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Home My WebLink About20110513.tiff CTLITHOMPSON THOMPSON • INCORPORATED • GEOTECHNICAL INVESTIGATION CONQUEST OIL FACILITY 61619 WELD COUNTY ROAD 77 WELD COUNTY, COLORADO Prepared For: CGRS, INC. Box 1489 1301 Academy Court Fort Collins, Colorado 80522 Attention: Mr. Craig Mulica Project Manager- Geologist Project No. FC03645.025-125 • October 27, 2010 2011-0513 351 Linden Street I Suite 140 I Fort Collins, Colorado 80524 I Phone:970-206-9455 I Fax:970-206-9441 TABLE OF CONTENTS SCOPE 1 SUMMARY OF CONCLUSIONS 1 SITE CONDITIONS 2 PROPOSED CONSTRUCTION 2 INVESTIGATION 3 SUBSURFACE CONDITIONS 3 Seismicity 4 OVERALL SOIL DISCUSSION 4 SOIL MODIFICATION 6 Subexcavation 6 General Excavation 6 Fill Placement 7 • FOUNDATIONS 8 Drilled Piers Bottomed in Bedrock 8 Footings 10 Reinforced Concrete Mat • R10 PUMP VAULT 11 FLOOR SYSTEMS 12 PAVEMENTS FOR UNLOADING AREA 13 Subgrade and Pavement Materials and Construction 14 Pavement Maintenance 14 WATER-SOLUBLE SULFATES 15 SURFACE DRAINAGE 15 LIMITATIONS 16 FIGURE 1 -LOCATIONS OF EXPLORATORY BORINGS FIGURE 2- EXAMPLE LATERAL EARTH PRESSURE DISTRIBUTIONS APPENDIX A-FIELD BOREHOLE LOGS APPENDIX B-RESULTS OF LABORATORY TESTING • APPENDIX C-SAMPLE SITE GRADING SPECIFICATIONS APPENDIX D- PAVEMENT CONSTRUCTION RECOMMENDATIONS APPENDIX E- PAVEMENT MAINTENANCE PROGRAM • SCOPE This report presents the results of our Geotechnical Investigation for the proposed improvements associated with the Conquest Oil Facility project located at 61619 Weld County Road 77 near Grover, Colorado in Weld County. The purpose of the investigation was to evaluate the subsurface conditions and provide foundation recommendations and geotechnical design criteria for the project. The report was prepared from data developed during field exploration, laboratory testing, engineering analysis, and experience with similar conditions. The report includes a description of subsurface conditions found in exploratory borings observed by representatives of CGRS, Inc. and discussions of site development as influenced by geotechnical considerations. Our opinions and recommendations regarding design criteria and construction details for foundations, floor systems, slabs-on-grade, lateral earth loads, pavements, and drainage are provided. If the proposed construction • changes, we should be requested to review our recommendations contained in this report to determine if they apply to the new proposed construction. Our opinions are summarized in the following paragraphs. More complete descriptions of the subsurface conditions, results of our field and laboratory investigations and our opinions, conclusions and recommendations are included in the subsequent sections of this report. SUMMARY OF CONCLUSIONS 1. Representatives of CGRS, Inc. observed drilling and collected samples during your field investigation portion of the project. A representative of CGRS delivered field borehole logs as well as soil samples collected during drilling to our office for laboratory testing. 2. Based on the CGRS boring logs provided, soils generally consisted of 4 to 12 feet of silty sand and well graded sand over clay. Laboratory tests indicate similar conditions with the exception of SB-2 at 2 feet which classified as a clay soil. We believe the clay logged below the upper sands is a medium hard to hard claystone. Ground water was not encountered during your investigation. • 3. Moderately to highly expansive clay / claystone was encountered at this site. We recommend the proposed pre-fabricated metal building be COLORADO GROUNDWATER RESOURCE SERVICES,INC. 1 CONQUEST OIL FACILITY AT 61619 WCR 77 CTL I T PROJECT NO.FC03S45.025-125 constructed on a drilled pier foundation. As an alternative, a shallow foundation system either consisting of a footing foundation or a reinforced mat foundation can be considered provided the subgrade is moisture conditioned. We believe the proposed reinforced containment structure to support the above ground storage tanks can be constructed as a reinforced mat foundation. The sump pit should also be constructed as a reinforced concrete mat foundation. We recommend a void under the central portion of the sump pit foundation to concentrate deadloads. Footing foundations and reinforced mat foundations should be constructed over a subexcavation. A more complete discussion is provided in the OVERALL SOIL DISCUSSION section of this report. 4. If footing foundations are selected for the pre-fabricated metal building, we believe a structural floor should be considered if movement cannot be tolerated. As an alternative, a slab-on-grade floor over a subexcavation can be considered. Some movement of slab-on-grade floors should be anticipated. We expect movements will be on the order of 1 inch or less. 5. The borings drilled in the proposed concrete unloading pad and AST containment pad indicated subgrade soils encountered consisted of silty sand. One sample classified as AASHTO A-7-6 soil, with a group index of 21 and showed a swell potential of 4.3 percent during swell- • consolidation testing when wetted under a confining pressure of 150 pounds per square foot (psf). For the unloading pad, we recommend 7 inches of portland cement concrete over a 2-foot subexcavation. SITE CONDITIONS The site is located at 61619 Weld County Road 77 in Weld County, Colorado approximately six miles northwest of Grover (Figure 1). The vacant lot is relatively flat and slopes gently down to the east. Ground cover in the area of the proposed improvements consisted of natural grasses and weeds. Several structures are located south of the proposed construction site including grain silos and a residence with several out buildings including a garage, well house, and lean-to shed. PROPOSED CONSTRUCTION We understand the proposed construction will consist of a pre-fabricated, single- story metal building with no below grade area, a reinforced AST concrete containment structure to support above ground storage tank(s), and a concrete surfaced unloading • pad to provide a hard-surfaced pavement for loading and unloading activities at the site. The unloading pad will have a drain that will flow to a sump pit. We understand the COLORADO GROUNDWATER RESOURCE SERVICES,INC. 2 CONQUEST OIL FACILITY AT 61619 WCR 77 Cal T PROJECT NO.FC03645.025-125 • sump pit will be approximately 10-foot by 15-foot and 10 feet deep. We have assumed very little site grading will be needed to construct the proposed improvements. We also understand the above ground storage tank(s) will be heavily loaded for the majority of the life of the containment structure. INVESTIGATION CGRS investigated subsurface conditions at the site by drilling four borings to depths of 25 to 40 feet below the existing ground surface. The approximate locations of the borings are shown on Figure 1. The CGRS field representative observed drilling, logged the soils found in the borings and obtained samples. Summary logs of the borings, including results of field penetration resistance tests, are presented in Appendix A. A representative of CGRS delivered samples obtained during drilling to our • laboratory where they were visually examined by the geotechnical engineer for this project. Laboratory testing Included moisture content, dry density, Atterberg limits, gradation, swell-consolidation and water-soluble sulfate tests. Results of laboratory tests are presented in Appendix B and summarized on Table B-I. SUBSURFACE CONDITIONS Based on your boring logs, soils generally consisted of 4 to 12 feet of silty sand and well graded sand over clay. Laboratory tests indicate similar conditions with the exception of SB-2 at 2 feet which classified as a clay soil. Overall, we believe the clay logged below the upper sands is a medium hard to hard claystone. Ground water was not encountered during your investigation. Further description of the subsurface conditions is presented on your boring logs and in our laboratory testing. • COLORADO GROUNDWATER RESOURCE SERVICES,INC. 3 CONQUEST OIL FACILITY AT 81619 WCR 77 CTL IT PROJECT NO.FC03645.025-125 Seismicity This area, like most of central Colorado, is subject to a low degree of seismic risk. As in most areas of recognized low seismicity, the record of the past earthquake activity in Colorado is somewhat incomplete. According to the 2009 International Building Code and the subsurface conditions encountered in our borings, this site classifies as a Site Class D. Only minor damage to relatively new, properly designed and built buildings would be expected. Wind loads, not seismic considerations, typically govern dynamic structural design in this area. A Remi Survey can be used to determine the shear wave velocities at the site. A survey of this type may result in a lower seismic site class (Site Class C). However, in our experience this is unlikely. OVERALL SOIL DISCUSSION • Laboratory testing at this site indicates the soils exhibit the potential for swell related soil movement significant enough to cause distress to the planned structures. The methods employed to deal with this potential need to be evaluated with the value of the planned construction and the risk of structure failure. The improvements necessary to eliminate the potential for structure movement may not be appropriate for the needs of the facility. However, increasing swell protection measures will also reduce potential maintenance costs. At a minimum, soil modification below planned improvements should be considered, and depending on how sensitive the structures are, or the contents of the structures, further considerations may be warranted. Foundations - Deep foundations, such as drilled piers, will provide the best performance for structures at this site. An alternative with a higher risk of movement is to construct shallow footing foundations on modified, moisture conditioned soils. Footings bearing on native soils are not appropriate for this site and will likely prove troublesome. Recommendations for foundation construction are provided in the FOUNDATIONS section of this report. • COLORADO GROUNDWATER RESOURCE SERVICES,INC. 4 CONQUEST OIL FACILITY AT 61819 WCR 77 CTL T PROJECT NO.FC03845.025-125 • Floors and Pavements - Floor slabs and pavement areas are very sensitive to potential swell movement of soils. Options for interior floors are to either construct them as a structural floor supported on the foundations, or construct them on modified, moisture conditioned soil. Neither slabs nor paved areas should be constructed on un-modified soils. Recommendations for floors are provided in the FLOOR SYSTEMS section of this report. Recommendations for pavements are provided in the PAVEMENTS section of this report. Mat Systems -Another option to consider is to construct the buildings and floor slabs as a single, reinforced concrete mat supported on modified, moisture conditioned soil. This system may provide better performance for the slab and reduce differential movements between the structure and the floor slab, which can solve issues at door openings in the building. Recommendations for mat foundation systems are provided in the FOUNDATIONS section of this report. • Pump Vault—The pump vault will be relatively deep below grade compared to the other planned structures. Normally we would recommend constructing the vault on a foundation similar to the other structures. If the building is to be supported on a pier foundation, the pump vault should also. However, if the vault is not connected to other structures and the plumbing connections are sufficiently flexible to allow some vault movement, supporting the vault on shallow foundations would be appropriate. This could consist of either providing soil modification (moisture conditioning) below the planned vault base, or providing void below the center portion of the vault floor to concentrate the vault loads on the perimeter portions of the vault, thereby providing an increased dead load. The soil modification option will increase the depth of the excavation and should be considered in the construction methods. Pump vault foundation recommendations are provided in the FOUNDATIONS section of this report. Recommendations for floor void are presented in the FLOOR SYSTEMS section of this report. Additional discussion and recommendations are provided in the PUMP VAULT section of this report. • COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 5 CTL T PROJECT NO.FC03645.025-125 • SOIL MODIFICATION Subexcavation Moderately to highly expansive clay/claystone was encountered at this site. We recommend subexcavation below footing foundations, mat foundations, slabs-on-grade, and the sump pit. If footing foundations are used for the proposed building, we recommend subexcavating 3 feet below footings. If a slab-on-grade floor is constructed for the proposed building, the subexcavation below the slab should extend to the same elevation as the subexcavation for footing foundations. Where mat foundations are planned and below the unloading pad and sump pit, we recommend subexcavating to a depth of 2 feet. Subexcavation should consist of removing the soils to the recommended depth, scarifying the base of the excavation to a depth of about 8 inches, moisture conditioning and compacting the fill to desired grades. Excavations can be filled with on-site soils and bedrock, moisture conditioned and compacted as described • in the Fill Placement section of this report. General Excavation - The materials found in our borings can be excavated using conventional heavy- duty excavation equipment. Excavations should be sloped or shored to meet local, State and Federal safety regulations. Based on our investigation and OSHA standards, we believe the clay soils classify as Type B soils and the sand soils classify as Type C soils. Type B soils require a maximum slope inclination of 1:1 (horizontal:vertical) in dry conditions. Type C soils require a maximum slope inclination of 1.5:1 (horizontal:vertical) in dry conditions. Excavation slopes specified by OSHA are dependent upon types of soil and groundwater conditions encountered. The contractors "competent person" should identify the soils encountered in the excavation and refer to OSHA standards to determine appropriate slopes. Stockpiles of soils, equipment, or other items should not be placed within a horizontal distance equal to one-half the excavation depth, from the edge of excavation. No deep excavations that would require shoring are anticipated at this time. If plans change, we should be contacted to provide • recommendations. COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 6 CTL I T PROJECT NO.FC03645.025-125 Water and sewer lines are often constructed beneath pavement areas. Compaction of trench backfill can have a significant effect on the life and serviceability of pavements. We recommend trench backfill be moisture conditioned and compacted as described above. Placement and compaction of fill and backfill should be observed and tested by a representative of our firm during construction. Fill Placement Fill material placed as backfill around the structures should be a low permeability clay material. The existing on-site soils are suitable for re-use as fill material provided debris or deleterious organic materials are removed. If import material is required, we recommend importing a low permeability clayey material. Import fill should contain greater than 60 percent silt and clay sized particles (percent passing No. 200 sieve). Areas to receive fill should be scarified, moisture-conditioned and compacted to • at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). The properties of the fill will affect the performance of foundations, slabs-on-grade, and pavements. Sand soils used as fill should be moistened to within 2 percent of optimum moisture content. Clay fill soils should be moistened to between optimum and 3 percent above optimum moisture content. The fill should be moisture-conditioned, placed in thin, loose lifts (8 inches or less) and compacted as described above. Placement and compaction of fill should be observed and tested by a representative of our firm during construction. Fill placement and compaction activities should not be conducted when the fill material or subgrade is frozen. Site grading in areas of landscaping where no future improvements are planned can be placed at a dry density of at least 90 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). Example site grading specifications are presented in Appendix C. • COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 7 CTL!T PROJECT NO.FC03645.025-125 • FOUNDATIONS Moderately to highly expansive clay/claystone was encountered at this site. We recommend the proposed pre-fabricated metal building be constructed on a drilled pier foundation. As an alternative, a shallow foundation system consisting of either footings or a reinforced mat constructed can be considered. We believe the proposed reinforced containment structure to support the above ground storage tanks can be constructed as a reinforced mat foundation. The sump pit should also be constructed as a reinforced concrete mat foundation. We recommend the soils below the vault be moisture conditioned or void be included under the central portion of the sump pit foundation to concentrate deadloads to the perimeter of the structure. Footing foundations and reinforced mat foundations should be constructed over a subexcavation. Subexcavation recommendations are presented in the SOIL MODIFICATION section of this report. Design and construction criteria for drilled pier, footing and reinforced concrete • mat foundations are provided below. These criteria were developed from analysis of field and laboratory data and our experience. The recommended foundation alternatives . can be used provided all design and construction criteria presented in this report are followed. The builder and structural engineer should also consider design and construction details established by the structural warrantor (if any) that may impose additional foundation design and installation requirements. Drilled Piers Bottomed in Bedrock 1. Piers should be designed with a minimum embedment of 17 feet into the clay/claystone. 2. Piers should be designed for a maximum allowable end pressure of 12,500 psf and an allowable skin friction of 1,250 psf for the portion of the pier in bedrock. Skin friction should be neglected for the portion of the pier in overburden soils, weathered bedrock, or within 3 feet of grade beams. 3. We recommend designing the piers for a minimum deadload pressure of 10,000 psf based on the pier cross-sectional area. If the minimum deadload pressure cannot be achieved, the minimum bedrock penetration • and minimum length should be increased to compensate for the deficiency, using the allowable skin friction value discussed above. COLORADO GROUNDWATER RESOURCE SERVICES.INC. CONQUEST OIL FACILITY AT 81819 WCR T7 8 CTL T PROJECT NO.FC03645.025-125 • 4. Axial tension loads can be resisted using a skin friction value of 1,250 psf for the portion of pier in bedrock. 5. Piers should be designed with a length/diameter ratio less than 30. 6. Shear rings should be installed in the lower portion of piers. We recommend provision of shear rings that extend about 3 inches beyond the pier shaft to increase the load transfer through skin friction. These shear rings should be spaced about 2 feet on-center for the bottom 8 feet of pier in bedrock. 7. Pier drilling should produce shafts with relatively undisturbed bedrock exposed. Excessive remolding and caking of bedrock cuttings on pier walls should be removed. 8. Piers should be reinforced their full length and the reinforcement should extend into grade beams or foundation walls. A minimum steel-to-pier cross-sectional area ratio of 0.005 using Grade 60 steel is recommended. More reinforcement may be required by structural considerations. 9. An 8-inch continuous void should be constructed beneath grade beams, between piers, to concentrate structural deadload on the piers. • 10. Grade beams should be well reinforced. The structural engineer should design the reinforcement. 11. Piers should have a center-to-center spacing of at least three pier diameters when designing for vertical loading conditions, or they should be designed as a group. Piers aligned in the direction of lateral forces should have a center-to-center spacing of at least six pier diameters. Reductions for closely spaced piers are discussed in the following section. 12. Concrete should have a slump of 6 inches (+/- 1 inch). Concrete should be ready and placed in the pier holes immediately after the holes are drilled, cleaned, observed and the reinforcing steel is set. 13. No ground water was encountered in our borings. If ground water is encountered during drilling, pump or tremie pipe placement of concrete may be required for proper cleaning, dewatering and placement of concrete during pier installation. Concrete should not be placed by free fall in pier holes containing more than 3 inches of water. 14. Some movement of the drilled pier foundation is anticipated to mobilize the skin friction. We estimate this movement to be on the order of 1/4 to 1/2 inch. Differential movement may be equal to the total movement. • 15. We should be retained to observe the installation of the drilled pier foundations to confirm the piers are bottomed in the proper bearing strata and to observe the contractor's installation procedures. COLORADO GROUNDWATER RESOURCE SERVICES.INC. CONQUEST OIL FACILITY AT 61619 WCR 77 9 CTL-,T PROJECT NO.FC03645.025-125 • Footings 1. Footings should be constructed over a subexcavation as described in the SOIL MODIFICATION section of this report. Where soil is loosened during excavation, it should be removed and replaced with on-site soils compacted following the criteria in the Fill Placement section of this report. 2. Footings constructed on the properly compacted fill can be designed for a net allowable soil pressure of 3,000 psf and a minimum dead load of 1000 psf. The soil pressure can be increased 33 percent for transient loads such as wind or seismic loads. 3. Footings should have a minimum width of at least 16 inches. Foundations for isolated columns should have minimum dimensions of 24 inches by 24 inches. Larger sizes may be required depending on loads and the structural system used. 4. The soils beneath footing pads can be assigned an ultimate coefficient of friction of 0.55 to resist lateral loads. The ability of grade beams, or footing backfill to resist lateral loads can be calculated using a passive • equivalent fluid pressure of 350 pcf. This assumes the backfill is densely compacted and will not be removed. Backfill should be placed and compacted to the criteria in the Fill Placement section of the report. 5. Exterior footings should be protected from frost action. We believe 30 inches of frost cover is appropriate for this site. 6. Foundation walls and grade beams should be well reinforced both top and bottom. 7. We should be retained to observe the completed footing excavations to confirm that the subsurface conditions are similar to those found in your borings. Reinforced Concrete Mat 1. Reinforce concrete mat foundations should be constructed over a subexcavation as described in the SOIL MODIFICATION section of this report. The reinforced concrete mat foundation should be designed for a net allowable soil pressure of 3,000 psf. The soil pressure can be increased 33 percent for transient loads such as wind or seismic loads. 2. Reinforced slabs are typically designed using a modulus of subgrade recommend use of a modulus of 75 pounds per square inch per inch of deflection (pci). • 3. The soils beneath footing pads can be assigned an ultimate coefficient of friction of 0.4 to resist lateral loads. The ability of grade beams, or footing COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 10 CTL'i T PROJECT NO.FC03645.025.125 • backfill to resist lateral loads can be calculated using a passive equivalent fluid pressure of 350 pcf. This assumes the backfill is densely compacted and will not be removed. Backfill should be placed and compacted to the criteria in the Fill Placement section of the report. A moist unit weight of 120 pcf can be assumed for natural soils and compacted fill. These values are considered ultimate values and appropriate factors of safety should be used. Typically, a factor of safety of 1.5 is used for sliding and 1.6 for lateral earth pressure. 4. The edges of the mats should be thickened or turned down for structural strength. 5. Materials beneath the mat foundation should be protected from frost action. We believe 30 inches of frost cover is appropriate for this site. 6. We should be retained to observe the completed excavations for mats to confirm that the subsurface conditions are similar to those found in your borings. PUMP VAULT • The sump pit will be constructed below grade at this site. Below grade structures should be designed to resist lateral earth pressures. The amount of pressure on the wall is a function of the type of backfill, drainage conditions, slope of the backfill surface, and the rotation of the wall. The walls will be essentially rigid and unable to rotate to mobilize the strength of the backfill soils. Therefore, they should be designed for the 'at rest" earth pressure condition. A graphical presentation of lateral pressure conditions is presented as Figure 2. For "active" conditions, an equivalent fluid pressure of 45 pcf should be used. For"at rest' conditions, an equivalent fluid pressure of 60 pcf should be used. For"passive" conditions, an equivalent fluid pressure of 350 pcf should be used. All backfill should be well compacted, as discussed above. The recommended equivalent fluid density values do not include allowances for hydrostatic pressures or surcharge loads. They do not include a factor of safety. Effects of sloping backfill, vehicle loads and other surcharges should be taken into account. No ground water was encountered during our investigation. For this condition and the planned construction, perimeter drains are not usually necessary. We can • provide foundation drain recommendations if requested. COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 11 CTL I T PROJECT NO.FC03645.025-125 'illl FLOOR SYSTEMS If a reinforced concrete mat foundation is selected for the pre-fabricated metal building, the floor will be integral with the foundation system. If a footing foundation is selected for the pre-fabricated metal building, we believe a structural floor should be used due to the expansive clay / claystone encountered at this site. If the owner can accept some risk of movement, a slab-on-grade floor constructed over a subexcavation is appropriate. Recommendations for subexcavation are presented in the SOIL MODIFICATION section of this report. If a structurally supported floor is selected, we recommend a minimum void between the ground surface and the underside of the floor system of 6 inches. The minimum void should be constructed below beams and utilities that penetrate the floor. The floor may be cast over void form. Void form should be chosen to break down quickly after the slab is placed. We recommend against the use of wax or plastic-coated • void boxes. If the owner elects to use slab-on-grade construction and accepts the risk of movement and associated damage, we recommend the following precautions for slab- on-grade construction at this site. These precautions can help reduce, but not eliminate damage or distress due to slab movement. 1. Slabs should be separated from exterior walls and interior bearing members with a slip joint that allows free vertical movement of the slabs. This can reduce cracking if some movement of the slab occurs. 2. Slabs should be placed directly on exposed soils or properly moisture conditioned, compacted fill. The 2009 International Building Code (IBC) requires a vapor retarder be placed between the base course or subgrade soils and the concrete slab-on-grade floor. The merits of installation of a vapor retarder below floor slabs depend on the sensitivity of floor coverings and building use to moisture. A properly installed vapor retarder (10 mil minimum) is more beneficial below concrete slab-on- grade floors where floor coverings, painted floor surfaces or products stored on the floor will be sensitive to moisture. The vapor retarder is most effective when concrete is placed directly on top of it, rather than • placing a sand or gravel leveling course between the vapor retarder and the floor slab. The placement of concrete on the vapor retarder may increase the risk of shrinkage cracking and curling. Use of concrete with COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 12 CTL I T PROJECT NO.FC03645.025-125 • reduced shrinkage characteristics including minimized water content, maximized coarse aggregate content, and reasonably low slump will reduce the risk of shrinkage cracking and curling. Considerations and recommendations for the installation of vapor retarders below concrete slabs are outlined in Section 3.2.3 of the 2006 report of American Concrete Institute (ACI) Committee 302, "Guide for Concrete Floor and Slab Construction (ACI 302.R1-04)". 3. If slab-bearing partitions are used, they should be designed and constructed to allow for slab movement. At least a 1.5-inch void should be maintained below or above the partitions. If the "Float" is provided at the top of partitions, the connection between interior, slab-supported partitions and exterior, foundation supported walls should be detailed to allow differential movement. 4. Underslab plumbing should be eliminated where feasible. Where such plumbing is unavoidable it should be thoroughly pressure tested for leaks prior to slab construction and be provided with flexible couplings. Pressurized water supply lines should be brought above the floors as quickly as possible. 5. Plumbing and utilities that pass through the slabs should be isolated from • the slabs and constructed with flexible couplings. Where water and gas lines are connected to furnaces or heaters, the lines should be constructed with sufficient flexibility to allow for movement. 6. HVAC equipment supported on the slab should be provided with a collapsible connection between the furnace and the ductwork, with allowance for at least 1.5 inches of vertical movement. 7. The American Concrete Institute (ACI) recommends frequent control joints be provided in slabs to reduce problems associated with shrinkage cracking and curling. To reduce curling, the concrete mix should have a high aggregate content and a low slump. If desired, a shrinkage compensating admixture could be added to the concrete to reduce the risk of shrinkage cracking. We can perform a mix design or assist the design team in selecting a pre-existing mix. PAVEMENTS FOR UNLOADING AREA One boring was drilled for the proposed unloading area. Laboratory tests on selected samples indicated the subgrade will likely consist of sandy clay that generally classifies as AASHTO category A-7-6 with a group index of 21. If imported fill is needed to achieve desired grades, we have assumed it will be soils with similar characteristics. • These soils are considered to have poor subgrade characteristics. We recommend COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 13 CTL T PROJECT NO.FC03645.025-125 subexcavating 2 feet below the proposed pavement as described in the SOIL MODIFICATION section of this report. We used the group index approach to estimate the support characteristics of the anticipated subgrade in our design calculations. We understand heavily loaded trucks and unique materials handling equipment will be trafficking the unloading pavement. Our designs are based on the AASHTO design method and our experience. For design calculations, we assumed an Equivalent Single-Axel Load (ESAL) of 365,000 would be appropriate for this site. We should be contacted if our assumptions for traffic loading conditions for the unloading area are not accurate to review our pavement thickness design. Using the criteria discussed above we recommend the minimum pavement sections provided in Table B. TABLE B RECOMMENDED PAVEMENT SECTIONS • . m= ant Unloading Area. 7.0" Subarade and Pavement Materials and Construction The design of a pavement system is as much a function of the quality of the paving materials and construction as the support characteristics of the subgrade. Moisture treatment criteria and additional criteria for materials and construction requirements are presented in Appendix D of this report. Pavement Maintenance Routine maintenance, such as sealing and repair of cracks, is necessary to achieve the long-term life of a pavement system. We recommend a preventive maintenance program be developed and followed for all pavement systems to assure the design life can be realized. Choosing to defer maintenance usually results in • accelerated deterioration leading to higher future maintenance costs, and/or repair. A recommended maintenance program is outlined in Appendix E. COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 14 CTL T PROJECT NO.FC03645.025-125 • Excavation of completed pavement for utility construction or repair can destroy the integrity of the pavement and result in a severe decrease in serviceability. To restore the pavement top original serviceability, careful backfill compaction before repaving is necessary. WATER-SOLUBLE SULFATES Concrete that comes into contact with soils can be subject to sulfate attack. We measured a water-soluble sulfate concentration of 0.02 in one sample from this site. Sulfate concentrations less than 0.1 percent indicate Class 0 exposure to sulfate attack for concrete that comes into contact with the soils, according to the American Concrete Institute (ACI). For this level of sulfate concentration, ACI indicates any type of cement can be used for concrete that comes into contact with the soils and/or bedrock. In our experience, superficial damage may occur to the exposed surfaces of highly permeable concrete, even though sulfate levels are relatively low. To control this risk and to resist • freeze-thaw deterioration, the water-to-cementitious material ratio should not exceed 0.50 for concrete in contact with soils that are likely to stay moist due to surface drainage or high water tables. Concrete should be air entrained. SURFACE DRAINAGE Performance of pavements, flatwork and foundations are influenced by changes in subgrade moisture conditions. Carefully planned and maintained surface grading can reduce the risk of wetting of the foundation soils and pavement subgrade. We recommend raising elevations, where feasible, to allow for a greater slope away from the proposed improvements. In addition, we recommend the following precautions be observed during and maintained after the completion of the proposed construction: 1. Wetting or drying of the open foundation excavations should be avoided. 2. Positive drainage should be provided away from foundations. We • recommend a minimum slope of at least 5 percent in the first 10 feet away from the foundations in landscaped areas, where possible. COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 15 CTL I T PROJECT NO.FC03645.025-125 • Pavements and sidewalks adjacent to the building should be sloped for positive drainage away from the building. Water should not be allowed to pond on pavements. 3. Backfill around foundations should be moisture treated and compacted as described in the Fill Placement section of this report. 4. Roof drains should be directed away from the structures. Downspout extensions and splash blocks should be provided at discharge points. Where downspouts discharge onto pavement and aggregate-surfaced parking areas, the pavement or aggregate-surfaced parking areas should be sloped away from the structures. 5. Landscaping should be carefully designed to minimize irrigation. Irrigation should not be located within 5 feet of the foundations. Sprinklers should not discharge within 5 feet of foundations. Irrigation should be limited to the minimum amount sufficient to maintain vegetation; application of more water will increase likelihood of slab and foundation movements. 6. Impervious plastic membranes should not be used to cover the ground surface immediately surrounding the structures. These membranes tend • to trap moisture and prevent normal evaporation from occurring. Geotextile fabrics can be used to limit weed growth and allow for evaporation. LIMITATIONS Although the borings were spaced to obtain a reasonably accurate picture of subsurface conditions, variations not indicated in the borings are always possible. We should be retained to observe pier installation and footing and reinforce mat foundation excavations to confirm soils are similar to those found in our borings. We should also be retained to observe and test placement and compaction of fill, backfill, subgrade, and other fills during construction. This report was prepared from data developed during your field exploration, laboratory testing, engineering analysis and experience with similar conditions. The recommendations contained in this report were based upon our understanding of the planned construction. If plans change or differ from the assumptions presented herein, we should be contacted to review our recommendations. • COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61819 WCR 77 16 CTL.T PROJECT NO.FC03845.025-125 • We believe this investigation was conducted in a manner consistent with that level of skill and care ordinarily used by members of the profession currently practicing under similar conditions in the locality of this project. No warranty, express or implied, is made. If we can be of further service in discussing the contents of this report or in the analysis of the structures and pavement from the geotechnical point of view, please contact the undersigned. CTL I THOMPSON, INC. by: �P� REG/si, CA ccS m• • cc Spencer Sch am, El .B. "Chip" Leadbett I;•PE Project Engineer Division Manager G- • • • COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 17 CTL T PROJECT NO.FC03645.025-125 o APPROXIMATE SITE3 ; 81819 WCR 77 SCALE: 1'=100' 0' 50' 100' WCR 122 Gina LEGEND: VICINITY MAP SB-1 INDICATES APPROXIMATE LDCO TTY,CDLDRADO) SCALE • LOCATION OF EXPLORATORY BORING 1 SB-1 05° • r Proposed Building • ,e Proposed Drain r ` l .• SB-4 �•''•,SB-3 4.1‘,:;"-.-4.e.; SB 2 with Sump Pit:.: ., i; � Proposed Proposed K.......... Unloading Pad AST Containment Locations of Exploratory Borings COLORADO GROUNDWATER RESOURCE SERVICES,INC. FIGURE 1 CONQUEST OIL FACILITY AT 61619 WCR 77 CTL I T PROJECT NO.FC038C5.025-125 WALL EARTH • TYPE PRESSURE !(II P = 'VA • H H = HEIGHT OF WALL (FT) H P = LATERAL PRESSURE (PSF) A = ACTIVE HYDROSTATIC UNIT WEIGHT (PCF) P CANTILEVER WALL (Active Condition) P = 0.6 * 1A • H H H = HEIGHT OF WALL (FT) P = LATERAL PRESSURE (PSF) P yA = ACTIVE HYDROSTATIC UNIT WEIGHT (PCF) �F BRACED OR TIE-BACK EXCAVATION • P = Y • H H H = HEIGHT OF WALL (FT) P = LATERAL PRESSURE (PSF) P yD = AT REST HYDROSTATIC UNIT WEIGHT (PCF) BELOW GRADE WALL (At—Rest Condition) = ryA (1ha) ha pt = 'YA • (h+thha) h = HEIGHT OF WALL (Fr) ha= HEIGHT OF SLOPE (FT) h P� = LATERAL PRESSURE, TOP OF WALL (PSF) P2 = LATERAL PRESSURE, BOTTOM OF WALL (PSF) ryA = ACTIVE HYDROSTATIC UNIT WEIGHT (PCF) CANTILEVER WALL-SLOPING BACKFILL (Active with Surcharge) Example Lateral • Earth Pressure Distributions COLORADO GROUNDWATER RESOURCE SERVICES,INC. FIGURE 2 CONQUEST OIL FACILITY AT 81619 WCR 77 CTL I T PROJECT NO.FC03805.025-125 • APPENDIX A FIELD BOREHOLE LOGS • • CGRS FIELD BOREHOLE LOG BOREHOLE NUMBER ii SB-1 PROJECT NUMBER : 1-8019-12667a2 TOTAL DEPTH :40' PROJECT NAME: Conquest Oil C8 TOP OF RISER : 100.00 LOCATION : Grover, CO Drilling Engineers STATIC WATER LEVELS(BGS) DRILLING CO : - --- + DRILLING METHOD : 8.25" HSA Time 845 DRILLER: Date 9/30/2010 LOGGED BY:Craig Mulica Water Level Dry START: 9/29/2010 COMPLETED : 9/29/2010 Casing Depth— 43.10 c } ai 2 'g NOTES O WELL WELL i--o. Z co c ace DESCRIPTION (ppm) p CONSTRUCTION DESIGN I v m O a, m =_o E E E E °' J u) in m to g O i - Stick Up SILTY_SAND: Light brown, 'r T rT T= :.' AT- r.T-" „• Bentonite A 1 NA 60 60 - subrounded,very fine grained, -• T T T T= •;s;• F medium dense,moist,slight gravel 'T T r i -t_5 (SM-GM) Y SCH.40 PVC Riser SB 2 20 12 10 i0.0@5'bgs ••...x. WELL GRADED SAND:Tan, ••-•, • • subanguiar,fine to coarse-grained, - 1 dense,moist,slight gravel(SW) I ;• :�•• > _ SB 3 26 12 12 0.0 @ 10'bgs - CLAY:Gray with rust brown, _'u• medium plastic to plastic,stiff to - very stiff @ 25'bgs. moist,iron = : oxidation color from 9'to 25'bgs; 0.2 15'bgs Y'` SB 4 18 12 12 1 increased silt content from 25'to @ = - 30'bgs,blocky from 30'to 40'bgs `i• - (CL) .;$-':' A: 2 .,<'•_..:.: 10/20 Silica Sand SB 5 25 12 8 _ 0.6 @ 20'bgs; _s>; _ Sample := :1.• Retained for .��:,,�; . - Analysis • '='. �• SB 6 39 12 8 2 0.5@25'bgs '`I�' " SB 7 50 12 3 0.4 re 30'bgs i = 3 0.5@35'bgs "" SB 8 39 8 x'Sch40PVC B 9 49 9 _ 0.4 @ 40'bgs \ ` `''`'. Screen End of Boring @ 40'bgs / CGRS FIELD BOREHOLE LOG BOREHOLE NUMBER 01 SB-2 PROJECT NUMBER : 1-8019-12667aa TOTAL DEPTH : 30' PROJECT NAME: Conquest Oil C8 TOP OF RISER :96.29 LOCATION : Grover,CO DRILLING CO: Drilling Engineers STATIC WATER LEVELS (BGS) DRILLING METHOD : 8.25" HSA Time 850 DRILLER: Date 9/30/2010 LOGGED BY:Craig Mulica Water Level Dry START: 9/29/2010 COMPLETED : 9/29/2010 Casing Depth 33.30 C C v NOTES WELL WELL 1- i c cc DESCRIPTION (ppm) p CONSTRUCTION DESIGN m i d a, F i E E o EE d w w c2 miiicn i --- Stick Up •HA 1 NA 24 24 '0 SILTY SAND:Medium brown, :r T.T, subround,very fine-grained,dense 7 T Y.r. " Bentonite SB 2 20 12 12 ` • (SM) 0.1 �2'bgs YTT _-_5 CLAY:Gray with rust brown,stiff 2"SCH.40 PVC Riser SB 3 24 12 12 _ to very stiff,medium plastic to 0.0 @ 5'bgs plastic,moist,iron oxide coloring _ from 5'10 30'bgs,blocky from 15' r to 30'bgs(CL) SB 4 23 12 12 T-1 0.102410'bgs • _1 5 @ bgs; 10/20 Silica Sand SB 5 31 12 12 0. 15 b Sample Retained for :t' - Analysis a SB 6 28 12 12 T_2 0.2 @ 20'bgs '`- _ ;A} SB 7 32 12 12 + -25 0.6@25'bgs _ = 2"Sch 40 PVC Screen •B 8 31 12 12 0.5@30'bgs End of Boring @ 30'bgs / 01 CGRS FIELD BOREHOLE LOG BOREHOLE NUMBER SB-3 PROJECT NUMBER: 1-80 1 9-1 2667aa TOTAL DEPTH: 25' PROJECT NAME: Conquest C8 TOP OF RISER:- (with cap removed, LOCATION: Grover, CO -' STATIC WATER LEVELS(BGS) DRILLING CO: Drilling Engineers DRILLING METHOD: 8.25"HSA Time DRILLER: Date LOGGED BY: Craig MUliCa Water Level START: 9/29/2010 COMPLETED: 9/29/2010 Casing Depth r c Notes UTHOLOGY 2 c DEPTH DESCRIPTION (ppm) v a) a) m E ci _ a a o E E CO —0 --- -, . , . / SILTY SAND WITH GRAVEL: isii>• i i • _ Medium brown, subround, very / i." i. fine-grained, loose, moist(SM- ®/ / ® e / / / - \GM) WELL GRADED SAND: SB 1 7 12 12 -5 Medium brown, subangular, 0.4 @ 5' ` fine to coarse-grained, medium bgs;Sample : - dense, moist(SVV) Retained for L Analysis SILTY SAND: Light brown, r.TT 1- 7-.•r.T.• - fine-grained, h-T T TT T T T, subround, very I Inp�rained, T'T.T T.T T.'T T" `.1 T.• T' T'r. T 1 SB 2 19 12 12 -10 dense, moist(SM) 0.1 @ 10'bgs TT.:TT..T.'.TT TT.T. 'T.'T:.T.'.TT.T.•T'.T.•7. •TT TT.TT-rTZ CLAY: Gray with rust brown, stiff to very stiff, medium plastic to plastic, moist, iron oxide SB 3 19 12 12 '-15 coloring from 12'to 25' bgs 0.7 @ 15'bgs SB 4 25 12 12 -20 0.2 @ 20'bgs SB 5 27 12 12 0-3 @ 25' bgs • — 25 \EndofBonng25 bgs ./ CGRS HELD BOREHOLE LOG BOREHOLE NUMBER • SB-4 PROJECT NUMBER : 1-8019-12667ae TOTAL DEPTH : 40' PROJECT NAME : Conquest Oil C8 TOP OF RISER :99.46 LOCATION : Grover, CO DRIWNG CO: Drilling Engineers STATIC WATER LEVELS(BGS) DRILLING METHOD : 8.25" HSA Time 900 DRILLER : Date 9/30/2010 -r-- - LOGGED BY:Craig Mulica Water Level 33.31 START: 9/29/2010 COMPLETED : 9/29/2010 Casing Depth 43.10 _ C ee .- m t- q NOTES 0 WELL WELL z m C DESCRIPTION cc (PPM) p CONSTRUCTION DESIGN 0 . 0 m m I I rn aE E III- J -ii - Stick Up -0 WELL GRADED SAND: Medium ! i brown,subangular,fine to coarse- : -- Bentonite grained, medium dense,moist (SW) 2"SCH.40 PVC Riser SB 1 10 12 6 _ 5 0.2@5'bgs CLAY:Gray with rust brown,stiff SB 2 19 12 12 _ -1 to very stiff,medium plastic to 0.7 @ 10' "` plastic.iron oxide coloring from 8' bgs;Sample i to 40'bgs,increased silt content Retained for =:: a 20'bgs(CL) Analysis SB 3 22 12 12 ... SB 4 29 12 12 _-2 0.1 @ 20'bgs -`-~'" — 't�2o Silica sand -- -2 — SB 5 30 12 12 , 0.3 @ 30'bgs : .: ,.; ~ -3 s:` B 6 47 12 12 0.2 @ 40'bgs ` '` r scn 4o PVC \\ — screen End of Boring @ 40'bgs • APPENDIX B RESULTS OF LABORATORY TESTING • • • _ 3 EXPANSION UNDER CONSTANT 2 ._ _.. - - .. .. .. -__ _ PRESSURE DUE TO WETTING _ O N a -+ X O fq to W a 2 O U 0.1 1.0 10 100 • APPLIED PRESSURE-KSF Sample of CLAY,SANDY(CL) DRY UNIT WEIGHT= 113 PCF From SB-1 AT 10 FEET MOISTURE CONTENT= 15.6 i= 3 EXPANSION UNDER CONSTANT 2 _ PRESSURE DUE TO WETTING z O o z a ' O• -2 - 471 CC O p.1 1.0 10 100 • APPLIED PRESSURE-KSF Sample of CLAY,SANDY(CL) DRY UNIT WEIGHT= 106 PCF From SB-1 AT 15 FEET MOISTURE CONTENT= 20.8 COLORADO GROUNDWATER RESOURCE SERVICES.INC. Swell Consolidation CONQUEST OIL FACILITY AT 61619 WCR 77 CTL I T PROJECT NO.FC03645.025-125 Test Results r,nnnr o 4 • • 8 -. EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 4 - 9 0 O .. . . 0 Cr) Q a x W 2 Co rn W 0. 0 U a 0.1 1.0 10 100 APPLIED PRESSURE-KSF • Sample of CLAY,SANDY(CL) DRY UNIT WEIGHT= 93 PCF From SB-2 AT 2 FEET MOISTURE CONTENT= 11.6 % Swell Consolidation COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACIUTY AT 81819 WCR 77 Test Results. CTL I T PROJECT NO.FC03845.025-125 FIGIIRF R-9 • 8 7 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 0 1 • .1 • a O ▪ -4 w z yO 5 - Ui W Q a $ 0 U -7 0.1 1.0 10 100 APPLIED PRESSURE-KSF • Sample of CLAY,SANDY(CL) DRY UNIT WEIGHT= 117 PCF From SB-2 AT 5 FEET MOISTURE CONTENT= 12.6 % COLORADO GROUNDWATER RESOURCE SERVICES,INC. Swell Consolidation CONQUEST OIL FACILITY AT 81818 WCR n Test Results CTL I T PROJECT NO.FC03845.025-125 riot IL7F [3_9 7 8 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 5 . 4 . Q .__ O d U) - Z Q O.K 5 _ W Z O $ - N W CC -7 - _ O C) -8 0.1 1.0 10 100 APPLIED PRESSURE- KSF • Sample of CLAY,SANDY(CL) DRY UNIT WEIGHT= 106 PCF From SB-2 AT 10 FEET MOISTURE CONTENT 21.0 q Swell Consolidation COLORADO GROUNDWATER RESOURCE SERVICES,INC, CONQUEST OIL FACILITY AT 81619 WCR 77 Test Results CTL I T PROJECT NO.FC03645.025-125 FIGI IRF R-4 • T HYDROMETER ANALYSIS SIEVE ANALYSIS 25 HR 7 HR TIME READINGS U.S.STANDARD SERIES CLEAR SQUARE OPENINGS 45 MIN. 15 MIN 60 IAN 19 MIN. 4 MIN. 1 MIN. •200 '100 '50 '40 '30 '18 '10'8 '4 3/8' 3N' 1W 3' 5'6' 8' 100 _.0 90 t` 10 010 dl 35 60 6 w C .. A'. 10 .:`" 90 001 0.002 .005 .009 .019 937 .W4 .149 .297 0.42590 1.19 2.0 2.38 4.78 952 191 36.1 762 127152 200 DIAMETER OF PARTICLE IN MILLIMETERS SANDS GRAVEL CLAY(PLASTIC)TO SILT(NON-PLASTIC) FINE I MEDIUM I COARSE FINE I COARSE )COBBLES Sample of SAND(SP) GRAVEL 26 % SAND 71 % LL From SB• 1 AT 5 FEET _. SILT&CLAY 3 %• LIQUID LIMIT PLASTICITY INDEX % HYDROMETER ANALYSIS ) SIEVE ANALYSIS • 25 HR. 7 HR. TIME READ84GS U.S.STANDARD SERIES CLEAR SQUARE OPENINGS 45 MIN. 15 MIN. 60 MIN. 19 MIN. 4 MIN. 1 MIN. '200 '100 '50 '40 '30 '16 10 '8 '4 3/8' 3/4' 115' 3' 5'6' 8'0 10 .. _. - 20 Z]0 30 W Z 50 50 w u a a 0. i 40 _. - ---80 a 30 -_ - -. 80 _. _:90 _- -. -::100 001 0002 005 .009 019 037 074 149 297 0.4i590 1.19 2.0 238 4.78 9.52 191 36.1 762 12,X200 1DIAMETER OF PARTICLE IN MILLIMETERS SANDS GRAVEL CLAY(PLASTIC)TO SILT(NON-PLASTIC) FINE ) MEDIUM )COARSE FINE ) COARSE I COBBLES Sample of CLAY,SANDY(CL) GRAVEL 0 % SAND 20 % • From SB-2 AT 2 FEET SILT&CLAY 80 % LIQUID LIMIT 44 PLASTICITY INDEX 26 To Gradation COLORADO GROUNDWATER RESOURCE SERVICES,INC. Test Results CONQUEST OIL FACILITY AT 61619 WCR 77 CTL I T PROJECT NO.FC03645.025-125 ain't IDC 0 C • 1 HYDROMETER ANALYSIS SIEVE ANALYSIS 25 HR. 7 HR. TIME READINGS U.S.STANDARD SERIES CLEAR SQUARE OPENINGS 45 MIN. 15 MIN. 60 MIN. 19 MIN. 4 MIN. 1 MIN. '200 '100 '50 '40 '30 '18 '10 '8 '4 3/8' 3/4' 1N 3' 5'8' W 100 0 90 .._:-:..._. 10 80 .. . . 20 C7 70 t .. . .—.. 30 o 2 1 60 . .. a .__. _ .. 40 w cr F U 50 50 w w (.1 0. 40 .. a BO 30 70 . ......... 20 80 10 __._. .-�.__ 90 ...=:. _.0 100 .001 0.002 .005 .009 .019 .037 .074 .149 .297 590 1.19 2.0 2.38 4.78 9.52 19.1 38.1 78.2 127 200 0.42 152 DIAMETER OF PARTICLE IN MILLIMETERS CLAY(PLASTIC)TO SILT(NON-PLASTIC) SANDS GRAVEL FINE I MEDIUM I COARSE FINE 1 COARSE ! COBBLES Sample of SAND, SLIGHTLY S_SILTY(SP-SM) GRAVEL 20 % SAND 74 Ill From SB-3 AT 5 FEET SILT&CLAY 6 % L1QUID LIMIT % PLASTICITY INDEX S Gradation COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 Test Results CTL I T PROJECT NO.FC03645.025-I25 Gic i IC1G R_R • ; ( } to § cn § / // ` klkkkk7 k \\\\/k $�®( \ 9n Oh a # Wkly © al to 7#a w N ■ in w r(\( §§ el B CC C § .o!= o �)§w /S /§ | w o- Bk fz = 0142 ; r§tn b 7§2 cc VI- cc §\ ■ > _ on 2 § @2 ! 8 Li g. k�z; @q / ) 2= / /( . e = , toe. )\> (/\ • 2 : : : | 222 0§/ § , � � m � „ )§! g is • In APPENDIX C SAMPLE SITE GRADING SPECIFICATIONS • • • SAMPLE SITE GRADING SPECIFICATIONS 1. DESCRIPTION This item shall consist of the excavation, transportation, placement and compaction of materials from locations indicated on the plans, or staked by the Engineer, as necessary to achieve building site elevations. 2. GENERAL The Soils Engineer shall be the Owner's representative. The Soils Engineer shall approve fill materials, method of placement, moisture contents and percent compaction, and shall give written approval of the completed fill. 3. CLEARING JOB SITE The Contractor shall remove all trees, brush and rubbish before excavation or fill placement is begun. The Contractor shall dispose of the cleared material to provide the Owner with a clean, neat appearing job site. Cleared material shall not be placed in areas to receive fill or where the material will support structures of any kind. 4. SCARIFYING AREA TO BE FILLED All topsoil and vegetable matter shall be removed from the ground surface upon which fill is to be placed. The surface shall then be plowed orscarified to a depth of 8 inches until the surface is free from ruts, hummocks or other uneven features, which would prevent uniform compaction by the equipment to be used. 5. COMPACTING AREA TO BE FILLED After the foundation for the fill has been cleared and scarified, it shall be disked or bladed until it is free from large clods, brought to the proper moisture content and compacted to not less than 95 percent of maximum dry density as determined in accordance with ASTM D 698 or AASHTO T 99. 6. FILL MATERIALS On-site materials classifying as CL, SC, SM, SW, SP, GP, GC, and GM are acceptable. Fill soils shall be free from organic matter, debris, or other deleterious substances, and shall not contain rocks or lumps having a diameter greater than three (3) inches. Fill materials shall be obtained from the existing fill and other approved sources. 7. MOISTURE CONTENT Fill materials shall be moisture treated. Sand soils can be moistened to within 2 percent of optimum moisture content. Sufficient laboratory compaction tests shall be performed • to determine the optimum moisture content for the various soils encountered in borrow areas. COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 C-1 CTL T PROJECT NO.FC03845.025-1 25 S The Contractor may be required to add moisture to the excavation materials in the borrow area if, in the opinion of the Soils Engineer, it is not possible to obtain uniform moisture content by adding water on the fill surface. The Contractor may be required to rake or disk the fill soils to provide uniform moisture content through the soils. The application of water to embankment materials shall be made with any type of watering equipment approved by the Soils Engineer, which will give the desired results. Water jets from the spreader shall not be directed at the embankment with such force that fill materials are washed out. Should too much water be added to any part of the fill, such that the material is too wet to permit the desired compaction from being obtained, rolling and all work on that section of the fill shall be delayed until the material has been allowed to dry to the required moisture content. The Contractor will be permitted to rework wet material in an approved manner to hasten its drying. 8. COMPACTION OF FILL AREAS Selected fill material shall be placed and mixed in evenly spread layers. After each fill layer has been placed, it shall be uniformly compacted to not less than the specified percentage of maximum dry density. Fill materials shall be placed such that the thickness of loose material does not exceed 8 inches and the compacted lift thickness • does not exceed 6 inches. Compaction, as specified above, shall be obtained by the use of sheepsfoot rollers, multiple-wheel pneumatic-tired rollers, or other equipment approved by the Engineer. Compaction shall be accomplished while the fill material is at the specified moisture content. Compaction of each layer shall be continuous over the entire area. Compaction equipment shall make sufficient trips to insure that the required dry density is obtained. 9. COMPACTION OF SLOPES Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction operations shall be continued until slopes are stable, but not too dense for planting, and there is no appreciable amount of loose soil on the slopes. Compaction of slopes may be done progressively in increments of three to five feet(3'to 5') in height or after the fill is brought to its total height. Permanent fill slopes shall not exceed 3:1 (horizontal to vertical). 10. DENSITY TESTS Field density tests shall be made by the Soils Engineer at locations and depths of his choosing. Where sheepsfoot rollers are used, the soil may be disturbed to a depth of several inches. Density tests shall be taken in compacted material below the disturbed surface. When density tests indicate that the dry density or moisture content of any layer of fill or portion thereof is below that required, the particular layer or portion shall be • reworked until the required dry density or moisture content has been achieved. COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 C-2 CTL T PROJECT NO.FC03645.025-125 11. COMPLETED PRELIMINARY GRADES All areas, both cut and fill, shall be finished to a level surface and shall meet the following limits of construction: A. Overlot cut or fill areas shall be within plus or minus 2/10 of one foot. B. Street grading shall be within plus or minus 1/10 of one foot. The civil engineer, or duly authorized representative, shall check all cut and fill areas to observe that the work is in accordance with the above limits. 12. SUPERVISION AND CONSTRUCTION STAKING Observation by the Soils Engineer shall be continuous during the placement of fill and compaction operations so that he can declare that the fill was placed in general conformance with specifications. All site visits necessary to test the placement of fill and observe compaction operations will be at the expense of the Owner. All construction staking will be provided by the Civil Engineer or his duly authorized representative. Initial and final grading staking shall be at the expense of the owner. The replacement of grade stakes through construction shall be at the expense of the contractor. • 13. SEASONAL LIMITS No fill material shall be placed, spread or rolled while it is frozen, thawing, or during • unfavorable weather conditions. When work is interrupted by heavy precipitation, fill operations shall not be resumed until the Soils Engineer indicates that the moisture content and dry density of previously placed materials are as specified. 14. NOTICE REGARDING START OF GRADING The contractor shall submit notification to the Soils Engineer and Owner advising them of the start of grading operations at least three (3) days in advance of the starting date. Notification shall also be submitted at least 3 days in advance of any resumption dates when grading operations have been stopped for any reason other than adverse weather conditions. 15. REPORTING OF FIELD DENSITY TESTS Density tests made by the Soils Engineer, as specified under "Density Tests" above, shall be submitted progressively to the Owner. Dry density, moisture content and percent compaction shall be reported for each test taken. 16. DECLARATION REGARDING COMPLETED FILL The Soils Engineer shall provide a written declaration stating that the site was filled with acceptable materials, or was placed in general accordance with the specifications. • COLORADO GROUNDWATER RESOURCE SERVICES,INC. CONQUEST OIL FACILITY AT 61619 WCR 77 C-3 CTL IT PROJECT NO.FC03645.025-125 • APPENDIX D PAVEMENT CONSTRUCTION RECOMMENDATIONS • • SUBGRADE PREPARATION Moisture Treated Subarade (MTSI 1. The subgrade should be stripped of organic matter, scarified, moisture treated and compacted to the specifications stated below in Item 2. The compacted subgrade should extend at least 3 feet beyond the edge of the pavement where no edge support, such as curb and gutter, are to be constructed. 2. Sandy and gravelly soils (A-1-a, A-1-b, A-3, A-2-4, A-2-5, A-2-6, A-2-7) should be moisture conditioned near optimum moisture content and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). Clayey soils (A-6, A-7-5, A-7-6) should be moisture conditioned between optimum and 3 percent above optimum moisture content and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). 3. Utility trenches and all subsequently placed fill should be properly compacted and tested prior to paving. As a minimum, fill should be compacted to 95 percent of standard Proctor maximum dry density. • 4. Final grading of the subgrade should be carefully controlled so the design cross-slope is maintained and low spots in the subgrade that could trap water are eliminated. 5. Once final subgrade elevation has been compacted and tested to compliance and shaped to the required cross-section, the area should be proof-rolled using a minimum axle load of 18 kips per axle. The proof-roll should be performed while moisture contents of the subgrade are still within the recommended limits. Drying of the subgrade prior to proof-roll or paving should be avoided. 6. Areas that are observed by the Engineer that have soft spots in the subgrade, or where deflection is not uniform of soft or wet subgrade shall be ripped, scarified, dried or wetted as necessary and recompacted to the requirements for the density and moisture. As an alternative, those areas may be sub-excavated and replaced with properly compacted structural backfill. Where extensively soft, yielding subgrade is encountered; we recommend a representative of our office observe the excavation. • COLORADO GROUNDWATER RESOURCE SERVICES,INC. D-1 CONQUEST OIL FACILITY AT 61619 WCR 77 CTL T PROJECT NO.FC03645.025-125 • PAVEMENT MATERIALS AND CONSTRUCTION Portland Cement Concrete (PCC) 1. Portland cement concrete should consist of Class P of the 2005 CDOT- Standard Specifications for Road and Bridge Construction specifications for normal placement or Class E for fast-track projects. PCC should have a minimum compressive strength of 4,200 psi at 28 days and a minimum modulus of rupture (flexural strength) of 600 psi. Job mix designs are recommended and periodic checks on the iob site should be made to verify compliance with specifications. 2. Portland cement should be Type II "low alkali" and should conform to ASTM C 150. 3. Portland cement concrete should not be placed when the subgrade or air temperature is below 40°F. 4. Concrete should not be placed during warm weather if the mixed concrete has a temperature of 90°F, or higher. 5. Mixed concrete temperature placed during cold weather should have a • temperature between 50°F and 90°F. 6. Free water should not be finished into the concrete surface. Atomizing nozzle pressure sprayers for applying finishing compounds are recommended whenever the concrete surface becomes difficult to finish. 7. Curing of the portland cement concrete should be accomplished by the use of a curing compound. The curing compound should be applied in accordance with manufacturer recommendations. 8. Curing procedures should be implemented, as necessary, to protect the pavement against moisture loss, rapid temperature change, freezing, and mechanical injury. 9. Construction joints, including longitudinal joints and transverse joints, should be formed during construction or sawed after the concrete has begun to set, but prior to uncontrolled cracking. 10. All joints should be properly sealed using a rod back-up and approved epoxy sealant. 11. Traffic should not be allowed on the pavement until it has properly cured and achieved at least 80 percent of the design strength, with saw joints already cut. • COLORADO GROUNDWATER RESOURCE SERVICES,INC. D-2 CONQUEST OIL FACILITY AT 61619 WCR 77 CTL I T PROJECT NO.FC03645.025-125 • 12. Placement of portland cement concrete should be observed and tested by a representative of our firm. Placement should not commence until the subgrade is properly prepared and tested. • • COLORADO GROUNDWATER RESOURCE SERVICES,INC. D-3 CONQUEST OIL FACILITY AT 61619 WCR 77 CTL IT PROJECT NO.FC03645.025-125 • APPENDIX E PAVEMENT MAINTENANCE PROGRAM • • Jr! MAINTENANCE RECOMMENDATIONS FOR RIGID PAVEMENTS High traffic volumes create pavement rutting and smooth polished surfaces. Preventive maintenance treatments will typically preserve the original or existing pavement by providing a protective seal and improving skid resistance through a new wearing course. 1. Annual Preventive Maintenance a. Visual pavement evaluations should be performed each spring or fall. b. Reports documenting the progress of distress should be kept current to provide information of effective times to apply preventive maintenance. c. Crack sealing should be performed annually as new cracks appear. 2. 4 to 8 Year Preventive Maintenance a. The owner should budget for a preventive treatment at approximate intervals of 4 to 8 years to reduce joint deterioration. b. Typical preventive maintenance for rigid pavements includes patching, crack sealing and joint cleaning and sealing. c. Where joint sealants are missing or distressed, resealing is • mandatory. 3. 15 to 20 Year Corrective Maintenance a. Corrective maintenance for rigid pavements includes patching and slab replacement to correct subgrade failures, edge damage, and material failure. b. Asphalt concrete overlays may be required at 15 to 20 year intervals to improve the structural capacity of the pavement. • COLORADO GROUNDWATER RESOURCE SERVICES,INC. E_1 CONQUEST OIL FACILITY AT 81619 WCR 77 CTL(T PROJECT NO.FC03645.025-125 Hello