................................50 (max) Liquid Limit......................................................................................... 30(max) Plasticity Index...................................................................................15 (max) Maximum expansive potential(%)*............................................................. 1.5 Measured on a sample compacted to approximately 95 percent of the ASTM D698 maximum dry density at about 3 percent below optimum water content. The sample is confined under a 500 psf surcharge and submerged. Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. Recommended compaction criteria for engineered fill is 95 percent of the maximum dry density (ASTM D698). On -site or imported clay soils should be compacted within a moisture content range of 0 percent below to 2 percent above optimum. On -site or imported sands should be compacted within a moisture range of 3 percent below to 3 percent above optimum unless modified by the project geotechnical engineer. The recommendations for placement and compaction criteria presented assume that fill depths will be less than 8 feet. Fills less than 8 feet, when placed and compacted as recommended in this report, will experience some settlement (generally 1 inch or less). The amount and rate of settlement will be increased if water is introduced into the fill. If fill depths exceed 8 feet, modifications to the backfill materials, placement and compaction criteria may be required or appreciable settlement may occur. The final grading plans should be reviewed with Terracon where fill depths of 8 feet or more are proposed. 14 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 Shrinkage: For balancing grading plans, the estimated shrink or swell of soils and bedrock when used as compacted fill following recommendations in this report are as follows: Material Estimated Shrink (-) Swell (+) Based on ASTM D698 On -site soils: Sandyclays.....................................................................................-5 to -10% On -site bedrock materials: Claystone........................................................................................... 0 to +5% Slopes: For permanent slopes in compacted fill or cut areas, recommended maximum configurations for on -site materials are as follows: Material Maximum Slope Horizontal:Vertical Cohesive soils (on -site or imported clays)........................................................ 3:1 Cohesionless soils (on -site or imported sands)...........................................2-1/2:1 Bedrock............................................................................................................ 2:1 If steeper slopes are required for site development, stability analyses should be completed to design the grading plan. The face of all slopes should be compacted to the minimum specification for fill embankments. Alternately, fill slopes can be overbuilt and trimmed to compacted material. Saturation or near saturation of the slopes could result in slope failure, even if the slopes are constructed to the recommended configurations. If saturated conditions are likely, due to irrigation, surface flows or other sources, Terracon should be informed and stability analyses should be performed. Excavation and Trench Construction: Excavations into the on -site soils will encounter a variety of conditions. Excavations into the clays and bedrock can be expected to stand on relatively steep temporary slopes during construction. However, caving soils may also be encountered. 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 in the interest of 15 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 safety following local and federal regulations, including current OSHA excavation and trench safety standards. For this site, the overburden soils consisting of clays can be considered Type B soils and the claystone shale as "stable rock" when applying the OSHA regulations. OSHA recommends a maximum slope inclination of 1:1 (horizontal to vertical) for Type B soils in excavations of 20 feet or less. Flatter slopes may be required if caving soils or seepage is encountered in any excavation. If any excavation (including a utility trench) is extended to a depth of more than 20 feet, it will be necessary to have the side slopes designed by a professional engineer. The soils to be penetrated by the proposed excavations may vary significantly across the site. The preliminary soil classifications are based solely on the materials encountered in widely spaced exploratory test borings. The contractor should verify that similar conditions exist throughout the proposed area of excavation. If different subsurface conditions are encountered at the time of construction, the actual conditions should be evaluated to determine any excavation modifications necessary to maintain safe conditions. As a safety measure, it is recommended that all vehicles and soil piles be kept to a minimum lateral distance from the crest of the slope equal to no less than the slope height. The exposed slope face should be protected against the elements. Additional Design and Construction Considerations: Exterior Slab Design and Construction: Compacted subgrade or existing clay soils will expand with increasing moisture content; therefore, exterior concrete grade slabs may heave resulting in cracking or vertical offsets. The potential for damage would be greatest where exterior slabs are constructed adjacent to the building or other structural elements. To reduce the potential for damage, we recommend: exterior slabs be supported on fill with no, or very low, expansion potential. strict moisture -density control during placement of subgrade fills. placement of effective control joints on relatively close centers and isolation joints between slabs and other structural elements. provision for adequate drainage in areas adjoining the slabs. use of designs which allow vertical movement between the exterior slabs and adjoining structural elements. Underground Utility Systems: All piping should be adequately bedded for proper load distribution. It is suggested that clean, graded gravel compacted to 75 percent of relative density ASTM D4253 be used as bedding. Temporary dewatering will be required for proper construction during excavation, pipe placement and backfilling operations where utilities are 16 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3` d Filing Terracon Project No. 20085012 excavated below groundwater. Utility trenches should be excavated on safe and stable slopes in accordance with OSHA regulations as discussed above. Backfill should consist of the on -site soils or existing bedrock. If bedrock is used, all plus 6-inch material should be removed from it prior to its use. The pipe backfill should be compacted to a minimum of 95 percent of standard Proctor density ASTM D698. All underground piping within or near the proposed structures should be designed with flexible couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts in grade beams should be oversized to accommodate differential movements. It is strongly recommended that a representative of the geotechnical engineer provide full- time observation and compaction testing of trench backfill within building and pavement areas. Corrosion Protection: Results of soluble sulfate testing indicate that ASTM Type I Portland cement is suitable for all project concrete on and below grade. However, if there is no (or minimal) cost differential, use of ASTM Type II Portland cement is recommended for additional sulfate resistance of construction concrete. Foundation concrete should be designed in accordance with the provisions of Section 318, Chapter 4, of the ACI Design Manual. Surface Drainage: All grades must be adjusted to provide positive drainage away from the structure during construction and maintained throughout the life of the proposed project. Infiltration of water into utility or foundation excavations must be prevented during construction. Landscaped irrigation adjacent to the foundation system should be minimized or eliminated. Water permitted to pond near or adjacent to the perimeter of the structure (either during or post - construction) can result in significantly higher soil movements than those discussed in this report. As a result, any estimations of potential movement described in this report cannot be relied upon if positive drainage is not obtained and maintained, and water is allowed to infiltrate the fill and/or subgrade. Exposed ground should be sloped at a minimum of 10 percent grade for at least 10 feet beyond the perimeter of the building. Backfill against footings, exterior walls and in utility and sprinkler line trenches should be well compacted and free of all construction debris to reduce the possibility of moisture infiltration. After building construction and prior to project completion, we recommend that verification of final grading be performed to document that positive drainage, as described above, has been achieved. Flatwork and pavements will be subject to post construction movement. Maximum grades practical should be used for paving and flatwork to prevent areas where water can pond. In addition, allowances in final grades should take into consideration post -construction movement of flatwork, particularly if such movement would be critical. Where paving or flatwork abuts the 17 Preliminary Geotechnical Engineering Report and Pavement Thickness Design Terracon Harmony Technology Park, 3rd Filing Terracon Project No. 20085012 structure, care should be taken that joints are properly sealed and maintained to prevent the infiltration of surface water. Planters located adjacent to the structure should preferably be self-contained. Sprinkler mains and spray heads should be located a minimum of 5 feet away from the building line. Roof drains should discharge on pavements or be extended away from the structure a minimum of 5 feet through the use of splash blocks or downspout extensions. A preferred alternative is to have the roof drains discharge to storm sewers by solid pipe or daylighted to a detention pond or other appropriate outfall. GENERAL COMMENTS Supplemental exploration and analyses should be undertaken in order to develop final design parameters and to confirm and/or modify the preliminary recommendations and conclusions contained in this report. Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon should also be retained to provide testing and observation during the excavation, grading, foundation and construction phases of the project. The analysis and recommendations presented in this preliminary report are based upon the data obtained from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations that may occur between borings, across the site, or due to the modifying effects of weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified 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 environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken. This preliminary 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 generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that changes are planned in the nature, design, or location of the project as outlined in this report, the conclusions and recommendations contained in this report shall not be considered valid unless Terracon reviews the changes, and either verifies or modifies the conclusions of this report in writing. 18 r= W O W Z 0 Q (p o z = O W Oil O Z W U1 O U) > QU-ZEL LL R U- W 000 vw 0 -0 ZW HU)1- w U U mU) 000 a w0wU) F- t- ELF-0 O Z az¢Za 2O;R2OxP:x0W O z O m _ 0 W' WOfF- Z d l- (L u) ly QOQ F-Ii W J I I I E 0 NWin adr J 0 9E OK cO J U J 0p W In Oz N cQ APPENDIX A LOG OF BORING NO. 1 Page 1 of 1 ARCHITECT /ENGINEER MAV DEVELOPMENT SITE Rock Creek Dr. and Technology Pkwy. PROJECT Fort Collins, Colorado HARMONY TECHNOLOGY PARK, 3RD FILING SAMPLES TESTS U DESCRIPTION O M o a z = 2 a W O) n W z Z Z Z Approx. Surface Elev.: 94.6 ft a o U D 2 z a Ix p m h o o o. L) D U) TOPSOIL SANDY LEAN CLAY CL 1 SS 12 14 16Stifftoverystiff, brown Color change to reddish brown CL 2 RSI 12 14 17 107 5 Calcareous material observed CL 3 IRS 12 16 21 105 10 Color change olive to brown 1 CL 4 IRS. 12 16 23 105 15 CL 5 IRS 12 19 19 113 20 CL 6 RS 12 23 23 110525 28 66.6 CLAYSTONE Medium hard, olive, iron staining 7 RS1 12 78 18 112 30 64.6 30 BOTTOM OF BORING 00 The stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft Irerracon BORING STARTED 2-21-08 n WL DRY WD 1 15 AB BORING COMPLETED 2-27-08 z WL RIG CME 55 FOREMAN PDG y WL Water Level Reading 3/4/2008 APPROVED RLD JOB # 20085012 LOG OF BORING NO. 2 Page 1 of 1 MAV DEVELOPMENT ARCHITECT / ENGINEER SITE Rock Creek Dr. and Technology Pkwy. Fort Collins, Colorado PROJECT HARMONY TECHNOLOGY PARK, 3RD FILING 7 n c DESCRIPTION Approx. Surface Elev.: 96.4 ft W o 0O m rn U fn SAMPLES TESTS w Z) z a S W X to o J m X W Hz Q O 0 a 0 n W: tip Z Z° OWZ f- D U) TOPSOIL 5 10 15 20 25 SANDY LEAN CLAY Stiff to very stiff, brown Color change to reddish brown 14 82.4 CL 1 SS 12 18 14 CL 2 RS 12 14 16 110 CL 3 RS 12 15 20 108 CLAYSTONE 1 Weatheredtofirm, brown to olive, iron staining 714 BOTTOM OF BORING 4 RS 12 36 23 101 5 RS 12 22 25 103 N25 6 RS 22 103 The stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft BORING STARTED 2-21-08 WL Q DRY WD 1 15 AB BORING COMPLETED 2-27-08 WL 7IrerraconiRIG CME 55 FOREMAN PDG WL Water Level Reading 3/4/2008 APPROVED RLD JOB # 20085012 LOG OF BORING NO. 3 Page 1 of 1 ARCHITECT / ENGINEER MAV DEVELOPMENT SITE Rock Creek Dr. and Technology Pkwy. PROJECT Fort Collins, Colorado HARMONY TECHNOLOGY PARK, 3RD FILING SAMPLES TESTS DESCRIPTION C° o _ Ul 0 U) ZWcnxw ZZ W2 Approx. Surface Elev.: 96.9 ft o D z in F Z o o a o(n j A TOPSOIL SANDY LEAN CLAY Very Stiff, reddish brown CL 1 RS 12 22 14 116 5 1.5% CL 2 RS 12 32 20 108 10 500psf 13 83.9 15 CLAYSTONE with SAND Very stiff, brown to olive, iron staining 81.915 CL 3 RS 12 37 19 111 BOTTOM OF BORING s s i i The stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft BORING STARTED 2-27-08 WL 7 DRY WD 1 DRY AB BORING COMPLETED 2-27-08 WL TIrerracon RIG CME 55 FOREMAN PDG 5 WL Water Level Reading 3/4/2008 APPROVED RLD JOB # 20085012 LOG OF BORING NO. 4 Page 1 of 1 ARCHITECT / ENGINEER MAV DEVELOPMENT SITE Rock Creek Dr. and Technology Pkwy. PROJECT Fort Collins, Colorado HARMONY TECHNOLOGY PARK, 3RD FILING SAMPLES TESTS DESCRIPTION 0 m pn W = W 0 U w W E- Z F Z ZF E O jEr 3 Q o- U W OU p wz DUw U Approx. Surface Elev.: 95.9 ft a o D M z Of m Qo Q xw o a D w o W SANDY LEAN CLAY Stiff to very Stiff, tan CLI 0.1 % 1 RS 12 18 14 114 5 500psf Color change reddish brown CL 2 RS 12 24 18 112 10 13.5 82.4 CLAYSTONE 15 Hard, brown to olive, iron staining 80.9 CH 3 RS 12 42 22 108 15 BOTTOM OF BORING i i s The stratification lines represent the appro)amate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft erracon BORING STARTED 2-27-08 I WL Q DRY WD 1 DRY AB BORING COMPLETED 2-27-08 WL g RIG CME 55 FOREMAN PDG WL Water Level Reading 3/4/2008 APPROVED RLD JOB # 20085012 LOG OF BORING NO. 5 Page 1 of 1 ARCHITECT / ENGINEER MAV DEVELOPMENT SITE Rock Creek Dr. and Technology Pkwy. PROJECT Fort Collins, Colorado HARMONY TECHNOLOGY PARK, 3RD FILING SAMPLES TESTS DESCRIPTION m o U U) w W U) F Xw I- Z H ZZ W 0 CL OJ Q OW OW c9 Approx. Surface Elev.: 95.2 ft o z W X inU O o a D v, r ` TOPSOIL SANDY LEAN CLAY Stiff to very stiff, reddish brown CL 1 RS 12 16 15 92 5 Color change tan CL 2 RS 12 26 24 100 io 15 * Gravel observed 80.2 15 CL 3 RS 12 36 16 116 The stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft Irerracon 1 BORING STARTED 2-27-08 7 DRY WD T DRY AB BORING COMPLETED 2-27-08 WL 7 RIG CME 55 FOREMAN PDGWELWLLWaterLevelReading3/4/2008 APPROVED RLD JOB # 20085012 LOG OF BORING NO. P6 Page 1 of 1 ARCHITECT / ENGINEER MAV DEVELOPMENT SITE Rock Creek Dr. and Technology Pkwy. PROJECT Fort Collins, Colorado HARMONY TECHNOLOGY PARK, 3RD FILING SAMPLES TESTS DESCRIPTION m w: LU U D w Z LL~ WS U w U cn Ww ZZ ff U c Approx. Surface Elev.: 96.5 ft CL o D z d U W p m F-Z U O C. Z) cn o w TOPSOIL SANDY LEAN CLAY Medium stiff to hard, reddish brown 6.8% CL 1 RS 12 50 15 111 150psf Color change tan CL 2 IRS 12 9 15 5— CL 3 BS 9 87.5 BOTTOM OF BORING The stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft erracon BORING STARTED 2-27-08 WL SZ DRY WD 1 DRY AB BORING COMPLETED 2-27-08 WL RIG CME 55 FOREMAN PDG WL Water Level Reading 3/4/2008 APPROVED RLD JOB # 20085012 APPENDIX B lrprr.o.irnn 8 7 6 5 4 3 0 z_ 2 1 040 1 2 3 4 5 100 1,000 10,000 PRESSURE, psf 0 Specimen Identification Classification Yd, pcf WC,% 8 7 6 5 4 3 0 z_ 2 1 1 2 3 4 5 100 1,000 10,000 PRESSURE, psf mO 0 Specimen Identification Classification Yd, pcf WC,% 3 9.OFt SANDY LEAN CLAY 108 20 8 7 6 5 4 3 0 z 2 co 09 1 2 3 4 5 100 1,000 10,000 PRESSURE, psf m0 0 Z Specimen Identification Classification Yd, pcf WC,% 4 4.Oft SANDY LEAN CLAY 114 14 11 1 8 7 6 5 4 3 a z 2 010 1 2 3 4 5 100 1,000 10,000 PRESSURE, psf m0 0 Specimen Identification Classification pcf WC,% 5 4.Oft SANDY LEAN CLAY 92 15 0 V 7 6 5 4 3 z 2 F- 1 1 2 3 PRESSURE, psf Specimen Identification Classification Yd, pcf WC,% P6 2.0 t SANDY LEAN CLAY 111 15 Notes: SWELL CONSOLIDATION TEST IrerraProject: HARMONY TECHNOLOGY PARK, 3RD FILING n Site: Rock Creek Dr. and Technology Pkwy. Fort Collins, Colorado Job #: 20085012 Date: 60 50 CL 00, CH P L A 40S T I C T 30 Y I N 20 D E X 10 CL-ML 0 0 20 lor ML EH 40 60 80 100 LIQUID LIMIT Specimen Identification LL PL PI Fines Classification 2 14.0ft 53 21 32 62 SANDY FAT CLAY(CH) 4 9.0ft 37 17 20 66 SANDY LEAN CLAY(CL) 5 4.0ft 32 18 14 69 SANDY LEAN CLAY P6 5.01ft 33 16 17 59 SANDY LEAN CLAY(CL) Irerracon ATTERBERG LIMITS RESULTS Project: HARMONY TECHNOLOGY PARK, 3RD FILING Site: Rock Creek Dr. and Technology Pkwy. Fort Collins, Colorado Job #: 20085012 GENERAL NOTES DRILLING & SAMPLING SYMBOLS: SS: Split Spoon - 1 3/8" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger ST: Thin -Walled Tube - 2" O.D., unless otherwise noted PA: Power Auger RS: Ring Sampler - 2.42" I.D., 3" O.D., unless otherwise noted HA: Hand Auger DB: Diamond Bit Coring - 4", N, B 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 3" O.D. ring samplers (RS) the penetration value is reported as the number of blows required to advance the sampler 12 inches using a 140- pound hammer failing 30 inches, reported as "blows per foot," 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 L2 SS1 RS) LS1 Relative RS1 SS) Blows/Ft. Blows/Ft. Consistency Blows/Ft. Blows/Ft. Density Blows/Ft. Blows/Ft. Consistency 3 2 Very Soft 0-6 3 Very Loose 30 20 Weathered 3-4 2-3 Soft 7-18 4-9 Loose 30-49 20-29 Firm 5-9 4-6 Medium Stiff 19-58 10-29 Medium Dense 50-89 30-49 Medium Hard 10-18 7-12 Stiff 59-98 30-49 Dense 90-119 50-79 Hard 19-42 13-26 Very Stiff 98 49 Very Dense 119 79 Very Hard 42 26 Hard RELATIVE PROPORTIONS OF SAND AND GRAVEL Descriptive Terms of Percent of Other Constituents Dry Weight GRAIN SIZE TERMINOLOGY 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 4 to #200 sieve (4.75mm to 0.075mm) Silt or Clay Passing #200 Sieve (0.075mm) RELATIVE PROPORTIONS OF FINES PLASTICITY DESCRIPTION Descriptive Terms of Percent of Other Constituents Dry Weight Term Plasticity Index Trace 5 Non -plastic 0 With 5-12 - Low 1-10 Modifiers 12 Medium 11-30 High 30+ Irerracan 11 0 UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests" Coarse Grained Soils Gravels Clean Gravels Cu >_ 4 and 1 5 Cc15 3E More than 50% retained More than 50% of coarse Less than 5% fines` fraction retained on Cu < 4 and/or 1 > Cc > 3E on No. 200 sieve No. 4 sieve Gravels with Fine RAF" I M Sands 50% or more of coarse fraction passes No. 4 sieve Fine - Grained Soils Slits and Clays 50% or more passes the Liquid limit less than 50 No. 200 sieve s ore Ines c assify as L or MH than 12% fines` Fines classify as CL or CH Clean Sands Cu t 6 and 1 5 Cc15 3E Group GW GP GM GC SW Less than 5% fines' Cu < 6 and/or 1 > Cc > 3E SP Sands with Fines Fines classify as ML or MH SM More than 12% fines° Fines classify as CL or CH SC inorganic PI > 7 and plots on or above "A" line' CL PI <4 or plots below "A" line' ML organic Liquid limit - oven driarl <0. 75 OL Soil Classification Group Name' Well graded gravelF Poorly graded gravelF Silty gravelF'-" Clayey gravelF-'-' Well graded sand' Poorly graded sand' Silty sand"," Clayey sand'-"' Lean clay"-" SiI1K'-" Organic clayK4"" Liquid limit - not Organic silfK4"° dried Silts and Clays inorganic PI plots on or above "A" line CH Fat clay"Am Liquid limit50ormorePIplots below "A" line MH Elastic silP`l-" organic Liquid limit - oven dried <075 OH Organic clayKc" P Liquid limit - not dried Organic siltKL-",o Soils Primarily organic matter, dark in color, and organic odor PT Peat Based on the material passing the 3-in. (75-mm) sieve e If field sample contained cobbles or boulders, or both, add Wth cobbles or boulders, or both" to group name. cGravels 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. 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 z FCu = Dso/ Dto Cc = D'0 Di' x Ds' F If soil contains z 15% sand, add "with sand" to group name. cif fines classiy as CL-ML, use dual symbol GC -GM, or SC-SM. 60 50 EL W 40 Z 30 U 5 20 a If fines are organic, add "with organic fines" to group name. If soil contains z 15% gravel, add "with gravel" to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. If soil contains 15 to 29% plus No. 200, add "with sand" or with gravel,' whichever is predominant. If soil contains 2 30% plus No. 200 predominantly sand, add sandy" to group name. MY soil contains >_ 30% plus No. 200, predominantly gravel, add gravelly" to group name. PI >_ 4 and plots on or above "A" line. PI < 4 or plots below "A" line. P PI plots on or above "A" line. oPl plots below "A" line For classification of fine-gralned soils and fine-grained fraction of coarse - grained soils Equation of " A" - line Horizontal at PI=4 to LL=25.5. then PI= 0.73 (LL•20) ap ok G O Equation of ' U" -line vertical at LL=1810 PI=7, Then PI= 0.9 (LL-8) MH or OH ML or OL 10 7 4 0 0 IV 19 4! Uu 40 5o 60 LIQUID LIMIT ( LL) 70 90 90 100 110 Irerracan ROCK CLASSIFICATION Based on ASTM C-294) Sedimentary Rocks Sedimentary rocks are stratified materials laid down by water or wind. The sediments may be composed of particles or pre-existing rocks derived by mechanical weathering, evaporation or bychemicalororganicorigin. The sediments are usually indurated by cementation or compaction. Chert Very fine-grained siliceous rock composed of micro -crystalline or cryptocrystal line quartz, chalcedony or opal. Chert is various colored, porous to dense, hard and has a conchoidal to splintery fracture. Claystone Fine-grained rock composed of or derived by erosion of silts and clays or any rock containing clay. Soft massive and may contain carbonate minerals. Conglomerate Rock consisting of a considerable amount of rounded gravel, sand and cobbles with or without interstitial or cementing material. The cementing or interstitial material may be quartz, opal, calcite, dolomite, clay, iron oxides or other materials. Dolomite A fine-grained carbonate rock consisting of the mineral dolomite [CaMg(CO3)21. May contain non -carbonate impurities such as quartz, chert, clay minerals, organic matter, gypsum and sulfides. Reacts with hydrochloric acid (HCL). Limestone A fine-grained carbonate rock consisting of the mineral calcite (CaCO3). May contain non -carbonate impurities such as quartz, chert, clay minerals, organic matter, gypsum and sulfides. Reacts with hydrochloric acid (HCL). Sandstone Rock consisting of particles of sand with or without interstitial and cementing materials. The cementing or interstitial material may be quartz, opal, calcite, dolomite, clay, iron oxides or other material. Shale Fine-grained rock composed of or derived by erosion of silts and clays or any rock containing clay. Shale is hard, platy, of fissile may be gray, black, reddish or green and may contain some carbonate minerals (calcareous shale). Siltstone Fine grained rock composed of or derived by erosion of silts or rock containing silt. Siltstones consist predominantly of silt sized particles (0.0625 to 0.002 mm in diameter) and are intermediate rocks between claystones and sandstones and may contain carbonate minerals. 1 LABORATORY TEST SIGNIFICANCE AND PURPOSE TEST SIGNIFICANCE PURPOSE California Bearing Used to evaluate the potential strength of subgrade soil, Pavement Thickness Ratio subbase, and base course material, including recycled Design materials for use in road and airfield pavements. Consolidation Used to develop an estimate of both the rate and amount of Foundation Design both differential and total settlement of a structure. Direct Shear Used to determine the consolidated drained shear strength Bearing Capacity, of soil or rock. Foundation Design, and Slope StabilityDryDensityUsedtodeterminethein -place density of natural, inorganic, Index Property Soilfine-grained soils. Behavior Expansion Used to measure the expansive potential of fine-grained Foundation and Slab soil and to provide a basis for swell potential classification. Design Gradation Used for the quantitative determination of the distribution o Soil Classification particle sizes in soil. Liquid & Plastic Limit, Used as an integral part of engineering classification Soil ClassificationPlasticityIndexsystemstocharacterizethefine-grained fraction of soils, and to specify the fine-grained fraction of construction materials. Permeability Used to determine the capacity of soil or rock to conduct a Groundwater Flow liquid or gas. Analysis pH Used to determine the degree of acidity or alkalinity of a Corrosion Potentialsoil. Resistivity Used to indicate the relative ability of a soil medium to carry Corrosion Potential electrical currents. R-Value Used to evaluate the potential strength of subgrade soil, Pavement Thickness subbase, and base course material, including recycled Design materials for use in road and airfield pavements. Soluble Sulfafe Used to determine the quantitative amount of soluble Corrosion Potential sulfates within a soil mass. Unconfined Compression To obtain the approximate compressive strength of soils that possess sufficient cohesion to permit testing in the Bearing Capacity unconfined state. Analysis for Foundations Index Property Soil Water Content Used to determine the quantitative amount of water in a soil mass. Behavior Irerracon y t, , a REPORT TERMINOLOGY Based on ASTM D653) Allowable Soil The recommended maximum contact stress developed at the interface of the foundation Bearing Capacity element and the supporting material. Alluvium Soil, the constituents of which have been transported in suspension by flowing water and subsequently deposited by sedimentation. Aggregate Base A layer of specified material placed on a subgrade or subbase usually beneath slabs orCoursepavements. Backfill A specified material placed and compacted in a confined area. Bedrock A natural aggregate of mineral grains connected by strong and permanent cohesive forces. Usually requires drilling, wedging, blasting or other methods of extraordinary force for excavation. Bench A horizontal surface in a sloped deposit. Caisson (Drilled A concrete foundation element cast in a circular excavation which may have an enlarged Pier or Shaft) base. Sometimes referred to as a cast -in -place pier or drilled shaft. Coefficient of A constant proportionality factor relating normal stress and the corresponding shear stress Friction at which sliding starts between the two surfaces. Colluvium Soil, the constituents of which have been deposited chiefly by gravity such as at the foot of a slope or cliff. Compaction The densification of a soil by means of mechanical manipulation Concrete Slab -on- A concrete surface layer cast directly upon a base, subbase or subgrade, and typically used Grade as a floor system. Differential Unequal settlement or heave between, or within foundation elements of structure. Movement Earth Pressure The pressure exerted by soil on any boundary such as a foundation wall. ESAL Equivalent Single Axle Load, a criteria used to convert traffic to a uniform standard, (18,000 pound axle loads). Engineered Fill Specified material placed and compacted to specified density and/or moisture conditions under observations of a representative of a geotechnical engineer. Equivalent Fluid A hypothetical fluid having a unit weight such that it will produce a pressure against a lateral support presumed to be equivalent to that produced by the actual soil. This simplified approach is valid only when deformation conditions are such that the pressure increases linearly with depth and the wall friction is neglected. Existing Fill (or Materials deposited throughout the action of man prior to exploration of the site. Man -Made Fill) Existing Grade The ground surface at the time of field exploration. Arerracon V . 11 or REPORT TERMINOLOGY Based on ASTM D653) Expansive The potential of a soil to expand (increase in volume) due to absorption of moisture. Potential Finished Grade The final grade created as a part of the project. Footing A portion of the foundation of a structure that transmits loads directly to the soil. Foundation The lower part of a structure that transmits the loads to the soil or bedrock. Frost Depth The depth at which the ground becomes frozen during the winter season. Grade Beam A foundation element or wall, typically constructed of reinforced concrete, used to span between other foundation elements such as drilled piers. Groundwater Subsurface water found in the zone of saturation of soils or within fractures in bedrock. Heave Upward movement. Lithologic The characteristics which describe the composition and texture of soil and rock by observation. Native Grade The naturally occurring ground surface. Native Soil Naturally occurring on -site soil, sometimes referred to as natural soil. Optimum Moisture The water content at which a soil can be compacted to a maximum dry unit weight by aContentgivencompactiveeffort. Perched Water Groundwater, usually of limited area maintained above a normal water elevation by the presence of an intervening relatively impervious continuous stratum. Scarify To mechanically loosen soil or break down existing soil structure. Settlement Downward movement. Skin Friction (Side The frictional resistance developed between soil and an element of the structure such as aShear) drilled pier. Soil (Earth) Sediments or other unconsolidated accumulations of solid particles produced by the physical and chemical disintegration of rocks, and which may or may not contain organic matter. Strain The change in length per unit of length in a given direction. Stress The force per unit area acting within a soil mass. Strip To remove from present location. Subbase A layer of specified material in a pavement system between the subgrade and base course. Subgrade The soil prepared and compacted to support a structure, slab or pavement system. Irerracon