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HomeMy WebLinkAboutSoils Report 09.24.2020September 24, 2020 Andrea and Rolland Luplow c/o Stryker/Brown Architects 225 N. Mill Street, Suite 100 Aspen, CO 81611 Attention: David Brown CTL I THOMPSON Subject: Preliminary Geotechnical Evaluation Geotechnical/Geo-structural Engineering Consultation Luplow Residence 5354 County Road 100 Garfield County, Colorado Project No. GS06483.000-145 CTL/Thompson, Inc. performed a geotechnical investigation on the subject property, addressed as 5354 County Road 100, prior to construction of the exist- ing residence (now the Luplow Residence) at the site under our Project No. GS04500-120 (report dated May 26, 2005). Recently, we were asked to provide geotechnical/geo-structural engineering consultation for additions that are planned to the Luplow Residence. The scope of our services was set forth in our Proposal No. GS 20-0230. The following sections describe our previous investigation and the existing residence, discuss the proposed construction, and provide our engineering opin- ions and recommendations for design. Our opinions and recommendations pro- vided in this letter are contingent upon our observations of subsoils exposed in excavations for the new construction Previous Geotechnical Engineering Investigation We investigated subsurface conditions for our previous geotechnical in- vestigation by excavating two exploratory pits at the site with a trackhoe. Sub- soils exposed the pits consisted of about 1 foot of sandy clay "topsoil" underlain by basalt boulders and cobbles in a matrix of silty to clayey sand. Boulders en- countered in our pits made excavation deeper 6 and 7 feet not practical. Free ground water was not observed in the exploratory pits. Based on site and subsurface conditions, we recommended constructing the residence on footing foundations supported by the undisturbed, natural soil. At the time of our previous investigation, structural fill as thick as 10 to 12 feet was anticipated below the garage building. We judged footings for the garage 1 ANDREA & ROLLAND LUPLOW LUPLOW RESIDENCE PROJECT NO. GS06483.000-145 could be supported on the structural fill, provided it was in accordance with rec- ommendations in the SITE EARTHWORK section of our report. Good perfor- mance of slab -on -grade floors was anticipated. A copy of our geotechnical engi- neering investigation report is attached as Appendix A. Existing Residence James Kellogg, P.E. of CTL met at the site with David Brown of Stryker/Brown Architects on September 10, 2020. The Luplow Residence is con- structed in an area that was graded with a cut/fill balance. Excavation cut areas are at the east side of the residence. A fill embankment is along the north edge of the building site. The residence is comprised of two, wood -frame buildings that are connected by an exterior stairway/entry area. An aerial photograph of the site and exiting residence is below. Aerial photograph of site and existing residence The main residence is a one and two-story building with a crawlspace be- low the main level floor. The garage is a two-story structure that is northwest of the main residence. Garage space with a slab -on -grade floor is in the lower level. A carport area is adjacent to the north side of the garage. Column sup- ports for the carport roof are supported on pier foundations that are bottomed in the natural soils below the fill. Our cursory observations indicated the building has performed well without significant differential movement. ANDREA & ROLLAND LUPLOW LUPLOW RESIDENCE PROJECT NO. OS06483.000.145 2 Proposed Construction During our site visit, the proposed additions to the Luplow Residence were discussed. The primary addition will be a master bedroom wing east of the exist- ing residence. The new structure will attach to north side of the existing building near the main entrance. Plans by Stryker/Brown Architects (dated August 18, 2020) indicate this addition will be one-story with a crawlspace below. The addi- tion area includes previously -graded lawn and landscaping, as well as undis- turbed terrain. A photograph of the area where the master bedroom addition will connect to the existing entrance area is below. I[ ... . . Existing main entrance area viewed from east Numerous basalt boulders were observed at the ground surface adjacent to the landscaped lawn that is south and east of the existing residence. The boulders are representative of the clast-supported rocks that will be encountered in excavations at the site. Relatively difficult excavation should be expected. A 4 to 6 -inch leveling course of densely -compacted, aggregate base course may fa- cilitate construction of footings. A significant percentage of the excavated soils will not likely be suitable as foundation backfill. A photograph of conditions east of the existing residence is below. ANDREA & ROLLAND LUPLOW LUPLOW RESIDENCE PROJECT NO. GS06483.000-145 3 Proposed area of master bedroom addition viewed from north An enclosed storage room is planned at the location of the existing car- port. The west part of the carport will be enclosed, utilizing the existing roof and new wood -frame walls. A slab -on -grade floor will be constructed for the storage area. A photograph of existing conditions in the storage area is below. Proposed location of storage area addition viewed from west ANDREA & ROLLAND LUPLOW LUPLOW RESIDENCE PROJECT NO. GS06483.000-145 4 The area of the existing carport is on fill that appears to be at least 10 feet thick. This fill has been in place for nearly 15 years and the majority of consoli- dation settlement has occurred. We did not observe evidence of significant set- tlement -related damage to the garage and carport structure. The columns that support the carport roof are not founded on the fill soils. Engineering Opinions and Recommendations We recommend constructing the master bedroom addition on a footing foundation supported by the undisturbed, natural soils. A construction joint should be considered between the addition and the existing residence. Plans in- dicate a crawlspace will be below the addition floor. A foundation wall drain should be constructed around the perimeter of the crawlspace. A slab -on -grade floor is a reasonable alternative for the storage room. We suggest a turned -down edge to support the new walls and protect against potential subsoil freezing. Performance of foundations and slabs will be influenced by moisture con- ditions within the near -surface soils. The ground surface surrounding the exterior of the residence will need to be sloped to drain away from the building in all di- rections. We recommend the building be provided with roof gutters and down- spouts. Roof downspouts and drains should discharge well beyond the limits of all foundation backfill soils. In our opinion, the recommended design and construction criteria in our previous geotechnical engineering investigation report are appropriate for the proposed additions. The attached report should be referenced for structural de- sign. Our opinions and recommendations are contingent upon our observation of the subsoils exposed in excavations for the new construction. We believe this consultation was provided with that level of skill and care ordinarily used by ge- otechnical engineers practicing in this area at this time. No warranty, express or implied, is made. If we can be of further service in discussing the contents of this letter, please call. TL I THOMPSON, INC. c 4,_,\ 0 R(G jis '0 elcp o. Ice oiela , F. mes D. Kellogg, P:�` 38298 0a 'vision Manager ,62417.0 SIA t ANDREA 8 ROLLAND LUPLOW LUPLOW RESIDENCE PROJECT NO. GS06463.000-145 5 APPENDIX A PREVIOUS GEOTECNICAL ENGINEERING INVESTIGATION CTL PROJECT NO. GS04500-120 ANDREA & ROLLAND LUPLOW LUPLOW RESIDENCE PROJECT NO. GS064B3.000.145 A-1 CTLITHONdPSOP➢ SOILS AND FOUNDATION INVESTIGATION BROWN RESIDENCE LOT 4, WEST RIMLEDGE GARFIELD COUNTY, COLORADO Prepared For: STRYKER BROWN ARCHITECTS 119 South Spring Street Aspen, CO 81611 Attention: Mr. David Brown Project No. GS04500-120 May 26, 2005 234 Center Drivel Glenwood Springs, Colorado 81601 TABLE OF CONTENTS SCOPE 1 SUMMARY OF CONCLUSIONS 1 SITE CONDITIONS 2 PROPOSED CONSTRUCTION 2 SUBSURFACE CONDITIONS 3 SITE EARTHWORK 3 FOUNDATIONS 4 SLABS -ON -GRADE 5 BELOW -GRADE CONSTRUCTION 6 SURFACE DRAINAGE 7 LIMITATIONS 8 FIGURE 1 - SITE PLAN FIGURE 2 -APPROXIMATE LOCATIONS OF EXPLORATORY PITS FIGURE 3 -SUMMARY LOGS OF EXPLORATORY PITS FIGURE 4 - GRADATION TEST RESULTS FIGURE 5 - EXTERIOR FOUNDATION WALL DRAIN STRYKER BROWN ARCHITECTS BROWN RESIDENCE PROJECT NO. GSO4500-720 SCOPE This report presents the results of our geotechnical investigation for the Brown Residence proposed on Lot 4, West Rimledge in Garfield County, Colorado. We conducted this investigation to evaluate subsurface conditions at the site and provide geotechnical recommendations for the proposed construction. Our report was prepared from data developed from observation of subsurface conditions exposed in exploratory pits, engineering analysis and our experience with similar conditions. This report includes a description of the subsurface conditions observed in the exploratory pits, and presents our engineering opinions and recommendations for design and construction of foundations slab -on -grade, foundation walls, and details influenced by the subsoils. Recommendations contained in this report were developed based on our understanding of the planned construction. If plans differ significantly from the descriptions contained in the report, we should be informed so that we can provide geotechnical input and check that our recommendations and design criteria are appropriate. A summary of our conclusions is presented below. SUMMARY OF CONCLUSIONS 1. Subsurface conditions observed in the exploratory pits consisted of about 1 foot of sandy clay "topsoil" underlain by basalt boulders and cobbles in a matrix of silty to clayey sand. Practical trackhoe refusal occurred on boulders at depths of 6 and 7 feet in our pits. Free ground water was not observed in the exploratory pits. 2. We anticipate excavations at this site will be more difficult than usual due to the dense cobbles and boulders. Voids resulting from removal of Targe boulders should be filled with 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 excavated soils that are unsuitable for reuse as fill and backfill. 3. We recommend constructing the Brown Residence on footing foundations supported by the undisturbed, natural soil. Footings for the detached garage can be supported on densely compacted, granular structural fill that is placed and compacted as recommended in the report. The structural engineer should evaluate the need for a construction joint between the residence and garage. Design and construction criteria for footings are presented in the report. STRYKER BROWN ARCHITECTS BROWN RESIDENCE PROJECT NO. GS04500-120 1 4. We expect slab -on -grade construction can be supported by the densely compacted, granular structural fill with low risk of differential movement, provided the fill is placed as recommended in the report. Additional discussion is in the report. 5. Surface drainage should be designed to provide for rapid removal of surface water away from the residence. An exterior foundation wall drain should be constructed around below -grade areas in the building. SITE CONDITIONS The site is located in West Rimledge Subdivision in Garfield County, Colorado. Access to the site is from Rimledge Road. The building envelope is located in the south part of the lot (see Figure 1). Ground surface in the building envelope slopes moderately down to the northwest. Native vegetation on the property consists predominantly of pinion, juniper and sage. Numerous basalt boulders and cobbles are exposed at the ground surface. Prior to subsurface investigation, the excavation contractor constructed the driveway and cleared vegetation from the building footprint. PROPOSED CONSTRUCTION The Brown Residence is planned in the southwest part of the building envelope. The residence will be a one-story, wood -frame building at the location shown on Figure 2. A two-story, detached garage will be northwest of the residence. A crawl space will be below the floor in the residence. A breezeway will connect the house to the garage. The garage is planned as a slab -on -grade. Maximum foundation excavation depths will likely be about 6 feet. Completed wall backfill depth may be slightly more than excavation depth as final grades are adjusted for drainage. Structural fill on the order of 10 to 12 feet thick will be required below the garage to construct the building at planned elevations. Foundation Toads are expected to vary between 1,000 and 3,000 pounds per lineal foot of foundation wall with maximum interior column Toads of 30 kips. If construction will differ significantly from the descriptions above, we should be informed so that we can provide geotechnical input and adjust our recommendations and design criteria, if necessary. STRYKER BROWN ARCHITECTS BROWN RESIDENCE PROJECT NO. GS04500-120 2 SUBSURFACE CONDITIONS We investigated subsurface conditions at the site by excavating two exploratory pits (TP -1 and TP -2) at the approximate locations shown on Figure 2. The trackhoe was provided by the client's excavation contractor. Exploratory excavation operations were directed by our field representative who logged conditions exposed in the pits and obtained samples of the excavated soils. Graphic logs of the soils observed in the exploratory pits are shown on Figure 2. Subsurface conditions observed in the exploratory pits consisted of about 1 foot of sandy clay "topsoil" underlain by basalt boulders and cobbles in a matrix of silty to clayey sand. Practical trackhoe refusal occurred on boulders at depths of 6 and 7 feet in our pits. Observations during exploratory excavation indicated that the boulders and cobbles are dense to very dense. Free ground water was not observed in our exploratory pits. Results of gradation testing are shown on Figure 4. SITE EARTHWORK Structural fill as thick as 10 to 12 feet will be required below the garage and below parts of the driveway. Areas that will receive fill should be stripped of vegetation, organic soils and debris. The on-site soils free of organic matter, debris and maximum rock size of 6 inches can be used as fill outside the building footprint. We recommend that structural fill placed below the building consist of an aggregate base course such as an AASHTO Class 4 aggregate base course or similar soil. A sample of the desired import structural fill soil should be submitted to our office for approval, prior to hauling. Fill and structural fill should be placed in thin, loose lifts of 10 inches thick or less and moisture conditioned to within 2 percent of optimum moisture content. Site grading fill should be compacted to at least 95 percent of standard Proctor (ASTM D 698) maximum dry density. Structural fill should be compacted to at least 100 percent STRYKER BROWN ARCHITECTS BROWN RESIDENCE PROJECT NO. GS04500-120 3 of ASTM D 698 maximum dry density. Moisture content and density of fill and structural fill should be checked by a representative of our firm during placement. We anticipate excavations at this site for the building and underground utilities will be more difficult than usual due to the dense cobbles and boulders. Heavy-duty excavation equipment will be necessary. 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 large boulders should be filled with densely compacted, granular structural fill. Excavation sides will need to be sloped or braced to meet local, state and federal safety regulations. We believe the natural gravel and cobble soil will classify as a Type C soil based on OSHA standards governing excavations. Temporary slopes deeper than 5 feet should be no steeper than 1.5 to 1 (horizontal to vertical) in Type C soils. Contractors should identify the soils encountered in the excavations and refer to OSHA standards to determine appropriate slopes. Free ground water was not observed in our exploratory pits. We do not anticipate excavations for foundations or utilities will penetrate ground water, however, excavations should be sloped to a gravity discharge or to a temporary sump where water can be removed by pumping. The ground surrounding the excavations should be sloped to direct runoff away from the excavations. FOUNDATIONS We recommend constructing the Brown Residence on footing foundations supported by the undisturbed, natural soil. Voids resulting from removal of large boulders should be filled with densely compacted, granular structural fill. The completed foundation excavation should be observed by a representative of our firm, prior to placing forms, to confirm that the subsoils are as anticipated and suitable for support of the designed footings. Footings for the detached garage can be supported on densely compacted, granular structural fill. Recommendations for structural fill were presented in the SITE EARTHWORK section. STRYKER BROWN ARCHITECTS BROWN RESIDENCE PROJECT NO. GS04500-120 4 We expect the structural fill will consolidate about 1 percent of the total fill thickness. Less settlement will occur for the main residence footings supported on the undisturbed, natural soils. The structural engineer should evaluate the need for a construction joint between the residence and the garage. Recommended design and construction criteria for footings are presented below. 1. Footing foundations should be supported by the undisturbed, natural soils or densely compacted granular, structural fill. Soils loosened during excavation or the forming process for the footings should be removed or the soils can be re -compacted prior to placing concrete. 2. Footings should be designed for a maximum allowable soil pressure of 3,000 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 required, depending upon foundation loads. 4. Grade beams and foundation walls should be well reinforced, top and bottom, to span undisclosed loose or soft soil pockets. We recommend reinforcement sufficient to span an unsupported distance of at least 10 feet. Reinforcement should be designed by the structural engineer. 5. The soils beneath exterior footings should be protected from freezing. We recommend the bottom of footings be constructed at a depth of at least 36 inches below finished exterior grades for frost protection. SLABS -ON -GRADE The floor in the parking level of the garage is planned as a slab -on -grade. We judge slab -on -grade construction can be supported by the densely compacted, granular structural fill with low risk of differential movement, provided the structural fill placed is placed in accordance with the recommendations outlined in the SITE EARTHWORK section. Settlement of about 1 percent of the total fill thickness should be anticipated. STRYKER BROWN ARCHITECTS BROWN RESIDENCE PROJECT NO. GSO4500-120 5 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. 2. 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. 3. Exterior patio and porch slabs should be isolated from the residence. These slabs should be well -reinforced to function as independent units. 4. Frequent control joints should be provided, in accordance with American Concrete Institute (ACI) recommendations, to reduce problems associated with shrinkage and curling. Our experience indicates panels which are approximately square generally perform better than rectangular areas. BELOW -GRADE CONSTRUCTION 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. 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 which can deflect 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 basement walls can deflect or rotate slightly under normal design 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, we recommend design of below -grade walls using an equivalent fluid density of at least 50 pcf for this site. This equivalent STRYKER BROWN ARCHITECTS BROWN RESIDENCE PROJECT NO. GS04500-120 6 density does not include allowances for sloping backfill, surcharges or hydrostatic pressures. The recommended equivalent density assumes deflection; some minor cracking of walls may occur. If very little wall deflection is desired, a higher equivalent fluid density may be appropriate for design. Backfill placed adjacent to foundation wall exteriors should be free of organic matter, debris and rocks larger than 6 inches in diameter. Backfill should be moisture conditioned to within 2 percent of optimum moisture content and compacted to at least 95 percent of standard Proctor (ASTM D 698) maximum dry density. Water from rain, snow melt and surface irrigation frequently flows through relatively permeable backfill placed adjacent to a residence and collects on the surface of permeable, undisturbed soils at the bottom of the excavation. This can cause wet or moist conditions in basement and crawl space areas after construction. To reduce the likelihood water pressure will develop outside foundation walls and reduce risk of accumulation of water in the crawl space, we recommend provision of a foundation drain. The drain should consist of a 4 -inch diameter, open joint or slotted pipe encased in free draining gravel. The drain should lead to a positive gravity outfall, or to a sump pit where water can be removed by pumping. A typical foundation drain detail is presented on Figure 4. SURFACE DRAINAGE Surface drainage is critical to the performance of foundations, floor slabs and concrete flatwork. We recommend the following precautions be observed during construction and maintained at all times after the residence is completed: 1. The ground surface surrounding the exterior of the residence should be sloped to convey surface water away from the building. We recommend providing a slope of at least 6 inches in the first 5 feet around the residence, where possible. 2. Backfill around the exterior of foundation walls should be placed in maximum 10 inch thick loose lifts, moisture conditioned to within 2 percent of optimum moisture content and compacted to at least 95 percent of standard Proctor (ASTM D 698) maximum dry density. STRYKER BROWN ARCHITECTS 7 BROWN RESIDENCE PROJECT NO. GS04500-120 3. The building should be provided with roof gutters and downspouts. Roof downspouts and drains should discharge well beyond the limits of all backfill. Splash blocks and downspout extensions should be provided at all discharge points. 4. Landscaping should be carefully designed to minimize irrigation. Plants used near 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 and should be directed away from the building. 5. Impervious plastic membranes should not be used to cover the ground surface immediately surrounding the residence. These membranes tend to trap moisture and prevent normal evaporation from occurring. Geotextile fabrics can be used to control weed growth and allow some evaporation to occur. LIMITATIONS The exploratory pits provide a reasonably accurate picture of subsurface conditions at the site. Variations in the subsurface conditions not indicated by the pits will occur. We should observe the completed foundation excavation to confirm that the soils are as anticipated and suitable for support of the footings as designed. This investigation was conducted in a manner consistent with that level of care and skill ordinarily exercised by engineering geologists and geotechnical engineers currently practicing under similar conditions In the locality of this project. No other warranty, express or implied, is made. If we can be of further service in discussing the contents of this report, please call. CTL ( THOMPSON, INC. James D. Kellogg, P.E. Project Engineer JDK:cd (5 copies sent) STRYKER BROWN ARCHITECTS BROWN RESIDENCE PROJECT NO. GS04500.120 8 IF Stryker Brown Architects Lot 4, West Rkn Ledge Protect No. 0804500-120 Site Plan Flg. 1 SCALE: 1 •= 30' UeztdI phone r_ ► elect is Stryker Brown Architects Lot 4, west Rin Ledge Project No. GS04500-120 Approximate Locations of Exploratory Pits Fig. 2 1 Projaut No. 0504500-120 TP -1 ELa6771 TP -2 EL -6756 -- 6775 6775 — — 6770 6770 6765 6765 — 6760 — 6755 L — 6750 6745 6760 J 6755 — 6750- - 6745 --' LEGEND Sandy clay-topnon v rgorice, roots, Cobble], molrl, .fork brown. EgBasan boulders and cobbles. matrix of silty to Clayey sand. pockets of sandy ally. slightly moist. light brown. dark gray. 111 T NOTES; Indlaales bulk sample. Indicates practical trookhee r.fuam. 1. Exploratory pHs were excavated with a Irackhoe on May 5, 7pO5. Pile were hockflIled Immedlofnly after excavation oporafons were aamplstsd. 2. No free ground water was observed In the exploratory pits al the time of excovo+ion. 3. Lacalionn and elevollone nl exploratory pits an approximate. 4. rheas exp!crofory pits are adbJocl Po Inn expiarlation=, IfmIteliona and ronrluatcra as contained In Nils report. SUMMARY LOGS OF EXPLORATORY PITS Fig. 3 HYDROMETER ANALYSIS SIEVE ANALYSIS 25 HR. 7 HR. TV& READINGS U.S. STANDARD SERIES 45 MIN. 15 MIN. 60 MW. 19 MIN. 4 MIN. 1 MN. '200 '100 '50 MO '30 '16 '10 '84 CLEAR SQUARE OPENINGS 3/6- 3/4' 114" 3' 5-6* 8' 0 .009 .019 .037 .074 .149 .297 0.42.590 1. 9 2.0 2.38 4.76 9.52 19.1 36.1 DIAMETER OF PARTICLE IN MILLIMETERS 76.2 127 200 152 CLAY (PLASTIC) TO SILT (NON -PLASTIC) GRAVEL FINE / MEDIUM / COARSE . FINE COARSE J COBBLES 1 SANDS 10 20 30 40 59 0 10 nn Sample of GRAVEL, SILTY (GM) From TP -1 AT 4-6 FEET GRAVEL 66 % SAND 17 % SILT CLAY 17 % LIQUID LIMIT - % PLASTICITY INDEX - HYDROMETER ANALYSIS SIEVE ANALYSIS 25 HR. 7 HR. TIME READINGS U.S. STANDARD SEA& 45 MIN. 15 MIN. 80 MIN. 19 MIN. 4 MIN. 1 MIN. '200 '100 '50 '40 '30 '16 '10 8 100 90 80 70 I 60 N 40 30 20 10 0 001 0.002 .......... ........ ........... • 1. l.. .1 ... . — .. i.--2 ...— .... L ..... "t: .. L. *_...._.r::::.:... ';:::) ......... 3/8' CLEAR SODARE OPENINGS 3/4' 1W 3' 5-6' 8' ,0 .. ..... ' • ....-.... ... ....... ........... ..... ..... „ ......... .:••••••• ......:2:,::: 4 10 20 30 Ii z 40 50 0) 60 70 80 90 100 .005 .009 .019 .037 .074 .149 .297 0.42.590 1.19 2.0 2.38 4.76 9.52 19.1 36.1 76.2 127 200 152 DIAMETER OF PARTICLE IN MILLIMETERS CLAY (PLASTIC) TO SILT (NON•PLAST1C) SANDS GRAVEL FINE 1 MEDIUM COARSE FINE / COARSE ./ COBBLES Sample of GRAVEL, SILTY (GM) From TP -2 AT 5-7 FEET PROJECT NO. GS04500-190 GRAVEL 68 % SAND 21 % &LT & CLAY 11 % LIQUID LIMIT -% PLASTICITY INDEX Gradation Test Results FIG.4 . ...... ........_. .—. ................. ._.__..___.. • ..........._.... I r _..___ ........ ..........—....--.-....." —................ . 1 j 1 • '-r". ............•••• ,........... :1.. ;. .., .. ..r M 0 •................ ....... r.. I ....... .....• ±:::....... .... 1.....-:'.- ••••-•-• • ........ ... .... ... ....... .......44 . . .............1 • .-.-...-•• _...............____—...—.. ..... ..... r ..... . .. . ..- ..... • z c... ....... . .r ''::::::"" .. ....... • _ : it..- ...— ...—.... : ...........—.. ..... " ---- " ........ -... ....—.... .,.1 —.—... ..."...."...."....'—.".1 _ ..............._........—..... ,1... .:._...:._.:..Jtr•— t' - :...,........ - .— ....... — — — — — — ... .::..:—::: ............. .. ................. ...... — .... _ ............ ....____„..,....— .... — ....... ..... _, • 1 • '—"'"...:::=--- :::: I . .. ........ _._ ................. ...—....— — ...... ...... I s. .009 .019 .037 .074 .149 .297 0.42.590 1. 9 2.0 2.38 4.76 9.52 19.1 36.1 DIAMETER OF PARTICLE IN MILLIMETERS 76.2 127 200 152 CLAY (PLASTIC) TO SILT (NON -PLASTIC) GRAVEL FINE / MEDIUM / COARSE . FINE COARSE J COBBLES 1 SANDS 10 20 30 40 59 0 10 nn Sample of GRAVEL, SILTY (GM) From TP -1 AT 4-6 FEET GRAVEL 66 % SAND 17 % SILT CLAY 17 % LIQUID LIMIT - % PLASTICITY INDEX - HYDROMETER ANALYSIS SIEVE ANALYSIS 25 HR. 7 HR. TIME READINGS U.S. STANDARD SEA& 45 MIN. 15 MIN. 80 MIN. 19 MIN. 4 MIN. 1 MIN. '200 '100 '50 '40 '30 '16 '10 8 100 90 80 70 I 60 N 40 30 20 10 0 001 0.002 .......... ........ ........... • 1. l.. .1 ... . — .. i.--2 ...— .... L ..... "t: .. L. *_...._.r::::.:... ';:::) ......... 3/8' CLEAR SODARE OPENINGS 3/4' 1W 3' 5-6' 8' ,0 .. ..... ' • ....-.... ... ....... ........... ..... ..... „ ......... .:••••••• ......:2:,::: 4 10 20 30 Ii z 40 50 0) 60 70 80 90 100 .005 .009 .019 .037 .074 .149 .297 0.42.590 1.19 2.0 2.38 4.76 9.52 19.1 36.1 76.2 127 200 152 DIAMETER OF PARTICLE IN MILLIMETERS CLAY (PLASTIC) TO SILT (NON•PLAST1C) SANDS GRAVEL FINE 1 MEDIUM COARSE FINE / COARSE ./ COBBLES Sample of GRAVEL, SILTY (GM) From TP -2 AT 5-7 FEET PROJECT NO. GS04500-190 GRAVEL 68 % SAND 21 % &LT & CLAY 11 % LIQUID LIMIT -% PLASTICITY INDEX Gradation Test Results FIG.4 SLOPE PER REPORT SUPPORTED BELOW GRADE WALL SLOPE PER OSHA BACKFILL (CQMPOSfTION AND COMPACTION PER REPORT) ENCASE PIPE IN WASHED _ CONCRETE AGGREGATE (ASTM C33, NO. 57 OR NO. 67) EXTEND GRAVE TO AT LEAST 1/2 HEIGHT OF FOOTING. Project No. 0S04500-120 COVER GRAVEL WITH FILTER FABRIC SLOP[ TD ORAN 2" MINIMUM f 8" MINIMUM OR BEYOND 1:1 SLOPE FROM BOTTOM OF FOOTING. (WHICHEVER IS GREATER) 4 -INCH DIAMETER PERFORATED DRAIN PIPE. THE PIPE SHOULD BE PLACED IN A TRENCH WITH A SLOPE RANGE BETWEEN 1/8 INCH AND 1/4 INCH DROP PER FOOT OF DRAIN. - PROVIDE PVC SHEETING GLUED TO FOUNDATION WALL TO REDUCE MOISTURE PENETRATION. REINFORCED STEEL PER STRUCTURAL DRAWINGS - CRAWL SPACE-) -- FOOTING OR PAD BUrroM OF EXCAVATION NOTE: 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. Exterior Foundation Wall Drain Fig. 5