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HomeMy WebLinkAboutSoils Report 12.27.2019CTL I THOMPSON 1 14 C o; r o a a x 11 o GEOTECHNICAL ENGINEERING INVESTIGATION CARNAHAN RESIDENCE 3923 COUNTY ROAD 311 GARFIELD COUNTY, COLORADO Prepared For: DAVID RIPPY CONSTRUCTION, INC. 3950 Midland Avenue, Unit F2 Glenwood Springs, CO 81601 Attention: David Rippy Project No. GS06406.000-120 December 27, 2019 234 Center Drive Glenwood Springs, Colorado 81601 Telephone: 970-945-2809 Fax: 970-945-7411 TABLE OF CONTENTS SCOPE 1 SUMMARY OF CONCLUSIONS 1 SITE CONDITIONS 2 PROPOSED CONSTRUCTION 3 GEOLOGIC CONDITIONS 3 SUBSURFACE CONDITIONS 3 SITE EARTHWORK 5 Excavations 5 Subexcavation and Structural Fill 5 Foundation Wall Backfill 6 FOUNDATION 6 SLAB -ON -GRADE CONSTRUCTION 8 FOUNDATION WALLS 9 SUBSURFACE DRAINAGE 10 SURFACE DRAINAGE 10 CONCRETE 11 CONSTRUCTION OBSERVATIONS 12 STRUCTURAL ENGINEERING SERVICES 12 GEOTECHNICAL RISK 13 LIMITATIONS 14 FIGURE 1 — VICINITY MAP FIGURE 2 — AERIAL PHOTOGRAPH FIGURE 3 — LOCATIONS OF EXPLORATORY PITS FIGURE 4 — SUMMARY LOGS OF EXPLORATORY PITS FIGURE 5 — FOUNDATION WALL DRAIN CONCEPT TABLE I — SUMMARY OF LABORATORY TESTING DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 SCOPE This report presents the results of our geotechnical engineering investiga- tion for the Carnahan Residence proposed at 3923 County Road 311 in Garfield County, Colorado. The scope of our geotechnical engineering investigation was set forth in our Proposal No. GS 19-0267. Our 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 found in our exploratory borings and presents geotech- nical engineering recommendations for design and construction of foundations, floor systems, below -grade walls, subsurface drain systems and details influ- enced by the subsoils. A summary of our conclusions is below. SUMMARY OF CONCLUSIONS Subsurface conditions encountered in our exploratory pits were about 3 inches of topsoil over silty sandy clay to the total explored depth of 10 feet. Free groundwater was not found in our explora- tory pits at the time of excavation. Our experience in the area indicates the silty sandy clay possesses the potential for consolidation when wetted under building loads. The residence can be constructed on footing foundations, provided the soils below the entire area of the building footprint are subexca- vated to a depth of at least 3 feet. The excavated soils can be mois- ture -treated and replaced as densely -compacted, structural fill. The subexcavation process and design criteria for footings are in the re- port. Floors in the basement and garage areas will likely be slabs -on - grade. After the recommended subexcavation and recompaction process is accomplished below building footprint, we anticipate good performance of slabs -on -grade supported by an at least 3 -foot thickness of moisture -treated, densely -compacted structural fill. The residence should be provided with a perimeter foundation drain around below -grade areas. Surface drainage should be designed to rapidly convey surface water away from the building. DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 SITE CONDITIONS The Carnahan Residence is proposed at 3923 County Road 311 in Gar- field County, Colorado. A vicinity map with the location of the site is shown on Figure 1. The lot is a 100 -acre parcel accessed by County Road 311. An aerial photograph of the site is shown on Figure 2. County Road 311, Divide Creek, and an irrigation ditch run north -south through the property. A relatively flat area that appears to have been historically irrigated is west of the road and Divide Creek. The residence will be located west of the irrigated lands on a localized topographic bench. The irrigation ditch trends to the north at the base of steep slopes above and the west of the building site. Vegetation consists of grasses with sparse sage brush. A photograph of the site is below. DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 2 PROPOSED CONSTRUCTION Architectural plans were not developed at the time of our geotechnical en- gineering investigation. Based on conversations with the owner, we anticipate the residence will be a two-story, wood -framed building with the lower level con- structed as a walk -out basement. We do not know if a garage will be built. Slab - on -grade floors are likely in basement and garage areas. Maximum excavation depths will likely be on the order of 10 feet. Typical foundation loads for this type of construction are about 1,000 to 3,000 pounds per linear foot of foundation wall with maximum 50 -kip interior column loads. We should be provided with con- struction plans, when available, so that we can provide geotechnical/geostruc- tural engineering input. GEOLOGIC CONDITIONS We reviewed mapping by the U.S. Geological Survey (USGS) titled, "Re- vised Preliminary Geologic Map of the New Castle Quadrangle, Garfield County, Colorado", by Scott, and Shroba (dated 1997). The mapping indicates the over- burden soils in the proposed building area consist of flood plain and stream chan- nel deposits from relatively recent geologic time during the Holocene and Pleisto- cene Epochs. Subsoils encountered in our exploratory pits excavated at the site are consistent with the geologic mapping. SUBSURFACE CONDITIONS Subsurface conditions at the site were investigated by observing the exca- vation of two exploratory pits (TP -1 and TP -2) at the approximate locations shown on Figure 3. Subsoils encountered in our pits were logged by our engi- neer, who obtained samples of the soils during excavation operations. Graphic logs of the soils encountered in our exploratory pits are shown on Figure 4. DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 3 Subsoils encountered in our exploratory pits were about 3 inches of topsoil over sandy silty clay to the total explored depth of 10 feet. The soils were judged as medium stiff and moist. Free groundwater was not encountered in the pits at the time of excavation. The pits were backfilled immediately after drilling opera- tions were completed. A photograph of the excavated soils is below. Subsoil samples from our exploratory pits were returned to our laboratory where field classifications were checked and representative samples were se- lected for pertinent testing. Engineering index testing performed on two samples indicated liquid limits of 25 and 27 percent and plasticity indices of 8 and 11 per- cent. Laboratory testing results are summarized on Table I. DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 4 SITE EARTHWORK Excavations Excavations at the site to construct the proposed residence can be ac- complished using conventional, heavy-duty excavating equipment. From a "trench" safety standpoint, sides of excavations need to be sloped or braced to meet local, state and federal safety regulations. We expect the soils encoun- tered in excavations will classify as Type B soils based on OSHA standards gov- erning excavations. Temporary excavation slopes that are not retained should be no steeper than 1 to 1 (horizontal to vertical) in Type B soils. Contractors are re- sponsible for maintaining safe excavations. Free groundwater was not encountered in our exploratory pits. We do not anticipate excavations for the building foundation will penetrate the free ground- water table. We recommend excavations be sloped to a gravity discharge or to a temporary sump where water from precipitation can be removed by pumping. Subexcavation and Structural Fill Based on our field and laboratory data from the site, and our engineering experience, we judge the sandy silty clay soils at the proposed building location possess moderate potential for consolidation when wetted under building loads. The residence can be constructed on a footing foundation and with a slab -on - grade basement floor, provided the soils below the building are subexcavated to a depth of at least 3 feet below planned bottom of footing elevation and replaced with densely -compacted, structural fill. The subexcavation process should ex- tend at least 1 foot beyond the edge of the building perimeter. The subexcavated soils, free of organic matter, debris and rocks larger than 3 inches in diameter can be re -used as structural fill. The structural fill soils should be moisture -conditioned to within 2 percent of optimum moisture content DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 5 and placed in loose lifts of 8 inches thick or Tess. Structural fill should be com- pacted 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. Observation of the compaction pro- cedure is necessary. Foundation Wall Backfill Proper placement and compaction of foundation backfill is important to re- duce infiltration of surface water and settlement of backfill. The soils excavated from the site can be used as backfill, provided they are free of rocks larger than 3 -inches in diameter, organics, and debris. Backfill soils should be moisture -con- ditioned to within 2 percent of optimum moisture content placed in loose lifts of approximately 10 inches thick or less and compacted. Thickness of lifts will likely need to be about 6 inches if there are small confined areas of backfill, which limit the size and weight of compaction equipment. Backfill should be compacted to at least 95 percent of maximum standard Proctor (ASTM D 698) 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 Our experience in the area of the site indicates the silty sandy clay pos- sesses the potential for moderate consolidation when wetted under building loads. The residence can be constructed on footing foundations, provided the soils below the entire area of the building footprint are suhexcavated to a depth of at least 3 feet below planned bottom of footing elevation. The excavated soils DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 6 pacted structural fill soils can be moisture -treated and reused to build a mat of densely -compacted, struc- tural fill below the building. Subexcavation and structural fill should be in accord- ance with recommendations in the Subexcavation and Structural Fill section. We expect the subexcavation and structural fill process will result in good performance of footings, however, some risk of differential settlement will still ex- ist. It will be critical to adhere to recommendations in the SUBSURFACE DRAINAGE and SURFACE DRAINAGE sections. Recommended design and construction criteria for footing foundations are presented below. The residence can be constructed on footing foundations supported by an at least 3 -foot thickness of moisture -treated, densely -com- . Soils loosened during the forming pro- cess for the footings should be removed or re -compacted prior to placing concrete. Footings on the structural fill can be sized using a maximum allowa- ble bearing pressure of 2,000 psf. 3. Continuous wall footings should have a minimum width of at least 16 inches. Foundations for isolated columns should have minimum dimensions of 24 inches by 24 inches. Larger sizes may be re- quired, 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 feet. 5. The soils under exterior footings should be protected from freezing. We recommend the bottom of footings be constructed at a depth of DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 7 at least 36 inches below finished exterior grades. The Garfield County building department should be consulted regarding required frost protection depth. SLAB -ON -GRADE CONSTRUCTION We expect slab -on -grade floors in basement and garage areas. Soils be- low the entire area of the building footprint should be subexcavated to a depth of at yeast 3 feet below planned bottom of footing elevations. The excavated soils can be moisture -treated and reused to build a mat of densely -compacted, struc- tural fill below the building. A 1 -foot thickness of structural fill is recommended below exterior slabs and flatwork. Sub -excavation and structural fill should be in accordance with the recommendations outlined in the Subexcavation and Struc- tural Fill section. We expect the subexcavation and structural fill process will result in good performance of garage slabs, however, some risk of differential settlement will still exist. It will be critical to adhere to recommendations in the SUBSURFACE DRAINAGE and SURFACE DRAINAGE sections. We recommend the following precautions for slab -on -grade construction at this site. 1. Slabs should be separated from exterior walls and interior bearing members 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 supported appliances. DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 8 3. Exterior patio and porch slabs should be isolated from the building. These slabs should be well -reinforced to function as independent units. Movements of these slabs should not be transmitted to the building. 4. Frequent control joints should be provided, in accordance with American Concrete Institute (ACI) recommendations, to reduce 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, such as adjacent to basement and crawl space areas. Many factors affect the values of the design lateral earth pressure. These factors in- clude, 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 de- flect or rotate 0.5 to 1 percent of wall height (depending upon the backfill types), lower "active" lateral earth pressures are appropriate. Our experience indicates typical below -grade walls in residences deflect or rotate slightly under normal de- sign Toads, 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. If the on-site soils are used as backfill and the backfill is not saturated, we recommend design of below -grade walls at this site using an equivalent fluid den- sity of at least 50 pcf. This value assumes deflection; some minor cracking of walls may occur. If very little wall deflection is desired, a higher design value for the "at -rest" condition is appropriate using an equivalent fluid pressure of 60 pcf. DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 9 SUBSURFACE DRAINAGE Water from surface precipitation, snowmelt, and irrigation frequently flows through relatively permeable backfill placed adjacent to a residence and collects on the surface of Tess permeable soils occurring at the bottom of foundation ex- cavations. This process can cause wet or moist conditions in below -grade areas, such as basements and crawl spaces, after construction. It can also result in subsurface wetting below the building, which can cause volume changes in the soils and differential building movement and associated damage. We recommend that an exterior foundation drain be installed around the perimeters of the basement and crawl spaces (if constructed) below the resi- dence. The exterior foundation 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 lead to a positive gravity outlet, or to a sump pit where water can be removed by pumping. Gravity outlets should not be susceptible to clogging or freezing. In- stallation of clean -outs along the drain pipes is recommended. The foundation drain concept is shown on Figure 5. 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 surface water away from the residence. Proper surface drainage and ir- rigation practices can help control the amount of surface water that penetrates to foundation levels and contributes to settlement or heave of soils and bedrock that support the foundation and slabs -on -grade. Positive drainage away from the foundation and avoidance of irrigation near the foundation also help to avoid ex- cessive wetting of backfill soils, which can lead to increased backfill settlement DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 10 and possibly to higher lateral earth pressures, due to increased weight and re- duced strength of the backfill. We recommend the following precautions. 1. The ground surface surrounding the exterior of the residence should be sloped to drain away from the building in all directions. We recommend a minimum constructed slope of at least 12 inches in the first 10 feet (10 percent) in landscaped areas around the resi- dences, where practical. 2. Backfill around the foundation walls should be moistened and com- pacted pursuant to recommendations in the Foundation Wall Back- fill section. Roof downspouts and drains should discharge well beyond the lim- its of all backfill. Splash blocks and/or extensions should be pro- vided at all downspouts so water discharges onto the ground be- yond the backfill. We generally recommend against burial of down- spout discharge. Where it is necessary to bury downspout dis- charge, solid, rigid pipe should be used, and it should slope to an open gravity outlet. 4. Irrigation should be limited to the minimum amount sufficient to maintain vegetation; application of more water will increase likeli- hood of slab and foundation movements. Landscaping should be carefully designed and maintained to minimize irrigation. Plants placed close to foundation walls should be limited to those with low moisture requirements. Irrigated grass should not be located within 5 feet of the foundation. Sprinklers should not discharge within 5 feet of the foundation. Plastic sheeting should not be placed be- neath landscaped areas adjacent to foundation walls or grade beams. Geotextile fabric will inhibit weed growth yet still allow natu- ral evaporation to occur. CONCRETE Concrete in contact with soil can be subject to sulfate attack. We meas- ured a water-soluble sulfate concentration of 0.110 percent in a sample of the soils from our exploratory pits excavated at the site. For this level of sulfate con- centration, ACI 332-08, Code Requirements for Residential Concrete, indicates concrete shall be made with ASTM 6150 Type II cement, or an ASTM C595 or DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 11 C1157 hydraulic cement meeting moderate sulfate -resistant hydraulic cement (MS) designation. Alternative combination of cements and supplementary ce- mentations materials such as Class F fly ash, shall be permitted with accurate test records for sulfate durability. In our experience, superficial damage may occur to the exposed surfaces of highly -permeable concrete, even though sulfate levels are relatively low. To control this 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 of 6% +1- 1.5%. We recommend all foundation walls and grade beams in contact with the subsoils be damp -proofed. CONSTRUCTION OBSERVATIONS We recommend that CTL 1 Thompson, Inc. be retained to provide con- struction 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. If others perform these observations, they must accept responsibility to judge whether the recommendations in this report remain appropriate. Our experience indicates it is beneficial to projects, from economic and practical standpoints, when there is continuity between engineering consulta- tion and the construction observation and materials testing phases. STRUCTURAL ENGINEERING SERVICES CTL 1 Thompson, Inc. is a full -Service geotechnical, structural, materials, and environmental engineering firm. Our services include preparation of struc- tural framing and foundation plans. We can also design earth retention systems. DAVID RIPPY CONSTRUCTION, INC. CARNAI-IAN RESIDENCE PROJECT NO. GS06406.000-120 12 Based on our experience, CTL 1 Thompson, Inc. typically provides value to pro- jects from schedule and economic standpoints, due to our combined expertise and experience with geotechnical, structural, and materials engineering. We would like the opportunity to provide proposals for structural engineering services on your future projects. 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 rec- ommendations presented in any geotechnical evaluation should not be consid- ered risk-free and, more importantly, are not a guarantee that the interaction be- tween the soils and the proposed structure will perform as desired or intended. What the engineering recommendations presented in the preceding sections do constitute 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 purpose of providing geotechnical engineering design and construction criteria for the proposed residence. The information, conclusions, and recommendations presented herein are based upon consideration of many factors including, but not limited to, the type of structures proposed, the geologic setting, and the subsur- face 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. If the proposed project is not DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 13 constructed within three years, we should be contacted to determine if we should update this report. LIMITATIONS Our exploratory pits provide a reasonably accurate picture of subsurface conditions below the Carnahan Residence. Variations in the subsurface condi- tions not indicated by the borings will occur. Our representative should be called to observe the subexcavation process and test moisture and density of structural fill during placement. 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. If we can be of further service in discussing the contents of this report, please call. CTL 1 THOMPSON, INC. Ryan DeMars, E.I.T. Staff Engineer Reviewed by: ii'-'1 mes D. Kello vision Manag RD:JDK:ac cc: Via email to DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 14 cf) 0 1500 3000 61 SCALE: 1" - 3000' NOTE: IMAGE FROM GOOGLE EARTH • •~39z3;Courzi RUac '3t 1 SCIP David Rlppy Construction, Inc. Carnahan Rooldonco Project No. GS06406.000-120 Vicinity Map Fig. 1 0 200 400 SCALE: 1" = 400' NOTE: IMAGE FROM GOOGLE EARTH 3923 Caunly Dodd 3,1'1, t �' •!. David Hippy Constmctlon, Inc. Ca,nahan Ranrdanre Protect No. GS06406.000-120 Aerial Photograph Flg. 2 0 30 60 SCALE: 1" = 60' LEGEND: TP -1 APPROXIMATE LOCATION OF II EXPLORATORY PIT NOTE: IMAGE FROM GOOGLE EARTH David Rlppy Construction, Inc. Carnahan Residence Project No. GSO64O6.00O-120 Locations of Exploratory Pits Flg. 3 w LL 2 H a w 0 0 5 10 TP -1 TP -2 0 5 - 10 15 15 DAVID RIPPY CONSTRUCTION, INC. CARNAHAN RESIDENCE PROJECT NO. GS06406.000-120 IF LEGEND: LEGEND: .r. /0 LC) NOTES: TOPSOIL, CLAY, SANDY, MOIST, LIGHT BROWN. CLAY, SILTY, SANDY, MEDIUM STIFF, MOIST, LIGHT BROWN. (CL, CL -ML) INDICATES BULK SAMPLE OF EXCAVATED SOILS. 1. EXPLORATORY PITS WERE EXCAVATED WITH A BACKHOE ON OCTOBER 8, 2019. 2. GROUND WATER WAS NOT FOUND IN OUR PITS AT THE TIME OF EXCAVATION. PITS WERE BACKFILLED IMMEDIATELY AFTER EXPLORATORY EXCAVATION OPERATIONS WERE COMPLETED. 3. LOCATIONS OF EXPLORATRY PITS ARE APPROXIMATE. 4. EXPLORATORY PITS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS CONTAINED IN THIS REPORT. Summary Logs of Exploratory Pits FIG. 4 SLOPE PER OSHA COVER ENTIRE WIDTH OF GRAVEL WITH NON -WOVEN GEOTEXTILE FABRIC (MIRAF1 140N OR EQUIVALENT) SLOPE PER REPORT BACKFILL, PREFABRICATED DRAINAGE COMPOSITE 2-3' (MIRADRAIN 8000 OR EQUIVALENT) ATTACH PLASTIC SHEETING TO FOUNDATION WALL • • MI a m owe1 2' MINIMUM 8" MINIMUM — t OR BEYOND I 1:1 SLOPE FROM BOTTOM OF FOOTING (WHICHEVER IS GREATER) 4 -INCH DIAMETER PERFORATED RIGID DRAIN PIPE. THE PIPE SHOULD BE PLACED IN A TRENCH WITH A SLOPE OF AT LEAST 1/8 -INCH DROP PER FOOT OF DRAIN. .5 BELOW -GRADE WALL SUP JOINT AagqiBE4 ENCASE PIPE IN 1/2" TO 1-1/2" WASHED GRAVEL. EXTEND GRAVEL LATERALLY TO FOOTING AND AT LEAST 1/2 HEIGHT OF FOOTING. FILL ENTIRE TRENCH wrni GRAVEL FOOTING OR PAD NOTE: THE BOTTOM OF THE DRAIN SHOULD BE AT LEAST 2 INCHES BELOW BOTTOM OF FOOTING AT THE HIGHEST POINT AND SLOPE DOWNWARD TO A POSITIVE GRAVITY OUTLET OR TO A SUMP WHERE WATER CAN BE REMOVED BY PUMPING. David Rlppy Construction, Inc. Carnahan A o!dnnCo Project No. GS06406.000-120 Foundation Wall Drain Concept FIg. 5 TABLE 1 SUMMARY OF LABORATORY TESTING PROJECT NO. GS06406-120 • EXPLORATORY BORING TP -1 TP -1 TP -2 DEPTH (FEET) 4-5 7-8 9-10 ATTERBERG LIMITS L LIQUID LIMIT (%) 25 PLASTICITY INDEX (%) 8 27 1 11 SOLUBLE SULFATES (%) 0.11 PASSING NO. 200 SIEVE (%) DESCRIPTION 58 JCLAY, SILTY, SANDY (CL -ML) 64 CLAY, SANDY (CL) CLAY, SANDY (CL) Page 1 of 1