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HomeMy WebLinkAboutSoils & Foundation Investigation 8.22.07T CTLITHOMPSON SOILS AND FOUNDATION INVESTIGATION MILLER RESIDENCE PARCEL 3, ROE SUBDIVISION GARFIELD COUNTY, COLORADO Prepared For: MR. JOHN MILLER 405 Will Avenue Rifle, CO 81650 Project No. GS05048-120 234 Center Drive I Glenwood Springs, Colorado 81601 Telephone: 970-945-2809 Fax: 970·945-7411 August 22, 2007 1 't . ' ·~ TABLE OF CONTENTS SCOPE 1 SUMMARY OF CONCLUSIONS 1 SITE CONDITIONS 2 PROPOSED CONSTRUCTION 2 SUBSURFACE CONDITIONS 2 SITE EARTHWORK 3 Excavations 3 Sub-Excavations 4 Fill and Backfill 5 FOUNDATIONS 5 Friction Piers 6 Footing Foundations on Structural Fill 7 FLOOR SYSTEM AND SLAB-ON-GRADE CONSTRUCTION 8 BELOW-GRADE CONSTRUCTION 9 SURFACE DRAINAGE 11 LIMITATIONS 12 FIGURE 1-APPROXIMATE LOCATIONS OF EXPLORATORY BORINGS FIGURE 2 -SUMMARY LOGS OF EXPLORATORY BORINGS FIGURES 3 AND 4-SWELL-CONSOLIDATION TEST RESULTS FIGURES 5 AND 6 -EXTERIOR FOUNDATION WALL DRAINS TABLE I -SUMMARY OF LABORATORY TEST RESULTS JOHN MILLER MILLER RESIDENCE CTLIT PROJECT NO. GS05048·120 S:IGS05041.000\12012. Reporu\GS05D41120 RI.doc .. SCOPE This report presents the results of our soils and foundation investigation for the proposed Miller Residence on Parcel 3 of the Roe Subdivision in Garfield County, Colorado. We conducted the investigation to evaluate the subsurface conditions at the site and provide geotechnical engineering recommendations for the proposed construction. Our report was prepared from data developed from our exploratory borings, laboratory testing, engineering analysis, and experience with similar conditions. This report includes a description of the subsurface conditions found in our exploratory borings drilled at the site and presents recommendations for design and construction of foundations, floor systems, below-grade walls, subsurface drains, and criteria for details influenced by the subsoils. A summary of our conclusions is presented below. SUMMARY OF CONCLUSIONS 1. Subsurface conditions encountered in our exploratory borings consisted of 0.5 feet of sandy clay "topsoil" underlain by sandy clay to the maximum explored depth of 30 feet below existing ground surface. An approximately 3 foot lense of clayey gravel was encountered in our exploratory boring TH-2 at an approximate depth of 9 feet below existing ground surface. Laboratory test results and our experience indicate the sandy clay under the subject parcel possesses potential for moderate to high amounts of expansion when wetted under foundation loads. Free ground water was not found in our exploratory borings during drilling operations. 2. Differential heave and associated damage to foundations and floor slabs is likely if the proposed residence is constructed directly on the undisturbed, natural sandy clay. We recommend constructing the residence on a drilled pier foundation that is below the probable depth of wetting. A less positive alternative Is to construct the residence on footing foundations supported on a minimum 3 foot thick layer of structural fill. Design and construction criteria for drilled piers and footings on structural fill are presented in the report. 3. In our opinion, lower level floors In living areas of the residence should be structurally supported by the foundation system. We recommend sub-excavation, moisture-treatment and recompaction of soils to a JOHN MILLER MILLER RESIDENCE CTLIT PROJECT NO. GS05048·120 S:IGS05D48.0001120\2. RoportslGS05048 120 R1.doc 1 , ' depth of at least 2 feet below floor slabs in unfinished areas such as the garage. 4. Surface drainage should be designed to provide for rapid removal of surface water away from the proposed residence. A foundation drain should be Installed around the basement SITE CONDITIONS The Roe Subdivision is a development located approximately 6 miles south of Rifle on County Road 319 in Garfield County, Colorado. Parcel 3 ls In the western part of the subdivision. Parcel 4, which is east of Parcel 3, is developed with a slngle- family residence and a detached garage. Ground surfaces on the parcel slope down to the south at grades between 5 and 1 O percent Vegetation on the parcel consisted of sage brush and pine and juniper trees. PROPOSED CONSTRUCTION Building plans were not provided to us. We understand the residence will likely be a two-story, wood.frame building ~ith a basement and an attached garage. Maximum foundation excavation depths of about 10 to 12 feet are expected at the uphill side of the building. Garage floors in similar residences in the area are typically constructed as slabs-on-grade. We expect maximum foundation wall loads of about 3,000 pounds per lineal foot offoundation wall and maximum column loads of 30 kips. If actual construction will differ significantly from the descriptions above, we should be informed so that we can provide geotechnical input and revise our recommendations, if necessary. SUBSURFACE CONDITIONS Subsurface conditions for the Miller Residence were investigated by drilling two exploratory borings (TH-1 and TH-2) with a track-mounted drill rig at the approximate locations shown on Figure 1. Drilling operations were directed by our staff engineer who logged the soils encountered in the borings and obtained samples JOHN MILLER MILLER RESIDENCE CTI.IT PROJECT NO. GS05048· 120 S :IOSOI041.000112012. RtponalGS05041120 R1 .doc 2 'I ·, for testing in our laboratory. Graphic logs of the soils found in our exploratory borings are shown on Figure 2. Subsurface conditions encountered in our exploratory borings consisted of about 0.5 feet of sandy clay "topsoil" underlain by sandy clay to the maximum explored depth of 30 feet below existing ground surface. An approximately 3 foot lense of clayey gravel was encountered in exploratory boring TH-2 at an approximate depth of 9 feet below existing ground surface. Results of field penetration resistance tests and our observations during drilling indicated thatthe gravel was dense and the clay was very stiff. Free ground water was not found in our exploratory borings during drilling operations. Samples obtained in the field were returned to our laboratory where field classifications were checked and samples were selected for pertinent testing. Three samples of the natural sandy clay were selected for one-dimensional, swell- consolldation testing. During the test procedure the samples were loaded with 1,000 psf and then flooded. The resulting volume change (i.e., swell or consolidation} was then measured. The clay samples tested exhibited between 0.4 to 3.3 percent swell. The samples were then loaded back to the original volume to determine the swell pressures. Results of swell-consolidation testing are shown on Figures 3 and 4. Laboratory test results are summarized on Table I. SITE EARTHWORK Excavations We anticipate excavations for foundations and utilities at this site can be accomplished using conventionalt heavy-duty excavation equipment Excavation sides will need to be sloped or braced to meet local. state and federal safety regulations. The natural, sandy clay will likely classify as a Type 8 soil, and the gravel as a Type C soil based on OSHA standards governing excavations. Temporary slopes deeper than 4 feet should be no steeper than 1 to 1 (horizontal to vertical} in Type B JOHN MILLER Mil.I.ER RESIDENCE CTI..jT PROJECT NO. GS05048·120 S :\GSOI0'8.C00\12012. RoportalGSOS041120 R1.doc 3 . , soils and 1.5 to 1 in Type C soils. Contractors should identify the soils encountered in excavations and refer to OSHA standards to determine appropriate slopes. Contractors are responsible for proper site excavation and the maintenance and safety of the excavations and overall site safety. Free ground water was not found in our exploratory borings during this investigation. We do not anticipate excavations for foundations or utilities will penetrate ground water. Excessive wetting of the excavation should be avoided. Excavations should be sloped such that water from precipitation can drain to a positive gravity outfall or to a temporary sump where water can be removed by pumping. Ground surfaces surrounding excavations should be sloped as much as practical to direct runoff away from the excavations. Sub-Excavation Laboratory test results and our experience at the site indicate the natural, sandy clay below the subject lot possess the potential for moderate to very high amounts of expansion when wetted. Differential heave and associated damage to floor slabs is likely if the slabs are constructed directly on the natural clays. As discussed in the SLAB-ON-GRADE section, we recommend removal {i.e. sub-excavation), moisture-treatment and recompaction of the soils below the floor slabs in unfinished areas such as the garage. Sub-excavation should be to a depth of at least 2 feet below the bottom of slabs. Sub-excavation of at least 12-inches would enhance performance of exterior slabs. Sub-excavated areas below slabs should extend laterally at least 1.5 feet beyond the perimeter of the slabs. The bottom of the sub-excavated area should be scarified to a depth of at least 8 inches, moisture- treated and compacted. We recommend re-using the excavated soils for structural fill, provided they are free of organics, debris and rocks larger than 4 inches In diameter. If import soils are required for use as structural fill, they should be similar to the on-site soils. JOHN MILLER MILLER RESIDENCE CTLIT PROJECT NO. GS05048-120 S:IGS050...000\12012. Repe>.UIGS06048 120 R1.tlo~ 4 Structural fill should be moisture-treated to between 1 percent below and 3 percent above optimum moisture content and compacted to 98 percent of standard Proctor (ASTM D 698) maximum dry density. Additional water required to increase the existing soil moisture content to the specified moisture content should be uniformly mixed into the fill soil prior to compaction. We recommend a maximum loose lift thickness of 8 inches. The actual thickness of fill lift that can be properly compacted will depend on the type of compaction equipment In order for the procedure to perform properly, close control of structural fill placement to specifications is required. Our representative should be called to check processing, compaction, and moisture content of the structural fill during placement. Fill and Backfill Proper placement and compaction of fill and backfill adjacent to the building is critical to prevent infiltration of surface water and wetting of the soils below the building. The on-site soils free of organics, debris and rocks larger than 4 inches in diameter can be used as fill and backfill. If import soil is required for fill and backfill, it should have similar characteristics to the on-site soils. Fill and backfill outside the building footprint should be placed in loose lifts of B inches thick or less, moisture treated to between 1 percent below and 3 percent above optimum moisture content and compacted to 95 percent of standard Proctor (ASTM D 698) maximum dry density. We recommend that density and moisture content be checked during placement. FOUNDATIONS The natural sandy clay below the site possess potential for moderate to high amounts of expansion when wetted under foundation loads. Differential heave is likely if the Miller Residence is constructed directly on the undisturbed, natural clay soil. We recommend constructing the Miller Residence on drilled pier foundations. Piers concentrate building deadloads and anchor the foundation below the zone of probable moisture variation to resist potential swelling pressures from the expansive JOHN MILLER MILLER RESIDENCE CTllT PROJECT NO. GSOS048·120 S;IGSOS0,9,000\12012. R1parta\GS05Da 120 R1.dac 5 soil. A high degree of care will need to be taken to prevent wetting of the soils below the residence. A less positive foundation alternative is to construct the building on footing foundations, provided the soils are sub-excavated to a depth of at least 3 feet below footings, moisture-treated, and recompacted. We recommend reuse of the on-site soils as structural fill. Recommendations for sub-excavation and structural fill placement were provided in the Sub-excavation section. Recommended design and construction criteria for friction piers and footing foundations are presented below. Friction Piers 1. Piers should be designed for a maximum allowable end pressure of 8,000 psf and skin friction of 1,000 psf. Skin friction should be neglected for the upper 3 feet of pier below grade beams. 2. Piers should be designed for a minimum deadload pressure of 10,000 psf based on pier cross-sectional area. If this deadload cannot be achieved through the weight of the structure, the pier length should be Increased beyond the minimum values specified In the next paragraph. 3. Piers should have a total length of at least 20 feet. The pier length should not exceed about 30 times the pier diameter (we assume 10-inch piers will be used). 4. Piers should be reinforced their full length with at least 2 No. 7 (22 mm), Grade 60 (420 Mpa) reinforcing bars (or their equivalent) to resist tension in the event of swelling. Reinforcement should extend into grade beams and foundation walls. 5. There should be an 8-inch (or thicker) continuous void beneath all grade beams and foundation walls, between piers, to concentrate the deadload of the structure onto the piers. 6. Grade beams (If any) should be well reinforced. The reinforcement should be designed by a qualified structural engineer. Lateral earth pressures and the effects of large openings within basement walls should be considered. 7. JOHN MILLER MILLER RESIDENCE Piers should be carefully cleaned prior to placement of concrete. We recommend a "drill-and-pour" procedure for pier installation. Concrete should be ready on-site and placed in the pier holes immediately after the holes are drilled, cleaned and observed by our representative to 6 CTLIT PROJECT NO . GS05048·120 S :IGSOSCMl.000112012. RoporulGS05041120 R1,doc avoid collecting water and possible contamination of open pier holes. If ground water is encountered during pier installation, temporary casing, tremie equipment, and/or pumping may be necessary for proper cleaning, dewatering, and concrete placement. Concrete should not be placed by free fall if there is more than 3 inches of water at the bottom of the hole. 8. Concrete placed in pier holes should have sufficient slump to fill the pier hole and not hang on the reinforcement or the sides of the casing during extraction (if used). We recommend a slump in the range of 5 to 7 inches. 9. Formation of mushrooms or enlargements at the top of piers should be avoided during pier drilling and subsequent construction operations. 10. Installation of drilled piers should be observed by a representative of our firm to Identify the proper bearing strata. Footing Foundations on Structural Fill 1. Footing foundations should be supported by a minimum 3Mfoot thickness of densely compacted, structural fill. Soil loosened during the forming process should be removed or recompacted. 2. Footings on the structural fill should be designed for a maximum soil bearing pressure of 3,000 psf. 3. Continuous wail 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 12 feet. Reinforcement should be designed by the structural engineer. 5. The soils under 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. The Garfield County building department should be consulted regarding frost protection requirements. JOHN MILLER MILLER RESIDENCE CTLIT PROJECT NO. GS05048·120 S :IGSOS048.00Dl1 ~Oil. R1porta\GSIJ$04B 120R1.doc: 7 ·. FLOOR SYSTEMS AND SLAB-ON-GRADE CONSTRUCTION Expansive natural sandy clay soils are present at or near anticipated floor elevations. The expansive clay soil is stable at existing moisture contents, but upon wetting will heave lightly loaded slabs. This heaving cannot be controlled by concentrating slab loads. Some increase in moisture must be assumed because of the impact of residential construction and associated landscaping. The best current method to limit the potential floor heave, to our knowledge, is the construction of a structural floor with an air space between the floor and the subgrade soils. The required air space depends on materials used to construct the floor and local building codes. The air space should Include at least 8 inches for potential heave of expansive soils. The structural floor is supported by the foundation system. There are design and construction issues associated with structural floors, such as ventilation and increased lateral loads, which must be considered. In our opinion, structural floors should be used in all finished living areas in the proposed Miller Residence. Structural floors are not normally used in garage areas of similar residences In the area. Driveways, sidewalks and exterior patio slabs are also constructed as slabs-on-grade. Performance of slabs-on-grade on expansive soils is erratic. Various properties of the soils and environmental conditions influence magnitude of movement and other performance characteristics of slabs supported by expansive soils. Increases in the moisture content in expansive soils will cause heaving and may cause cracking of slabs-on-grade. We believe these movements are most likely in the first 3 to 5 years following construction as the soils respond to changes in availability of moisture. A less positive approach would be to construct the lower level floors as slabs- on-grade supported by a minimum 2 foot thick layer of structural fill. Guidelines for structural fill placement provided in the Sub-Excavation section should be followed. To enhance performance, we recommend sub-excavation, moisture~treatment, and recompaction of the soils to a depth of at least 2 feet below floor slabs in JOHN MILLER MILLER RESIDENCE CTLl'f PROJECT NO. GSOS048·120 S:\GSD5D41.0D0\120U. Reparta\GSD5D48 120 R1.cto; 8 unfinished areas such as the garage. We recommend a sub-excavation process to a depth at least 12 inches below exterior slabs. Recommendations in the Sub- Excavation section should be followed. The recommendations in the SURFACE DRAINAGE section will be critical to reduce potential for wetting of the subsoils below slabs. We recommend the following precautions for slab-on-grade construction at this site. These precautions will not prevent movement from occurring; rather. they tend to reduce damage if slab movement occurs. 1. We recommend against placing a sand or gravel layer below slabs. Provision of a sand or gravel layer below slabs increases the possibility of a single source of water wetting the entire area supporting the slab. 2. Slabs should be separated from exterior walls and interior bearing members with slip joints which allow free vertical movement of the slabs. 3. Underslab plumbing should be pressure tested before the slab is constructed. Plumbing and utilities which pass through slabs should be isolated from the slab with sleeves and be constructed with flexible connections to slab supported appliances. Heating and air conditioning systems supported by slabs should be provided with flexible connections capable of at least 2 inches of vertical movement so that slab movement is not transmitted to the duct work. 4. Exterior patio and porch slabs should be isolated from the residence. These slabs should be well-reinforced to function as independent units. Movements of these slabs should not be transmitted to the residence foundation. 5. 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 JOHN MILLER MILLER RESIDENCE CTLIT PROJECT NO. GS05048-120 5:1G5D5D41.DOD\12Dl2. R•pons\GS05D4112D R1.doc 9 _.. 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-restu 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 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. If on-site soils or similar 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 density does not include allowances for sloping backfill, surcharges or hydrostatic pressures. Backfill placed adjacent to foundation wall exteriors should be placed and compacted as outlined in the Fill and Backfill section. Water from precipitation, snow melt and surface irrigation of lawns and landscaping frequently flows through relatively permeable backfill placed adjacent to a residence and collects on the surface ofrelatively undisturbed soils atthe bottom of the excavation. This can cause wetting of soils below the building, hydrostatic pressure on below-grade walls, and moist conditions in below-grade areas after construction. To mitigate these concerns, we recommend provision of a foundation drain around the residence. The drain should consist of a 4-inch diameter, slotted PVC pipe encased in free draining gravel. The drain should lead to a positive gravity outfall or a sump pit where water can be removed by pumping. Typical foundation drain details are shown on Figures 5 and 6. Ventilation is important to maintain acceptable humidity levels in crawl spaces. The mechanical systems designer should consider the humidity and temperature of air, and air flow volumes, during design of crawl space ventilation systems. We JOHN MILLER MILLER RESIDENCE CTLIT PROJECT NO. GS05048·120 S:\GS05041.000\1ZOl2. Raporta1GS050'4a 1ZD Rt.doc 10 believe it is appropriate to install a ventilation system that is controlled by a humidistat. 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 Miller Residence is completed: 1. The ground surface surrounding the exterior of the residence should be sloped to drain away from the building in all directions. We recommend providing a slope of at least 6 inches in the first 5 feet around the building in landscaped areas. 2. Backfill adjacent to foundation wall exteriors should be placed and compacted as described in the Fill and Backfill section. Increasing the moisture content of backfill soil after placement often results in additional settlement of the backfill. This settlement is most common adjacent to north facing walls. 3. The residence should be provided with 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. Water from roof and surface runoff should not be introduced to the foundation drain system. 4. Landscaping should be carefully designed to mm1m1ze irrigation. Plants used near foundation walls should be limited to those with low moisture requirements; irrigated grass or other landscaping requiring comparatively large amounts of irrigation should not be located within 5 feet of the foundation. Sprinklers should be at least 5 feet from building foundations and directed away from the building. Irrigation should be limited to the minimum amount sufficient to maintain vegetation; the application of additional water will increase the likelihood of slab and foundation movements. 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. JOHN MILLER MILLER RESIDENCE CTLIT PROJECT NO. GSD5048·120 S:\GS05048.000\120U. Repons\GS05048 120 RI.doc 11 LIMITATIONS Our exploratory borings were located to obtain a reasonably accurate picture of the subsurface. Variations in the subsurface conditions not Indicated by our exploratory borings will occur. A representative of our firm should observe the sub- excavation process and installation of drilled piers. 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 implied, is made. If we can be of further service or if you have questions regarding this report, please call. CTL I THOMPSON, INC. Edward R. White, E.I. Staff Engineer Reviewed by: John Mechling, P.E. Branch Manager ERW:JM:cd (5 copies sent) JOHN MILlER MILLER RESIDENCE CTLIT PROJECT NO. GS05048-120 S:IGS05041.QDlll1 iDli. R•pon.IGS0504& 120 R1.doc 12 ; 6CAI.£: , •• 200' JannMI ... --Protect No. GS05048-1:ZO ''I ~ - I I ~ARCEL 1 70.00IJ Gi;;nlll I 1 · '\ lVC:,. -~ -l-. . ~-· """'-' -~ I l '·· r.1·&t1· ' ' . I: °:."7 //·""] -. : . * -· , .. _,,,. ,,,.,,, ... ," --c::-·~~--<~· -...--:::--f ~-;_:...~:--<> -· --• ·-' :-.::-1,>;.<:•:1 . ..-· •••. -• ' .. C.! ' . · .... \. ". ,,, .:. ~: .--,.;.)N-L"\C:. -·-• ·~\ • n·11<;,1: .... ,.;!'' .m -' I ' t >'· t.P!ILU ~<.!..l.ICl.llf M- ropOS•d o.., IT•"':"'-1~' u.~·, .. ·r~ ... 111k!: Cl"A.tr"P• 1 '' 'S ::..t-u fZ T'. ,,. ~~ ;)o -(", Ul D ..... -~ ,., ~ ~1 4'J E ill - ': 1!:.J..: ,~=· u AA..-.. ::AP '. , '~. j i .l ... .1,~··· ' .. ·~ .~ ' ' '·:·· .. . -... . :r, ,. . .. >·~ ··~/' ~· ~·,., • , "' •• p I ?. PARCEL l IJAt()g .'\ '. '\ . ' Bulldlng Sit• .IO.IAL.ARtA i 39.51 J OC"t'e!I (4'..,,.t.Ml~ ·.-.r.u.1<'~ 1.1 .. "1'.:t ~: !Jn~ rr• '' lil~Jt.(Tt:'i 1.1t ':."' C.'-.! •. rt.t(NI PARCEL 4' 10~~ ~ ~if~ ... ~h, .. ~ .... ~. ~~--'° -~~...._~~.·;, ':v~.; '•"""' ·,· _ _, .~ . "'':~. · .. ·. , ... i~·5: .-l . ,... --. .. -• • r/I: ~.lHt.'oi: • •::.:i:~ ....... t)lt .. 4'1 P•~-t:v r "'T ·'-t:r " "'· r .:·;;.-~~ . •_'.:-.. :.~\·-.. ::. . .. ~) \' ... '"· '- """"''t:• ..... lO:( ~·?r~:r·n:. \.~' .......... \:. ,,,~ .... ,. ,·--:'.,J e .. ~~~~ s. seg-~·50"\ ~ ... ~ ~ °' ~ T Approximate Location of Exploratory Borings Fig. TH-1 TH-2 LEGEND: ¥ 0 ~ = 0 --, § Sandy, clay •top1011•, organics, mollt, brown. ~ Clay, eandy, very stiff, moist, brown, 5 "~27/12 ~~ 5 -3 tan. (CL) t3 Gravel, clayey, den .. , molat, tan. (GC) _J 10 [; .... tfW-1"2/12 10 p Drive sample. The symbol 27/12 Indicate• that 27 blow• of a 140 pound hamm•r falllng 30 Inch•• r. 'j-J 39/ 12 ~ +J2a/12 .. ~I we,.. ,..qulr.d to dme a 2,5 Inch 15 O.D. Callfomla aamplar 12 lnchH. S' HO TES: 20 ~ ~47/12 ~1 20 ..:Ji 1. Exploratory bor1ng1 we,.. drllltd on Augult 2, 2007 with 4-lnch dlamater, eond-ltem ouger and a traok-mauntad drlll rig. Exploratory boring• we,.. bockftued lmmtdlattly 25 ~A ~22/12 25 -I affar drilling op1raffona .,,.. completed. 2. Locations of exploratory borings shown on Rgu,.. 1 a,.. approximate. 30 ~23/12 30 ...:i 3. Ha free ground water was found In our exploratory boring• at the time of drllllng. ... Th111 exploratory boring• are 1ubject to th• explonatlona, 35 35 _. llmltatlona and conclualan1 aa contalnad In thl1 report. SUMMARY LOGS OF EXPLORATORY BORINGS Project No. GS050"8-120 J1i. 2 ... • II 5 3 2 0 -1 ·2 ·3 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING ~------------------------------------------------------------------~ 0.1 APPLIED PRESSURE -KSF Sample of CLAY, SANDY (CL) From TH-1 AT 4 FEET JOHN MILLER MILLER RESIDENCE PROJECT NO. GS05048-120 10 J:ILAB. TEMPLA T1!51To be Releaud\SWEU.-Wllh Prueurea2..sla 10 ORY UNIT WEIGHT= MOISTURE CONTENT:: 100 98 PCF 10.3 % Swell Consolidation Test Results FIG.3 .. J 3...-~~------------------------------------~--------------------- 1 EXPANSION UNDER CONSTANT _---+--11 _PRESSURE DUE TO WETIING ,_1JU I I I I I 111_"" ~1 _1 I l_L ___ --------·:-:---1 -1--:-- 2 z 0 a en z < Q. 1 x w ~ z ·2 a , Li . I -r-11 r"I en ti) w 0:: .3 Q. :::E 0 0 0 1 1 0 APPLIED PRESSURE • KSF sample of CLAY, SANDY (CL) From TH-1 AT 14 FEET I I I 10 ORY UNIT WEIGHT• MOISTURE CONTENT• 100 112 PCF 6.0 % ------------EXPANSION UNDER CONSTANT c::::: -PRESSURE DUE TO WETIING z 0 o.-__ _ en z < Q. >< -1 w z 0 ·2 Ui ti) w 0:: Q. -3 :::E 0 0 ~-----------------------------------------------------------------01 1 0 APPLIED PRESSURE -KSF Sample of CLAY, SANDY (CL) From TH-2 AT 14 FEET JOHN MILLER MILLER RESIDENCE PROJECT NO. GS05048-t20 J :\LAD. TEMPl..ATES\To be AolHMll\SWEl.L-Wllh P-.urn2.llla 10 ORY UNIT WEIGHT= MOISTURE CONTENT• 10 0 120 PCF 135 % Swell Consolidation Test Results FIG .4 { SLOPE PER REPORT ..............•.. ................. ................. ··············•·· ................. ................. .................. ................. ................. NOTE: DRAIN SHOULD BE AT LEAST 4 INCHES BELOW BOTTOM OF FOOTING AT 11-IE HIGHEST POINT AND SLOPE DOWNWARD TO A POSITIVE GRAVITY Oun.ET OR TO A SUMP WHERE WATER CAN BE REMOVED BY PUMPING. ml'ACllDN PER REPCIRI) ·:~·:·:::··-::·:.-:-::·:~ COVER GRAVEL wmf FlLlER FABRIC. ENCASE PIPE JN WASHED CONCRETE AGGREGATE (ASlM C3J, NO. 57 OR NO. 67). EXTEND GRAVEL TO TOP OF VOID. 4-INCH DIAMETER PERFORATED DRAJN PIPE. 11-IE PIPE SHOULD BE PLACED IN A lRENCH Wmt A SLOPE RANGING BETWEEN 1/8 INCH AND 1/4 INCH DROP PER FOOT OF DRAIN. Project No. GS05048-120 --nt~1 ~--BELOW GRADE WALL REINFORCING STEEL PER STRUCTURAL DRAWINGS PROVIDE POSITIVE SUP JOINT BElWEEN SL.AB AND WALL FLOOR SL.AB ._ __ DRIUED PIER PROVIDE PVC SHEETING GLUED TO FOUNDATION WALL TO REDUCE MOISTURE PENETRATION Exterior Foundation Wall Drain Fig. 5 •' SLOPE PER REPORT I " BACKFILL~ (COUPOSmON AND COMPACTION PER REPORTJ BELOW GRADE WALL COVER GRAVEL Wmt ALTER FABRIC ENCASE PIPE IN WASHED CONCRETE AGGREGATE (ASTM C33, NO. 57 OR NO. 67). EXTEND GRAVEL TO TOP OF VOID. PROVIDE PVC SHEETING GLUED TO FOUNDATION WALL TO REDUCE MOISTURE PENETRATION. Project No. GS05048-120 ................. ................ , ................. ................. ................. ....••........... ................. ................. ................. •..•............. ................. ................. ................. ................. ................. ................. NOTE: DRAIN SHOULD BE AT LEAST 4 INCHES BELOW 801TOM OF VOID AT THE HIGHEST POINT AND SLOPE DOWNWARD TO A POSmvE GRAVllY OUTLET OR TO A SUMP WHERE WAlER CAN BE REMOVED BV PUMPING. STRUCTURALLY SUPPORTED FLOOR SYSTEM CRAWL SPACE '"" OR \ VOID REINFORCING STEEL PER STRUCTURAL DRAWINGS VOID •----DRIUED PIER 4-INCH DIAMETER PERFORATED DRAIN PIPE. THE PIPE SHOULD BE PLACED IN A TRENCH WITH A SLOPE RANGING BETWEEN 1/8-INCH AND 1/4-INCH DROP PER FOOT OF DRAIN. Exterior Foundation Wall Drain Flg.6 MOISTURE DRY DEPTH CONTENT DENSITY LOT CFEET) (%) (PCF) TH-1 4 10.3 98 TH-1 14 6 .0 112 TH-2 9 7 .3 114 TH-2 14 13.5 120 TABLE I SUMMARY OF LABORATORY TESTING PROJECT NO. GS05048-120 A TIER BERG LIMITS SWELL TEST RESULTS" PASSING LIQUID PLASTICITY SWELL NO. 200 LIMIT INDEX SWELL PRESSURE SIEVE (%) (%) (%) CPSF) (%) 0 .5 0.4 16 3.3 SOLUBLE SULFATES (o/o) •SWELL MEASURED WITH 1000 PSF APPLIED PRESSURE, OR ESTIMATED IN-SITU OVERBURDEN PRESSURE. NEGATIVE VALUE INDICATES COMPRESSION. .... ~ DESCRIPTION CLAY, SANDY (CL) CLAY, SANDY lCL) GRAVEL, CLAYEY <GC) CLAY, SANDY <CL) Page 1 of 1