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Home My WebLink AboutGeotechnical Investigation 04.18.2022Huddleston-Berry Fngi111:cri11~ & resting, LLC T-Squared Mesa, LLC 2367 46 ½ Road DeBeque, Colorado 81630 Attention: Subject: Mr. Thorsten Zenglein Geotechnical Investigation 178 Eagle Ridge Drive Parachute, Colorado Dear Mr. Zenglein, 2789 Riverside Parkway Grand Junction, Colorado 81501 Phone: 970-255-8005 Info@huddlestonberry.com April 18, 2022 Project#02453-0002 This letter presents the results of a geotechnical investigation conducted by Huddleston-Berry Engineering & Testing, LLC (HBET) for 178 Eagle Ridge Drive in Parachute, Colorado. The site location is shown on Figure 1 -Site Location Map. The proposed construction is anticipated to consist of a single-family residence. The scope of our investigation included evaluating the subsurface conditions at the site to aid in developing foundation recommendations for the proposed construction. Site Conditions At the time of the investigation, the site was open with a general slight slope down towards the north. Vegetation consisted primarily of sparse weeds. The site was bordered to the north by Eagle Ridge Drive, to the west by a vacant lot, to the east by a residential property, and to the south by open land. Subsurface Investigation The subsurface investigation included one test pit at the site as shown on Figure 2 -Site Plan. The test pit was excavated to a depth of 8.0 feet below the existing ground surface. A typed test pit log is included in Appendix A • The test pit encountered 1.0 foot of topsoil above tan to white, dry to moist, medium dense to dense silty sand with gravel, cobble, and boulder soils to the bottom of the excavation. Groundwater was not encountered in the subsurface at the time of the investigation. Laboratory Testing Laboratory testing was conducted on samples of the native soils collected from the test pit. The testing included natural moisture content determination, grain-size analysis, Atterberg limits determination, water soluble sulfates content determination, and maximum dry density and optimum moisture content (Proctor) determination. The laboratory testing results are included in Appendix B. 178 Eagle Ridge Dr. #02453-0002 04/18 /22 \ Huddltston-Beny J,.1,io(tth,,c .•, f 1o1t1•<,I I ( The laboratory testing results indicate that the native sand soils are slightly plastic. In general, based on the Atterberg limits and our experience with similar soils in the vicinity of the subject site, the native sand soils are anticipated to be slightly collapsible. Water soluble sulfates were detected in the site soils in a concentration of 0.003%. Foundation Recommendations Based upon the results of the subsurface investigation and nature of the proposed construction, shallow foundations are generally recommended. Spread footings and monolithic (tumdown) structural slab foundations are both appropriate alternatives. However, in order to provide a uniform bearing stratum and reduce the risk of excessive differential movements, it is recommended that the foundations be constructed above a minimum of 24-inches of structural fill...,_ __________________________ _, _ ____, The native sand soils, exclusive of topsoil, are suitable for reuse as structural fill. Imported structural fill should consist of a granular, non-expansive, non-free drai11ing material approved byHBET. For spread footing foundations, the footing areas may be trenched. However, for monolithic slab foundations, the structural fill should extend across the entire building pad area to a depth of 24- inches below the tumdown edges. Structural fill should extend laterally beyond the edges of the foundations a distance equal to the thickness of structural fill for both foundation types. Prior to placement of structural fill, it is recommended that the bottom of the foundation excavation be scarified to a depth of 6 to 8 inches, moisture conditioned, and compacted to a minimum of 95% of the standard Proctor maximum dry density, within ±2% of the optimum moisture content as determined in accordance with ASTM D698. Structural fill should be moisture conditioned, placed in maximum 8-inch loose lifts , and compacted to a minimum of 95% of the standard Proctor maximum dry density for fine grained soils and 90% of the modified Proctor maximum dry density for coarse grained soils, within ±2% of the optimum moisture content as determined in accordance with ASTM D698 and D1557, respectively. Structural fill should be extended to within 0.1-feet of the bottom of the foundation. No more than 0.1-feet of gravel should be placed below the footings or tumdown edge as a leveling course. F or structura l fi ll consisting of the native soil s or imp orte d granular mat erials and fo und ati on building pad preparation as recommended, a maximum allowable bearing capacity of 1,500 psf may be used. In addition, a modulus of subgrade reaction of 150 pci may be used for structural fill consisting of the native soils and a modulus of 200 pci may be used for suitable imported structural fill. Foundations subject to frost should be at least 36 inches below the finished grade. As discussed previously, water soluble sulfates were detected in the site soils in a concentration of 0.004%. This concentration of sulfates represents a negligible degree of potential sulfate attack on concrete. However, soluble sulfate concentrations can vary widely in Western Colorado. Therefore, at a minimum, Type 1-11 sulfate resistant cement is recommended for construction at this site. Z:1200 8 ALL PROJECTS\0 2453 -T-Squared Mesa\02453-0002 178 Eogl e Ridge Drive\200 -Geo\02453--0002 LR04 I 822.doc 2 178 Eagle Ridge Dr. #02453-0002 04/18 /22 @ Huddlt~1on-Beny l 111in .-r,l11r.\fr,1 l11 ,:,I I C < Any stemwalls or retaining walls should be designed to resist lateral earth pressures. For backfill consisting of the native soils or imported granular, non-free draining, non-expansive material, we recommend that the walls be designed for an equivalent active fluid unit weight of 45 pcf in areas where no surcharge loads are present. An at-rest equivalent fluid unit weight of 65 pcf is recommended for braced walls. Lateral earth pressures should be increased as necessary to reflect any surcharge loading behind the walls. N on -Structural F loor Slab and E xterior F latwork Recommendations In order to limit the potential for excessive differential movements of slabs-on-grade it is recommended that non-structural floating floor slabs be constructed above a minimum of 18- inches of structural fill with subgrade preparation and fill placement in accordance with the Foundation Recommendations section of this report. It is recommended that exterior flatwork be constructed above a minimum of 12-inches of structural fill. Drainage Recommendation s Grading a11d drai11age are critical to tl,e l011g-ter111 performance of tl,e structure. Grading around the structure should be designed to carry precipitation and runoff away from the structure. It is recommended that the finished ground surface drop at least twelve inches within the first ten feet away from the structure. It is also recommended that landscaping within five feet of the structure include primarily desert plants with low water requirements. In addition , it is recommended that automatic irrigation, including drip lines , within ten feet of foundations be minimized. HBET recommends that surface downspout extensions be used which discharge a minimum of 15 feet from the structure or beyond the backfill zone, whichever is greater. However, if subsurface downspout drains are utilized, they should be carefully constructed of solid-wall PVC and should daylight a minimum of 15 feet from the structure. In addition, an impermeable membrane is recommended below subsurface downspout drains. Dry wells should not be used. In order to limit the potential for surface moisture to adversely impact the structure, a perimeter foundation drain is recommended. In general, the perimeter foundation drain should consist of prefabricated drain materials or a perforated pipe and gravel system with the flowline of the drain at the bottom of the foundation (at the highest point). The prefabricated drain materials or gravel should extend along basement walls to within 36-inches of the finished grade. The perimeter drain should slope at a minimum of 1.0% to daylight or to a sump with pump. The drain should also include an im permea ble mem brane at th e ba se to limit th e potential for moisture to infiltrate vertically down below the foundations. General Notes The recommendations included above are based upon the results of the subsurface investigation and on our local experience. These conclusions and recommendations are valid only for the proposed construction. Z:12008 ALL PROJECTS\02453 -T-Squared Mesa\02453--0002 I 78 Eagle Ridge Drive\200 -Geo\02453-0002 LR04 I 822.doc 3 178 Eagle Ridge Dr. #02453-0002 04/18/22 @ < Huddlt5ton-Bmy l n t i11rul11t,'-l r •1 \,,4, I I C As discussed previously, only one test pit was conducted at the site. Therefore, the precise nature and extent of subsurface variability may not become evident until construction. As discussed previously, it is recommended that HBET provide construction materials testing and engineering oversight during the entire construction process. In addition, the homeowner and any subcontractors working on the project should be provided a copy of this report and informed of the issues associated with the presence of moisture sensitive sub grade materials at this site. It is importa11t to note that the reco111mendations herein are i11te11ded to reduce the risk of structural move,nellt and/or damage, to varvi11g degrees. associated with volume cl,a,,ge of the native soils. However, HBET cannot predict long-term changes in subsurface moistul'e co11ditions and/or the precise magnitude or extent of volume change. Where sig11ifica11t increases i11 subsurface moisture occur due to poor gradirig, improper stormwater management. utility line failul'e. excess irrigatio11, or other cause, either during construction or the result of actions of the propel'tv owner. several i11c/1es of movement are possible. In addition, any failure to complv with the recom111endatio,is in this ,-eport releases H11ddleston- Berrv Engineering & Testing, LLC of anv liability with regard to the structure performance. We are pleased to be of service to your project. Please contact us if you have any questions or comments regarding the contents of this report. Respectfully Submitted: Huddleston-Berry Engineering and Testing, LLC Michael A. Berry, P.E. Vice President of Engineering Z:\2008 ALL PROJECTS\02453 . T-Squarcd Mcsa\02453-0002 178 Eagle Ridge Drive\200 • Geo\02453~002 LR04 I 822,doc 4 ) FIGURES OqPublic.net™ Garfield County, CO ...__ R470041 240707109001 BMAWILLOW PARK LLC R470033 240 718100004 DARTER LLC R084206 240718121002 Date created : 4/13/2022 Last Data Uploaded: 4/13/2022 2:20:32 AM Developed byllfL_ .... Schneirler ... , G E OSPIITI IIL. R045228 240708300185 VANDEUSEN TAMMIE NG SQUARED LLC R043105 240717213150 R045232 240708302001 R470059 240717209002 R043107 2407172151M FIGURE 1 Site Location Map OqPublic.net1 "' Garfield County, CO Date created: 4/13/2022 Last Data Uploaded: 4/13/2022 2:20:32 AM Developed byl/£ ... Schneider ... , O!.OSPIITI A L NG SQUARED LLC R042197 240717211033 FIGURE2 Site Plan APPENDIX A Typed Test Pit Log Huddleston-Berry Engineering & Testing, LLC 2789 Riverside Parkway Grand Junction, CO 81501 970-255-8005 CLIENT T-Squared Mesa , LLC PROJECT NUMBER 02453-_0_0_Q2 DATE STARTED -=3=/2=3=/2=2=-------COMPLETED _3=/=23=/2=2,___ __ EXCAVATION CONTRACTOR ....:H..:..:i....:.-R.!:.iv::..:e:::..r _________ _ EXCAVATION METHOD _T:...a.r=-ac=k"'h'""/B::.:a:..:c'--"khc:.:o:..:e'----------- I- LOGGEDBY _W=D~A ____ _ CHECKED BY ....:M.c.::Ac...::B=------ NOTES ___________________ _ J: t-~ a..i= w- 0 0.0 (.) i:c.9 a.a ~...J (!) ?,-,., .. ·" ;-.•:,: i-t ·.~ :~_ .. ,\ i)I, .,'\ i,. • ~ ·::;:·.~ ~-.-~ MATERIAL DESCRIPTION SIity Sand with Organics (TOPSOIL) TEST PIT NUMBER TP-1 PAGE 1 OF 1 PROJECT NAME _1.,_,7-"8'--'E""a:::,g""'le:....,.R.!!id~g:ce'-------------- PROJECT LOCATION Paf'achute, CO GROUND ELEVATION ____ _ TEST PIT SIZE _____ _ GROUND WATER LEVELS: AT TIME OF EXCAVATION ...,D=.z.. ___________ _ AT END OF EXCAVATION ....,D"-'-'------------- AFTER EXCAVATION _-_____________ _ w a. ~ffi wlD ...J:::i!: a. :::J :::i!:Z ~ ';ft >-0:: ~ wO 6~ u- ~ :s:~w oz3 ...J :::J <( mo> 0~ ATTERBERG I- ~ ~ wl LIMITS z w a. I-0::1-~ I- 1-.::---=-:::Jz o z w.l!l Z u 1-w Q1--1-[5X 0~ ~-:::J-9: ~I-:::J-1-_ -W 0~ o >-oz o~ cn::i~ ~o en ~ a:: :::i!:O ....1-....1 ....1 jz w 0 0 a. -z a. u:: ft\ ,<i:,t) Silty SAND with Gravels, Cobbles, and Boulders (SM), tan to white, dry to moist, medium dense to dense I-~{/:' ~: .. :o -· lti • if& 1L 1 ' 15 C) ~~ -P.JX: U) ::> ~/{ ~ i3 ,:-~, § :_~1::\ :I :,.:o , ~ ~-:/\ ~ ,o·.-.{J @ '•:>:-:: ~ 7.5 .-:c>;>·: GB-1 : Lab Classified t,l ~B 9 I 27 I 25 2 I 44 g ~ft § ;---~~~~:~6~· ··t---------=-----.,-------------l ~ Bottom of test pit at 8.0 feet. "' ~ 0 Cf) z ::; :::, ...J 0 (.) r co :c (.) 6 UJ c,.___..1--_.1.-____________________ ___JL-._--1._-L __ __l"-----1--1.._...L _ _L_L_JL_J APPENDIXB Laboratory Testing Results --=--GRAIN SIZE DISTRIBUTION @ • Huddleston-Berry Engineering & Testing, LLC 2789 Riverside Parkway GmndJunction, CO 81501 970-255-8005 - CLIENT T-Sguared Mesa, LLC PROJECT NAME 178 Eagle Ridge PROJECT NUMBER 02453-0002 PROJECT LOCATION Parachute CO U.S. SIEVE OPENING IN INCHES I U.S . SIEVE NUMBERS 1 HYDROMETER 6 4 3 2 1.5 ..1. 3/4 1/23/8 3 4 6 810 1416 20 30 40 50 60 100 140200 100 I I "'!\( I I I I I I II I I I • ; 95 I". ; 90 ~~ r---..._ 85 -i ~ 80 75 .. i • 70 :r\. II 65 : \ f-\ :c ~ (!) 60 uj -. :s: >-55 \ CD 0:: UJ 50 z u:: \: f-45 11!1 z UJ u 40 0:: UJ a.. 35 30 25 20 15 10 5 : 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS COBBLES I GRAVEL SAND I SILT OR CLAY I coarse fine coarse medium I fine I Specimen Identification Classification LL PL Pl Cc Cu • TP-1, GB-1 3/22 SIL TY SAND(SM) 27 25 2 Specimen Identification D100 D60 D30 D10 %Gravel %Sand %Silt %Clay • TP-1, GB-1 3/22 25 0.176 12.0 43.9 44.1 @ Huddleston-Berry Engineering & Testing, LLC ATTERBERG LIMITS' RESULTS 2789 Riverside Parkway Grand Junction , CO 8 150 I _ 970-255-8005 ---=--- CLIENT T-Sguared Mesa , LLC PROJECT NAME 178 Eagle Ridge PROJECT NUMBER 02453-0002 PROJECT LOCATION Parachute CO 60 _V I" @ @) 50 V p L / A s 40 / T I / C I 30 T V y I ,/ N 20 D / E X / 10 V CL-ML / @ @ • 0 0 20 40 60 80 100 LIQUID LIMIT Specimen Identification LL PL Pl #200 Classification • TP-1, GB-1 3/22 27 25 2 44 SIL TY SAND(SM) . ®Huddleston-Berry Engineering & Testing, LLC MOISTURE-DENSITY RELATIONSHIP 2789 Riverside Parkway Grand Junction, CO 81501 970-255-8005 ~ CLIENT T-Sguared Mesa , LLC PROJECT NAME 178 Eagle Ridge PROJECT NUMBER 02453-0002 PROJECT LOCATION Parachute CO 1:>U \ \ \ \ Sample Date: 3/23/2022 \ \ \ \ Sample No.: 22-0272 \ ' \ Source of Material: TP-1, GB-1 145 \ r\ \ \ ' Description of Material : SILTY SAND(SM) i\ \ \ \ \ \ \ Test Method (manual): ASTM D698A \ \ 140 \ \ \ \ ~ \ ' \ \ \ \ 135 \ ~ \ TEST RESULTS \ \ \ \ \ Maximum Dry Density 105.5 PCF \ r\ \ Optimum Water Content 18.0 % \ ' 130 \ \ \ \ [\ \ \ \ ' GRADATION RESULTS (% PASSING) \ I\. #200 #4 3/4" ' \ \ 125 \ \ .. 44 88 96 \ \. --\ 't3 \ \ ' C. \ ' \. ~-\ \ \. in '\ \ '\. ATTERBERG LIMITS z 120 UJ \ I\ \. Cl I\ \ >-I\ LL PL Pl a:: \ \. \. ---- Q 27 25 2 I\ '\ ' 115 '\ \. \. ' '\ ' Curves of 100% Saturation " " '\. for Specific Gravity Equal to: ' '\ \ " " ' 2.80 110 \. '\ ' " ' ' 2.70 \. " 'I 'I\. ' ' 2.60 I\,. 'I\.. .. 105 / ~ '\. '\. ' , , I, '\ '\. I I'\. ' '\. '\. I ' 'I\.. '\ ' I ~ I'\. 'I\.. " 100 " ... '\. " ' ..... '\. '\. ~ \. ." '\ " \.. ' " " "'!I.. ' " ' 95 '\. ' " " ' " 90 0 5 10 15 20 25 30 WATER CONTENT,%