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HomeMy WebLinkAbout20252595.tiffStructural Geotechnical Materials Testing Forensic SUBSURFACE SOIL INVESTIGATION Respectfully Submitted, Denver Zoological Foundation The Preserve Weld County, Colorado PREPARED FOR: Baseline Engineering Corporation 112 N. Rubey Dr., #210 Golden, CO 80403 JOB NO. 197741 January 3, 2025 Reviewed by, RMG — Rocky Mountain Group RMG — Rocky Mountain Group Matthew Cherney, E.I. Tony Munger, P.E. Geotechnical Staff Engineer Sr. Geotechnical Project Manager TABLE OF CONTENTS GENERAL SITE AND PROJECT DESCRIPTION 3 Project Description and Scope of Work 3 Existing Site Conditions 3 Previous Studies and Field Investigation 3 FIELD INVESTIGATION AND LABORATORY TESTING 3 Drilling 3 Laboratory Testing 3 SUBSURFACE CONDITIONS 4 Subsurface Materials 4 Groundwater 4 Soil Parameters 4 Seismic Design 4 CONCLUSIONS AND RECOMMENDATIONS 5 Geotechnical Considerations 5 Site Preparation 5 Foundation Recommendations 6 Open Excavation Observations 6 Floor Slabs 6 Exterior Concrete Flatwork 7 Lateral Earth Pressures 7 CONSTRUCTION CONSIDERATIONS 7 Surface Grading and Drainage 7 Perimeter Drain 8 Concrete 8 Exterior Backfill 8 Structural Fill - General 9 CLOSING 9 FIGURES Site Vicinity Map 1 Test Boring Location Plan 2 Explanation of Test Boring Logs 3 Test Boring Logs 4-6 Summary of Laboratory Test Results 7 Soil Classification Data 8 Swell/Consolidation Test Results 9 RMG — Rocky Mountain Group 2 RMG Job No. 197741 GENERAL SITE AND PROJECT DESCRIPTION Project Description and Scope of Work RMG has completed a geotechnical investigation for the proposed Pre -Engineered Metal Building (PEMB) at Canal Road in the southeastern portion of Weld County, Colorado. The purpose of the investigation was to evaluate the subsurface soil conditions and provide geotechnical design and construction criteria for the project. RMG understands the PEMB is to be a one story, 50' x 100' structure with 20'- 0" eave heights and an interior clear span height of approximately 24' - 7 9/16". Existing Site Conditions The site is undeveloped and is currently vegetated with native grass and weeds. The location of the site is shown on the Site Vicinity Map, Figure 1. Previous Studies and Field Investigation Reports of previous geotechnical engineering/geologic investigations for this site were available for our review and are listed below: 1. Preliminary Geotechnical Evaluation, The Preserve, Weld County, Colorado, prepared by Ground Engineering, Job No. 24-3561, dated June 27, 2024. The findings, conclusions and recommendations contained in that report were considered during the preparation of this report. FIELD INVESTIGATION AND LABORATORY TESTING Drilling The subsurface conditions on the site were investigated by drilling five exploratory test borings to depths of approximately 20 to 40 feet within the proposed building footprint. The approximate locations of the test borings are presented in the Test Boring Location Plan, Figure 2. The test borings were advanced with a power -driven, continuous -flight auger drill rig. Soil samples were obtained in general accordance with ASTM D-1586 utilizing a 2 -inch OD split -barrel sampler or in general accordance with ASTM D-3550 utilizing a 21/2 -inch OD modified California sampler. Samples were returned to RMG's materials testing laboratory for testing and analysis. An Explanation of Test Boring Logs is presented in Figure 3. The Test Boring Logs are presented in Figures 4 through 6. Laboratory Testing The moisture content for the recovered samples was obtained in the laboratory. Grain -size analysis, Atterberg Limits, and Denver Swell/Consolidation tests were performed on selected samples for purposes of classification and to develop pertinent engineering properties. A Summary of Laboratory Test Results RMG — Rocky Mountain Group 3 RMG Job No. 197741 is presented in Figure 7. Soil Classification Data is presented in Figure 8. Swell/Consolidation Test Results are presented in Figure 9. SUBSURFACE CONDITIONS Subsurface Materials The test borings revealed the soil strata across the site to be relatively consistent from boring to boring. The subsurface materials encountered in the test borings consisted of native silty to clayey sand and native siltstone. However, the materials within each stratum were encountered at variable densities. Additional descriptions and the interpreted distribution (approximate depths) of the subsurface materials are presented on the Test Boring Logs. The classifications shown on the logs are based upon visual classification of the samples at the depths indicated. Stratification lines shown on the logs represent the approximate boundaries between material types and the actual transitions may be gradual and vary with location. Groundwater Groundwater was observed at a depth of approximately 22 feet in the test boring B5 at the time of drilling. Groundwater was not encountered in the remaining test borings at the time of drilling. Groundwater is not expected to be a significant factor in foundation design. Fluctuations in groundwater and subsurface moisture conditions may occur due to seasonal variations in rainfall and other factors not readily apparent at this time. Soil Parameters The following table presents estimated in -situ soil parameters. Soil Description Unit Active Earth Pressure Ka Passive Modulus Elasticity of Poisson's Friction Angle At -Rest Earth Pressure Ko Weight (lb/fl3) Ratio µs Earth Es (lb/in) Pressure Kp (degree) Silty to Clayey Sand 105 27 0.376 2.66 0.546 1,500 0.20 Seismic Design In accordance with the Minimum Design Loads and Associated Criteria for Buildings and Other Structures, ASCE/SEI 7-16, seismic design parameters have been determined for this site. The seismic site class has been interpreted from the results of the soil test borings drilled within the project site. The Applied Technology Council seismic design tool has been used to determine the seismic response acceleration parameters. The soil on this site is not considered susceptible to liquefaction. RMG — Rocky Mountain Group 4 RMG Job No. 197741 The following recommended seismic design parameters are based upon Seismic Site Class D, and a 2 - percent probability of exceedance in 50 years. The Seismic Design Category is "B". Period (sec) Site Coefficients Design Spectral Response Mapped MCE Adjusted MCE Spectral Response Acceleration (g) Spectral Response Acceleration (g) Acceleration (g) 0.2 Ss O.131 Fa 1.6 Sms 0.209 Sas O.139 1.O Si 0.046 2.4 Smi 0.112 Say 0.074 Fv Notes: MCE = Maximum Considered Earthquake g = acceleration due to gravity CONCLUSIONS AND RECOMMENDATIONS The following discussion is based on the subsurface conditions encountered in the test borings and the project characteristics previously described. If conditions are different from those described in this report or the project characteristics change, RMG should be retained to review and revise our recommendations as necessary. Geotechnical Considerations Shallow, spread footing foundation systems are commonly utilized for similar soil conditions in this region. Based on the site and soil conditions encountered, a shallow, spread footing foundation is anticipated to be more economically feasible than other foundation alternatives. It is our opinion that a shallow, spread footing foundation system is suitable for use, provided that the recommendations presented herein are strictly adhered to. Soil improvements required to achieve the allowable bearing capacity presented herein are discussed below. However, it should be recognized that a shallow, spread footing is only one available foundation system. One alternative that is generally considered to provide a lower risk of foundation movement (and associated damage) is a foundation system consisting of cast -in -place concrete caissons (drilled piers) embedded into the underlying bedrock used in conjunction with an elevated structural floor system (crawlspace). The decision regarding which foundation system alternative to install at the residence is entirely the decision of the Builder/Developer, and not RMG. Contact RMG prior to construction if recommendations for a drilled pier foundation (or other foundation alternatives) are desired. Site Preparation Standard Penetration Test blow counts vary across the site and with depth. Due to this variability we recommend removing (overexcavating) the foundation areas and backfilling with compacted structural fill. The on -site material is suitable for use as structural fill. Site preparation should include clearing and grubbing the site of all vegetation, topsoil, and any other deleterious material within the construction area and disposing this material appropriately. Following clearing and grubbing, the area within the foundation footprint and a 3 -foot perimeter beyond should be overexcavated 3 feet below the bottom of footing elevation. The excavated material may be stockpiled for reuse as structural fill. An Open Excavation RMG — Rocky Mountain Group 5 RMG Job No. 197741 Observation should be made at this point to verify soil conditions are as reported in the soil boring logs herein. Upon verification, the upper 6 inches of the exposed subsurface soils should then be scarified and moisture conditioned to facilitate compaction (usually within 2 percent of the optimum moisture content) and compacted to a minimum of 95 percent of the maximum dry density as determined by the Modified Proctor test (ASTM D-1557) or 98 percent of the maximum dry density as determined by the Standard Proctor test (ASTM D-698) prior to placing structural fill. After compaction of the exposed subgrade, the native material previously removed may be used as structural fill to bring the site to bottom -of -footing grade. The material should not be excessively wet, should be free of organic matter and construction debris, and should not contain rock fragments greater than 3 -inches in any dimension. The fill material should be moisture -conditioned to facilitate compaction (usually within 2 percent of the optimum moisture content) and placed in lifts of not more than 10 inches. Each loose lift should be compacted to a minimum of 95 percent of Modified Proctor maximum dry density as determined by the Modified Proctor test (ASTM D-1557) or 98 percent of the maximum dry density as determined by the Standard Proctor test (ASTM D-698). The first density tests should be conducted when 12 inches of compacted fill have been placed. Foundation Recommendations Structures may be supported on shallow foundations bearing on approved soils when prepared in accordance with the recommendations above. When so prepared, a maximum allowable bearing pressure of 1,600 psf with no minimum dead load requirement may be used for design. The foundation design should be prepared by a qualified Colorado Registered Professional Engineer using the recommendations presented in this report. This foundation system should be designed to span a minimum of 10 feet under the design loads. The bottoms of exterior foundations should be at least 30 inches below finished grade for frost protection. When prepared and properly compacted, total settlement of 1 -inch or less with differential settlement on the order of 1/2 inch or less is estimated. Settlement in granular material generally occurs relatively rapidly with construction loads. Long term consolidation settlement should not be an issue, provided that the site material is prepared as recommended above. Open Excavation Observations As referenced above, foundation excavations should be observed by RMG prior to placing structural fill, forms, or concrete to verify the foundation bearing conditions for each structure. Based on the conditions observed in the foundation excavation, the recommendations made at the time of construction may vary from those contained herein. In the case of differences, the Open Excavation Observation report shall be considered to be the governing document to be used to modify the site preparation recommendations as necessary. Floor Slabs The in -situ sand soil exhibited no swell potential in laboratory testing. The on -site sand soils are suitable for use below slab. Any fill material placed below slabs should be granular, non -expansive material to reduce the potential for slab movement. If they have been allowed to remain exposed to weather for a significant period of time after completion of the recommended overexcavation and replacement, areas under floor slabs should be re-overexcavated a RMG — Rocky Mountain Group 6 RMG Job No. 197741 minimum of 1 -foot. The upper 6 inches of the exposed subsurface soils should then be scarified and moisture -conditioned to facilitate compaction (usually within 2 percent of the optimum moisture content) and compacted to a minimum of 95 percent of the maximum dry density as determined by the Modified Proctor test (ASTM D-1557) or 98 percent of the maximum dry density as determined by the Standard Proctor test (ASTM D-698) prior to placing structural fill. Floor slabs should bear upon a minimum of 1 - foot of structural fill compacted to a minimum of 95 percent of Modified Proctor maximum dry density as determined by the Modified Proctor test (ASTM D-1557) or 98 percent of the maximum dry density as determined by the Standard Proctor test (ASTM D-698). Non-structural slabs should be isolated from foundation members with expansion material. To reduce the potential for concrete curling, a minimum 3 - inch layer of 3/4 -inch crushed stone over 6 -mil vapor retarder may be placed atop the compacted structural fill. A conventionally -reinforced or post -tensioned slab supported on stemwalls or grade beams may also be considered for strength and to reduce the potential for movement, curling, and differential settlement. Exterior Concrete Flatwork Reinforced concrete exterior slabs should be constructed similarly to floor slabs on compacted structural fill, with the additional caveat they be isolated from the building with expansion material and have a downturned reinforced thickened edge. Conventionally -reinforced or post -tensioned slabs supported on stemwalls or grade beams may also be considered to reduce the potential for movement, curling, and differential settlement. Lateral Earth Pressures Foundation and basement walls should be designed to resist lateral pressures. For non -expansive backfill materials, we recommend an equivalent fluid pressure of 40 pcf for design. Expansive soils or bedrock should not be used as backfill against walls. The above lateral pressure applies to level, drained backfill conditions. Equivalent Fluid Pressures for sloping/undrained conditions should be determined on an individual basis. CONSTRUCTION CONSIDERATIONS Surface Grading and Drainage A contributing factor to foundation settlement and floor slab heave in Colorado Front Range soils is the introduction of excess water. Improper site grading and irrigation water are respectively the most common cause and source of excess water. The ground surface should be sloped from the building with a minimum gradient of 10 percent for the first 10 feet. This is equivalent to 12 inches of fall across this 10 -foot zone. Where a 10 -foot zone cannot be achieved, a well-defined swale should be created a minimum 5 feet from the foundation and parallel with the wall, with a minimum slope of 2 percent to collect the surface water and transport it around and away from the structure. Roof drains should extend across backfill zones and landscaped areas to a region that is graded to direct flow away from the structure(s). Future maintenance operations should include activities to maintain the surface grading and drainage recommendations herein to help prevent water from being directed toward and/or ponding near the foundations. Landscaping should be selected to reduce irrigation requirements. Plants used close to foundation walls should be limited to those with low moisture requirements and irrigated grass should not be located within 5 feet of the foundation. To help control weed growth, geotextiles should be used below landscaped areas adjacent to foundations. Impervious plastic membranes are not recommended. Irrigation devices should RMG — Rocky Mountain Group 7 RMG Job No. 197741 not be placed within 5 feet of the foundation. Irrigation should be limited to the amount sufficient to maintain vegetation. Application of excess water will increase the likelihood of slab and foundation movements. Perimeter Drain The site soil is generally anticipated to be well -draining, and groundwater was not encountered at depths anticipated to impact the proposed construction. A subsurface perimeter drain is recommended around portions of the structure which will have habitable or storage space located below the finished ground surface. This includes crawlspace areas if applicable. Where main -level slab -on -grade foundation systems are utilized, a subsurface perimeter drain will not be required around the foundation. An underslab drain is not anticipated to be necessary. Concrete Sulfate testing was performed on selected samples based on ASTM C1580. Test results showed 0.00% by weight, indicating the soils present Class 0 (negligible) sulfate exposure. Based on these results Type I/II cement or an equivalent mixture according to ACI 201.2R-10 is suggested for concrete in contact with the subsurface materials. Cement type shall be designed and approved by a licensed Colorado Professional Engineer and Foundation Designer. Calcium chloride should not be used for the onsite soils. The concrete should not be placed on frozen ground. If placed during periods of cold temperatures, the concrete should be kept from freezing. This may require covering the concrete with insulated blankets and heating. Concrete work should be completed in accordance with the latest applicable guidelines and standards published by ACI. Exterior Backfill Backfill around foundation stemwalls and other buried structures should be placed in loose lifts of not more than 10 -inches, moisture conditioned to facilitate compaction (usually within 2 percent of the optimum moisture content) and compacted to 85 percent of the maximum dry density as determined by the Modified Proctor test (ASTM D-1557) or to 92 percent of the maximum dry density as determined by the Standard Proctor test (ASTM D-698) on exterior sides of walls in landscaped areas. In areas where backfill supports pavement and concrete flatwork, the materials should be compacted to 92 percent of the maximum dry density as determined by the Modified Proctor test (ASTM D-1557) or to 95 percent of the maximum dry density as determined by the Standard Proctor test (ASTM D-698). Fill placed on slopes should be benched into the slope. Maximum bench heights should not exceed 4 feet, and bench widths should be wide enough to accommodate compaction equipment. The appropriate government/utility specifications should be used for fill placed in utility trenches. If material is imported for backfill, the material should be approved by the Geotechnical Engineer prior to hauling it to the site. The backfill should not be placed on frozen subgrade or allowed to freeze during moisture conditioning and placement. Backfill should be compacted by mechanical means, and foundation walls should be braced during backfilling and compaction. RMG — Rocky Mountain Group 8 RMG Job No. 197741 Structural Fill - General Areas to receive structural fill should have topsoil, organic material, or debris removed. The upper 6 inches of the exposed surface soils should be scarified and moisture -conditioned to facilitate compaction (usually within 2 percent of the optimum moisture content) and compacted to a minimum of 95 percent of the maximum dry density as determined by the Modified Proctor test (ASTM D-1557) or to 98 percent of the maximum dry density as determined by the Standard Proctor test (ASTM D-698) prior to placing structural fill. Structural fill placed on slopes should be benched into the slope. Maximum bench heights should not exceed 4 feet, and bench widths should be wide enough to accommodate compaction equipment. Structural fill should be placed in loose lifts of not more than 10 -inches, moisture -conditioned to facilitate compaction (usually within 2 percent of the optimum moisture content) and compacted to a minimum of 95 percent of the maximum dry density as determined by the Modified Proctor test (ASTM D-1557) or to 98 percent of the maximum dry density as determined by the Standard Proctor test (ASTM D-698). The materials should be compacted by mechanical means. Materials used for structural fill should be approved by the RMG prior to use. Structural fill should not be placed on frozen subgrade or allowed to freeze during moisture conditioning and placement. To verify the condition of the compacted soils, density tests should be performed during placement. The first density tests should be conducted when 24 inches of fill have been placed. CLOSING This report has been prepared for the exclusive purpose of providing geotechnical engineering information and recommendations for development described in this report. RMG should be retained to review the final construction documents prior to construction to verify our findings, conclusions and recommendations have been appropriately implemented. This report has been prepared for the exclusive use by Baseline Engineering Corporation for application as an aid in the design and construction of the proposed development in accordance with generally accepted geotechnical engineering practices. The analyses and recommendations in this report are based in part upon data obtained from test borings, site observations and the information presented in referenced reports. The nature and extent of variations may not become evident until construction. If variations then become evident, RMG must be retained to review and revise the recommendations presented in this report as appropriate. Our professional services were performed using that degree of care and skill ordinarily exercised, under similar circumstances, by geotechnical engineers practicing in this or similar localities. RMG does not warrant the work of regulatory agencies or other third parties supplying information which may have been used during the preparation of this report. No warranty, express or implied is made by the preparation of this report. Third parties reviewing this report should draw their own conclusions regarding site conditions and specific construction techniques to be used on this project. The scope of services for this project does not include, either specifically or by implication, environmental assessment of the site or identification of contaminated or hazardous materials or conditions. Development of recommendations for the mitigation of environmentally related conditions, including but RMG — Rocky Mountain Group 9 RMG Job No. 197741 not limited to biological or toxicological issues, are beyond the scope of this report. If the Client desires investigation into the potential for such contamination or conditions, other studies should be undertaken. If we can be of further assistance in discussing the contents of this report or analysis of the proposed development, from a geotechnical engineering point -of -view, please feel free to contact us. RMG — Rocky Mountain Group 10 RMG Job No. 197741 FIGURES SITE 401 rRoggen NOT TO SCALE sari - - Orchard i tsse, —ems- •Wiggins Architecture Structural Geotechnical Engineers / Architects Materials Testing Forensics Civil / Planning NORTHERN COLORADO OFFICE 7292 GREENRIDGE ROAD, UNIT #106, WINDSOR, CO 8O55O (970) 330-1071 - WWW.RMGENGINEERS.COM SOUTHERN COLORADO. DENVER METRO, NORTHERN COLORADO J SITE VICINITY MAP CANAL ROAD PARCEL NO. 096733100004 WELD COUNTY, COLORADO BASELINE ENGINEERING CORPORATION J JOB No. 197741 FIG No. 1 DATE 1-3-2025 AMor AMor S TB -5 per „Jr • O. 1 �$ % T6-4 -17r7C-\\::\ S 4 I S TB -3 i 1 i S89t33'02"W 2,627.00, r ear S rB-z i S al Oen S to-i __ J S89u33hi 2"W 2.627.; I S DENOTES APPROXIMATE LOCATION OF TEST ISOR INGS NOT TO SCALE Architecture Structural Geotechnical Engineers I Architects NORTHERN COLORADO OFFICE 7292 GREENRIDGE ROAD, UNIT #108, WINDSOR, CO 80550 (970) 33❑ -1071 - WWW.RMGENGINEERS.C❑M SOUTHERN COLORADO, DENVER METRO, NORTHERN COLORADO Materials Testing Forensics Civil / Planning TEST BORING Th LOCATION PLAN CANAL ROAD PARCEL NO. 096733100004 WELD COUNTY, COLORADO BASEUNE EN9INEERINCq CORPORATION Thk JOB No. 197741 FIC No. 2 ATE 1-3-2025 J, SOILS DESCRIPTION • CLAYEY SAND SILTSTONE LTSTO N E SILTY SAND UNLESS NOTED OTHERWISE, ALL LABORATORY TESTS PRESENTED HEREIN WERE PERFORMED BY: RMG - ROCKY MOUNTAIN GROUP 7292 GREENRIDGE ROAD, UNIT 108 WINDSOR, COLORADO 80550 SYMBOLS AND NOTES XX XX H 4.5 WATER CONTENT (%) STANDARD PENETRATION TEST - MADE BY DRIVING A SPLIT -BARREL SAMPLER INTO THE SOIL BY DROPPING A 140 LB. HAMMER 30", IN GENERAL ACCORDANCE WITH ASTM D-1586. NUMBER INDICATES NUMBER OF HAMMER BLOWS PER FOOT (UNLESS OTHERWISE INDICATED). UNDISTURBED CALIFORNIA SAMPLE - MADE BY DRIVING A RING -LINED SAMPLER INTO THE SOIL BY DROPPING A 140 LB. HAMMER 30", IN GENERAL ACCORDANCE WITH ASTM D-3550. NUMBER INDICATES NUMBER OF HAMMER BLOWS PER FOOT (UNLESS OTHERWISE INDICATED). FREE WATER TABLE DEPTH AT WHICH BORING CAVED BULK DISTURBED BULK SAMPLE AUG AUGER "CUTTINGS" Structural Forensics ROCKY MOUNTAIN GROUP Colorado Springs: (Corporate Office) 5085 List Drive, Suite 200 Colorado Spings, CO 80918 (719) 548-0600 SOUTHERN COLORADO, DENVER METRO, NORTHERN COLORADO Geotechnical Materials Testing EXPLANATION OF TEST BORING LOGS J r JOB No. 197741 FIGURE No. 3 DATE Jan/03/2025 WATER CONTENT WATER CONTENT °/ TEST BORING: B1 DATE DRILLED: 11/20/24 NO GROUNDWATER ON 11/20/24 w TEST BORING: B2 DATE DRILLED: 11/20/24 NO GROUNDWATER ON 11/20/24 w BLOWS PER I BLOWS PER 0 m > 0 m > H (I 0_ Q (0 El Q co H SAND, medium SILTY, dense, light dry brown, to moist .a°.,.'G.;° :: ' � i . i°'; ;" :•L G L • . • i:: ••G i 4 • i• R •'' i 29 37 39 9.7 16.0 20.7 SAND, brown, dry to SILTY, medium moist light dense brown to dense, to _ - ;°... : :: i i • SAND, CLAYEY, brown with rust staining, medium dense to dense, moist 10 - SAND, dense, CLAYEY, brown, medium moist 15 15 SILTSTONE, medium tan to brown, hard, moist 20 x x x X x x SILTSTONE, tan to brown rust staining, medium hard, --moist with !- _ 20 x x x x x x v Structural Forensics ROCKY MOUNTAIN GROUP RMS Colorado Springs: (Corporate Office' 5085 List Drive, Suite 200 Colorado Spings, CO 80918 (719) 548-0600 SOUTHERN COLORADO, DENVER METRO, NORTHERN COLORADO Geotechnical Materials Testing J TEST BORING LOG JOB No. 197741 FIGURE No. 4 DATE Jan/03/2025 A _ / WATER CONTENT WATER CONTENT °/ TEST BORING: B3 DATE DRILLED: 11/20/24 NO GROUNDWATER ON 11/20/24 w TEST BORING: B4 DATE DRILLED: 11/20/24 NO GROUNDWATER ON 11/20/24 w BLOWS PER I BLOWS PER 0 m > 0 m > H (I 0_ Q (0 0_ Q co H SAND, brown, moist SILTY, very loose light brown to loose, to dry to _.>°.,.'4.';4 -.4' 5 :: •L i . 4 ; i . • L ;;', 4 i i • i >'°' : i ' c � > '4 i •4 :i 4. i°'; ' ''-'s > .L i G . • > L • i • • :;, a ,' .L, i • a` i ,' L. a ' f ' i i G ' 4 L i: L' ',L � i 4 ii R L' 4 i 4 4 ` 4 • a i 4 . i ii 4 4• iG • : ii Gi 4 ♦ i 4 a 4 4. i ..� ii 4 12 7 5 2 3 34 50/11 38 21.0 18.2 15.2 1.4 3.1 4.3 4.3 3.6 SAND, brown, loose, SILTY, dry light to brown to moist _ -'L 5 ,°.,.' .: L . 4 i a • 4 ; ..::L • f i . ' L '•. . . . 4, • i•' i 4 . . > a 4 • i 4 • • • a � 4 - • ' :; ` • •' ii. 4 4 'L a: .fa 4 ° . .•4 i f' , i 4. ` 4 > ,4 i` .•4 i 4 4• iG a • �4 i` , 4 9 9 7 5.4 3.6 3.3 4.8 - _ 10 10 J 15 15 J 20 20 _I J _ 25 SAND, staining, moist CLAYEY, brown dense to very dense, with rust 30 � � . . :. . . ' . 35 40 ROCKY MOUNTAIN GROUP Structural Forensics RMS Colorado Springs: (Corporate Office' 5085 List Drive, Suite 200 Colorado Spings, CO 80918 (719) 548-0600 SOUTHERN COLORADO, DENVER METRO, NORTHERN COLORADO Geotechnical Materials Testing J TEST BORING LOG JOB No. 197741 FIGURE No. 5 DATE Jan/03/2025 WATER CONTENT TEST BORING: B5 DATE DRILLED: 11/20/24 GROUNDWATER @ 22.0 ' 11/20/24 J 0 J J BLOWS PER I co > H (I 0_ < ' SAND, to dense, SILTY, dry light to moist brown, loose _ :°.;.'G i 4 if . - . i. •4 . - i i i. G k': i f .1 • 4 . i i i .f 4 4 ;, i 4 4 i 4. •. L• ` • ii R L 4 i 4 i 4 4 L' Li 4 4i i 9 30 12 50/8 50/9 50/11 50/7 50/5 2.4 6.1 17.8 24.9 25.4 23.4 28.9 29.9 _, _ _ 10 _ SAND, staining, CLAYEY, brown with rust medium dense, moist 15 "• _ SILTSTONE CLAYSTONE rust moist staining, to with seams, hard wet interbedded brown with to very hard, 20 x x X x x X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X _ - - 25 ' -X -X -X _X 30 a -X -X _X _ 35 _ _X -X 40 ROCKY MOUNTAIN GROUP Structural Forensics RMS Colorado Springs: (Corporate Office' 5085 List Drive, Suite 200 Colorado Spings, CO 80918 (719) 548-0600 SOUTHERN COLORADO, DENVER METRO, NORTHERN COLORADO Geotechnical Materials Testing J TEST BORING LOG JOB No. 197741 FIGURE No. 6 DATE Jan/03/2025 l 1 Test Boring No. Depth p Water Content a (/o) Des (pcf) Liquid Limit Plasticity Index Retained No.4 Sieve in Passing No. 200 Sieve % Collapse Swelll Load Saturation (psf) at B1 4.0 2.6 98.6 NP NP 0.0 12.3 - 3.3 1,000 B1 9.0 9.7 B1 14.0 16.0 B1 19.0 20.7 B2 2.0 5.0 B2 7.0 10.7 B2 14.0 12.0 103.6 29 4 0.0 37.0 - 0.3 1,000 B2 19.0 21.4 B3 4.0 1.4 B3 9.0 3.1 B3 14.0 4.3 NP NP 0.0 8.5 B3 19.0 4.3 B3 24.0 3.6 B3 29.0 21.0 B3 34.0 18.2 B3 39.0 15.2 B4 2.0 5.4 NP NP 0.0 9.2 B4 7.0 3.6 B4 14.0 3.3 B4 19.0 4.8 B5 4.0 2.4 B5 9.0 6.1 107.1 NP NP 0.0 24.0 - 0.8 1,000 B5 14.0 17.8 B5 19.0 24.9 B5 24.0 25.4 B5 29.0 23.4 B5 34.0 28.9 B5 39.0 29.9 Structural Forensics ROCKY MOUNTAIN GROUP Colorado Springs: (Corporate Office) 5085 List Drive, Suite 200 Colorado Spings, CO 80918 (719) 548-0600 SOUTHERN COLORADO, DENVER METRO, NORTHERN COLORADO Geotechnical Materials Testing Th r SUMMARY OF LABORATORY TEST RESULTS J r JOB No. 197741 FIGURE No. 7 PAGE 1 OF 1 DATE Jan/03/2025 C J 100 90 H80 CD 14:170 ›- c°60 O150 o_ I— 40 z w ct 30 w 0_ 20 10 0 U.S. SIEVE OPENING IN INCHES 3 1.5 1 3/4 1/23/8 U.S. SIEVE NUMBERS 4 8 10 20 40 100 HYDROMETER 200 100 10 1 0.1 GRAIN SIZE IN MILLIMETERS 0.01 0.001 COBBLES GRAVEL SAND SILT OR CLAY coarse fine coarse medium fine Test Boring Depth (ft) Classification LL PL PI e B1 4.0 SILTY SAND(SM) NP NP NP B2 14.0 SILTY SAND(SM) 29 25 4 B3 14.0 POORLY GRADED SAND with SILT(SP-SM) NP NP NP B4 2.0 POORLY GRADED SAND with SILT(SP-SM) NP NP NP B5 9.0 SILTY SAND(SM) NP NP NP Test Boring Depth (ft) %Gravel %Sand %Silt %Clay e B1 4.0 0.0 87.7 12.3 B2 14.0 0.0 63.0 37.0 B3 14.0 0.0 91.5 8.5 B4 2.0 0.0 90.8 9.2 B5 9.0 0.0 76.0 24.0 Structural Forensics ROCKY MOUNTAIN GROUP RISIG Colorado Springs: (Corporate Office) 5085 List Drive, Suite 200 Colorado Spings, CO 80918 (719) 548-0600 SOUTHERN COLORADO, DENVER METRO, NORTHERN COLORADO Geotechnical Materials Testing Th r SOIL CLASSIFICATION DATA r JOB No. 197741 FIGURE No. 8 DATE Jan/03/2025 J C r z 0 co z Q w X w z 0 Co w 0 0 U z 0 co z Q 0_ X w 0 z 0 COMPRESS COMPRESS K, 0 1 -2 -3 -4 -5 -6 -7 -8 100 0 1 -2 -3 -4 -5 -6 -7 1,000 APPLIED PRESSURE - PSF PROJECT: Denver Zoological Foundation Weld County, Colorado SAMPLE DESCRIPTION: Silty Sand NOTE: SAMPLE WAS INUNDATED WITH WATER AT 1,000 PSF 10,000 SAMPLE LOCATION: B1 @ 4 FT NATURAL DRY UNIT WEIGHT: 98.6 PCF NATURAL MOISTURE CONTENT: 2.6% PERCENT SWELL/COMPRESSION: - 3.3 -8 100 1,000 APPLIED PRESSURE - PSF PROJECT: Denver Zoological Foundation Weld County, Colorado SAMPLE DESCRIPTION: Clayey Sand NOTE: SAMPLE WAS INUNDATED WITH WATER AT 1,000 PSF SAMPLE LOCATION: B2 @ 14 FT NATURAL DRY UNIT WEIGHT: 103.6 PCF NATURAL MOISTURE CONTENT: 12.0% PERCENT SWELL/COMPRESSION: - 0.3 10,000 J Structural Forensics ROCKY MOUNTAIN GROUP M RMS Colorado Springs: (Corporate Office) 5085 List Drive, Suite 200 Colorado Spings, CO 80918 (719) 548-0600 SOUTHERN COLORADO, DENVER METRO, NORTHERN COLORADO Geotechnical Materials Testing 1 r M SWELL/CONSOLIDATION TEST RESULTS r JOB No. 197741 FIGURE No. 9 DATE Jan/03/2025 C J r z 0 co z Q 0 x w z 0 COMPRESS 0 -1 -2 -3 -4 -5 -6 -7 -8 100 1,000 APPLIED PRESSURE - PSF PROJECT: Denver Zoological Foundation Weld County, Colorado SAMPLE DESCRIPTION: Silty Sand NOTE: SAMPLE WAS INUNDATED WITH WATER AT 1,000 PSF SAMPLE LOCATION: B5 @ 9 FT NATURAL DRY UNIT WEIGHT: 107.1 PCF NATURAL MOISTURE CONTENT: 6.1% PERCENT SWELL/COMPRESSION: - 0.8 10,000 J Structural Forensics ROCKY MOUNTAIN GROUP M RMS Colorado Springs: (Corporate Office) 5085 List Drive, Suite 200 Colorado Spings, CO 80918 (719) 548-0600 SOUTHERN COLORADO, DENVER METRO, NORTHERN COLORADO Geotechnical Materials Testing 1 r M SWELL/CONSOLIDATION TEST RESULTS r JOB No. 197741 FIGURE No. 10 DATE Jan/03/2025 C J Hello