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Home My WebLink AboutSoil & Foundation Investigation 06.29.2022LKP Engineeringo Inc. CIVIL/GEOTECHNICAL SOIL AND FOUNDATION INVESTIGATION FOR A PROPOSED RESIDENCE LOT 680 LOS AMIGOS RANCH FILING 5, PHASE 2 683 MONARCII ROAD GLENWOOD SPRINGS GARFIELD COUNTY, COLORADO PROJECT NO. 22-3628 JUNE 29,2022 PREPARED FOR: STEVEN KUSCHNER P.O. BOX 3484 BASALT, CO 81621-3484 P.O. Box 724,Eugle, CO 81631 Tel. (970) 390-0307 wwrv.LKPEngineering.com TABLE OF CONTENTS EXECUTTVE SUMMARY SCOPE OF STUDY SITE DESCRIPTION PROPOSED CONSTRUCTION...... FIELD INVESTIGATION SUBSURFACE SOIL AND GROUNDWATER CONDITION FOI.INDATION RECOMMENDATIONS SLAB CONSTRUCTION RETAINING WALLS. TINDERDRAIN SYSTEM SITE GRADING AND DRAINAGE LAWN rRRrGATION....................... LIMITATION FTGURES LOCATION SUBSURFACE EXPLORATION LOGS GRAIN SIZE DISTRIBUTION PERIMETER DRAIN DETAIL. STRUCTURAL FILL V/ITH GEOGRID 2 2 2 5 tJ 3 4 5 5 6 6 7 n .DRA\MING NO. 1 ,FIGURENO's 1-2 .....FIGURE NO's 3 .....FIGURE NO. 4 ,...FIGURE NO. 5 LKP Engineering,Inc. EXECUTIVE SUMMARY The proposed resiclence should be supported with conventionai type spread footings, designed for an allowatrle soil bearing pressure of 2000 psf. They should construct the footings on the undisturbed silty, sandy clay with basalt rocks or structural fill with geogrid. See Foundation Recommendations. SCOPE OF STUDY This report presents the results of a subsurface Soil and Foundation Investigation f'or a proposed resiclence to be constructed on Lot 68, Los Amigos Ranch Subdivision, Filing 5, Phase 2,683 Monarch Road, Glenwood Spdngs, Garfìeld Count5r, Colorado. The purpose of the subsurface soil and foundation investigation was to detennine the engineeriug characteristics of the foundation soil and to provide recomtnendations for the foundation design, grading, and drainage. Geologic hazard sîuclies \are oulside of our scope of sen'íces' SITE DESCRIPTION Lot 68, Lot 68, Los Amigos Ranch Subclivision Filing 5, Phase 2,683 Monarch Road, Glenwood Springs, Garfield County, Colorado is 9.489 acres lot and it is located at the end of Monarch Road, off of EIk Springs Drive off of CMC Road, on the north side of Highway 82, Glenwood Springs, Garfield County, Colorado. Vegetation within the proposed building site consisted of grass, juniper trees, and sage brush. The topography was moderate with average slopes from about 7 percent. Drainage is to the southwest. To west, north and east the property is LKP Engineering,Inc. I surrounded by HOA parccls. To the southeast ârld southwesl are existing lesidenue. To the soutlr are two vacant lots. Lot 68 was also vacant. PROPOSED CONSTRUCTION At the time of the soil and foundation investigation, architectural plans have not been developed yet. We have assumed that the proposed residence will be two story. wood frame oonstruction otl a concrete foundation, with an attached garage. We anticipate loads to be light, typical of residential construction. If tire finalizecl plans differ significantly from the above understanding, they shoulcl notiSr us to reevaluate the recorrunentlations of this repofi. FIELD INVESTIGATION The f'reld investigation, conducted on June 23,2022. consisted of excavating, logging and sampling two test pits. The test pits were dug by Ryan Ivy with a l)eere 60G trackloe. Approximate locations of the test pits are shown on Drawing No. 1. We show the soil profile of the test pits on the Subsurface Exploration Logs, Figure No's 1 and?. Soil samples for laboratory soil analysis and observation were not taken due to the shallow refusal on basalt cobbles and boulders, SIJBSURFACE SOIL AND GROUNDWATER CONDITION The soil profrles encountered in the tu¡o test pits were unifonn, consisting of about 1.5 feet of topsoil over whitish, calcarer¡us. gypsiferous. silty. sandy clay rvith basalt rocks of gravel to cobblcs and boulder size, cemented, to the maximum de¡rth ex¡r1,rred of 5 and 2.5 feet respectively, wlrere practical trackhoe refusal was encountered nn the basalt boulders. Grm¡nd LKP Engineering,Inc. 4 water was not encormtered in the test pits FOUNDATION RECOMMENDATIONS The proposed residence shoulcl be supportecl rvith conventional type spread footings, designed for an allowable soil bearing pressure of 2000 psf. They shoulcl construct the footings on the undisturbed silty-sandy clay with basalt gravel, cobbles and boulders. Frorn previous experience with similar soils, it is very likely that excavation of the large basalt rocks to level the foundation excavation for the construction of the footings, can leave large voids and nneven subgrade. If the thickness of the leveling, structural fill is more than 6 to 8 inches, sfiuctural fill improved with Tensar geogrid, as shown on the attached tletail, tigure number 4, will be implemented, The cornpletedfoundation excava.tic¡n nutst be observecl and tested by the wdersigrced engineer to verifu that the soíl condittons enc.ountered during construcliot't ere as ttntícipated in lhis report. We recomnend a minimum width of 16 inches for the continuous footings and 2 feet for the isolated footing pads. Continuous fonndation walls should be reinforced top and bottom t<r span an unsupported length ofat least 10 feet. The proposecl foundation should be set at a minimum clepth of four feet belorv the finished grade or at the minimun depth required by the local building cotle. The forindation excavation should be free from excavation spoils, frost, organics and standing water. We reconrmend proof-rolling of the foundation excavation. Soft spots detected during the proot: rolling, should be removed by overexcavation, Any overexcavation wjthin the proposed fourrdation shoulcl be bac.kfilled, in I inc.hes loose level lifts and compacted to l00Ya r:f the rnaxirnum dry density and within 2 percent of the optirnum rnoisture content as detennined in a laboratory frorn a Standarcl Proctor test (ASTM D-698). A structural fill, placed under footings should be tested by a qualified professional. LKP Engineering,Inc 5 SLAB CONSTRUCTION The natural on-site soils, exclusive of topsoìl and organics. are suitable to support lightly loaded slab-on-gratle construc'.tion. The subgrade for the slab-on-grade construction shoultl be proof cotnpacted to detect ancl remove soft spots. They shoulcl backfill overexcavated soft spots and other trndetslab fill with the on-site soil, free from topsoil ancl organics, or other suitable material, compacted to a minimum of 95 percent of the maximum standard Proctor density (ASTM D-698). Suitable material should be free from topsoil, organics and rock fragments greater than 3 inches. If during excavøtion.fbr the slab-on-grade similar conditions, øs described in the aboveþundation recomntendation.s section, with large voids o¡'uneven surface are created, strucîural.fìll çs-desu'ibe ubotte and as showtt on the Structural.fill with geogríd detail, figure nLtmber 1 yvill be used. The concrete slab should be constructed over a 4-inch layer of clean gravel consisting of -314-inch gravel u'ith at least 50% retained on the No. 4 sieve and less than 3 percent passing the No. 200 sieve. They should reinforce the concrete slab-on-grade and score conh"ol joints according to the Ame¡ican Concrete Institute requirements and per the recomrnendations of the designer to recluce damage due to shrinkage. The concrete slab shoulcl be separatecl from the foundation walls and columns wlth expansion joints to allow for indepenclent movement rvithout causing damage. RBTAINING WALLS Founclation walls retaining earth and rctaining struclures that are laterally supported should be designecl to resist an equivalent fluid densilv of 60 pcf for an "at-rest" condition. Laterally unrestrained structures, retaining the on-site earth, should be designed to resist an equivalent fluici density of 40 pcf for the "active" Ça,se. LKP Engineering,Inc. 6 The above design recommendations assume drained backfill conditions and a horizontal backfîIl surface. Surcharge loading due to adjacent structures, weight of temporary stored corrstruction rnaterials and equipment, inclined backfill and hydrostatic pressure due to undrained backfîll should be inr:orporated in the clesign. They should try to prevent the buildup of hydrostatic pressure behind the retaining wall. Passive earth pressure of360 psfcan be used lor the lateral pressure against the sides of the footings. Resistance to sliding at the bottom of the footings can be calculated based on a coeffîcient of friction of 0.5. Undisturbed soil or a stnlctural fill cornpacted to 100 percent of the maximurn dry density and r.vithin 2 percent of the optimum moistrue content will be used to resist lateral loacls at the sides of the footirrgs. UI\DERDRAIN SYSTEM To reduce the risk of surface water infiltrating the foundation subsoil. we recommend installation of a f'oundation perimeter drain (see Figure No. 4). The f-oundation perimeter drain should consist of a 4-inch diameter, perforated pipe, sloped to a suitable gravity outlet, at a 7 4 inch per foot for flexible or at a 1i8 of an inch for rigid pipe. The bottom of the trench ad-iacent to the footing shoulcl be lined with a polyetþlene moisture barrier glued to the foundation wall. The drain pipe should be covered with a minirnum of 6 inches of -314-inch fi'ee-draining granular material. Geotextile (Mirafi l40N or equivalent) should be used to cover the free- draining gravel to prevent siltation and cloggilrg of the drain. The backfill above the drain should be granular rnaterial to within 2 feet of the ground surfãce to prevent a buildup of hydrostatic pfessure. SITE GRADING AND DRAINAGE The follorving recommendations are general. Exterior backfill should be compacted at or near the optirnum moisture content to at least 95o/o aTthe maxitnum standard Proctor density under pavement, sidewalk and patio areas and to at least 90% of the maximum standard Proctor LKP Engineering,Inc 7 clcnsity uucler lanclscaped areas. They should use mec.harúr:al methods of rompaction. Do not puddle the foundation excavation. The site sunounding the building structure should slope away from the builcling in all directions. A minimum of I 2 inches in the first l0 feet is recommended in unpaved areas, and tlu'ee inches in the first 10 feet in paved areas. The top of the granular foundation backfill should be coverecl with a minimum of I foot of relatively impervious fill to reduce the potential of surface water infiltrating the foundation subsoils. Surface water naturally dtaining toward the proposed builcling site should be diverted arouud and away from it by means of drainage swales or other approved methods. The roof drains arrd rJownspouts should extend and discharge beyond the limits of the backfill. LAWN IRRIGATION It is not recommended to introduce excess water to the foundation soils by installirg sprinkler systems next to the building. The installation of the sprinkler heads should ensure that the spray from the heads will not fall within 10 feet of foundation walls. porches or patio slalrs. Lawn inigation must be controlled. LIMITATION This report has been prepared according to locally accepted Professional Geotechnical Engineering standards for similar methods of testing ancl soil conditions at this time. The type of soil testing was selectecl by the owner and general contractor as the preferred rnethod for the soil and foundation investigation over a soil and f'oundation investigation with a drill rig. There is uo ofher warrc¿nty either expressed or implied. The findings and rccornmendations of this report ale based on field exploration, laboratory testing of samples ohtained at the specific locations shown on the Location Sketch, Drawing No.I and on assumptions stated in the report. Soil conditions at other locations may vary, which ma]¡ not become evident until the foundation excavation is completed. If soil or LKP Engineering,Inc. 8 ,s"-.$,i?ffi,'#ffi øÌà:iiï;i:Y " Luiza Petrovska, PE water conditions seem different from those described in this report, we should be contacfed immediately to reevaluate the recommendations of this report. We are not responsible for technical interpretation by others of the data presented in this report. This report lras been prepared t'or the exclusive use of Steven Kuscl'tner, for the specific application to the proposed residence on Lot 68, Los Amigos Ranch Subdivision, Filing 5, Phase 2,683 Monarch Road. Glenwoocl Springs, Glenwood Springs, Carfield County, Colorado. Sincerely, LKP ENGINEERINGO NC' J:\ WP X4-LKP\ 2A22\22-3 628CLAY-SAND-GRAV-BASALT-PIIS.DOCX LKP Engineering,Inc NOTE: THE LOCATION OF THE TEST PITS IS APPROX¡MATE, IT IS NOT BASED ON A SURVEY LKP CIVIL/GEOTECHNICAL Engineering, fnc. P.O. Box 724, Eogle, CO 81631 Iel (970) 390-0507 www.LKPEnglnèerlng.com LOCATION SKETCH LOT 68, LOS AMIGOS RANCH, FILING 2, PHASE 2 683 MONARCH ROAD PN 239305107032 GARFIELD COUNTY, COLORADO PROJÈC I NO: 22-3628 scALEi -1"=1oo' DRAWING NO.: I DA'IE OBSERVED: JUNE 23, 2422 ELEVAÏ1ON: Test Pit f 1 ÐEP7H FEET s Y M B o L s' A M P L E ÐESCRIPNON OF MATERIAL ANÐ SAMPLE LOCANON LABARATORY TEST RESULTS REMARKS 5 _10 _15 20 À M ffi I Topsoil Blocky, sîlty-sondy clay over whitish, calcoreous, silty, cloyey, sondy, grovelly matrix with basolt cobbles and boulders over brown, silty, slightly cloyey, grovelly sand wîth basalt cobbles and boulders MC=|2 Z -200:11.6%*4:35.8% Refusal at 5 feet on basalt boulders Graund liloter Encountered I,EGEND: Br ÐÐ MC - 2-inch O.D. Cotífornío Liner Somple -200 - Eulk Somple - Noturol Dry Darcity (pcf) - Noturql Moisture Content - Percent Passìng No. 200 - Llquld Lìmit - Plosticíty lndex - Ground water (t€) Sieve LL PI cw tKP ENGINEERING, INC.SUBSURFACE UXPLORATION LOG PRO,EC| tto,:22-3628 IFIA,tff ,/lr: DATE OBSER\ED: JUNE 23,2022 ELEVATI0NT Test Pit f 2 DEPTH FEEî s Y MI o L s A M P L E DESCRPNON OF MATERIAL AND SAMPLE LACANON LABORATORY TEST RESU¿Is REMARKS 5 _10 -15 _20 È-.ó\\l; 7*ÉÈ Topsoíl owr whítish, colcøreoua, sílty, clo¡æy, sond¡+ gravetly matrix wÍth bosdlt cobbles (weathered bedrock) Refusal at 2.5 feet on basalt bautders Ground Water Encountered I,EGEND: tr - 2-lnch 0.4. Califomia Liner SompleI - Eulk SompleDD - Noturol Dry Density (pcf) MC - Noturol Moisture Content (%) -200 - Percant Paselng No. 2O0 SieveU - Liquíd LìmitPl - Plosticíty lndexeW - Ground water tKP ENGINEERING, INC.SUBSURFACE EI(PTORATION IOG ffi¡rur rYa,.22-3628 FEIE 'YA.'2 rsroìo$sìI$=IñÞlt,üaeIP("4FRON: Test Pit I at 4 feetus srAIØAþ s¡nÃ æÐln6 ûr, úto6ê 1 t 2rv. , r.U.S SlA¡øAfu gEIÃ'WNÆRSù.t J 1 C EIO ntî n &)¿rOfl mrOOr,lOnOH'TWEFo908070I3eoos$-o€¡osS¡o2Ato,a20JOIo-$50ðüq609F70s6090oloo5ootoo 50to5I 0.5a1 0.05o.oaîo.oolSand: 5262Flnes lî.61\\\\\\\Sllt * ClaytundfrnemcdlumcaanseGravtglfrtecoargaCobbteellolsture Co¡ztqt: 12t&avel: 35.6XDcscríptían: S'tlty dlghtly damy, grovdly sand t FOONNG Þ '.ô<..!Þ:{È Þ< ñ\ "Q"fNt-\ AWAY FROM BUILDING R BACKFILL WITH A MINIMUM OF ONE FOOT OF RELATIVELY IMPERVIOUS SOIL rLTER FABRtt (MtRAF| ,I4ON OR EOUIVALENT) 3/4.INCH DIAMETER, COARSË, CLEAN CRUSH ROCK 30 MIL MINIMUM THICKNESS,NCH DIAMËTER PERFORATED PIPE SLOPED TOPLASTIC LINER, GLUED TO A DAYLIGHT LOCATION AWAY FROM THE FOUNDATION AT 1/4-INCH PER FOOT FOR FLEXIBLE AND 1/8-INCH MINIIIIUM FOR RIGID PIPE FOUNDATION WALL cwILlcEoTECEIUCAL Engineering, Inc. P.O. Box 724, Eagle, CO 81031 Tel (970) 390-0307 www.Ll(PEng¡nce¡ing.com LKP PERTMETER DRAIN LOT 68, LOS AMIGOS RANCH, FILING 2, PHASE 2 683 MONARCH ROAD PN 239305107032 GARFIELD CÔUNTY, COLORADO 22-3628 scALE: N.T.s. 4 NGURE NO.: OVEREXCAVATION.STRUCÏU RAL FI LL AND GEOGRID N.T.S, MINUS 3/4-INCH CLEAN CRUSH ROCK {for under slab on grade 5' min 8" TriAx UNDISTURBED G TXl50 US 3-INCH ROAD BASE OR OTHER SUITABLE STRUCTURAL FILL APPROVED BY THE ENGINEER NOTË: 't. 2. 3. 4. Ã o. EXCAVATE THE TOPSOIL AND OTHER UNSUIÏABLE SOIL BACKFILL WITH 6-INCHES OF STRUCTURAL FILL CONSTRUCT THE FIRST LAYER OF TENSAR Ir¡Ax GEOGRID OVER THE STRUCTURAL FILL CONTINUE WITH THE STRUCTURAL FILL AND TENSAR GËOGRID TO WITHIN 6-INCHES OF THE BOTTOI\4 OF SLAB ON GRADE ELEVATION. BACKFILL OVER THE LAST LAYER OF GEOGRID WITH 6.INCHES OT MINUS 3/4-INCH CLEAN CRUSH ROCK. ANY SUBSTITUTIONS MUST BE VERIFIED WITH THË ENGINEER. THE GEOGRID AND GEOTEXTILE PLACEMENT WILL BE ACCORDING TO THE MANUFACTURERS RECOMMENDATIONS, FOR STRUCTURAL FILL PLACEMENT OVEREXCAVATE: 4 FEET BELOW THE PROPOSED FOOIINGS ELEVATION 3 FEËT BELOW THE PROPOSED SLAB ON GRADE ELEVATION SLAB ON GRADE cfftL/çEoTEcENICÀI Engineering, Inc. P.0. Box 724, Eagle, CO 81631 Ie! (970) 39o-0307 www,LKPEngineering.com LKP STRUCTURAL FILL WTTH GEOGRID LOT 68, LOS AMIGOS RANCH, FILING 2 PHASE 2 683 MONARCH ROAD PN 239305107032 GARFIELD COUNTY, COLORADO PRDJECT NO l 22-3628 scALE: N.T.s. 5 FIGURE NO.: