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Home My WebLink AboutSoils & Foundation Investigation Report 09.18.17ffi CTL I THOMPSON RECEIVED DEC 0 I 2017 GARFIELD COUNTY COMI¡lUNITY DEVELOPMEìiT SOILS AND FOUNDATION INVESTIGATION EPPERLY BARN VENADO ROAD GARFIELD COUNTY, COLORADO Prepared For: VANGAURD OPËRATIONS LLC 112Red Feather Trail Silt, Colorado 81652 Attention: Chase Pearl Project No. GS061 69.000-125 $eptember 18,?A17 ffi TABLE CIF CONTENTS scoPË,... SUMMARY OF CONCLUSIONS....... SITE COND¡TIONS PROPOSED CONSTRUCTlON............... SUBSURFACE CONDITIONS.., srTË EARTHWORK..,................ Structural F¡|i,....,........ Foundation Watl Backfill FOUNDATION Footings..,.... SLAB.ON-GRADE SURFACE DRAINAGË CONCRETE GEOTECHNICAL RISK 1rM|TATIONS.................. FIGURE 1 -VICINITY MAP FIGURE 2 - LOCATION OF ËXPLORATORY PIT FIGURE 3 _ SUMMARY LOG OF EXPLORATORY PIÏ FIGURE 4 _ SWELL/CONSOLIDATION TEST RESULTS TABLE I _ SUMMARY OF LABORATORY TESTING VANGUARD OPERATIONSLLC EPPERLY BARN PROJECT NO. GS061 36.000-1 25 C:lUsers\kkellogg\AppOala\Læa¡\Box\Box Edit\Oocuñêntsl$4LM09OgkKy-l lmyhWVjw::1GS06169.000 125 R'l.docx I 1 2 2 2 3 3 4 4 5 5 6 o 7 B ffi SCOPE This report presents the results of our soils and foundation investigation for the Epperly Barn on property accessed from Venado Road in Garfield County, Colorado. A vicinity map with the location of the site is shown on Figure 1. We conducted this investigation to evaluate subsurface conditions at the site and pro- vide geotechnical engineering recommendations for the planned building. Our re- port was prepared from data developed from our field exploration, laboratory test- ing, engineering analysis, and our experience with similar conditions. This report includes a description of the subsurface conditions obse¡ved in our exploratory pits and presents geotechnical engÍneering recommendations for design and construc- tion of foundatíons, floor slabs, and details influenced by the subsoils. A summary of our conclusions is presented below. SUMMARY OF CONCLUSIONS Subsoils encountered in our exploratory pits consisted of about 2 inches of gravel drive surface underlain by natural sandy clay to the total explored depth of I feet. Groundwater was not found in our ex- ploratory pits. The natural clay soil at this site possesses potential for from swell or consolidation when wetted. The building can be constructed on foot- ing foundatíons supported by the undisturbed, natural clay soil. Ad- ditional discussion and design and construction criteria for footing foundations are provided in the report. 4 3 A slab-on-grade floor can be constructed on the undlsturbed natural clay. Surface drainage should be designed to provide for rapid rernoval of surface water away from the building. 1 2 VANGUARD OPERÅTIONS LLC EPPERLY BARN PROJECT NO. GS06196.000-125 1 C:lUsErs\kkellogglAppOata\Læal\Box\Box Ed¡tlÞocumenls\S4A-M09D3kKy-l1ilyhWVjwlGS06169.000 12ã Rl.docx ffi SITE COND¡TIONS The propeñy is approximately 3 miles south of Silt. Access is via C.R. 311 to Venado Road. The existing barn is located on an approximately 0.8-acre gravel surfaced pad. Ground sudace at the building pad generally slopes down to the north at grades at about 5 percent. PROPOSED CONSTRUCTION The existing barn will be deconstructed. The new barn will be a 36 feet by 60 feet pre-engineered steel building. We expect maximum excavation depths of about 4 feet. Foundation loads along perimeter walls will likely be between 1,000 and 3,000 pounds per linear feet. Maximum interior colurnn loads are anticipated at 50 kips. SUBSURFACE COND¡TIONS Subsurface conditions at the site were investígated by observing the exca- vation of two exploratory pits at the approximate location shown on Figure 2. Sub- surface conditions obse¡ved in the pits were logged by our field representative who obtained samples of the soils. Subsoils found ín our exploratory pits con- sisted of about 3 inches of gravel driving sudace underlain by natural sandy clay to the total explored depth of I feet. Groundwater was not found in our pits at the tirne of excavation. The pits were backfilled after completion of our fiefd investiga- tion. Graphic logs of the soils observed in the exploratory pits are shown on Fig- ure 3. VANGUARD OPERATIONS LLC EPFERLY BARN PROJECï NO. GS061 96.000.{25 c:ìUsersu(kellö99\AppDataìLocâl\8ôxlBor( Ed¡tlDocumEnlB\S4Á_M0903kKy_l lmyhwVJwslGso6l 6g-000 125 Rl.docx 2 ffi Sarnples of the soils obtained in the field were returned to our laboratory for classification testing and soluble sulfate testing. One sample of the clay was se- lected for one-dimensional, swell-consolidation testíng. The sample exhibited low swell potential. $well-consolidation test results are shown on Figure 4, Labora- tory test results are surnmarized on Table l. SITE EARTHWORK We anticipate maximum excavation depths of about 4 feet to construct foot- ings. Our subsurface information indicates excavation will be in natural sandy clay soil. Excavations at the site can be accomplished with typical heavy-duty excava- tion equipment. Sides of excavations deeper than 4 feet need to be sloped to meet local, State, and federal safety regulations. The on-site soils will likely clas- sify as Type B soils based on OSHA críteria. Excavation in Type B soils should be sloped no steeper than 1 to t horizontal to vertical. Free groundwater was not encountered [n our exploratory pits during exca- vation operations, We do not anticipate ground water will be encountered in exca- vations for the proposed construction. We suggest excavations be sloped to a gravity discharge or to a temporary sump where water frorn precipitation and run- off can be removed by pumping. Structu,ral Fill A positive alternative to reduce risk of building differential movement from soil consolidation or swell would be to construct a 2-feet thick mat of densely-com- pacted, structuralfill below footings and the floor. Subexcavation to a uniform depth below the entire building footprint would allow use of larger compaction equipment and would result in rnore similar bearing conditions for all building com- ponents. We recommend that structural fill consist of the subexcavated clay soil, VANGUARD OPERATIONS LLC EPPERLY BARN PROJECT NO. GS06196.00û-125 3 c:\use¡61tkêllogg\¡AppDâta\Locål\Ëox\8ox Êd¡t\Documents\s4A-M09D3kKy-l lmyhwviw==\GS0ô1 69.000 I 25 Rl.docx ffi provided it is free of rocks larger than 3 inches, vegetation, and deleterious materi- als. The structural fill footprint should extend beyond the outside edge of the foot- ing a minimum distance of three feet. Structural fill should be moisture-conditioned to within 2 percent of optimum moisture content and placed in loose lifts of l0 inches thick or less. Structural filt should be compacted to 98 percent of standard Proctor (ASTM D 693) maximum dry density. Moisture content and density of structural fill should be checked by a representative of our firm during pfacement, Observation of the compaction proce- dure is necessary. Testing without observation can lead to undesirable perfor- mance. Foundation Wall Backfill Proper placement and compaction of foundation backfill is important to re- duce infiltration of surface water and settlement of backfill. Backfill should be placed in loose lifts of approximately 10 inches thick or less, moisture-conditioned to within 2 percent of optimum moisture content, and cornpacted to at least 95 per- cent of maximum standard Proctor dry density (ASTM D 693). Moisture content and density of the backfill should be checked during placement by a representative of our firm. FOUNDATION The natural clay soil at this site possesses potentialfor consolidation or swell when wetted. The building can be constructed on footing foundaiions sup- ported by the undisturbed, natural clay soil. Risk of differential settlement from wetting of the natural soil, would be reduced by constructing footings on a 2-!eet thick mat of densely-compacted structural fill below the foundation. Recommenda- VANGUARD OPERATIONS LL6 EPPERLY BARN PROJECT NO, GS06196.000-125 C:11'Jsèrslr{kollogg\AppDqtalLæal\8ox\Box Ed¡tlflocumeñlsìS4A-M09O3kKy_11myhr¡rWjF=\GS06163.0OO i25 Rl docx 4 ffi lions for design and construction of footings on structural fill and footing on the un- disturbed, natural clay soilare below, We recornmend footings be supported on structuralfill. Footinqs Footings placed on ihe undisturbed, natural clay soil or on a soil mat of structuralfill can be sized using a maximum allowable bearing pressure of 2,000 psf. Soils loosened during the excavatlon and forming process should be recompacted or removed prior to placing concrete, 2.Continuous wall footings shoufd have a minimum width of at least 16 inches. Column footings should have a minímurn dimension of 24 inches. Larger sizes may be required, depending upon foundation loads. Grade beams and foundation walls should be well reinforced, top and bottom, to span undisclosed loose or soft soil pockets. We rec- ommend reinforcement sufficient to span an unsupported distance of at least 12 Íeef. The soils under exterior footings should be protected from freezing. We recommend the bottom of footings be constructed at a depth of at least 36 inches below finished exterior grades, The Garfield County building department should be consulted regarding required depth. SLAB.ON-GRADE A slab-on-grade floor will be constructed in the building. A slab-on-grade floor can be constructed on the undisturbed natural clay. Similar to footings sup- ported directing on the natural clay, differential movement should be expected if the soils are significanily wetted after construction. A positive approach to en- hance slab performance would be to extend the subexcavation process below the entire building footprint and support the floor slab on a 2-feet thickness of densely- compacted structural fill VANGUARD OPERATIONS LLC EPPÉRLY BARN PROJEcT NO. GSoô1 96,000-125 C:\Ueerslkk€tloggl ppData\LocaltBox\BoxEdit\Documenls\S4A-M0gD3kKy-1lmyhWViw=:\GS06169,000J25Rl.docx I 3 4 5 ffi Floor slabs should be separated from exterior walls and interior bearing rnembers with slip joints which allow free vertical rnovement of the slabs. Exterior concreie flatwork should be isolated from the building, These slabs should be well-reinforced to function as independent units. Frequent controljoints should be provided, in accordance with American Concrete lnstitute (ACl) recommendations, to reduce problems associated wÍth shrinkage and curling. SURFACE DRAINAGE Surface drainage is critical to the performance of foundations, floor slabs, and concrete flatwork. Recommendations in this report are based on effective drainage for the life of the structure and cannot be relied upon íf effective drainage ís not maintained. GONCRETE Concrete in contact with soil can be subject to sulfate attack. We measured water-soluble sulfate concentration of 0.576 in one sample from this siie. For this level of sulfate concentration, ACI 332-08 Code Requirements for Residentíal Con- crefe indicates concrete shall be made with ASTM C150 Type V cement, or an ASTM C595 or C1157 hydraulic cement meeting high sulfate-resistant hydraulic cement (HS) designation and shall have a specified minirnum compressive strength of 3,000 psi at 28 days. Alternative combination of cements and supple- mentary cementÍtious materials, such as Class F fly ash, shall be permitted with acceptable test records for sulfate durability. VANGUARD OPERATIONS LLC EPPERLY BARN PROJECT NO. GS061e6.000-t25 6 Gt\Us€ß\kkellogglAppDats\Locat\Box\Box Édlt\Docur.r€rts\S44-M09D3kKy-l I myhWVje=\GS06169.000 126 Rl.docx ffi ln our experience, superficial damage may occur to the exposed surfaces of highly permeable concrete, even though sulfate levels are relatively low. To con- trol this risk and to resist freeze-thaw deterioration, the water-to-cementitious ma- terial ratio should not exceed 0.50 for concrete in contact with soils that are likely to stay moist due to surface drainage or high water tables. Concrete exposed to freezing and thawing should have a total air content of 6% ! 1.íVo. We recom- mend allwalls and grade beams in contact with the subsoils be water-proofed. GEOTEGHNICAL RISK The concept of risk is an important aspect of any geotechnical evaluation. The primary reason for this ís that the analytical methods used to develop ge- otechnical recornmendations do not comprise an exact science. The analytical toots which geotechnical engineers use are generalfy empirical and must be tem- pered by engineering judgment and experience. Therefore, the solutions or rec- ommendations presented in any geotechnical evaluation should not be considered risk-free and, more importantly, are not a guarantee thatthe interaction between the soils and that the proposed structure will perform as desired or intended. What the engineering recommendations presented in the preceding sections do consti- tute is our estimate, based on the information generated during this and previous evaluations and our experience in working with these conditions, of those measures that are necessary to help the building perform satisfactorily. This report has been prepared for the exclusive use of the client for the pur- pose of providing geotechnical design and construction criteria for the proposed project, The information, conclusions, and recommendations presented herein are based upon consideration of many factors including, but not limited to, the type of structure proposed, the geologic setting, and the subsurface condiiions encoun- tered. The conclusions and recomrnendations contained in the report are not valid VANGUARD OPERATIONS LLC EPPERLY BARN PROJËCT NO. GS0gr96.000-125 C:\Userstkk€llogg\AppÞalalLoıal\Box\Box Edit\Þocuménts\S4A-M09D3kKy-l lmyhvwjw:=lGS05169.000 t25 Rl.docx 7 ffi for use by others. Standards of practice continuously change in the area of ge- otechnical engineering. The recommendations provided in this report are appro- priate for three years. lf the proposed project is not constructed within three years, we should be contacted lo determine if we should update this report. LIMITATIONS Our exploratory pits were located to provide a reasonably accurate picture of subsurface conditions. Variations in the subsurface conditions not indicated by the pit will occur. This investigation was conducted in a manner consistent with that level of care and skill ordinarily exercised by geotechnical engineers currently practicing under similar conditions in the locality of this project. No warranty, express or im- plied, is made. lf we can be of further service in discussing the contents of this re- port, please call. '',jr ':,! tr("r J S J cc: CTL eer Via email to cpearl(ôvnrenerov.com weststar@rof.net VANGUARD OPERATIONS LLC EPPERLY BARN PROJECT NO. GSo6t 96.000-125 CdUsers\kkóllogglAppDåtâ\LocallBox\Bûx Edlt\Documsnrs\S4dM09D3kKy_1 tmyhWVJw==\GS0ô189.000 125 Rl.docx I tr ' I q o SCALE:1'= 3,O00' Vanguard Operatlng, LLC Epp€rty Bam Prdect No. GS061 69.000-1 25 Vicinity Map Flg. 1 SCALE:1'= 6O NOTE¡ LOCATIONS OF EXPLORATORY PITS ARE APPROXIMATE. tr Locatlons of Exploratory Pits Flg. 2 È N g In di I Vanguard Operatlng, LLC Epp.dy Båm ProJect No. GS061 69.000-1 25 TP-1 10 15 VANGAURD OPËRATING, LLC EPPERLY BARN PROJECT NO. GS06169.000{25 TP.2 ffiLEGEND: 00 55 n GRAVEL DRIVING SURFACE CLAY, SANDY, MEDIUM STIFF, SLÍGHTLY MOUSTTO MOIST, BROWN, RED, GREEN HANÐ DRIVEN SAMPLE. IND]CATES BULK SAMPLE ¡- l¡Jtu TL ï¡- u_ l¡Jô t-trl t,u TL ITF-(L tuô F F&(,óU É.f,o LooJ(,z do@øN oq o@ @oØa Iilo J:<Fzaô 1 ı () ôi @6FzUs¡()oc¡ Eôu o X0ú J ooJ F ÕÂÀs()(toJJ t4 Yg, &.U =(.(J 10 15 NOTES: ,1. EXPLORATORY PITS WËRE EXCAVAÏED ON AUGUST 24, 2017 WITH A EACKHOE. 2, LOCATIONS OF EXPLORATORY P¡TS ARE APPROXIMATE. 3. NO FREE GROUNDWATER WAS FOUND IN EXPLORATORY PITS AT TI.IE T¡ME OF EXCAVATION. 4. EXPLORATORY P¡TS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS CONTAINED IN TþII$ RÊPORT. Summary Logs of Exploratory FIG.3 ffi 'l 6 5 4 J 2 0 -1 _a -3 U, I APPLIED PRESSURE . KSF Somple of CLAY, SANDY (CL) From TP.z AT 2.5 FFFT VANGUARD OPERATIONS, LLC EPPERLY BARN PROJECT NO. GSo61 6s.000-1 25 ClUsorsljkÞtlogg\AppOsta\Locàl\Eûr\Box lor Ofüê?\581073622ìTåmp\qqpckxd4.lux\6S0€169.000-125-$well.xls -4 -5 -6 zIØz o-X UJ szoøtñIlú o. ËoO -7 -8 r-u ¡U DRY UNITWEIGHT= MOISTURE ÇONTENT= 103 12,2 ru0 PCF % Swell Consolidation Test Results tl EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING rrrtrll ¡. I , \ \ FIG" 4 TABLE ISUMMARY OF LABORATORY TÊSTINGPROJECT NO. GS06l69-125ffiDESCRIPTIONSANDYctAY, SANDY (CL)PASSINGNO.200SIEVElol"\79sHÊAK I' I KbNG'IH(uNcoNFrNEDcoMPRESSTON)IPSF)SOLUBLESULFATES(%\0.570LAPPLIEDPRESSUREtpsFr1.000SWELL(o/o\0.6PLASTICITYINÞËX(o/o\15LIQUIDLIMIT(o/o\aÈDRYDENSITY{PCF)103MOISTURECONTENÏ(%\8.312.2DEPTH(FÊET}6-8?TP-1TP-2- SWELL MEASURÊD WITH lOOO PSF APPLIÊD PRESSURE, OR Ë,STIMATED IN-SITU OVERBURDEN PRESSURË.NEGATME VALUÊ INDICATFS COMPRESSION-Pâge f of 1