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HomeMy WebLinkAboutGeotechnical Engineering Investigation 09.03.2024w cTL tTll$fi,r psoHffi GEOTECHNICAL ENGINEERING INVESTIGATION \ .N N N\. N LONG RESIDENCE 1O1O COUNTY ROAD 223 GARFIELD COUNTY, COLORADO Prepared for: Randy Long 279 County Road 216 Rifle, CO 81650 CTLIT Project No. GSOBB3.000-120 September 3,2024 GTllThqmpson, lnc. Denver, Fort Collins, Colorado Sprinos, Glenwood Sprinss, P!gb!q, Summit Countv - Colorado ftyemg, t ty"*ing ard pg3g ,, Montana ffi 0 100 1000 NOTE:SATELLITE IMAGE FROM MAXAR (C0PYRTGHT 2A24) SCAIE! t'- 1000' RANDYLONG 101l, COUNTY nOAD 223 cruT PHOJECT NO. GSO6883.OOO-120 Vicinity Map toou. tl,c _3 Fls. 1 LTGTND: TP_1 APPROXIMATE LOCATION OF I EXPLORATORY PIT ffi 0 30 60 NOTE: SCALET 1'- 60' RANDYLONO 10ro couNw RoAD atlt crLJT PROJECT NO. GSO6883.OOO-120 SATELLITH IMAGE FROM GOOGLE EARTH (DATED JUNI 6, 2023) ut ,4 7 .1) F.)N e.l toou >\ c :Jo(J 0)c(,J co ?.o4)ofL 1a .,. :. a, ?. :a: 4*t:'.t ': ? ?4 3 ;. '1 t ? z tt & Aerial Photograph TP-4 TP*3 TP-1 TP-2 Flg. 2 w Table of Contents scoPE..,... SUMMARY OF CONCLUSIONS SITE CONDITIONS PROPOSED CONSTRUCTION,......,., stTE GEO1OGY...............,......... ..... SUBSURFACE CONDITIONS,,......., SITE EARTHWORK..... Excavations Subexcavation and $tructural Fi||.........'....., Foundation Wall Backfi11.................' FOUNDATrON ................ SLAB-ON.GRADE CONSTRUCTION ............ FOUNDATION WALLS SURFACE DRAINAGE SUBSURFACE DRAINAGE............,.... CONCRETE CONSTRUCTION OBSERVATIONS GEOTECHNICAL RISK LtMtTATIONS .....",......... FIGURE 1-VICINIryMAP FIGURE 2 - AERIAL PHOTOGRAPH FIGURE 3 - SUMMARY LOGS OF EXPLORATORY PITS FIGURE 4 - SWELL-CONSOLIDATION TEST RESULTS FIGURE 5 - FOUNDATION WALL DRAIN CONCEPT TABLE I* RESULTS OF LABORATORY TESTING RANDY LONG 101O COUNTY ROAD 223 CTLIT PROJECT NO. GS06883.000-120 ..9 ..9 1A 11 11 12 .....12 ffi SCOPE This report presents the results of our geotechnical engineering investigation for the residence planned at 1010 County Road 223 (aka 1010 Peterson Road) in Garfield County, Colorado. We conducted this investigation to evaluate subsurface conditions at the site and provide geotechnical engineering recommendations for the proposed con- struction. The scope of our services was set forth in our Proposal No. G$ 24-0102. Aur report was prepared from data developed from our field exploration, laboratory testing, engineering analysis, and our experience with similar conditions. This report includes a description of the subsurface conditions observed in our exploralory pits and presents geotechnical engineering recommendations for design and construction of foundations, floor system, and details influenced by the subsoils. Recommendations contained in this report were developed based on our understanding of the proposed construction. A summary of our conclusions is below. SI."'MMARY OF COzuCLUSIONS Subsurface conditions encountered in our exploratory pits excavated at the site consisted of sandy to silty clay with layers of clayey to silty sand to the maximum excavated depth of '10 feet. Groundwater seepage was found in TP-1 ,TP-z, and TP-3 at depths of 4"5,3, and 6 feet, respectively. The natural sandy to silty clay soils found in our exploratory pit excava- tions were soft to stiff and moist io very moist. Based on our field and la- boratory data, and our geotechnical engineering experience, the natural clay soils have potential for low to moderate volume change when sub- jected to building loads. Floors in ihe garage area of the building are planned as slabs-on-grade. Building floor slabs can be supported by the undisturbed natural soils with additional risk of floor settlement and cracking. To reduce risk of potential slab settlement, we recommend subexcavation of the soils below the slab to a depth of at least 3 feet and replacement with densely-compacted structural fill. A foundation wall drain should be constructed around the perimeter of be- low-grade areas to mitigate water that infiltrates backfill soils adjacent to RANDY LONG ,I01O COUNTY ROAD 223 cTLlr PROJECT NO. GS06883.000-120 1 2 3 4 Page 1 ot 13 w the residence. Site grading should be designed and constructed to rapidly convey surface water away from the building. SITE CONDITIONS The residence is planned a|1010 County Road 223 an Tract 22 of the ACH Rifle Antlers Orchard Development in Garfield County, Colorado. A vicinity map with the loca- tion of the site is shown on Figure 1. An aerial photograph of the site is included as Fig- ure 2. No structures were present in the area planned for the residence at the time of our subsurface investigation. Ground surface at the site is generally flat with slopes down to the south at grades less than 5 percent. We understand flood irrigation practic- es have been utilized on the property which likely contributes to the soft soils and groundwater seepage encountered in our pits. PROPOSED CONSTRUCTION We reviewed plans for the building by Kristyn's Designs (dated February 20, 2024). The building is planned as a one-story steel structure with garage and living are- as. We anticipate the residence will be constructed on a footing foundation with crawl space below living area floors. $lab-on-grade floors are expected in the garage area. We anticipate maximum foundation excavation depths of about 4 feet are likely to con- struct the building. SITE GEOLOGY As parl of our investigation, we reviewed geologic mapping by the U.S. Geologic Survey (USGS) titled, "Geologic Map of the Silt Quadrangle, Gadield County, Colora- do", by Shroba and Scott (dated 2001). The site is mapped as undivided alluvium and colluvium of the Holocene and late Pleistocene. Subsurface conditions found in our ex- ploratory pits excavated at the site are consistent with the geologic mapping. No signifi- cant geologic hazards were identified that would preclude the planned construction. RANDY LONG 101O COUNTY ROAD 223 crLlT PROJECT NO. GS06883.000-120 Page 2 of 13 ---ltftF-ffi $t"., tssu RFACE colu Dlfl olvs Subsurface conditions at the site were investigated by observing the excavatian of four exploratory pits (TP-1 through TP-4) at the approximate locations shown on Fig- ure 2. Subsoils encountered in our exploratory pits consisted of sandy to silty clay with layers of clayey to silty sand to the maximum excavated depth of 10 feet. Groundwater seepage was encountered in our exploratory pits TP-1 ,TP-2, and TP-3 at 4.5, 3, and 6 feet below ground surface, respectively. Pits were backfilled immediately after explora- tory excavation operations were completed. Graphic logs of the soils observed in the exploratory pits are shown on Figure 4. A photograph of the soils excavated from our exploratory pit,TP-2, is shown below. Soils encountered in TP -2 Samples of the soils obtained from our exploratory pits were returned to our la- boratory for testing. Four samples selected for engineering index testing contained 41ta RANDY LONG 101O COUNTY ROAD 223 cTLIT PROJECT NO. GS06883.000-120 Page 3 of 13 w 64 percent silt and clay (passing the No. 200 sieve) and exhibited Liquid Limits of 2A b 24 percent and Plastlcity lndices of 1 to 9 percent. The natural sandy clay exhibited vol- ume change of 0.1 percent swell when wetted under a load of 1,000 psf. Swell- consolidation test results are shown on Figure 4. Laboratory testing is summarized on Table l. SITE EARTI.IWORK Excavations Maximum foundation excavation depths of less than about 5 feet are anticipated. Our subsurtace investigation indicates that excavations at the site can be accomplished using conventional, heavy-duty excavating equipment. Sides of excavations need to be sloped or retained to meet local, state, and fed- eral safety regulations. The subsoils at the site will likely classify as Type B soils based on OSHA standards governing excavations. From a "trench" safety standpoint, tempo- rary slopes deeper than 5 feet that are not retained should be no steeper than 1 to 1 (horizontal to vertical) in Type B soils, Contractors are responsible for determining the actual OSHA soiltype when excavations are made and for maintaining safe excava- tions. Contractors should identify the soils encountered in excavations and ensure that OSHA standards are met. Groundwater seepage was encountered in our exploratory pits at the time of our subsurface investigation. We do not anticipate excavations to construct the proposed building will penetrate a free groundwater table. Excavations should be sloped to a gravity discharge or be directed to a temporary sump where groundwater or water from precipitation can be removed by pumping. RANDY LONG 101O COUNTY ROAD 223 crllr pRoJEcr NO. GS06883.000-120 Page 4 af 13 ffi $ubexcavation and Structural Fill Based on our field and laboratory data, and our geotechnical engineering experi- ence in the area, the natural soils at the site have potentialfor low to moderate volume change when wetted under building loads. We judge the footings and garage floor slab can be supported on the natural soils if risk of differential movement and slab cracking are acceptable. Risk of differential movement and floor slab cracking can be significantly reduced if the soil below the building footprint is subexcavated and replaced as properly-compacted, structuralfill to a depth of at least 3 feet below the bottom footings and slabs. The subexcavation pro- cess should extend at least 1 foot beyond the edges of the building perimeter. The subexcavated soil can be reused as structural fill, provided it is free of rocks larger than 3 inches in diameter, organic matter, and debris. A positive alternative would be to use imported CDOT Class 6 aggregate base course as structuralfill. The structur- al fill soil should be moisture-conditioned to within 2 percent of optimum moisture con- tent, placed in loose lifts of 8 inches thick or less, and compacted to at least 98 percent of standard Proctor (ASTM D 698) maximum dry density. Moisture content and density of structural fill should be checked by a representative of our firm during placement. Ob- servation of the compaction procedure is necessary. Foundation Wall Backfill Proper placement and compaction of foundation wall backfill is important to re- duce infiltration of sudace water and settlement of backfill. This is especially important for backfill areas that will support concrete slabs, such as driveways and patios. The ex- cavated soils free of rocks larger than 4 inches in diameter, organics and debris can be reused as backfill adjacent to foundation wall exteriors. lmport fill should be a CDOT Class 6 aggregate base course or similar material. RANDY LONG 101O COUNTY ROAD 223 cTLlr PROJECT NO. GS06883.000-120 Page 5 of 13 :.w7: -&. ililt!'!lt 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 compacted. The backfill should be compacted to 95 percent of standard Proctor (ASTM D 698) max- imum dry density. Moisture content and density of the backfill should be checked during placement by a representative of our firm. FOUFIDATION We judge the residence foundation and the garage floor slab can be supported on the natural soils if differential movement and slab cracking are acceptable. Differen- tial movement and slab cracking can be significantly reduced if the soil below the build- ing footprint is subexcavated and replaced with structural fill to a depth of at least 3 feet below the bottom of the slab. The subexcavation process should extend at least 1 fool beyond the edges of the building perimeter. Struciural fill should be in accordance with the Subexcavation and Structural Fill section. Recommended design and construction criteria for footings and a monolithic slab with turned down edges are below. These criteria were developed based on our analy- sis of field and laboratory data, as well as our engineering experience. Footings on Natural Soils The building can be constructed on footing foundations supported by the undisturbed, natural sandy to silty clay. Footings supported by the undisturbed natural soils can be designed for a maximum net allowable soil bearing pressure ofJjg!*[.The weight of backfill soils above the footings can be neglected for bearing pressure cal- culation. A friction factor of 0.30 can be used to calculate resistance to sliding be- tween concrete footings and the natural soils. Continuous wall footings should have a minimum width of at least 16 inch- es. Foundations for isolated columns should have minimum dimensions of RANDY LONG 101O COUNTY ROAD 223 CTLIT PROJECT NO. GS06883.000-120 1 2 3. 4 Page 6 of 13 24 inches by 24 inches. Larger sizes may be required, depending upon foundation loads, Grade beams and foundation walls should be well-reinforced. We recom- mend reinforcement sufficient to span an unsupported distance of at least 12feel. 6, The soils under exterior footings should be protected from freezing, We recommend the bottom of footings be at finished exterior grades for frost protection. The partment should be consulted regarding required ments. protection require- Footinqs on Structural Fill 1. The building can be constructed on footing foundations supported by a 3 feet thickness of densely-compacted structural fill. The structural fill should be in accordance with recommendations in the Subexcavatien-andSlruc- tural Fill section. Footings supported by a 3 feet thickness of densely-compacted structural fill can be designed for a maximum net allowable soil bearing pressure of 3,000 psf. The weight of backfill soils above the footings can be neglected for bearing pressure calculation. A friction factor of 0.35 can be used to calculate resistance to sliding be- tween concrete footings and the natural soils. Continuous wall footings should have a minimum width of at least 16 inch- es. Foundations for isolated columns should have minimum dimensions of 24 inches by 24 inches. Larger sizes may be required, depending upon foundation loads. Grade beams and foundation walls should be well-reinforced. We recom- mend reinforcement sufficient to span an unsupported distance of at least 12 feel. 6. The soils under exterior footings should be protected from freezing. We 5 2 3 4 5 recommend the bottom of footings be finished exterior grades for frost protection. The partment should be consulted regarding required ments. least 36 incherbelow n coffiing oe- protection require- RANDY LONG 101O COUNTY ROAD 223 crllT PROJECT NO. GS068B3.oo0-120 Page 7 of 13 -'-trf.!*- 1ilil SLAB.ON-G RADE CONSTRUCTIOhJ The floors in the garage area af the building will be constructed as slabs-on- grade. The natural clay soil at the site has potential for volume change when wetted. Slabs-on-grade can be constructed on the undisturbed natural soils with risk of floor de- flection and slab cracking. To reduce the potential for floor deflection and slab cracking, we recommend subexcavation of the soils below the floor slab to a depth of 3 feet and replacement with densely-compacted structural fill. The structural fill should be in ac- cordance with recommendations in the Subexcavation and Structrrral Fill section Based on our analysis of field and laboratory data, as well as our engineering experience, we recommend the following precautions for slab-on-grade construction at this site. Slabs should be separated from footing and column pads with slip joints which allow free vertical movement of the slabs. The use of underslab plumbing should be minimized. Underslab 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 sup- poded appliances. Exterior patio slabs 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 with shrinkage and curling. The lnternational Building Code (lBC) may require a vapor retarder be placed between the base course or subgrade soils and concrete slab-on- grade floors. The merits of installation of a vapor retarder below floor slabs depend on the sensitivity of floor coverings and building to moisture. A properly installed vapor retarder (10 mil minimum) is more beneficial be- low concrete slab-on-grade floors where floor coverings will be sensitive to moisture. RANDY LONG 101O COUNTY ROAD 223crllr PRoJECT NO. GS06883.000-120 1 2 3 4 5 Page 8 ol 13 =#-:: ]t11- FOUNDATION WALLS Foundation walls which extend below-grade should be designed for lateralearth pressures where backfill is not present to about the same extent on both sides of the wall, such as in crawl spaces. Many factors affect the values 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 should be used in design. For walls that can deflect or rotate 0.5 to 1 percent of wall height (depending upon the backfill types), design for a lower "ae- tive" lateral earth pressure may be appropriate. Our experience indicates typical below- grade walls in residences 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-rest" conditions. For backfill soils conforming with recommendations in the Foundation Wall Back- fill section that are not saturated, we recommend design of below-grade walls at tltis site using an equivalent fluid density of at least 50 pcf. This value assumes deflection; some minor cracking of walls may occur. lf very little wall deflection is desired, a higher design value for the "at-rest" condition using an equivalent fluid pressure of 60 pcf is recom- mended. SURFACE DRAINAGE Surface drainage is critical to the performance of foundations, floor slabs, and concrete flatwork. Surface drainage should be designed to provide rapid runoff of sur- face water away from the building. Proper surface drainage and irrigation practices can help control the amount of surface water that penetrates to foundation levels and con- tributes to settlement or heave of soils and bedrock that support foundations and slabs- on-grade. Positive drainage away from the foundation and avoidance of irrigation near RANDY LONG 1010 COUNTY ROAD 223 crLlT PROJECT NO. GS06883.000-120 Page 9 of 13 w the foundation also help to avoid excessive wetting of backfill soils, which can lead to increased backfill settlement. We recommend the following precautions. The ground surface surrounding the exterior of the building should be sloped to rapidly convey surface water away from the building in all direc- tions. We recommend a constructed slope of at least 12 inches in the first 10 feet (10 percent) in areas around the building, where practical. 2.Backfill around the foundation walls should be moisture-treated and com- pacted pursuant to recommendations in the Foundation Wall Backfill sec- tion. lncreases in the moisture content of the backfill soils after placement often results in settlement. Re-establishing proper slopes (owner mainte- nance) away from the building rnay be necessary. We recommend that the building be provided with roof gutters and down- spouts. The downspouts should discharge well beyond the limits of all backfill. Splash blocks andlar extensions should be provided at all down- spouts so water discharges onto the ground beyond the backfill. We gen- erally recommend against burial of downspout discharge pipes. 1 3. Landscaping should be carefully designed and maintained to minimize ir- rigation. Plants placed close to foundation walls should be limited to those with low moisture requirements. lrrigated grass should not be located with- in 5 feet of the foundations. Sprinklers should not discharge within 5 feet of foundations. Plastic sheeting should not be placed beneath landscaped areas adjacent to foundation walls. Geotextile fabric will inhibit weed groMh and allow some evaporation to occur. SUtsSUR,FACE DRAINAGE Some seepage likely occurs in the near-surface soils during snowmelt in spring and early summer. The extent and rate of seepage will fluctuate throughout the year. Frozen ground during spring runoff can also create a perched groundwater condition. These water sources, combined with water from precipitation and sudace irrigation, can infiltrate foundation backfill soils. This can cause wet or moist conditions in below-grade areas, such as lower levels and crawl spaces, and result in water pressure against foundation wall exteriors. We recommend that the residence be protected from wetting and hydrostatic pressures by installation of a foundation wall drain system. RANDY LONG 101O COUNTY ROAD 223 cTLlr pRoJECT NO. GS06883.000-120 4 Page 10 of 13 ---vryrr:---Ifirr*' lfrlt-- The foundation wall drain will collect water from subsurface seepage, as well as surface water that infiltrates backfill soil adjacent to exteriors of foundation walls. The foundation wall drain should consist of 4-inch diameter, slotted, PVC pipe encased in free-draining gravel. A prefabricated drainage composite should be placed adjacent to foundation walls. Care should be taken during backfill operations to prevent damage to drainage composites. The drain should discharge via a positive gravity outlet or lead to a sump where water can be removed by pumping. Gravity outlets should not be suscep- tible to clogging or freezing. lnstallation of clean-outs along the drainpipes is recom- mended. A foundation wall drain concept is shown on Figure 5. CONCRETE Concrete in contact with soil can be subject to sulfate attack. Our experience in the area is that sulfate concentrations in the soils at this site are low. For low levels of sulfate concentration, ACI 332-08, "Code Requirements for Residential Concrete", indi- cates there are no special cement requirements for sulfate resistance in concrete in contact with the subsoils. ln our experience, superficial damage may occur to the exposed surfaces of highly-permeable concrete, even though sulfate levels are relatively low, To controlthis risk and to resist freeze-thaw deterioration, the water*to-cementitious materials 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 ol6% +l- 1.5%. We recommend damp-proofing of grade beams and foundation walls in con- tact with the subsoils. CONSTRUCTION OBSHRVATION$ We recommend that CTLIT be retained to provide construction observation and materials testing services for the project, This would allow us the opportunity to verify whether soil conditions are consistent with those found during this investigation. lf oth- ers perform these observations, they must accept responsibility to judge whether the RANDY LONG 101O COUNTY ROAD 223 cTLlr pRoJEcr No. Gs06883.000-120 Page11af13 ---TfrlT-'. ff l11ll- recommendations in this report remain appropriate. lt is also beneficialto projects, from economic and practical standpoints, when there is continuity between engineering con- sultation and the construction observation and materials testing phases. 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 geotechnical rec- ommendations do not comprise an exact science. We never have complete knowledge of subsurface conditions. Our analysis must be tempered with engineering judgment and experience. Therefore, the recommendations presented in any geotechnical eval- uation should not be considered risk-free. We cannot provide a guarantee that the inter- action between the soils and the proposed building will lead to performance as desired or intended. Our recommendations represent our judgment of those measures that are necessary to increase the chances that the buildings will perform satisfactorily. lt is criti- cal that all recommendations in this report are followed. r-tMtTAT|O['S This report was prepared for the exclusive use of the client. The information, conclusions, and recommendations provided herein are based upon consideration of many factors including, but not limited to, the type of structures proposed, the geologlc setting, and the subsurface conditions encountered. The conclusions and recommenda' tions contained in the report are not valid for use by others. Standards of practice con- tinuously change in geotechnical engineering. The recommendations provided in this report are appropriate for about three years. lf the proposed building is not constructed within three years, we should be contacted to determine if we should update this report. Our explo ratory pits provide a reason able characterization of subsurface condi- tions at the site. Variations in subsurface conditions not indicated by the pits will occur We should be provided with architectural plans, as they are further developed, so we RANDY LONG 101O COUNTY ROAD 223 CTLIT PROJECT NO. GS06883.000-120 Page 12 of 13 w can provide geotechnical/geo-structural engineering input. This investigation was conducted in a manner consistent with that level of care and skill ordinarily exercised by geotechnical engineers currently practicing under simi- lar conditions in the locality of this project. No warranty, express or implied, is made. lf we can be of further service in discussing the contents of this report, please call. CTLITHOMPSON, tNC Craig A. Burger, P. Principal Engineet RANDY LONG 't0't0 couNTY RoAD 223 CTLIT pRoJECT NO. 6506883.000-120 Ryan Barbone, P.E. Division Manager rba rbo ne(O ctlth om pso n. qom Page 13 oI 13 TP-1 TP-2 g g 10 15 LEGEND: CLAY, SILTY, SANDY, LENSES OF CLAYEY TO SILTY SAND. SLIGHTLY MOISTTO VERY MOIST, SOFT TO sTrFF, BROWN. (CL, ML, SM, CL-ML) INDICATES A BULK SAMPLE FROM EXCAVATED SOILS. INDICATES HAND-DRIVE SAMPLE. V DEPTH OF GROUNDWATERSEEPAGEATTHETIME OF EXCAVATION. TP-3 TP-4 0 v 10 15 NOTES: EXPLOMTORY PITS WERE EXCAVATED WITH A TMCKHOE ON JULY 19,2024, PITS WERE BACKFILLED IMMEDIATELY AFTER EXPLORATORY EXCAVATION OPERATIONS WFRE COMPLETED, 2. LOCATIONS OF EXPLOMTORY PITS SHOWN ON FIGURES 2 AND 3 ARE APPROXIMATE. 3. THESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS, AND CONCLUSIONS IN THIS REPORT. w Summary Logs of Fi[B,"ratbry FIG.3 0 5tr Flillutr TFo- lr"lo t-trlul IF tUo F F RANDY LONG 101O COUNTY ROAD223 CTLIT PROJECT NO. GS06883.000-120 ffi 7 6 5 4 2 0 ,2 -3 z.g-4 az o-_x-c UJ ;szo-6o u) IJJuo- -7 =oo -o APPLIED PRESSURE . KSF Somple of CLAY, SANDY (cL) IU DRY UNIT WEIGHT. MOISTURE CONTENT= 141 17.9 $well-Consolidation Test Results ru0 PQF YoFromTP-4 AT 4 FEET RANDY LONG 1010 couNw RoAD 223 CTLIT PROJECT NO. GS06883.000-120 \ \ €L EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING ) LU FIG 4 tr SACKN\ SLOPE OSHA covER EilflRE wlnH Or PREFABRICA1ED DRAIMOE coMPosnE (ununruH oooo on eQuva,srD ATTACH PI.ASIIC SHEENNG TO TOUNDAllOil lvAl.l- 8, MINIMUM OR BFYOND f cRAwL sPAcE PgR cRAVEt WnH NOH-WOm{ GEOIEMIE EABRIC (MIRAFI 14ON OR EAUVATEilI). VAPOR BARRIER RECOMIiIEIIDED MINIMUM 1:1 SLOPE FROM BOTTOM OF FOONNO (wlllcHEvEn rs GREATER) ENC-dsE ptPE rN 1/2'TO 1-1/2' SCREENED ROCK. DfiEND GRAVEL IATERAI.LY TO FOONNG Al,tD AT tEASt 1/2 HAaW OF FOOTINC. RtL EHTIRE TRENCH WIIH GRAVEL .S-INCH D T'EIER PERFORA1ED RICID DMIN PIPE T}IE PIPE SHOUI.O BE PIACED IH A TRET.ICH WTI}I A SLOPE OF AT LEASI |/8-INCH DROP PgR FOOT OF DR'IN. NOIB lHE BOTTOM OF THE DRNN SHOUI..D BE AT IEAST 2 NCHS BELOW FOTTOI/I OF FOOTNC AT THE HIGHST PONT AilD SLOPE DOWI'IIYARD TO A POSfITVE CRAVT'Y OI,TLET OR TO A $UMP TV}IERE WA1ER CAI.I BE REIIO\EO ST PUMPING. Randy Long 'to10 oc,uNwRoAD 223 oTL\T PROJECT NO. GSO6883.OOO-120 Foundation Wall Drain Goncept STFUSTUML TLOON i&' Flg.5 TABLE I SUMMARY OF LABORATORY TESTING CTLIT PROJECT NO. GS06883.000-120 ffi DESCRIPTION CLAY, SILT, SANDY (CL.ML) CLAY, SANDY {CL) SAND. SILTY {SM) CLAY, SANDY (CL) CLAY, SANDY (CL) PASSING NO.200 SIEVE (%) 50 54 41 64 PERCENT SAND (%\ PERCENT GRAVEL (o/o\ SOLUBLE SULFATES (%) "SWELL (%\ 0.1 ATTEREERG LIMITS PLASTCIry INDEX e/o\ 6 9 1 o LIQUID LIMIT (%) 22 24 2A 24 DRY DENSITY {PCF) 101 MOISTURE CONTENT (%) 17.7 14.2 20.7 17.9 21.3 DEPTH {FEET) 0-5 4-9 5-6 4 s-7 EXPLORATORY ptT TP-1 TP-2 TP-3 TP.4 TP.4 -SWELL MEASURED UhIDER 1,OOO PsF APPLIED PRESSURE" NEGATIVE VALUE INDICATES CONSCIL}DATION,Page 1 of 1