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HomeMy WebLinkAboutPRECISION TECHNOLOGY - PDP200013 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTREPORT COVER PAGE Geotechnical Engineering Report __________________________________________________________________________ Precision Technology Warehouse Fort Collins, Colorado June 5, 2020 Terracon Project No. 20205049 Prepared for: Eldon James Corporation Denver, Colorado Prepared by: Terracon Consultants, Inc. Fort Collins, Colorado Responsive ■ Resourceful ■ Reliable 1 REPORT TOPICS INTRODUCTION ............................................................................................................. 1 SITE CONDITIONS ......................................................................................................... 1 PROJECT DESCRIPTION .............................................................................................. 2 GEOTECHNICAL CHARACTERIZATION ...................................................................... 3 GEOTECHNICAL OVERVIEW ....................................................................................... 5 EARTHWORK................................................................................................................. 7 GROUND IMPROVEMENT ........................................................................................... 12 SHALLOW FOUNDATIONS ......................................................................................... 13 SEISMIC CONSIDERATIONS ...................................................................................... 15 FLOOR SLABS............................................................................................................. 16 BELOW-GRADE STRUCTURES ................................................................................. 17 PAVEMENTS ................................................................................................................ 18 CORROSIVITY.............................................................................................................. 22 GENERAL COMMENTS ............................................................................................... 22 Note: This report was originally delivered in a web-based format. Orange Bold text in the report indicates a referenced section heading. The PDF version also includes hyperlinks which direct the reader to that section and clicking on the GeoReport logo will bring you back to this page. For more interactive features, please view your project online at client.terracon.com. ATTACHMENTS EXPLORATION AND TESTING PROCEDURES SITE LOCATION AND EXPLORATION PLANS EXPLORATION RESULTS SUPPORTING INFORMATION Note: Refer to each individual Attachment for a listing of contents. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable i REPORT SUMMARY Topic 1 Overview Statement 2 Project Overview A geotechnical exploration has been performed for the proposed Precision Technology Warehouse to be constructed at 3486 Precision Drive in Fort Collins, Colorado. Twelve (12) borings were performed to depths of approximately 10 to 30 feet below existing site grades. Subsurface Conditions Subsurface conditions encountered in our exploratory borings generally consisted of about 8 to 17 feet of interlayered lean clay with sand to clayey sand and silty sand over about to 5 to 10 feet of interlayered lean clay with sand and well graded sand with silt and gravel. Isolated areas of lean clay with sand and well graded sand with silt were encountered around the site. Claystone bedrock was encountered below the overburden soils in most of the borings at depths of approximately 14 to 29 feet below existing site grades. The upper approximately 3 to 10 feet of bedrock was highly weathered and comparatively soft in some of the borings. Boring logs are presented in the Exploration Results section of this report. Groundwater Conditions Groundwater was encountered in most of our test borings at depths of about 14 to 18 feet below existing site grades at the time of drilling. Groundwater levels can fluctuate in response to site development and to varying seasonal and weather conditions, irrigation on or adjacent to the site and fluctuations in nearby water features. Geotechnical Concerns ■ Comparatively Soft lean clay and loose sand soils were encountered within the upper approximately 15 to 20 feet of the borings completed at this site. Soft and loose soils were particularly present as depths approached existing groundwater. These materials present a risk for potential settlement of shallow foundations, floor slabs, pavements and other surficial improvements. These materials can also be susceptible to disturbance and loss of strength under repeated construction traffic loads and unstable conditions could develop. Stabilization of soft soils may be required at some locations to provide adequate support for construction equipment and proposed structures. Terracon should be contacted if these conditions are encountered to observe the conditions exposed and to provide guidance regarding stabilization (if needed). ■ As previously stated, groundwater was measured at depths ranging from about 14 to 18 feet below existing site grades. We understand a below grade area may be planned in the loading dock planned at this site. Terracon recommends maintaining a separation of at least 3 feet between the bottom of proposed below-grade foundations and measured groundwater levels. It is also possible and likely that groundwater levels below this site may rise as water levels in the nearby water features rise. Final site grading should be planned and designed to avoid cuts where shallow groundwater is known to exist, and also in areas where such grading would create shallow groundwater conditions. If deeper cuts are unavoidable, installation of a subsurface drainage system may be needed. ■ Expansive soils and bedrock are present on this site and these conditions constitute a geologic hazard. This report provides recommendations to help mitigate the effects of soil shrinkage and expansion. However, even if these procedures are followed, some movement and cracking in the structures, pavements, and flatwork is possible. The severity of cracking and other damage such as uneven floor slabs Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable ii Topic 1 Overview Statement 2 construction. It is imperative the recommendations described in section Grading and Drainage section of the Earthwork section of this report be followed to reduce potential movement. Earthwork On-site soils typically appear suitable for use as general engineered fill and backfill on the site provided they are placed and compacted as described in this report. Import materials (if needed) should be evaluated and approved by Terracon prior to delivery to the site. Earthwork recommendations are presented in the Earthwork section of this report. Ground Improvements Due to comparatively soft clay and loose sand soils encountered to depths up to about 30 feet below existing site grades, we anticipate ground improvement will likely be necessary below shallow foundations. Ground improvements could include over- excavation and replacement with properly prepared and compacted fill or rammed aggregate piers below the proposed foundations. Recommendations for ground improvements below proposed foundations are provided in the Ground Improvements section of this report. Grading and Drainage The amount of movement of foundations, floor slabs, pavements, etc. will be related to the wetting of underlying supporting soils. Therefore, it is imperative the recommendations discussed in the Grading and Drainage section of the Earthwork section this report be followed to reduce potential movement. As discussed in the Grading and Drainage section of this report, surface drainage should be designed, constructed and maintained to provide rapid removal of surface water runoff away from the existing and proposed buildings and pavements. Water should not be allowed to pond adjacent to foundations or on pavements and conservative irrigation practices should be followed to avoid wetting foundation/slab soils and pavement subgrade. Excessive wetting of foundations/slab soils and subgrade can cause movement and distress to foundations, floor slabs, concrete flatwork and pavements. Foundations The proposed building can be supported by a shallow, spread footing foundation system. Design recommendations for foundations for the proposed structure and related structural elements are presented in the Shallow Foundations section of this report. Floor Systems A slab-on-grade may be utilized for the interior floor system for the proposed building provided the native clay soils are over-excavated to a depth of at least 4 feet, moisture conditioned, and compacted on-site soils. Design recommendations for floor slabs for the proposed structure and related structural elements are presented in the Floor Slab section of this report. Pavements Recommended Pavement thicknesses for this project include 4 inches of asphalt over 6 inches of aggregate base course in light-duty parking areas, 8 inches of asphalt over 6 inches of aggregate base course in drive lanes and 7 inches of asphalt of 10 inches of aggregate base course in heavy-duty loading areas. Additional pavement section alternatives and discussion are presented in the report. Seismic Considerations As presented in the Seismic Considerations section of this report, the International Building Code, which refers to Section 20 of ASCE 7, indicates the seismic site Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable iii Topic 1 Overview Statement 2 1. If the reader is reviewing this report as a pdf, the topics (bold orange font) above can be used to access the appropriate section of the report by simply clicking on the topic itself. 2. This summary is for convenience only. It should be used in conjunction with the entire report for design making and design purposes. It should be recognized that specific details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. Responsive ■ Resourceful ■ Reliable 1 INTRODUC TION Geotechnical Engineering Report Precision Technology Warehouse 3486 Precision Drive Fort Collins, Colorado Terracon Project No. 20205049 June 5, 2020 INTRODUCTION This report presents the results of our subsurface exploration and geotechnical engineering services performed for the proposed Technology Warehouse to be located at 3486 Precision Drive in Fort Collins, Colorado. The purpose of these services is to provide information and geotechnical engineering recommendations relative to: ■ Subsurface soil conditions ■ Foundation design and construction ■ Groundwater conditions ■ Floor system design and construction ■ Site preparation and earthwork ■ Seismic considerations ■ Excavation considerations ■ Lateral earth pressures ■ Pavement design and construction The geotechnical engineering scope of services for this project included the advancement of twelve (12) test borings to depths ranging from approximately 10 to 30 feet below existing site grades. Maps showing the site and boring locations are shown in the Site Location and Exploration Plan sections, respectively. The results of the laboratory testing performed on soil and bedrock samples obtained from the site during the field exploration are included on the boring logs and as separate graphs in the Exploration Results section of this report. SITE CONDITIONS The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps. Item Description Parcel Information The project site is located at 3486 Precision Drive in Fort Collins, Colorado. The approximate Latitude/Longitude of the center of the site is 40.5184° N/105.0135°W (Please refer to Site Location). Existing Improvements The site is currently occupied by vacant land, a soil stockpile is present on the south side of the site. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 2 Item Description Surrounding Developments In general, the site is surrounded by commercial/industrial developments followed by a multi-family apartment complex to the east, the existing Fossil Ridge high school to the south and vacant land to the west and north. Current Ground Cover The current ground cover is native grasses and weeds. Existing Topography The site is relatively flat with a soil stockpile on the south side of the site. PROJECT DESCRIPTION Our final understanding of the project conditions is as follows: Item Description Information Provided The following project information was provided to us through conversation with the client and a provided Floor Plan for the project prepared by The Architects’ Studio and dated 2/11/2020. Project Description The project includes the construction of a new warehouse building, associated drive and parking areas and landscaped area. A loading dock is planned in the northeast portion of the proposed building. Proposed Construction The proposed construction consists of a single-story building. The building will likely be slab-on-grade with no basement. We understand the warehouse portion of the building will likely be constructed using tilt-up concrete techniques and the office portion of the building will be constructed stick-frame techniques. We understand the building height will range between about 16 feet to 24 feet tall. Maximum Loads (assumed) ■ Columns: 50 to 250 kips ■ Walls: 1 to 5 kips per linear foot (klf) ■ Slabs: 150 pounds per square foot (psf) Grading/Slopes We anticipate minor cuts and fills on the order of 5 feet or less will be required to achieve proposed grades. Below-grade Structures We anticipate some areas of the loading dock may be constructed below- grade. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 3 Item Description Pavements We assume both rigid (concrete) and flexible (asphalt) pavement sections should be considered. We assume design of the new privately-maintained pavements for the project will be based on the procedures described by the National Asphalt Pavement Associations (NAPA) and the American Concrete Institute (ACI). Anticipated traffic is as follows: ■ Automobile Parking Areas • NAPA Class I - Parking stalls and parking lots for cars and pick-up trucks, with Equivalent Single Axle Load (ESAL) up to 7,000 over 20 years • ACI Category A: Automobile parking with an ADTT of 1 over 20 years ■ Main Traffic Corridors • NAPA Class II – Parking lots with a maximum of 10 trucks per day with Equivalent Single Axle Load (ESAL) up to 27,000 over 20 years (Including trash trucks) • ACI Category A: Automobile parking area and service lanes with an ADTT of up to 10 over 20 years ■ Heavy Load Areas • NAPA Class III – Delivery lanes with up to 10 trucks per day with Equivalent Single Axle Load (ESAL) up to 110,000 over 20 years • ACI Category C: Truck areas with an ADTT of up to 100 over 20 years If project information or assumptions vary from what is described above or if location of construction changes, we should be contacted as soon as possible to confirm and/or modify our recommendations accordingly. GEOTECHNICAL CHARACTERIZATION Subsurface Profile We have developed a general characterization of the subsurface conditions based upon our review of the subsurface exploration, laboratory data, geologic setting and our understanding of the project. This characterization, termed GeoModel, forms the basis of our geotechnical calculations and evaluation of site preparation and foundation options. Conditions encountered at each exploration point are indicated on the individual logs. The individual logs and the GeoModel can be found in the Exploration Results section of this report. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 4 Model Layer Layer Name General Description Approximate Depth to Bottom of Stratum 1 Interlayered silt and clay Sandy lean clay to clayey sand interlayered with silty sand. Lean clay ranges from soft to stiff, silty sand is typically loose to medium dense. About 8 to 17 feet below existing site grades. 2 Well graded sand Well graded sand with silt and gravel, medium dense. About 15 feet below existing site grades. 3 Lean clay Lean clay with sand, medium stiff to stiff. About 14 to 26 feet below existing site grades. 4 Interlayered lean clay and sand Interlayered lean clay with sand to clayey sand and well graded sand with silt and gravel. Lean clay ranges from medium stiff to stiff, sand ranges from loose to medium dense. About 24 to 27 feet below existing site grades or to the maximum depths of exploration of about 30 feet below existing site grades. 5 Bedrock Claystone bedrock, firm to very, some highly weathered bedrock in the upper 5 feet. To the maximum depths of exploration of about 30 feet below existing site grades. As noted in General Comments, this characterization is based upon widely spaced exploration points across the site and variations are likely. Groundwater Conditions The boreholes were observed while drilling for the presence and level of groundwater. The water levels observed in the boreholes are noted on the attached boring logs, and are summarized below: Boring Number Depth to Groundwater While Drilling, ft. B-1 14 B-2 14 B-3 17 B-4 17 B-5 17 Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 5 factors. Groundwater level fluctuations occur due to seasonal variations in the water levels present in nearby water features, amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the structure(s) may be higher or lower than the levels indicated on the boring logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project. Fluctuations in groundwater levels can best be determined by implementation of a groundwater monitoring plan. Such a plan would include installation of groundwater piezometers, and periodic measurement of groundwater levels over a sufficient period of time. Laboratory Testing Representative soil samples were selected for swell-consolidation testing and exhibited 0.1 percent compression to 0.8 percent swell when wetted. Samples of clay soils and claystone bedrock exhibited unconfined compressive strengths of approximately 1,093 and 3,934 pounds per square foot (psf). Samples of site soils and bedrock selected for plasticity testing exhibited low to moderate plasticity with liquid limits ranging from non-plastic to 38 and plasticity indices ranging from non-plastic to 28. Laboratory test results are presented in the Exploration Results section of this report. GEOTECHNICAL OVERVIEW Based on subsurface conditions encountered in the borings, the site appears suitable for the proposed construction from a geotechnical point of view provided certain precautions and design and construction recommendations described in this report are followed and the owner understands the inherent risks associated with construction on sites underlain by expansive soils and bedrock. We have identified several geotechnical conditions that could impact design, construction and performance of the proposed structures, pavements, and other site improvements. These included soft, low strength soils, shallow groundwater and expansive soils and bedrock. These conditions will require particular attention in project planning, design and during construction and are discussed in greater detail in the following sections. Low Strength Soils Comparatively Soft lean clay and loose sand soils were encountered within the upper approximately 15 to 20 feet of the borings completed at this site. Soft and loose soils were particularly present as depths approached existing groundwater. These materials present a risk for potential settlement of shallow foundations, floor slabs, pavements and other surficial Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 6 improvements. These materials can also be susceptible to disturbance and loss of strength under repeated construction traffic loads and unstable conditions could develop. Stabilization of soft soils may be required at some locations to provide adequate support for construction equipment and proposed structures. Terracon should be contacted if these conditions are encountered to observe the conditions exposed and to provide guidance regarding stabilization (if needed). Shallow Groundwater As previously stated, groundwater was measured at depths ranging from about 14 to 18 feet below existing site grades. We understand a below grade area may be planned in the loading dock planned at this site. Terracon recommends maintaining a separation of at least 3 feet between the bottom of proposed below-grade foundations and measured groundwater levels. It is also possible and likely that groundwater levels below this site may rise as water levels in the nearby water features rise. Final site grading should be planned and designed to avoid cuts where shallow groundwater is known to exist, and also in areas where such grading would create shallow groundwater conditions. If deeper cuts are unavoidable, installation of a subsurface drainage system may be needed. Expansive Soils and Bedrock Expansive soils and bedrock are present on this site and these conditions constitute a geologic hazard. This report provides recommendations to help mitigate the effects of soil shrinkage and expansion. However, even if these procedures are followed, some movement and cracking in the structures, pavements, and flatwork is possible. The severity of cracking and other damage such as uneven floor slabs and flat work will probably increase if modification of the site results in excessive wetting or drying of the expansive clays. Eliminating the risk of movement and cosmetic distress is generally not feasible, but it may be possible to further reduce the risk of movement if significantly more expensive measures are used during construction. It is imperative the recommendations described in section Grading and Drainage section of the Earthwork section of this report be followed to reduce potential movement. Foundation and Floor System Recommendations The proposed building can be supported by a shallow, spread footing foundation system. Due to soft clay and loose sand soils encountered to depths up to about 30 feet below existing site grades, we anticipate ground improvement will likely be necessary below shallow foundations. Ground improvements could include over-excavation and replacement with properly prepared and compacted fill or rammed aggregate piers below the proposed foundations. Recommendations for ground improvements below proposed foundations are provided in the Ground Improvements section of this report. Design recommendations for foundations for the proposed structure and related structural elements are presented in the Shallow Foundations section of this report. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 7 A slab-on-grade may be utilized for the interior floor system for the proposed building provided the native clay soils are over-excavated to a depth of at least 4 feet, moisture conditioned, and compacted on-site soils. Design recommendations for floor slabs for the proposed structure and related structural elements are presented in the Floor Slab section of this report. The General Comments section provides an understanding of the report limitations. EARTHWORK The following presents recommendations for site preparation, excavation, subgrade preparation, fill materials, compaction requirements, utility trench backfill, grading and drainage and exterior slab design and construction. Earthwork on the project should be observed and evaluated by Terracon. Evaluation of earthwork should include observation and/or testing of over-excavation, removal of existing fill, subgrade preparation, placement of engineered fills, subgrade stabilization and other geotechnical conditions exposed during the construction of the project. Site Preparation Prior to placing any fill, strip and remove existing vegetation, topsoil, and any other deleterious materials from the proposed construction areas. Stripped organic materials should be wasted from the site or used to re-vegetate landscaped areas or exposed slopes after completion of grading operations. Prior to the placement of fills, the site should be graded to create a relatively level surface to receive fill, and to provide for a relatively uniform thickness of fill beneath proposed structures. Excavation It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. Excavations into the on-site soils will likely encounter weak and/or saturated soil conditions with possible caving conditions. The soils to be excavated can vary significantly across the site as their classifications are based solely on the materials encountered in widely-spaced exploratory test borings. The contractor should verify that similar conditions exist throughout the proposed area of excavation. If different subsurface conditions are encountered at the time of construction, the actual conditions should be evaluated to determine any excavation modifications necessary to maintain safe conditions. Although evidence of fills or underground facilities such as grease pits, septic tanks, vaults, basements, and utilities was not observed during the site reconnaissance, such features could be encountered during construction. If unexpected underground facilities are encountered, such Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 8 features should be removed, and the excavation thoroughly cleaned prior to backfill placement and/or construction. Any over-excavation that extends below the bottom of foundation elevation should extend laterally beyond all edges of the foundations at least 8 inches per foot of over-excavation depth below the foundation base elevation. The over-excavation should be backfilled to the foundation base elevation in accordance with the recommendations presented in this report. Depending upon depth of excavation and seasonal conditions, surface water infiltration and/or groundwater may be encountered in excavations on the site. It is anticipated that pumping from sumps may be utilized to control water within excavations. The subgrade soil conditions should be evaluated during the excavation process and the stability of the soils determined at that time by the contractors’ Competent Person. Slope inclinations flatter than the OSHA maximum values may have to be used. The individual contractor(s) should be made responsible for designing and constructing stable, temporary excavations as required to maintain stability of both the excavation sides and bottom. All excavations should be sloped or shored in the interest of safety following local, and federal regulations, including current OSHA excavation and trench safety standards. As a safety measure, it is recommended that all vehicles and soil piles be kept a minimum lateral distance from the crest of the slope equal to the slope height. The exposed slope face should be protected against the elements Subgrade Preparation After topsoil has been removed from the construction area, the top 10 inches of the exposed ground surface, or bottom of over-excavation should be scarified, moisture conditioned, and recompacted to at least 95 percent of the maximum dry unit weight as determined by ASTM D698 before any new fill or foundation or pavement is placed. If pockets of soft, loose, or otherwise unsuitable materials are encountered at the bottom of the foundation excavations and it is inconvenient to lower the foundations, the proposed foundation elevations may be reestablished by over-excavating the unsuitable soils and backfilling with compacted engineered fill or lean concrete. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 9 After the bottom of the excavation has been compacted, engineered fill can be placed to bring the building pad and pavement subgrade to the desired grade. Engineered fill should be placed in accordance with the recommendations presented in subsequent sections of this report. The stability of the subgrade may be affected by precipitation, repetitive construction traffic or other factors. If unstable conditions develop, workability may be improved by scarifying and drying. Alternatively, over-excavation of wet zones and replacement with granular materials may be used, or crushed gravel and/or rock can be tracked or “crowded” into the unstable surface soil until a stable working surface is attained. Use of fly ash or geosynthetics could also be considered as a stabilization technique. Laboratory evaluation is recommended to determine the effect of chemical stabilization on subgrade soils prior to construction. Lightweight excavation equipment may also be used to reduce subgrade pumping. Fill Materials The on-site soils or approved granular and low plasticity cohesive imported materials may be used as fill material. Bedrock excavated during site development and construction can be reused as fill provided the material is broken down and thoroughly processed to a “soil-like” consistency, with no particles greater than 2 inches in size. The earthwork contractor should expect significant mechanical processing and moisture conditioning of the site soils and/or bedrock will be needed to achieve proper compaction Imported soils (if required) should meet the following material property requirements: Gradation Percent finer by weight (ASTM C136) 4” 100 3” 70-100 No. 4 Sieve 50-100 No. 200 Sieve 50 (max.) Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 10 Soil Properties Values Liquid Limit 35 (max.) Plasticity Index 15 (max.) Other import fill materials types may be suitable for use on the site depending upon proposed application and location on the site, and could be tested and approved for use on a case-by-case basis. Compaction Requirements Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. Item Description Fill lift thickness 9 inches or less in loose thickness when heavy, self- propelled compaction equipment is used 4 to 6 inches in loose thickness when hand-guided equipment (i.e. jumping jack or plate compactor) is used Minimum compaction requirements 95 percent of the maximum dry unit weight as determined by ASTM D698. Moisture content cohesive soil (clay) -1 to +3 % of the optimum moisture content Moisture content cohesionless soil (sand) -3 to +3 % of the optimum moisture content 1. We recommend engineered fill be tested for moisture content and compaction during placement. Should the results of the in-place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved. 2. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction to be achieved without the fill material pumping when proof rolled. 3. Moisture conditioned clay materials should not be allowed to dry out. A loss of moisture within these materials could result in an increase in the material’s expansive potential. Subsequent wetting of these materials could result in undesirable movement. Utility Trench Backfill All trench excavations should be made with sufficient working space to permit construction including backfill placement and compaction. All underground piping within or near the proposed structures should be designed with flexible couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts in foundation walls should be oversized to accommodate differential movements. It is imperative that utility trenches be properly backfilled with relatively clean materials. If utility trenches are backfilled with relatively clean granular material, they should be capped with at least 18 inches of Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 11 cohesive fill in non-pavement areas to reduce the infiltration and conveyance of surface water through the trench backfill. Utility trenches are a common source of water infiltration and migration. All utility trenches that penetrate beneath the building should be effectively sealed to restrict water intrusion and flow through the trenches that could migrate below the building. We recommend constructing an effective clay “trench plug” that extends at least 5 feet out from the face of the building exteriors. The plug material should consist of clay compacted at a water content at or above the soil’s optimum water content. The clay fill should be placed to completely surround the utility line and be compacted in accordance with recommendations in this report. It is strongly recommended that a representative of Terracon provide full-time observation and compaction testing of trench backfill within building and pavement areas. Grading and Drainage Grades must be adjusted to provide effective drainage away from the proposed building during construction and maintained throughout the life of the proposed project. Infiltration of water into foundation excavations must be prevented during construction. Landscape irrigation adjacent to foundations should be minimized or eliminated. Water permitted to pond near or adjacent to the perimeter of the structures (either during or post-construction) can result in significantly higher soil movements than those discussed in this report. As a result, any estimations of potential movement described in this report cannot be relied upon if positive drainage is not obtained and maintained, and water is allowed to infiltrate the fill and/or subgrade. Exposed ground (if any) should be sloped at a minimum of 10 percent grade for at least 10 feet beyond the perimeter of the proposed building, where possible. Locally, flatter grades may be necessary to transition ADA access requirements for flatwork. The use of swales, chases and/or area drains may be required to facilitate drainage in unpaved areas around the perimeter of the building. Backfill against foundations and exterior walls should be properly compacted and free of all construction debris to reduce the possibility of moisture infiltration. After construction of the proposed building and prior to project completion, we recommend verification of final grading be performed to document positive drainage, as described above, has been achieved. Flatwork and pavements will be subject to post-construction movement. Maximum grades practical should be used for paving and flatwork to prevent areas where water can pond. In addition, allowances in final grades should take into consideration post-construction movement of flatwork, particularly if such movement would be critical. Where paving or flatwork abuts the structures, care should be taken that joints are properly sealed and maintained to prevent the infiltration of surface water. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 12 Planters located adjacent to structures should preferably be self-contained. Sprinkler mains and spray heads should be located a minimum of 5 feet away from the building line(s). Low-volume, drip style landscaped irrigation should be used sparingly near the building. Roof drains should discharge on to pavements or be extended away from the structures a minimum of 10 feet through the use of splash blocks or downspout extensions. A preferred alternative is to have the roof drains discharge by solid pipe to storm sewers, a detention pond, or other appropriate outfall. Exterior Slab Design and Construction Exterior slabs on-grade, exterior architectural features, and utilities founded on, or in backfill or the site soils will likely experience some movement due to the volume change of the material. Potential movement could be reduced by: ◼ Minimizing moisture increases in the backfill; ◼ Controlling moisture-density during placement of the backfill; ◼ Using designs which allow vertical movement between the exterior features and adjoining structural elements; and ◼ Placing control joints on relatively close centers. Construction Observation and Testing The earthwork efforts should be monitored under the direction of Terracon. Monitoring should include documentation of adequate removal of vegetation and topsoil, proof rolling, and mitigation of areas delineated by the proof roll to require mitigation. Each lift of compacted fill should be tested, evaluated, and reworked as necessary until approved by Terracon prior to placement of additional lifts. In areas of foundation excavations, the bearing subgrade and exposed conditions at the base of the recommended over-excavation should be evaluated under the direction of Terracon. In the event that unanticipated conditions are encountered, Terracon should prescribe mitigation options. In addition to the documentation of the essential parameters necessary for construction, the continuation of Terracon into the construction phase of the project provides the continuity to maintain Terracon’s evaluation of subsurface conditions, including assessing variations and associated design changes. GROUND IMPROVEMENT Due to comparatively soft clay and loose sand soils encountered to depths up to about 30 feet below existing site grades, we anticipate ground improvement will likely be necessary below Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 13 shallow foundations. Ground improvements could include over-excavation and replacement with properly prepared and compacted fill or rammed aggregate piers below the proposed foundations. Over-Excavation Due to comparatively soft clay and loose sand soils encountered in our borings, we recommend soils below proposed foundations are over-excavated to a depth of at least 3 feet and replaced with properly prepared and compacted fill. On-site soils are suitable for fill below the proposed foundations, provided they meet the standards outline in the Fill Materials section of the Earthwork section of this report. Rammed Aggregate Piers As an alternative to over-excavation below proposed foundations, consideration could be given to ground modification/improvement techniques to improve strength and compressibility characteristics of the foundation soils and to allow for support of the structures on shallow foundations. One approach would include rammed aggregate-pier foundation elements or stone columns to support shallow foundations. Stone columns and rammed aggregate piers consist of a series of drilled holes filled with highly compacted, well graded aggregate to form very stiff, high-density aggregate piers. The stone column and rammed aggregate piers are generally extended below the low strength soil layer to a layer of higher bearing capacity soils or bedrock. Installation of these elements results in significant strengthening and stiffening of the foundation bearing layer to support footings within typical settlement tolerances. Shallow foundations are then constructed over the piers/columns in a conventional manner. Aggregate-pier foundation elements are usually part of the contractor’s design-build system. Therefore, the subsurface exploration information contained in this report should be provided to the foundation contractors for detailed analysis and design and cost information. SHALLOW FOUNDATIONS The proposed building can be supported by a shallow, spread footing foundation system. If the site has been prepared in accordance with the requirements noted in Earthwork, the following design parameters are applicable for shallow foundations. Design Recommendations Description Values Bearing material At least 3 feet of moisture conditioned, properly compacted, over-excavation backfill or supported on rammed aggregate piers Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 14 Description Values Maximum net allowable bearing pressure 1,2 Structural Fill: 2,000 psf Native Soil: 1,500 psf Minimum foundation dimensions Columns: 30 inches Continuous: 18 inches Lateral earth pressure coefficients 3 Structural fill: Active, Ka = 0.17 Passive, Kp = 5.8 At-Rest, Ko = 0.29 Native soil: Active, Ka = 0.36 Passive, Kp = 2.8 At-rest, Ko = 0.53 Sliding coefficient 3 (µ) Structural fill: 0.6 Native soils: 0.42 Moist soil unit weight (ɣ) Structural fill: 135 pcf Native soils: 110 pcf Minimum embedment depth below finished grade 4 30 inches Estimated total movement 5 About 1 inch Estimated differential movement 5 About ½ to ¾ of total movement 1. The recommended maximum net allowable bearing pressure assumes any unsuitable fill or soft or loose soils, if encountered, will be over-excavated and replaced with properly compacted engineered fill. The design bearing pressure applies to a dead load plus design live load condition. The design bearing pressure may be increased by one-third when considering total loads that include wind or seismic conditions. 2. The design bearing pressure applies to shallow foundations supported on over-excavation, if rammed aggregate piers are used to support the proposed structure increase bearing capacity is likely and additional analysis and collaboration with the rammed aggregate pier contractor will be necessary. 3. The lateral earth pressure coefficients and sliding coefficients are ultimate values and do not include a factor of safety. The foundation designer should include the appropriate factors of safety. 4. For frost protection and to reduce the effects of seasonal moisture variations in the subgrade soils. The minimum embedment depth is for perimeter footings beneath unheated areas and is relative to lowest adjacent finished grade, typically exterior grade. Interior column pads in heated areas should bear at least 12 inches below the adjacent grade (or top of the floor slab) for confinement of the bearing materials and to develop the recommended bearing pressure. 5. The estimated movements presented above are based on the assumption that the maximum footing size is 6 feet for column footings and 1.5 feet for continuous footings. Larger foundation footprints will likely require reduced net allowable soil bearing pressures to reduce risk for potential settlement. Footings should be proportioned to reduce differential foundation movement. As discussed, total movement resulting from the assumed structural loads is estimated to be on the order of about 1 inch. Additional foundation movements could occur if water from any source infiltrates the foundation soils; therefore, proper drainage should be provided in the final design and during construction and throughout the life of the structure. Failure to maintain the proper drainage as recommended in the Grading and Drainage section of the Earthwork section of this report will nullify the movement estimates provided above. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 15 Construction Considerations To reduce the potential of “pumping” and softening of the foundation soils at the foundation bearing level and the requirement for corrective work, we suggest the foundation excavation for the building be completed remotely with a track-hoe operating outside of the excavation limits. Spread footing construction should only be considered if the estimated foundation movement can be tolerated. Subgrade soils beneath footings should be moisture conditioned and compacted as described in the Earthwork section of this report. The moisture content and compaction of subgrade soils should be maintained until foundation construction. Footings and foundation walls should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. Unstable subgrade conditions are anticipated as excavations approach the groundwater surface. Unstable surfaces will need to be stabilized prior to backfilling excavations and/or constructing the building foundation, floor slab and/or project pavements. The use of angular rock, recycled concrete and/or gravel pushed or “crowded” into the yielding subgrade is considered suitable means of stabilizing the subgrade. The use of geogrid materials in conjunction with gravel could also be considered and could be more cost effective. Unstable subgrade conditions should be observed by Terracon to assess the subgrade and provide suitable alternatives for stabilization. Stabilized areas should be proof rolled prior to continuing construction to assess the stability of the subgrade. Foundation excavations should be observed by Terracon. If the soil conditions encountered differ significantly from those presented in this report, supplemental recommendations will be required. SEISMIC CONSIDERATIONS The seismic design requirements for buildings and other structures are based on Seismic Design Category. Site Classification is required to determine the Seismic Design Category for a structure. The Site Classification is based on the upper 100 feet of the site profile defined by a weighted average value of either shear wave velocity, standard penetration resistance, or undrained shear strength in accordance with Section 20.4 of ASCE 7 and the International Building Code (IBC). Based on the soil/bedrock properties encountered at the site and as described on the exploration logs and results, it is our professional opinion that the Seismic Site Classification is D. Subsurface explorations at this site were extended to a maximum depth of 30 feet. The site properties below the boring depth to 100 feet were estimated based on our experience and knowledge of geologic conditions of the general area. Additional deeper borings or geophysical testing may be performed to confirm the conditions below the current boring depth. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 16 FLOOR SLABS A slab-on-grade may be utilized for the interior floor system for the proposed building provided the native clay soils are over-excavated to a depth of at least 4 feet, moisture conditioned, and compacted on-site soils. If the estimated movement cannot be tolerated, a structurally-supported floor system, supported independent of the subgrade materials, is recommended. Subgrade soils beneath interior and exterior slabs and at the base of the over-excavation should be scarified to a depth of at least 10 inches, moisture conditioned and compacted. The moisture content and compaction of subgrade soils should be maintained until slab construction. Floor System - Design Recommendations Even when bearing on properly prepared soils, movement of the slab-on-grade floor system is possible should the subgrade soils undergo an increase in moisture content. We estimate movement of about 1 inch is possible. If the owner cannot accept the risk of slab movement, a structural floor should be used. If conventional slab-on-grade is utilized, the subgrade soils should be over-excavated and prepared as presented in the Earthwork section of this report. For structural design of concrete slabs-on-grade subjected to point loadings, a modulus of subgrade reaction of 100 pounds per cubic inch (pci) may be used for floors supported on re- compacted existing soils at the site. A modulus of 200 pci may be used for floors supported on at least 1 foot of non-expansive, imported granular fill. Additional floor slab design and construction recommendations are as follows: ◼ Positive separations and/or isolation joints should be provided between slabs and all foundations, columns, or utility lines to allow independent movement. ◼ Control joints should be saw-cut in slabs in accordance with ACI Design Manual, Section 302.1R-37 8.3.12 (tooled control joints are not recommended) to control the location and extent of cracking. ◼ Interior utility trench backfill placed beneath slabs should be compacted in accordance with the recommendations presented in the Earthwork section of this report. ◼ Floor slabs should not be constructed on frozen subgrade. ◼ Other design and construction considerations, as outlined in the ACI Design Manual, Section 302.1R are recommended. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 17 Floor Systems - Construction Considerations Movements of slabs-on-grade using the recommendations discussed in previous sections of this report will likely be reduced and tend to be more uniform. The estimates discussed above assume that the other recommendations in this report are followed. Additional movement could occur should the subsurface soils become wetted to significant depths, which could result in potential excessive movement causing uneven floor slabs and severe cracking. This could be due to over watering of landscaping, poor drainage, improperly functioning drain systems, and/or broken utility lines. Therefore, it is imperative that the recommendations presented in this report be followed. For slabs that will support traffic loading, we recommend the slab be designed using the Portland Cement Association method or similar mechanistic stress-based design for concrete slabs. For slabs that will carry significant traffic, we also recommend doweled joints be considered for the slab connections. BELOW-GRADE STRUCTURES Lateral Earth Pressures Below-grade structures or reinforced concrete walls with unbalanced backfill levels on opposite sides should be designed for earth pressures at least equal to those indicated in the following table. Earth pressures will be influenced by structural design of the walls, conditions of wall restraint, methods of construction and/or compaction and the strength of the materials being restrained. Two wall restraint conditions are shown. Active earth pressure is commonly used for design of free-standing cantilever retaining walls and assumes wall movement. The "at-rest" condition assumes no wall movement. The recommended design lateral earth pressures do not include a factor of safety and do not provide for possible hydrostatic pressure on the walls. Earth Pressure Coefficients Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 18 Earth Pressure Conditions Coefficient for Backfill Type Equivalent Fluid Density (pcf) Surcharge Pressure, p1 (psf) Earth Pressure, p2 (psf) Active (Ka) Structural Fill - 0.17 Native Lean Clay - 0.36 22 40 (0.17)S (0.36)S (22)H (40)H At-Rest (Ko) Structural Fill - 0.29 Native Lean Clay - 0.53 38 58 (0.29)S (0.53)S (38)H (58)H Passive (Kp) Structural Fill – 5.8 Native Lean Clay – 2.8 754 308 --- --- --- --- Applicable conditions to the above include: ■ For active earth pressure, wall must rotate about base, with top lateral movements of about 0.002 H to 0.004 H, where H is wall height ■ For passive earth pressure to develop, wall must move horizontally to mobilize resistance ■ Uniform surcharge, where S is surcharge pressure ■ In-situ soil backfill weight a maximum of 110 pcf for native lean clay and 130 pcf for structural fill ■ Horizontal backfill, compacted between 95 and 98 percent of standard Proctor maximum dry density ■ Loading from heavy compaction equipment not included ■ No hydrostatic pressures acting on wall ■ No dynamic loading ■ No safety factor included ■ Ignore passive pressure in frost zone Backfill placed against structures should consist of granular soils or low plasticity cohesive soils. For the granular values to be valid, the granular backfill must extend out and up 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. To calculate the resistance to sliding, a value of 0.42 should be used for native lean clay and 0.6 should be used as the ultimate coefficient of friction between the footing and the underlying soil. PAVEMENTS Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 19 evaluated at the time of pavement construction for signs of disturbance or instability. We recommend the pavement subgrade be thoroughly proof rolled with a loaded tandem-axle dump truck prior to final grading and paving. All pavement areas should be moisture conditioned and properly compacted to the recommendations in this report immediately prior to paving. Pavements – Design Recommendations Design of new privately-maintained pavements for the project has been based on the procedures described by the National Asphalt Pavement Associations (NAPA) and the American Concrete Institute (ACI). We assumed the following design parameters for NAPA flexible pavement thickness design: ◼ Automobile Parking Areas • Class I - Parking stalls and parking lots for cars and pick-up trucks, with Equivalent Single Axle Load (ESAL) up to 7,000 over 20 years ◼ Main Traffic Corridors • Class II – Parking lots with a maximum of 10 trucks per day with Equivalent Single Axle Load (ESAL) up to 27,000 over 20 years (Including trash trucks) ◼ Heavy Load Areas • Class II – Delivery lanes with up to 10 trucks per day with Equivalent Single Axle Load (ESAL) up to 110,000 over 20 years ◼ Subgrade Soil Characteristics • USCS Classification – CL, classified by NAPA as poor We assumed the following design parameters for ACI rigid pavement thickness design based upon the average daily truck traffic (ADTT): ◼ Automobile Parking Areas • ACI Category A: Automobile parking with an ADTT of 1 over 20 years ◼ Main Traffic Corridors • ACI Category A: Automobile parking area and service lanes with an ADTT of up to 10 over 20 years ◼ Heavy Load Areas • ACI Category C: Truck areas with an ADTT of up to 100 over 20 years ◼ Subgrade Soil Characteristics • USCS Classification – CL ◼ Concrete modulus of rupture value of 600 psi We should be contacted to confirm and/or modify the recommendations contained herein if actual traffic volumes differ from the assumed values shown above. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 20 Recommended alternatives for flexible and rigid pavements are summarized for each traffic area as follows: Traffic Area Alternative Recommended Pavement Thicknesses (Inches) Asphaltic Concrete Surface Aggregate Base Course Portland Cement Concrete Total Automobile Parking (NAPA Class I and ACI Category A) A 4 6 - 10 B - - 5 5 Service Lanes (NAPA Class II and ACI Category A) A 6 8 - 14 B - - 6 6 Heavy Load Areas (NAPA Class III and ACI Category C) A 7 10 - 17 B - - 8 8 Aggregate base course (if used on the site) should consist of a blend of sand and gravel which meets strict specifications for quality and gradation. Use of materials meeting Colorado Department of Transportation (CDOT) Class 5 or 6 specifications is recommended for aggregate base course. Aggregate base course should be placed in lifts not exceeding 6 inches and compacted to a minimum of 95 percent of the maximum dry unit weight as determined by ASTM D698. Asphaltic concrete should be composed of a mixture of aggregate, filler and additives (if required) and approved bituminous material. The asphalt concrete should conform to approved mix designs stating the Superpave properties, optimum asphalt content, job mix formula and recommended mixing and placing temperatures. Aggregate used in asphalt concrete should meet particular gradations. Material meeting CDOT Grading S or SX specifications or equivalent is recommended for asphalt concrete. Mix designs should be submitted prior to construction to verify their adequacy. Asphalt material should be placed in maximum 3-inch lifts and compacted within a range of 92 to 96 percent of the theoretical maximum (Rice) density (ASTM D2041). Where rigid pavements are used, the concrete should be produced from an approved mix design with the following minimum properties: Properties Value Compressive strength 4,000 psi Cement type Type I or II portland cement Entrained air content (%) 5 to 8 Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 21 Properties Value Concrete aggregate ASTM C33 and CDOT section 703 Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 minutes from the time the water is added to the mix. Longitudinal and transverse joints should be provided as needed in concrete pavements for expansion/contraction and isolation per ACI 325. The location and extent of joints should be based upon the final pavement geometry. For areas subject to concentrated and repetitive loading conditions (if any) such as dumpster pads, truck delivery docks and ingress/egress aprons, we recommend using a portland cement concrete pavement with a thickness of at least 6 inches underlain by at least 4 inches of granular base. Prior to placement of the granular base, the areas should be thoroughly proof rolled. For dumpster pads, the concrete pavement area should be large enough to support the container and tipping axle of the refuse truck. Pavement performance is affected by its surroundings. In addition to providing preventive maintenance, the civil engineer should consider the following recommendations in the design and layout of pavements: ■ Site grades should slope a minimum of 2 percent away from the pavements; ■ The subgrade and the pavement surface have a minimum 2 percent slope to promote proper surface drainage; ■ Consider appropriate edge drainage and pavement under drain systems; ■ Install pavement drainage surrounding areas anticipated for frequent wetting; ■ Install joint sealant and seal cracks immediately; ■ Seal all landscaped areas in, or adjacent to pavements to reduce moisture migration to subgrade soils; and ■ Placing compacted, low permeability backfill against the exterior side of curb and gutter. Pavements – Construction Considerations Openings in pavement, such as landscape islands, are sources for water infiltration into surrounding pavements. Water collects in the islands and migrates into the surrounding subgrade soils thereby degrading support of the pavement. This is especially applicable for islands with raised concrete curbs, irrigated foliage, and low permeability near-surface soils. The civil design for the pavements with these conditions should include features to restrict or to collect and discharge excess water from the islands. Examples of features are edge drains connected to the storm water collection system or other suitable outlet and impermeable barriers preventing lateral migration of water such as a cutoff wall installed to a depth below the pavement structure. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 22 Pavements – Maintenance Preventative maintenance should be planned and provided for an ongoing pavement management program in order to enhance future pavement performance. Preventive maintenance consists of both localized maintenance (e.g. crack and joint sealing and patching) and global maintenance (e.g. surface sealing). Preventative maintenance is usually the first priority when implementing a planned pavement maintenance program and provides the highest return on investment for pavements. CORROSIVITY At the time this report was prepared, the laboratory testing for water-soluble sulfates had not been completed. We will submit a supplemental section with the testing results and recommendations once the testing has been completed. GENERAL COMMENTS Our analysis and opinions are based upon our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration. Natural variations will occur between exploration point locations or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. Terracon should be retained as the Geotechnical Engineer, where noted in this report, to provide observation and testing services during pertinent construction phases. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations. Our Scope of Services does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken. Our services and any correspondence or collaboration through this system are intended for the sole benefit and exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices with no third-party beneficiaries intended. Any third-party access to services or correspondence is solely for information purposes to support the services provided by Terracon to our client. Reliance upon the services and any work product is limited to our client, and is not intended for third parties. Any use or reliance of the provided information by third parties is done solely at their own risk. No warranties, either express or implied, are intended or made. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable 23 Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly impact excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for specific purposes to obtain the specific level of detail necessary for costing. Site safety, and cost estimating including, excavation support, and dewatering requirements/design are the responsibility of others. If changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing. Responsive ■ Resourceful ■ Reliable ATTACHMENTS Contents: EXPLORATION AND TESTING PROCEDURES SITE LOCATION AND EXPLORATION PLANS EXPLORATION RESULTS SUPPORTING INFORMATION Note: Refer to each individual Attachment for a listing of contents. Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 1 of 2 EXPLORATION AND TESTING PROCEDURES Field Exploration The field exploration program consisted of the following: Number of Borings Boring Depth (feet) Location 8 30 Planned building area 4 10 Planned parking/driveway area Boring Layout and Elevations: We used handheld GPS equipment to locate borings with an estimated horizontal accuracy of +/-20 feet. A ground surface elevation at each boring location was obtained by Terracon by interpolation from a publicly available topographic map. Subsurface Exploration Procedures: We advanced soil borings with a truck-mounted drill rig using continuous-flight, solid-stem augers. Three samples were obtained in the upper 10 feet of each boring and at intervals of 5 feet thereafter. Soil sampling was performed using modified California barrel and/or standard split-barrel sampling procedures. For the standard split-barrel sampling procedure, a standard 2-inch outer diameter split-barrel sampling spoon is driven into the ground by a 140-pound automatic hammer falling a distance of 30 inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration is recorded as the Standard Penetration Test (SPT) resistance value. The SPT resistance values, also referred to as N-values, are indicated on the boring logs at the test depths. For the modified California barrel sampling procedure, a 2½-inch outer diameter split-barrel sampling spoon is used for sampling. Modified California barrel sampling procedures are similar to standard split- barrel sampling procedures; however, blow counts are typically recorded for 6-inch intervals for a total of 12 inches of penetration. The samples were placed in appropriate containers, taken to our soil laboratory for testing, and classified by a geotechnical engineer. In addition, we observed and recorded groundwater levels during drilling observations. Our exploration team prepared field boring logs as part of standard drilling operations including sampling depths, penetration distances, and other relevant sampling information. Field logs included visual classifications of materials encountered during drilling, and our interpretation of subsurface conditions between samples. Final boring logs, prepared from field logs, represent the geotechnical engineer's interpretation, and include modifications based on observations and laboratory test results. Property Disturbance: We backfilled borings with auger cuttings. Our services did not include repair of the site beyond backfilling our boreholes. Excess auger cuttings were dispersed in the Geotechnical Engineering Report Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 2 of 2 general vicinity of the boreholes. Because backfill material often settles below the surface after a period, we recommend checking boreholes periodically and backfilling, if necessary. We can provide this service, or grout the boreholes for additional fees, at your request. Laboratory Testing The project engineer reviewed field data and assigned various laboratory tests to better understand the engineering properties of various soil and bedrock strata. Laboratory testing was conducted in general accordance with applicable or other locally recognized standards. Procedural standards noted in this report are for reference to methodology in general. In some cases, variations to methods are applied as a result of local practice or professional judgement. Testing was performed under the direction of a geotechnical engineer and included the following: ■ Visual classification ■ Moisture content ■ Dry density ■ Atterberg limits ■ Grain-size analysis ■ One-dimensional swell ■ Water-soluble sulfates ■ Unconfined compressive strength Our laboratory testing program includes examination of soil samples by an engineer. Based on the material’s texture and plasticity, we described and classified soil samples in accordance with the Unified Soil Classification System (USCS). Soil and bedrock samples obtained during our field work will be disposed of after laboratory testing is complete unless a specific request is made to temporarily store the samples for a longer period of time. Bedrock samples obtained had rock classification conducted using locally accepted practices for engineering purposes. Boring log rock classification is determined using the Description of Rock Properties. Responsive ■ Resourceful ■ Reliable SITE LOCATION AND EXPLORATION PLANS Contents: Site Location Plan Exploration Plan Note: All attachments are one page unless noted above. SITE LOCATION Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Note to Preparer: This is a large table with outside borders. Just click inside the table above this text box, then paste your GIS Toolbox image. When paragraph markers are turned on you may notice a line of hidden text above and outside the table – please leave that alone. Limit editing to inside the table. The line at the bottom about the general location is a separate table line. You can edit it as desired, but try to keep to a single line of text to avoid reformatting the page. SITE LOCA TION DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS EXPLORATION PLAN Precision Technology Warehouse ■ Fort Collins, Colorado June 5, 2020 ■ Terracon Project No. 20205049 Note to Preparer: This is a large table with outside borders. Just click inside the table above this text box, then paste your GIS Toolbox image. When paragraph markers are turned on you may notice a line of hidden text above and outside the table – please leave that alone. Limit editing to inside the table. The line at the bottom about the general location is a separate table line. You can edit it as desired, but try to keep to a single line of text to avoid reformatting the page. EXPLORATION P LAN DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS EXPLORATION RESULTS Contents: GeoModel (3 pages) Boring Logs (12 pages) Atterberg Limits Grain Size Distribution (3 pages) Consolidation/Swell (6 pages) Unconfined Compressive Strength (2 pages) Note: All attachments are one page unless noted above. 4,880 4,885 4,890 4,895 4,900 4,905 4,910 4,915 ELEVATION (MSL) (feet) Precision Technology Fort Collins, CO Terracon Project No. 20205049 Layering shown on this figure has been developed by the geotechnical engineer for purposes of modeling the subsurface conditions as required for the subsequent geotechnical engineering for this project. Numbers adjacent to soil column indicate depth below ground surface. NOTES: B1 B2 B3 P1 GEOMODEL This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions. Groundwater levels are temporal. The levels shown are representative of the date and time of our exploration. Significant changes are possible over time. Water levels shown are as measured during and/or after drilling. In some cases, boring advancement methods mask the presence/absence of groundwater. See individual logs for details. First Water Observation Model Layer Layer Name General Description Sandy lean clay to clayey sand interlayered with silty sand. Lean clay ranges from soft to stiff, silty sand is typically loose to medium dense. 1 2 Well graded sand with silt and gravel, medium dense 3 Lean clay with sand, medium stiff to stiff Interlayered lean clay with sand to clayey sand and well graded sand with silt and gravel. Lean clay ranges from medium stiff to stiff, sand ranges from loose to medium dense. 4 Claystone bedrock, firm to very, some highly weathered 5 bedrock in the upper 5 feet. LEGEND Vegetative Layer Sandy Lean Clay Sandy Lean Clay with Gravel Bedrock Silty Sand Weathered Rock Interlayered silt and clay Well graded sand Lean clay Interlayered lean clay and sand Bedrock 1 4 5 4,875 4,880 4,885 4,890 4,895 4,900 4,905 4,910 4,915 ELEVATION (MSL) (feet) Precision Technology Fort Collins, CO Terracon Project No. 20205049 Layering shown on this figure has been developed by the geotechnical engineer for purposes of modeling the subsurface conditions as required for the subsequent geotechnical engineering for this project. Numbers adjacent to soil column indicate depth below ground surface. NOTES: B4 B6 B7 B8 GEOMODEL This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions. Groundwater levels are temporal. The levels shown are representative of the date and time of our exploration. Significant changes are possible over time. Water levels shown are as measured during and/or after drilling. In some cases, boring advancement methods mask the presence/absence of groundwater. See individual logs for details. First Water Observation Model Layer Layer Name General Description Sandy lean clay to clayey sand interlayered with silty sand. Lean clay ranges from soft to stiff, silty sand is typically loose to medium dense. 1 2 Well graded sand with silt and gravel, medium dense 3 Lean clay with sand, medium stiff to stiff Interlayered lean clay with sand to clayey sand and well graded sand with silt and gravel. Lean clay ranges from medium stiff to stiff, sand ranges from loose to medium dense. 4 Claystone bedrock, firm to very, some highly weathered 5 bedrock in the upper 5 feet. LEGEND Vegetative Layer Sandy Lean Clay Silty Sand Lean Clay with Sand Sandy Lean Clay with Gravel Bedrock Weathered Rock Clayey Sand Well-graded Sand with Silt Interlayered silt and clay Well graded sand Lean clay Interlayered lean clay 4,875 4,880 4,885 4,890 4,895 4,900 4,905 4,910 ELEVATION (MSL) (feet) Precision Technology Fort Collins, CO Terracon Project No. 20205049 Layering shown on this figure has been developed by the geotechnical engineer for purposes of modeling the subsurface conditions as required for the subsequent geotechnical engineering for this project. Numbers adjacent to soil column indicate depth below ground surface. NOTES: B5 P2 P3 P4 GEOMODEL This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions. Groundwater levels are temporal. The levels shown are representative of the date and time of our exploration. Significant changes are possible over time. Water levels shown are as measured during and/or after drilling. In some cases, boring advancement methods mask the presence/absence of groundwater. See individual logs for details. First Water Observation Model Layer Layer Name General Description Sandy lean clay to clayey sand interlayered with silty sand. Lean clay ranges from soft to stiff, silty sand is typically loose to medium dense. 1 2 Well graded sand with silt and gravel, medium dense 3 Lean clay with sand, medium stiff to stiff Interlayered lean clay with sand to clayey sand and well graded sand with silt and gravel. Lean clay ranges from medium stiff to stiff, sand ranges from loose to medium dense. 4 Claystone bedrock, firm to very, some highly weathered 5 bedrock in the upper 5 feet. LEGEND Vegetative Layer Sandy Lean Clay Silty Sand Lean Clay with Sand Bedrock Clayey Sand Well-graded Sand with Gravel Interlayered silt and clay Well graded sand Lean clay Interlayered lean clay and sand Bedrock 1 3 4-2-2 N=4 4-4 1-1-1 N=2 6-4 2-4-6 N=10 2-2-2 N=4 12-18-32 N=50 0/500 64 15 15 20 21 25 23 23 114 107 31-10-21 VEGETATIVE LAYER, approximately 6 inches SANDY LEAN CLAY (CL), brown to light brown, medium stiff with sand and gravel, tan to light brown, loose INTERLAYERED LEAN CLAY WITH SAND AND WELL GRADED SAND WITH GRAVEL, tan to light brown and light/orange brown stiff/loose soft/loose CLAYSTONE, light brown with gray, medium hard to hard Boring Terminated at 30.5 Feet 0.5 14.0 26.0 30.5 4911.5 4898 4886 4881.5 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 FIELD TEST RESULTS SWELL / LOAD (%/psf) UNCONFINED 7-8 3-2-1 N=3 5-6 5-6-5 N=11 4-6-8 N=14 3-4-5 N=9 3-5 53 42 10 14 8 14 23 23 21 99 35-11-24 NP VEGETATIVE LAYER, approximately 6 inches SANDY LEAN CLAY (CL), with gravel, brown to light/orange brown, soft to medium stiff SILTY SAND (SM), red brown, loose INTERLAYERED LEAN CLAY WITH SAND AND WELL GRADED SAND WITH GRAVEL, tan to light brown and light/orange brown stiff/medium dense stiff/loose Boring Terminated at 30 Feet 0.5 8.0 14.0 30.0 4912.5 4905 4899 4883 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 4-6 2-2-2 N=4 4-9 3-5-9 N=14 2-3-4 N=7 6-8-7 N=15 4-6 -0.1/1,000 21 56 14 17 15 23 18 26 98 98 93 34-17-17 VEGETATIVE LAYER, approximately 6 inches SANDY LEAN CLAY (CL), brown, medium stiff SILTY SAND, light brown to pinkish brown with white, loose interlayered with lean clay, red brown SANDY LEAN CLAY, trace gravel, stiff INTERLAYERED LEAN CLAY WITH SAND AND WELL GRADED SAND WITH GRAVEL, tan to light brown and light/orange brown stiff/medium dense medium stiff/loose very stiff/medium dense WEATHERED CLAYSTONE, gray with tan, completely weathered, stiff Boring Terminated at 30 Feet 0.5 2.5 9.0 14.0 29.5 30.0 4911.5 4909.5 4903 4898 4882.5 4882 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 1-1-4 N=5 5-7 3-5-6 N=11 4-7 1-5-6 N=11 4-8-16 N=24 31-50/2" 43 11 14 18 22 19 24 18 106 107 138 34-10-24 VEGETATIVE LAYER, approximately 4 inches SANDY LEAN CLAY, brown, medium stiff SILTY SAND, light brown to pinkish brown with white, loose interlayered with lean clay, brown to orange brown LEAN CLAY WITH SAND, tan with gray and black, stiff INTERLAYERED CLAYEY SAND AND WELL GRADED SAND WITH GRAVEL (SC), light/orange brown medium stiff/loose CLAYSTONE, tan to orange brown with gray, firm to very hard Boring Terminated at 29.8 Feet 0.4 2.5 7.0 17.0 24.0 29.8 4909.5 4907.5 4903 4893 4886 4880 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 FIELD TEST 4-5-5 N=10 8-12 3-6-9 N=15 5-6 4-3-2 N=5 4-5-5 N=10 16-25-39 N=64 3930 77 13 13 18 19 17 18 20 115 111 37-9-28 VEGETATIVE LAYER, approximately 6 inches SANDY LEAN CLAY, brown, medium stiff to stiff SILTY SAND, light brown to pinkish brown with white, medium dense interlayered with lean clay, red/orange brown LEAN CLAY WITH SAND (CL), tan with light brown/white tan to light brown with gray, black and light gray/white, medium stiff stiff CLAYSTONE, tan with gray, medium hard to hard Boring Terminated at 30.5 Feet 0.5 2.5 6.0 26.5 30.5 4907.5 4905.5 4902 4881.5 4877.5 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 FIELD TEST RESULTS SWELL / LOAD 4-6 5-6-6 N=12 2-3 3-4-6 N=10 4-5-5 N=10 2-3-4 N=7 8-18-32 N=50 -0.1/1,000 49 64 16 16 16 27 24 25 20 94 112 38-22-16 36-11-25 VEGETATIVE LAYER, approximately 6 inches SANDY LEAN CLAY, brown to red brown, medium stiff SILTY SAND, light tan/pink to white, loose SANDY LEAN CLAY (CL), with gravel, light brown with white/pink, medium stiff to stiff orange/red brown INTERLAYERED LEAN CLAY WITH SAND AND WELL GRADED SAND WITH GRAVEL, tan to light brown and light/orange brown, medium stiff/loose to medium dense CLAYSTONE, tan with gray, medium hard to hard Boring Terminated at 30.5 Feet 0.5 2.5 3.0 13.0 27.0 30.5 4912.5 4910.5 4910 4900 4886 4882.5 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 3-3-3 N=6 3-4 2-3-4 N=7 5-6 5-8-11 N=19 5-7 11-12-12 N=24 +0.7/500 1090 77 13 15 23 20 9 21 24 102 106 110 35-12-23 VEGETATIVE LAYER, approximately 4 inches LEAN CLAY WITH SAND (CL), light/orange brown with white, medium stiff SANDY LEAN CLAY, orange to red brown, medium stiff WEATHERED CLAYSTONE, tan with gray, weathered to firm Boring Terminated at 30.5 Feet 0.4 9.0 14.0 30.5 4911.5 4903 4898 4881.5 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 FIELD TEST RESULTS SWELL / LOAD (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES 5-6-6 N=12 7-11 6-8-5 N=13 3-7 3-3-5 N=8 3-5-6 N=11 17-21-31 N=52 7 10 13 2 20 21 27 19 98 107 NP VEGETATIVE LAYER, approximately 4 inches CLAYEY SAND, with gravel, brown to red brown with white, medium dense SILTY SAND, trace gravel and clay, tan/pink brown with white, medium dense WELL GRADED SAND WITH SILT (SW-SM), red brown, medium dense LEAN CLAY WITH SAND, tan to light brown and gray, medium stiff to stiff CLAYSTONE, tan and gray, medium hard to hard Boring Terminated at 30.5 Feet 0.4 4.5 8.0 15.0 26.0 30.5 4908.5 4904.5 4901 4894 4883 4878.5 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 25 30 FIELD TEST RESULTS SWELL / LOAD 3-5 3-5 2-1-2 N=3 +0.8/150 66 16 14 16 110 107 36-13-23 VEGETATIVE LAYER, approximately 6 inches SANDY LEAN CLAY (CL), brown to light /orange brown, medium stiff INTERLAYERED LEAN CLAY WITH SAND AND WELL GRADED SAND WITH GRAVEL, light/orange brown, medium stiff/loose Boring Terminated at 10.5 Feet 0.5 8.0 10.5 4911.5 4904 4901.5 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 FIELD TEST RESULTS SWELL / LOAD (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.5188° Longitude: -105.0136° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4912 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 7-6 4-4 10-7-10 N=17 6 42 8 4 104 103 31-12-19 VEGETATIVE LAYER, approximately 6 inches CLAYEY SAND (SC), trace gravel and clay, light brown to orange brown with white, loose WELL GRADED SAND WITH GRAVEL, red brown, medium dense Boring Terminated at 10.5 Feet 0.5 8.0 10.5 4907.5 4900 4897.5 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 FIELD TEST RESULTS SWELL / LOAD (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.5188° Longitude: -105.0125° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4908 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 BORING LOG NO. P2 CLIENT: Eldon James Corporation 4-5 4-4 2-3-5 N=8 +0.9/150 13 61 14 18 102 101 34-10-24 VEGETATIVE LAYER, approximately 3 inches SANDY LEAN CLAY (CL), brown, medium stiff SILTY SAND, trace clay, light brown to pinkish brown with white, loose interlayered with lean clay, brown SANDY LEAN CLAY, tan, medium stiff Boring Terminated at 10.5 Feet 0.3 2.5 7.0 10.5 4906.5 4904.5 4900 4896.5 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 FIELD TEST RESULTS SWELL / LOAD (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.5185° Longitude: -105.0124° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4907 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 9-10 7-12 5-9-11 N=20 9 44 11 15 106 102 33-11-22 VEGETATIVE LAYER, approximately 6 inches CLAYEY SAND (SC), orange/light brown, medium dense light brown to pinkish brown LEAN CLAY WITH SAND, tan with gray, very stiff Boring Terminated at 10.5 Feet 0.5 6.0 10.5 4907.5 4902 4897.5 Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 FIELD TEST RESULTS SWELL / LOAD (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.5178° Longitude: -105.0125° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4908 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 BORING LOG NO. P4 CLIENT: Eldon James Corporation 0 10 20 30 40 50 60 0 20 40 60 80 100 CL or OL CH or OH ML or OL MH or OH "U" Line "A" Line ATTERBERG LIMITS RESULTS ASTM D4318 P L A S T I C I T Y I N D E X LIQUID LIMIT PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/3/20 31 35 NP 34 34 37 38 36 35 NP 36 31 34 33 10 11 NP 17 10 9 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 100 10 1 0.1 0.01 0.001 30 40 1.5 50 6 8 200 4 10 14 1 3/4 1/2 60 GRAIN SIZE IN MILLIMETERS PERCENT FINER BY WEIGHT U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 4 3/8 3 3 100 140 2 GRAIN SIZE DISTRIBUTION ASTM D422 / ASTM C136 6 16 20 PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 medium B1 B2 B2 B3 B4 coarse fine coarse fine COBBLES GRAVEL SAND SILT OR CLAY SANDY LEAN CLAY (CL) SANDY LEAN CLAY (CL) SILTY SAND (SM) SANDY LEAN CLAY (CL) 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 100 10 1 0.1 0.01 0.001 30 40 1.5 50 6 8 200 4 10 14 1 3/4 1/2 60 GRAIN SIZE IN MILLIMETERS PERCENT FINER BY WEIGHT U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 4 3/8 3 3 100 140 2 GRAIN SIZE DISTRIBUTION ASTM D422 / ASTM C136 6 16 20 PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 medium B5 B6 B6 B7 B8 coarse fine coarse fine COBBLES GRAVEL SAND SILT OR CLAY LEAN CLAY with SAND (CL) CLAYEY SAND (SC) SANDY LEAN CLAY (CL) LEAN CLAY with SAND (CL) 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 100 10 1 0.1 0.01 0.001 30 40 1.5 50 6 8 200 4 10 14 1 3/4 1/2 60 GRAIN SIZE IN MILLIMETERS PERCENT FINER BY WEIGHT U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 4 3/8 3 3 100 140 2 GRAIN SIZE DISTRIBUTION ASTM D422 / ASTM C136 6 16 20 PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 medium P1 P2 P3 P4 coarse fine coarse fine COBBLES GRAVEL SAND SILT OR CLAY SANDY LEAN CLAY (CL) CLAYEY SAND (SC) SANDY LEAN CLAY (CL) CLAYEY SAND (SC) 36 -10 -8 -6 -4 -2 0 2 4 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf NOTES: Sample exhibited no movement upon wetting under an applied pressure of 500 psf. SWELL CONSOLIDATION TEST ASTM D4546 PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 B1 4 - 5 ft SANDY LEAN CLAY 114 15 Specimen Identification Classification , pcf WC, % -10 -8 -6 -4 -2 0 2 4 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf NOTES: Sample exhibited 0.1 percent compression upon wetting under an applied pressure of 1,000 psf. SWELL CONSOLIDATION TEST ASTM D4546 PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 B3 9 - 10 ft SANDY LEAN CLAY 98 17 Specimen Identification Classification , pcf WC, % -10 -8 -6 -4 -2 0 2 4 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf NOTES: Sample exhibited 0.1 percent compression upon wetting under an applied pressure of 1,000 psf. SWELL CONSOLIDATION TEST ASTM D4546 PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 B6 9 - 10 ft SANDY LEAN CLAY(CL) 112 16 Specimen Identification Classification , pcf WC, % -10 -8 -6 -4 -2 0 2 4 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf NOTES: Sample exhibited 0.7 percent swell upon wetting under an applied pressure of 500 psf. SWELL CONSOLIDATION TEST ASTM D4546 PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 B7 4 - 5 ft LEAN CLAY with SAND(CL) 102 15 Specimen Identification Classification , pcf WC, % -10 -8 -6 -4 -2 0 2 4 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf NOTES: Sample exhibited 0.8 percent swell upon wetting under an applied pressure of 150 psf. SWELL CONSOLIDATION TEST ASTM D4546 PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 P1 2 - 3 ft SANDY LEAN CLAY 110 16 Specimen Identification Classification , pcf WC, % -10 -8 -6 -4 -2 0 2 4 100 1,000 10,000 AXIAL STRAIN, % PRESSURE, psf NOTES: Sample exhibited 0.9 percent swell upon wetting under an applied pressure of 150 psf. SWELL CONSOLIDATION TEST ASTM D4546 PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 P3 2 - 3 ft SANDY LEAN CLAY(CL) 102 13 Specimen Identification Classification , pcf WC, % 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 0 4 8 12 16 20 AXIAL STRAIN - % UNCONFINED COMPRESSION TEST ASTM D2166 COMPRESSIVE STRESS - psf PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. UNCONFINED WITH PHOTOS 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 111 Strain Rate: in/min Failure Strain: % Calculated Saturation: % Height: in. Diameter: in. SPECIMEN FAILURE PHOTOGRAPH Remarks: Percent < #200 Sieve SAMPLEfeet TYPE: CARS SAMPLE LOCATION: B5 @ 14 - 15 LL PL PI 1967 19 DESCRIPTION: LEAN CLAY WITH SAND Dry Density: pcf Moisture Content: % 14.88 Height / Diameter Ratio: 2.09 Calculated Void Ratio: Undrained Shear Strength: (psf) Unconfined Compressive Strength (psf) Assumed Specific Gravity: 3934 4.01 1.92 SPECIMEN TEST DATA 0 100 200 300 400 500 600 700 800 900 1,000 1,100 0 1 2 3 4 5 6 7 8 AXIAL STRAIN - % UNCONFINED COMPRESSION TEST ASTM D2166 COMPRESSIVE STRESS - psf PROJECT NUMBER: 20205049 SITE: 3486 Precision Drive Fort Collins, CO PROJECT: Precision Technology CLIENT: Eldon James Corporation Denver, CO 1901 Sharp Point Dr, Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. UNCONFINED WITH PHOTOS 20205049 PRECISION TECHNOL_RECOVERED.GPJ TERRACON_DATATEMPLATE.GDT 6/4/20 110 Strain Rate: in/min Failure Strain: % Calculated Saturation: % Height: in. Diameter: in. SPECIMEN FAILURE PHOTOGRAPH Remarks: Percent < #200 Sieve SAMPLEfeet TYPE: CARS SAMPLE LOCATION: B7 @ 24 - 25 LL PL PI 547 21 DESCRIPTION: WEATHERED CLAYSTONE Dry Density: pcf Moisture Content: % 5.28 Height / Diameter Ratio: 2.09 Calculated Void Ratio: Undrained Shear Strength: (psf) Unconfined Compressive Strength (psf) Assumed Specific Gravity: 1093 4.00 1.91 SPECIMEN TEST DATA SUPPORTING INFORMATION Contents: General Notes Unified Soil Classification System Description of Rock Properties Note: All attachments are one page unless noted above. June 5, 2020 Terracon Project No. 20205049 Precision Technology Fort Collins, CO 2,000 to 4,000 Unconfined Compressive Strength Qu, (psf) less than 500 500 to 1,000 1,000 to 2,000 4,000 to 8,000 > 8,000 Modified California Ring Sampler Standard Penetration Test N (HP) (T) (DCP) UC (PID) (OVA) Standard Penetration Test Resistance (Blows/Ft.) Hand Penetrometer Torvane Dynamic Cone Penetrometer Unconfined Compressive Strength Photo-Ionization Detector Organic Vapor Analyzer SAMPLING WATER LEVEL FIELD TESTS Soil classification as noted on the soil boring logs is based Unified Soil Classification System. Where sufficient laboratory data exist to classify the soils consistent with ASTM D2487 "Classification of Soils for Engineering Purposes" this procedure is used. ASTM D2488 "Description and Identification of Soils (Visual-Manual Procedure)" is also used to classify the soils, particularly where insufficient laboratory data exist to classify the soils in accordance with ASTM D2487. In addition to USCS classification, coarse grained soils are classified on the basis of their in-place relative density, and fine-grained soils are classified on the basis of their consistency. See "Strength Terms" table below for details. The ASTM standards noted above are for reference to methodology in general. In some cases, variations to methods are applied as a result of local practice or professional judgment. DESCRIPTIVE SOIL CLASSIFICATION Exploration point locations as shown on the Exploration Plan and as noted on the soil boring logs in the form of Latitude and Longitude are approximate. See Exploration and Testing Procedures in the report for the methods used to locate the exploration points for this project. Surface elevation data annotated with +/- indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area. LOCATION AND ELEVATION NOTES The soil boring logs contained within this document are intended for application to the project as described in this document. Use of these soil boring logs for any other purpose may not be appropriate. GENERAL NOTES DESCRIPTION OF SYMBOLS AND ABBREVIATIONS RELEVANCE OF SOIL BORING LOG Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated. Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible UNIFIED SOIL CLASSIFICATION SYSTEM UNIFIED SOIL CLASSI FICATI ON SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A Soil Classification Group Symbol Group Name B Coarse-Grained Soils: More than 50% retained on No. 200 sieve Gravels: More than 50% of coarse fraction retained on No. 4 sieve Clean Gravels: Less than 5% fines C Cu  4 and 1  Cc  3 E GW Well-graded gravel F Cu  4 and/or [Cc<1 or Cc>3.0] E GP Poorly graded gravel F Gravels with Fines: More than 12% fines C Fines classify as ML or MH GM Silty gravel F, G, H Fines classify as CL or CH GC Clayey gravel F, G, H Sands: 50% or more of coarse fraction passes No. 4 sieve Clean Sands: Less than 5% fines D Cu  6 and 1  Cc  3 E SW Well-graded sand I Cu  6 and/or [Cc<1 or Cc>3.0] E SP Poorly graded sand I Sands with Fines: More than 12% fines D Fines classify as ML or MH SM Silty sand G, H, I Fines classify as CL or CH SC Clayey sand G, H, I Fine-Grained Soils: 50% or more passes the No. 200 sieve Silts and Clays: Liquid limit less than 50 Inorganic: PI  7 and plots on or above “A” line J CL Lean clay K, L, M PI  4 or plots below “A” line J ML Silt K, L, M Organic: Liquid limit - oven dried  0.75 OL Organic clay K, L, M, N Liquid limit - not dried Organic silt K, L, M, O Silts and Clays: Liquid limit 50 or more Inorganic: PI plots on or above “A” line CH Fat clay K, L, M PI plots below “A” line MH Elastic Silt K, L, M Organic: DESCRIPTION OF ROCK PROPERTIES ROCK VERSION 1 WEATHERING Term Description Unweathered No visible sign of rock material weathering, perhaps slight discoloration on major discontinuity surfaces. Slightly weathered Discoloration indicates weathering of rock material and discontinuity surfaces. All the rock material may be discolored by weathering and may be somewhat weaker externally than in its fresh condition. Moderately weathered Less than half of the rock material is decomposed and/or disintegrated to a soil. Fresh or discolored rock is present either as a continuous framework or as corestones. Highly weathered More than half of the rock material is decomposed and/or disintegrated to a soil. Fresh or discolored rock is present either as a discontinuous framework or as corestones. Completely weathered All rock material is decomposed and/or disintegrated to soil. The original mass structure is still largely intact. Residual soil All rock material is converted to soil. The mass structure and material fabric are destroyed. There is a large change in volume, but the soil has not been significantly transported. STRENGTH OR HARDNESS Description Field Identification Uniaxial Compressive Strength, psi (MPa) Extremely weak Indented by thumbnail 40-150 (0.3-1) Very weak Crumbles under firm blows with point of geological hammer, can be peeled by a pocket knife 150-700 (1-5) Weak rock Can be peeled by a pocket knife with difficulty, shallow indentations made by firm blow with point of geological hammer 700-4,000 (5-30) Medium strong Cannot be scraped or peeled with a pocket knife, specimen can be fractured with single firm blow of geological hammer 4,000-7,000 (30-50) Strong rock Specimen requires more than one blow of geological hammer to fracture it 7,000-15,000 (50-100) Very strong Specimen requires many blows of geological hammer to fracture it 15,000-36,000 (100-250) Extremely strong Specimen can only be chipped with geological hammer >36,000 (>250) DISCONTINUITY DESCRIPTION Fracture Spacing (Joints, Faults, Other Fractures) Bedding Spacing (May Include Foliation or Banding) Description Spacing Description Spacing Extremely close < ¾ in (<19 mm) Laminated < ½ in (<12 mm) Very close ¾ in – 2-1/2 in (19 - 60 mm) Very thin ½ in – 2 in (12 – 50 mm) Close 2-1/2 in – 8 in (60 – 200 mm) Thin 2 in – 1 ft. (50 – 300 mm) Moderate 8 in – 2 ft. (200 – 600 mm) Medium 1 ft. – 3 ft. (300 – 900 mm) Wide 2 ft. – 6 ft. (600 mm – 2.0 m) Thick 3 ft. – 10 ft. (900 mm – 3 m) Very Wide 6 ft. – 20 ft. (2.0 – 6 m) Massive > 10 ft. (3 m) Discontinuity Orientation (Angle): Measure the angle of discontinuity relative to a plane perpendicular to the longitudinal axis of the core. (For most cases, the core axis is vertical; therefore, the plane perpendicular to the core axis is horizontal.) For example, a horizontal bedding plane would have a 0-degree angle. ROCK QUALITY DESIGNATION (RQD) 1 Description RQD Value (%) Very Poor 0 - 25 Poor 25 – 50 Fair 50 – 75 Good 75 – 90 Excellent 90 - 100 1. The combined length of all sound and intact core segments equal to or greater than 4 inches in length, expressed as a percentage of the total core run length. Reference: U.S. Department of Transportation, Federal Highway Administration, Publication No FHWA-NHI-10-034, December 2009 Technical Manual for Design and Construction of Road Tunnels – Civil Elements Liquid limit - oven dried  0.75 OH Organic clay K, L, M, P Liquid limit - not dried Organic silt K, L, M, Q Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-inch (75-mm) sieve. B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name. C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay. D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay. E Cu = D60/D10 Cc = 10 60 2 30 D x D (D ) F If soil contains  15% sand, add “with sand” to group name. G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM. H If fines are organic, add “with organic fines” to group name. I If soil contains  15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant. L If soil contains  30% plus No. 200 predominantly sand, add “sandy” to group name. M If soil contains  30% plus No. 200, predominantly gravel, add “gravelly” to group name. N PI  4 and plots on or above “A” line. O PI  4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line. with short term water level observations. Water Initially Encountered Water Level After a Specified Period of Time Water Level After a Specified Period of Time Cave In Encountered STRENGTH TERMS 30 - 50 > 50 5 - 9 10 - 18 Descriptive Term (Consistency) 8 - 15 > 30 Ring Sampler Blows/Ft. 10 - 29 > 99 Medium Hard < 3 3 - 4 19 - 42 2 - 4 BEDROCK Standard Penetration or N-Value Blows/Ft. Very Loose 0 - 3 Very Soft (More than 50% retained on No. 200 sieve.) Density determined by Standard Penetration Resistance (50% or more passing the No. 200 sieve.) Consistency determined by laboratory shear strength testing, field visual-manual procedures or standard penetration resistance RELATIVE DENSITY OF COARSE-GRAINED SOILS 30 - 49 50 - 79 >79 Descriptive Term (Consistency) Firm < 20 Weathered Hard < 30 30 - 49 50 - 89 90 - 119 15 - 30 > 119 Standard Penetration or N-Value Blows/Ft. 0 - 1 4 - 8 Very Hard Ring Sampler Blows/Ft. Ring Sampler Blows/Ft. Soft Medium Stiff Stiff Very Stiff Hard CONSISTENCY OF FINE-GRAINED SOILS Standard Penetration or N-Value Blows/Ft. > 42 Loose Medium Dense Dense Very Dense 7 - 18 19 - 58 Descriptive Term (Density) 0 - 6 4 - 9 59 - 98 _ 20 - 29 31 34 33 65.6 41.8 61.0 43.8 14 6 13 9 P1 P2 P3 P4 23 19 24 22 13 12 10 11 4 - 5 2 - 3 2 - 3 2 - 3 4 - 5 2 - 3 2 - 3 2 - 3 3.8 11.1 0.2 0.8 30.6 47.1 38.8 55.4 19 19 9.5 12.5 0.299 0.156 Boring ID Depth WC (%) LL PL PI Cc Cu Boring ID Depth D100 D60 D30 D10 %Gravel %Sand %Silt %Fines %Clay USCS Classification %Cobbles 0.0 0.0 0.0 0.0 WELL-GRADED SAND with SILT (SW-SM) 37 38 36 35 NP 76.9 49.1 63.7 77.0 6.9 18 16 16 15 2 B5 B6 B6 B7 B8 1.37 28 16 25 23 NP 9 22 11 12 NP 7.32 9 - 10.5 2 - 3 9 - 10 4 - 5 9 - 10.5 9 - 10.5 2 - 3 9 - 10 4 - 5 9 - 10.5 0.0 1.7 0.8 1.3 10.5 23.1 49.2 35.5 21.7 82.6 4.75 12.5 9.5 12.5 19 0.127 1.191 0.516 0.163 Boring ID Depth WC (%) LL PL PI Cc Cu Boring ID Depth D100 D60 D30 D10 %Gravel %Sand %Silt %Fines %Clay USCS Classification %Cobbles 0.0 0.0 0.0 0.0 0.0 CLAYEY SAND (SC) 31 35 NP 34 34 64.2 53.2 42.4 56.0 43.2 20 10 8 21 19 B1 B2 B2 B3 B4 21 24 NP 17 24 10 11 NP 17 10 9 - 10.5 2 - 3 9 - 10 2 - 3 19 - 20.5 9 - 10.5 2 - 3 9 - 10 2 - 3 19 - 20.5 0.5 8.2 0.0 0.1 6.6 35.2 38.7 57.6 43.9 50.2 9.5 19 4.75 9.5 12.5 0.141 0.129 0.091 0.266 Boring ID Depth WC (%) LL PL PI Cc Cu Boring ID Depth D100 D60 D30 D10 %Gravel %Sand %Silt %Fines %Clay USCS Classification %Cobbles 0.0 0.0 0.0 0.0 0.0 22 11 12 NP 13 12 10 11 21 24 NP 17 24 28 16 25 23 NP 23 19 24 22 Boring ID Depth LL PL PI B1 B2 B2 B3 B4 B5 B6 B6 B7 B8 P1 P2 P3 P4 64.2 53.2 42.4 56.0 43.2 76.9 49.1 63.7 77.0 6.9 65.6 41.8 61.0 43.8 Fines 9 - 10.5 2 - 3 9 - 10 2 - 3 19 - 20.5 9 - 10.5 2 - 3 9 - 10 4 - 5 9 - 10.5 4 - 5 2 - 3 2 - 3 2 - 3 CL CL SM CL SC CL SC CL CL SW-SM CL SC CL SC SANDY LEAN CLAY SANDY LEAN CLAY SILTY SAND SANDY LEAN CLAY CLAYEY SAND LEAN CLAY with SAND CLAYEY SAND SANDY LEAN CLAY LEAN CLAY with SAND WELL-GRADED SAND with SILT SANDY LEAN CLAY CLAYEY SAND SANDY LEAN CLAY CLAYEY SAND USCS Description CL-ML Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO No free water observed while drilling WATER LEVEL OBSERVATIONS 1 3 SAMPLE TYPE Drill Rig: CME-75 BORING LOG NO. P3 CLIENT: Eldon James Corporation Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO No free water observed while drilling WATER LEVEL OBSERVATIONS 1 SAMPLE TYPE Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO No free water observed while drilling WATER LEVEL OBSERVATIONS 1 2 SAMPLE TYPE BORING LOG NO. P1 CLIENT: Eldon James Corporation Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO No free water observed while drilling WATER LEVEL OBSERVATIONS 1 4 SAMPLE TYPE (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.5187° Longitude: -105.0128° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4909 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 BORING LOG NO. B8 CLIENT: Eldon James Corporation Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO 18' while drilling WATER LEVEL OBSERVATIONS 1 2 3 5 SAMPLE TYPE WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.5187° Longitude: -105.0132° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4912 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 BORING LOG NO. B7 CLIENT: Eldon James Corporation Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO 13' while drilling WATER LEVEL OBSERVATIONS 3 5 SAMPLE TYPE 25 30 FIELD TEST RESULTS SWELL / LOAD (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.5184° Longitude: -105.013° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4913 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 BORING LOG NO. B6 CLIENT: Eldon James Corporation Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO 13' while drilling WATER LEVEL OBSERVATIONS 1 3 4 5 SAMPLE TYPE (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.518° Longitude: -105.0127° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4908 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 BORING LOG NO. B5 CLIENT: Eldon James Corporation Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO 17' while drilling WATER LEVEL OBSERVATIONS 1 3 5 SAMPLE TYPE RESULTS SWELL / LOAD (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO 17' while drilling WATER LEVEL OBSERVATIONS LOCATION See Exploration Plan Latitude: 40.518° Longitude: -105.0133° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4910 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 BORING LOG NO. B4 CLIENT: Eldon James Corporation Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map 1 3 4 5 SAMPLE TYPE 30 FIELD TEST RESULTS SWELL / LOAD (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.5181° Longitude: -105.014° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4912 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 BORING LOG NO. B3 CLIENT: Eldon James Corporation Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO 17' while drilling WATER LEVEL OBSERVATIONS 1 4 5 SAMPLE TYPE 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO 14' while drilling WATER LEVEL OBSERVATIONS FIELD TEST RESULTS SWELL / LOAD (%/psf) UNCONFINED COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.5184° Longitude: -105.0136° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4913 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 BORING LOG NO. B2 CLIENT: Eldon James Corporation Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 1 4 SAMPLE TYPE COMPRESSIVE STRENGTH (psf) PERCENT FINES WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI LOCATION See Exploration Plan Latitude: 40.5187° Longitude: -105.014° GRAPHIC LOG MODEL LAYER DEPTH ELEVATION (Ft.) Surface Elev.: 4912 (Ft.) Page 1 of 1 Advancement Method: 4-inch solid-stem augers Abandonment Method: Boring backfilled with soil cuttings upon completion. Notes: Project No.: 20205049 Drill Rig: CME-75 BORING LOG NO. B1 CLIENT: Eldon James Corporation Denver, CO Driller: Drilling Engineers, Inc. Boring Completed: 05-30-2020 PROJECT: Precision Technology Elevations obtained from publicly available topographic map See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 3486 Precision Drive Fort Collins, CO SITE: Boring Started: 05-30-2020 1901 Sharp Point Dr, Ste C Fort Collins, CO 14' while drilling WATER LEVEL OBSERVATIONS 1 4 5 SAMPLE TYPE 5 17 6 26.5 30.5 1 2 8 10.5 1 10.5 1 3 6 10.5 and sand Bedrock 1 3 4 5 17 7 17 24 29.8 1 3 4 5 13 3 13 27 30.5 3 5 13 14 30.5 1 2 3 5 18 8 15 26 30.5 14 14 26 30.5 1 4 14 14 30 1 4 5 17 14 29.5 30 1 4 8 10.5 Pavements – Subgrade Preparation On most project sites, the site grading is accomplished relatively early in the construction phase. Fills are typically placed and compacted in a uniform manner. However, as construction proceeds, the subgrade may be disturbed due to utility excavations, construction traffic, desiccation, or rainfall/snow melt. As a result, the pavement subgrade may not be suitable for pavement construction and corrective action will be required. The subgrade should be carefully B-6 13 B-7 13 B-8 18 P-1 Not encountered P-2 Not encountered P-3 Not encountered P-4 Not encountered These observations represent short-term groundwater conditions at the time of and shortly after the field exploration and may not be indicative of other times or at other locations. Groundwater levels can be expected to fluctuate with varying seasonal and weather conditions, and other classification for this site is D. Construction Observation and Testing Close monitoring of the construction operations and implementing drainage recommendations discussed herein will be critical in achieving the intended foundation, slab and pavement performance. We therefore recommend that Terracon be retained to monitor this portion of the work. General Comments This section contains important information about the limitations of this geotechnical engineering report. and flat work will probably increase if modification of the site results in excessive wetting or drying of the expansive clays. Eliminating the risk of movement and cosmetic distress is generally not feasible, but it may be possible to further reduce the risk of movement if significantly more expensive measures are used during