Loading...
HomeMy WebLinkAbout20080558.tiff • • • GEOTECHNICAL ENGINEERING REPORT PROPOSED OFFICE/SHOP BUILDING & ISDS SOUTH SIDE OF WCR 22, APPROX. 3/4 MILES EAST OF US HWY 85 WELD COUNTY, COLORADO TERRACON PROJECT NO. 22065118 July 31, 2006 Prepared for: • Mr. Daniel Glantz Liquid Waste Management, Inc. 204 South Bowen Street Longmont, Colorado 80501 Prepared by: Terracon 1242 Bramwood Place, Suite 2 Longmont, Colorado 80501 Phone: 303-776-3921 Fax: 303-776-4041 • 2008-0558 lierracon • • lierracon Consulting Engineers &Scientists • July 31, 2006 1242 Bramwood Place Longmont,Colorado 80501 Phone 303.776.3921 Mr. Daniel Glantz Fax 303.776.4041 www.terracon.com Liquid Waste Management, Inc. 204 South Bowen Street Longmont, Colorado 80501 Re: Geotechnical Engineering Report Proposed Office/Shop Building & ISDS South Side of WCR 22, Approximately'A Miles East of US HWY 85 Weld County, Colorado Terracon Project No. 22065118 As requested, Terracon has completed a geotechnical engineering exploration for the proposed office/shop building and individual sewage disposal system (ISDS) to be located on the south side of WCR 22, approximately % miles east of US Highway 85. This study was performed in general accordance with our proposal number G2206125 dated July 14, 2006. The results of our engineering study, including the boring location diagram, test boring • records, laboratory test results and the geotechnical recommendations needed to aid in the design and construction of foundations and other earth connected phases of this project are attached. 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. If you have any questions concerning this report or any of our testing, observation, design and consulting services, please do not hesitate to contact us. Sincerely, Terracon r U Glenn D. Ohlsen, E.I.T. taiRar4,J.-ffa, P.E. Project Engineer Principal Copies to: Addressee (3) • Delivering Success for Clients and Employees Since 1965 More Than 80 Offices Nationwide • • Liquid Waste Management,Inc. lierracon Proposed Office/Shop Building 8ISDS • S.Side of WCR 22,Approx.3/4 Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 TABLE OF CONTENTS Page No. Letter of Transmittal ii INTRODUCTION 1 PROPOSED CONSTRUCTION 1 SITE EXPLORATION 2 ( Field Exploration 2 Laboratory Testing 3 SITE CONDITIONS 3 SUBSURFACE CONDITIONS 4 • Soil and Bedrock Conditions 4 Field and Laboratory Test Results 4 Groundwater Conditions 4 ENGINEERING ANALYSES AND RECOMMENDATIONS 5 Geotechnical Considerations 5 Spread Footing Foundation Recommendations 5 Pole Barn Foundation Recommendations 6 Floor Slab Design and Construction 7 Individual Sewage Disposal System (ISDS) Construction 8 Earthwork 8 General Considerations 8 Site Preparation 8 Subgrade Preparation 9 Fill Materials and Placement 10 Slopes 11 Excavation and Trench Construction 11 Underground Utility Systems 11 Corrosion Protection (Concrete) 11 Surface Drainage 12 GENERAL COMMENTS 12 • iii • • Liquid Waste Management,Inc. lrerracan Proposed Office/Shop Building&ISDS • S.Side of WCR 22,Approx.%Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 TABLE OF CONTENTS (Cont'd) APPENDIX A Boring Location Diagram Al Logs of Borings A2 to A6 Subsurface Diagram A7 APPENDIX B Swell-Consolidation Test Curves B1 to 810 Grain Size Distribution/Soil Classification B11 Percolation Test Results B12 APPENDIX C: General Notes: Drilling & Exploration Cl Unified Soil Classification C2 Rock Classification C3 1• • iv • • • GEOTECHNICAL ENGINEERING REPORT PROPOSED OFFICE/SHOP BUILDING & ISDS SOUTH SIDE OF WCR 22, APPROX. 3/< MILES EAST OF US HWY 85 WELD COUNTY, COLORADO TERRACON PROJECT NO. 22065118 July 31, 2006 INTRODUCTION This report contains the results of our geotechnical engineering exploration for the proposed office/shop building and individual sewage disposal system (ISDS) to be located on the south side of Weld County Road (WCR) 22, approximately 3% miles east of US Highway 85. The site is located in the Northeast 1/4 of Section 17, Township 2 North, Range 66 West of the 6th Principal Meridian in Weld County, Colorado. • The purpose of these services is to provide information and geotechnical engineering recommendations relative to: • Subsurface soil and bedrock conditions • Groundwater conditions • Foundation design and construction • Floor slab design and construction • Individual sewage disposal systems • General earthwork considerations • Site drainage considerations The recommendations contained in this report are based upon the results of field and laboratory testing, engineering analyses, experience with similar soil conditions and structures, and our understanding of the proposed project. PROPOSED CONSTRUCTION Based on information provided by a representative of Liquid Waste Management, Inc. (LWM), the proposed project will include the construction of an office/shop building with an attached • truck parking canopy at the subject site. The office/shop portion of the building will be a 1 • • Liquid Waste Management,Inc. lrermcon Proposed Office/Shop Building&ISDS S.Side of WCR 22,Approx.% Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 single-story, wood framed structure using slab-on-grade construction and will encompass about 8,700 square feet in plan view. The truck parking canopy will be a single-story wood framed structure as well and will have dimensions of about 24 feet by 100 feet. We also understand that pole barn construction is being considered for the project. Basement/below grade construction is not planned for the proposed building and we are not aware of any significant earth retaining structures for this project. Based on the size and type of construction planned, we anticipate comparatively light foundation loads. Other site development considerations will include the design and construction of an individual sewage disposal system (ISDS) in accordance with Weld County regulations. If foundation loads, or type of construction, varies from those outlined above, we should be contacted to confirm and/or modify our recommendations accordingly. SITE EXPLORATION The scope of the services performed for this project included site reconnaissance by a geotechnical engineer, a subsurface exploration program, laboratory testing, percolation testing and engineering analyses. • Field Exploration: A total of 5 test borings were drilled on July 21, 2006. The borings were drilled to depths of about 10 to 30 feet at the approximate locations shown on the Boring Location Diagram, Figure 1. Four borings were drilled within the footprint of the proposed office/shop building. One soil profile boring and 6 percolation test holes were drilled in the location of the proposed septic system. Percolation tests were conducted in general accordance with Weld County requirements. Borings were advanced with a truck- mounted drilling rig, utilizing 4-inch diameter solid stem augers. The borings were located in the field by measurements with a mechanical surveying wheel using property boundaries and/or existing site features as a reference. Right angles for locating the borings were estimated. Approximate ground surface elevations at each boring location were obtained by measurements with an engineer's level and rod from a temporary bench mark (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. A geotechnical engineer recorded lithologic logs of each boring during the drilling operations. At selected intervals, samples of the subsurface materials were taken by means of driving California barrel samplers. Penetration resistance measurements were obtained by driving the California barrel into the subsurface materials with a 140-pound hammer falling 30 inches. The penetration resistance value is a useful index in estimating • the consistency, relative density, or hardness of the materials encountered. In addition, 2 • • Liquid Waste Management,Inc. lierracon Proposed Office/Shop Building&ISDS • S.Side of WCR 22,Approx.3/4 Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 groundwater conditions were recorded in each boring at the time of site exploration and four days after completion of 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 time, the field descriptions were confirmed or modified as necessary and an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials. Boring logs were prepared and are presented in Appendix A. Laboratory tests were conducted on selected samples and are presented in Appendix B. The test results were used for the geotechnical engineering analyses, and the development of foundation and earthwork recommendations. Laboratory tests were performed in general accordance with applicable local standards or other accepted standards. • Selected soil/bedrock samples were tested for the following engineering properties: • Water Content • Swell-Consolidation Potential • Dry Unit Weight • Water Soluble Sulfate Content • Unconfined Compressive Strength • Atterberg Limits • Grain Size Distribution SITE CONDITIONS The site is located on the south side of Weld County Road 22, approximately % miles east of US Highway 85. The site is currently used for agricultural purposes, and is generally surrounded by agricultural land and sparse residential development. Oil/gas operations were observed in the immediate area surrounding the property. Vegetation consisted of a moderate to heavy growth of grasses/clover. The ground surface at the site was generally even with a slight downward slope to the north and northeast. A maximum difference in elevation of about 2% feet was measured across the location of our building test borings. I 3 • • Liquid Waste Management,Inc. lierracon Proposed Office/Shop Building 8 ISDS • S.Side of WCR 22,Approx.%.Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 SUBSURFACE CONDITIONS Soil and Bedrock Conditions: As presented on the Logs of Boring, a thin mantle of topsoil overlying sandy lean clays and/or silty sands were present to depths of about 3 to 6 feet below grade. Highly weathered bedrock was encountered below the clays/sands and extended to depths of about 6 to 9 feet, where it transitioned to firm to hard. The bedrock extended to the maximum depth of exploration. Please refer to the Logs of Boring for more comprehensive strata descriptions. Field and Laboratory Test Results: Field test results indicate that the clay soils are stiff to very stiff in consistency, while the sands are loose in relative density. The bedrock varies from weathered to hard in hardness. Laboratory test results indicate that subsoils at shallow depth have low swell potential. Swell-consolidation test results indicate that the weathered bedrock has low expansive potential, while the firm to hard bedrock has moderate expansive potential. Field test results indicate the soils in the area of the proposed septic system have poor percolation characteristics. Groundwater Conditions: Groundwater was only encountered in the Boring 1, immediately after drilling, at a depth of about 15 feet below existing grade. When checked four days later, groundwater was measured in all of the borings at depths of 3 to 16 feet. 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. Zones of perched and/or trapped groundwater, where not already present, may also occur at times in the subsurface soils overlying bedrock, on top of the bedrock surface or within permeable fractures in the bedrock materials. The location and amount of perched water is dependent upon several factors, including hydrologic conditions, type of site development, irrigation demands on or adjacent to the site, fluctuations in water features, seasonal and weather conditions. Fluctuations in groundwater levels can best be determined by implementation of a groundwater monitoring plan. Such a plan would include installation of groundwater monitoring wells, and periodic measurement of groundwater levels over a sufficient period of time. The possibility of groundwater fluctuations should be considered when developing design and construction plans for the project. • 4 • • • Liquid Waste Management,Inc. Terracon Proposed Office/Shop Building&ISDS • S.Side of WCR 22,Approx.Y.Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 ENGINEERING ANALYSES AND RECOMMENDATIONS Geotechnical Considerations: Based upon geotechnical conditions encountered in our test borings, the site appears suitable for construction. We believe that the primary geotechnical condition that will impact proposed construction on the site is the presence of shallow groundwater, generally encountered in the building area at depths of 3 to 4 feet below current site grades. Based upon the shallow groundwater, we recommend placing the floor slab at least five (5) feet above the level of the groundwater. This would require raising the site with approximately 2 to 4'/z feet of fill material. Fill placement should achieve a floor slab subgrade elevation of at least 110'/z feet, as shown on the attached Subsurface Diagram. Based upon our field and laboratory testing we anticipate that low swelling clays/sands and/or properly compacted/moisture-treated engineered fill will be encountered in the excavations. Considering the size and type of construction planned and the subsurface conditions encountered in our test borings, we recommend that the proposed structure be supported on spread footings. We understand that pole barn construction is also being considered by the client for support of the proposed structure, therefore we have also • evaluated the use of pole barn construction for the site. However, based upon the subsurface conditions encountered on the site, we feel that the use of a pole barn foundation will likely involve complications during construction associated with shallow groundwater and potentially caving sand soils. In addition, subsurface conditions encountered on the site may even preclude the use of this type of system for the proposed structure. Swell-consolidation tests performed on samples of the soil at or near the level of floor slabs indicate low swelling soils. Based upon the test data and our experience, we believe slabs- on-grade can be supported on the site materials, or properly moisture-treated and compacted fill, with a relatively low potential of excessive movement. The builder/owner should recognize that concrete floors constructed on low swelling soils could heave and crack to some degree if the underlying soils become wetted. Recommendations for the design and construction of foundations, floor slabs, foundation drainage, and individual sewage disposal systems are outlined in the following sections. Spread Footing Foundation Recommendations: We anticipate that low swelling clays/sands and/or properly compacted/moisture-treated engineered fill will be encountered in the excavation. Considering the size and type of construction planned and the subsurface conditions encountered in our test borings, we believe that the proposed structure can be • supported on spread footings. The completed foundation excavation should be observed by the geotechnical engineer, prior to the forming of footing construction, to confirm that 5 • • Liquid Waste Management,Inc. lierracon Proposed Office/Shop Building&ISDS • S.Side of WCR 22,Approx.Y.Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 satisfactory bearing materials are present and that subsurface conditions are consistent with those encountered in our test borings. Footings should bear on undisturbed natural soils or on tested and approved engineered fill and may be designed for a maximum soil bearing pressure of 1,500 pounds per square foot (psf.) The design bearing pressure applies to dead loads plus design live load conditions. Exterior footings and foundations in unheated areas must be protected from frost action. The normal depth of frost protection in this area is assumed to be around 30 inches. Comparatively soft clays and shallow groundwater were encountered on the site. To reduce the potential of "pumping" and softening of the foundation soils and the requirement for corrective work, we recommend the excavation be completed remotely with a track-hoe. Where soft soils are encountered at foundation bearing depth, they should be removed to a minimum depth determined by the geotechnical engineer and replaced with approved material. Footings should be proportioned to minimize differential foundation movement. Proportioning on the basis of relative constant dead-load pressure provides a means to reduce differential • movement between adjacent footings. Total movement of footings designed in accordance with the above criteria is estimated to be on the order of 1 inch. Proper drainage should be provided in the final design and during construction to reduce the potential of foundation movement. Foundations and walls should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. As mentioned above, the completed foundation excavation should be observed by the geotechnical engineer to confirm that satisfactory bearing materials are present and that subsurface conditions are consistent with those encountered in our test borings. If the soil conditions encountered differ from those presented in this report, supplemental recommendations will be required. Pole Barn Foundation Recommendations: We understand that a pole barn foundation is being considered by the client for support of the proposed structure. Based upon the subsurface conditions encountered in our borings, we feel that this type of foundation will likely involve complications during construction associated with shallow groundwater and potentially caving sand soils. The subsurface conditions,encountered may even preclude the use of pole barn construction on the site. In addition, moderately expansive claystone bedrock was encountered in our borings. Accordingly, pole barn foundations should be held at least 4 feet above the elevation of the firm bedrock, or at an elevation of approximately 106.0 feet. Where pole barn foundations are feasible, they may be designed • for a maximum soil bearing pressure of 1,500 pounds per square foot (psf.) The design 6 • • Liquid Waste Management,Inc. lierracon Proposed Office/Shop Building 8 ISDS • S.Side of WCR 22,Approx.V.Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 bearing pressure applies to dead loads plus design live load conditions. Foundations must be protected from frost action. The normal depth of frost protection in this area is assumed to be around 30 inches. To satisfy forces in the horizontal direction, foundations may be designed for lateral loads using a passive equivalent fluid pressure of 350 pounds per square foot per foot (psf/ft) for soils above the groundwater. The passive pressures outlined above are ultimate values. As such, appropriate factors of safety should be applied to these values. Floor Slab Design and Construction: Swell-consolidation tests performed on samples of the soils at or near the level of floor slabs typically indicated low swell potential when wetted. • Based on this data and on our experience, we believe slabs-on-grade can be supported on the site materials, or properly moisture-treated and compacted fill, with a relatively low potential of excessive movement. The builder/owner should recognize that concrete floor slabs constructed on low swelling soils could heave and crack to some degree when the subsoils become wetted. Slab heave on the order of 1 inch is possible and would be considered normal for soils like those found at this site. If slab movement can not be • accepted or must be reduced, we are available to discuss slab heave mitigation techniques, at your request. To reduce potential slab movements, carefully planned and maintained surface drainage will be important. We recommend the following precautions be observed for on-grade slabs. These precautions will not eliminate slab movement but they tend to reduce damage when movement occurs. Additional floor slab design and construction recommendations are as follows: • A minimum 2-inch void space should be constructed above, or below non- bearing partition walls placed on the floor slab. Special framing details and/or connections should be provided at doorways, stairwells and heating/air- conditioning units to allow vertical movement. • Positive separations and/or isolation joints should be provided between slabs and all foundations, columns or utility lines to allow independent movement. • Frequent control joints should be provided in slabs to control the location and extent of cracking in accordance with the American Concrete Institute (ACI). • 7 • • Liquid Waste Management,Inc. lferracon Proposed Shd &ISDS ,111 S.Side of WCROffice/22,ApproxopBuil.'ing Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 • Floor slabs should not be constructed on frozen subgrade. • 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. • Other design and construction considerations, as outlined in the ACI Design Manual, Section 302.1R are recommended. Individual Sewage Disposal System (ISDS) Construction: Percolation rates of 80 to 480 minutes per inch were obtained from testing conducted in percolation test holes P-1 through P-6. These values exceed the maximum allowable percolation rate of 60-minutes per inch acceptable for standard leach field construction as outlined by Weld County regulations. Accordingly, an engineered septic system is required for the site. • Earthwork: �y r V '\-' 14$t 3OV flip; flavii-- 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 fill, 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. Stripped materials consisting of vegetation and organic materials should be wasted from the site, or used to re-vegetate landscaped areas or exposed slopes after completion of grading operations. Exposed surfaces should be free of mounds and depressions that could prevent uniform compaction. 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 building structures. Exposed areas which will receive fill, once properly cleared, should be scarified to a minimum depth of eight inches, conditioned to near optimum moisture content, and • compacted. 8 • • • Liquid Waste Management,Inc. lierracon Proposed Office/Shop Building&ISDS • S.Side of WCR 22,Approx.%Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 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. Based upon the subsurface conditions encountered in our borings, low strength and high moisture content clays were found on the site. These materials are susceptible to disturbance and loss of strength under repeated excavation equipment wheel loads and unstable conditions could develop during earthwork operations. It should also be recognized that the overall stability of the subgrade may be affected by precipitation, excessive compaction water, repetitive construction traffic, or other factors. If unstable conditions develop, workability may be improved by scarifying and drying. Over- excavation of wet zones and replacement with granular materials may be necessary. Shallow groundwater was encountered on the site and should be anticipated for excavations approaching 2 feet. Pumping from sumps may be utilized to control water • within the excavations. Well points may be required for significant groundwater flow, or where excavations penetrate groundwater to a significant depth. Subgrade Preparation: Engineered fill will be used to raise the area of the proposed building pad. Prior to fill placement all existing vegetation, debris, or other deleterious materials should be stripped and removed from the proposed building area. The exposed subgrade soils should be scarified to a depth of nine (9) inches, moisture conditioned to within two (2) percent of the material's optimum moisture content and compacted to 95 • percent of the material's standard maximum dry density (ASTM D-698). Engineered fill should extend horizontally a minimum distance of 5 feet beyond the outside edge of perimeter footings. Areas of loose soils may be encountered at foundation bearing depth after excavation is completed for footings. When such conditions exist beneath planned footing areas, the subgrade soils should be compacted prior to placement of the foundation system. Subgrade soils beneath interior and exterior slabs, and beneath pavements should be • scarified, moisture conditioned and compacted to a minimum depth of ten inches. The moisture content and compaction of subgrade soils should be maintained until slab or pavement construction. S 9 • • Liquid Waste Management,Inc. Terracon Proposed Office/Shop Building&ISDS S.Side of WCR 22,Approx.'/.Miles E.of US Hwy 85 • Weld County,Colorado Terracon Project No.22065118 Fill Materials and Placement: Clean on-site soils or imported materials approved by the geotechnical engineer may be used as fill and/or backfill on the site. Imported soils should be evaluated and approved by the geotechnical engineer prior to delivery to the site. In general, imported materials having the following properties should be acceptable for use on the site. Percent finer by weight Gradation (ASTM C136) 6" 100 3" 70-100 No. 4 Sieve 50-100 No. 200 Sieve 65 (max) • Liquid Limit 35 (max) • Plasticity Index 15 (max) • 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. The engineered fill should be placed in level lifts of approximately nine (9) inches or less in loose thickness and should be compacted to at least 95 percent of the standard Proctor maximum dry density (ASTM D698). On-site or imported clay soils should be compacted within a moisture content range of 2 percent below to 2 percent above optimum. Imported granular soils should be compacted within a moisture range of 3 percent below to 2 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 to 10 feet. Fills less than 8 to 10 feet in depth, when placed and compacted as recommended in this report, will experience some self-weight induced compression/settlement, generally on the order of 1 inch. The amount and rate of settlement will be increased if water is introduced into the fill. In any event, sufficient time should be allowed for deeper fills to consolidate/compress prior to construction. If fill depths exceed about 8 to 10 feet, we should be contacted to determine whether modifications to the fill placement and compaction criteria are needed. • 10 • • Liquid Waste Management,Inc. lierracar1 Proposed Office/Shop Building&ISDS • S.Side of WCR 22,Approx.%.Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 Slopes: For permanent slopes in compacted fill or cut areas where saturation of the slopes will not occur, we recommend slopes of 3:1 (horizontal to vertical), or less to reduce erosion and maintenance problems. If saturated or steeper slopes and/or slopes over 8 to 10 feet in height are anticipated, or if structures or other surcharge loads will be located within a distance of the slope height from the crest of the slope, the slopes should be evaluated for stability on an individual basis. The face of all slopes should be compacted to the minimum specification for fill embankments. Alternately, fill slopes can be over- built and trimmed to compacted material. Slopes should be revegetated as soon as possible to reduce the potential for erosion problems. Surface drainage should be designed to direct water away from slope faces. Excavation and Trench Construction: Comparatively soft clays and shallow groundwater were encountered on the site. To reduce the potential of "pumping" and softening of the foundation soils and the requirement for corrective work, we recommend the excavation be completed remotely with a track-hoe. Where excavations penetrate the groundwater, temporary dewatering will be required during excavation, foundation work and backfilling operations for proper construction. Pumping from sumps • may be utilized to control water within the excavations. The individual contractor(s) is responsible for designing and constructing stable, temporary excavations, as required to maintain stability of the excavation sides and bottom as well as adjacent structures. 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. 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. Underground Utility Systems: Underground piping within or near the proposed structures should be designed and constructed so minor deviations in alignment do not result in breakage or distress. Utility knockouts in foundation walls should be oversized to accommodate differential movements. Corrosion Protection (Concrete): We measured the soluble sulfate concentrations for representative samples of the subsoils that will likely be in contact with structural concrete. The sulfate concentrations measured in the samples varied from 80 to 115 parts per million (ppm). Results of soluble sulfate testing indicate that Type I Portland cement is suitable for • project concrete. However, if there is no, or minimal cost differential, use of Type II Portland cement is recommended for additional sulfate resistance of construction concrete. 11 • • Liquid Waste Management,Inc. lrerracon Proposed OfficelShop Building 8 SOS • S.Side of WCR 22,Approx.% Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 Foundation concrete should be designed in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. Surface Drainage: Positive drainage should be provided during construction and maintained throughout the life of the proposed residence. Surface drainage will be important to the performance of foundations and concrete flatwork on this site. Infiltration of water into utility or foundation excavations must be prevented during and after construction. Planters and other surface features that could retain water in areas adjacent to the building or pavements should be sealed or eliminated. Backfill against exterior walls should be moistened at or near optimum and well compacted. In areas where sidewalks or paving do not immediately adjoin the structure, we recommend that protective slopes, where possible, be provided with a minimum grade of approximately 10 percent for at least 10 feet from perimeter walls. Backfill against footings, exterior walls, and in utility and sprinkler line trenches should be well compacted and free of construction debris to reduce the possibility of moisture infiltration. Downspouts, roof drains or scuppers should discharge into splash blocks or extensions when the ground surface beneath such features is not protected by exterior slabs or paving. • Sprinkler systems should not be installed or allowed to discharge within 5 feet of foundation walls. Landscaped irrigation adjacent to the foundation system should be minimized or eliminated. GENERAL COMMENTS 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 also should be retained to provide testing and observation during excavation, grading, foundation and construction phases of the project. The analysis and recommendations presented in this 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. • 12 • • Liquid Waste Management, Inc. lierracon Proposed Office/Shop Building&ISDS ,• S.Side of WCR 22,Approx.%Miles E.of US Hwy 85 Weld County,Colorado Terracon Project No.22065118 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 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 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 Terracon reviews the changes and either verifies or modifies the conclusions of this report in writing. i a• • 13 • WELD COUNTY ROAD 22 • TBM - NW CORNER CATTLE GUARD=- ! (ASSUMED ELEVATIONi100.0') 1!1 00 Q 3 l'3 N P-4 P-5 P-b PROPOSED TB-5 SEPTIC FIELD 9 a P-3 P-2 P-1 ( -3e)e,.4 ��- ' 4 TB-1 ra PROPOSED OFFICE/SHOP BUILDING .' TB-2 N TB-4 l TB-3 LEGEND• \ 100 m 0m APPROXIMATE LOCATION OF 9 TEST BORING DRILLED ON LIQUID WASTE MANAGEMENT, INC. JULY 21,2006 PROPOSED OFFICE/SHOP BLDG. 4 ISD5 WCR 22, APPROX. 3/4 MILES E. of HWY 55 APPROXIMATE LOCATION WELD COUNTY, COLORADO • OF PERCOLATION POLES FIGURE 1: BORING LOCATION DIAGRAM • TESTED JULY 25,2006 Project Manager GDO Project No. 22065115 Brain By. GDO 1 re r ra c o n Scale. I' = 100' R2 CEB 4-24-01 Checked By. E,JP 1242 Branwood Place Bate' 1/26/06 DIAGRAM IS FOR GENERAL LOCATION ONLY,AND IS R1 CEB 5-19-99 Longmont,Colorado 80501 1 of I i NOT INTENDED FOR COt'ISTRUCTION PURPOSES R0 CHS 4-22-98 Approved By. EJF 303-776-3921 Sheet No, LOG OF TEST BORING NO. TB-1 Page 1 of 1 CLIENT Liquid Waste Management, Inc. • SITE WCR 22,Approx. 3/4 Miles E. of HWY 85 PROJECT Weld County,Colorado Proposed Office/Shop Building & ISDS SAMPLES TESTS U o ZO o tJ Lilt) co w DESCRIPTION 2 F ZN a�a ¢ z - 5, _ Cr) W W c Zw 2 Ze'z USo aa f CO > W o WI- Ow -Upp a U d U z3 HZ Y. U�ty t_12(1, - CC Approx. Surface Elev.: 106.5 ft W D D F W a Z <O o a D o W to ° '‘I' 't 0.5 VEGETATIVE SOIL LAYER 106 - // \SAND and CLAY soil with vegetation and I root penetration. SILTY SAND Y SM CB 9/12 16 108 4 brown, grey brown, beige, loose, fine to 102.5 medium grained, contains SANDY CLAY to \CLAYEY SAND interbeds. I 5 6 LEAN CLAY with SAND 100.5 - CL CB 16/12 16 113 +0.9/500 \brown, olive brown, beige, stiff to very stiff, / slightly calcareous. HIGHLY WEATHERED CLAYSTONE — 9 brown, grey, rust/orange brown, "Clay-Like" 97.5 — \properties, stiff to very stiff. / 10 - CB 30/12 22 103 CLAYSTONE _ - grey, olive, rust/orange brown, black, firm — ' to medium hard, slightly lignitic, contains = SANDSTONE/SILTSTONE interbeds. ii 0 15 CB 50/11 16 120 14400 - - CB 37/12 18 108 9140 20 -25 81.5 - CB 39/12 22 103 10500 Bottom of Test Boring 25 F 0 0 z 0 0 The stratification lines represent the approximate boundary lines m between soil and rock types: in-situ,the transition may be gradual. WATER LEVEL OBSERVATIONS,ft BORING STARTED 7-21-06 Ill WL Z 15 7/21/06 ? 3 7/25/06 1r err acon RIG BORING COMPLETED 7-21-06 d Deidriich D-55 FOREMAN EB o WL ? Y w rr WL APPROVED ESW JOB# 22065118 0 0 • LOG OF TEST BORING NO. TB-2 Page 1 of 1 CLIENT Liquid Waste Management, Inc. • SITE WCR 22,Approx. 3/4 Miles E. of HWY 85 PROJECT Weld County, Colorado Proposed Office/Shop Building & ISDS i SAMPLES TESTS J J o _ Z N ° ° DESCRIPTION m >2p � = z N J (-22 K Wft CC C Z ~ LL W U 2 = U W > F K W Q a Z U p a U co w °U z3 aZ > UAW WjO a Approx. Surface Elev.: 107.5 ft a 3 D F CC aa..WO 3° o a D°W Ct r-f° °0.5 VEGETATIVE SOIL LAYER 107 (SAND and CLAY soil with vegetation and I — /; root penetration. SM CB 6/12 17 101 SILTY SAND / brown, grey brown, tan, loose, fine to medium grained, contains SANDY CLAY to _ f 55 CLAYEY SAND interbeds. 102 5 HIGHLY WEATHERED CLAYSTONE CB 18/12 20 108 +2.0/500 brown, beige, grey, rust/orange brown, I 8 "Clay-Like" properties, stiff. 995 1 CLAYSTONE — grey, olive, rust/orange brown, black,firm — CB 31/12 18 111 +2.0/1000 to medium hard, slightly lignitic, contains io - - SANDSTONE/SILTSTONE interbeds. — I• — CB 37/12 20 109 +2.5/1000 15 1 _ 20 875 — CB 50/12 20 107 +2.0/2000 20 Bottom of Test Boring i izz l- 0 0 z 0 a CC CC Ill I- -3 The stratification lines represent the approximate boundary lines m between soil and rock types: in-situ, the transition may be gradual. WATER LEVEL OBSERVATIONS,ft BORING STARTED 7-21-06 WL Q Dry AB 7/21 16 7/25/06 1 [err acon RIG BORINGF 7 21 Deidri h D-55 EFOREMAN EB I o WL APPROVED ESW JOB# 22065118, 0% LOG OF TEST BORING NO. TB-3 Pagel of 1 CLIENT • Liquid Waste Management, Inc. • SITE WCR 22,Approx.3/4 Miles E. of HWY 85 PROJECT Weld County,Colorado Proposed Office/Shop Building & ISDS SAMPLES TESTS O 0 d OZ in eH o> a OW DESCRIPTION 2 > F Z1- Zoy o z' > K w ac z ~ LLw0 OCR 0 m > t� KW Z Oaz 'L. H to w O W N w t- W Ell a• lr a. 0 m >- W z o <O m V ZO� 5=o o Approx. Surface Elev.: 109.0 ft o 7 Z o Cl.s 3 0 o a D 0 CO CO N ,' 0.5 VEGETATIVE SOIL LAYER 108.5 - (SAND and CLAY soil with vegetation and I root penetration. SANDY LEAN CLAY — CL CB 7/12 18 111 +0.2/250 brown,tan, beige, medium stiff. Y - 5 104 — HIGHLY WEATHERED CLAYSTONE 5 — CB 11/12 23 102 brown, grey, rust/orange brown,white, 7 \'Clay-Like" properties, stiff. / 102 CLAYSTONE - grey, olive brown, rust/orange brown, - - - black, firm to hard, slightly lignitic, contains — CB 32/12 20 106 _ SANDSTONE/SILTSTONE interbeds. 10 ill 15 CB 45/12 17 112 - CB 44/12 20 108 12070 20 i - - - - 25 - 30 7y CB 50/6 15 114 19740 30 o Bottom of Test Boring c3 0 U C KK F ft 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 7-21-06 0 WL Q Dry AB 7/21 = 3.5 7/25/06 BORING COMPLETED 7-21-06 o WL Y Y 1 terracon RIG Deidrich D-55 FOREMAN EB f;L APPROVED ESW JOB# 22065118 • • LOG OF TEST BORING NO. TB-4 Page 1 of 1 CLIENT Liquid Waste Management, Inc. • SITE WCR 22,Approx. 3/4 Miles E. of HWY 85 PROJECT . Weld County, Colorado Proposed Office/Shop Building & ISDS SAMPLES TESTS J J E Z w S O C7 O o r 0> 6 (n W o DESCRIPTION z >- p $ zN z h o a cc w rc Z Z EwoZWz U= I- Co a] W O Wm WI- D O0-w -.J Sr? ' o Approx. Surface Elev.: 108.5 ft o CO D F CC a 3 3 0 o a Dom >,„O " 0.5 VEGETATIVE SOIL LAYER Lea — \SAND and CLAY soil with vegetation and I _ root penetration. ' ./. SANDY LEAN CLAY CL CB 13/12 18 110 +1.0/250 3 5 brown, tan, beige, stiff, contains 105 I \CLAYSTONE fragments. — HIGHLY WEATHERED CLAYSTONE 5 , brown, grey, rust/orange brown, beige, — CB 24/12 18 111 +1.3/500 "Clay-Like"properties, very stiff. — t 8 100.5 CLAYSTONE — - grey, olive brown, rust/orange brown, — CB 50/12 15 116 +1.4/1000 black, medium hard to hard, slightly lignitic, 10 contains SANDSTONE/SILTSTONE - interbeds. — ¢• - CB 50/11 20 108 +2.3/1500 5 20 88,5 - CB 46/12 20 109 16670 20 Bottom of Test Boring Co F O CD z 0 a CC ff t- The stratification lines represent the approximate boundary lines to between soil and rock types: in-situ,the transition may be gradual. '° WATER LEVEL OBSERVATIONS, ft BORING STARTED 7-21-06 51 WL Q Dry AB 7/21 1 4 7/25/06 llerraccin RIGBO Deidrich D-55 NG EFFOREMAN 7-21-06 51 EB o WL APPROVED ESW JOB# 22065118, m% • • -- 1 LOG OF TEST BORING NO. TB-5 Page 1 of 1 CLIENT Liquid Waste Management, Inc. _ • SITE WCR 22,Approx. 3/4 Miles E. of HWY 85 PROJECT Weld County, Colorado Proposed Office/Shop Building & ISDS SAMPLES TESTS J C7 O c o h- C> n m W DESCRIPTION i F ZN o�a S x } w IY w Q E z F- LLwC7 U1-\= v) W > tZ ix Z ZKZ JSo m D 0- JU d 0 2 a O z3 WI- >- UO2w wL� 0 Approx. Surface Elev.: 102.5 ft o Co D I- a a B 3 0 o a D 0 W CO "'a 0.5 VEGETATIVE SOIL LAYER 142 102 \ANDt and LAYon. soil with vegetation and f — 3 LEAN CLAY with SAND 3' 99.5 \brown, dark brown, beige, contains SILTY 1 - CB 13/12 27 93 SAND interbeds. , HIGHLY WEATHERED CLAYSTONE 5 6 olive brown, grey, rust/orange brown, ><,y96.5 — white "Cla -Like" ro rties stiff. 4 CB 26/12 18 112 CLAYSTONE (in 715 jjy-te" _ grey, olive brown, rust/orange brown, — black,firm to medium hard, slightly lignitic, — 10 contains SANDSTONE/SILTSTONE 92.5 - CB 50/12 22 105 \interbeds. / 10 Bottom of Test Boring ei (I • • cg Yo-A-5 0 0 U Q K WX The stratification lines represent the approximate boundary lines m between soil and rock types: in-situ,the transition may be gradual. WATER LEVEL OBSERVATIONS, ft BORING STARTED 7-21-06 5' WL 2 Dry AB 7/21 = 7 7/25/06 ir erracon RIG BORING EEBF7-21-06 o WL Y Deidrich D-55 FOREMAN w m`WL APPROVED ESW JOB# 220651180 115 115 i-• RECOMMENDED FLOOR SLAB 5UBGRADE ELEVATION BECAUSE OF HIGH GROUNDWATER SITE ELEV. • 1105 rest 110 - _ _ - / - - - - - , - -110 TB-4 TB-3 5 FOOT OFFSET (MN) TB-2 TB-1 105 / _. 111 MEASURED GROUNDWATER LEVEL JULY 25,2006 (APPROX.ELEV.=1O55 feet) ._ 100 -- --- 100 c O co 95 ._ - - 95 m W 90 85 85 • a e 0 80 80 O z 0 UQ 75 75 0 LTD Distance Along Baseline, ft. SUBSURFACE DIAGRAM 1 inerracon Project: Proposed Office/Shop Building & ISDS Site: WCR 22, Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado Job#: 22065118 O Date: 7-31-06 • 10 8 I �- 6 4 _ J w u, 2- - -- ♦ Z O -2 a J UJ Z -6 --f L_ -8 -- _ , L - -10 l 0.1 1 10 100 APPLIED PRESSURE,ksf Specimen Identification Classification 7d, pcf WC,% • TB-1 5.0ft Lean Clay with Sand(CL) 113 16 0 0 Notes: Water Added to Sample at 500 psf. ce 0 = SWELUCONSOLEDATION TEST • Project: Proposed Office/Shop Building & 1SDS y 1 re rracon Site: WCR 22,Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado o Job#: 22065118 U Date: 7-26-06 • • 10 - _• 8 6 J 4 JJ' co 2 o • Z o -2 H Q D J O Z -4 U '• 6 -8 -10 0.1 1 10 100 APPLIED PRESSURE, ksf ( e Specimen Identification Classification Yd, pcf WC,% • TB-2 5.0ft Claystone 108 20 0 z z Notes: Water Added to Sample at 500 psf. SWELL/CONSOLIDATION TEST • a Project: Proposed Office/Shop Building & ISDS 1��rra�on Site: WCR 22, Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado a Job #: 22065118 U o Date: 7-27-06 i • 10 • • 8 . . 6 4 I -- - •--- V; 2 0•— • O -2 _.J o -4 -6 -8 -10 0.1 1 10 100 APPLIED PRESSURE,ksf Specimen Identification Classification Yd, pcf WC,% • TB-2 9.0ft Claystone 111 18 ' o Notes: Water Added to Sample at 1,000 psf. a SWELL/CONSOLIDATION TEST a N Project: Proposed Office/Shop Building & iSDS y 1 Tarr acon Site: WCR 22,Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado Job#: 22065118 0 Date: 7-26-06 • • 10 • 8 6 4 2 z \ • 0 2 z 4 0 U i• -6 -8 -10 0.1 1 10 100 APPLIED PRESSURE, ksf Specimen Identification Classification rd, pcf WC,% • • TB-2 14.0ft Claystone 109 20 O 0 Notes: Water Added to Sample at 1,000 psf. cc U' SWELL/CONSOLIDATION TEST • a N e Project: Proposed Office/Shop Building & ISDS 1 'erraeon Site: WCR 22, Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado o Job#: 22065118 U Date: 7-26-06 • • 10 • 8 6 4 I1sJI 2 o J z O -2 F Q J O 0) 0z -4 4 1 -6 -8 -10 0.1 1 10 100 APPLIED PRESSURE,ksf Specimen Identification Classification Yd, pcf WC,% • TB-2 19.0ft Claystone 107 20 Notes: Water Added to Sample at 2,000 psf. c( 0 L6 46 SWELUCONSOLIDATION TEST • N Project: Proposed Office/Shop Building & ISDS 11 err acon Site: WCR 22, Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado O Job#: 22065118 0 o Date: 7-26-06 • • 10 • 8 6 J 4 J ww 2 o fT 1 N 0z 10 100 APPLIED PRESSURE, ksf Specimen Identification Classification Yd, pcf WC,% • TB-3 2.0ft SANDY LEAN CLAY(CL) 111 18 0 Notes: Water Added to Sample at 250 psf. = SWELL/CONSOLIDATION TEST • a N Project: Proposed Office/Shop Building & ISDS 1 ierr acon Site: WCR 22, Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado o Job #: 22065118 U Date: 7-26-06 • • 10 • 8 6 4 W L vl 2 o • z O -2 O J co co z -4 U • 6 -8 -10 0.1 1 10 100 APPLIED PRESSURE, ksf Specimen Identification Classification Yd, pcf WC,% • TB-4 2.0ft Sandy Lean Clay(CL) 110 18 z Notes: Water Added to Sample at 250 psf. eff . SWELUCONSOLIDATION TEST N Project: Proposed Office/Shop Building & ISDS 1 ferr�con Site WCR 22, Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado o Job #: 22065118 Date: 7-26-06 • • 10 ,0 8 6 } J-J 4 CO 2— • o -2 Q O OZ -4 • -6 -8 1 - I -10_ - - -- 0.1 1 10 100 APPLIED PRESSURE,ksf i Specimen Identification Classification 7d, pcf WC,% • TB-4 5.0ft Claystone 111 18 Notes: Water Added to Sample at 500 psf. • c!,00 SWELL/CONSOLIDATION TEST Project: Proposed Office/Shop Building & ISDS 1 err acon Site: WCR 22, Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado o Job#: 22065118 U Date: 7-26-06 0 i 101 I 0 8 . 6 4 2 _ . 0 co-- - U l 1 i I• -6- I - - �- i -8 -- _ __• i -10 , . - _._ I 0.1 1 10 100 APPLIED PRESSURE, ksf Specimen Identification Classification Yd, pcf WC,% sv j • TB-4 9.0ft Claystone 116 15 s O Notes: Water Added to Sample at 1,000 psf. a. m R SWELUCONSOLIDATION TEST 0 Project: Proposed Office/Shop Building & ISDS 1 ferr�con Site: WCR 22, Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado 0 Job#: 22065118 U o Date: 7-26-06 • • 10 ;w 8 i J 4 -- - m 2r : N: . o -2 l ._— i a O I 0 o -4 I r • 6 -8 -10 0.1 1 10 100 APPLIED PRESSURE,ksf Specimen Identification Classification Yd, pcf WC,% E • TB-4 14.0ft Claystone 108 20 0 c 0 0 cc Notes: Water Added to Sample at 1,500 psf. cc N a I z SWELL/CONSOLIDATION TEST 0 Project: Proposed Office/Shop Building & ISDS c°6°1' lrerracon Site: WCR 22, Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado 0 Job #: 22065118 0 Date: 7-26-06 U.S.SIEVE OPENING•HES I U.S.SIEVE NUMBERS • I HYDROMETER 6 4 3 2 1.5 1 3/4 1/2 3 6 6101416 20 30 40 5060 100140200 100 95 • so 65 80 75 70 H 65 w 60 >- 55 m m Le 50 z LL H 45 z ' in 40 w a I 35 - I 30 - - 25 PO - I 15 • 10 -- - 5 , . 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL SAND SILT OR CLAY coarse I fine coarse I medium I fine Specimen Identification Classification LL PL PI Cc Cu • TB-2 9.0ft Claystone 59 17 42 ' T TB-3 2.0ft SANDY LEAN CLAY(CL) 34 13 21 Specimen Identification D100 D60 D30 D10 %Gravel %Sand %Silt I %Clay 1• • TB-2 9.0ft 12.7 0.7 1.8 97.4 o m TB-3 2.0ft 12.7 0.2 37.2 62.6 a cc c CD • 7, GRAIN SIZE DISTRIBUTION/SOIL CLASSIFICATION N Project: Proposed Office/Shop Building & ISDS 1 brracon Site: WCR 22, Approx. 3/4 Miles E. of HWY 85 Weld County, Colorado re Job#: 22065118 c o Date: 7-26-06 • • PERCOLATION TEST RESULTS Client/Project: Liquid Waste Management Inc. /Proposed Office/Shop Bldg. Project No.: 22065118 Location: WCR 22,Approx. 3/4 miles East of US Hwy 85 Tester: KPL Legal Description: NE 1/4 Section 17, Township 2 North, Range 66 West Test Date: 7/25/2006 Soil Description: Lean Clay with Sand (CL) P - 1 P - 2 P - 3 Depth:40" Diameter:8" Depth:40" Diameter:9" Depth: 37" Diameter:8" Change in Change Percolation Change in Change Percolation Change in Change Percolation Reading Height in Time Rate Reading Height in Time Rate Reading Height in Time Rate 22 5/16 - - - 24 5/16 - - - 20 3/16 - - - 2215/16 5/8 30 48 24 3/8 1/16 30 480 20 1/4 1/16 30 480 23 3/8 7/16 30 69 24 7/16 1/16 30 480 20 5/16 1/16 30 480 23 3/4 3/8 30 80 24 1/2 1/16 30 480 20 3/8 1/16 30 480 Hole Perc. Rate: min./in. Hole Perc. Rate: min./in. Hole Perc. Rate: min./in. P - 4 P - 5 P - 6 Depth: 39" Diameter:9" Depth: 39" Diameter:9" Depth: 36" Diameter: 9" Change in Change Percolation Change in Change Percolation Change in Change Percolation Reading Height in Time Rate Reading Height in Time Rate Reading Height in Time Rate 21 7/8 - - - 22 3/4 - - - 2113/16 - - - 21 7/8 0 30 - 22 3/4 0 30 - 22 7/16 5/8 30 48 22 1/8 30 240 23 1/4 30 120 2215/16 1/2 30 60 22 1/16 1/16 30 480 23 1/8 1/8 30 240 23 3/16 1/4 30 120 gap° � C -) • - ( V) 91-Et ' Hole Perc. Rate: min./in. Hole Perc. Rate: min./in. Holee Permin./in. 1242 Bramwood Place, Longmont, Colorado 80501 liarracon I • • 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 CB: California Barrel-1.92"I.D.,2.5"O.D.,unless otherwise noted RB: Rock Bit BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary The number of blows required to advance a standard 2-inch O.D. split-spoon sampler(SS)the last 12 inches of the total 18-inch penetration with a 140-pound hammer falling 30 inches is considered the "Standard Penetration" or "N-value". For 2.5" O.D. California Barrel samplers (CB) the penetration value is reported as the number of blows required to advance the sampler 12 i inches using a 140-pound hammer falling 30 inches, reported as "blows per inch" and is not considered equivalent to the "Standard Penetration"or"N-value". WATER LEVEL MEASUREMENT SYMBOLS: WL: Water Level WS: While Sampling WCI: Wet Cave in WD: While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB: After Boring ACR: After Casing Removal Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other times and other locations across the site could vary. In pervious soils,the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels.may not be possible with only short-term observations. DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils have more than 50%of their dry weight retained on a#200 sieve;their principal descriptors are: boulders, cobbles,gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a#200 sieve;they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency. I. FINE-GRAINED SOILS COARSE-GRAINED SOILS BEDROCK CLB) JSS) LC.M I §1 Relative (CBI (SS) Blows/Ft. Blows/Ft. Consistency Blows/Ft. Blows/Ft. Density Blows/Ft. Blows/Ft. Consistency <3 <2 Very Soft 0-5 <3 Very Loose <24 <20 Weathered 3-4 2-3 Soft 6-14 4-9 Loose 24-35 20-29 Firm 5-7 4-6 Medium Stiff 15-46 10-29 Medium Dense 36-60 30-49 Medium Hard 8-15 7-12 Stiff 47-78 30-49 Dense 61-96 50-79 Hard 16-32 13-26 Very Stiff >78 >49 Very Dense >96 >79 Very Hard >32 >26 Hard RELATIVE PROPORTIONS OF SAND AND GRAIN SIZE TERMINOLOGY GRAVEL Descriptive Terms of Percent of Major Component Other Constituents Dry Weight 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+ • • , llerracon UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests" Soil Classification Group Symbol Group Names Coarse Grained Soils Gravels Clean Gravels Cu≥4 and 1 ≤Co≤3E GW Well graded gravel' More than 50%retained More than 50%of coarse Less than 5%foes` Cu<4 and/or 1 >Cc>3E GP Poorly graded gravel` fraction retained on on No.200 sieve No.4 sieve Gravels with Fines Fines classify as ML or MH GM Silty graver'°" More than 12%fines` Fines classify as CL or CH GC Clayey 9ravel`°" Sands Clean Sands Cu≥6 and 1≤Cc≤3E SW Well graded sand' 50%or more of coarse Less than 5%foes° Cu<6 and/or 1 >Cc>35 SP Poorly graded sand' fraction passes No.4 sieve Sands with Fines Fines classify as ML or MH SM Silty sands"' More than 12%fines° Fines classify as CL or CH SC Clayey sand°" I Fine-Grained Soils Silts and Clays Inorganic PI>7 and plots on or above"A"line' CL Lean clay" 50%or more passes the Liquid limit less than 50 PI<4 or plots below"A"line' ML Silt" No.200 sieve Organic Liquid limit-oven Organic Nalco*" dried. <0.75 OL Liquid limit-not Organic siltl`M° dried Silts and Clays Inorganic PI plots on or above"A"line CH Fat clay" Liquid limit 50 or more PI plots below"A"line MH Elastic silt".`"" Organic Liquid limit-oven dried Organic clay"`s`° <0.75 OH Liquid limit-not dried Organic silt"""'" Highly organic soils Primarily organic matter,dark in color,and organic odor PT Peat • • ABased on the material passing the 3-in.(75-mm)sieve Hif fines are organic,add"with organic fines"to group name. °If field sample contained cobbles or boulders, or both,add"with cobbles I If soil contains≥ 15%gravel, add"with gravel"to group name. or boulders, or both"to group name. "If Atterberg limits plot in shaded area,soil is a CL-ML,silty clay. cGravels with 5 to 12%fines require dual symbols: GW-GM well graded Klf soil contains 15 to 29%plus No.200,add'with sand"or"with gravel with silt,GW-GC well graded gravel with clay,GP-GM poorly gravel,"whichever is predominant. graded gravel with silt,GP-GC poorly graded gravel with clay. L If soil contains≥30%plus No.200 predominantly sand,add °Sands with 5 to 12%fines require dual symbols: SW-SM well graded "sandy"to group name. sand with silt,SW-SC well graded sand with clay,SP-SM poorly graded sand with silt,SP-SC poorly graded sand with clay M If soil contains≥30%plus No.200,predominantly gravel, add"gravelly"to group name. z FCu= Deo/D10 Cc= (Dao) Ni PI≥4 and plots on or above"A"line. Dio x Cho ° PI<4 or plots below"A"line. Flt soil contains≥15%sand,add"with sand"to group name. PPI plots on or above"A"line. olf fines classify as CL-ML,use dual symbol GC-GM, or SC-SM. 0 PI plots below"A"line. . 60 I I I For classification of fine-grained soils and fine-grained fraction 50 —of coarse-grained soils X00 , vve Equation of"A"-line eS, a Horizontal at PI=4 to LL=25.5. X 40 — then PI=0.73(LL-20) i O� W boa p Equation of"U"-line ? Vertical at LL=16 to PI=7, C I ->-• 30 — then PI=0.9(LL-5) i a ' Ot' i 0) ...„CO 20 ° I o_ I' MH or OH 10 /iii I i • 7[ ' �a _. h _ ML or OL m . I I i I . 0 0 10 16 20 30 40 50 60 70 80 90 100 110 LIQUID LIMIT(LL) lierra con _ • ! 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 of pre-existing rocks derived by mechanical weathering, evaporation or by chemical or organic origin. The sediments are usually indurated by cementation or compaction. Chert Very fine-grained siliceous rock composed of micro-crystalline or crypto- crystalline 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; gray, black, brown, reddish or green 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 j. (CO3)21. May contain noncarbonate 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 noncarbonate 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, or 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, may be gray, black, brown, reddish or green and may contain carbonate minerals. lierracon Hello