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HomeMy WebLinkAboutKUM & GO #0951 - FDP230009 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT REPORT OF GEOTECHNICAL EXPLORATION KUM & GO STORE #0951 ___________________________ EAST PROSPECT ROAD AND SOUTH LEMAY AVE FORT COLLINS, CO PREPARED FOR KUM & GO, L.C. June 24, 2021 Olsson Project No. 020-28830 Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 TABLE OF CONTENTS Project Understanding ......................................................................................................................... 1 1.1. Geotechnical Scope ................................................................................................................. 1 1.2. Site Location and Description .................................................................................................. 1 1.3. Project Information ................................................................................................................... 2 Exploratory and Test Procedures ....................................................................................................... 3 2.1. Field Exploration ....................................................................................................................... 3 2.2. Laboratory Testing .................................................................................................................... 3 Subsurface Conditions......................................................................................................................... 4 3.1. Area Geology ............................................................................................................................ 4 3.2. Test Borings and Laboratory Summary .................................................................................. 4 3.3. Soil Properties ........................................................................................................................... 4 3.4. Groundwater Summary ............................................................................................................ 5 3.5. Corrosivity of Soils .................................................................................................................... 6 3.6. Evaluation of On-Site Soils ...................................................................................................... 6 Site Preparation.................................................................................................................................... 8 4.1. General Site Preparation .......................................................................................................... 8 4.2. Structural Fill ............................................................................................................................. 9 4.3. Utilities ..................................................................................................................................... 11 4.4. Drainage and Groundwater Considerations ......................................................................... 12 4.5. Construction Equipment Mobility ........................................................................................... 13 4.6. Temporary Slopes and Excavations ..................................................................................... 13 Buildings and Structures .................................................................................................................... 15 5.1. Shallow Foundation Design ................................................................................................... 15 5.2. Monument Sign/Deep Foundation Design ............................................................................ 16 5.3. Seismic Classification ............................................................................................................. 18 5.4. Floor Slab Design ................................................................................................................... 19 5.5. Exterior Slabs and Sidewalks ................................................................................................ 20 5.6. Lateral Earth Pressures ......................................................................................................... 20 5.7. UST Excavation Areas – Existing .......................................................................................... 22 5.8. Underground Fuel Tanks - New ............................................................................................ 24 Pavements ......................................................................................................................................... 25 6.1. Pavement Subgrade Preparation .......................................................................................... 25 6.2. Pavement Design – Site Parking and Drive Areas ............................................................... 26 Limitations .......................................................................................................................................... 28 APPENDICES Appendix A: Site Location Plan, Boring Location Map Appendix B: Symbols and Nomenclature, Boring Logs Appendix C: Summary of Laboratory Test Results Appendix D: Geologic Profile, Cross Section Map Appendix E: Potential Swelling Soil Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 Kum & Go Fact Sheet Store # 0951 Project address: S Lemay Ave & E Prospect Rd Fort Collins, CO Date: 6/24/2021 Engineer: Ed Schnackenberg, PE Phone #: 402-827-7220 SITE PREPARATION Is building demolition necessary (Y/N): Convenience store, homes, and outbuildings Yes See Report Are below grade structures known to exist (basements, crawlspaces, UST's) (Y/N/U): Yes Existing UST’s Above or below ground utility demolition/relocation (Y/N/U): Yes See Report Is shoring anticipated during construction (Y/N): Yes See Report Old fill encountered that will require rework (Y/N): Yes See Report Estimated topsoil stripping depth (in): 6 Scarification thickness (in): 12 Proofrolling (Y/N): Where feasible. Not recommended in areas of fuel lines or UST installation Yes See Report Highest recorded groundwater depth from existing grade (ft): 7.1 Lowest recorded groundwater depth from existing grade (ft): 14.0 Unsuitable or unstable soil identified during exploration (Y/N): No See Report Exterior pavement subgrade preparation thickness (in): 12 See Report Pavement underslab drainage system recommended (Y/N): No Additional pavement subgrade recommendations necessary (Y/N): Yes See Report Do available reports indicate the site was utilized by others prior to Kum & Go (Y/N): Yes See Report Additional Comments: Aggregate base underlying pavements required to provide capillary break from clay subgrade STRUCTURAL FILL On site soils suitable for reuse? (Y/N): Yes See Report Import Fill Soils Maximum Liquid Limit (%): 45 Import Fill Soils Maximum Plastic Limit (%): 25 Maximum Swell Potential (%): 1% Maximum Particle Size (in): 3 Recommended lift thickness (in): 4 to 8 Additional Comments: The building footprint and 10’ around the building should be overexcavated to a depth of 24” below grade. FOUNDATION DESIGN/FLOOR SLAB Recommended Building Foundation Type: Shallow Spread (or Trench Type) Foundations Finish Floor Elevation (ft): 4951.0 Recommended Frost Depth (in) 42 Are overexcavation and structural fill recommended below shallow foundations? (Y/N): Yes/No See Report Is surcharge or preload necessary to prepare the building pad (Y/N): No Net allowable soil bearing pressure (psf): 2,500 Minimum column footing width dimensions (in): 24 Minimum continuous footing width dimensions (in): 18 Are perimeter foundation drains recommended for the building (Y/N) No Floor slab subgrade preparation thickness (in): 12 See Report **This Fact Sheet only provides a limited overview of the report and is subject to any and all clarifications, conditions, contingencies, limitations and/or qualifications that may exist in the body of the report. The information contained in this Fact Sheet is provided pursuant to Client’s request and is provided solely for the convenience of Client and neither Client nor any other party can rely solely on this Fact Sheet. Client and any other party using this report must review the entire report and interpret the information contained in this Fact Sheet in conjunction with the remainder of the report. Created by: Ed Schnackenberg, PE Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 1 PROJECT UNDERSTANDING 1.1. GEOTECHNICAL SCOPE This Report of Geotechnical Exploration was requested and authorized by Mr. Ryan Halder of Kum & Go, L.C. (Kum & Go) for the purpose of evaluating existing subsurface conditions and providing geotechnical design recommendations for the new Kum & Go #00951 building, signs, and pavements. The scope of this geotechnical exploration included: · Site reconnaissance and review of soil and geologic subsurface information from USDA Natural Resource Conservation Services (NRCS). · Review of the project site concept plan entitled “Concept Plan” dated 05/28/2021. · Review of the ALTA Survey completed by Lat40 titled “ALTA/NSPS Land Title Survey, Kum & Go #951, Lot 5, East Acres, Being a Portion of the Northeast Quarter of Section 24, Township 7 North, Range 69 West of the 6th P.M., City of Fort Collins, County of Larimer, State of Colorado. · Drilling and sampling of six (6) soil test borings extending to depths of approximately 10.0 to 25.5 feet below existing grades. · Laboratory testing (as noted in the appendices) of soil samples obtained during the field operations. · Completion of a geotechnical engineering evaluation using information obtained from our field observations, soil test borings, and laboratory testing program. · Preparation of this Report of Geotechnical Exploration presenting the soil test borings, laboratory test results, and a summary of our engineering evaluations and recommendations. The scope of this geotechnical exploration did not include an environmental assessment for determining the presence of wetlands and/or hazardous or toxic materials in the soil or groundwater on or near this site. Statements in this report regarding odors, discoloration, or suspicious conditions are strictly for the information of our client. 1.2. SITE LOCATION AND DESCRIPTION The 0.921-acre Kum & Go project site is situated in the southwest quadrant of the intersection of S Lemay Avene and E Prospect Road in Fort Collins, Colorado. The preliminary ALTA survey completed by Lat40 indicates the site has about 2 feet of total grade change sloping from about 4,948 feet on the south side to 4,950 feet on the north side. The site is currently occupied by a Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 2 convenience store/gas station in the northeast corner and single-story homes and outbuildings around the remainder of the property. From our review of readily available aerial images obtained from Google Earth, the site has remained relatively unchanged dating back to as early as 1985. A Site Location Plan and Boring Location Map are presented in Appendix A. A preliminary finished floor elevation (FFE) of 4951.0 feet for the new Kum & Go building was provided on the current Rec Site Plan (Dated 06/16/2021). Based on the existing topography and the proposed FFE, we anticipate new cut and fill depths on the order of 2 feet or less may be required to achieve final design grades. If the final FFE changes from the estimate provided, Olsson geotechnical engineers should be contacted to determine if the recommendations of this report remain valid. 1.3. PROJECT INFORMATION We understand the new Kum & Go facility will include an approximately 3,946-square foot, single- story, building utilizing light gauge steel framework and cast stone veneer to be located on the north side of the project site, facing south, with the trash enclousre located along the western perimeter of the site. New automobile fuel pump islands with an overhead canopy (24’ x 108’) will be positioned south of the new building. The underground storage tanks (UST) will be positioned along the south property line, just south of the pump islands. Parking areas will be constructed just south of the building. Access to the facility will be provided by an entrance from S Lemay Avenue at the southeast corner of the property. Based on our experience with the Kum & Go building design, Olsson understands maximum live and dead loads for the new building will be on the order of 41 kips each for isolated columns, 1.5 klf for continuous walls, and 125 psf for floor slabs. Olsson understands that the type and design of canopy support foundations will be determined by the Canopy Manufacturer/Installer based on their review of the contents of this geotechnical report and the soil conditions encountered at the time of foundation installation. Olsson will provide recommendations for canopy foundation design, subgrade improvements, or stabilization of canopy foundation subgrades if requested by Kum & Go. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 3 EXPLORATORY AND TEST PROCEDURES 2.1. FIELD EXPLORATION For this project, a truck-mounted CME 55 drill rig utilizing solid-stem continuous flight augers was used to complete six (6) soil test borings extending to depths of 10.5 to 24.3 feet below existing grades. Preliminary soil boring depths and locations were selected by Olsson and reviewed during the proposal phase of this project. The soil boring locations and depths were modified or shifted in the field only if necessary to avoid known underground or overhead utilities, existing structures, site features, public right-of-way, or areas of limited access. Refer to the Boring Location Map in Appendix A and the Boring Logs in Appendix B for the final locations and depths of each boring. Relatively undisturbed and split-barrel soil samples were obtained at staggered intervals during the drilling process. Soil samples designated as "U" samples on the boring logs were obtained in general accordance with ASTM D-1587 (Thin-Walled Tube Sampling of Soils). Soil samples designated as “SS” were obtained in general accordance with ASTM D-1586 (Penetration Test and Split-Barrel Sampling of Soils). Soil samples designated as "MC" on the boring logs were obtained in general accordance with ASTM D-3550 (Thick Wall, Ring-Lined, Split-Barrel, Drive Sampling of Soils) with a Modified California Barrel Sampler. The “MC” sampler was driven to a 12-inch depth, as it can only sample a maximum 16-inches of soil. Recovered samples were sealed in plastic containers or sampling tubes, labeled, and protected for transportation to the laboratory for testing. 2.2. LABORATORY TESTING Per the laboratory scope and sample conditions, tests were completed to evaluate the engineering properties of recovered soil samples. Moisture content and density tests were completed to determine the existing moisture state and unit weight of subsurface soils. Unconfined compression tests were completed to determine the shear strengths of undisturbed cohesive soils. Sieve analysis and P-200 (Percent Passing a #200 Sieve) tests were completed to determine the particle size distribution of on-site soils. One-dimensional swell and consolidation testing on select samples to evaluate the swelling and/or collapse potential of on-site soils. Atterberg limits tests were completed to help classify cohesive samples and determine the soil plasticity. A corrosion series was performed on a bulk soil sample. Laboratory tests were conducted in general accordance with current ASTM test procedures. A summary of the laboratory test results is presented in Appendix C. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 4 SUBSURFACE CONDITIONS 3.1. AREA GEOLOGY Based on the U.S. Department of Agriculture’s (USDA) Natural Resources Conservation Service (NRCS) soil survey data (https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx), the project site appears to consist primarily of Nunn clay loam (1 to 3 percent slopes), which is comprised of clay loam, clay, loam, and gravelly sandy loam. The composition of the unit is 90- percent Nunn and similar soils and 10 percent minor components. The soil unit reports bedrock deeper than 80 inches and is categorized into hydrologic group C with an estimated depth to the water table of 24 to 36 inches. Review of Potentially Swelling Soil and Rock in the Front Range Urban Corridor mapping by Hart (1974), the project site is situated in an area with low to moderate swell potential which Hart notes includes variable thicknesses of surficial deposits and may have higher swell potential in underlying bedrock units. Based on our experience in the immediate area, shallow soils and bedrock predominantly consisting of clay and claystone bedrock are expected to be encountered with swell potentials ranging from moderate to high. Significant overexcavation or soil remediation may be necessary at the site to prevent intolerable movement of structures and flatwork during or after construction. 3.2. TEST BORINGS AND LABORATORY SUMMARY Based on information obtained from the drilling operations and laboratory testing program, the general subsurface profile at this site consisted of loose and soft, alluvial clays and clayey sands overlying medium dense, poorly-graded sands with clay, with weathered claystone encountered at greater depths. Isolated areas of previously placed fill were encountered near boring B-3. Soil stratification, as shown on the boring logs, represents soil conditions at the specific boring locations; however, variations may occur between or beyond the borings. The stratification lines represent the approximate boundary between soil types, but the actual transition between soil layers may be gradual. Refer to the Boring Logs presented in Appendix B for specific soil profile descriptions and remarks. 3.3. SOIL PROPERTIES Alluvium (CL and SC) – Soft to stiff and very loose to medium dense, yellowish brown to brown, slightly moist to very moist, lean clay and clayey sand with varying sand and gravel contents. USCS Classification Dry Density (pcf) Moisture Content (%) Saturation (%) LL/PI (%) Unconfined Strength (tsf) (SPT “N” Values (bpf)) P-200 (% Passing #200) CL, SC 86.9 – 110.8 14.7 – 26.3 53.4 – 92.9 42 – 44/ 26 – 29 1.0 (2 – 12) 38.0 – 51.6 Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 5 Alluvium (SP-SC) – Medium dense to very dense, yellowish brown to brown, wet, poorly-graded sand with clay with varying gravel contents USCS Classification Dry Density (pcf) Moisture Content (%) Saturation (%) LL/PI (%) Unconfined Strength (tsf) (SPT “N” Values (bpf)) P-200 (% Passing #200) SP-SC N/A 10.1 – 12.6 N/A N/A N/A (11 – 50/5.5”) N/A N/A = Not Applicable Weathered Claystone –Very stiff to hard, yellowish brown to bluish gray, wet, weathered claystone with varying sand contents USCS Classification Dry Density (pcf) Moisture Content (%) Saturation (%) LL/PI (%) Unconfined Strength (tsf) (SPT “N” Values (bpf)) P-200 (% Passing #200) Claystone 98.9 – 111.4 12.5 – 23.6 58.6 – 65.7 38/23 4.1 (28 – 50/1”) N/A N/A = Not Applicable 3.4. GROUNDWATER SUMMARY Groundwater was encountered in all 6 borings completed during this exploration. Groundwater measurements obtained during drilling and immediately after drilling are presented in the following table: GROUNDWATER MEASUREMENTS Boring No. Groundwater depth while drilling (ft) Groundwater elevation while drilling (ft) Groundwater depth IAD (ft) Groundwater elevation IAD (ft) B-1 8.0 4942.0 7.1 4942.9 B-2 14.0 4936.0 13.7 4936.3 B-3 9.5 4940.5 10.5 4929.5 B-4 7.8 4942.2 7.6 4942.4 B-5 8.0 4942.0 7.8 4942.2 B-6 7.5 4942.5 7.1 4942.9 IAD = Immediately after drilling It should be noted that groundwater levels (perched or otherwise) typically fluctuate with seasonal variations in precipitation, runoff, snowmelt, irrigation demands, or other factors that may differ from those at the time of the drilling operations. Section 4.4 of this report addresses general groundwater or drainage concerns as applicable to the site design and earthwork as we now understand them. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 6 3.5. CORROSIVITY OF SOILS The results of the water-soluble sulfate, pH, chloride, and resistivity testing are summarized as follows: LABORATORY CHEMICAL TEST RESULTS Test/Sample Location Sulfate (mg/L) Relative Degree of Sulfate Attack Chloride (mg/L) pH Soil Resistivity (ohm-cm) B-1 (3 - 6’) 1100 Moderate 204 8.6 462 Laboratory test results from soils within the upper 3 to 6 feet indicate moderate risk of sulfate attack for concrete exposed to soils on this site. A mechanical/electrical designer, experienced with local building code requirements and local practice, should review the laboratory test results presented above and determine if corrosion protection of buried utility lines is required and how it is to be implemented. The use of Type V Portland cement, or an equivalent high sulfate resistant cement, is recommended where sulfate levels are greater than 1,500 parts per million (ppm) or in areas designated “Severe.” Type II is considered acceptable across areas of the site with sulfate levels less than 1,500 ppm but greater than 150 ppm or designated “Moderate.” Type I cement is considered acceptable across areas of the site with sulfate levels less than 150 ppm or designated “Negligible.” To help control superficial damage in concrete exposed to prolonged moisture or high groundwater, the water/cement ratio should not exceed 0.50. On-site soils have a moderate to high rating for corrosion of buried iron pipe. Refer to Appendix C, Summary of Laboratory Test Results for additional information. 3.6. EVALUATION OF ON-SITE SOILS Laboratory test results show that the onsite sandy clay soils have a low to moderate expansion and collapse potential, indicating 0.49 to 3.37 percent swell at inundation pressures of 200 to 1000 psf as shown in the table below. Based on the encountered soil conditions, conventional shallow spread footings and on-grade concrete floor slabs can be used to support the proposed structure, if constructed in accordance with the recommendations presented in this report. The pole sign(s) can be supported on drilled pier or shallow spread foundations if desired following the recommendations of this report. LABORATORY SWELL/COLLAPSE TEST RESULTS Test/Sample Location Material In-situ moisture (%) In-situ dry density (pcf) Inundation pressure (psf) Percent swell (+) or collapse (-) (%) Swell pressure (psf) B-2 @ 19.0’ Claystone 15.3 98.9 1000 +0.49 3100 B-5 @ 1.0’ Clayey Sand 14.7 110.8 200 +3.37 4800 B-6 @ 3.5’ Sandy Clay 18.6 86.9 500 +1.01 2000 Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 7 The magnitude of volume change of the soil depends on various factors including soil composition, in-situ moisture content, in-situ density, and the change in moisture content. Care should be taken to prevent as much surface water infiltration into the subsurface materials as possible to reduce the swell or collapse potential. The on-site materials are suitable to support shallow building foundations. Bearing soils loosened at the bottom of the footing excavations should be removed or compacted prior to placement of structural fill, reinforcing steel, and concrete. Subgrade soils at the base of foundation excavations should be firm and unyielding. The use of a smooth cutting edge on the excavator bucket will help reduce subgrade disturbance at the base of foundation trenches. Based on laboratory testing results from areas sampled during this exploration, the onsite clays and sandy soils are suitable for reuse as structural fill, provided they are properly moisture conditioned and compacted as recommended in Section 4.2. An Olsson representative should be present at the time foundations are excavated to document the soil conditions encountered are consistent with those identified during this exploration. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 8 SITE PREPARATION 4.1. GENERAL SITE PREPARATION At the time of drilling, the site was occupied by a gas station/convenience store in the northeast corner and single-story homes and outbuildings around the remainder of the property. All existing buildings, structures, and pavements will be razed and removed during the Kum & Go redevelopment. The demolition contractor should consider leaving the existing pavements in place during demolition operations to help prevent unnecessary disturbance of or damage to the existing subgrade soils. Surface cover also included new and old growth trees and shrubs in unpaved areas. Vegetation, trees, shrubs, topsoil, pavements, demolition debris, and other deleterious material should be removed from areas of new construction. Existing vegetation and topsoil should be stripped to a depth of 6 to 8 inches and removed from the site or stockpiled for later use in landscaped or other non-loaded areas. Some areas may require stripping to slightly greater depths. Excavations created during the removal of trees and their root balls should include the removal of roots larger than 1-inch in diameter. If requested, an Olsson representative can help determine final stripping depths in areas of concern. Although our soil borings were completed near existing buildings or structures wherever possible, the soil conditions directly below these existing features are unknown. Due to existing structures and limited drill rig access, some borings could not be completed at the locations of future structures. Although the subsurface soils encountered in our borings were consistent across the site, the recommendations of this report are based on our anticipation that soil conditions directly below existing buildings and structures are also similar to those encountered in our widely spaced borings. Olsson should be notified if differing conditions are encountered during construction. We recommend that an Olsson representative be present at the time of demolition to observe and document soil conditions below existing buildings and site features. All foundations, floor slabs, sign, and utility lines below future Kum & Go structures and pavements should be completely removed or relocated with the trenches or excavations backfilled with structural fill following the recommendations of this report. Excavations created during demolition or tree/shrub removal should be cleaned of debris, unsuitable materials, and loose soils and made wide enough to allow for proper backfill and compaction. We recommend that field observations and documentation of moisture contents and compaction be completed by Olsson representatives within all excavations or trenches at the time of demolition and during backfilling activities. For this site, we recommend the floor slab be supported by a minimum 36 inches of new structural fill or 36 inches of on-site native soils prepared as structural fill. To achieve this compacted structural fill thickness, the building footprint and an area extending 10 feet around the building Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 9 should be overexcavated to a depth of 24 inches below final grade, the resultant subgrade should then be scarified to a depth of 12 inches and prepared in accordance with this report. Site clearing, grubbing, and stripping should be completed during periods of dry weather. Operating heavy equipment on the site during periods of wet weather could result in excessive pumping and rutting of the subgrade soils. The base of new construction excavations should be evaluated by an Olsson geotechnical engineer or their authorized representative prior to placing new fill soils. New structural fill should be placed and compacted in accordance with the recommendations presented in Section 4.4. Prior to new structural fill placement, the contractor should scarify the upper 12 inches of resultant subgrade, moisture condition as necessary, and compact the subgrade soils in accordance with this report. After the subgrade has been compacted, areas to receive new structural fill should be proofrolled with a loaded tandem axle dump truck or similar rubber-tired equipment weighing at least 20 tons. The engineer may also evaluate the surface soils using a hand-operated “T- Probe” or by dynamic cone penetrometer testing. Proofrolling operations should be observed and documented by an Olsson field representative. Unstable or unsuitable soils which are revealed by proofrolling or by T-probe evaluation and which cannot be adequately densified in-place should be documented, removed, and replaced with new compacted structural fill placed under the direction of the geotechnical engineer. If unstable subgrade conditions are present, the geotechnical engineer may include driving multiple, thin lifts of coarse crushed stone, 2- to 3-inch diameter, into the subgrade. As an alternative, the engineer may also suggest the use of geosynthetic grid, such as Tensar BX-1100, underlying 6 to 10 inches or more of 1¼-inch minus crushed stone or crushed recycled concrete. If requested, the geotechnical engineer can help determine an applicable and cost-effective approach for improving subgrade stability as soil conditions dictate. 4.2. STRUCTURAL FILL All imported structural fill soils should be relatively free of organics (less than about 2 percent by weight) or other deleterious material and should not contain particles larger than 3 inches. Prior to delivery, laboratory property and swell testing should be completed to document that the materials meet the requirements of this report for imported structural fill. Continuous monitoring of laboratory properties and swell results for all imported fill materials will also be required during the earthwork operations. Based on the results of our subsurface exploration, the on-site clay and clayey sand alluvial soils removed from the UST excavation appear suitable to be reused as structural fill at the site. If the poorly-graded sand are encountered during construction and the contractor desires to use it as new fill materials, the geotechnical engineer should be contacted. Claystone should not be reused as fill or backfill on this site. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 10 Imported fill materials, if required, should be low plasticity, non- or low-expansive, cohesive material with a liquid limit less than 45, a plasticity index less than 25, having at least 25 percent passing the #200 sieve, and having a maximum swell potential of 1.0 percent. If alternate borrow materials are considered, we recommend the contractor provide supplier gradation and/or laboratory plasticity and swell documentation to Olsson for review and approval prior to site delivery. Additional laboratory testing and documentation by Olsson geotechnical engineers will be required prior to the consideration or acceptance of imported fill materials. Suitable fill materials should be placed in thin lifts. Lift thickness depends on the type of compaction equipment, but in general, lifts of 4 to 8-inch loose measurement are recommended. Soils should be compacted using equipment of appropriate size and type to achieve the requirements of this report. . A self-propelled, smooth drum roller is generally recommended for compacting cohesionless soils while a self-propelled, vibratory sheepfoot roller is generally recommended for compacting cohesive soils. A loose lift thickness of 6 inches is suggested for compaction procedures. Wheel rolling using rubber-tired equipment is not an acceptable method of compaction and should not be allowed. Within small excavations, such as in footing trenches, utility trenches, or around manholes, “Wacker-Packers” or “Rammax” compactors for cohesive soils or vibrating plate compactors for granular soils (where allowed by the geotechnical engineer) can be used to achieve the specified compaction. Lift thicknesses should be reduced to 4 inches in small fill areas requiring hand-operated equipment. To achieve proper compaction of granular cushion materials, the stone should have the individual stone facets properly oriented using a plate compactor, jumping jack, or other vibratory compaction device. During grading operations, representative samples of general and structural fill materials should be initially and periodically checked via laboratory property to document that the previously mentioned soil parameters are maintained. A full-time Olsson representative should be on-site during all earthwork operations to observe and monitor the excavation and grading operations and perform field density tests and obtain samples for laboratory swell testing to document that the specified moisture and compaction requirements are being achieved and that swell limits are being maintained. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 11 FILL PLACEMENT/COMPACTION GUIDELINES Areas of Fill Placement Minimum Compaction (ASTM D698 Standard Proctor) Moisture Content (Percent of Optimum) Structural Fill – On-site or imported soils placed below and within 10 feet of the building, structures, or pavements 95% -2 to +2 percent for approved cohesionless soils Or -1 to +3 percent for non- expansive, approved cohesive fill soil Floor Slab Subgrade – Structural fill placed below the building floor slab or below the granular cushion layer, if utilized. 95% Utility Trenches – Cohesive structural fill soils placed within new utility trenches 95% Granular Cushion Layer – Beneath floor slab N/A* Pavement Subgrade – Imported structural fill soils below areas of new pavement 95% Sidewalk Subgrade – Below grade-supported sidewalks 95% Non-Structural Fill – Beneath non-loaded landscape/grass areas 92% *Visual observation of compactive effort by the geotechnical engineer The moisture content for imported fill soils at the time of compaction should generally be maintained between the ranges specified above. More stringent moisture limits may be necessary with certain soils, and some adjustments to moisture contents may be necessary to achieve compaction in accordance with project specifications. 4.3. UTILITIES New underground utilities should be installed in accordance with local building codes. Utility trench backfill should consist of compacted structural fill placed in accordance with Section 4.2 of this report. Where utilities will penetrate the footprint of the building, it is recommended that a utility trench “plug” be constructed that extends at least 5 feet beyond the building perimeter. The trench plug should consist of non-expansive backfill materials having at least 50 percent passing the #200 sieve, to provide a moisture barrier to the soils within the influence zone of the new building. In addition, flexible connections should be used wherever possible. Granular pipe bedding for new utilities is acceptable, but the remaining trench should be backfilled, placed, and compacted as structural fill using acceptable native soils originally removed from the trench or approved imported soils. Water should be prevented from entering utility trenches before, during, and after construction. Excavations should not remain open if rain is anticipated. Excavations should be backfilled as soon as possible with approved structural fill to reduce the potential for moisture infiltration or sidewall sloughing. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 12 4.4. DRAINAGE AND GROUNDWATER CONSIDERATIONS Groundwater was encountered in all borings at depths ranging from 7.1 to 14.0 feet during this exploration. Considering these depths, groundwater or saturated soil conditions are not anticipated to impact site grading, earthwork, shallow building construction, or shallow utility installation. However, groundwater should be anticipated during the installation of drilled shaft foundations, the removal of existing UST’s, and the installation of new UST’s. Water should not be allowed to collect near foundations, floor slabs, or in areas of new pavements, either during or after construction. As applicable, provisions should be made to quickly remove accumulating seepage water or storm water runoff from excavations. Undercut or excavated areas should be sloped toward one corner to allow rainwater or surface runoff to be quickly collected and gravity drained or pumped from construction areas. Subgrade soils that are exposed to precipitation or runoff should be evaluated by the geotechnical engineer prior to the placement of new fill, reinforcing steel, or concrete, to determine if corrective action is required. To minimize concerns related to improper or inadequate drainage away from foundation bearing subgrades or from cohesive backfill materials used in utility or foundation trenches, we provide the following general recommendations: · Site grading should provide efficient drainage of rainfall or surface runoff away from new structures and pavements. · Roof drains from the new building and canopy should be collected and discharged directly to the storm sewer or directed to a down gradient location away from structures and pavements. · External hose connections in unpaved areas should incorporate splash blocks to prevent localized flooding of foundation bearing or backfill soils. External hose connections should have cut-off valves inside the building to prevent accidental or unauthorized use. · Maintenance personnel should be informed of the potential concerns associated with excessive watering near the building. Relative uncertainty exists with short interval groundwater measurements, and groundwater may fluccuate seasonally or with precipitation events. If surface runoff or groundwater are encountered, the contractor should be prepared for localized dewatering and pumping techniques to remove water from excavations. The design, operation, and maintenance of the dewatering system during construction is the responsibility of the contractor. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 13 4.5. CONSTRUCTION EQUIPMENT MOBILITY On-site or imported soils may be susceptible to softening under construction equipment traffic during periods of wet weather. Reducing equipment mobility problems and managing soft surface soils will be dependent on the severity of the circumstances, the soil types, the season in which construction is performed, and prevailing weather conditions. Some general guidelines for reducing equipment mobility problems and addressing potential soft and wet surface soils are as follows: · Optimize surface water drainage at the site during construction. · Whenever possible, wait for dry weather conditions to prevail and do not operate construction equipment on the site during wet conditions. Rutting the surface soils will aggravate the condition and accelerate subgrade disturbance. · Disk or scarify wet surface soils during periods of favorable weather to accelerate drying. Temporarily compact loose subgrade soils if rain is forecast to promote site drainage and reduce moisture infiltration. · Use construction equipment that is well-suited for the intended job under the existing site conditions. Heavy rubber-tired equipment typically requires better site conditions than light, track-mounted equipment. · Implement a construction schedule that realistically allows for rain days. Pressure to perform earthwork under a tight schedule is frequently counterproductive. If requested, Olsson can help determine a cost-effective approach for stabilizing unsuitable soils based on actual site conditions at the time of construction. 4.6. TEMPORARY SLOPES AND EXCAVATIONS Construction site safety is the responsibility of the general contractor. The contractor shall also be solely responsible for the means, methods, techniques, sequencing, and operations during construction. Olsson is providing the following information solely as a service to EES. Under no circumstances should Olsson’s provision of the following information be construed to mean that we are assuming responsibility for construction site safety or the contractor’s activities. Such responsibility is not implied and should not be inferred. The contractor should be aware that slope height, slope inclination, and excavation depths (including utility trench excavations) should in no case exceed those specified in local, state, or federal safety regulations, e.g., OSHA Health and Safety Standards for Excavations, 29 CFR Part 1926, or successor regulations. Such regulations are strictly enforced, and if not followed, the owner, the contractor, or earthwork or utility subcontractors could be liable for substantial Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 14 penalties. The contractor is responsible for reviewing this geotechnical report, determining the appropriate OSHA slope criteria for the soil conditions encountered, and implementing it during construction. Soils encountered in construction excavations may vary significantly across the site. Our preliminary soil classifications are based solely on the materials encountered in the widely spaced borings. The contractor should verify that similar soil conditions exist throughout the proposed areas of excavation. If different subsurface conditions are encountered at the time of construction, Olsson recommends that they be contacted to re-evaluate existing site conditions. Temporary slopes steeper than 5H:1V should be properly benched prior to placement of new fill. As an alternative to flatter and benched temporary slopes, vertical excavations can be temporarily shored. The contractor should be responsible for the design of temporary shoring in accordance with applicable regulatory requirements. Permanent fill and cut slopes at the site should not exceed 3H:1V. Where steeper slopes are planned, additional analysis should be performed once grading plans have been developed. Stockpiles of soils and equipment should not be placed within a horizontal distance equal to one- half the excavation depth, from the edge of the excavation. A professional engineer should design excavations deeper than 20 feet. If excavations, including utility trenches, are extended to depths of more than 20 feet, OSHA requires that the side slopes of such excavations be designed by a professional engineer registered in the state where construction is occurring. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 15 BUILDINGS AND STRUCTURES 5.1. SHALLOW FOUNDATION DESIGN The native soils appear suitable for supporting the lightly loaded Kum & Go building on conventional shallow foundations. Boring B-2 was potholed to a depth of 5 feet and backfilled with pea gravel by another contractor prior to Olsson’s arrival on-site. The lateral extents of the potholed area are unknown. Although this pothole location may be outside the footprint of the future Kum & Go building, we recommend this dissimilar backfill material be completely removed and replaced with compacted structural fill following the recommendations of this report. The base of the foundation excavations should be observed and documented to be suitable to provide a stable and uniform bearing surface by a geotechnical engineer or authorized representative. Shallow spread or trench type foundations bearing on new structural fill or native soils prepared as structural fill may be designed using a net allowable soil bearing pressure of up to 2,500 pounds per square foot (psf). The net allowable bearing capacity can be increased by 1/3 for transient loadings (short term loading such as wind load or seismic load) when used with the alternative basic load combinations of Section 1605.3.2 of IBC 2015. These design recommendations are based on the anticipated maximum structural loads noted in Section 1.3 of this report. Bearing soils loosened at the bottom of the footing excavations should be removed or compacted prior to placement of structural fill, reinforcing steel, and concrete. Subgrade soils at the base of foundation excavations should be firm and unyielding. The use of a smooth cutting edge on the excavation bucket will help reduce subgrade disturbance at the base of foundation trenches. Building footings should have minimum dimensions in accordance with local building codes. Olsson recommends minimum dimensions of 18 inches for continuous footings and 24 inches for isolated column footings to minimize the potential for localized bearing failure. Perimeter footings and footings in unheated areas should bear at a minimum depth of 30 inches below the lowest adjacent final ground surface for frost protection per Larimer County requirements. As long as subgrade soils and foundation bearing conditions meet, or have been prepared to meet, the recommendations of this report, interior footings in heated areas can bear as shallow as necessary below the floor slab or below the granular cushion layer unless this recommendation is superseded by the design engineer or City or County regulations. Prepared foundation subgrades should still be observed by an Olsson geotechnical engineer or his/her authorized field representative prior to placing reinforcing steel or concrete to document that the subgrade soils and conditions are consistent with the bearing subgrade requirements of this report. The total post-construction movement for the new Kum & Go building with foundations less than 5 feet wide, designed and constructed as recommended above is anticipated to be less than 1- Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 16 inch with differential movement limited to less than ½-inch over 50 feet or between adjacent columns. To reduce the effects of differential settlement, floating floor slabs with expansion joints, independent from wall and column loads, will be important in minimizing the potential cracking that can occur along and around foundation systems. Floor slab control joints should be used to reduce potential damage due to shrinkage cracks. Lateral resistance of the foundations will be achieved through a combination of base shear resistance mobilized at the footing-subgrade interface and passive earth pressure acting on the vertical faces of the footings at right angles to the direction of applied load. A friction coefficient value of 0.4 can be used between the native soil or structural fill and the foundation concrete for base shear and sliding resistance. Passive earth pressure resistance can be calculated using parameters provided in Section 5.6. For foundations subjected to both uplift and lateral forces, the base friction should be neglected in the calculations. The uplift resistance for the shallow foundation is developed by the dead load at the footing, and the weight of the soil directly above the footing. The weight of the soil can be calculated using a unit weight of 115 pcf and the volume of a prismatic failure block with vertical faces above the footing edges. After foundation subgrades have been observed and evaluated by an Olsson representative, concrete should be placed as soon as possible to avoid subjecting the exposed soils to drying, wetting, or freezing conditions. If foundation subgrade soils are subjected to such conditions, the geotechnical engineer should be contacted to reevaluate the foundation bearing materials. It will not be acceptable for the contractor to place lean concrete, flowable fill, or other types of “mud mat” below shallow foundations unless specifically directed by the geotechnical engineer. 5.2. MONUMENT SIGN/DEEP FOUNDATION DESIGN Based on the results of our exploration, the native soils appear to be suitable for the support of shallow foundations if they are selected for the monument sign in the northeast corner of the site. Based on our exploration, the shallow foundations would bear in the alluvial lean clay with varying sand contents. The upper 12 inches of subgrade at the bottom of the excavation should be moisture conditioned and recompacted to 95% of the materials standard proctor maximum dry density to provide a stable and uniform bearing surface. Shallow spread or trench type foundations bearing on new structural fill, native soils prepared as structural fill may be designed using a net allowable soil bearing pressure of up to 2,500 pounds per square foot (psf). The following L-pile parameters can be utilized if drilled shaft foundations are chosen for the monument sign. Considering the soil conditions anticipated near a future pole sign, borings for drilled shaft foundations should stand unsupported during installation. If designing a drilled shaft foundation for a pole sign using LPILE v2012 by Ensoft Inc., the following parameters are Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 17 applicable. The deep foundation design parameters are based on the results of the laboratory testing program and soil information from boring B-2. · Olsson recommends that the drilled shaft foundation be a minimum of 18 inches in diameter, end bear at a minimum depth of 18 feet on or within the hard weathered claystone formation and be designed in accordance with the soil parameters provided below. We recommend the drilled shaft foundations be designed using a minimum factor of safety of 2 for both side friction and end bearing. The final shaft diameter and tip depth should be determined and provided by the structural engineer or sign manufacturer based on their review of this report and the soil conditions encountered at the time of installation. L-PILE PARAMETERS FOR DRILLED SHAFT DESIGN (BORING B-2) Soil Type Approximate Formation Depths (ft) Ultimate Skin Friction (no FS) (psf) Ultimate End Bearing (no FS) (psf) Static Lateral Modulus K (pci) Strain Factor E50 Stiff, lean clay backfill (CL) (Frost Zone)* 0 – 2.5 N/A N/A N/A N/A Stiff, lean clay backfill (CL)* 2.5 – 5.0 750 N/A 100 0.01 Firm, lean clay alluvium (CL) 5.0 – 9.7 400 N/A 30 0.02 Medium dense, poorly- graded sand with clay alluvium (SP-SC) 9.7 – 18.0 1,500 N/A 60 0.007 Hard, weathered claystone 18.0 – 24.3 2,500 15,000 2,000 0.004 N/A = Not Applicable *Assuming original pea gravel is removed and replaced as recommended in the report. · An uplift capacity equal to 75 percent of the allowable skin friction resistance can be used in combination with the overall pile weight for the design of a steel reinforced pile and uplift calculations. The structural capacity of the pile should be determined using applicable building codes. · Drilled shafts required to resist uplift forces must be reinforced over their entire length. It is common for drilled shaft foundations to be designed with sufficient reinforcing steel to accommodate incidental bending moments and transient lateral loads. Typically, the reinforcing steel area requirement is equal to about 1 percent of the pile cross-sectional area. A distance equal to the pile diameter should be neglected at the base of the drilled shaft for side friction calculations to account for the side friction and end bearing interaction that occurs at the tip of the shaft. · Construction specifications for drilled shafts should include a concrete mix designed to Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 18 limit bleeding of installed piles and the pile contractor’s responsibility to increase individual or group pile lengths or the installation of additional piles to compensate for any soil disturbance created by the contractors mean and methods during construction. The concrete or grout mix, at a minimum, should be designed to achieve a 28-day compressive strength of 4,000 psi. · The use of water to aid in drilling the shaft is not allowed. · An Olsson field technician should be on site to observe and document the shaft boring as it is drilled and during concrete and reinforcing steel placement. · The base of the drilled shaft should be clean and free of debris or loose soil prior to placing concrete or reinforcing steel. Concrete for the pile foundation should be placed promptly to reduce exposing the subsoils to rain, surface runoff, or drying conditions. If foundation bearing soils are subjected to such conditions, the soils should be reevaluated by an Olsson representative prior to reinforcing steel or concrete placement. · Soil conditions at the time of drilling indicated that boring sidewalls should stand unsupported during drilled shaft installation. Contractors should carefully review this geotechnical report and evaluate their means and methods accordingly based on their experience with local soils and subsurface conditions. · We recommend that concrete for drilled shaft foundations have a slump of 5 to 7 inches at the time of placement. A bottom dump hopper or tremie pipe could be considered to prevent concrete from contacting the boring sidewall and potential aggregate segregation. If encountered, surface runoff or groundwater at the bottom of the shaft boring should be removed by pumping prior to concrete grout placement. 5.3. SEISMIC CLASSIFICATION Per the International Building Code (IBC), soils within the upper 100 feet determine the seismic structural design criteria for the project site. The soil shear strengths and blow counts (N values) were estimated based on the results of the laboratory testing program, field exploration, and the assumed soil properties on the undocumented soils below the lowest boring. For this project site, we recommend using a Site Class D (stiff soil profile) in accordance with 2015 IBC. This recommendation is based on the soil conditions encountered in the borings during the exploration and our assumption that the encountered soils continue beyond the drilled depth to the full 100 feet. A seismic survey to 100 feet depth could be performed if the design engineers require a more site-specific seismic classification. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 19 5.4. FLOOR SLAB DESIGN A concrete slab-on-grade floor system appears feasible for the future Kum & Go building if supported by a specific thickness of compacted structural fill. For this site, we recommend the floor slab be supported by a minimum 36 inches of new structural fill or 36 inches of on-site native soils prepared as structural fill. To achieve this compacted structural fill thickness, the building footprint and an area extending 10 feet around the building should be overexcavated to a depth of 24 inches below final grade, the resultant subgrade should then be scarified to a depth of 12 inches, moisture conditioned as necessary, and compacted to a minimum 95% of the materials Standard Proctor maximum dry density per Sections 4.1 and 4.2. The typical 4-inch granular cushion thickness provided below Kum & Go floor slabs is not to be included in the 36-inch compacted structural fill thickness. We recommend a free draining, 4-inch thick granular leveling and drainage course consisting of No. 57 stone meeting ASTM C-33 specifications, or equivalent, be installed beneath the concrete floor slab above the newly placed structural fill for uniform support and to act as a capillary break. Additionally, the floor slab subgrade should be evaluated by proofrolling (if feasible) with an Olsson representative present, during the site grading or earthwork stages. If unstable soils are encountered which cannot be adequately densified in place, these soils should be removed and replaced with structural fill in accordance with the recommendations of this report. Lightly loaded interior partition walls (applying less than 0.75 klf) may be supported directly on the slab on grade floor. Although depending on the floor slab design and the specific wall loads, it may be appropriate to increase the floor slab reinforcement or provide a thickened slab cross section below interior walls. For interior walls with loads greater than 0.75 klf, Olsson recommends that a footing be installed, independent from the floor slab, to properly distribute the wall loads to the underlying soil and reduce the potential for floor slab damage. If these recommendations are followed and the subgrade soils are prepared and compacted as recommended, the building floor slab may be designed using a subgrade modulus (“k” value) of 110 psi/in. Based on our experience with other Kum & Go projects, it may be appropriate to provide a sealed polyethylene vapor barrier between the new floor slab and granular drainage materials to reduce moisture infiltration. The decision to place a vapor barrier in direct contact with the slab or beneath the layer of granular fill should be made by the design engineer after considering the moisture sensitivity of new flooring materials or finishes and installed per the current American Concrete Institute standards and recommendations. Slab performance is greatly dependent on the amount of moisture introduced to the underlying soils, which could result in excessive movement causing uneven slabs and cracking. Proper subgrade preparation and surface grading will help to reduce water infiltration into the prepared and documented structural fill soils. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 20 5.5. EXTERIOR SLABS AND SIDEWALKS Considering the encountered conditions during our exploration below and around the building footprint, the standard Kum & Go “turn-down” design for approach and entrance slabs should be appropriate. The standard Kum & Go design for exterior sidewalks adjacent to the building includes 12 inches of compacted crushed aggregate directly below the slabs. Refer to the applicable Kum & Go construction or design drawings for specific details. To minimize future moisture accumulation within this granular layer, providing a panel or trench drain extending to a gravity discharge point away from the building or pavements could be considered. At a minimum, we recommend regularly scheduled crack and joint sealing between slabs, pavements, and the building to reduce potential moisture infiltration. Olsson recommends that new sidewalks located away from the Kum & Go building be supported by a minimum 24 inches of compacted subgrade soil. This recommendation can be achieved by placing 12 inches of documented compacted structural fill or native soils prepared as structural fill over 12 inches of scarified, moisture conditioned, and compacted native soils within the sidewalk subgrade, moisture conditioning as necessary, and compacting to a minimum 95 percent of the materials Standard Proctor maximum dry density at the applicable materials moisture content provided in Section 4.2. Prepared subgrades should extend a minimum of 1-foot beyond each edge of sidewalk, where feasible. Improper subgrade preparation such as inadequate vegetation removal, failure to identify soft or unstable areas, and inadequate or improper compaction can also produce non-uniform subgrade support and cause unacceptable post-construction movement. Additionally, subgrade soils consisting of clay, including the native soils encountered on site, could be frost susceptible. If these soils become very moist or saturated and freeze, slab heaving is possible. Positive grading to direct surface drainage away from sidewalks will help limit the potential for moisture infiltration of slab subgrade soils and subsequent frost related heaving. At a minimum, we recommend regularly scheduled crack and joint sealing between slabs, pavements, and the building to reduce potential moisture infiltration. 5.6. LATERAL EARTH PRESSURES The following soil parameters are provided for use in designing foundation or below grade retaining walls which are subjected to lateral earth pressures. The maximum toe pressure for below grade walls should not exceed the bearing capacity recommended in this report for shallow spread foundations. The parameters are based on the understanding that retained soils will be similar in composition to the on-site soils encountered during this exploration. The effects of lateral earth pressure should be considered during selection of the underground fuel tank. Walls which are rigidly restrained at the top and are essentially unable to deflect or rotate should be designed for “at rest” earth pressure conditions. Walls that are unrestrained at the top and are Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 21 free to deflect or rotate slightly may be designed for “active” earth pressure conditions. The “passive” earth pressure condition should be used to evaluate the resistance of soil to lateral loads. Equivalent fluid densities are provided in the table below, which are frequently used for the calculation of lateral earth pressures for the “at rest” and “active” conditions. The equivalent fluid densities below do not include the effects of surcharge loading. EARTH PRESSURE PARAMETERS Condition Soil Type Equivalent Fluid Density* Moist Condition Saturated Condition** Active (Ka) Low plasticity cohesive materials 45 pcf 85 pcf Cohesionless granular materials 40 pcf 80 pcf At Rest (K0) Low plasticity cohesive materials 65 pcf 95 pcf Cohesionless granular materials 60 pcf 90 pcf Passive (Kp) Low plasticity cohesive materials 345 pcf 235 pcf Cohesionless granular materials 400 pcf 265 pcf * Assumed level backfill. **Saturated equivalent fluid density values include hydrostatic pressure. Value would need to be adjusted if water is above ground surface. These design recommendations are based on the following assumptions: · For active earth pressure, the wall must rotate about its base, with top lateral movements 0.002 Z to 0.004 Z (granular) or 0.010 Z to 0.020 Z (clays), where Z is wall height. This is necessary to allow the active condition to develop. · For passive earth pressure, the wall must rotate about its base, with top lateral movements 0.020 Z to 0.060 Z (granular) or 0.020 Z to 0.040 Z (clays), where Z is wall height. This is necessary to allow the passive condition to develop. · Drained condition requires the walls have a permanent drainage system behind the wall that will prevent hydrostatic pressure from developing. Moisture collected in the drain system should be collected in a sump pit and pumped away from the structure or daylight to a location that will gravity drain. If permanent drainage is not provided, undrained condition should be used for design. · The soil parameters provided above assume the backfill is level with the top of the wall. If a sloping backfill is utilized, the parameters will need to be reevaluated. In addition to a sloping backfill, the walls should be designed to resist surcharge loads, including nearby shallow foundations or other concentrated load components and traffic loads. Passive pressures are typically lower if the ground surface slopes downward away from the face of the wall. · Passive resistance against horizontal movement within frost zone should be ignored. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 22 · Backfill soils placed within the height of the retained wall should consist of well compacted selected granular soils or low-plasticity non-expansive cohesive soils. The cohesive soils should be tested to verify these soils can achieve a minimum friction angle of 28 degrees and a unit weight of 125 pcf. Backfilled granular materials should have a minimum friction angle of 32 degrees and a unit weight of 125 pcf. For the values to be valid, the backfill must extend out from the base of the wall at an angle of at least 45 and 60 degrees from vertical for the active and passive cases, respectively. · Uniform surcharge, heavy equipment and other concentrated load components are not included. · Factor of safety is not included. The designer should use appropriate factors of safety for design. · To calculate the resistance to sliding on native soil, a coefficient of friction value of 0.40 should be used where the footing is supported by engineer-approved bearing soil consisting of sandy clay soils or similar structural fill. A factor of safety of at least 1.5 should be applied to sliding calculations for the overall wall design. 5.7. UST EXCAVATION AREAS – EXISTING We understand one or more UST’s may still be present near the former gas station/convenience store at the northeast corner of the site. If still present, we understand these UST’s will be removed per State of Colorado guidelines. Typically, when UST’s are removed, the remaining backfill materials are poorly compacted and will require either complete removal and replacement or partial removal, rework, and replacement with compacted structural fill. Considering the location of the existing UST’s, a portion of the future Kum & Go building foundations may extend directly over or very near the old UST excavation. Proper backfilling of the old UST excavation will be required to provide adequate support for the future building foundations, floor slab, and adjacent pavements. Option 1 This option does involve some risk of future building movement, but if the procedures provided in this report are followed and documented, the risk of future building movement should be controlled to tolerable structural limits. Additional field observation and documentation by Olsson engineers at the time of the UST removal is recommended to determine if the soil, backfill, and groundwater assumptions in this report are consistent with those encountered at the time of removal/construction. Depending on the extent of the old UST excavation relative to the new building foundations and groundwater elevation at the time of removal, it may be feasible to remove groundwater within the excavation to a minimum depth of 8 feet below FFE. The use of one or more sump pits and automatic pumps should be suitable for maintaining a dry working area within the UST excavation. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 23 After the groundwater is removed, the existing backfill materials should be removed to a minimum depth of 6 feet below FFE, or 3 feet below the base of new foundation elevations. At this elevation, the contractor should utilize a backhoe mounted, heavy duty vibro-plate compactor to thoroughly densify the pea gravel backfill remaining in the excavation. Groundwater must be maintained a minimum of 2 feet below the base of the compacted pea gravel surface during the initial compactive effort. An Olsson geotechnical engineer must be present during the UST removal and backfilling operations to document that the recommendations of this report are achieved. After approval from the Olsson engineer is received, the contractor should then place a single layer of Tensar BX1200 geogrid across the entire compacted pea gravel surface and extend it a minimum 18 inches up the excavation sidewalls on all sides. The contractor should then place a uniform 6-inch lift of well graded, 1½-inch minus crushed limestone into the excavation and compact it using the backhoe mounted vibro-plate or the heavy duty, hand operated vibro-plate compactor. No specific in-situ compacted density of the crushed aggregate is required at this time, although an Olsson geotechnical engineer must be present to observe and document that adequate compactive effort was provided by the contractor. A second 6-inch lift of crushed aggregates should then be placed following the same procedures. Assuming a safe excavation for our field technicians is provided, field compaction and documentation of the crushed aggregates should begin for each subsequent 12-inches (2 compacted 6-inch lifts) of compacted aggregate. We recommend the crushed aggregates be compacted to a minimum 98% of the materials maximum Standard Proctor dry density. These backfilling and compaction processes should continue until the base of the excavation reaches an elevation 18 inches below the base of the Kum & Go building foundation. An additional layer of Tensar geogrid should be placed followed by subsequent 6-inch lifts of compacted aggregates up to the base of foundation elevation. At this elevation, the contractor could consider switching to cohesive backfill materials up to design grade which will help prevent future moisture infiltration into the old UST excavation and allow the use of conventional trench foundations for the new building. Compaction testing and documentation of all new cohesive structural fill materials on a full-time basis by an Olsson geotechnical representative or his authorized representative, following the recommendations of this report, are required below and around the future Kum & Go building and pavements. Unless environmental limitations prevent the reuse of excavated UST backfill materials, they may be suitable for reuse as backfill during the installation of the new UST’s. Likewise, some materials excavated from the new UST location may be suitable for reuse as backfill within the old UST excavation. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 24 Option 2 Option 2 involves complete removal of the existing surface materials and pea gravel backfill from the old UST excavation and replacing it with full-depth structural fill following the recommendations of this report. Considering the potential shallow groundwater elevation, crushed aggregates may be used as backfill for the old UST as long as the base of excavation elevation remains at least 2 feet higher than the current groundwater elevation during placement. Above groundwater elevation, cohesive structural fill can be moisture conditioned, placed, and compacted following the recommendations of this report. If Option 2, full-depth backfill removal and replacement, is considered, future structure settlement will be controlled to typical Kum & Go building limits. 5.8. UNDERGROUND FUEL TANKS - NEW Due to site conditions, a geotechnical boring could not be completed in the location of the future USTs. The subsurface soils in the borings completed during this exploration appeared to be consistent, so for the purpose of this report Olsson assumed the subsurface conditions in the UST location will be similar to the soils in B-5 and B-6. Olsson should be notified if differing conditions are encountered during construction. Based on the sandy soils that were encountered within the borings, shoring or benching within the proposed UST excavation should be anticipated to protect the roads, adjacent utilities, or adjacent properties from disturbance or loss of support during excavation or backfilling operations. The native soils appear suitable to support the USTs and associated components. Based on our laboratory results, clay and clayey sand alluvial soils removed from the UST excavation appear suitable to be reused as structural fill at the site. If the poorly-graded sand are encountered during UST installation and the contractor desires to use it as new fill materials, the geotechnical engineer should be contacted. Claystone should not be reused as fill or backfill on this site. · Excavated native soils and the overlying imported structural fill materials should be replaced with approved backfill of proper size and gradation. Granular backfill materials should meet ASTM C-33 requirements for quality and soundness. · Backfill suppliers should provide sieve analysis documentation that the materials meet these requirements. · Backfill materials should be kept dry and free of ice or snow in freezing conditions. Typical backfill material for new fuel tank installation consists of free-draining naturally rounded aggregates (pea gravel) with a maximum ¾-inch particle size and no more than 5 percent passing a #8 sieve. Crushed and washed stone with a maximum angular particle size of ½ inches and no more than 5 percent passing the #8 sieve can also be used. If material which meets these typical specifications is not locally available, the tank manufacturer should be contacted for information Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 25 or approval of alternate materials and installation instructions. Tank backfill materials should be compacted carefully to prevent tank damage; however, if new pavements will cover the backfill materials, adequate compactive efforts must be applied to prevent future settlement and pavement damage. If new pavements will be placed over the new underground fuel tanks, we recommend that the backfill be compacted to a minimum 95 percent of the materials Standard Proctor (ASTM D-698) maximum dry density. These backfill recommendations are provided as a general guideline for underground fuel tank applications. They are not intended to supersede the material recommendations or installation requirements of a specific tank manufacturer. We recommend that the manufacturer’s recommendations be reviewed and followed, as appropriate, for the surface covering proposed, the tank type selected, and the site conditions anticipated by the installation contractor. In addition, since the UST is close to an overhead canopy, the excavations for the UST will affect the canopy and vice versa; therefore, the UST installation contractor and the canopy contractor should coordinate their excavation and construction activities. Groundwater was encountered in all 6 borings during our exploration. Consequently, groundwater or saturated soil conditions should be anticipated during site grading, earthwork, or construction of the shallow building foundations, underground fuel tanks, utilities, or drilled shaft foundations. If free water is encountered during the tank excavation and subgrade preparation, the contractor should follow an applicable local and state dewatering plan. The installation contractor is responsible for the design of shoring or benching of excavation sidewalls as applicable for his selected means and methods. The native soils encountered across a majority of the site included clayey sand and poorly graded sand with clay at depths typically extending to the termination depths. Five of our geotechnical borings caved immediately following drilling, indicating excavation sidewalls may potentially be unstable and could cave in during UST installation. The excavation and UST installation contractor should be aware of this. The contractor should review this report thoroughly and determine if shoring or benching of the excavation sidewalls are applicable and select his means and methods accordingly. PAVEMENTS 6.1. PAVEMENT SUBGRADE PREPARATION It is important that pavement subgrade support be relatively uniform, with no abrupt changes in the degree of support. Non-uniform pavement support can occur at the transition from cut to fill areas, as a result of varying soil moisture contents or soil types, or where improperly placed utility backfill has been placed across or through areas to be paved. Improper subgrade preparation such as inadequate vegetation removal, failure to identify soft or unstable areas by proofrolling, and inadequate or improper compaction can also produce non-uniform subgrade support. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 26 We recommend that pavements be supported by a minimum 24 inches of new structural fill or 24 inches of on-site native soils prepared as structural fill. To achieve this compacted structural fill thickness, the subgrade should be overexcavated to a depth of 12 inches below final grade, the resultant subgrade should then be scarified to a depth of 12 inches, moisture conditioned as necessary, and compacted to a minimum 95% of the materials Standard Proctor maximum dry density per Sections 4.1 and 4.2. Pavement subgrade moisture content at the time of compaction should be maintained between -1 and +3 percent of optimum for cohesive soils or between -2 and +2 percent of optimum for non-cohesive soils. The range of acceptable moisture contents for imported fill materials should be determined during laboratory Proctor testing of specific supplier delivered materials prior to earthwork. The final pavement subgrade should be tested for compaction and proofrolled immediately prior to pavement placement to detect localized areas of instability. Unsuitable or unstable areas should be reworked as necessary to provide a uniform, moisture conditioned, and compacted subgrade. If soft areas are identified during the subgrade preparation or if the subgrade soils have been exposed to adverse weather conditions, frost, excessive construction traffic, standing water, or similar conditions, the geotechnical engineer or his authorized field representative should be consulted to determine if corrective action is necessary. Proofrolling operations are not recommended in areas of new underground fuel tanks, fuel delivery lines, or underground utilities. It is recommended the prepared subgrades extend a minimum of 2 feet outside the pavements, where feasible. A representative of the geotechnical engineer should be present during final subgrade preparation to observe, document, and test compaction of the materials at the time of placement or rework. As recommended for all prepared soil subgrades, Olsson recommends that heavy, repetitive construction traffic be controlled, especially during periods of wet weather, to minimize disturbance. The final grades across this site should account for some post construction movement of exterior pavements due to moisture related shrink/swell or freeze/thaw cycles. To minimize this movement, it is recommended that the paved areas be designed with the maximum grades practical to further reduce the potential for ponding water. Our estimation of total movement is dependent on the grading plan incorporating positive drainage to reduce surface water infiltration of pavement subgrades. To increase pavement life and reduce the potential for heaving, a pavement maintenance program is recommended to regularly clean out and seal control joints and cracks that may develop. 6.2. PAVEMENT DESIGN – SITE PARKING AND DRIVE AREAS For Kum & Go stores, the daily traffic is relatively consistent and predictable, and primarily consists of passenger cars, beverage, food, and fuel delivery trucks, and trash trucks. Based on Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 27 the information provided by Kum & Go, the traffic volume for standard duty consists of 1,250 passenger cars and pickups per day, four (4) 3-axle, single-unit, delivery trucks per day, one (1) 3-axle, single-unit, trash truck every 2 days, and two (2) 5-axle, single trailer, fuel tanker per day. Based on this traffic volume, an 18-kip Equivalent Single Axle Load (ESAL18) value of approximately 122,500 is estimated for the pavement design life of 20 years for rigid pavements. The pavement section recommended here has been developed according to the AASHTO Guide for Design of Pavement Structures (1993) guidelines and is based on an estimated modulus of subgrade reaction (k) of 108 pci. R-value and Standard Proctor testing for this project are in progress and will be provided as an addendum once available. Based on our experience with this area and with similar soils we have assumed an R-value of 1.5 and a corresponding resilient modulus of 2.57. Other design parameters include reliability of 85 percent, combined standard error of 0.35 for concrete, initial design serviceability index of 4.2, and design terminal serviceability index of 2.25. In addition, we assumed drainage factor of 0.9 and load transfer factor of 3.6 assuming plain/unreinforced jointed concrete pavement. Olsson recommends that rigid concrete pavement be used in areas designated for heavily loaded trucks, lanes or concentrated lanes of repetitive traffic, or in non-designated areas that could experience turning truck traffic. For this project site, the following Portland cement pavement section is recommended. If the recommendations in this report are followed, a design life of 20 years should be anticipated. CONCRETE PAVEMENT Depth (in) Material Designation Material Specification 4.5 Concrete: CDOT Section 412 Portland Cement Concrete Pavement 4.0 Aggregate Base: CDOT Class 6 specification compacted to a minimum of 95% of maximum dry density as determined by Standard Proctor (ASTM D-698) 12.0 Minimum prepared subgrade thickness: In accordance with Sections 4.1 and 4.2 of this report. 12.0 Minimum compacted native soil thickness: Prepared in accordance with Sections 4.1 and 4.2 of this report. Curbs should be backfilled as soon as possible after pavement construction. Backfill should be properly compacted and sloped to prevent water from ponding and/or infiltrating pavement subgrades. Pavement joints should be caulked, and cracks should be quickly patched or sealed as they occur to prevent moisture from infiltrating and softening the subgrade soils. Kum & Go #0951 Report of Geotechnical Exploration East Prospect Road and South Lemay Ave Fort Collins, Colorado Olsson Project No. 020-28830 020-28830 28 LIMITATIONS The conclusions and recommendations presented in this report are based on the information available regarding the proposed construction, the results obtained from our soil test borings and sampling procedures, the results of the laboratory testing program, and our experience with similar projects. The soil test borings represent a very small statistical sampling of subsurface soils, and it is possible that conditions may be encountered during construction that are substantially different from those indicated by the soil test borings. In these instances, adjustments to design and construction may be necessary. This geotechnical report is based on the site plan and information provided to Olsson and our understanding of the project as noted in this report. Changes in the location or design of new structures and/or pavements could significantly affect the conclusions and recommendations presented in this geotechnical report. Olsson should be contacted in the event of such changes to determine if the recommendations of this report remain appropriate for the revised site design. This report was prepared under the direction and supervision of a Professional Engineer registered in the State of Colorado employed by Olsson. The conclusions and recommendations contained herein are based on generally accepted, professional geotechnical engineering practices at the time of this report, within this geographic area. No warranty, express or implied, is intended or made. This report has been prepared for the exclusive use of Kum & Go and their authorized representatives for specific application to the proposed project. Olsson appreciates the opportunity to provide our services on this project and look forward to working with you during construction. Should you have any questions, please do not hesitate to contact us. Respectfully submitted, Olsson, Inc. Allison Crawford, E.I. Edward Schnackenberg, P.E. Assistant Engineer Geotechnical Engineer F:\2020\2501-3000\020-2883\40-Design\Reports\FOPS\Report\21-06-24_FOPS_020-28830_Kum & Go #0951 Geotechnical Report.docx SITE LOCATION PLAN KUM & GO #951 FORT COLLINS, COLORADO OLSSON PROJECT NO. 020-28830 PROJECT SITE S LEMAY AVEE PROSPECT RD Boring Depth B-1 25 B-2 25 B-3 25 B-4 25 B-5 25 B-6 10 Scale: nts Project: 020-28830 Approved by: MRF Date: 5/13/2021 Boring Location Plan Kum & Go Store #951 949 East Prospect Road Fort Collins, Colorado Approximate Coordinates 40.566873° N 105.058457° W 40.566787° N 105.058155° W 40.566690° N 105.058160° W 40.566482° N 105.058588° W 40.566514° N 105.058294° W 40.566456° N 105.058118° W SYMBOLS AND NOMENCLATURE DRILLING NOTES DRILLING AND SAMPLING SYMBOLS SS: Split-Spoon Sample (1.375” ID, 2.0” OD) HSA: Hollow Stem Auger NE: Not Encountered U: Thin-Walled Tube Sample (3.0” OD) CFA: Continuous Flight Auger NP: Not Performed CS: Continuous Sample HA: Hand Auger NA: Not Applicable BS: Bulk Sample CPT: Cone Penetration Test % Rec: Percent of Recovery MC: Modified California Sampler WB: Wash Bore W D: While Drilling GB: Grab Sample RB: Rock Bit IAD: Immediately After Drilling SPT: Standard Penetration Test Blows per 6.0” PP: Pocket Penetrometer AD: After Drilling DRILLING PROCEDURES Soil samples designated as “U” samples on the boring logs were obtained in using Thin-Walled Tube Sampling techniques. Soil samples designated as “SS” samples were obtained during Penetration Test using a Split-Spoon Barrel sampler. The standard penetration resistance ‘N’ value is the number of blows of a 140-pound hammer falling 30 inches to drive the Split-Spoon sampler one foot. Soil samples designated as “MC” were obtained in using Thick-Walled, Ring-Lined, Split-Barrel Drive sampling techniques. Recovered samples were sealed in containers, labeled, and protected for transportation to the laboratory for testing. WATER LEVEL MEASUREMENTS Water levels indicated on the boring logs are levels measured in the borings at the times indicated. In relatively high permeable materials, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels is not possible with only short-term observations. SOIL PROPERTIES & DESCRIPTIONS Descriptions of the soils encountered in the soil test borings were prepared using Visual-Manual Procedures for Descriptions and Identification of Soils. PARTICLE SIZE Boulders 12 in. + Coarse Sand 4.75mm-2.0mm Silt 0.075mm-0.005mm Cobbles 12 in.-3 in. Medium Sand 2.0mm-0.425mm Clay <0.005mm Gravel 3 in.-4.75mm Fine Sand 0.425mm-0.075mm COHESIVE SOILS COHESIONLESS SOILS COMPONENT % Unconfined Compressive Consistency Strength (Qu) (tsf) Relative Density ‘N’ Value Description Percent (%) Very Soft <0.25 Very Loose 0 – 3 Trace <5 Soft 0.25 – 0.5 Loose 4 – 9 Few 5 - 10 Firm 0.5 – 1.0 Medium Dense 10 – 29 Little 15 - 25 Stiff 1.0 – 2.0 Dense 30 – 49 Some 30 - 45 Very Stiff 2.0 – 4.0 Very Dense ≥ 50 Mostly 50 - 100 Hard > 4.0 PLASTICITY CHART ROCK QUALITY DESIGNATION (RQD) Description RQD (%) Very Poor 0 – 25 Poor 25 – 50 Fair 50 – 75 Good 75 – 90 Excellent 90 – 100 G:\Admin\TEAMS\Geotech\AASHTO\Lab Forms\Symbols and Nomenclature gINT.doc GRAVEL AND GRAVELLY SOILS CLAYEY GRAVELS, GRAVEL - SAND - CLAY MIXTURES WELL-GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO FINES POORLY-GRADED SANDS, GRAVELLY SAND, LITTLE OR NO FINES SILTY SANDS, SAND - SILT MIXTURES CLAYEY SANDS, SAND - CLAY MIXTURES INORGANIC SILTS AND VERY FINE SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SAND OR SILTY SOILS INORGANIC CLAYS OF HIGH PLASTICITY SILTS AND CLAYS MORE THAN 50% OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE MORE THAN 50% OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZE MORE THAN 50% OF COARSE FRACTION PASSING ON NO. 4 SIEVE MORE THAN 50% OF COARSE FRACTION RETAINED ON NO. 4 SIEVE SOIL CLASSIFICATION CHART (APPRECIABLE AMOUNT OF FINES) (APPRECIABLE AMOUNT OF FINES) (LITTLE OR NO FINES) FINE GRAINED SOILS SAND AND SANDY SOILS SILTS AND CLAYS ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS LETTERGRAPH SYMBOLSMAJOR DIVISIONS COARSE GRAINED SOILS TYPICAL DESCRIPTIONS WELL-GRADED GRAVELS, GRAVEL - SAND MIXTURES, LITTLE OR NO FINES POORLY-GRADED GRAVELS, GRAVEL - SAND MIXTURES, LITTLE OR NO FINES SILTY GRAVELS, GRAVEL - SAND - SILT MIXTURES CLEAN GRAVELS GRAVELS WITH FINES CLEAN SANDS (LITTLE OR NO FINES) SANDS WITH FINES LIQUID LIMIT LESS THAN 50 LIQUID LIMIT GREATER THAN 50 HIGHLY ORGANIC SOILS NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT MC 1 SS 2 U 3 SS 4 SS 5 SS 6 MC 7 CONCRETE ALLUVIUM Clayey sand (SC), loose, moist, brown with white lensing Clayey sand (SC), very loose, moist, yellowish brown Clayey sand (SC), loose, moist, yellowish brown Poorly-graded sand with clay (SP-SC), medium dense, wet, yellowish brown, few gravel Poorly-graded sand with clay (SP-SC), medium dense, wet, yellowish brown, few gravel CLAYSTONE Weathered claystone, hard, wet, yellowish brown, trace sand Weathered claystone, hard, wet, bluish gray BASE OF BORING AT 24.1 FEET 0.5' 8.0' 14.5' 24.1' 21.7 23.4 12.7 42/26 P-200 = 47.3%2-3 0-1-1 N=2 13-12-7 N=19 7-12-25 N=37 50/3" 50/1"SAMPLE TYPENUMBERELEVATION(ft)4950 4945 4940 4935 4930 8.0 ft 7.1 ft Not Encountered VINE LABSGRAPHICLOGMATERIAL DESCRIPTION MOISTURE(%)LL/PI(%)CLASSIFICATION(USCS)Modified California Sampler Split Spoon Shelby Tube WD IAD AD Sheet 1 of 1 PROJECT NUMBER CME 55 LOCATION 6/8/21 M. ALMAND STARTED: DRILL CO.: DRILLER: METHOD: 6/8/21 CONTINUOUS FLIGHT AUGER ADDITIONAL DATA/ REMARKS Fort Collins, Colorado VINE LABS APPROX. SURFACE ELEV. (ft):4950 DEPTH(ft)0 5 10 15 20 020-28830 UNC. STR.(tsf)DRY DENSITY(pcf)FINISHED: DRILL RIG: LOGGED BY: Kum & Go #0951 PROJECT NAME CLIENT Kum & Go WATER LEVEL OBSERVATIONS OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 BOREHOLE REPORT NO. B-1 BLOWS/6"N-VALUE MC 1 SS 2 MC 3 SS 4 MC 5 SS 6 FILL Driller's Note: Boring was potholed by another contractor prior to Olsson's exploration. Pea gravel was placed as backfill after potholing was completed. ALLUVIUM Lean clay (CL), firm, moist, grayish brown Lean clay (CL), soft, moist, grayish brown Driller's Note: Fuel odor encountered from 5-10' Lean clay (CL), firm, moist, grayish brown, few sand Poorly-graded sand with clay (SP-SC), medium dense, wet, brown, few gravel CLAYSTONE Weathered claystone, hard, wet, grayish brown Weathered claystone, hard, wet, grayish brown BASE OF BORING AT 24.3 FEET 5.0' 9.7' 18.0' 24.3' 19.1 19.6 11.6 15.3 20.0 1.0 105.1 98.9 3-4 1-1-2 N=3 3-7 10-7-4 N=11 28-50/3" 50/4"SAMPLE TYPENUMBERELEVATION(ft)4950 4945 4940 4935 4930 14.0 ft 13.7 ft Not Encountered VINE LABSGRAPHICLOGMATERIAL DESCRIPTION MOISTURE(%)LL/PI(%)CLASSIFICATION(USCS)Modified California Sampler Split Spoon WD IAD AD Sheet 1 of 1 PROJECT NUMBER CME 55 LOCATION 6/8/21 M. ALMAND STARTED: DRILL CO.: DRILLER: METHOD: 6/8/21 CONTINUOUS FLIGHT AUGER ADDITIONAL DATA/ REMARKS Fort Collins, Colorado VINE LABS APPROX. SURFACE ELEV. (ft):4950 DEPTH(ft)0 5 10 15 20 020-28830 UNC. STR.(tsf)DRY DENSITY(pcf)FINISHED: DRILL RIG: LOGGED BY: Kum & Go #0951 PROJECT NAME CLIENT Kum & Go WATER LEVEL OBSERVATIONS OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 BOREHOLE REPORT NO. B-2 BLOWS/6"N-VALUE MC 1 SS 2 MC 3 SS 4 SS 5 MC 6 MC 7 ASPHALT FILL Lean clay (CL), firm, moist, dark brown, some gravel ALLUVIUM Lean clay (CL), soft, very moist, brown Lean clay (CL), firm, moist, brown Poorly-graded sand with clay (SP-SC), medium dense, wet, brown, some gravel CLAYSTONE Weathered claystone, hard, wet, brown, few sand Weathered claystone, hard, wet, grayish brown Weathered claystone, hard, wet, bluish gray BASE OF BORING AT 24.3 FEET 0.9' 3.5' 9.5' 14.5' 24.3' 26.3 24.7 23.4 13.6 38/23 P-200 = 38.0% 98.1 2-3 1-1-1 N=2 2-3 7-10- 16/5.9" 8-7-6 N=13 50/5.5" 50/3"SAMPLE TYPENUMBERELEVATION(ft)4950 4945 4940 4935 4930 9.5 ft 10.5 ft Not Encountered VINE LABSGRAPHICLOGMATERIAL DESCRIPTION MOISTURE(%)LL/PI(%)CLASSIFICATION(USCS)Modified California Sampler Split Spoon WD IAD AD Sheet 1 of 1 PROJECT NUMBER CME 55 LOCATION 6/8/21 M. ALMAND STARTED: DRILL CO.: DRILLER: METHOD: 6/8/21 CONTINUOUS FLIGHT AUGER ADDITIONAL DATA/ REMARKS Fort Collins, Colorado VINE LABS APPROX. SURFACE ELEV. (ft):4950 DEPTH(ft)0 5 10 15 20 020-28830 UNC. STR.(tsf)DRY DENSITY(pcf)FINISHED: DRILL RIG: LOGGED BY: Kum & Go #0951 PROJECT NAME CLIENT Kum & Go WATER LEVEL OBSERVATIONS OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 BOREHOLE REPORT NO. B-3 BLOWS/6"N-VALUE SS 1 MC 2 U 3 SS 4 MC 5 SS 6 MC 7 DEVELOPED ZONE ALLUVIUM Lean clay (CL), firm, moist, brown, little sand, trace gravel Lean clay (CL), stiff, moist, brown, little sand and gravel Lean clay (CL), stiff, moist, brown, little sand and gravel Poorly-graded sand with clay (SP-SC), very dense, wet, brown, little gravel Poorly-graded sand with clay (SP-SC), very dense, wet, brown, little gravel CLAYSTONE Weathered claystone, hard, wet, grayish brown, trace sand Weathered claystone, hard, wet, bluish gray BASE OF BORING AT 24.3 FEET 0.3' 8.0' 14.5' 24.2' 21.1 10.1 11.9 12.5 20.0 4.1 104.4 111.4 4-2-3 N=5 5-6 9-13-50 N=63 50/5.5" 50/5.5" 50/2"SAMPLE TYPENUMBERELEVATION(ft)4950 4945 4940 4935 4930 7.8 ft 7.6 ft Not Encountered VINE LABSGRAPHICLOGMATERIAL DESCRIPTION MOISTURE(%)LL/PI(%)CLASSIFICATION(USCS)Split Spoon Modified California Sampler Shelby Tube WD IAD AD Sheet 1 of 1 PROJECT NUMBER CME 55 LOCATION 6/8/21 M. ALMAND STARTED: DRILL CO.: DRILLER: METHOD: 6/8/21 CONTINUOUS FLIGHT AUGER ADDITIONAL DATA/ REMARKS Fort Collins, Colorado VINE LABS APPROX. SURFACE ELEV. (ft):4950 DEPTH(ft)0 5 10 15 20 020-28830 UNC. STR.(tsf)DRY DENSITY(pcf)FINISHED: DRILL RIG: LOGGED BY: Kum & Go #0951 PROJECT NAME CLIENT Kum & Go WATER LEVEL OBSERVATIONS OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 BOREHOLE REPORT NO. B-4 BLOWS/6"N-VALUE MC 1 SS 2 MC 3 SS 4 SS 5 MC 6 SS 7 DEVELOPED ZONE ALLUVIUM Clayey sand (SC), medium dense, slightly moist, brown Clayey sand (SC), medium dense, slightly moist, brown Clayey sand (SC), medium dense, slightly moist, brown, trace gravel Poorly-graded sand with clay (SP-SC), medium dense, wet, brown, little gravel Poorly-graded sand with clay (SP-SC), medium dense, wet, brown, little gravel CLAYSTONE Weathered claystone, very stiff, wet, yellowish brown, trace sand Weathered claystone, hard, wet, yellowish brown, trace sand Weathered claystone, hard, wet, bluish gray BASE OF BORING AT 24.3 FEET 0.3' 7.5' 14.5' 24.2' 14.7 12.6 23.6 44/29110.87-10 4-3-2 N=5 4-3 6-7-7 N=14 6-13-15 N=28 50/5.5" 50/2"SAMPLE TYPENUMBERELEVATION(ft)4950 4945 4940 4935 4930 8.0 ft 7.8 ft Not Encountered VINE LABSGRAPHICLOGMATERIAL DESCRIPTION MOISTURE(%)LL/PI(%)CLASSIFICATION(USCS)Modified California Sampler Split Spoon WD IAD AD Sheet 1 of 1 PROJECT NUMBER CME 55 LOCATION 6/8/21 M. ALMAND STARTED: DRILL CO.: DRILLER: METHOD: 6/8/21 CONTINUOUS FLIGHT AUGER ADDITIONAL DATA/ REMARKS Fort Collins, Colorado VINE LABS APPROX. SURFACE ELEV. (ft):4950 DEPTH(ft)0 5 10 15 20 020-28830 UNC. STR.(tsf)DRY DENSITY(pcf)FINISHED: DRILL RIG: LOGGED BY: Kum & Go #0951 PROJECT NAME CLIENT Kum & Go WATER LEVEL OBSERVATIONS OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 BOREHOLE REPORT NO. B-5 BLOWS/6"N-VALUE SS 1 MC 2 MC 3 SS 4 DEVELOPED ZONE ALLUVIUM Lean clay (CL), stiff, moist, brown, some sand Lean clay (CL), stiff, moist, brown, some sand Lean clay (CL), stiff, moist, brown, some sand Poorly-graded sand with clay (SP-SC), medium dense, wet, brown, little gravel BASE OF BORING AT 10.5 FEET 0.3' 7.0' 10.5' 16.1 18.6 11.7 P-200 = 51.6% 86.9 5-6-6 N=12 7-9 2-4 25-12-14 N=26SAMPLE TYPENUMBERELEVATION(ft)4950 4945 4940 7.5 ft 7.1 ft Not Encountered VINE LABSGRAPHICLOGMATERIAL DESCRIPTION MOISTURE(%)LL/PI(%)CLASSIFICATION(USCS)Split Spoon Modified California Sampler WD IAD AD Sheet 1 of 1 PROJECT NUMBER CME 55 LOCATION 6/8/21 M. ALMAND STARTED: DRILL CO.: DRILLER: METHOD: 6/8/21 CONTINUOUS FLIGHT AUGER ADDITIONAL DATA/ REMARKS Fort Collins, Colorado VINE LABS APPROX. SURFACE ELEV. (ft):4950 DEPTH(ft)0 5 10 020-28830 UNC. STR.(tsf)DRY DENSITY(pcf)FINISHED: DRILL RIG: LOGGED BY: Kum & Go #0951 PROJECT NAME CLIENT Kum & Go WATER LEVEL OBSERVATIONS OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 BOREHOLE REPORT NO. B-6 BLOWS/6"N-VALUE B-1 MC-1 1.0 - 2.0' 21.7 42 16 26 47.3 B-1 SS-2 3.5 - 5.0' 23.4 B-1 MC-7 24.0 - 24.1' 12.7 B-2 SS-2 6.0 - 7.5' 19.1 B-2 MC-3 9.0 - 10.0' 19.6 105.1 0.604 87.3 1.0 14.5 B-2 SS-4 14.0 - 15.5' 11.6 B-2 MC-5 19.0 - 19.8' 15.3 98.9 0.705 58.6 B-2 SS-6 24.0 - 24.3' 20.0 B-3 SS-2 3.5 - 5.0' 26.3 B-3 MC-3 6.0 - 7.0' 24.7 98.1 0.719 92.9 B-3 - - ' 23.4 38.0 B-3 MC-6 19.0 - 19.5' 13.6 38 15 23 B-4 MC-2 3.5 - 4.5' 21.1 104.4 0.615 92.6 B-4 SS-4 9.0 - 10.5' 10.1 B-4 MC-5 14.0 - 14.5' 11.9 B-4 SS-6 19.0 - 19.5' 12.5 111.4 0.513 65.7 4.1 6.9 B-4 MC-7 24.0 - 24.2' 20.0 B-5 MC-1 1.0 - 2.0' 14.7 110.8 0.521 76.1 44 15 29 B-5 SS-4 9.0 - 10.5' 12.6 B-5 MC-6 19.0 - 19.5' 23.6 B-6 SS-1 1.0 - 2.5' 16.1 51.6 B-6 MC-2 3.5 - 4.5' 18.6 86.9 0.941 53.4 B-6 SS-4 9.0 - 10.5' 11.7 STRAIN (%) ATTERBERG LIMITS PLASTIC LIMIT SATURATION (%) VOID RATIOBORING NUMBER DRY DENSITY (pcf) SAMPLE DEPTH (ft)PLASTIC INDEX LIQUID LIMIT MOISTURE CONTENT (%) SAMPLE I.D. SUMMARY OF LABORATORY RESULTS PAGE 1 OF 1 USCS CLASS.P-200 UNCONFINED STRENGTH (tsf) OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 PROJECT NAME:Kum & Go #0951 PROJECT NUMBER:020-28830 CLIENT:Kum & Go PROJECT LOCATION:Fort Collins, Colorado 3990 Fox Street TEL 303.237.2072 Denver, CO 80216 FAX 303.237.2659 Dilution 100:1 Test Results Nathan Rasmussen Brown clay, trace sand www.olsson.com Soil Corrosion Suite Project Information Sample and Test Information Kum & Go 951 020-28830Project Number: Client Name: Project Location: Project Name: Date Tested: Sample Description: 6/16/2021 462 too wet 462 Kum & Go pH Meter Reading Readings (ohm*cm) Fort Collins, Colorado Dilution 3 Concentration, ppm Sample portion passing the #10 sieve used in testing. Each reading performed after additional water was added. 617 511 488 477 Lowest Resistivity (ohm*cm) 8.6 pH (ASTM G51) Electrical Resistivity (ASTM G57, -#10) 204 Concentration, % mass 0.0204 Reading Concentration, mg/L Sample Location:B1 Bulk 3-6 feet Water Soluble Sulfate (Colorado Procedure CP-L-2103) Water Soluble Chloride (Colorado Procedure CP-L-2104) Concentration, % mass 0.11110011 Laboratory Technician: -3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0 0.5 1.0 1.5 2.0 2.5100 1,000 10,000 Sample Description:Notes:Swell potential (1000 psf surcharge): 0.49%Brown Sandy Clay SWELL / CONSOLIDATION TEST STRAIN, %Notes:Brown Sandy Clay Swell potential (1000 psf surcharge): 0.49% Distilled Water17.2MC-5 B-2 Initial Water Content (%): Final Water Content (%): Initial Dry Density (pcf): Initial Void Ratio: Final Void Ratio: Initial Degree of Saturation (%): Final Degree of Saturation (%):100.0 C NA Ring Sampler 15.3 98.9 85.9 2.7 N. RASMUSSEN 19.0 - 19.8' 6/11/2021 0.450 0.480 Boring No: Sample ID: Sample Depth: Start Date: Technician: Apparatus: Specific Gravity:ATTERBERG LIMITS LL PL PI Classification Est. Preconsolidation Stress (tsf): Laboratory Water Type: Test Procedure Method: Interpretation Procedure: Stress at Inundation (tsf): Specimen Trimming Method: STRESS, tsf 1000.00 PROJECT NAME:Kum & Go #0951 PROJECT NUMBER:020-28830 CLIENT:Kum & Go PROJECT LOCATION:Fort Collins, Colorado OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 Swelling Pressure = 3100 psf -3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0 0.5 1.0 1.5 2.0 2.5100 1,000 10,000 Sample Description:Notes:Swell potential (200 psf surcharge): 3.37%Brown Sandy Clay SWELL / CONSOLIDATION TEST STRAIN, %Notes:Brown Sandy Clay Swell potential (200 psf surcharge): 3.37% 29 Distilled Water20.0MC-1 B-5 Initial Water Content (%): Final Water Content (%): Initial Dry Density (pcf): Initial Void Ratio: Final Void Ratio: Initial Degree of Saturation (%): Final Degree of Saturation (%):100.0 C NA Ring Sampler 14.7 110.8 76.3 2.7 DNV Swell E N. RASMUSSEN 1.0 - 2.0' 6/11/2021 0.511 0.521 Boring No: Sample ID: Sample Depth: Start Date: Technician: Apparatus: Specific Gravity:ATTERBERG LIMITS LL PL PI Classification 44 15 Est. Preconsolidation Stress (tsf): Laboratory Water Type: Test Procedure Method: Interpretation Procedure: Stress at Inundation (tsf): Specimen Trimming Method: STRESS, tsf 200.00 PROJECT NAME:Kum & Go #0951 PROJECT NUMBER:020-28830 CLIENT:Kum & Go PROJECT LOCATION:Fort Collins, Colorado OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 Swelling Pressure = 4800 psf -3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0 0.5 1.0 1.5 2.0 2.5100 1,000 10,000 Sample Description:Notes:Swell potential (500 psf surcharge): 1.01%Brown Sandy Clay SWELL / CONSOLIDATION TEST STRAIN, %Notes:Brown Sandy Clay Swell potential (500 psf surcharge): 1.01% Distilled Water14.4MC-2 B-6 Initial Water Content (%): Final Water Content (%): Initial Dry Density (pcf): Initial Void Ratio: Final Void Ratio: Initial Degree of Saturation (%): Final Degree of Saturation (%):78.5 C NA Ring Sampler 18.6 86.9 78.8 2.7 N. RASMUSSEN 3.5 - 4.5' 6/11/2021 0.497 0.638 Boring No: Sample ID: Sample Depth: Start Date: Technician: Apparatus: Specific Gravity:ATTERBERG LIMITS LL PL PI Classification Est. Preconsolidation Stress (tsf): Laboratory Water Type: Test Procedure Method: Interpretation Procedure: Stress at Inundation (tsf): Specimen Trimming Method: STRESS, tsf 500.00 PROJECT NAME:Kum & Go #0951 PROJECT NUMBER:020-28830 CLIENT:Kum & Go PROJECT LOCATION:Fort Collins, Colorado OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 Swelling Pressure = 2000 psf 1,000 STRESS, psf Boring Depth B-1 25 B-2 25 B-3 25 B-4 25 B-5 25 B-6 10 Scale: nts Project: 020-28830 Approved by: MRF Date: 5/13/2021 Boring Location Plan Kum & Go Store #951 949 East Prospect Road Fort Collins, Colorado Approximate Coordinates 40.566873° N 105.058457° W 40.566787° N 105.058155° W 40.566690° N 105.058160° W 40.566482° N 105.058588° W 40.566514° N 105.058294° W 40.566456° N 105.058118° W Cross Section Location Map AJC 6/22/2021 4,924 4,926 4,928 4,930 4,932 4,934 4,936 4,938 4,940 4,942 4,944 4,946 4,948 4,950 4,952 0 5 10 15 20 25 30 35 40 45 4,924 4,926 4,928 4,930 4,932 4,934 4,936 4,938 4,940 4,942 4,944 4,946 4,948 4,950 4,952 0 5 10 15 20 25 30 35 40 45 Elevation (ft)Distance Along Baseline (ft) USCS Well-graded Gravel USCS Low Plasticity Clay USCS Poorly-graded Sand with Clay Shale Asphalt USCS Poorly-graded Gravel NOTE: Soil stratification, as shown on the geologic profile, represents soil conditions at the boring locations: however, variations may occur between or around the boring locations. NOTE: Soil stratification, as shown on the geologic profile, represents soil conditions at the boring locations: however, variations may occur between or around the boring locations. GROUNDWATER DEPTH IMMEDIATELY AFTER DRILLING GROUNDWATER DEPTH AFTER DRILLING GROUNDWATER DEPTH WHILE DRILLING OLSSON, INC. 5180 SMITH ROAD, UNIT F DENVER, COLORADO 80216 PROJECT NAME:Kum & Go #0951 PROJECT NUMBER:020-28830 CLIENT:Kum & Go PROJECT LOCATION:Fort Collins, Colorado GEOLOGIC PROFILE B-2B-3B-6 Fill - Lean Clay Fill - Pea Gravel Alluvium - Lean Clay Alluvium - Poorly-graded sand with clay Weathered Claystone Approximate Project Location HISTORICAL IMAGES F