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HomeMy WebLinkAboutSubsoil StudyI G rt *:rir*#nürniiiå*'"5020 Coun$' Road 154 Glenwood Springs, CO 81601 phone: (970) 945-7988 fax: (970) 945-8454 email : kaglenwoodl¿lkumarusa.com wlvw kumarusa.comÅn Ëmplpyçc ÕwÍrçd 0ornprny RECEIVÉÜce Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Sunlnit Courrty. Colorado JAN 1 I 2022 GARFIELD COUNTY COMMUN¡TY DEVELOPMENT SUBSOIL STUDY F'OR FOUIIDATION DESIGN PROPOSED RESIDENCE 152 RUSTY SPUR TRAIL NORTH OF CINDY'S WAY GARFIELD COUNTY, COLORADO PROJECT NO.21-7-306 MAY 4,2021 PREPARED FOR: CHELA MURILLO P.O. BOX 885 SILT, COLORADO 81652 cm u rillo2J53@email.com TABLE OF CONTENTS PURPOSE AND SCOPE OF STUDY PROPOSED CONSTRUCTION ..... SITE CONDITIONS FIELD EXPLORATION SUBSURFACE CONDITIONS ... FOLINDATION BEARING CONDITIONS DESIGN RECOMMENDATIONS FOUNDATIONS FOUNDATION AND RETAINTNG WALLS FLOOR SLABS UNDERDRAIN SYSTEM SURFACE DRAINAGE....... SEPTIC FIELD....... LIMITATIONS.......... FIGURE I . LOCATION OF EXPLORATORY BORINGS AND PITS FIGURE 2 - LOGS OF EXPLORATORY BORINGS AND PITS FIGURE 3 - LEGEND AND NOTES FIGURES 4TO 6 - SWELL-CONSOLIDATION TEST RESULTS FIGURES 7 AND 8 - USDA GRADATION TEST RESULTS TABLE I- SUMMARY OF LABORATORY TEST RESULTS TABLE 2- SUMMARY OF LABORATORY TEST RESULTS (USDA) a .l J aJ J 4 5 6 7 8 8 Kumar & Associates, lnc. o Project No. 21-7-306 PURPOSE AND SCOPE OF STUDY This report presents the results ofa subsoil study for a proposed residence to be located at 152 Rusty Spur Trail, Garfield County, Colorado. The project site is shown on Figure I . The purpose of the study was to develop recommendations for foundation and septic system design. The study was conducted in general accordance with our agreement for geotechnical engineering services to Chela Murillo, dated March29,2021. A field exploration program consisting of exploratory borings and pits was conducted to obtain information on the subsurface conditions. Samples of the subsoils and bedrock obtained during the field exploration were tested in the laboratory to determine their classification, compressibility or swell and other engineering characteristics. The results of the field exploration and laboratory testing were analyzed to develop recommendations for foundation types, depths and allowable pressures for the proposed building foundation. This report summarizes the data obtained during this study and presents our conclusions, recommendations and other geotechnical engineering considerations based on the proposed construction and the subsurface conditions encountered. PROPOSED CONSTRUCTION The building is proposed in the area roughly between exploratory boring locations shown on Figure l. The proposed residence will be a2,100 square foot, one story wood frame structure over a walkout basement. We assume excavation for the building will have a maximum cut depth of one level, about 8 feet below the existing ground surface. For the purpose of our analysis, foundation loadings for the structure were assumed to be relatively light and typical of the proposed type of construction. If building loadings, location or grading plans are significantly different from those described above, we should be notified to re-evaluate the recommendations contained in this report. SITE CONDITIONS The site was vacant at the time of our site visit. An access road had been graded into the site. The proposed building area slopes down to the south at l0 to l5 percent. Vegetation consists of grass Kumar & Associates, lnc. @ Project No. 21.7-306 1 and weed, sagebrush and alarge cottonwood tree to east of building area. Sandstone/siltstone bedrock outcrops to the southwest of building area. FIELD EXPLORATION The field exploration for the project was conducted on April l, 2021 . Two exploratory borings were drilled at the locations shown on Figure I to evaluate the subsurface conditions. The borings were advanced with 4 inch diameter continuous flight auger powered by a truck- mounted CME-458 drill rig. The borings were logged by a representative of Kumar & Associates, Inc. Samples of the subsoils were taken with a 2 inch I.D. spoon sampler. The sampler was driven into the subsoils at various depths with blows from a 140 pound hammer falling 30 inches. This test is similar to the standard penetration test described by ASTM Method D-1586. The penetration resistance values aÍe an indication of the relative density or consistency of the subsoils and hardness of the bedrock. Depths at which the samples were taken and the penetration resistance values are shown on the Logs of Exploratory Borings and Pits, Figure 2. The samples were returned to our laboratory for review by the project engineer and testing. Two pits were excavated in the proposed septic area to the south of the proposed house as shown on Figure I to evaluate subsurface conditions for septic design. The pits were dug with a mini- excavator backhoe. The pits were logged by a representative of Kumar & Associates, Inc. Samples of the subsoils were taken with disturbed sampling methods. Depths at which the samples were taken are shown on the Logs of Exploratory Borings and Pits, Figure 2. The samples were returned to our laboratory for review by the project engineer and testing. SUBSURFACE COI\DITIONS Graphic logs of the subsurface profiles encountered at the site are shown on Figure 2. Below about I foot of organic topsoil or 2 feet of clay fill in Boring 1, the subsurface materials in the house area consist of weathered claystone to hard claystone/siltstone or sandstone bedrock of the Wasatch Formation. The subsoils encountered in the exploratory pits in the septic area consist of 4 to 7 feet of silty sand and clay. Weathered claystone/siltstone was encountered in Profile Pit 1 at a depth of 5 feet with refusal to backhoe digging at7 feet. Practical auger drilling refusal was also encountered in the sandstone at Boring 2 at 3y2 feet. Kumar & Associates, lnc. @ Project No. 21-7-306 -3- Laboratory testing performed on samples obtained during the field exploration included natural moisture content, density and grain size analyses. Swell-consolidation testing was performed on relatively undisturbed drive samples ofthe weathered claystone and claystone/siltstone. The swell-consolidation test results, presented on Figures 4to 6, indicate low compressibility under relatively light surcharge loading and a low to high expansion potential when wetted under a constant light surcharge. Results of USDA gradation analyses performed on the subsoils encountered in the septic areaare presented on Figures 7 and8. The laboratory testing is summarized in Table 1. No free water was encountered in the borings or pits at time of our field work. The subsoils were slightly moist. FOUI{DATION BEARING CONDITIONS The bedrock materials encountered at the site possess low to high expansion potential when wetted. The expansion potential can probably be mitigated by a combination of load concentration or subexcavation and replacement with structural fill to reduce swelling in the event of wetting below the foundation bearing level. Surface runoff, landscape irrigation, and utility leakage are possible sources of water which could cause wetting. DESIGN RECOMMENDATIONS FOUNDATIONS Considering the subsurface conditions encountered in the exploratory borings and the nature of the proposed construction, we recommend the residence be founded with spread footings and at least 3 feet of structural fill placed on undisturbed natural soils/bedrock. The design and construction criteria presented below should be observed for a spread footing foundation system. l) Footings placed on at least 3 feet of structural fill overlying the weathered to hard bedrock can be designed for an allowable bearing pressure of 4,000 psf. The footings should also be designed for a minimum dead load pressure of 1,000 psf. In order to satisflz the minimum dead load pressure under lightly loaded areas, it may be necessary to concentrate loads by using a grade beam and pad system. Kumar & Associates, lnc. o Project No. 21-7-306 -4- 3) Wall-on-grade construction is not recommended at this site to achieve the minimum dead load. The structural fill should consist of imported 34-inch road base compacted to at least 98% of the maximum standard Proctor density at a moisture content near optimum. Based on experience, \rye expect initial settlement of footings designed and constructed as discussed in this section will be up to about I inch. There could be additional movement of around 1 inch if the bearing materials were to become wet. The footings should have a minimum width of l6 inches for continuous footings and 24 inches for isolated pads. Continuous foundation walls should be reinforced top and bottom to span local anomalies and limit the risk of differential movement. One method of analysis is to design the foundation wallto span an unsupported length of at least 14 feet. Foundation walls acting as retaining structures should also be designed to resist a lateral earth pressure as discussed in the "Foundation and Retaining Walls" section of this report. Exterior footings and footings beneath unheated areas should be provided with adequate soil cover above their bearing elevation for frost protection. Placement of foundations at least 36 inches below the exterior grade is typically used in this area. Prior to the footing construction, any existing fill, topsoil and loose or disturbed soils should be removed to at least lt/z feet beyond footing edges and the excavation level extended down at least 3 feet below bearing or onto cemented sandstone for the structural fill placement. A representative ofthe geotechnical engineer should observe all footing excavations prior to concrete placement to evaluate bearing conditions and provide density testing of the structural fill placed below footing grade. 4) 5) FOUNDATION AND RETAINING WALLS Foundation walls and retaining structures which are laterally supported and can be expected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 55 pcf for backfill consisting 2) 6) 7) Kumar & Associates, lnc. @ Project No. 21-7-306 -5- of the on-site fine-grained soils. Cantilevered retaining structures which are separate from the residence and can be expected to deflect sufficiently to mobilize the full active earth pressure condition should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 45 pcf for backfill consisting of the on-site fine-grained soils. All foundation and retaining structures should be designed for appropriate hydrostatic and surcharge pressures such as adjacent footings, traffic, construction materials and equipment. The pressures recommended above assume drained conditions behind the walls and a horizontal backfill surface. The buildup of water behind a wall or an upward sloping backfill surface will increase the lateral pressure imposed on a foundation wall or retaining structure. An underdrain should be provided to prevent hydrostatic pressure buildup behind walls. Backfill should be placed in uniform lifts and compacted to at least 90%o of the maximum standard Proctor density at a moisture content slightly above optimum. Backfill in pavement areas should be compacted to at least 95Vo of the maximum standard Proctor density. Care should be taken not to overcompact the backfill or use large equipment near the wall since this could cause excessive lateral pressure on the wall. Some settlement of deep foundation wall backfill should be expected even if the material is placed correctly and could result in distress to facilities constructed on the backfill. The lateralresistance of foundation or retaining wall footings will be a combination of the sliding resistance of the footing on the foundation materials and passive earth pressure against the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated based on a coefficient of friction of 0.40. Passive pressure of compacted backfill against the sides of the footings can be calculated using an equivalent fluid unit weight of 300 pcf. The coefficient of friction and passive pressure values recommended above assume ultimate soil strength. Suitable factors of safety should be included in the design to limit the strain which will occur at the ultimate strength, particularly in the case of passive resistance. Fill placed against the sides of the footings to resist lateral loads should be a nonexpansive material compacted to at least 95Yo of the maximum standard Proctor density at a moisture content near optimum. FLOOR SLABS The on-site soils possess an expansion potential and slab heave could occur ifthe subgrade materials were to become wet. Slab-on-grade construction may be used provided precautions are Kumar & Associates, lnc. @ Project No. 21-7-306 6- taken to limit potential movement and the risk of distress to the building is accepted by the owner. A positive way to reduce the risk of slab movement, which is commonly used in the area, is to construct structurally supported floors over crawlspace. To reduce the effects of some differentialmovement, nonstructural floor slabs should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Interior non-bearing partitions resting on floor slabs should be provided with a slip joint at the bottom of the wall so that, if the slab moves, the movement cannot be transmitted to the upper structure. This detail is also important for wallboards, stairways and door frames. Slip joints which will allow at least 1%-inches of vertical movement are recommended. Floor slab control joints should be used to reduce damage due to shrinkage cracking. Slab reinforcement and control joints should be established by the designer based on experience and the intended slab use. Placement of the basement slab on 3 feet of structural fill, similar to the fill placed under footings is also recommended. A minimum 4 inch layer of free-draining gravel should be placed immediately beneath basement level slabs-on-grade. This material should consist of minus 2-inch aggregate with less than 50Yo passing the No. 4 sieve and less than2Yo passing the No. 200 sieve. The free-draining gravel will aid in drainage below the slabs and should be connected to the perimeter underdrain system. Required fill beneath slabs can consist of a suitable imported granular material such as road base, excluding topsoil and oversized rocks. The fill should be spread in thin horizontal lifts, adjusted to at or above optimum moisture content, and compacted to at least95o/o ofthe maximum standard Proctor density. All vegetation, topsoil and loose or disturbed soil should be removed prior to fill placement. The above recommendations will not prevent slab heave if the expansive soils underlying slabs- on-grade become wet. However, the recommendations will reduce the effects if slab heave occurs. All plumbing lines should be pressure tested before backfilling to help reduce the potential for wetting. LINDERDRAIN SYSTEM Although groundwater was not encountered during our exploration, it has been our experience where bedrock is shallow that local perched groundwater can develop during times of heavy Kumar & Associates, lnc, @ Project No, 21-7-306 -7 - precipitation or seasonal runoff. Frozen ground during spring runoffcan also create a perched condition. Therefore, we recommend below-grade construction, such as crawlspace and basement areas, be protected from wetting by an underdrain system. The drain should also act to prevent buildup of hydrostatic pressures behind foundation walls. The underdrain system should consist of a drainpipe surrounded by free-draining granular material placed at the bottom of the wall backfill. The drain lines should be placed at each level of excavation and at least I foot below lowest adjacent finish grade, and sloped at a minimum lo/o grade to a suitable gravity outlet. Free-draining granular material used in the drain system should consist of minus 2-inch aggregate with less than 50o/o passing the No. 4 sieve and less than 2Yo passing the No. 200 sieve. The drain gravel should be at least lVz feet deep. Void form below the foundation can act as a conduit for water flow. An impervious liner such as 20 mil PVC should be placed below the drain gravel in a trough shape and attached to the foundation wall above the void form with mastic to keep drain water from flowing beneath the wall and to other areas of the building. SURFACE DRAINAGE The following drainage precautions should be observed during construction and maintained at all times after the residence has been completed: l) Excessive wetting or drying of the foundation excavations and underslab areas should be avoided during construction. Drying could increase the expansion potential of the claystone bedrock. 2) Exterior backfill should be adjusted to near optimum moisture and compacted to at least 95Yo of the maximum standard Proctor density in pavement areas and to at least90o/o of the maximum standard Proctor density in landscape areas. Free- draining wall backfill should be covered with filter fabric and capped with about 2 to 3 feet of the on-site clayey soils to reduce surface water infiltration. 3) The ground surface surrounding the exterior of the building should be sloped to drain away from the foundation in all directions. We recommend a minimum slope of l2 inches in the first 10 feet in unpaved areas and a minimum slope of 3 inches in the first l0 feet in paved areas. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. Kumar & Associates, lnc, o Project No. 21-7-306 -8- Landscaping which requires regular heavy irrigation should be located at least l0 feet from foundation walls. Consideration should be given to use of xeriscape to reduce the potential for wetting of soils below the building caused by irrigation. SEPTIC FIELD Two profile pits were excavated in the proposed septic area to evaluate the feasibility of an infiltration septic disposal system at the site. The two profile pits were dug at the locations shown on Fig. I and to the depths indicated on Figure 2. The soils exposed in the profile pits, below about 1 foot of topsoil, consist of Sandy Loam, down to the bottom of the pits at 7 to 8 feet. Based on the subsoils encountered in the pits, the septic area should be suitable for a conventional infiltration septic disposal system. A civil engineer should design the infiltration septic disposal system. LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this areaat this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings drilled and pits excavated at the locations indicated on Figure l, the proposed type of construction and our experience in the area. Our services do not include determining the presence, prevention or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. Our findings include interpolation and extrapolation of the subsurface conditions identified at the exploratory borings and pits and variations in the subsurface conditions may not become evident until excavation is performed. If conditions encountered during construction appear to be different from those described in this report, we should be notified at once so re-evaluation of the recommendations may be made. This 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 s) Kumar & Associates, lnc. @ Project No. 21.7.306 -9- monitor the implernentation of our recommendations, and to verifu that the rçcommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications of the recommendations presented herein. We recommend on-site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the geotechnical engineer. Respectfully Submitted, Knnl¿lr & ¡{sso*Í¿r**s, lxrc. Daniel E. Hardin, P Rev. by: SLP DEH/kac Xumar & Âsco tidl&g, lrtr;.'t Fraj*et No. ä1"T-3*6 F U''lÉ. APPROXIMATE SCALE-FEET 21 -7-306 Kumar & Associates LOCATION OF EXPLORATORY BORINGS AND PITS Fig. 1 F BORING 1 EL-=97.7' BORING 2 EL,=92.7' PtT-'l EL.=82.5' PII_2 EL.=78.4' 0 NM hiffi IVii?:ll '!:trtlìl¡.iu¡ø î 0 35/12 WC=5.5 DD=127 -200=81 50/1.5 I GRAVEL=3 I snNo=oa -l srLT= 1 6 CLAY= 1 3 l I GRAVEL=2 I s¡¡ro=zz I stLT= I J CLAY=1 3 5 5 Fl¡J tJ l! I-t--(L tdô 10 41 /6, 50/4 WC=3.9 DD= 1 28 40/6, 50/ 4.5 WC=7.1 DD= 1 50 so/ 4.5 WC=4.8 DD= 1 26 10 F--tJ Ldt! IrFfLt!o 15 66/12 WC=9.5 DD=126 15 20 50/ 1 .s 20 25 2550/3 50 30 21 -7-306 Kumar & Associates LOGS OF EXPLORATORY BORINGS AND PITS Fig. 2 LEGEND ñ TOPSOIL: SANDY SILTY CLAY, ROOT ZONE, LOOSE TO MEDIUM DENSE, SLIGHTLY MOIST, LIGHT BROWN. FILL: SANDY SILTY CLAY, SCATTERED GRAVEL, ROOTS AND ORGANICS, LOOSE To MEDIUM DENSE, SLIGHTLY MOIST, LIGHTLY BROWN. SAND AND CLAY (SC-CL); SILTY WITH SCATTERED ANGULAR GRAVEL, HARD, SLIGHTLY MOIST, MEDIUM BROWN. l-À rt Átl mmÈ:i#H VJ:!!Á I:UT!il WEAïHERED CLAYSTONE; BLOCKY, CALCAREOUS, HARD, SLIGHTLY MOIST, MIXED BROWNS AND PURPLE. CLAYSTONE/SILTSTONE BEDROCK; VERY HARD, SLIGHTLY MOIST TO DRY, GRAY. SANDSTONE/SILTSTONE BEDROCK; VERY HARD, SLIGHTLY MOIST, GRAY DRIVE SAMPLE, 2-INCH I.D. CALIFORNIA LINER SAMPLE. à I HAND DRIVE SAMPLE. -l orsruRaED BULK sAMPLE. I _t \c/1, DRIVE SAMPLE BLOW COUNT. INDICATES THAT 55 BLOWS OF A 14O-POUND HAMMER FALLING 50 INCHES WERE REQUIRED TO DRIVE THE SAMPLER 12 INCHES. I PRACTICAL AUGER DRILLING REFUSAL OR PRACTICAL DIGGING REFUSAL. NOTES 1 THE EXPLORATORY BORINGS WERE DRILLED ON APRIL 1,2021 WITH A 4-INCH DIAMETER CONTINUOUS_FLIGHT POWER AUGER. THE EXPLORATORY PITS WERE EXCAVATED WITH A MINI EXCAVATOR ON APRIL 1, 2021, 2. THE LOCATIONS OF THE EXPLORATORY BORINGS AND PITS WERE MEASURED APPROXIMATELY BY PACING FROM FEATURES SHOWN ON THE SITE PLAN PROVIDED. 3. THE ELEVATIONS OF THE EXPLORATORY BORINGS AND PITS WERE MEASURED BY INSTRUMENT LEVEL AND REFER TO THE BENCHMARK ON FIG. 1. 4. THE EXPLORATORY BORING AND PIT LOCATIONS AND ELEVATIONS SHOULD BE CONSIDERED ACCURATE ONLY TO THE DEGREE IMPLIED BY THE METHOD USED. 5. THE LINES BETWEEN MATERIALS SHOWN ON THE EXPLORATORY BORING AND PIT LOGS REPRESENT THE APPROXIMATE BOUNDARIES BETWEEN MATERIAL TYPES AND THE TRANSITIONS MAY BE GRADUÄI. 6, GROUNDWATER WAS NOT ENCOUNTERED IN THE BORINGS OR PITS AT THE TIME OF DRILLING OR DIGGING. 7, LABORATORY TEST RESULTS: WC = WATER CONTENT (%) (ASTM D2216); DD = DRY DENSITY (PCt) (ISTU D2216):_2OO = PERCENTAGE PASSING NO. 2OO SIEVE (ASTM 01140); GRAVEL = PERCENTAGE RETAINED ON NO. 4 SIEVE; SAND = PERCENTAGE PASSING N0.10 SIEVE AND RETAINED ON NO.325 SIEVE; SILT = PERCENTAGE PASSING NO. 325 SIEVE TO PARTICLE SIZE .002MM CLAY= PERCENT SMALLER THAN PARTICLE SIZE .O02MM 21 -7 -306 Kumar & Associates LEGEND AND NOTTS Fig.5 ti SAMPLE OF: Weolhered Cloyslone FROM:Boringl@5' WC = 3.9 %, DD = 128 pcf ft.E tol ru¡ulb opp¡y only to th.ilmpl¡ ù8bd, ftr t ¡tng Epod rhôll nôt bô râproducd. âxæpt i¡ lull, whôuì thå sdbñ opprovol ol(umor ond À!w¡otÉ. lnc. Sw.ll lomolidoüon hting Fdormd ìn rccordonc! wlth ffi D-45æ. EXPANSION UNDER CONSTANT PRESSURE UPON WETTING 2 JJ Ld =(n I z.o F- Õ =o(nzo C) o -1 -2 21 -7 -306 Kumar & Associates SWELL-CONSOLIDATION TEST RESULTS Fig. 4 t 2 I SAMPLE OF: Cloystone FROM:Boringl@7.5 WC = 7.1 %, DD = 130 pcf \ full. wlthod tha *tun opprovol ol Kumor ond tuedotr, lñc. Swlll Con¡ol¡doüoñ bt¡ng rdomd indc.oddnc. *lth ffi D-4544- EXPANSION UNDER CONSTANT PRESSURE UPON WETTING 6 5 4 J2IJ lJJ =(n t2 z.oÊ 3'loÎnz.ooo -1 -2 1.0 APPLIED PRESSURE - KSF t0 100 21 -7 -306 Kumar & Associates SWELL-CONSOLIDATION TEST RESULTS Fig. 5 I 5 2 1 òs JJ LJ =v) I zo F ô =C)lnz.oo 0 -1 2 3 4 I.O APPLIED PRESSURE - KSF 10 SAMPLE OF: Cloystone/Siltslone FROM: Boring 1 @ 10' WC = 4.8 7", DD = 126 pcf ) t ibd. ftr in Sw.ll EXPANSION UNDER CONSTANT PRESSURE UPON WETTING 21 -7 -306 Kumar & Associates SWELL-CONSOLIDATION TTST RESULTS Fig.6 ,.3, '!. "t. ".. I i.!..:)n.l .^ ,g-ðt , g HYDROMETER ANALYSIS SIEVE ANALYSIS ÏIMË READINGS U STANDARD ERIES CLEAR SQUARE OPENINGS 24 HB. 7 HR 1 MIN. #325I5 *140 #60 #35 #14 #10 #4 1 tlz' 3" 5'6" 8', 100 10 90 20 80 30 70 ot¡lz l-l¡J É, Fz. l¡JoÉ.tJ(L 40 60 (,z6 UI o_ Fz. UJoÉ. lJJ(L 50 50 60 40 70 30 80 20 90 '10 100 0.001 .002 ,005 .009 .019 .045 .106 .025 .500 1.00 2.00 4.75 DIAMETER OF PARTICLES IN N/ILLIMETERS 9,5 19,0 37.5 76.2 152 203 CLAY I I sANp I cRAu r II v.flNr I flNr I MroruM lcoARSrlv.coaRSEl SMALL I uEo¡ur¡ I uncr ì COBBLES GRAVËL 2 %SAND 72 %SILT 13 %CLAY 13 % USDA SOIL TYPE: Sandy Loam FROM: PP-1 @ 2'Io 4' t I I i I I /I I t 21 -7 -306 Kumar & Associates USDA GRADATION TEST RESULTS Fis. 7 .:t SIEVE ANALYSISHYDROIVETER ANALYSIS U.S, STANDARD SERIES #14A #60 #35 #18 #10 CLEAR SOUARE OPENINGS 24ËF. 7HR I MIN, #325 #4 3/4' 1 tl¿" 3" 5',6" 8', 100 't0 90 20 80 30 70 ô UJz ¡- t¡JÉ. l-z LdoÉl¡lÈ 40 60 ()zı(n o_ FzIJ()u L¡lfL 50 40 70 30 80 20 10 100 .04s .106 .025 .500 1.00 2.00 4.75 9.5 19,0 37,5 76.2 152 203 DIAMETER OF PAHTICLES IN MILLIMETERS CLAY COBBLES GRAVEL 3 %SAND 68 %SILT 16 %CLAY 13 % USDA SOIL TYPE: Sandy Loam FROM: PP-2 @ 1,5'to 3' //lt I I t I , T / ''-r-^' t ti I ... I / tt S¡LT COARSE SMALL MÊDIUM URGE 21 -7 -306 Kumar & Associates USDA GRADATION TEST RESULTS Fig. I r. I $rt i-iË*fi:ffir;ffi :i5ü -. "TABLE 1SUMMARY OF LABORATORY TEST RESULTSNo. 2l-7-306SOIL TYPEWeatheredClaystone/SiltstoneWeathered ClaystoneClaystoneClaystone/SiltstoneClaystone/Siltstone(o/olEXPANSION1.46.20.2losflEXPANSIONPRESSURE4,000000)51,200f%ìPLASTICINDEXÀTTERBERG LIMITS{%tLIQUID LIMITPERCENTPASSING NO.200 slEvEIISAND(%)GRADATION(%)GRAVELlocf)NATURALDRYDENSITYt27128130126126f%tNATURALMOISTURECONTENT5.33.97.14.89.5{f0DEPTH2y,57%0Il5SAMPLE LOCATIONBORINGI l{+rtåi€r,ffi:;llrFxriiå'*"TABLE 2SUMMARY 0F LABoRAToRY TEST RESULTS (USDA)No.21-7-306SAMPLE LOCATIONNATURALMOISTURECONTENT(%)NATURALDRYDËNSITY{pcf}GRADATIONUSDA SOIL TEXTUREPITDEPÏH(ft)GRAVEL{%)SAND("/6)SILT&CLAY{%)GRAVEL{%)SAND$tSILTt%lCLAY$tSOIL TYPEI2-427213l3Sandy Loam2lYz-3J68t613Sandy Loam