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HomeMy WebLinkAboutSubsoils Report for Foundation DesignHrrddleston*Ber:ry 2789 Riverside Parkway Crand .lunction, Colorado 8 I 50 I Phone: 970-255-8005 I n fb@huddlestonbcrry.corr! rrri;1r'rrirt: ,.\ l*:,tllt,.', I 1 I' October 8,2024 Project#0291 l-0001 Julio Moreno 4406 County l{oad 331 Silt, Colorado 81652 Subject:Geotechnical Investigation 44 Roan Creek Place Parachute, Colorado Dear Mr. Moreno, This letter presents the results of a geotechnical investigation conducted by Huddleston-Berry Engineering & Testing,LLC (FIBE'I-) for 44 Roan Creek Place in Parachute, Colorado. 'fhe site location is shown on Figure I - Site Location Map. 'fhe proposed constructior-r is anticipated to consist of a single-family residerrce. 'fhe scope of our investigation included evaluating the subsurf-ace conditions at the site to aid in developing foundation recommendations for the proposed constructiot't. Site Conditions At the time of the investigation, the site was open and generally sloped gently to the west. Vegetation consisted of grasses and weeds. 'fhe site was bordered to the north by an existing residence and vacant lot" to the south by l{oan Creek Place, to the west by an existing residence, ar,d to the east by a vacant lot. Subsurface Investigation 'Ihe subsurface investigation included two test pits at the site as shown on Figure 2 -- Site Plan. The test pits were excavated to a depth of 8.0 feet below the existing ground surface. 'fyped test pit logs are included in Appendix A. As indicated ori the logs, the subsurl'ace conditions were consistent. T'he test pits encountered 0.5 feet of topsoil above tan, moist, stilT silt soils to the bottoms of the excavations. Groundwater was not encountered in the subsurface at the time of the investigation. Laboratory Testing l,aboratory testing was conducted on samples of the native soils collected from the test pits. The testing included grain-size analysis, Atterberg lirnits determination, natural moisture content and density determination, swell/corrsolidation testing. and maximum dry density and optimum moisture content (Proctor) detcrminatior"r. J'he laboratory testir"rg results are included in Appendix B. 'I'he laboratory testing results indicate that the native silt soils are slightly plastic. ln addition, the native soils were shown to be slightly collapsible, with up to approximately l.loh collapse measured in the laboratory. ea S. .\) a\ N 44 l{oan Cleek Placc #029t l-000t t0/08/24 Foundation Recommendations l lu rtdh'ston' Ilur1. 1,.;...: .,.. tJ.:. l)t Based upon the results of the subsurface investigation and nature of the proposed construction, shallow foundations are generally recommended. Spread footings and monolithic (turndown) structural slab foundations are both appropriate alternatives. However, as discussed previously, the native soils are slightly collapsible. Therefore, in order to provide a uniform bearing stratum and reduce the risk of excessive differential movements, it is recommer-rded that the foundations be constructed above a minimum of 24-incl-res of structural fill. The native silt soils, exclusive of topsoil, are suitable for reuse as structural fill. Imported structural fill should consist of a granular, non-expansive, non-free drsining material with greater than 10% passing the #200 sieve ar-rd Liquid Limit of less than 30. However, all proposed irnported structural fill materials should be approved by HBET. For spread footir-rg fbundations, the fboting areas may be trenched. I{owever, for monolithic slab foundations, the structural fill should extend across the entire building pad area to a depth of 24- inches below the turndown 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 bottoms of the foundation excavations be scarified to a depth of 6 to 8-inches, moisture conditioned, and re-compacted to a mininrum of 95o/o of the standard Proctor maximum dry density, within .E2o/o of the optimum moisture content as determined in accordance with ASI'M D698. Structural fill should be moisture conditioned, placed in maxirnurn 8-inch loose lifts, and compacted to a minimum of 95o/o of the standard Proctor maximum dry density lilr fine grained soils or modified Proctor nraximum dry density for coarse grained soils, within*2o/o of the optirnum moisture content as determined in accordance with ASTM D698 or Dl557C, respectively. Structural fill should be extended to within 0.1-feet of the bottorr of the foundation. No more than 0.1-feet of gravel should be placed below the footirrgs or turndown edge as a leveling coLlrse. F-or structural fill consisting of the native soils or imported granular materials, and foundation building pad preparation as recommended, a ntaximum 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 rnay be used for suitable imported structural fill. lroundations sr"rbject to frost shor-rld be at least 36 inches below the finished grade. Water soluble sulfates are conmon to the soils in Westem Colorado. T'herefore, at a minimum, cement adequate for Sulfate F:xposure Class S I is recommended for construction at this site. Any stemwalls or retaining walls should be designed to resist lateral earlh 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 lbr braced walls. L,ateral earth pressures should be increased as necessary to reflect any surcharge loading behind the walls. 2Z:\2008 ALI- PI{OJECI'S\0?91 I - Julio Vloreno\o291 l'0001 44 Roar Creek I'lace\200 - Ceo\0291 l-0001 l-R10082.1.doc 44 [{oan Creek Place #029r r-0001 t0/08/24 I I u rl1 I csrct-11 urty Non-Structural Floor Slab and Exterior F'latwork Recommendations ln order to limit the potential fbr excessive differential movements of slabs-on-grade it is recommended that non-structural floating floor slabs be constructed above a minimum of l8- inches of structural fill with subgrade preparation ar-rd fill placement in accordance with the Iioundation Recommendations section of this report. It is recclmmended that exterior flatwork be constructed above a minimunl of l2-inches of structural fill. Drainage Recommendations Gradi nnd drain are criticrtl to the Grading arourrd the structure sl'rould be designed to carry precipitation and runofT away from the structure. It is recotnmended that the finished ground surface drop at least twelve inches within the first ten feet away fiom the structure. It is also recommended that landscaping within five feet of the structure include primarily deserl plants with low water requirements. In addition, it is recommended that automatic irrigation, including drip lir"res, within ten feet of foundations be minimized. IlllEl' recommends that surl-ace downspourt extensions be used which discharge a minimurn of 15 f-eet h'om 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 o1' 15 feet from the structure. In addition, an impermeable membrane is recommended below subsurface downspout drains. Dry wells should not be used. General Notes The recommendations inclr"rded above are based upon the results of the subsurface investigation and on our local experierrce. 'l'hese conclusions and recomrnendatiorrs are valid only lor the proposed construction. As discussed previously, the subsurface conditions encountered in the test pits were consistent. However, the precise nature and extent of subsurface variability may not become evident until construction. As a result, it is recommended that HBET provide construction materials testing and engineering oversight during tl.re entire construction process. In addition, the builder and any subcontractors working on the pro.iect should be provided a copy of this report and informed of the issues associated with the presence of moisture sensitive subgrade materials at this site, It is imnortnnl lo nole tltot the recommen dntions lterein ore intended to redace the ri.sk of structural movement and/or damose. to varvin degrees. associated witlt volume chanse of tlte native soils. However. F'IIIF:T' cannot lons-term cltanses in subsurface moisture conditions and/or tlte precise magnitude or extent of volume cltange. llhere sienificant increoses in suhsurface moisture occur to Door crarlins. imnroner stormwater ntonospmpnl-u tiliht line fuilure. excess irri{!fltion. or other cuuse-r durins construction or tlte result of actious of the nronertv . several incltes of movement are nossihle.In uddilion. nnv to comnlv with tlte recommendations in tltis releases Huddleston- Rprrv Ensinpprins &pf lino. IICnfnnt ili.tv witlt regrnrd to the str uclurp nerfnrmnnap Zrl00llAl.l.I)l{O.llr(15\0191I'.lrrlioillorerrr\o2q1l-i)00114 ltoan('ree}iI'lacc\:00-C()\0lql1.0001 t.Rl008:4doc 1J 44 l{oan Cleek Placc #0291 l-000r t0t08124 rdge\q$l I'luddl*.{on-lhrr} Ir.i;ir....rL l, r' I I Ii 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 repofi. Respectful ly Submitted : Huddleston-Berry Engineering and T'esting, L,LC Michael A. Berry, P.E. Vice President of Engineering ,i U IU /0s/ I \?008 r\l-1. PIiO.lll( ls\o:ql I -Julio illorcno\f)li)l l-00()l -l.l li.oan ('reck l)lace\200- Ceo\o2q1 lJ)()01 l.Rl(X)sll doc 4 frlqPublic,net ' Garfreld County, CO li\ '"1 .F I. l,f \:, I l:,.I x (j i tt 240 a I ,t -I R .i n..!,' USEN. , naio 2407.CI71 09001 [)atc crcatecl: 9 /9 / 2O?.4 L ast [)ata [Jploadcd: 9/9/2024 2:09:59 AM r)evr: I o pccl ou frll },,*l.lp;# gl, #)qPuhlic'net"' Garfi eld County, Co Datc created: 9 /9 /202.4 [.ast [)ata Upload ed: 9 / 9 / 2024 2:O9:59 AM Deverooed bv(;! p,.Xrlg'df l GEOTECH tsri COLUMNS 0291 1-0001 44 ROAN C P LAB GDT 10/8/24 !vo(- mo-lzc u, mv or mz-{ LC o o o fo C> NJ CO c)c)o >J-- -= ,i1=F (u= d a-- - = uC C-w =o!-o;q v r:r @:c: G,'7 ='cX =.- R" j o' =. ; a-a 'onoC- moiroo Ioz nD o)oJc .o oo r0voC- moiz =m 5s no 0) f, o oox !doo { rn @-{.It {zc =TD mv -{T'I.A T o m o-T1 zo-lm(t, rmoxooR?o4 -2g i=mmo-{Ioo mxo -{ozoozin o{on =@q- o) lo o Im @i nImo (o o N) 5-t tr)oxJ 0)o5J ooI moxmo ID @ oo =!rmim (o o t\)s o-v o ns=E 8eH* sSXPdiir ,ot,12 onocz U mrm -t o2 o ?oa -lmaI 1' -tINm I O DEPTH (ft) GRAPHIC LOG 9. f-i =.J (o 0)l oa -to!a ar- --l mvtr o mao4TI z SAMPLE TYPE NUMBER RECOVERY % (ROD) BLOW COUNTS (N VALUE) POCKET PEN (tsf) DRY UNIT WT (pc0 MOISTURE coNTENT (%) -.tr --l =B-l@amv FINES CONTENT ("/") LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX N)('' t: j-- . lst t4 @ .irog o 0) @a o'o- CN-i rv 0) -l 3 a'!* a x o (0 N) () {o -t -oE s N) N N)o N) @ ! @o o 3 (Da E 0) I (D GEOTiCii Bf i COLUMNS 029'1 i -0001 4a CR=:K PLACE GPJ G|NT US LAB.GDT i0/8/24 !7o(- mo-lzc =ID mn oN(o o o C)tr mz -l Lc o =o OANT q=-.- *f @ o ua cw =oo vx-!r -..<0a;k;oii =. 0a ts -l G :f' 0c--o !no(- moi,-oo Ioz l-o lo) loilo tc lo L T7oc moiz =m 55 7 0) f o oF ! 0) o -{m @+ I' -{zc =tr rnn -{T'IN ! o m o-Tt zo -.1ttt(t rooo m E im mxo Ioz =m-lIoI --1 0)o5 f @ 0)ox foo ITlXo Ioz()oz-i7) oion =oq-, o) fo o -tm @i vImo (o o N)5 o moxmI E oo =!r mi mo o N 5 ono nE=; 8qsi*sSxpdiin r95'12 noCzg mrm -{oz o a O e -imo-i!-t(t, Nm o O DEPTH (ft) GRAPHIC LOG -{ vtr U @o7 !--l z SAMPLE TYPE NUMBER RECOVERY % (R0D) BLOW COUNTS (N VALUE) POCKET PEN (tsf) DRY UNIT WT (pcf) MOISTURE coNTENr (%) -tr-l =jj--{ @amno FiNES CONTENT ("k) LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX -{ Lt'N(t ':. j-. '- l<- (, r-i € J {o o) J o'a I ! Ir ari 3 o) -l 3o. a:' a @o 3 o oa E D b oo N o l-rlq m -)@f, F. 7o Io ulo _lc UJ Ltlftoz o(l ooo No UJ N @ z aE(, I Iuddleston-lJerry Lng,irreelirrg &'l'esting. LLC 2789 I{iverside l)alku'a,r, Crarrd .lunction. CO 81501 970-2s5-8005 GRAIN SIZE DISTRIBUTION CLIENT Julio Moreno PROJECT NAME 44 Roan Creek Place PROJECT NUMBER 02911-OOO1 PROJECT LOCATION Parachute, CO U.S. SIEVE OPENING IN INCHES6 4 3 21.5 1314 112 I U.S. SIEVE NUMBERS HYDROMETER 3 6 14 20 30 40 50 60 100140200 FT C' tu = cnt tuz tr Fz IU O v. tud 100 95 90 B5 BO 75 70 65 60 qc 50 45 40 te JU 25 20 15 '10 q 0 100 '10 1 GRAIN SIZE IN MILLIMETERS 0.1 0.01 0,001 GRAVEL SANDCOBBLES fine fine SILT OR CLAY coarse medium Specimen ldentification Classification LL PL PI Cc Cu o TP-l, GB-1 9/10 stL ML)22 20 2 I 'tY \ coa rse Specimen ldentification D'100 9.5 D60 D30 D10 %Gravel 0.2 %Sand %sitt %Clay o TP-1, GB-1 9/10 12.9 86.9 Huddleston-Berry Engineerirrg &'lesting. LLC 2789 I{ivelside Parkrvay Grand Junction. CO 81501 970-2.s5-8005 ATTERBERG LIMITS' RESULTS CLIENT Julio Moreno PROJECT NAME 44 Roan Creek Place PROJECT NUMBER 0291 1-OOO1 PROJECT LOCATION Parachute, CO P L S T I c I T I N D E X 50 40 30 20 10 CL.ML 0 O 0 20 40 60 LIQUID LIMIT 80 1 Speci men ldentification LL PL PI #200 Classification o TP-l, GB-1 9/10 22 20 2 87 srLT(ML) !o t-r)o m -,a: l-2 o Io trio J Iv UJl! IY Oz ott No ') otr LI' mcl UIt-l- tszo o(, ulO _,o UJ!J(f O z ou lluddleston-Berry E,ngineering &'1-esting. l,LC 2789 Riverside Parkrvay Grand.lunction, CO 81501 970-2ss-8005 CONSOLIDATION TEST CLIENT Julio Moreno PROJECT NAME 44 Roan Creek Place PROJECT NUMBER PROJECT LOCATION Specimen ldentification Ta MC% o 2.0TP-1 92 5 0 0.5 '1.0 '1.5 2.0 s 2 atF U) 2.5 3.0 3.5 4.0 4.5 5.0 5.5 100 1,000 10,000 STRESS, psf ( \ \ \ \ \ I \ \ \ \ \ I ) Classification o F-oq m J af l-zo I(, t!() _)tr V lrJtlx() z ot: oo o 2ItsO c o() I Iuddlcston-llclr';' Eng.inecling & -l'csting. l-t,C 2-7{19 Iliverside l)arkrvay Crand .lunction. CO 81501 970-255-8005 PROJECT LOCATION Parachute, CO MOISTURE.DENSITY RELATIONSHI P PROJECT NUMBER 02911-OOO1 PROJECT NAME 44 p.oAn Creek PlaceCLIENT Julio Moreno ,Ul \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ /\ \/ \// /// / Sample Date: Sample No.: Source of Material. Description of Material st10t2024 24-0609 145 TP-1 SILT(ML) Test Method (manual)ASTM D698A 140 135 TEST RESULTS Maximum Dry Density '!lg:5 PcF Optimum Water Content .-j19 Yo 130 GRADATTON RESULTS (% PASSING) #200 #4 314" 87 100 100125 o tFaz tuo to ATTERBERG LIMITS 1 20 LL PL PI 22 20 2 115 Curves of 100% Saturation for Specific Gravity Equal to 110 2.80 2.70 2.60 105 100 95 5 15 WATER CONTENT, % 90 0 10 20 25 30