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Home My WebLink AboutGeotechnical Engineering Investigation 01.22.2021ffi CTL I THOMPSONw RECEIVi;r,.i ."'îfr ,i'J,i"f.rtP#ilriî GEOTECHNICAL ENGINEERING INVESTIGATION ELK SPRINGS, LOS AMIGOS, LOT 7, FILING 8, PHASE 1 GARFIELD COUNTY, GOLORADO Prepared For: DAVID BROWN C/O STRYKER BROWN ARCHITECTS, P.C. 225 N, Mill Street, Suite 100 Aspen, CO 8161 1 Project No. GS06534.000-1 20 January 22,2021 234 Cenler Drive I Glenwood Springs, Colorado 81601 Telephone: g7ü-945.28U9 Fax: 97ö-945-7411 ffi TABLF OF CONTENTS SUMMARY OF CONCLUSIONS SITE CONDITIONS.. PROPOSED CONSTRUCTION ...,.....,. s¡TË GEO1OGY.........,.,... SUBSURFACE CONDITIONS 1 1 2 3 3 4 6 6 B I o SITE EARTHWORK......... Excavation... Structural Flll .......... Foundation Wall Backfill....;.r. ¡........ SURFACE DRAINAGE FOUNDATION.,. SLABS.ON-GRAD E CONSTRUCTION.. FOUNDATION WALLS SUBSURFACE DRAINAGI . . coNcRETE...,.". STRUCTURAL ENGINEERING SERVICES ....,.....,..... GEOTECHNICAL RISK LIMITATIONS CONSTRUCTION OBSERVATIONS DAVID BROWN FIGUREl_VICINITYMAP FIGURE 2 _AERIAL PHOTOGRAPH FIGURE3-SITESURVEY FIGURE 4 _ SUMMARY LOGS OF EXPLORATORY PITS FIGURE 5 _ GRADATION TEST RESULTS FIGURE 6 * FOIJNDATION WALL DRAIN CONCEPT TABLE I - SUMMARY OF LABORATORY TESTING ELK SPRINGS, PROJECT NO. LOS I\MIGOS, LOT 7, FILING 8, PHASE { GS06534,000t?0 TF SCOPE This report presents the results of our geotechnical engineering investiga- tion for the residence proposed on Ëlk springs, Los Amigos, Lot 7, Filing B, phase 1 in Garfield County, Colorado. We conducted this investigation to evaluate sub- surface conditions at the síte and provide geotechnical engineering recommenda- tions for the proposed construcJion. The scope of our investigation was set forth in our Proposal No. GS 20-0347. Our report was prepared from data developed from our field exploraiion, laboratory testing, engineering analysis and our experience with similar conditions. This report includes a description of the gubsurface condi- tions observed in the exploratory pits and presents our geotechnical engineering recommendations for design and construction of foundations, floor systems, be- low-grade walls, and details influenced by the subsoíls. We should be provided with architectural plans, as they evolve, so that we can provide geotechnical/geo. structural engineering input. A summary of our conclusions is presented below. SUMMARY OF CONCLUSIONS Subsurface conditions observed in our exploratory pits excavated at the site consisted of about 6 inches of topsoil over basalt cobbles and boulders 'in a matrix of sandy clay and silt. Densely-nested boul- ders prevented excavation deeper than 7 feet in our pits, Free groundwater was not found in the exploratory pits. we anticipate excavations at this site will be more difficult than usuar due to the dense cobbles and boulders. Voids resulting from removal of large boulders should be filled wíth densely-compacted, granular structural fill, Additionally, the large amount of cobbles and boulders in the natural soil may result in a significant percentage of the exca- vated soils that are unsuitable for reuse as fill and backfill. 3. We judge a footing foundation is appropriate for the residence. The footings should be supported by the undisturbed, cobble and boulder soil or densely-compacted, granular, structural fill. Design and con- struction criteria for footings are presented in the report. 4. We expect slab-on-grade construction can be supported by the un- disturbed, cobble and boulder soil or densely-compacted, granular DAVID BROWN eLiSpCrì.iéð,rosAM¡Gos,LorT,FrLrNGs,pHAsE 1 I PROJECT NO. GSo6534.000,{20 1 2. ffi 5. structural fill provided the fill is placed as reoommended in the report. Additionaldiscussion is in the report. The residence should be provided with a perimeter foundation clrain around below-grade areas. surface drainage should be designed and constructed to rapidly convey surface water away from tñe resi- dence. SITE CONDITIONS Elk springs, Los Amigos, Lot 7, Filing B, phase 1 is an approximately 2.6- acre parcelsoutheast of the intersection of Elk Springs Drlve and Kingbird Drive in Garfield County, Colorado. A vicinity map with the location of the site is included as Figure 1. The site is bounded by Elk Springs Drive at the north and northeast. A natural drainage swale trends down to the south along the west property bound- ary. An aerial photograph is shown on Figure 2. Ground surface in the building en- velope slopes down to the southwest at grades less than 10 percent. steeper slopes are along the swale. Vegetation consists of grasses and sparse sage, pin- yon, and juniper. Several inches of snow were on the ground at the time of our subsurface investigation. A photograph from our subsurface investigation is below. Looking south at TP-1 location DAVID BROWN ELK SPR|NGS, LOS AMIGOS, LOT 7, F|LÌNG 8, PHASE 1 PROJEGT NO. GS0G534.000-,t 20 2 ffi PROPOSED CONSTRUCTION we were provided with design development plans for the residence by stryker/Brown Architects, P,c, (dated January 7,2021). The plans indicate the residence will be a one-story, wood-framed building with a walkout basement lower levelthat daylights at the southwest. An attached garage will be near the main floor elevation at the north side of the residence. Slab-on-grade floors are ex- pected in the garage and lower levelof the residence. No crawl space areas are índicated. Several patios and decks will be adjacent to the building. Maximum foundation excavation depths wifl likely be less than 12 feet. Based on the plans, it does not appear that significant thickness of structural fíll is proposed below the building or exterior flatwork. Typical foundation loads for this type of construction are about 1,000 to 3,000 s per lineal foot of foundation wallwith maximum interior column loads of less than 50 kips. We should be pro- vided with architectural plans, as they evolve, so that we can provide geotech- nícal/geo-structural engineering input. SITE GEOLOGY As part of our geotechnical engineering investigation, we reviewed geologic mapping by the colorado Geological surve¡r títled, "Geologic Map of the catle Creek Quadrangle, Garfield County, Colorado", by Kirkham, Streufert, Hemborg, Thomas, and Stelling (dated 2014). The mapping indicates the site is underlain by basalt that was deposited by volcanic flows during the Miocene Epoch. The upper rock is fractured and weathered into boulders and cobbles. These rocks are in a matrix of sheetwash deposits of gravelly sand, sandy silt, and clayey silt. Subsur- face conditions encountered in our exploratory pits are consistent with the geologic mapping. DAVID BROWN ELK SPRINGS, LOS AMtcOS, LOT 7, FtLtNG 8, PHASE I PROJECT NO. cS06534,000-,t 20 3 ffi We also revieweclthe CGS mapping, "Collapoible Soils and Evaporite Karst Hazards Map of the Roaring Fork River Corridor, Garfield, Eagle and pitkin Coun- ties, colorado", by Jonathan L. White (dated zooz). The map indicates the subject site is adjacent to areas of unconsolidated surficial deposits that includes outwash deposits. These deposits are geologically, recent and typically loosely-packed, po- rous and dry. ln many casesi the soils have a potential collapse when wetted un- der load. Our subsurface investigation indicates the soils at the subject site are claslsupported by the basalt cobbles and bedrook with outwash materialfilling the voids between the rocks. We judge the potential for soil collapse is low at this site. SUBSURFACE CONDITIONS Subsurface conditions at the site were investigated by oboerving excavation of two explorätory pits (TP-1 and TP-2). ]"he pits were excavated with a trackhoe at the approximate locations shswn on Figures 2 and 3. Exploratory excavation operations were directed by our engineer, who logged subsurface conditions en- countered and obtained samples of the excavated soils. Graphic logs of the soils encountered in our exploratory pits are shown on Figure 4. Subsurface conditions observed in our exploratory pits consisted of about 6 inches of topsoil over basalt cobbles and boulders in a matrix of sandy clay and silt. Densely*nested boulders prevented excavation deeper thanT feet in both of our pits. Free groundwater was not found in our exploratory pits at the time of ex- cavation. The pits were backfilled immediately after excavation operations were completed. Photographs of conditions found in our exploratory pits are below, ÖAVID EROWN ELK SPRTNGS¡ LOS AMtcos, LoT 7, FILING 8, PHASE ,l PROJECT NO. GS06534.000-r20 4 ffi Conditions exposed in TP-2 ,s Soils excavated from TP-1 DAVID BROWN ELK SPRINGS, LOS AMIGOS, LOT 7, FILING 8, PHASE I PROJECT NO. cS06534.000-l 20 5 ffi Samples of the soils obtained from our exploratory pits were returned to our laboratory for pertinent testing, One sample of the soils selected for gradation analysis contained 50 percent gravel, 30 percent sand, and 20 percent silt and clay (passing the No. 200 sieve). Gradatisn tests are not inclusive of rocks lar.ger than 5 inches. We judge the soils are composed prêdominantly o-f cobbles and boulders. Gradation test results are shown on Figure 5. Engineering index testing on one sample of the matrix soil indicated low plasticity. Based our laboratory test- ing and our experience at nearby sites, the matrix soil has low to moderate poten- tial for expansion when wetted. One sample of the soil tested had a water-soluble sulfate content of 0.02 percent. Laboratory test results are summarized on Table l. SITE EARTHWORK Maximum foundation excavation depths will likely be less than 12 feet. Based on the plans, it does not appear that significant thickness of structural fill is proposed below the building or exterior flatwork. Excavation We anticipate excaVations at this site for the building and undergréund utili- ties will be more difficult than usual due to the dense cobbles and boulders. Heavy-duty excavation equipment will be necêssary. Excavations may require or be most efficiently made with blasting to loosen the soils. Large boulders should be expected. Voids below the building resulting from removal of lar:ge boulders should be filled with densely-compacted, granular structural fill in aceordance with recommendations in the Stru I Fillseetion. From a "trench" safety standpoint, sides of excavations need to be sloped or braced to meet local, state and federal safety regulations. The soils ençoun- tered in the excavation to construct the residence will likely classify as a Type C soíl based on OSHA standards governing excavations. Temporary slopes deeper DAVID BROWN ËLK SPR|NGST LOS AMIGOS, LOr 7, FtLtNc 8, pHASE I PROJECT NO, GSo6534.000.120 6 : : i t' I : ! : i : : . : : ffi than 5 feet that are not retained should be no steeper than 1.5 to 1 (horizontal to vertical) in Type C soils. Contractors are responsible for determining the actual OSHA soiltype when excavations are made and for maintaining safe excavations. lf the sides of the foundation excavation cannot be laid back, an earth retention system, such as soil nails or micropiles will be required. Free groundwater was not found in our exploratory pits. We do not antici- pate excavations for foundations or utilities will penetrate groundwater. We recom- mend against excavation during snowmelt. Excavations should be sloped to a gravity discharge or tö a temporary sump where water from precipitation and snowmelt can be removed by pumping. The ground surrounding the excavations should be sloped to direct runoff away fr.om the excavations. 9tructural Fíll Close control will be required for structural fill to raise grades for the build- ing and patios and/or to fill voids resulting from removal of large boulders. Areas that receive fill should be stripped of vegetation, organic soils and debris. Struc- tural fill below the building and patios should consist of an aggregate base course or pit run materialwith a maximum rock size of 3 inches. The on-site,soils free of rocks larger than about 6 inches, organics, and debris can be used as fill in land- scape areas. Structural fill should be placed in loose lifts of I inches thick or less and moisture-conditioned to within 2 percent of optimum moisture content. Structural fill should be compacted to at least 98 percent of standard Proctor (ASTM D 69S) maximum dry density. Moisture content and density of structural fill should be checked by a representative of our firm during placement. Observation of the com- paction procedure is necessary. Testing without observation can lead to undesira- ble performance¡ OAVID BROWN ELK SPRINGS, LOS AMIGOS, LOT 7, FILING 8, PHASE 1 PROJECT NO. GS06534.000-120 7 ffi Foundation Vl/all Backfill Proper placement and compaotion of foundation backfill is important to re- duce infiltration of surface water and settlement of backfill. Backfill compaction is especially important in areas that will support exterior slabs-on.grade, such as driveways and patios. Backfill that will support these structures should consist of an aggregate basê course or pit run maierialwith a maximum rock size of 3 inches' The natural soils can be used as backfill in areas that will not support structures, provided they are free of rocks larger than 4-inches in diameter, organ- ics, and debris. Backfill should be placed in loose lifts of approximately 10 inches thick or less, moisture-conditioned to within 2 percent of optimum moisture contont and cornpacted. Thickness of lifts will likely need to be about 6 inches if the¡.e are small confined areas of backfill, which limit the size and weight of compaction equip- ment. Foundation backfill soils below patio and driveway slabs should be com- pacted to at least 98 percent of maximum standard proctor (ASTM D 69g) dry density. Backfillsoils in landscape areas should be compacted to at least g5 per- cent of maximum standard Proctor (ASTM D 69S) dry density. Moisture content and density of the backfill should be checked during placement by a representative of our firm. observation of the compaction procedure is necessary. FOUNDATION Based on our subsurface ínformation from the site, we judge a footing foun- dation is appropriate for the residence. The footings can be supported direc¡y on the undisturbed, cobble and boulder sóil or densely-compacted, granular, str.uc- tural fill. Voids resulting from removal of large boulders should be filled with densely-compacted, granular, structuralfill in accordance with recommendations in the Struclural f-ill section. We shor¡ld be informed if structural fill thicker than 4 feet is proposed below the building so we can provide additíonal geotechnicaugeo- DAVIDËROWN ELK SpRtNcS; LOS AMI6OS, Lor 7, FtLtNç 8, PHASE 1 PROJECT NO. GS06534.000-1 20 B ffi struetural engineering input. Recommended design and construction criteria for footings are below. The footing foundation should be supported by the undisturbed, cob- ble and boulder soil or densely-compacted, granular, structurar fiil. we generally recommend a maximum A-footthickness of structural fill beloW footings. 2. Footings on the undisturbed, cobble and boulder soil or dense ly- compacted, granular, structural fill should be designed for a maxi- mum allowable soil pressure of 3,000 continuous wallfootings shoufd have a minimum width of at least 16 inches- Foundations for isolated columns should have minimum di- mensions of 24 inches by 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 10 feet. The soils beneath exterior footings should be protected from freez- ing. we recommend the bottom of footings be constructed at a depth of at leas!.!6 yr!ügS-þelow finished exterior grades. The Garfield County building department should be consulted regarding required frost protection depth. SLABS-ON.GRADE CONSTRUCTION Slab-on-grade floors are expected in the garage and lower level of the resi- dence. Based on the plans, it does not appear that significant thickness of struc- tural fill is proposed below the building or exterior flahn¡ork, We judge slab-on- grade construction can be supported by the undisturbed, cobble and gravel soil with low risk of differentíal movement. lf structural fill is required below slabs, it should be in accordance with recommendations in the Structural Fillsecfion. Un- desirable amounts of consolidation settlement could occur if.slabs are supported on structural fill thickness of 6 feet or greater. We recommend the following pre- cautions for slab-on-grade construction at this síte. DAVID BROWN ELK SpRtNcS, LOS AM|GOS, LOT 7, FtLtNc I, PHASE I PROJECT NO. GS06534.000-r 20 1 3 4 5 I ffi slabs should be separated from exterior wails and interior bearing members with slip joints which allow free vertical movement of the slabs, The use of underslab plumbing should be rninimized. undersrab plumbing should be pressure tested for leaks before the slabs are constructed. Plumbing and utilities which pass through slabs should be isolated from the slabs with sleeves and provided with flexible couplings to slab supported applíances. Exterior concrete flatwork should be isolated from the residence. These slabs should be well-reinforced to function as independent units, Frequent controljoints should be provided, in accordance with Amer- ican concrete lnstitute (ACl) recommendations, to r.èdúce problems associated with shrinkage and curling. FOUNDATION WALLS Foundation walls which extend below-grade should be designed for lateral earth pressures where backfill is not present to about the same extent on both sides of the wall, st¡ch as in basernent areas. Many tactors affect the vaf ues of the design lateral earth pressure. These factors include, but are not limited to, the type, compaction, slope and drainage of the backfill, and the rigidity of the wall against rotation and deflection. For a very rigid wall where negligible or very little deflection will occur, an "at-rest" lateral earth pressure shciuld be used in design. For walls which can de- flect or rotate 0.5 to 1 percent of wall height (depending upon the backfill types), Iower "active" lateral earth pressures are appropriate. Our experience indicates typical below-grade walls in residences can deflect or rotate slightly under normal design loads, and that this deflection results in satisfactory wall performance. Thus, the earth pressures on the walls will likely be between the "active" and "at- restl' conditions. 1 2 3 4 DAVID BROWN ELK SPRINGS, PROJECT NO, LOS AMtGOs, LOr 7, FtLtNç I, PHASE 1 GS06534.000-120 10 ffi For backfill conforming to recommendatíons in the Foundation WallBackflll section that is nöt saturated, we recomrnend design of below-grade walls using an equivale.nt fluid density of at least 45 pcf for this site. This equivalent densÍty does not include allowances for sloping backfill, surcharges or hydrostatic pressures. The recommended equivalent density assumes deflection; some minor craoking of wafls may occur. lf very little wall deflection is desired, a higher equivalent fluid densíty approaching the at-rest condition using a value of 60 psf may be appropri- ate for design. SUBSURFACE DRAINAGE Water from surfaee precipitation, snowmelt, and irrigation freouently flows through relatívely permeable backfill placed adjacent to a residence and collects on the surface of less permeable soils occurring at the bottom of foundation exca- vations. This process can cause wet or moist conditions in below-grade areas, such as basement and crawl spaces, after construction. We recommend an exte¡'ior foundation wall drain be installed around the perimeter of the basement level of the residence. The exterior foundation drain should consist of 4-inch diameter, slotted, PVC pipe encased in fr,ee-draining gravel. A prefabricated drainage composite should be placed adjacent to founda- tion walls. Care should be taken during backfill operations to prevent damage to draina$e composites. The drain should discharge via a positive gravity ou¡et, or lead to a sump pit where water can be removed by pumping. Gravity ouflets should not be susceptible to clogging or freezing. lnstallation of clean-outs along the drainpipes is recommended. The foundation wall drain concept is shown on Figure 6. DAVID BROW\¡ ELK SPRINGS, LOS AMtcOS, LOT 7¡ FtLtNG I, PHASE I PROJECT NO. G506534.000-120 : : : l l : I Iii I t : a l : : : : l :11 ffi SURFACE DRAINAGE Surface draínage is critical to the performance of foundations, floor slabs, and concrete flatwork. Surface drainage should be designed to provide rapid run- off of surface water away from the residence. Proper surface drainage and irriga- tion practices can help control the amount of surface wâter that penetrates to foun. dation levels and contributes to settlement or heave of soils and bedrock that sup- port foundations and slabs-on-grade. Positive drainage away from the foundation and avoidance of irrigation near the foundation also help to avoid excessive wel ting of backfill soils, which can lead to increased backfilt settlement and possibly to higher lateral earth pressLtres, due to increased weight and reduced strength of the backfill. We reeommend the following precautions. The ground surface surrounding the exterior of the residence shourd be sloped to drain away from the building in all directions. We recom- mend a minimum constructed slope of at least 12 inches in the first 10 feet (10 percent) in landscaped areas around the residence, where practical. Backfill around the foundation walls should be moistened and com- pacted pursuant to recommendations in the Foundation wall Backfill section. The residence should be provided with roof gutters and downspouts. Roof downspouts should discharge well beyond the limits of ail back- fill. Splash blocks and/or extensions should be provided at all down- spouts so water discharges onto the ground beyond the backfifl- We generally recommend against burial of downspout discharge. Where it is necessary to bury downspout discharge, solid, rigid pipe should be used, and the pipe should slope to an open gravity ouflet. lrrigation should be limited to the minimum amount sufficient to main- tain vegetation; application of more water will increase lÍkerihood of slab and foundation movements. Plants placed close to foundation walls should be limited to those with low moisture requirements. lrri- gated grass should not be located within 5 feet of the foundation. sprinklers should not discharge within 5 feet of foundations. Plastic sheeting shouJd not be placed beneath landscaped areas adjacent to foundation walls or grade beams. Geotextile fabric will inhibit weed growth yet still allow natural evaporation to occur, 1 2. 3 DAVID SROWN ELK SPR|NGS, LôS AM|GOS, LOT 7, FtLtNG 8, PHASE I PROJECT NO. GSoô534.000-120 12 ffi GONCRETE Concrete in contact with soil can be subject to sulfate attack. We measured a water-soluble sultate concentration of 0,02 percent in one sample of the soil from the site (see Table l). For this level of sulfate concentration, ACI 332-08, Code Re- quirements for Residential Concrefe, indicates there are no special requirements for sulfate resistance. ln our experience, superficial damage may occur to the exposed surfaces of highly-permeable concrete, even though sultate levels are relatively low. To con- trol this risk and to resist freeze{haw deterior:ation, the water-to-cementitious ma- terials 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 should have a total air content of 6% +l- 1.5%. We recommend all foundation walls and grade beams in contacf with the subsoils be damp-proofed. CONSTRUCTION OBSERVATIONS We recommend that CTL I Thompson, lnc. be retained to provide construc- tion observation and materials testing services for the project. Thís would allow us the opportunity to verify whether soil conditions are consistent with those found during this investigation. lf others perform these observations, they must accept responsibility to judge whether the recommendations in this report remain appro- priate. lt is also benefícialto projects, from economic and practical standpoints, when there is continuity between engineering consultation and the construction observation and materials testing phases. STRUCTURAL ENGINEERING SERVICES CTL I Thompson, lnc.is a full-service geotechnical, structural, materials, and environmental engineering firm. Our services include preparation of structural framing and foundation plans. We can also design temporary and permanent earth DAVID BROWN ELK SPR|NGS, LOS AMIGOS, LOT 7, FtLtNc 8, PHASE 1 PROJECT NO. G506534.000.120 13 ffi retention systems. Based on our experience, crl I Thompson, lno, typically pro- vides value to projects from schedule and economic standpoints, due to our com- bined expertise and experienee with geotechnical, structural, and materials engi- neering. We can provide a proposal for structural engineering services, if re- quested. GEOTECHNICAL RISK The concept of risk is an important aspect of any geotechnical evaluation. The primary reason for this is that the analytical methods used to develop ge- otechnical recommendations do not comprise an exact science. The analytical tools which geotechnical engineers use are generally empirical and must be tem- pered by engineering judgment and experience. Therefore, the solutions or recom- n¡erldations presented in any geotechnícal evaluatíon should not be considered risk-free and, more importantly, are not a guarantee that the interaction between the soils and the proposed structuie will result in performance as desired or in- tended. The engineering recommendations presented in the preceding sections constitute our estimate of those measures 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 engineering design and construction critería for the proposed residence, The information, conclusions, and recommendations pre- sented herein are based upon consideration of many factors including, but not lim- ited to, the type of structufes proposed, the geologic setting, and the subsurface conditions encountered. The conclusions and recommendations contained in the report are not valid for use by others. Standards of practice continuously change in the area of geotechnical engineering. The recommendations provided in this report are appropriate for about three years. lf the proposed project is not constructed within three years, we should be coniacted to cletermine if we should üpdate this report. DAVID BROWN ELK SPRINGS, LOS AMIGOS, LOT 7, FILING 8, PHASE 1 PROJECT NO. GS06534.000-120 14 ffi L¡MITATIONS The exploratory pits provide a reasonable characterization of subsurface conditions at the site, Variations in the subsurface conditions not indicated by the pits will occur. We should be provided with architeetural plans, as they evÕlve, so we can provide geotechnical/geo-structural engineering input. This ínvestigation was conducted in a manner consístent with that level of care and skill ordinarily exercised by engineeríng geologists,and geotechnicalen- gineers currently practícing under similar: conditionS in the locality of this project. Ns other warranty, express or implied, is made. lf'we can be of further service in discussing the contents of this report, please call cTL I THOMPSON, tNC. fuPntL 'Ryán W. DeMars, E.l.T. Staff Engineer RWD:JDK:abr Reviewed es D. Division M "p2l 8298 DAVID EROWN E.LK SPRINGS¡ LOS AM|GOS, LOT 7! FtLtNG 8, PHASE I PROJECT NO. cS06534.000-t 20 l5 ffi 0 t000 2000Fæ:t ScAil: 1'- 2000' NOTE:SATELLITE IMAGE FROM GOOGLE EARTH (DATED JUNE 2017) DAVID BROVW{ ã.¡(3FANO8. LOBA'tilOo$, LoT?, FtuN(¡o, pt{AEE 1 PROJECT NO. C606634.OOO-í AO Vicinity Map Fls. 1 LEGEND: TP_1 APPROXIMATE LOCAÍ.ION OFr EXPLoRAToRY PIT APPROXIMATE PROPERTY BOUNÐARY NOTE: ,ffi 0 50 l(X,EtrtrFtr- sc¡t!: I'- foo' ÞAVID BFOWN ELKspRtN6B, l.06AtvtfcG, i-(rrz, FluNc B, pHAsE 1 PROJECT NO. GSO6534.OOO-1 20 SATELLITE IMAGE FAOM GOOGLE FARTH (oareo JUNE 2017) Aerial Photograph TP-1 TP*2 Fls. 2 ffi LEGEND: TP_1 APPROXIMATE LOCATION OFI EXPLoRAToRy Þir 0 50 100E¡EE-NOTE:BASE DRAWING PROVIDED BY STRYI(ER/BROWN ARCHTTECTS, PCSGALE: lt - lOOr or tl þuc 4a w ilH a /,t s tütfrtrsr' 1 \ \ \ l'tH .Þ DAVID BROWN EIJ( SPfllNGlË, LoS AtvttGCtS, lıt 7, F|UNô 8, plt¡Be r PROJECT NO. c606534.O00-1 20 LOr--6 1 \(¡ $ (¡¡ Itñ(¡¡ / r\¡,w sq.ft / / I \ 2.552 oc.*- I I l, I I UNUTY EASETIFN| L2r 7 Site Suruey Flg. 3 TP-1 TP-2 10 10 15 15 DAVIÐ BROWN ELK SPRINGS, LOS AMIGOS, LOT 7. FILING 8. PHASE 1 PROJECT NO. GS065M.000-1 20 TOPSOIL, SAND, SILTY, GRAVEL. ORGANICS, LOOSE, MOIST, BROWN. BASALT COBBLES AND BOULDERS, GRAVEL, SANDY CLAY AND SILT MATRIX, ÐENSE, MOIST, BROWN, GRAY, CALCAREOUS. INÐICATES BULK SAMPTE FROM EXCAVATED SOILS. PRACTICAL REFUSAL ON BOUDLËRS, ffi Summ ary Logs of Exploratóry FIG.4 0 5 LEGEND: F w T t-.-tIl TL IFIL llJo ¡- uJtrj LL TFfLulcl NOTES: 1. EXPLORATORYPITSWEREEXCAVATËD WITH A TRACKHOE ON DECEMBER 23, 2020, PITS WERE BACKFILLED IMMEDIATELY AF|ER EXPLORATORY ËXCAVAT¡ON OPERATIONS WERE COMPLETED. 2. GROUNDWATER WAS NOT FOUND IN OUR EXPLORATORY PITS AT THE TIME OF EXCAVATION. 3. LOCATIONS OF EXPLORATORY PITS ARE APPROXIMATE. 4. EXPLORATORYPITSARE SUBJECTToTHE EXPLANATIONS, LIMITATIONS AND CONCLUSÍONS CONTAINED IN THIS REPORT. ffi Somple of GRAVEL, cLAyEy (GC)From fn-Z nf ¿-b ¡CEf Somple of From DAVID BROWN ELK SpRtNcS , LOS AMtcos, LoT 7, FtLtNG 8, PHASE ,l PROJECT NO. GS06534.000-120 GRAVËL SILT & CLAY 20 PIAST|C|TY INOeX*-- 50 Vo SAND 30o/o LlQUllJ LIMIT o/o % o/o GRAVEL SILÍ & CLA* - PLASTICITY ¡NDEX % SAND To LIAUID L¡MIi % % % Gradation Test Results SANOScrAY (FLAS]'1C) TO StLT (NoN.pLAST|C) FINF MEDIUM coÀRsE FINÉ coARsÊ COBBLES YSIS '200 !100 '5ó '40 '30 .16 .10-.s .4 s/61 3t4" 1n" s" s"o. s' _ _.1_ -j-----]--1- _t_ -t__ __t_---_____+__----_l_---t- -----------l--__.-.-__-_..,t I--__- -___+___t_j*-t_t--.--_J- -----t-=--È__-t___ -----+---- -t-*--+---- - t_t_-t_--------r--------_-:-a---'-- -_,_,,- t_t_ _l_ -t-------+----- -l--l- -I r..ll--+_t___t_ ÞtA¡¡ETÊR oF pARTtcLÈ ¡N MtLLtMETÊRS MIN.l5 r00 90 80 0 't0 20 309706Ø Í60Fz u50ÉUr40 30 20 10 0 ,001 0,n02 .005 .019 .037 .074 _149 '1.19 2.0 2.38 4^76 9.52 19,1 36.1 25 ilR. 45 ¡nN. TIMERÉAbINGS 60 MlN, 1e MtN, 4 MtN. 1 MtN, .297 .5900.42 7 HR. 7ö.2 127 200 152 40 6ô 7A 80 100 SANDS GRAVELCLAY (PLAST|C) TO S|LT (NON-PLASTIC) FINE MÊDIUM COARSE FINÊ coARsÊ COBELES ANALYSIS 100 127 200 152 80 80 100 '16 ''t0'8 .4 10 2t 30 40 Fz 350üu9o 30 20 10 60 70 80 _001 0.002 .005 ,009 .019 .037 1 38.1 76.2 25 HR. PARTICLE IN U.€. STANDARO '200 'lOO '50'¡10 .30 CLÉAR SQUARÊ OPENINGS 318\ 3t4" 1/i' 3" 5'6" î74 .149 DIAMETER 45 MlN. 15 MtN, ô0 MtN. 19 MtN. 4 MtN, 1 MtN. .z97o.4z.sg0 1.19 t.0 ?.ao ¿,76 s.5a FIG.5 ffi c I e 2-3' BELOIY-CRAOE ITAII STOPE PER k--:".OSHA c(nÆR ORAì/EL DR.A¡l'lAGE @MPOSm (MTRADRA|N 6000 oR EQUTVAI.E]Ír) ATTACH PIåSIIC TO FOUNDATON SHEEÌING suP Jor'tÏ FOONNO OR PAD FROM FOOIINGs cnr¡reR) 4-INCH DIAMEÍER PERFORATEO RIOID DRA¡N THE PIFE SHOUI.Ð BE PIåCED IN A TRENCH ô_¡!o?E g¡ År trAsr t,/8-tNcH DROP pER FOOT OF DRAIN. ENCÁSE PIPE IN 1/2'TO 1-1/2'TYÁSHED GRAvEI. ÐflE}ID GRAvEL I.ATEñAILY To FoonNc Al'lD AT a.F-ì$r V2 HBcHt OF FOOnNc. Ftrr ENNRE TRENCH W!II{ CRAVEL NOTÉ IU-E_Þ9!'ÍqM-OI T}IE ORAIN SHOUI^D BE AT I.^EASÍ 2 INCHES BETOIY BOTTOM OF ¡9erlNc_ôT_THE HrcHEsr FoNr A¡¡D sLopE oownwnnú-ro A-posrnvg cRAiinyourLgr oR To A suMp tvHERE tvATER c¡r{ BE naliywo'w'pLuÞlño. OR Foundation Wall Drain Concept 8' MlNntut,l OR BFYOND1:l SLOPE BOTTOM OF (üftücHEVER PIPE. IYIH DÁVIDBROWN zu( spFtNg¡6.:Lo€¡ ÄÂflcos, r.('ïz, FtLNo a, pHAÊË I PROJECT NO. cSO6534.000-1 20 Flo- 6 TABLE ISUMüARY OF LABORATORY TESTINGPROJECT NO. GS06534.000-120ffiGCLANO.200SIEVE23PERCENTSAND30PERCËNTGRAVEL50SOLUBLESULFATES(o/o)LIMITINDEXNLNPDRYDENSITY(PCF)MOISTURECONTËNT(o/o\DEPTH(FEÊT)EXPLORATORYPITPage 1 of1