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Home My WebLink AboutSubsoil Studyt-t ËpwCIRTH -PAWLAt( G EO'|ËCH N tCA L I lrl,rr¡,trll -l',rrr'l.rl {.ir, *r.l r¡ ¡x.rl. lu i¡.ìit"! t ¡ru¡¡tt ß,'rJ l5.T ( ilç¡trrrr.nl S¡'r'ttl,.t., t '',!,,r,¡,l,r IIt¡tlI I'l r, ¡¡tr: tlTtr' tl.l i" iQs.r l-.r..: rr¡il-*-l i.rl i.l r rtr.lil: li¡:c"ü l1l\L(, {i ':h i' rtrì F==il REGEIVED ücT 2 0 2021 GARFIELD COUNTY COMMUNITY DEVELOPMEI{T SUBSOIL STUÞY rOR FOUNDATION DESIGN PROPOSED BARN ADDITION AND RESIDENTIAL TRI.PLEX ASPEN VALLEY POLO CLUB ASPEN EQIIESTRTAN ESTATES COUNTY ROAD IOO, GAR¡IELD COUNY, COLORADO It JOBNO. lI3 459A DECEMBER 18,2013 PREPARBD FoRr DIVTDE CREEK BUILDERS ATTN: II{AXFILISS 1531COTTNTyROAD 342 SILT, COLORADO t1652 ¡l! ¡$ û l¡t qß"'"Ye[-q9Jgr-ì P¿rker ]tll"S4l"7l¡9 o Cokrr¡rclc SFrings ?19'ó11-5562 u Sih'erthotn,.' 9711-4(rtì-1989 TABLE OF CONTENTS PURPOSF AltD SCOP.E OF STUDY ..,.,.-........,.. I - PROPOSED CONSTRUCTION......... .............,,...:. ................, I - SITE C9¡IDTflONS ..,,,.............. .....-2- SUBSIDENCË POÎENTIAL..,.."....,..... ........,....,2 - FIELD Ð(PLORJq.TION..........,....;............,,.. .....- 3 - SUBSURFACE CONDITIONS.....,. FOUNDATION BEARTNG CONDrTrONS...,..."......,. .......,...- o - ÞESTGN RECCIMMËNbATrONS.................,....;......, ...........- 4 - FOUND4TIONS.......,.,..........i...........,... .-........- 4 - FLOOR SLABS .r.,...i....!!.,...,,.,...,.......,.r¡.,.,....,.,.,r.,.,, ....,..- 6 - TJNDERDRAIN SYSTEM ........,.." 6 - SUR.FACE DRAINACE ...........i..,.........,...,,...' 7 - LIMITATIONS FIGURE I - TOCATTON OF ÐßLORATORY BORINGS FIGURB2 - LOGS OF EXPTORATORY BORINGS FIGI,IRE 3 - LEGEND AND NOTES FIGURE 4 - SïVELL-CONSOTIDATION TBST RBSULTS FTCÙRE 5 . GRADATION îEST RESUTTS TABLE I- SUMMARY OF'LABORATORY TEST RESULTS PURPOSE AND SCOPE OX'üTITDY This rqport præents ttre results of a subeoil rtudy for a proposed barn addition and rosidontial tri-plex to be located at tho Aspon ValleyPolo Club, Aspen Equæhian Estates; CountyRoad 100, GarfieldCounty, Colorado. TheprojectsiteisshownonFiguro 1. The purpose of tne study was to develop recommendations for thç foundation design. Tho study was conducted in accordancs wíth our agree,ment for geotechnical engineeríng services to Divide Creek Builders dated Ðecembe¡ ll, 2013. Hepworth-Pawlak Geotechnical, Inc. proviously perfomred a prelirninary geotechnical study for the proposed development (Preshana Farms) andreported our findings uuderJob Numb,er 198 501, dated August 31, 1998. We also provided ageotechnical engineering study for a proposed connercial area on theproperty, Job Number 704'139, dnted Novçmber 30, 2004. A field explorationprognm consisting ofexploratoryborings was conducted to obtain information on the zubsurfaoe conditions. Samples of the subsoils obtained during the field explor¡tion wsre tested in the laborahry to determine their classification, comprossíbility or swell and other enghcoring characteristics. The results ofthe ñeld exploration and laboratory testing were anal¡ued to dovdop reconrmendations for foundation t¡ryes, depths and allowable pressures for the proposod building foundation. This report summarizes the data obhined durihg this study and presents our concluiions, ilosign rcconmcndatìons and other geotachnical engineeriugconsiderations based onthe proposed consftuotion ånd the sr:bzurface oonditions encountered. PROPOSED CONSTRTICTION Theproposed bam addition will be a tall one story wood frame stucture. Ground flobr will bo alab-on.grade. Orading for the shucture is aszumed to be relatively minor with cut depths betweon about 2 to 4 feet. The proposed tri-plex ¡t ill be one and two story wood ûame consüuctíon above a crawlspace. Grading for the skucturss is æsumed to be relativoly minor with cut dopths betwson about 2 to 4 feet, lVç assumo relatively líght Job No. I 13 4594 eeFtacn 2- foundation loadings, t)æical of the proposed type of consfuction. Theproposed building lo'cations are shown on Figure 1. The øristing pole bam, garage and residence wÍll be razd prior to constructíon. If buildittg loadings, location or grading plans chanp significantly from those desøibed abovg we should be notified to re.evaluate the recommend¿tions contained in this report. STTE CO¡IDITIONS Tho property has recentiy been ussd for equesfian putposes and devolopmênt haÉ consisted ofba.ms, sheds, indoor arena and outside stables and arenas. An existingpole barr¡ garage aud residence consbucted prior to the subdivisiou creation aro loc¿ted in the southeast comer of the properly, An existing stable and indoorar€na are locatcd in the southwest comer of theproperty. The properly is relatively flat with a slight slope down to tlrs west. There was nbout 4 inches of snow cover at the timo of our field invostigation. STJDSIDENCE POTENTTAL Bedrock of the Pennsylvanian age Eagle Valloy Evaporite underlies the Aspen Equeshian Estak$ zubdivision. These rocks aro a $equence ofg¡psiferous shaie, fine-grained sandstone and siltstone with somc massive beds of glrysum and limestone. Thers ie a possibility that massive gypsum doposits assooiated u¡ittr the Eaglo Valley Evaporite unde¡lie portions of thc lot. Dissolution of the gypflrm undcr cortain conditions can cãu$o sinkholes to develop and can produce arcas of localizsd subsidenco. During provious work in the area" $svoral sinkholes have been observed scattorcd tirouglrout the lower Roaring Fork River Vnlley. Sinkholes we,re not observed in the immediatc area of the subject property. No evidence of cavitie$ w¿s encountered in the zubsurface materials; howover, the exploratory borings were relatively shallow, for foundation design only. Based on ourpresont lmowledgs of the subsurface conditions at the site, it cannot be said for certain that sinlúolei will not JobNo. l13459A eëFteqrr ,3- develop. The risk of futuro ground subsidence on the proporfy throughout the servicç life of the proposed bam addition aud tri-þlex, ín our opinion, is low; howeve¡ thç owner should be made âwaro of the potenti¿l for si¡¡khole development. If firf.her iuvesfigation of possible cavities in the bedrock below the site is desíred, wo should be mntacted. ÏÏELD EXPLORATION The field orploration for the project was conduoted on December 11, 2013. Fonr exploratory borings were drilled at the'locations shown on Figure.l to evaluate the subsurface oonditions, Two borinp were drillod at the bam atldition and two bodngs in the arca of the hi-plex, Theborings we¡e advanced with 4 inch diamctor condnuous flight åugers powercd by a üuck-mounted cME-458 driil rig. Tho boringe were loggod by a rtpresentative of Hepworth-Pawlak Geofechnioal, lnc. Samples of ihe subsoils vrere taken with l% inch and 2 inch I.D. spoon sanrplers. The sannplers were driven intó the sub¡oils at iarious deptbs with blows ûom a 140 pound hammer fatling 30 ínches. This test ís similar to the standard penetration test described by ASTM Method D-t5Ù6. The poneüation resistance values are an indisation'of the relalive density or consistenoy of the subsoils. Depths at whích tho samples were taken and the penetration re$istance values are shown on tho Logs of Exploratory Borinp, Fþre 2. The samplos were retutned to our laboratory for reviEw by tbe projec{ ongìneer and testing. SUBSTIRT'ACE CONDITIONS Graphic logs of the subsurface conditions encountered at the site a¡o shown on Figuro 2, Tho subsoils conri¡t of about one to two feet of fill overlying a relatively thin layer of clay above sandy gravel witlr cobbles and small boulclers. Drilling in the dense granular soils with auger equipment wæ difficult due to the cobbles and boulders and drilling refiisal was encountercd in the deposit. JobNo. l13459A c&Ftecl"r -4- Laboratory testing performed on samples obtained ftom tho borings included natural moisture cotrtent and gradation analyses. Rasults of ¡well-consolidation testing' performed on a relativcly undisturbed drive samplg preeented on Figure 4 indicate moderats comprersibility under condítions of loadingand wetting. Rç,cults of gradation analyses performed on a small dÍameter drivo sample (minus lYz ncbftaction) of tho coarse granular subsoils are shown on Figure 5. The laboratory testÍng is summôrized in Table L No free water was çncountered in the borings at the time of drilling and the subsoils were slightly moist to moist. FOUNI}ATION BEARING COIIVI'ITIONS A pit about 4 feot deep was observed alongside the existing stable. Tho existing footing was exposed and the bottom of thc footing wao about 2 feet below srinounding grade. The zubsoils oxposed consisted of sandy'clay fill above sandy clayoverlyinggranula¡material at 3l¿¿ feet bolow grade. The proposed barn addition excavation adjacent to the oxistÌng banr should oxpose the botfom of the oxisting footings and penetrate all fill ¡r¡aterial. Tho tri-ptor fooþrint spane over tlie existing garage and a few ftçt of fill material should be expected ín this area. Atl fill aud sandy çlay soils should bo rcmoved and the excavation extended down to granular soils. DE SIGN RECOMME¡IDATIONS FOUNDATIONS Considering the subsurface conditions encountered in the exploratoryborings and the natura of the proposed oonstruction, we recommend tlre buitding be founded with spread footingn beming on the natur¿l granular soíls. Job No ll3459A c&Bteclr 5- The design and constn¡ction criteria presented below should be obseryed for a spread footing foundation system.. 1) Footings placed on the undísturbed natural granular soils should be designed for an allowable bearing prossure of 3,000 psf.The barn addition can bo founded the natural sandy clay soils and designed for a maximum soil bearingprossurs of 1,500 psf, Based on experience, wo expect settlônênt of footings desþed and constructed as discussed in this section will be about 1 inch or less. 2t The footings should have a minimum width of 16 inohes for continuous walls and 2 feet for imlated pads. 3) Bxterior footings and foolings beneath unheated areas should be provided with adequate soíl cover above their bearing olevation for ûost protection. Placement of foundations at least 36 inches below exterior grade is tlæicallywed-rn'tltir¡'area. A shallowet.fdotin¡iprbleðfeil-fr-oiñ fi'odtwith '- insulation, dosigned in accordånce with the Intemational Building Code could also be constructed. 4) Continuous foundation walls ¡hould be reinforced top and bottom to span local anomalÍes such as by assumirrg anunsupported length of at least 10 feet. Fou¡rdation walls acting as retaining skucturæ should also be desþed to rosist lateral a lateral earth prossure conesponding to an equivalent fluid unit weigþt of at least 45 po[, 5) All existing fill, topsoil; sandy clny in tho tri-plex excavation and any loose or disturbed soils should bo removed and the footing bearing level oxtended down to the retatively donse natural granular soils. The exposed soils in footing area.should thcn be moistened and compacted. If water seepage is encountered, the footing areas should be dewatered before concrete placement. 6) A representativc of the geotechrúcal engineer should observe all footing excavations príor to sonorete placemont to evaluato bearing conditions. JobNo. l13459A cåFtecn -6- FLOOR STABS The naturål on-site soils, exclusive of topsofl, are suitable to zupport lightly loaded slab- on-grade conshuctíon, To reduco the effects of some differcntial movement floor slabs should be soparatod from all bearing walls and columns with expaneion joints which allow unrestrained vortical movçmbnt. Floor slab conhol joints ehould be ueÊd to reduce damags due to shrínkage cracking, The requiremeuts for joint spacing and slab reinforcement shouldbe o$tûblished by ths designer'basod on experiÊnce and the intended slab use. A minimum 4 inch layer of free-draining gravol should be placed beneath slabs to provide a break for capillary moisture rise. This material should consist ofminus 2 ínch aggegate with at least 50% retained on the No. 4 sieve and less than 2% passing the No.200 sieve. All fill materials for support of floor slabs should be compacted to at least 95% of maximum ståndard Prostor density at a moisture contcnt near optimum. Required fill can consist ofthE on-site granular soils devoid ofvegetation, topsoil and ovçrsized rock. UNDBRDRAIN SYSTEM Allhougb fræ water was not encountered during our oxploration, it ha¡ been our orperienog ínmountainous aroas that looal perched groundwator can develop during timoa of hoavy precipitation or seæonal runoff. Frozen gpund during $pr¡ng nrnoffcan'create a perched oondition. lVe recomnend below-grade consfucfion, such as rotaining walls and øawlspaco areâs, be protected from wetting and hydrostatic pressruo buildup by an under'drain system, The drains should consist of drainpipe placed in the boftom of the watl backfill sunoundod above ile invort lsvel with fiee-draining granulãr material. Ths dlain should be placed at each levcl of excavation âtrd at least I foot below lowost adjtcent finieh gradeandslopedataminimuml%toasuitablcgravityoutlet. Free-draíninggranular mateúal usod in the undordrain systern shoulct contain less than Za/o passnglhe No; 200 Job No, 1134594 7- siove, less than 50% pæsing the No. 4 sieve and have a maxinrum size of 2 inches. The drain gravel bacldlll should be at least lVz faetdeep. SUR¡'ACE DR.A.INAGE The following drainage precautions should be observed during construction and maintained at all times ¿fter thebarn addition and ûi-plex have been completed: 1) Inundation ofths foundatÍon excavations andunderslab arcas ¡hould be avoided during consffuctior 2) Exterior backfill should be adjusted to near optimum moisflue and compactod to at loast 95% of the maximum standard Proctor density in pavement and slab areæ and to at least 90% of the maximum standard Prcctor.dçnsiþ in landscape fi€as. 3) The ground zurfacc sunoundiug the exterior of the building should be sloped to drain away from the foundation in all dirootions' lVe reoommond a minimum slope of 6 iuches in the.first I 0 feet in unpaved a¡eas and a minimum slopo of 2% rnches in the first 10 feet in paved areas' Free-draining wall backfill should be capped with about 2 feet ofthe on- ' site soils to reduce surface water infilkation' 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. LIMfTATIONS This efudyha¡ been conducted in accordsnce with generally accepted geotechnical engineeringprinciples and practices ln this area at this tìme. We make no warranty either sxpress or implied. The conclusions füd resommendations submitted in this report are based upon the data obtainod from the exploratory borings drilled at tho locations indicated on Figuro 1, tho proposed t¡rye of constx¡ction and our expedencs in the ârea. Our services do not include dctermining the præoncE prevention or possibility of mold or other bíological contamÍnants (MOBC) developing in the fiiturç. If the client is JobNo. l13459A e&Stecn 8- conc€rned about MOBC, then a professional in this special field of practice should be consulted. Our {indings include intetpolation and exkapolation of the subsurface conditions identified at the exploratory borings and variations in the subsurface conditions may not become evident until excavation is performed, If conditions encountered during conshuction åppeâr different from those described in this repoft, we should be notified so that re-evaluation of the recommendations maybe made. Tlús report has been prepared for the exclusive use by our client for design purposes. 'We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation and field services during construction to review and monitor the implementation of our recommendations, and to veriff that the tecommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications to the rccommendations præented herein, We recommend on-site observation of excavations and foundation bearing shata and testing of struetural fill by a.represerrtative of the geotechnical engineer. Respectfu lly Submitted, - PAV/LAK GEOTECHNICAL, INC. Louis E. Eller Reviewed by: Hardin, P.E. LEE//ksw Job No. 113459Â c#fracrr COUNTY ROAD lOO 6280 L--( I I PROPOSED TRI.PLEX (SHADED) BORINGs ËXISTING BARN EXISTING utoEä$ut Ëä #ã>É,EH #P< '\lErorll HEto u¡ -*-\GARAGE *-\ *_{Ílb---\-.\ I I I I t I II I I Ð(sïtNG BESIDENCË (I \*-t/ 6'e¡6 cil¡tã1-f<at ä3d8 TFQlz-.trÈ Ed Hr ıËU te, E¡Omo \-* a r I I I I I I I o IIt PROPOSED L-J BARNADDITION (sHADËD) APPROXIfì,4ATE SCALE 1o = 80' 1 EXISTING BARN EXISTING INDOOR ARENA I I 1 18 4594 LOCATION OF EXPLORATORY BORINGS Figure 1 BORING 1 ELEV,* 99.2' BORING 2 ELEV.= 97.2' BORINGS ELEV.= 6278.6' BORNq 4 ELF/.:6275.9' 0 0 416,12ß WC-18.3 DD*109 67112 WC=2,9 +4-6fl -200-7 10112 WC='|6,8 -200-56 ilï,1510 wc=7.0 -200*66 Ë 'rI.c Þ..tto 5 ï 65/12 5 ü) Ê I.c r:-(l,cl 10 10 BARN ADDITION TRI"PLEX Note: Explanation of symbols ls showrt on Figure 3. Flgure 2LOGS OF EXPLORATORY BORINGS1 13 4594 CLAY (CL); sandy, sllty, medlum stiff, molst, reddlsh brown to brown. m H n ffi F I T LEGEND: FILL; olayey silty sand and gravolwith cobbles, loose, molst, mixed browns. About 6 inúes of road base above fill at Boring 3. TOP$OIL; organlc sandy clay and silt, firrn, molst, dark brown. GRAVEL, COBBLES AND BOULDERS (GM-GP); oandy, sllghtly sllty lo slfty, {ense, molst, brown, subrounded rocke, Relatlvely undisturbed drive sarnple; 2-inoh l.D. California llner sample. Drlve sampfe; standard penetration test (SPÐ, 1 3/8 lnch f.D. sptlt spoon sample, A$TM t)-1S86. ùive sample blow count; indicatee thät 57 blows of a 140 pound hammer falling 30 lnches were Ðtt t'¿ required to drive lhe Callfornia or SFT sampler 12 fnches. Practical drllllng refusal. Where shown above bottom of log, indioates that multiþle ãttempts wêre made to advanceihe boring. NOTE$: 1, Exploratory borlngs were drllled on December 11, 2013 with 4-inch dlametèr contínuous flight powor augor. 2. Locallons of exploratory borings were measured approximately by pacing from featuree shown on the slto plan provlded. 3. Elevatlons of exploratory borlngs wore measured by instrumênt leveland refer to the Bonch Malks shown on Ëlgure I 4, the exploratory boilng locallons.and elevations should be coneldered aocuato only to thê degme lmplfed by tho method used. 6. The llnes bôtwesn matorlals shown on th6 sxploratory borlng loge rêpresênt the approxlmate boundàriss beMeen materlal typee and transitlons may bs gradual, 6. No free wat€r was €ncounter€d ln tho botlngs at the lime of drilllng. Fluotuatlon ln water level may occur wlth tlme. 7. l-aboratory Teoting Results: WC = Water Contênt (%) DD = Dry Density (pcf) +4 = Perçent retained on tha No, 4 Blêve {00 = Petcent passíng No.200síeve 113 4694 LEGEND AND NOTES Flgure 3 Moisture Content * 'lB.3 Dry Denslty : l0g $ample of: gsn6t $ltyClaY From: Borlng 1 at 2 Feet percent pcf No rnovsmenl upon,Î¡iettlng7 L \ \ ì \) o 1 s co'ø 1t, 0) o- EoO 2 g 4 5 0.1 10 100 APPLIED PRESSURE - ksf 1.0 1 13 4594 SWELL-CO NSOLI DATI ON TEST RESU LTS Figure 4 7HH r5MlN, ÌIMERÈAOINGE U.S. STANDARDSERIES OPENINGS #8 #4 Etsil 314'. 'l 1t2', 3'| 5'6' s 100 00 Ê0 70 00 60 4A 30 20 10 ô H4û RF- l¡JÉ, t- 60zIÊ,l!(L60 oz6ln 0- þzh,oË. l¡J0- 0 .001 ,002 ,006 .009 .01Ð .0ft7 ,074 .160 .000 t.18 U.36 4,7ı 37,ı DIAMETËR OF FARTICLES lN lvlltl-MffERS ct¡Yï0tlr coÐ$e GRAVËL 63 %SAND 80 o/o SILTANDCIAY 7 % LIOUÍD UMIÏ %PI.A$TICITY INDEX IO FROM; Borlng 2 al?lzFeelSAMPLE OFr Sllgrhtly Sllty Sandy Gravol Figure 51 13 4594 GRADATION TEST RESULTS H EPWORTH-PAWIAK GEOTECÏ NICAL, INC. TABLE 1 SUMMARY OF I.ABORATORY TEST RESULTS Job No. 113 4594 SAMPIE fI:ÀTlrlf NANRAL üOIsruRE CO'{TENT (v^\ NATURAL DRY DENSITY fEdl GRÁDAÎIÍ'I{PERGI{1 PASS¡NG ùp.200 SIEI'E ÀTTËNI UMIIS t¡¡CO¡,¡FINED coilPRESS¡ìÆ STRENGTH tp_qn SOIL OR BEDROCKTYPEBOR¡NG DEPIH tfrl GRAì/EL (%) SAND (%) UQUIÞts4Í lvâl Pt¡sfrc ¡NDÞ( I 2 18.3 109 Sandy Silty Ctay 2 21t2 2.9 63 30 7 Süehüy Silty Sady Gravel 3 I 16.8 56 SiltySaldy Clay -Fill 4 1 7,0 66 Sandy Silty Clay