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Home My WebLink About20241347.tiff(+A Kumar & Associates, Inc. Geotechnical and Materials Engineers and Environmental Scientists An Employee Owned Company 2390 South Lipan Street Denver, CO 80223 phone: (303) 742-9700 fax: (303) 742-9666 email: kadenver@kumarusa.com www.kumarusa.com Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado Prepared By: Justin Cupich, P.E. GEOTECHNICAL ENGINEERING STUDY MOUNTAIN PEAK POWER STATION 10001 WELD COUNTY ROAD 55 KEENESBURG / WELD COUNTY, COLORADO Kindle Project No. 31324 Reviewed By: Jos ua L.arker, P.E. Prepared For Mountain Peak Power, LLC 500 Alexander Park Drive, Suite 300 Princeton, NJ 08540 Attention: Thomas Flexon Project No. 23-1-750 January 4, 2024 TABLE OF CONTENTS SUMMARY 1 PURPOSE AND SCOPE OF WORK 2 PROPOSED CONSTRUCTION 2 SITE CONDITIONS 3 GEOLOGIC SETTING 3 SUBSURFACE CONDITIONS 4 LABORATORY TESTING 6 GEOTECHNICAL CONSIDERATIONS 8 SITE GRADING AND EARTHWORK 8 FOUNDATION RECOMMENDATIONS 12 FOUNDATION DYNAMIC ANALYSIS 22 SLABS -ON -GRADE 23 SEISMIC DESIGN CRITERIA 23 SLABS ON GRADE 24 LATERAL EARTH PRESSURES 24 SURFACE DRAINAGE 26 WATER-SOLUBLE SULFATES 26 FIELD THERMAL RESISTIVITY TESTING 27 ELECTRICAL RESISTIVITY AND BURIED METAL CORROSION 27 AGGREGATE -SURFACED ROADWAYS AND YARD AREAS 29 DESIGN AND CONSTRUCTION SUPPORT SERVICES 31 LIMITATIONS 31 FIG. 1 - LOCATION OF EXPLORATORY BORINGS FIG. 2 - LOGS OF EXPLORATORY BORINGS FIG. 3 - LEGEND AND EXPLANATORY NOTES FIGS. 4 through 9 - SWELL -CONSOLIDATION TEST RESULTS FIG. 10 - GRADATION TEST RESULTS FIGS. 11 through 14 - MOISTURE -DENSITY RELATIONSHIPS FIG. 15 - HVEEM-STABILOMETER ETER TEST RESULTS FIGS. 16 through 18- UNCONFINED COMPRESSIVE STRENGTH RESULTS FIGS. 19 through 21- ELECTRICAL RESISTIVITY RESULTS FIG. 22 - LABORATORY RESISTIVITY RESULTS FIGS. 23 through 25- ELECTRICAL RESISTIVITY RESULTS TABLE I - SUMMARY OF LABORATORY TEST RESULTS Kumar & Associates, Inc.® SUMMARY 1 The subsurface conditions encountered in the borings generally consisted of a relatively thin layer of topsoil underlain by naturally deposited (native) overburden soils consisting primarily of cohesive (clay) soils with lenses and zones of native granular soils. The native soils extended to weathered claystone at depths ranging from about 9 to 17 feet in Borings 1 through 4, and to claystone bedrock at depths ranging from about 13 to 18 feet in remaining borings. The weathered claystone in Borings 1 through 4 was underlain by claystone bedrock at depths ranging from about 12.5 to 20 feet. The subsurface conditions encountered in the test pit consisted of a thin layer of topsoil underlain by native granular soils extending to native clay soils at a depth of about 5 feet below exiting grades. Groundwater was not encountered in any of the borings during or shortly after the completion of drilling. Groundwater was also not encountered in the explored depth of the test pit. Stabilized groundwater level measurements were made on December 20, 2023 (8 days after drilling) and encountered groundwater in Boring 3 at a depth of about 22.5 feet below existing grades. Borings 4 and 7 were found to have been backfilled by others and the remaining borings were found to be dry during the stabilized groundwater level measurements. Shallow foundations, including gravel pads, spread footings, and mat/thickened slabs should be feasible. Soil -supported slabs are also considered feasible. Shallow foundations and soil -supported slabs should be supported on structural fill extending to native undisturbed soils as described here in. Allowable bearing/contact pressures and an associated increase for transient loads for shallow foundations are presented herein. 3 Short drilled piers/footings and deep drilled piers extending into the bedrock and installed as recommended herein should also feasible. Recommendations for short drilled footings and deep drilled piers are provided herein. Recommendations for helical pier foundations are also provided herein. 4 A thickness of 10 inches should be considered for aggregate surfacing for unpaved roadways and other areas accessed by vehicles. Greater thicknesses should be used in turn -around areas and areas that may be used routinely by heavier vehicles. A thickness greater than 12 inches may be preferred for any heavily -used access driveways. 5 The onsite soils, exclusive of topsoil, should be suitable for use as general site grading fill and as structural fill beneath foundations and floor slabs. The majority of existing native soils are relatively dry, and addition of water may be necessary to properly moisture -condition the soils. Claystone bedrock should not be reused as structural fill. Kumar & Associates, Inc.® 2 PURPOSE AND SCOPE OF WORK This report presents the results of a geotechnical engineering study performed for the proposed Mountain Peak Power Station to be constructed at 10001 Weld Couty Road (WCR) 55 in Keenesburg/Weld County, Colorado. The project site is shown on Fig. 1. The study was conducted in general accordance with the scope of work presented in our Proposal No. P-23- 923 to Mountain Peak Power, LLC and Stanley Consultants, Inc., dated November 28, 2023. A field exploration program consisting of exploratory borings was conducted to obtain information on subsurface conditions. Samples of the soils and bedrock materials obtained during the field exploration program were tested in the laboratory to determine their classification and engineering characteristics. The results of the field exploration and laboratory testing programs were analyzed to develop geotechnical engineering recommendations for design and construction of the proposed power station. This report has been prepared to summarize the data obtained during this study and to present our conclusions and recommendations based on the proposed construction and the subsurface conditions encountered. Design parameters and a discussion of geotechnical engineering considerations related to construction of the proposed power station are included in the report. PROPOSED CONSTRUCTION Based on the information provided to us, site development will consist of the construction of a power station located as previously described in Keenesburg/Weld County, Colorado. The power station will include six LM2500Xpress GE combustion turbines and other ancillary equipment. The compressors will have a footprint area of 92 ft by 35 ft and will weigh up to 350 kips each. Six stacks will be constructed and will have dimensions of 9 feet in diameter with heights of 80 feet. A transformer with a footprint of 15 ft by 18 ft and a weight of about 90 kips will also be constructed. We assume aggregate -surfaced roadways and yard areas may also be constructed. Based on the existing topography of the site, we anticipate site grading will consist of minor cuts and fills to achieve finished grade with no need for engineered retaining walls or grade separation solutions. We assume various equipment and building foundation types will be used for the project including spread footing, mats, gravel pads, drilled footings/short drilled piers, and drilled piers. Kumar & Associates, Inc.® If the proposed construction varies significantly from that described above or depicted in this report, we should be notified to reevaluate the recommendations provided in this report. SITE CONDITIONS The project site is a roughly 18 -acre, rectangular -shaped, property. The southern portion of the site, except the western portion, is currently occupied by a substation and its associated equipment. The northern portion of the site will be developed to construct the proposed power station. Three dilapidated, old single -story structures are present at the site. We understand these structures will be removed prior to construction. The site is generally surrounded by other oil/gas facilities or agricultural properties. The site is bounded on the north and west by undeveloped property, on the west by WCR 55, and on the south by WCR 22. The GPS coordinates for the approximate center of the new power station site are: 40.147326°N, - 104.548963°W. Based on historical aerial photographs, the three previously mentioned single -story structures have been on site since at least 1999. The existing substation on the southern portion of the site appears to have been built between later 2018 and late 2019. Based on available topographical information and site boring relative elevation measurements, the site is gently sloping down from northeast to southwest with about 10 feet or less of relief across the proposed development area. GEOLOGIC SETTING The public geologic map "Notes on the Denver Basin geologic maps: Bedrock geology, structure, and isopach maps of the Upper Cretaceous to Paleogene strata between Greeley and Colorado Springs, Colorado" (Dechesne, Marieke, Raynolds, R.G., Barkmann, P.E., and Johnson, K.R., 2011) depict the project site area as underlain by the Denver Basin Group D1 Sequence ((Claystone and sandstone) (Cretaceous to Paleocene)). A portion of that geologic map is reproduced below with the approximate project site marked by the blue indicator near the center of the map. Kumar & Associates, Inc.® SUBSURFACE CONDITIONS The field exploration program for the project was performed on December 11 and 12, 2023. Eight (8) exploratory borings and a single test pit were drilled/excavated at locations selected by Mountain Peak Power, LLC. The approximate locations of the borings and the test pit are shown on Fig. 1. The borings were drilled to a depth of about 30 feet and the test pit was excavated to a depth of about 8 feet below existing grades to explore subsurface conditions and to obtain samples for laboratory testing. Logs of the exploratory borings and test pit are presented on Fig. 2 with a legend and explanatory notes for the logs presented on Fig. 3. The borings were advanced into the overburden soils and bedrock with 4 -inch -diameter, continuous -flight, solid -stem augers, and were logged by a representative of Kumar & Associates, Inc (K+A). Samples of the soils and bedrock were obtained with a 2 -inch I.D. California -liner sampler driven into the various strata with blows from a 140 -pound hammer falling 30 inches. Sampling with the California -liner sampler is similar to the standard penetration test described by ASTM Method D1586. Sampler penetration resistance values (blow counts), when properly evaluated, indicate the relative density or consistency of the soils. Depths at which the samples were obtained and the penetration resistance values are shown adjacent to the boring logs on Fig. 2. Kumar & Associates, Inc.® 5 The test pit was excavated using a John Deere mini -excavator with an 18 -inch -wide toothed bucket, and were logged by a representative of K+A. Small disturbed samples of the soils were obtained from the pit using conventional hand tools. Subsurface Soil Conditions: The subsurface conditions encountered in the borings generally consisted of a relatively thin layer of topsoil underlain by naturally deposited (native) overburden soils consisting primarily of cohesive (clay) soils with lenses and zones of native granular soils. The native soils extended to weathered claystone at depths ranging from about 9 to 17 feet in Borings 1 through 4, and to claystone bedrock at depths ranging from about 13 to 18 feet in remaining borings. The weathered claystone in Borings 1 through 4 was underlain by claystone bedrock at depths ranging from about 12.5 to 20 feet. The borings were terminated in the bedrock at depths of about 30 feet below existing grades. The subsurface conditions encountered in the test pit consisted of a thin layer of topsoil underlain by native granular soils extending to native clay soils at a depth of about 5 feet below exiting grades. The native clay soils extended to the maximum explored depth of about 8 feet. The native clay soils consisted of lean clay with variable fine- to medium -grained sand content, and were generally slightly moist to moist, and tan to brown. The native granular soils consisted of poorly -graded sand with silt to silty clayey sand that was fine- to medium -grained, slightly moist, contained isolated organics in the near surface soils, and were tan to brown. Based on blow counts, the native clay soils ranged from stiff to very stiff with isolated medium and hard zones. The native granular soils were medium dense. The weathered claystone encountered in Borings 1 through 4 contained a fine-grained sand fraction and was moist and brown to gray -brown. The unweathered claystone bedrock contained a fine-grained sand fraction, low to high plasticity, and isolated silty zones and was generally moist, gray to gray -brown to dark gray with occasional iron oxidation staining and frequent lignite inclusions (small dots of lignite). Based on blow counts, the claystone bedrock ranged from firm to hard with isolated very hard zones. Groundwater Conditions: Groundwater was not encountered in any of the borings during or shortly after the completion of drilling. The borings were left open to allow for follow-up stabilized groundwater level measurements. Groundwater was also not encountered in the explored depth of the test pit. The test pit was backfilled for safety reasons. Stabilized groundwater level measurements were made on December 20, 2023 (8 days subsequent to drilling) and Kumar & Associates, Inc.® 6 encountered groundwater in Boring 3 at a depth of about 22.5 feet below existing grades. Borings 4 and 7 were found to have been backfilled by others and the remaining borings were found to be dry during the stabilized groundwater level measurements. The open bore holes were backfilled upon completion of these measurements. LABORATORY TESTING Samples obtained from the exploratory borings were visually classified in the laboratory by the project engineer. Laboratory testing was performed on representative samples to evaluate in - situ moisture content and dry unit weight, grain size distribution, liquid and plastic limits, and swell -consolidation behavior. Moisture -density relationships (standard Proctor) test were performed on composite bulk samples of the overburden soils with one Hveem-stabilometer (R - value) test also performed on one of the composite bulk samples. Corrosion testing consisting of minimum electrical soils resistivity, thermal resistivity, pH, and concentration of chlorides was also performed on selected samples. The above testing was performed in accordance with the applicable ASTM standard test procedures and the resistivity testing, both electrical and thermal, was performed in accordance with the Institute of Electrical and Electronics Engineers (IEEE) standard test procedure. The percentage of water-soluble sulfates was evaluated in general accordance with the Colorado Department of Transportation (CDOT) CP-L 2103 test procedure. The results of the laboratory tests are shown to the right of the logs on Fig. 2, plotted graphically on Figs. 4 through 25, and summarized in Table I. Swell -Consolidation: Swell -consolidation (Method B) tests were conducted on representative samples of the native clay soils, claystone bedrock, and one sample of the silty clayey sand soils to evaluate their swell and/or compressibility under loading and when submerged in water. Each sample the prepared and placed in a confining ring between porous discs, subjected to a surcharge pressure of 1,000 psf, and allowed to consolidate before being submerged. The samples were then loaded incrementally to maximum surcharge pressures ranging from 3,000 psf to 20,000 psf. The sample heights were monitored until deformation practically ceased under each load increment. Results of the swell -consolidation tests are presented on Figs. 4 through 9 as plots of the curve of the final strain at each increment of pressure against the log of the pressure. Based on the results of the swell -consolidation testing, the samples of native clay soils exhibited slight additional compression to no movement when wetted. The tested samples of claystone exhibited low to very high swell potential when wetted, and the sample of silty clayey sand Kumar & Associates, Inc.® 7 exhibited moderate additional compression. We believe the slight additional compression exhibited by two of the clay samples is primarily due to sample disturbance and is not indicative of collapse potential. We believe the moderate additional compression exhibited by the silty clayey sand sample is the result of the combined effects of sample disturbance and low in -situ dry density. Index Properties: Samples were classified into categories of similar engineering properties in general accordance with the Unified Soil Classification System. This system is based on index properties, including liquid limit, plasticity index and grain size distribution. Values for in -situ moisture content and dry density, liquid limit and plasticity index, and the percent of soil retained on the U.S. No 4 sieve and percent soil passing the U.S. No. 200 sieve are presented in Table and adjacent to the corresponding sample on the boring logs. The results of laboratory gradation testing performed on a sample of the native granular soils are presented on Fig. 10. Moisture -Density Relationship: Standard Proctor testing (ASTM D698) was performed on 4 composited bulk samples of the native overburden soils obtained from the locations of Boring 2 and the three thermal resistivity test (TRT) locations at depths ranging from about 1 to 5 feet in order to determine the maximum dry density and optimum moisture content of the soils. The results of the standard Proctor test are presented on Figs. 11 through 14. Hveem-Stabilometer: Hveem-Stabilometer (R -value) testing was completed on a composite bulk samples of the anticipated roadway subgrade soils. The R -value is determined at an exudation pressure of 300 psi and is used in the pavement thickness design. The results of the testing are presented on Fig. 15. The testing indicated an R -value of less than 5. Unconfined Compressive Strength: Samples of the claystone bedrock obtained from Borings 1, 6, and 8 at depths of about 24, 19, and 29 feet, respectively, were tested to evaluate the unconfined compressive strength of the bedrock material. The testing indicated compressive strength values of 138, 47.8, and 84.4 psi for bedrock samples obtained from Borings 1, 6, and 8, respectively. The results of the unconfined compressive strength testing are plotted graphically on Figs. 13 through 15. Thermal Resistivity: Remolded laboratory resistivity testing was performed on 3 composite bulk samples obtained the field thermal resistivity testing locations as shown on Fig. 1. The testing was being performed to generate thermal dryout curves for the materials at these locations. The results of thermal resistivity testing are presented on Figs. 23 through 25. Kumar & Associates, Inc.® 8 GEOTECHNICAL CONSIDERATIONS Based on the data obtained from the field exploration and laboratory testing programs, we believe shallow foundations, including spread footings and mat/thickened slabs will be feasible for the majority of the structures with proper subgrade preparation. Shallow drilled piers/footings are also feasible. We understand deeper drilled piers terminating in the bedrock may be used for some to the heavier equipment. Aggregate pads for lighter equipment should also be feasible with proper subgrade preparation. The native overburden soils should generally be suitable for reuse as site grading and structural fill. The claystone bedrock is not suitable for reuse as structural fill. The natural moisture content of the majority of the overburden clay soils appear to be several percent below the optimum moisture content. Accordingly, there will be a high likelihood the materials will require significant quantities of water to achieve proper moisture conditioning. Expansive claystone bedrock was encountered in the borings. As previously stated, the laboratory testing indicated the bedrock samples exhibited low to very high swell potential when wetted. The bedrock was generally encountered at depths greater than about 10 feet below the existing ground surface. Accordingly, we do not anticipate swelling bedrock to be a design consideration for shallow foundations, soil -supported slabs, and aggregate -surfacing. However, if cuts resulting in the bottom of a shallow foundations and/or soil -supported slab being within about 4 feet of the claystone will occur, K+A should be contacted to modify the recommendations presented herein. SITE GRADING AND EARTHWORK Based upon the existing topography, we anticipate finished grades across most of the site are anticipated to be relatively close to existing site grades, with cuts and fills expected to be less than about 5 feet. Permanent Cut and Fill Slopes: The native overburden soils, particularly the granular soils, are anticipated to be moderately erodible. While cut and properly compacted fill slopes above groundwater as steep as 2H:1V should have adequate factors of safety against global instability, surficial instability in the form of sloughing and shallow slumps is likely to result from precipitation, runoff flows, and cycles of freeze/thaw and wetting/drying. Consequently, we recommend permanent cut and fill slopes be designed and constructed more with the intent of limiting significant slope face erosion than deep-seated slope instability. Erosion potential can Kumar & Associates, Inc.® 9 be reduced by constructing flatter slopes, introducing native vegetation, or covering the slopes with a more erosion -resistant gravel or long-term erosion control blankets. Erosion potential can also be reduced by the use of diversion berms, ditches, and other grading measures to mitigate concentrated surface runoff down cut and fill slopes. Flatter slopes may be necessary for cuts in relatively loose granular materials. The risk of slope instability will be significantly increased if seepage from perched groundwater is encountered in cuts. Although not anticipated, if groundwater seepage is anticipated or encountered during construction, a stability analysis should be conducted to determine if the seepage will adversely affect the stability of the cut slope. The ground surface underlying all fills should be carefully prepared by removing all organic matter, scarifying and moisture -conditioning the fill subgrade soils to a depth of 12 inches, and compacting the scarified soils to at least 95% of the standard Proctor (ASTM D698) maximum dry density at moisture contents within 2 percentage points of optimum for predominantly granular soils and within the range of optimum to 3 percentage points above optimum for predominately clay soils, if encountered. New fills should be benched into existing slopes that exceeding 4 horizontal to I vertical. Since cut and fill slopes, if constructed, are expected to be relatively low in height, no formal stability analyses were performed to evaluate the slopes recommended above. Published literature and our experience with similar cuts and fills indicate the recommended slope ratios should have adequate factors of safety. If a detailed stability analysis is required based on the above discussion, we should be notified. Temporary Excavations: We assume temporary site excavations will be constructed by generally over -excavating the side slopes to a stable configuration where enough space is available. All excavations greater than 4 feet in depth should be constructed in accordance with OSHA requirements, as well as state, local and other applicable requirements. OSHA requires excavations or trenching over 20 feet deep, or those extending below the groundwater table, be designed by a registered professional engineer. The native overburden granular soils will classify as OSHA Type C soils and the native clay soils will classify as OSHA Type B soils. Although not anticipated, if unstable soil conditions or groundwater are encountered, the geotechnical engineer should be notified so additional recommendations can be provided, if necessary. Kumar & Associates, Inc.® 10 Excavated slopes may soften or loosen due to construction traffic and erode from surface runoff. Measures to keep surface runoff from excavation slopes, including diversion berms, should be considered. Based on standard penetration blow counts obtained during the field exploration program, standard heavy duty hydraulic equipment should be able to excavate the overburn soils. Excavation Dewatering: Excavations extending to depths greater than about 20 feet may encounter groundwater. Excavations extending below groundwater should be properly dewatered prior to and during the excavation process to help maintain the stability of the excavation side slopes and stable subgrade conditions for foundation and slab construction and structural fill placement. We believe it may be feasible to dewater an excavation extending a foot or so below groundwater using perimeter (and lateral) trenches combined with sumps. The trenches should be sloped to sumps where water can be pumped from the excavation. Dewatering means and methods should be designed and selected by the contractor. Dewatering should maintain the groundwater level at a point at least 2 feet below the bottom of the excavation and maintain that level until backfill extends to or above the stabilized groundwater level. Wells and well -points are generally not suitable to dewater in the native clay soils. Material Specifications: Unless specifically modified in other sections of this report, the following recommended material and compaction requirements are presented for site grading and structural fills on the project site. A geotechnical engineer should evaluate the suitability of all proposed fill materials to be used on the site prior to placement. 1 Structural Fill: Structural fill placed beneath and adjacent to foundation elements and beneath soil -supported slabs and site flatwork should consist of on -site native overburden soils or imported materials with 30 to 75 percent passing the U.S No. 200 sieve, a maximum liquid limit of 35 and a maximum plasticity index of 15. All import soils used as structural fill should also meet the non -expansive swell criteria presented in Item 4 below. 2 General Site Grading Fill: Fill used as general site grading and not placed beneath and adjacent to foundation elements and beneath soil -supported slabs and site flatwork Kumar & Associates, Inc.® 11 should consist of on -site native overburden soils or imported materials meeting the low - swelling criteria presented in Item 4 below. 3 Utility Trench Backfill: Material excavated from the utility and pipe trenches may be used for utility trench backfill provided it does not contain unsuitable material or particles larger than 4 inches. Material Suitability: All fill material should be free of topsoil, vegetation, brush, and other deleterious substances and should not contain rocks, debris or lumps having a diameter of more than 4 inches. Rocks, debris or lumps should be dispersed throughout the fill and "nesting" of these materials should be avoided. The geotechnical engineer should evaluate the suitability of proposed imported fill materials prior to placement, if required. An imported fill source materials may be considered non -expansive if the swell potential for samples remolded to 95% of the standard Proctor (ASTM D698) maximum dry density at optimum moisture content does not exceed 0.5% when wetted under a 200 psf surcharge pressure. Similarly, an import material can be considered low -swelling if the swell potential for samples remolded and wetted as described is less than 1%. Evaluation of potential imported fill sources will require determination of laboratory moisture -density relationships and swell characteristics. Based on the results of laboratory testing, the on -site overburden soils should generally be suitable for use as compacted fill beneath foundations and soil -supported slabs. The majority of on -site soils have relatively low natural moisture contents and will likely require the addition of water to meet the fill compaction criteria recommended herein. Placement and Compaction Specifications: We recommend the following compaction criteria be used on the project: 1 Moisture Content: All fill materials should be compacted as outlined below with moisture contents within the range of optimum to +3 percentage points of the optimum moisture content for clay soils and within 2 percentage points of optimum for granular soils. The contractor should be aware clay or clayey soils placed near the upper end of the moisture content range may become unstable. Additionally, achieving the above Kumar & Associates, Inc.® 12 moisture criteria for on -site soils will require the addition of water to help facilitate compaction and meet the placement criteria recommended herein. Placement and Degree of Compaction: Fill should be placed in maximum 8 -inch loose lifts as necessary, provided proper compaction can be achieved. The following compaction criteria should be followed during construction: Percentage of Maximum Standard Proctor Density Fill Location (ASTM D698) Beneath Spread Footing and Mat Foundations 98% Adjacent to Spread Footing and Mat Foundations 98% Beneath Soil -Supported Slabs 95% Beneath Aggregate Surfacing 95% Utility Trenches 95% All other areas 95% 2 General Subgrade Preparation: Areas receiving new fill should be prepared as recommended in specific sections of this report to provide a uniform base for fill placement. All other areas receiving new fill should be scarified to a depth of at least 8 inches and recompacted to at least 95% of the standard Proctor (ASTM D698) maximum dry density at moisture contents recommended above. Construction Monitoring: We recommend K+A should observe and test fill placement. Structural fills beneath foundations, slabs on grade, tanks, and other structures, as well as compacted fill placed beneath other site facilities, should be observed and tested on a full-time basis. FOUNDATION RECOMMENDATIONS Spread Footings: The design and construction criteria presented below should be observed for a spread footing foundation system. The construction details should be considered when preparing project documents. Spread footings should be placed on a minimum of 1 foot of structural fill extending to undisturbed native overburden soils. Areas of loose or soft material encountered within the foundation excavation should be removed and replaced with structural fill. Structural fill should meet the material and placement requirements outlined in the "Site Grading and Earthwork" section of this report. Structural fill should extend down and out from the edges of the footings at a 1 horizontal to 1 vertical projection. Kumar & Associates, Inc.® 13 2 Footings supported as recommended herein may be designed for a net allowable bearing pressure of 2,500 psf. The allowable soil bearing pressure may be increased by one-third for transient loads, including wind and seismic loads. 3 Spread footings should have a minimum footing width of 18 inches for continuous footings and 24 inches for isolated pads. 4 Based on experience and empirical correlations between soil relative density, compressibility and settlement potential, we estimate total settlement for spread footings designed and constructed as discussed in this section will be approximately 1 inch or less. Differential settlements are estimated to be approximately % to % of the total settlement. 5. Exterior footings and footings beneath unheated areas should be provided with adequate soil cover above their bearing elevation for frost protection. Placement of foundations at least 30 inches below lowest adjacent exterior grade is typically used in this area. 6 The lateral resistance of a spread footing will be a combination of the sliding resistance of the footing on the foundation materials and passive earth pressure against the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated based on a coefficient of friction of 0.30. Passive pressure against the sides of the footings can be calculated using an equivalent fluid density of 180 pcf. The above values are working values with a factor of safety of 2. 7 Compacted fill placed against the sides of the footings to resist lateral loads should meet the material and placement requirements for structural fill in the "Site Grading and Earthwork" section of this report. 8. Granular foundation soils, if used, should be densified with a smooth vibratory compactor prior to placement of concrete. 9 A representative of a qualified geotechnical engineering firm should observe all footing excavations prior to concrete placement. Kumar & Associates, Inc.® 14 Mat/Thickened Slab Foundation: The design and construction criteria presented below should be observed for a mat foundation system. Construction details should be considered when preparing project documents. Mat/thickened slab foundations should be placed on a minimum of 2 feet of structural fill extending to undisturbed native soils. Areas of loose or soft material encountered within the foundation excavation should be removed and replaced with structural fill. 2 Structural fill should meet the material and placement requirements outlined in the "Site Grading and Earthwork" section of this report. Structural fill should extend down and out from the edges of the foundations at a 1 horizontal to 1 vertical projection. A mat/thickened slab foundation supported as recommended above may be designed for an allowable base contact pressure of 2,500 psf. This contact pressure may be increased by one-third for transient loadings other than machine dynamic loads. Higher net allowable base contact pressures may be feasible but should be evaluated based on actual loading conditions. 4 For average sustained loads approaching the allowable base contact pressure, and assuming a rigid mat/thickened slab with symmetrically distributed loads, we estimate total settlements will be on the order of 1 inch or less, depending on the size of the foundation. Post -construction differential settlements between the middle and the edges/corners of a rigid foundation should be negligible for relatively small mats/thickened slabs, but may range up to about one-half of the total settlement for foundations of significant width and length. Non -uniformity of the subsurface conditions and deviation from the rigid foundation assumption will contribute to total and differential settlements. If the foundation cannot be considered rigid, the soil pressure distribution should be computed using a method that models the soil -structure interaction, such as the beam on an elastic foundation procedure. A modulus of vertical subgrade reaction of 125 pci is recommended for the foundation subgrade conditions recommended herein. The provided modulus value should be assumed as uniform under the mat foundation. When the soil pressure distribution has been determined, we should be contacted to evaluate the settlement pattern of the foundation. The process of evaluating the soil Kumar & Associates, Inc.® 15 pressure distribution beneath the foundation may require several iterations for a foundation that classifies between rigid and flexible. The bottom of the mat/thickened slab should be below exterior grade or have turned - down edges extending to depths similar to that described for spread footings. The lateral resistance of a mat/thickened slab foundation placed on structural fill should be calculated using the lateral resistance parameters presented in the "Spread Footings" section of this report. 7 Compacted fill placed against the sides of the foundation to resist lateral loads should meet the material and placement requirements outlined in the "Site Grading and Earthwork" section of this report. 8. Granular foundation soils, if used, should be densified with a smooth vibratory compactor prior to placement of concrete. 9 A representative of a qualified geotechnical engineering firm should observe all mat/thickened slab excavations prior to concrete placement in order to evaluate the supporting capacity of foundation materials. Gravel Pads: We understand gravel pads will be constructed for the support of various lighter equipment. The gravel pads should consist of a minimum of 18 inches of aggregate base course meeting the specifications for CDOT Class 5 of 6 aggregate base course. The gravel pad should be underlain by a minimum of 1 foot of structural fill extending to undisturbed native soils placed as recommended in the "Site -Grading and Earthwork Section" of this report. The gravel pad should be elevated above the surrounding grades as high as feasible to promote positive surface drainage away from the gravel pad foundation. The gravel should be placed in maximum 8 -inch -loose lifts and compacted to at least 95 percent of the modified Proctor (ASTM D1557) maximum dry density at the moisture contents presented in the "Site -Grading and Earthwork Section" of this report. Short Drilled Pier/Footing Foundations: The design and construction criteria presented below should be observed for straight -shaft drilled pier/footing foundations. The construction details should be considered when preparing project documents. Kumar & Associates, Inc.® 16 1 Short drilled piers/footings should extend at least 5 feet below finished grades. 2 For compressive resistance, short drilled piers installed as recommended should be designed for an allowable end bearing pressure of 5,000 psf. The allowable skin friction for short drilled piers in the overburden soils should be considered to be 300 psf. The skin friction in the uppermost 3 feet of the drilled shaft should be ignored. Uplift due to structural loadings on the piers can be resisted by using 75% of the allowable skin friction value plus an allowance for pier weight. 3 The base of the pier/footing excavation should be clean and undisturbed prior to placement of concrete. Based on the results of our field exploration and laboratory testing programs, and our experience with similar, properly constructed short drilled pier/footing foundations, we estimate foundation settlement under the anticipated compressive loads will be less than 1 inch. 5. For ASD calculation of lateral resistance, a modulus of horizontal subgrade reaction of 50 tcf should be used. This method is more suitable for piers with an L/D of less than 10. For piers with an L/D greater than 10, the lateral capacity of the piers may be analyzed using the LPILE computer program and the parameters provided in deep drilled pier section. The criteria provided in the table are for use with that software application only and may not be appropriate for other uses. 6 Site grading should be performed as recommended in the "Surface Drainage" section of this report to reduce the potential for post -construction wetting of the soils supporting the piers. A representative of the geotechnical engineer should observe pier drilling operations on a full-time basis to monitor pier construction procedures, including confirmation that the base of the excavation is clean and undisturbed. Kumar & Associates, Inc.® 17 Deep Drilled Pier: 1 Piers should have a minimum penetration of 6 feet or 3 pier diameters into competent (un-weathered) claystone bedrock, whichever is greater. Piers should also have a minimum length of 30 feet. Both the minimum bedrock penetration and pier length should be achieved. 2 We recommend piers be designed for an allowable skin friction of 1,500 psf for the portion of the piers penetrating into the bedrock. Piers with the recommended minimum bedrock penetration may be designed for an allowable end bearing pressure of 15,000 psf. Uplift due to structural loadings on the piers can be resisted by using 75% of the allowable skin friction value plus an allowance for pier weight. 3 Piers should also be designed for a minimum dead load pressure of 15,000 psf based on pier end area only. Application of dead load pressure is the most effective way to resist foundation movement due to swelling soils and bedrock. However, if the minimum dead load requirement cannot be achieved and the piers are spaced as far apart as practical, the pier length should be extended beyond the minimum bedrock penetration and minimum length to mitigate the dead load deficit. This can be accomplished by assuming one-half of the skin friction value given above acts in the direction to resist uplift caused by swelling soil or bedrock near the top of the pier. The owner should be aware of an increased potential for foundation movement if the recommended minimum deadload pressure is not met. Kumar & Associates, Inc.® 18 4 The lateral capacity of the piers may be analyzed using the LPILE computer program and the parameters provided in the following table. The strength criteria provided in the table are for use with that software application only and may not be appropriate for other usages. The strength criteria provided in the table are for use with this software application only and may not be appropriate for other usages: Material c (psf) o yt ks kc X50 Type Soil Clay Soils 2,000 0 125 500 200 0.007 1 Weathered Claystone 2,000 0 125 500 200 0.007 1 Claystone Bedrock 3,000 0 130 1,000 500 0.005 1 c Cohesion intercept (pounds per square foot) 0 Angle of internal friction (degrees) yt Total unit weight (pounds per cubic foot) ks Initial static modulus of horizontal subgrade reaction (pounds per cubic inch) kc Initial cyclic modulus of horizontal subgrade reaction (pounds per cubic inch) C5o Strain at 50 percent of peak shear strength Soil Types: 1. Stiff Clay (Reese) 5. Closely -spaced piers may require appropriate reductions of the lateral and axial capacities. Reduction in lateral load capacity may be avoided by spacing the piers at least five pier diameters center -to -center in the direction parallel to pier loading. For axial loading, the piers should be spaced a minimum of 3 pier diameters center -to -center. More closely spaced piers should be evaluated on an individual basis to estimate appropriate reductions in axial and lateral load design parameters. If the recommended minimum center -to -center pier spacings for lateral loading cannot be achieved, we recommend the load -displacement curve (p -y curve) for an isolated pier be modified for closely -spaced piers using p -multipliers to reduce all the p values on the curve. With this approach, the computed load carrying capacity of the pier in a group is reduced relative to the isolated pier capacity. The modified p -y curve should then be reentered into the LPILE software to calculate the pier deflection. The reduction in capacity for the leading pier, the pier leading the direction of movement of the group, is less than that for the trailing piers. For loading in the direction parallel to the row of piers, we recommend p -multipliers of 0.8 and 1.0 for pier spacings of 3 and 5 diameters, respectively, for the leading row of piers, 0.4 and 0.85 for pier spacings of 3 and 5 diameters, respectively, for the second Kumar & Associates, Inc.® 19 row of piers, and 0.3 and 0.7 for pier spacings of 3 and 5 diameters, respectively, for the third row and higher. For loading in the direction perpendicular to the row of piers, the p - multipliers are 1.0 for a pier spacing of 5 diameters, 0.8 for a pier spacing of 3 diameters, and 0.5 for a pier spacing of 1 diameter. P -multiplier values for other pier spacing values should be determined by interpolation. These values are consistent with Section 10.7.2.4 of the 2021 AASHTO LRFD Bridge Design Specifications (9th Edition). It will be necessary to determine the load distribution between the piers that attain deflection compatibility because the leading pier carries a higher proportion of the group load and the pier cap prevents differential movement between the piers. 6 Piers should be reinforced their full length to resist an un-factored net tensile force from swelling soil pressure of at least 80 kips. The recommended tensile force is for a 1.5 - foot diameter pier and should be increased in proportion to the pier diameter for larger piers. If the design dead load greater than or less than the recommended dead load, the requirement for tension reinforcement should be decreased or increased accordingly to account for the difference. 7 A minimum 6 -inch void should be provided beneath the grade beams to concentrate pier loadings. Absence of a void space will result in a reduction in dead load pressure, which could result in upward movement of the foundation system. A similar void should also be provided beneath necessary pier cap. 8. Based on the results of our field exploration, laboratory testing, and our experience with similar, properly constructed drilled pier foundations, we estimate pier settlement will be low. Generally, we estimate the settlement of drilled piers will be less than 0.5 -inches when designed according to the criteria presented herein. The settlement of closely spaced piers will be larger and should be studied on an individual basis. 9 A minimum pier diameter of 18 inches is recommended to facilitate proper cleaning and observation of the pier hole. The pier length -to -diameter ratio should not exceed 30. 10. The drilled shaft contractor should mobilize equipment of sufficient size and operating condition to achieve the required penetration in the bedrock. A small diameter pilot hole may be required to advance auger drilling if very hard or cemented bedrock is encountered. Kumar & Associates, Inc.® 20 11. The general lack of water the borings suggests the use of dewatering and casing equipment in the pier holes may not be necessary to control water infiltration. However, if encountered, the requirements for dewatering equipment can sometimes be reduced by placing concrete immediately upon cleaning and observing the pier hole. In no case should concrete be placed in more than 3 inches of water unless placed using an approved tremie method. 12. Care should be taken that the pier shafts are not oversized at the top. Mushroomed pier tops can reduce the effective dead load pressure on the piers. Sono -Tubes or similar forming should be used at the top of the piers, as necessary, to prevent mushrooming of the top of the piers. 13. Pier holes should be properly cleaned prior to the placement of concrete. 14. Concrete used in the piers should be a fluid mix with sufficient slump so it will fill the void between reinforcing steel and the pier hole. We recommend a concrete slump in the range of 5 to 8 inches be used. 15. Concrete should be placed in piers the same day they are drilled. If water is present, concrete should be placed immediately after the pier hole is completed. Failure to place concrete the day of drilling will normally result in a requirement for additional bedrock penetration. 16. A representative of the geotechnical engineer should observe pier drilling operations on a full-time basis to monitor pier construction procedures, including confirmation that the base of the excavation is clean and undisturbed. Helical Piers: The axial design load of helical piers should be determined in general accordance with the current International Building Code (IBC), which states the allowable axial design load, Pa, should be determined as follows: Pa= 0.5 Pu, where Pu (the ultimate load) is the least value of: 1 Sum of the areas of the helical bearing plates times the ultimate bearing capacity of the soil or rock comprising the bearing stratum. Kumar & Associates, Inc.® 21 2. Ultimate capacity determined from well -documented correlations with installation torque. 3. Ultimate capacity determined from load tests. 4. Ultimate capacity of the pier shaft. 5. Ultimate capacity of pier couplings. 6. Sum of the ultimate axial capacity of helical bearing plates affixed to the pier. Items 1 through 3 are related to the geotechnical capacity of the piers; Items 4 through 6 are related to the structural capacity and should be evaluated by the structural engineer. The owner and structural designer should be aware that certain proprietary helical pier systems have been subjected to acceptance testing administered by the International Code Council (ICC), while other systems provided by specialty contractors may be fabricated according to designs by registered professional engineers. The certified systems have documentation that addresses many of the structural capacity issues, while the non -certified systems require structural design by an engineer. Many of the lighter -duty helical pier systems available, with working capacities on the order of 50 kips or less, are certified, which can simplify the design and submittal process. However, higher capacity systems, where single piers may have working capacities of 200 kips or more, sometimes referred to as screw piles, are often designed and fabricated and are not certified manufactured systems. Based on consideration of bearing capacity theory and published correlations of boring penetration resistance values with ultimate bearing capacity, we recommend an ultimate bearing capacity for a helical pier embedded about 2 feet into the bedrock of 25,000 psf, for capacity based on bearing provided by the helices. Helical piers are typically very slender foundation elements with a low capacity for resisting lateral loads. Lateral restraint of a helical pier foundation system is normally provided through the use of passive pressure on pier caps or foundation walls or through the use of battered piers. It is normally assumed that a battered pier can be designed for the same axial load as a vertical pier, with the lateral restraint being provided by the horizontal component of the battered pier. Helical piers are often assumed to have tension capacities similar to the axial compressive capacity, although that should be evaluated through load testing or otherwise addressed by the specialty contractor's submittal. Acceptance of helical pier installation should be based on attaining a specified torque in the recommended bearing stratum determined in accordance with correlations of installation torque Kumar & Associates, Inc.® 22 to capacity based on calibrated torque measurements and axial load test data. In our opinion, the ultimate bearing capacity recommended above may be exceeded if supported by adequate site -specific load test data. If site -specific load tests are not performed, the specialty helical pier contractor's submittal should contain torque -to -capacity data for their pier system in similar soil conditions. If that information cannot be provided, site -specific load tests should be performed in accordance with ASTM D1143. We recommend that a qualified helical pier specialty contractor be retained to provide the required design submittal and to provide and install the helical piers. The project design should include a performance specification indicating required capacities, structural requirements, and submittal requirements. At a minimum, the submittal should be required to contain information supporting the capacity determination, a description of equipment and installation procedures that will ensure penetration to the required depths, and acknowledgment that the helical bearing plates will be installed into the recommended bearing stratum, as well as all necessary information to satisfy the requirements of the project structural designer. We should be retained to review the contractor's submittal and to provide installation observation, including monitoring depths and general conformance with the plans and specifications. Our observation and testing services will be intended to document that all of the helix -bearing plates on the piers are installed into the design -bearing stratum. FOUNDATION DYNAMIC ANALYSIS We anticipate machinery generating dynamic loads will generally be underlain primarily by structural fill and native clay soils underlain by claystone bedrock a depths ranging from about 12.5 to 20 feet. Stabilized groundwater appears to be isolated, if present, and is anticipated to be encountered at depths greater than about 15 feet below the foundations. For dynamic analysis of the foundations, we recommend considering the following soil dynamic properties: Soil Unit Low -Strain Modulus (ksf) Dynamic Shear Poisson's Ratio Damping (%) Ratio Structural Fill / Native Soils 1,500 0.30 2 Claystone Bedrock 2,000 0.35 3 Kumar & Associates, Inc.® 23 The values for the low -strain dynamic shear modulus are estimated based on our experience with sites underlain by similar soils, including shear wave velocity data, and on published correlations for Poisson's ratio and the damping ratio. SLABS -ON -GRADE The native on -site soils, exclusive of topsoil, are suitable to support lightly to moderately loaded slab -on -grade construction. To reduce the effects of some differential movement, floor slabs, if constructed, should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage cracking. Joint spacing is dependent on slab thickness, concrete aggregate size, and slump, and should be consistent with recognized guidelines such as those of the Portland Cement Association (PCA) and American Concrete Institute (ACI). The joint spacing and any requirements for slab reinforcement should be established by the designer based on experience and the intended slab use. If moisture -sensitive floor coverings will be used, additional mitigation of moisture penetration into the slabs such as by use of a vapor retarder, may be required. If an impervious vapor retarder membrane is used, special precautions will be required to prevent differential curing problems which could cause the slabs to warp. This topic is addressed by ACI 302.1 R. Floor slabs should be underlain by a minimum of two feet of structural fill. All fill materials for support of soil -supported slabs should be placed and compacted according to the criteria presented in the "Site Grading and Earthwork" section of this report. The suitability of the on - site soils for use as underslab fill is also discussed in "Site Grading and Earthwork" section. SEISMIC DESIGN CRITERIA The soil profile at the site is anticipated to consist of generally stiff/dense native predominately clay soils with zones of granular soils extending to claystone bedrock at depths ranging from about 9 to 18 feet with the upper few feet of the bedrock being weathered. The bedrock below the weathered zone is antipcated to be firm to hard with isolated very hard zones. The overburden soils classify as International Building Code (IBC) Site Class D and the bedrock will classify as Site Class C based on procedures presented in the code. Based on our general experience on sites with similar types and depths of overburden soils, the design soil profile for the site is considered to be IBC Site Class D. Kumar & Associates, Inc.® 24 Based on the subsurface profile, site seismicity, and the anticipated depth of groundwater, liquefaction is not a design consideration. SLABS ON GRADE Soil -supported slabs should be underlain by a minimum of 2 feet of structural fill meeting the material type and placement recommendations presented in the "Site Grading and Earthwork" section of this report. The native on -site soils, exclusive of any topsoil, are suitable to support lightly to moderately loaded slab -on -grade construction. To reduce the effects of some differential movement, floor slabs, if constructed, should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage cracking. Joint spacing is dependent on slab thickness, concrete aggregate size, and slump, and should be consistent with recognized guidelines such as those of the Portland Cement Association (PCA) and American Concrete Institute (ACI). The joint spacing and any requirements for slab reinforcement should be established by the designer based on experience and the intended slab use. All fill materials for support of soil -supported slabs should be placed and compacted according to the criteria presented in the "Site Grading and Earthwork" section of this report. The suitability of the on -site soils for use as underslab fill is also discussed in "Site Grading and Earthwork" section. LATERAL EARTH PRESSURES Earth retaining structures should be designed for the lateral earth pressure based on the degree of rigidity of the retaining structure and the type of backfill material used. Retaining structures that are fully restrained from lateral movement and can be expected to not deflect should be designed for at -rest earth pressures based on the following equivalent fluid unit densities: Imported CDOT Class 1 Structure Backfill 55 pcf On -site, moisture -conditioned granular soil backfill 60 pcf On -site, moisture -conditioned cohesive soil backfill* 70 pcf *Moisture conditioned clayey soil with swell potential < 0.5% at 200 psf surcharge Kumar & Associates, Inc.® 25 Retaining structures such as loading dock walls that are laterally supported and can be expected to undergo only a moderate amount of deflection should be designed for earth pressures based on the following equivalent fluid unit densities: Imported CDOT Class 1 Structure Backfill 50 pcf On -site, moisture -conditioned granular soil backfill 55 pcf On -site, moisture -conditioned cohesive soil backfill* 65 pcf * Moisture conditioned clayey soil with swell potential < 0.5% at 200 psf surcharge Cantilevered retaining structures that can be expected to deflect sufficiently to mobilize the full active earth pressure condition should be designed for the following equivalent fluid unit densities: Imported CDOT Class 1 Structure Backfill 40 pcf On -site, moisture -conditioned granular soil backfill 55 pcf On -site, moisture -conditioned cohesive soil backfill* 45 pcf * Moisture conditioned clayey soil with swell potential < 0.5% at 200 psf surcharge The equivalent fluid densities recommended above assume drained conditions behind the wall or retaining structures and a horizontal backfill surface. The buildup of water behind a wall or retaining structure, or an upward sloping backfill surface, will increase the lateral pressure imposed on the wall or retaining structure. Care should be taken not to over compact the backfill since this could cause excessive lateral pressure on the structure. Hand compaction procedures, if necessary, should be used to prevent lateral pressures from exceeding the design values. We recommend calculating design lateral pressures due to surcharge loads using a lateral earth pressure coefficient of 0.6. For passive lateral earth pressures, we recommend the following allowable equivalent fluid unit densities: Imported CDOT Class 1 Structure Backfill 220 pcf On -site, moisture -conditioned granular soil backfill 185 pcf On -site, moisture -conditioned cohesive soil backfill* 170 pcf * Moisture conditioned clayey soil with swell potential < 0.5% at 200 psf surcharge Kumar & Associates, Inc.® 26 SURFACE DRAINAGE Proper surface drainage is very important for acceptable performance of site structures and other facilities during construction and after the construction has been completed. Drainage recommendations provided by local, state and national entities should be followed based on the intended use of each structure. The following recommendations should be used as guidelines and changes should be made only after consultation with the geotechnical engineer. 1 Excessive wetting or drying of the foundation and slab subgrades should be avoided during construction. The ground surface surrounding the exterior of site structures and facilities should be sloped to drain away from the foundations in all directions. We recommend a minimum slope of 6 inches in the first 10 feet. Site drainage beyond the 10 -foot zone should be designed to promote runoff and reduce infiltration. The slopes may be changed as required for handicap access points in accordance with the Americans with Disabilities Act. 3 Exterior backfill should meet the material and placement requirements outlined in the "Site Grading and Earthwork" section of this report. The upper 2 feet of backfill adjacent to site structures and facilities should be relatively impervious compacted material to promote runoff and limit infiltration of surface water. 4 Ponding of water should not be allowed in backfill material or in a zone within 10 feet of site structures and facilities, whichever is greater. WATER-SOLUBLE SULFATES Concentrations of water-soluble sulfates measured in two samples of the native overburden soils ranged from 0.01 % to 0.22%. These concentrations represent a Class SO to S2 severity exposure to sulfate attack on concrete exposed to these materials. The concentration of water- soluble sulfates measured in a representative sample of the claystone bedrock obtained from the borings was 0.19%. This concentration represents a Class S1 severity exposure to sulfate attack on concrete exposed to the bedrock materials. The degree of attack is based on a range of Class SO (not applicable), Class S1 (moderate), Class S2 (severe), and Class S3 (very severe) severity of exposure as presented in ACI 201.2R. Kumar & Associates, Inc.® 27 Based on the laboratory data and our experience, we recommend all concrete exposed to the on -site overburden soils and bedrock should meet the requirements for resistance to a Class S2 severity exposure as presented in ACI 201.2R. Alternatively, the concrete could meet the Colorado Department of Transportation's (CDOT) cement requirements for Class 2 exposure as presented in Section 601.04 of the CDOT Standard Specifications for Road and Bridge Construction (2021). FIELD THERMAL RESISTIVITY TESTING Field and laboratory thermal resistivity testing was performed for the project. The field thermal resistivity testing was performed at the three locations shown on Fig. 1. The testing was conducted at depths of about 24 and 48 inches as requested by Mountain Peak Power, LLC. The results of the field thermal resistivity testing area summarized in the table below: Location Test Depth (in) Heat Conduction ( W/m*°K ) Resistivity (m*°K/w) Thermal Temperature (°C) 1 24 1.519 0.658 18.4 1 48 1.325 0.754 7.7 2 24 1.031 0.969 7.6 2 48 1.520 0.657 15.5 3 24 1.447 0.690 11.4 3 48 1.493 0.669 9.2 °K = Degrees Kelvin, W = Watts, m = meter, °C = Degrees Celsius Laboratory testing consisting of thermal resistivity, pH, and concentration of chlorides is currently being performed on 3 composite bulk samples of soils obtained in the upper 4 feet at the three locations of the field thermal resistivity testing, as shown on Fig. 1. Thermal dryout curves along with measure gravimetric water content and measured resistivity (Rho) used to generate the curves will be provided in the final report. The electrical resistivity testing is being performed in general accordance with the applicable IEEE standard test procedure. ELECTRICAL RESISTIVITY AND BURIED METAL CORROSION The potential for corrosion of buried metals or metal pipes placed beneath the ground surface at the site was evaluated based on the results of both laboratory tests performed on representative bulk samples of the native overburden soils and filed electrical resistivity testing performed at the site. The bulk samples selected for laboratory testing were tested to evaluate electrical resistivity, pH, and chloride concentration. The electrical resistivity was performed in general accordance with the applicable IEEE standard test procedure. Kumar & Associates, Inc.® 28 The results of the laboratory electrical resistivity testing performed on two representative samples of the native clay soils indicated minimum laboratory electrical resistivity values of 470 and 726 ohm -cm. Corresponding resistivity values of about 575 om-cm was measured at the optimum moisture content and 920 ohm -cm were measured at the in -situ moisture content of 17.0%, respectively. Based on the laboratory resistivity test results, the native overburden soils would generally be classified as very corrosive at moistures generally greater than about 12% to 15% and generally moderately corrosive at lower moisture contests as presented by the U.S. Bureau of Reclamation and the National Association of Corrosion Engineers. The results of the laboratory electrical resistivity testing are presented on Fig. 22. Field electrical resistivity testing was also performed at the three approximate locations indicated on Fig. 1. The electrical resistivity of the near -surface soils at each site was measured in the field using the Wenner Four -Electrode method on December 11, 2023. The testing was completed at spacing intervals of about 2.5-, 5-, 10-, 15-, 20-, 30- and 40 -feet, along two lines in opposite directions. One line was generally oriented in the north -south direction and the other line was generally oriented in the east -west direction. The calculated results of the field electrical resistivity testing are summarized in the following table. Resistivity curves plotting the measured electrical resistivity (ohm -m) versus the probe spacing (m) are presented on Figs. 19 through 21. Field Resistivity Testing Results Test Location Spacing Probe (ft.) Calculated Electrical Resistivity (ohm -cm) Line 1 (North -South) Line 2 (East-West) East-West ERT 1B 1A & 2.5 2,542 3,485 5 1,187 1,561 10 804 843 15 833 919 20 651 728 30 632 575 40 536 613 ERT 2B 2A & 2.5 8,857 12,927 5 2,490 3,591 10 1,379 1,302 15 1,465 1,465 20 881 1,034 30 977 1,034 40 843 919 ERT 3B 3A & 2.5 8,139 5,267 5 4,931 3,782 10 1,685 1,570 15 1,034 1,207 20 919 804 30 1,034 919 40 689 843 ERT: Electrical Resistivity Test Kumar & Associates, Inc.® 29 The results of the field resistivity testing for the project indicate the on -site overburden soils would generally be classified as very to moderately corrosive in accordance with a classification system published by the U.S. Bureau of Reclamation and the National Association of Corrosion Engineers. The results of the field electrical resistivity testing are very similar to the laboratory electrical resistivity testing results presented above. Based on laboratory test results, the in -situ moisture contents of the native granular soils was 1.9%, 1.9%, and 11.1%. The moisture content measured in the native clay samples ranged from about 7% to 19%. The moisture content measured in samples of the claystone bedrock were 16.5% and 24%. The native granular soils are expected to exhibit good to fair drainage characteristics and the native clay soils and bedrock will likely exhibit poor drainage characteristics. Corrosion of buried metal is a complex process and requires an understanding of the combined effects of ion content, electrical resistivity, soil moisture, which were evaluated as part of this study and various other conditions not evaluated as part of this study. We recommend a qualified corrosion engineer review the information presented herein to determine the need for an appropriate level of corrosion protection for buried metals at the site. AGGREGATE -SURFACED ROADWAYS AND YARD AREAS Subgrade Materials: Based on the results of the field exploration and laboratory testing programs, the subgrade materials underlying aggregate -surfaced areas are anticipated to consist primarily of the native clay soils with lenses and zones of native granular soils, and to primarily classify as A-6 and A-7-6 soils with group index values ranging from 4 to 22 in accordance with the American Association of State Highway and Transportation Officials (AASHTO) soil classification system. Three samples classified as an A -1-a, A-3, and A-4 soil with a group index value of 0. Soils classifying as A -1-a would generally be considered to provide excellent subgrade support. Soils classifying as A-3 and A-4 would generally be considered to provide fair subgrade support, and soil classifying as A-6 or A-7-6 would generally be considered to provide poor subgrade support. To further evaluate the subgrade soil's ability to support aggregate -surfacing pavements and associated traffic, an Hveem-stabilometer (R -value) was performed on a composite bulk sample of the native overburden clay soils. The results of the R -value testing indicated an R -value of Kumar & Associates, Inc.® 30 less than 5 at an exudation pressure of 300 psi. Using the CDOT correlation table, a subgrade resilient modulus of 3,000 psi Design Traffic: In general, traffic over most of the site roadways and yard areas is expected to consist of a relatively low volume of light- to medium- weight trucks, and occasional heavy- weight trucks. Aggregate -Surface Thicknesses: Based on our experience, a thickness of 10 inches should be considered for aggregate surfacing for unpaved roadways and other areas accessed by vehicles. Greater thicknesses should be used in turn -around areas and areas that may be used routinely by heavier vehicles. A thickness greater than 12 inches may be preferred for any heavily used access driveways. We recommend aggregate surfacing consist of a CDOT Class 5 or 6 Aggregate Base Course (ABC) material. For ease of maintenance, particularly for high traffic site roadways, the upper 6 inches of the aggregate surfacing should consist of a CDOT Class 6 ABC material preferably containing some clay fines. For high -traffic site roadways subject to a significant number of heavier vehicles, the aggregate surfacing should be underlain by at least 12 inches of granular sub -base material consisting of compacted granular fill consistent with a material classifying as A-6 or better. The owner may have other preferences for construction of unpaved on -site roadways and other vehicle areas based on their experience. Subgrade Preparation: Prior to placing the aggregate surfacing, the entire subgrade area should be scarified to a depth of 12 inches, adjusted to a moisture content near optimum and compacted to at least 95% of the standard Proctor (ASTM D698) maximum dry density. Structural fill placed beneath the aggregate -surfacing should be placed and compacted as recommended in the "Site Grading and Earthwork" section of this report. Prepared subgrades for aggregate surfacing should be proofrolled with a heavily loaded pneumatic -tired vehicle. Areas that deform excessively under heavy wheel loads are not considered stable and should be removed and replaced to achieve a stable subgrade prior to placement of the aggregate surfacing, including the sub -base layer where recommended. Kumar & Associates, Inc.® 31 The collection and diversion of surface drainage away from roadway and yard areas is extremely important to the satisfactory performance of the aggregate surfacing. DESIGN AND CONSTRUCTION SUPPORT SERVICES K+A should be retained to review the project plans and specifications for conformance with the recommendations provided in our report. We are also available to assist the design team in preparing specifications for geotechnical aspects of the project, and performing additional studies, if necessary, to accommodate possible changes in the proposed construction. We recommend K+A. be retained to provide construction observation and testing services to document the intent of this report and the requirements of the plans and specifications are being followed during construction. This will allow us to identify possible variations in subsurface conditions from those encountered during this study and to allow us to re-evaluate our recommendations, if needed. We will not be responsible for implementation of the recommendations presented in this report by others, if we are not retained to provide construction observation and testing services LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering practices in this area for exclusive use by the client for design purposes. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings at the locations indicated on Fig. 1, and the proposed type of construction. This report may not reflect subsurface variations that occur between or beyond the exploratory borings, and the nature and extent of variations across the site may not become evident until site grading and excavations are performed. If during construction, fill, soil, rock or water conditions appear to be different from those described herein, K+A should be advised at once so a re-evaluation of the recommendations presented in this report can be made. K+A is not responsible for liability associated with interpretation of subsurface data by others. Swelling bedrock is present on this site. Such bedrock materials are stable at their natural moisture content but will undergo high volume changes with changes in moisture content. The extent and amount of perched water beneath the site as a result of area irrigation and inadequate surface drainage is difficult, if not impossible, to foresee. Kumar & Associates, Inc.® 32 The recommendations presented in this report are based on current theories and experience of our engineers on the behavior of bedrock materials in this area. The owner should be aware there is a risk in constructing in an expansive bedrock area. Following the recommendations given by a geotechnical engineer, careful construction practice and prudent maintenance by the owner can, however, decrease the risk of foundation, floor slab, and pavement movement due to expansive bedrock. JDC/mm Rev: JLB cc: File Kumar & Associates, Inc.® a 3 0 I 0 M N al C t a a 0 0 0 a a N 0 0 a v d C a C 0 E� 0 M u? O N N I O I N V ✓ N N N O N a O U 7 0_ 0 AMMONI Latigitlatelei9'ti] UNLOADING THERMAL 1 GSILI-1 —! .1 Vial RETENTION POND 14.14NII•l*9/III4tSYL111 j FIRE PUMP ENCLOSUR BORING 1 CONTROL ROOM ILOCKER "OOMS BUILDING AIR COMPRESSORS UG UTILITY AND EQUIPMENT ACCESS AREA BORING 5 FUTURE 4JNITED POWER BATTERY STORAGE Is PROJECT AREA BH#2 — GSUl-3 1E BORING 2 ERT LOC:AIION #'2A Y #B — GROUNDING. TRANSFORMER (TY'P). NV DI;; ONNL CT AND CABLE F`.'I SER.;TYPi PLANT ACCESS ROAD �rI1 \ 1 assig lgolalms - R.9 FUTURE SECTIONAIJIZING BREAKER AND DISCONNECTS (TYP® EXISTING SOUTH -BOUND 69 kV T -LINE COUNTY ROAD 22 71J��H�FY X.]ia lIL.]►II►Lc BORING 8 G U GSU-5 c.SU 6 SWITCHYARD BAY COMPRISED OF CABLE RISER. DISCONNECTS AND CIRCUIT BREAKER (TYP) EXISTING NORTH4 BOUND 69 kV T - LINE EXPANDED EXISTING SUBSTATION (69 kV/13.2k 422'-0" X 1331-6'1X APPROX 60' 0" h MAXIMUM TAKE -OFF STRUCTURE (TYP) EXISTING PUMP HOUSE r- EXISTING WELL NEW CONTROL BUILDING AS REO'D EXISTING SUBSTATION GQIyTRQL BUILDING 0 METER YARD HAZARDOUS AREA (TYP) 5 - UNITED POWER SEMENT UNITED POWER SEMENT THERMAL 3 30' DRAJ EASEMENT 4 1 23-1-750 Kumar & Associates MOUNTAIN PEAK POWER STATION, WELD COUNTY/KEENESBURG, COLORADO LEGEND: 50 0 50 100 APPROXIMATE SCALE -FEET A FIELD THERMAL RESISTIVITY TESTING LOCATION. FIELD ELECTRICAL RESISTIVITY TESTING LOCATION. • BORING LOCATION. . TEST PIT LOCATION. r I ei 4 lr_ wl SITE 1 VICINITY MAP NOT TO SCALE 1 Ccr Q� to LOCATION OF EXPLORATORY BORINGS Fig. 1 BORING 1 BORING 2 BORING 3 BORING 4 BORING 5 BORING 6 BORING 7 BORING 8 TEST PIT 1 EL. 4954.8' EL. 4958' EL. 4963' EL. 4963.8' EL. 4956' EL. 4963' EL. 4956.4' EL. 4960.5' EL. 4952.2' 20/12 4965 -200=81 LL=44 WC=12.5 15/12 4965 DD=114.9 WC=8.7 P1=28 N -200=54 DD=95.0 WSS=0.22 LL=26 26/12 -200=62 RES=470 12/12 PI=13 13/12 WC=17.1 LL=28 R<5 10/12 A-6 (4) WC=19.6 DD=97.8 PI=12 A-7-6 (22) 16/12 DD=102.0 -200=84 A-6 (5) 33/12 0 0MC=17.9 16/12 8/12 4960 -200=74 LL=31 4960 WC=7.6 =92.9 MDD=104.7 LL=39 PI=16 11/12 01 P1=23 A-6 (12) -200=75 7/12 12/12 0°13/12 LL=31 WC=1.9 14/12 P1=15 / 14/12 DD=103.0 A-6 (9) -200=10 N / NV 12/12 8/12 15/12 4955 4955 NP 31 /1 2 / A-1 -a (0) / 20/12 / // 26/12 014 12 :f 21/12 WC=18.5 // / 10/12 15/12 / DD=109.0 / I / =200=92 / / / 11/12 / / L=35 17/12 - WC=1 .9 / 21/12 / P1=17 +4=0 4950 4950 / / 200=9 / / 1 2/1 2 27/1 2 /• N V ::• / / 22/12 14/12 WC=20.4 / 28/12 // NP / 21/12 DD=107.0 / WC=19.2 A-3 / (0) -200=97 : / / DD=107.2 / 8/1 2 / -200-92 LL=50 / 22/12 1 4/12 / / / 25/12 LL=33 P1=29 / / / / / 12/12 P1=14 / 36/12 // 4945 4945 / / 33/12 / / WC=23.8 / w ,w / / z / 16/12 / / DD=99.6 / / -200=88 -200=60/ z o / WC=119.9 LL=23 / DD=107.7 / LL=80 / 27/12 P1=54 35/12 P1=7 LVA 'A / / / WSS=O.19 38/12 ,1, d.0 / 8 / —j / 13/12 = / UC=47.8 4940 4940 // 24/12 / / / / 30/12 26/12 / 48/12 32/12 37/12 48/12 17/12 4935 4935 33/12 40/12 50/10 50/4 33/12 32/12 45/12 50/9 WC=17.0 WC=16.6 4930 DD=111.2 4930 —200=97 14/12 21 12 DD=114.9 —200=96 LL 50/4 WC=17.0 7.0 DD=107.1 07.1 WC=1 3.5 DD=1 1 2.2 LL=53 P1=38 -200=85 -200=82 P1=34 UC=1 38 UC=84.4 LL=30 P1=14 50/11 LL=31 P1=15 48/12 50/11 24/12 WSS=0.01 A-6 (11) 4925 WC=6.7 RES=726 4925 DD=116.1 A-6 (10) 12/12 -200=63 WC=11.1 1 .1 LL=25 P1=1 0 DD=94.8 -200=40 A-4 (4) LL=19 9 P1=5 4920 4920 23-1-750 Kumar & Associates MOUNTAIN PEAK POWER STATION, WELD COUNTY/KEENESBURG, COLORADO LOGS OF EXPLORATORY BORINGS Fig. 2 LEGEND I TOPSOIL. LEAN CLAY (CL) WITH VARIABLE FINE- TO MEDIUM -GRAINED SAND CONTENT, STIFF TO VERY STIFF WITH ISOLATED MEDIUM AND HARD ZONES, SLIGHTLY MOIST TO MOIST, TAN TO BROWN. POORLY -GRADED SAND WITH SILT (SP-SM) TO SILTY CLAYEY SAND (SC-SM), FINE- TO MEDIUM -GRAINED, MEDIUM DENSE, SLIGHTLY MOIST, ISOLATED ORGANICS IN NEAR SURFACE SOILS, TAN TO BROWN. WEATHERED CLAYSTONE, FINE-GRAINED SAND FRACTION, MOIST, BROWN TO GRAY -BROWN. CLAYSTONE BEDROCK, FINE-GRAINED SAND FRACTION, LOW TO HIGH PLASTICITY, FIRM TO HARD WITH ISOLATED VERY HARD ZONES, ISOLATED SILTY ZONES, MOIST, GRAY TO GRAY -BROWN TO DARK GRAY WITH OCCASIONAL IRON OXIDATION STAINING AND FREQUENT LIGNITE INCLUSIONS. DRIVE SAMPLE, 2 -INCH I.D. CALIFORNIA LINER SAMPLE. DISTURBED BULK SAMPLE. 26/12 DRIVE SAMPLE BLOW COUNT. INDICATES THAT 26 BLOWS OF A 140 -POUND HAMMER FALLING 30 INCHES WERE REQUIRED TO DRIVE THE SAMPLER 12 INCHES. 8 DEPTH TO WATER LEVEL AND NUMBER OF DAYS AFTER DRILLING MEASUREMENT WAS MADE. NOTES 1. THE EXPLORATORY BORINGS WERE DRILLED ON DECEMBER 12, 2023 WITH A 4 -INCH -DIAMETER CONTINUOUS -FLIGHT POWER AUGER. THE TEST PIT WAS EXCAVATED WITH A MINI -EXCAVATOR O N DECEMBER 1 1 , 2023. 2. THE LOCATIONS OF THE EXPLORATORY BORINGS WERE MEASURED APPROXIMATELY BY HANDHELD GPS DEVICE. 3. THE ELEVATIONS OF THE EXPLORATORY BORINGS WERE MEASURED BY ROD & LEVEL AND THE LOGS OF THE EXPLORATORY BORINGS ARE PLOTTED TO DEPTH. 4. THE EXPLORATORY BORING LOCATIONS AND ELEVATIONS SHOULD BE CONSIDERED ACCURATE O NLY TO THE DEGREE IMPLIED BY THE METHOD USED. 5. THE LINES BETWEEN MATERIALS SHOWN ON THE EXPLORATORY BORING LOGS REPRESENT THE APPROXIMATE BOUNDARIES BETWEEN MATERIAL TYPES AND THE TRANSITIONS MAY BE GRADUAL. 6. GROUNDWATER WAS NOT ENCOUNTERED IN THE BORINGS AT THE TIME OF DRILLING OR WHEN CHECKED 8 DAYS LATER. 7. LABORATORY TEST RESULTS: WC = WATER CONTENT (%) (ASTM D2216); DD = DRY DENSITY (pcf) (ASTM D2216); +4 = PERCENTAGE RETAINED ON NO. 4 SIEVE (ASTM D6913); -200= PERCENTAGE PASSING NO. 200 SIEVE (ASTM D1140); LL = LIQUID LIMIT (ASTM D4318); PI = PLASTICITY INDEX (ASTM D4318); NV = NO LIQUID LIMIT VALUE (ASTM D4318); NP = NON -PLASTIC (ASTM D4318); WSS = WATER SOLUBLE SULFATES (%) (CP-L 2103); RES = MINIMUM LABORATORY RESISTIVITY (ohm —cm.) (ASTM G 57); R = HVEEM R -VALUE (AT 300 psi) (ASTM D2844); UC = UNCONFINED COMPRESSIVE STRENGTH (psi) (ASTM D 2166); O MC = OPTIMUM MOISTURE CONTENT (%) (ASTM D698); MDD = MAXIMUM DRY DENSITY (pcf) (ASTM D698); A-6 (9) = AASHTO CLASSIFICATION (GROUP INDEX) (AASHTO M 145). 23-1 —750 1 Kumar & Associates IMOUNTAIN PEAK POWER STATION, WELD COUNTY/KEENESBURG, COLORADO LEGEND AND EXPLANATORY NOTES Fig. 3 0' 0 0 4- 0 I Q vI N ;re.; N C 4- C 0 0 0 4- L m 0 a a m a c 0 4- c ▪ 0 to in O h I O " I I M N N Oil 0 et y O t U 3 • d O > (%) 1-13MS - NOIJ YGI1OSNOD SAMPLE FROM: WC —200 = OF: Boring 7.6 %, = 75 Lean 1 %, DD LL Clay © = 2.5' 104.7 = 31 with , PI Sand pcf = 15 (CL) .1 NO MOVEMENT WETTING UPON These test results apply only to the samples tested. The testing report shall not be reproduced, except in full, without the written approval of Kumar and Associates, Inc. Swell Consolidation testing performed in accordance with ASTM D-4546. 1.0 APPLIED PRESSURE - KSF 10 100 23-1-750 Kumar & Associates SWELL —CONSOLIDATION TEST RESULT Fig. 4 0' 0 0 4- 0 I Q vI N ;re.; N C 4- C 0 0 0 4- L m 0 a a m a c 0 4- c ▪ 0 to in O h I O " I I M N N Oil 0 et y O t U 3 • d O > 4 3 .1 SAMPLE FROM: WC —200 = Boring 17.0 = OF: Claystone %, 97 %, 1 DD LL @ 24' = = 111.2 56, Bedrock PI pcf = 38 H EXPANSION PRESSURE UNDER UPON CONSTANT WETTING J M I These test results apply only to the samples tested. The testing report shall not be reproduced, except in full, without the written approval of Kumar and Associates, Inc. Swell Consolidation testing performed in accordance with ASTM D-4546. 1.0 APPLIED PRESSURE - KSF 10 100 23-1-750 Kumar & Associates SWELL —CONSOLIDATION TEST RESULT Fig. 5 SAMPLE FROM: OF: Boring Lean Clay 4 @ with 7.5' Sand (CL) WC = 19.6 —200 = %, 74 %, DD LL = 102.0 = 39, PI pcf = 23 0 1 ADDITIONAL COMPRESSION UNDER CONSTANT PRESSURE DUE TO WETTING CONSOLIDAI a w ry .1 1.0 APPLIED PRESSURE - KSF 10 100 SAMPLE FROM: Boring OF: Claystone 4 @ 14' Bedrock WC —200 = 20.4 = 97 %, %, DD LL = 107.0 = 50, PI p = cf 29 0 1 EXPANSION UNDER CONSTANT J J LA PRESSURE UPON WETTING z • O I. -, CONSOLIDAI I I CA N These test results apply only to the samples tested. The testing report shall not be reproduced, except in full, without the written approval of Kumar and Associates, Inc. Swell Consolidation testing performed in accordance with ASTM D-4546. .1 1.0 APPLIED PRESSURE - KSF 10 100 23-1-750 Kumar & Associates SWELL -CONSOLIDATION TEST RESULTS Fig. 6 0' 0 0 4- 0 I Q vI N ;re.; N C 4- C 0 0 0 4- L m 0 a a m a c 0 4- c ▪ 0 to in O h I O " I I M N N Oil 0 et y O t U 3 • d O > DATION - SWELL (%) 1 .1 SAMPLE FROM: WC —200 = Boring 13.5 = OF: 82 Lean 5 %, %, DD LL Clay © 5' = 112.2 = 31, with PI Sand pcf = 15 (CL) UNDER ADDITIONAL DUE CONSTANT TO COMPRESSION WETTING PRESSURE J -4 J 0 z 0 o These test results apply only to the samples tested. The testing report shall not be reproduced, except in full, without the written approval of Kumar and Associates, Inc. Swell Consolidation testing performed in accordance with ASTM D-4546. 1.0 APPLIED PRESSURE - KSF 10 100 23-1-750 Kumar & Associates SWELL —CONSOLIDATION TEST RESULT Fig. 7 04 0 0 4- 0 vI N ;re.; N C 4- C 0 0 0 4- L m 0 a 0 m a c 0 4- c .�Q o r, I O " I I M N N 0 et y O t U 3a 0 > co in K] CV 0 I c (%) 1-13MS - NOIJ YGI1OSNOD .1 SAMPLE FROM: WC —200 = OF: Claystone Boring 23.8 %, = 88 %, 6 DD LL @ 19' = = 99.6 80, Bedrock PI pcf = 54 I EXPANSION PRESSURE UNDER UPON CONSTANT WETTING These test results apply only to the samples tested. The testing report shall not be reproduced, except in full, without the written approval of Kumar and Associates, Inc. Swell Consolidation testing performed in accordance with ASTM D-4546. 1.0 APPLIED PRESSURE - KSF 10 100 23-1-750 Kumar & Associates SWELL —CONSOLIDATION TEST RESULT Fig. 8 04 0 0 4- 0 vI N ;re.; N C 4- C 0 0 0 4- L m 0 a 0 m a c 0 4- c .�Q o r, I O " I I M N N 0 et y O t U 3a 0 > 2 0 .1 SAMPLE FROM: WC —200 = Boring 11.1 = OF: 40 Silty %, %, 7 DD LL Clayey © 7.5' = = 19, Sand 94.8 PI pcf = (SC-SM) 5 - UNDER ADDITIONAL DUE CONSTANT TO COMPRESSION WETTING PRESSURE u I I (%) T13MS - NOIJYGIlOSNOD J These test results apply only to the samples tested. The testing report shall not be reproduced, except in full, without the written approval of Kumar and Associates, Inc. Swell Consolidation testing performed in accordance with ASTM D-4546. 1.0 APPLIED PRESSURE - KSF 10 100 23-1-750 Kumar & Associates SWELL —CONSOLIDATION TEST RESULT Fig. 9 3 0 O Ln N a C 0 O L O C O v V) C O O d 0 C 0 0 C O O 7 O O v i on IC I O I N N N N • h O t- 0 • a c a▪ > HYDROMETER ANALYSIS SIEVE ANALYSIS 100 TIME READINGS 24 HRS 7 HRS 45 MIN 15 MIN 60MIN 19MIN 4MIN 1MIN #200 U.S. STANDARD SERIES #100 #50 #40 #30 ; _16 1410 #8 #4 CLEAR SQUARE OPENINGS 3/8" 3 4" 1 1L2" 3" 5"6" 8"0 I I 90 10 20 80 H 70 I- I � I � ! I PERCENT PASSING d o 0 0 0 0 0 I I I 0 00 00 0 00 CA 0 0 0 PERCENT RETAINED L I I I I I I I I I - 1 I I I I I I I I 1 I I I I I I I I I I I I I I-i 1. 1 7 TI I r I r iZ I I 1 1 1-1 1 1 T1 I I- 1-i-1 1-1 ri 1 .001 .002 .005 .009 .019 .037 .075 DIAMETER .150 .300 .600 1.18 .425 OF PARTICLES IN MILLIMETERS 2.0 2.36 4.75 9.5 19 38.1 76.2 127 152 200 CLAY TO SILT SAND GRAVEL COBBLES FINE MEDIUM COARSE FINE COARSE GRAVEL SAMPLE 0 LIQUID LIMIT OF: Poorly % —Graded NV SAND 91 % PLASTICITY Sand with Silt (SP-SM) INDEX NP SILT FROM: AND CLAY Test Pit 1 9 © 4' These test results apply only to the samples which were tested. The testing report shall not be reproduced, except in full, without the written approval of Kumar & Associates, Inc. Sieve analysis testing is performed in accordance with ASTM D6913, ASTM D7928, ASTM C136 and/or ASTM D1140. 23-1-750 Kumar & Associates GRADATION TEST RESULTS Fig. 10 g\231750-11 to 14.dwg COMPACTION TEST REPORT Curve No. 3186 94.5 ZAV SpG Preparation Method 2.60 17.9%, 92.9 pcf I Rammer: Wt. 5.5 lb. Drop 12 in. Type Manual Layers: No. 3 Blows per 25 Mold Size 0.03333 cu. ft. Test Performed on Material Passing #4 Sieve Dry density, OO OO OO cn o %>#4 0 %<No.200 81 Atterberg (D 4318): LL 44 PI 28 NM (D 2216) Sp.G. (D 854) 2.6 uscs (D 2487) CL AASHTO (M 145) Date: Sampled 12/13/23 Received 12/13/23 13.5 15 16.5 18 19.5 21 22.5 Tested 12/14/23 Tested By AS Water COMPACTION ASTM D 698-12 content, Method TESTING DATA A Standard SIEVE TEST RESULTS 1 2 3 4 5 6 Opening Size % Passing Specs. WM + WS 6172.0 6266.0 6297.0 6249.0 WM 4635.0 4635.0 4635.0 4635.0 WW + T #1 614.4 633.6 631.9 726.9 WD + T #1 555.0 564.4 554.9 626.3 TARE #1 154.1 152.1 153.7 149.8 WW+T#2 WD+T#2 TARE #2 MOIST. 14.8 16.8 19.2 21.1 DRY DENS. 88.4 92.2 92.0 88.0 TEST RESULTS Material Description Maximum Optimum dry moisture density = 17.9 = 92.9 pcf Lean Clay with Sand (CL) Remarks: These were tested. reproduced, approval Moisture/density accordance performed analysis D1140. test results apply only to the samples which the testing report shall not be except in full, without the written of Kumar and Associates, Inc. relationships performed in with ASTM D698, D1557. Atterberg limits in accordance with ASTM D4318 sieve performed in accordance with ASTM D422, Project No. 23—1-750 Client: Project: Mountain Peak Power O Location: Boring B2 Depth: 1'-5' Sample Number: 3186 Checked by: JJM Title: Lab Manager 23-1-750 Kumar & Associates MOISTURE —DENSITY RELATIONSHIPS Fig. 11 g\231750-11 to 14.dwg COMPACTION TEST REPORT Curve No. 3206 114 11.3%, 113.1 pcf ZAV SpG Preparation Method 2.60 Rammer: Wt. 5.5 lb. Drop 12 in. 112.5 Type Manual Layers: No. 3 Blows per 25 Mold Size 0.03333 cu. ft. 111 U d Test Performed on Material Passing #4 Sieve %>#4 0 %<No.200 16 109.5 o Atterberg (D 4318): LL NV PI NP NM (D 2216) Sp.G. (D 854) 2.6 uscs (D 2487) SM 108 AASHTO (M 145) Date: Sampled 12/26/23 Received 12/26/23 106.5 4 6 8 10 12 14 16 Tested 12/26/23 Tested By AS Water COMPACTION ASTM D 698-12 content, TESTING Method DATA A Standard SIEVE TEST RESULTS 1 2 3 4 5 6 Opening Size % Passing Specs. WM + WS 6124.0 6204.0 6271.0 6268.0 WM 4365.0 4365.0 4365.0 4365.0 WW + T #1 513.8 622.2 512.8 366.8 WD + T #1 495.6 594.8 483.1 336.2 TARE #1 233.3 302.3 218.8 108.1 WW+T#2 WD+T#2 TARE #2 MOIST. 6.9 9.4 11.2 13.4 DRY DENS. 108.6 111.0 113.1 110.8 TEST RESULTS Material Description Maximum Optimum dry moisture density = 11.3 = 113.1 pcf Silty Sand Remarks: These were tested. reproduced, approval Moisture/density accordance performed analysis D1140. test results apply only to the samples which the testing report shall not be except in full, without the written of Kumar and Associates, Inc. relationships performed in with ASTM D698, D1557. Atterberg limits in accordance with ASTM D4318 sieve performed in accordance with ASTM D422, Project No. 23—1-750 Client: Project: Mountain Peak Power O Location: TRT #1 Depth: 1'-5' Sample Number: 3206 Checked by: JJM Title: Lab Manager 23-1-750 Kumar & Associates MOISTURE —DENSITY RELATIONSHIPS Fig. 12 g\231750-11 to 14.dwg COMPACTION TEST REPORT Curve No. 3207 115 ZAV SpG 2.60 Preparation Method 12.5%, 113.0 pcf Rammer: Wt. 5.5 lb. Drop 12 in. Type Manual Layers: No. 3 Blows per 25 Mold Size 0.03333 cu. ft. Test Performed on Material Passing #4 Sieve %>#4 0 %<No.200 23 ) ry d Atterberg (D 4318): LL 19 PI 4 NM (D 2216) Sp.G. (D 854) 2.6 uscs (D 2487) SC-SM AASHTO (M 145) Date: Sampled 12/26/23 Received 12/26/23 Tested 12/26/23 7.5 9 10.5 12 13.5 15 16.5 Tested By AS Water COMPACTION ASTM D content, 698-12 TESTING Method DATA A Standard SIEVE TEST RESULTS 1 2 3 4 5 6 Opening Size % Passing Specs. WM + WS 6154.0 6230.0 6295.0 6243.0 WM 4365.0 4365.0 4365.0 4365.0 WW + T #1 436.1 471.8 487.6 552.3 WD + T #1 413.2 447.4 453.1 509.2 TARE #1 154.1 220.2 191.8 220.4 WW+T#2 WD+T#2 TARE #2 MOIST. 8.8 10.7 13.2 14.9 DRY DENS. 108.5 111.2 112.5 107.9 TEST RESULTS Material Description Maximum Optimum dry moisture density = 12.5 = 113.0 pcf Silty, Clayey Sand Remarks: These were tested. reproduced, approval Moisture/density accordance performed analysis D1140. test results apply only to the samples which the testing report shall not be except in full, without the written of Kumar and Associates, Inc. relationships performed in with ASTM D698, D1557. Atterberg limits in accordance with ASTM D4318 sieve performed in accordance with ASTM D422, Project No. 23—1-750 Client: Project: Mountain Peak Power O Location: TRT #2 Depth: 1'-5' Sample Number: 3207 Checked by: JJM Title: Lab Manager 23-1-750 Kumar & Associates MOISTURE —DENSITY RELATIONSHIPS Fig. 13 g\231750-11 to 14.dwg COMPACTION TEST REPORT Curve No. 3208 111 ZAV SpG 2.60 Preparation Method 11.7%, 109.9 pcf Rammer: Wt. 5.5 lb. Drop 12 in. Type Manual Layers: No. 3 Blows per 25 Mold Size 0.03333 cu. ft. Test Performed on Material Passing #4 Sieve %>#4 0 %<No.200 13 ) ry d Atterberg (D 4318): LL 17 PI 2 NM (D 2216) Sp.G. (D 854) 2.6 uscs (D 2487) SM AASHTO (M 145) Date: Sampled 12/26/23 Received 12/26/23 Tested 12/26/23 6 8 10 12 14 16 18 Tested By AS Water COMPACTION ASTM D content, 698-12 TESTING Method DATA A Standard SIEVE TEST RESULTS 1 2 3 4 5 6 Opening Size % Passing Specs. WM + WS 6138.0 6212.0 6238.0 6224.0 WM 4365.0 4365.0 4365.0 4365.0 WW + T #1 420.4 382.6 774.6 394.5 WD + T #1 398.9 359.4 741.4 362.6 TARE #1 152.2 150.0 495.5 153.7 WW+T#2 WD+T#2 TARE #2 MOIST. 8.7 11.1 13.5 15.3 DRY DENS. 107.6 109.8 108.9 106.5 TEST RESULTS Material Description Maximum Optimum dry moisture density = 11.7 = 109.9 pcf Silty Sand Remarks: These were tested. reproduced, approval Moisture/density accordance performed analysis D1140. test results apply only to the samples which the testing report shall not be except in full, without the written of Kumar and Associates, Inc. relationships performed in with ASTM D698, D1557. Atterberg limits in accordance with ASTM D4318 sieve performed in accordance with ASTM D422, Project No. 23—1-750 Client: Project: Mountain Peak Power O Location: TRT #3 Depth: 1'-5' Sample Number: 3208 Checked by: JJM Title: Lab Manager 23-1-750 Kumar & Associates MOISTURE —DENSITY RELATIONSHIPS Fig. 14 *SAMPLE SOIL LOCATION: DATE GRAVEL: LIQUID not in 5 TEST SPECIMEN 1 2 3 4 R —VALUE (300 psi) MOISTURE CONTENT (%) DENSITY (pcf) EXPANSION PRESSURE (psi) EXUDATION PRESSURE ((psi) R VALUE LESS THAN 5* EXTRUDED TYPE: SAMPLED: LIMIT: Lu D AROUND 100 9O 80 7O 6O 50 40 3O 20 10 O Clay FOLLOWER. PER ASTM STANDARDS, THE SAMPLE IS ASSIGNED WITH AN R —VALUE OF to Associates, D1140. LESS THAN the samples report shall without the with in accordance performed ASTM Inc. i Icy Lean m with 100 Sand 2OO (CL) 300 EXUDATION 400 PRESSURE 500 (psi) 600 7OO 8OO Boring 2 © 1'-5' 0 12/13/23 DATE 9 RECEIVED: 0 / INDEX: 12/13/23 DATE 81 TESTED: o / These which be written R D2844. with accordance 12/14/23 0 / SAND: SALT ANTI 28 CLAY: test results apply only were tested. The testing reproduced, except in full, approval of Kumar & —value performed in accordance Atterberg limits performed ASTM D4318. Sieve analyses with ASTM D422, 44 PLASTICITY 23-1-750 Kumar & Associates HVEEM—STABILOMETER TEST RESULTS Fig. 15 3 Cn 1- r 0 In N. M N al C 0 a 0 0 0, 0 a ag 0 . a c 0 4- 0 P 0 N. o^ N 0 N N N tal O 0 c / NEW Unconfined Comp (20000lbs) Specimen ID B1-24 Test Number 10356 Report Number 4085 Test Date 12/14/2023 1:10:08 PM Sample Dia.-inches Sample Area.-inches^2 Stress (PSI) Peak Load (lbs.) Comp. Str. (lbs./sf) cyo Strain at Failure Test Results 1.94 2.96 138.0 408 19,868 0.16 Testing Machine STM-20K 1105588 Load Cell S/N (TVI123194), Units (LBS ) 20000 Crosshead Speed ( Inches / min ) or Rate 0.03 Extension or Position Measured by XHD_100 ( XHD100 ) By : Date : 160.0 - 140.0 - 120.0 - 100.0 - 80.0 - 60.0 - 40.0 - 20.0 - 0.0 Stress (-Lbs / Inches 2) vs Extension (2)/0) I I 0.05 0.10 0.15 0.20 0.25 Job Name Mountain Peak Power Hole Number 1 _oad Rate= 0.5-2.0%/min Job Number 23-1-750 Operator Depth 24 Descr: Claystone Part Number Template No 29 14 -Dec -23 Kumar & Associates Length 2.72 Len/Dia Ratio 1.402 Min/Max Load Rate 0.25 2 3 - Kumar & Associates 2390 South Lipan Street Deriver, CO 80223 Tel 303-742-9700 FAX 303-742-9666 -/5 0 Kumar & Associates l_ N C i i Fl IFig,/ 1 6 Cn 1- r 0 In N. M N al C 0 a 0 4- 0 0, 0 a ag 0 . a c 0 4- 0 00 O N. o IN 0 N N N O 0 v c / NEW Unconfined Comp (20000lbs) Specimen ID B6@19 Test Number 10357 Report Number 4086 Test Date 12/14/2023 1:24:39 PM Sample Dia.-inches Sample Area.-inches^2 Stress (PSI) Peak Load (lbs.) Comp. Str. (Ibs./sf) Strain at Failure Test Results 1.94 2.96 47.8 141 6,887 0.03 Testing Machine STM-20K 1105588 Load Cell S/N (TVI123194), Units (LBS ) 20000 Crosshead Speed ( Inches / min ) or Rate 0.03 Extension or Position Measured by XHD_100 ( XHD100 ) By : Date : 60.0 - 50.0 - 40.0 - 30.0 - 20.0 - 10.0 - 0.0 Stress (-Lbs / Inches 2) vs Extension (-%) N 0.01 I I I I 1 I 0.02 0.03 0.04 0.05 0.06 0.07 Job Name Mountain Peak Power Hole Number 6 _oad Rate= 0.5-2.0°/0/min Job Number 23-1-750 Operator Depth 19 Descr: Claystone Part Number Template No 29 14 -Dec -23 Kumar & Associates Length 2.91 Len/Dia Ratio 1.5 Min/Max Load Rate 0.25 23 - Kumar & Associates 2390 South Lipan Street Denver, CO 80223 Tel 303-742-9700 FAX 303-742-9666 -/5 0 Kumar & Associates l_ N C i i 3 Cn i 0 In N. M N al C 0 a 0 4- 0 0, 0 a ag 0 . a c 0 4- 0 00 O N. o IN 0 N N N O 0 v �rL c / NEW Unconfined Comp (20000lbs) Specimen ID B8@29 Test Number 10358 Report Number 4087 Test Date 12/14/2023 1:41:58 PM Sample Dia.-inches Sample Area.-inches^2 Stress (PSI) Peak Load (lbs.) Comp. Str. (Ibs./sf) Strain at Failure Test Results 1.94 2.96 84.4 250 12,153 0.07 Testing Machine STM-20K 1105588 Load Cell S/N (TVI123194), Units (LBS ) 20000 Crosshead Speed ( Inches / min ) or Rate 0.03 Extension or Position Measured by XHD_100 ( XHD100 ) Stress (-Lbs / Inches 2) vs Extension (-%) 90.0 - 80.0 - 70.0 - 60.0 - 50.0 - 40.0 - 30.0 - 0.0 1 1 f 1 I 1 By : Date : 0.02 0.04 0.06 0.08 0.10 0.12 Job Name Mountain Peak Power Hole Number 8 _oad Rate= 0.5-2.0°/0/min Job Number 23-1-750 Operator Depth 29 Descr: Claystone Part Number Template No 29 14 -Dec -23 Kumar & Associates Length 3.75 Len/Dia Ratio 1.93 Min/Max Load Rate 0.25 2 3 - Kumar & Associates 2390 South Lipan Street Denver, CO 80223 Tel 303-742-9700 FAX 303-742-9666 -T5 0 Kumar & Associates l_ N C i i LtS 1 8 cn 1O N 0 O, T Lc) N O C t w C O C O -47 4- to t_ m O a. a m a. C v C O a ufi O N A: I O M N M N N O O N . r O U rm a. c o -U)> 40.000 35.000 30.000 25.000 E O 20.000 co Ili 15.000 10.000 5.000 0 I 1- I h I f t 1 1 ' s 0 2 4 6 8 ELECTRODE SPACING (m) 10 12 14 LEGEND: TEST 1 - EAST -WEST TEST 1 - NORTH -SOUTH 23-1-750 I Kumar & Associates ELECTRICAL RESISTIVITY TESTING IFig. 19 140.000 120.000 100.000 on 3 N O 4- Station\ Drafting\ 231 750-1 9 L m 3 O a. S O m a. c '0 c J O M o a to o N h 1 o- 1 1 M N a/� N N O N ON a O O U r* c / ^80.000 E O I- 60.000 w CC 40.000 20.000 0 N 0 2 4 6 8 ELECTRODE SPACING (m) 10 12 14 LEGEND: TEST 2 - EAST -WEST TEST 2 - NORTH -SOUTH 23-1-750 Kumar & Associates I ELECTRICAL RESISTIVITY TESTING IFig. 20 on N O 4- Station\ Drafting\ 231 750-1 9 L m 3 0 a. S C U, a. C 'Es c J O M o a to o N h 1 o- 1 1 M N a/� N N O N ON a h O U r* c / 90.000 80.000 70.000 60.000 E 50.000 O I- 40.000 I - w CC 30.000 20.000 10.000 0 \ 0 2 4 6 8 ELECTRODE SPACING (m) 10 12 14 LEGEND: TEST 3 - EAST -WEST TEST 3 - NORTH -SOUTH 23-1-750 Kumar & Associates I ELECTRICAL RESISTIVITY TESTING IFig. 21 cnnn 0 10 20 30 40 50 60 0 0 0 I p Q k 2000 .1.—I I A ' 1000 •r.. 0 - o 10 20 MOISTURE 30 40 (%) 50 60 CURVE SYMBOL IDENTIFICATION SAMPLE SOIL OR BEDROCK TYPE RESISTIVITY (ohm MINIMUM —cm) RESISTIVITY AT IN SITU MOISTURE CONTENT (ohm —cm) • BORING 3 © 5 FT. Lean Clay with Sand (CL) 726 920 O BORING 2 © 1'-5' Lean Clay with Sand (CL) 470 575* * AT THE OPTIMUM MOISTURE CONTENT 23-1 -750 Kumar & Associates LABORATORY RESISTIVITY RESULTS Fig. 22 THERMAL DRYOUT CURVE 300 Interpolated Rho (C cm/W) ak in N _0 M N I Q In M N a C L G i 0 ra 47/3 3 O I 0 C 0 0 as LOW) C:I n At: I 0 I i M 04 Na in d N V a 250 200 E 0 150 U O Iz 100 50 0 • Measured Rho (C cm/W) 0% 5% 10% 15% Gravi metric Water Content (percent) 20% 25% Sample of: Silty Sand From: TRT #1 @ 1'-5' Gravel: Sand: Silt/Clay: LL: PI: OMC DD 0 % 84 % 16 % NV NP 11.3 % 113.1 pcf GWC (percent) Measured Rho (C cm/W) 0.0 17.6 11.9 Average Density as Tested 213.7 44.8 45.5 107.6 pcf 95.2 % compaction 23-1 -750 Kumar & Associates I THERMAL DRYOUT CURVE a Fig. 23 THERMAL DRYOUT CURVE 300 Interpolated Rho (C cm/W) in N _0 M N I Q In M N O) C L G i 0 ra 47/3 3 O I 0 C 0 0 as LOW) C:I n At: I 0 I i M 04 Na in d N V a 250 200 E 0 150 v O cc 100 50 0 • Measured Rho (C cm/W) 0% 5% 10% 15% Gravi metri c Water Content (percent) 20% 25% Sample of: Silty, Clayey Sand From: TRT #2 @ 1'-5' Gravel: Sand: Silt/Clay: LL: PI: OMC DD 0 % 77 % 23 % 19 4 12.5 % 113.0 pcf GWC (percent) Measured Rho (C cm/W) 0.0 17.9 12.9 Average Density as Tested 230.9 41.4 49.2 107.2 pcf 94.8 % compaction 23-1-750 Kumar & Associates I THERMAL DRYOUT CURVE a Fig. 24 THERMAL DRYOUT CURVE 300 Interpolated Rho (C cm/W) 01 3 IA N _0 M N I Q M N O) C 1.- 0 i 0 D 47/3 O a. 0 C 0 0 as Loin C:I n AZ I 0 I i M 04 NI in d N V a 250 200 a E 0 150 v O ec 100 50 0 5% 10% 15% 20% 0% • Measured Rho (C cm/W) Gra vi metri c Water Content (percent) 25% Sample of: Silty Sand From: TRT #3 @ 1'-5' Gravel: Sand: Silt/Clay: LL: PI: OMC DD 0 % 87 % 13 17 2 11.7 % 109.9 pcf GWC (percent) Measured Rho (C cm/W) 0.0 15.6 12.1 Average Density as Tested 217.4 46.2 50.6 105.4 pcf 95.9 % compaction 23-1-750 Kumar & Associates I THERMAL DRYOUT CURVE a Fig. 25 TABLE I SUMMARY OF LABORATORY TEST RESULTS PROJECT NO.: PROJECT NAME: DATE SAMPLED: DATE RECEIVED: 23-1-750 Mountain Peak Power Station 12/12/2023 12/13/2203 SAMPLE LOCATION TESTED DATE NATURAL MOISTURE CONTENT (%) NATURAL DENSITY DRY (pcf) GRADATION PERCENT PASSING NO. 200 SIEVE ATTERBERG LIMITS WATER SOLUBLE SULFATES (%) MINIMUM ELECTRICAL RESISTIVITY (ohm -cm) CHLORIDE CONTENT IN SOIL (%) pH R -VALUE @ 300 PSI UNCONFINED COMPRESSIVE STRENGTH (PSI) AASHTO CLASSIFICATION (group index) SOIL OR BEDROCK TYPE BORING DEPTH (feet) GRAVEL (%) SAND (%) LIQUID LIMIT (%) PLASTICITY INDEX (%) 1 2.5 12/14/23 7.6 104.7 75 31 15 A-6 (9) Lean Clay with Sand (CL) 1 24 12/14/23 17.0 111.2 97 56 38 138 Claystone Bedrock 2 1-5 12/14/23 17.9* 92.9* 81 44 28 0.22 470 <5 A-7-6 (22) Lean Clay with Sand (CL) 2 5 12/14/23 6.7 116.1 63 25 10 A-4 (4) Sandy Lean Clay (CL) 2 9 12/14/23 19.2 107.2 92 33 14 Lean Clay (CL) 3 1 12/14/23 12.5 114.9 54 26 13 A-6 (4) Sandy Lean Clay (CL) 3 5 12/14/23 17.0 107.1 85 30 14 0.01 726 A-6 (10) Lean Clay with Sand (CL) 3 19 12/14/23 19.9 107.7 Claystone Bedrock 4 7.5 12/14/23 19.6 102.0 74 39 23 Lean Clay with Sand (CL) 4 14 12/14/23 20.4 107.0 97 50 29 Claystone Bedrock 5 1 12/14/23 1.9 103.0 10 NV NP A -1-a (0) Poorly -Graded Sand (SP-SM) with Silt 5 5 12/14/23 13.5 112.2 82 31 15 A-6 (11) Lean Clay with Sand (CL) 6 9 12/14/23 18.5 109.0 92 35 17 Lean Clay (CL) 6 19 12/14/23 23.8 99.6 88 80 54 0.19 47.8 Claystone Bedrock 7 2.5 12/14/23 17.1 97.8 84 31 16 A-6 (12) Lean Clay with Sand (CL) 7 7.5 12/14/23 11.1 94.8 40 19 5 Silty Clayey Sand (SC-SM) 8 5 12/14/23 8.7 95.0 62 28 12 A-6 (5) Sandy Lean Clay (CL) 8 29 12/14/23 16.6 114.9 96 53 34 84.4 Claystone Bedrock Test Pit 4 12/14/23 1.9 0 91 9 NV NP A-3 (0) Poorly -Graded Sand with Silt (SP-SM) Test Pit 8 12/14/23 9.8 60 23 7 Sandy Silty Clay (CL -ML) TRT #1 1-5 12/26/23 11.3* 113.1* 16 NV NP 0.005 5.67 Silty Sand (SM) TRT #2 1-5 12/26/23 12.5* 113.0* 23 19 4 0.005 6.60 Silty Claey Sand (SC-SM) TRT #3 1-5 12/26/23 11.7* 109.9* 3 17 2 0.005 5.54 Silty Sand (SM) *Optimum Moisture Content and Maximum Dry Density Per ASTM D698 TRT = Thermal Resistivity Test Location Hello