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HomeMy WebLinkAboutTract Map 3929 Lot 133 Grading Compaction . \\'l. :R-2SJ Lo~~~3 . WAC GEDTECHNICAL -INC. October 08, 200 I W.O. 00486 Mr. Karl Lowery 9550 Hermitage Ln Riverside. CA 92503 Attention: Mr. Karl Lowery Subject: Report of Grading Compaction Testing for Intended Residential Construction for the Property Located South of the Intersection of Via Cielito and Avenida Del Sol, Tract 3929, Lot 133, Temecula, County of Riverside, California A.P.N.921-130-007 Reference: SubsUiface Soils Engineering Feasibility Investigation for Proposed Residential Building Construction and Foundation Evaluation for the Property Located South of the Intersection of Via Cielito and Avenida Del Sol, Tract 3929, Lot 133, Temecula, County of Riverside, California A.P.N. 921-130-007; dated April 24, 2001, by WAC Geotechnical, Inc. (W.O. 00486) Gentlemen: This report presents the results of our grading observation and compaction testing conducted during the placement and compaction of the fill placed for the property located south of the intersection of Via Cielito and Avenida Del Sol, Temecula, County of Riverside, California. The property is programmed to host a split level residential building, with conventional spread footings and slab-on-grade construction. Grading and testing were performed in accordance with the recommendations provided by this office as described in above reference. The results of fill compaction tests performed are presented herein. The results of the laboratory determined Maximum Dry Density for the soil type used during grading are shown within tabulations of soil compaction tests. Approximate locations offill compaction testing are shown . on Plate 1. , Grading Observations and Compaction Testing: The opinions presented are based upon our fill compaction testing and observations of the I grading procedures used, and represent our opinion as to the contractor's compliance with the i project plans and specifications, and did not include any supervision or direction of the actual , work performed by the contractor, or his workmen at the site. P.O. DDZ 3S4 . 38210 NDrth Shore Dr. . Fawnskln. ell 92333 (8'17) 688-3337 . (90Sl 8'18.3337 . Faz (SOSl 8'18.3347 \ AP.N.921-130-007 . . Page 2 In general, following site clearance, surficial soils were over-excavated to expose competent natural subgrades on which to place new structural fill to support slab on grade residential construction and foundations. Removal depths reached, on average, 3.0 feet below original grade for the structural area, to a width 5.0 feet outside of the foundation footprint for the proposed structure. Upon exposing competent bearing soils, exposed surface was scarified, moisture conditioned to near optimum moisture and compacted to a minimum of90% of the laboratory Maximum DryDensity. During grading, line and grade for planned pad and slope areas were supplied by the project civil engineers. WAC Geotechnical, Inc. assumes no responsibility pertaining to the correctness of the building pad locations and/or of the finished grade elevations supplied. In general, mass grading and compaction testing of the fill placed within the limits of the approved grading were performed as described below: I. Vegetation, surface trash, uncertified fill and other miscellaneous debris were cleared off the areas to be graded and such were disposed of, outside the grading area, prior to actual grading. 2. Following site clearance, the planned areas were overexcavated to a depth of approximately three feet for the building pad areas and approximately 3.0 feet for the driveway area. The approved bottom was scarified and compacted to 90% relative compaction. Fill slopes were constructed with an equipment width keyway with the heel I -foot below toe. Fill materials were compacted to at least 90 percent of the applicable laboratory Maximum Dry Density as determined per ASTM D1557-91 test method. 3. Approved on site stockpiled soils were placed in thin lifts by using a Cat 950F rubber tire compactor and a D-5C tractor, moisture conditioned by water hose and compacted. Each layer was compacted to at least the specified density before the n.ext layer was added. Deeper fill sections were benched into competent native soil materials. 4. Placement of compacted fill continued to the approximate limits and grades as determined by the project surveyor and/or by the grading contractor. Conclusions and Recommendations Based upon the observation of the construction sequences used during grading, it is our opinion I that the compacted fill for building pad construction has been placed in accordance with the I requirements set forth in the preliminary soils report, recommendations from this office, current I UBC, the project plans specifications and the local governing agency. The compacted fill placed I for pad area is intended to support slab on grade and foundation construction for a residential . structure. General recommendations presented in the preliminary soils report, Reference, should . be considered applicable for the compacted fill placed. WAC Geotechnical, Inc. 2. A.P.N.921-130-007 . . Page 3 It is recommended that future earthwork, if any, requiring additional fill placement beyond the limits and above the current finished grades, should be performed under direct review of the project soils engineering consultant. Should additional structures for the subject site, beyond the .area of the structural pad for residential structure, be planned, it is recommended that additional subsurface soils engineering investigation be conducted followed by a report and ,recommendations specific to planned building(s). The soils are considered to be very high (138) on the Expansive Index (ASTM D4829) for the residential building pads. Foundations may be designed based upon the following values: Allowable Bearing: Lateral Bearing: Sliding Coefficient: l500Ibs./sq.ft. 252Ibs./sq.ft. per foot of depth to a maximum of 1500 Ibs./sq.ft. 0.28 The above values may be increased as allowed by Code to resist transient loads such as wind or seismic. Building code and structural design considerations may govern depth and reinforcement requirements and should be evaluated. 2. Other Design Recommendations . FOOTING DEPTH Exterior 12-inches below lowest adjacent grade (in approved compacted fill materials) for one story and 18-inches below adjacent grade (in approved compacted fill materials) for 2-story. Interior 12-18-inches below lowest adjacent grade (in approved compacted fill materials) for one and 2-story, respectively. · FOOTING Width Exterior . 12-15 inches minimum for one and 2-story, respectively. Interior 12- I 5 inches minimum for one and 2-story, respectively. . FOOTING REINFORCEMENT Exterior & Interior All continuous; six No.5 bars, three near the top, three near the bottom for exterior and four No.5 bars, two near the top and two near the bottom for the interior. Concrete Slabs Slab Thickness: 6-inches nominal, reinforced with NO.4 bars at I2-inches on center, each way or equivalent. Reinforcement should be installed at mid-height in the slab. · Under-Slab Treatment Livin~ Areas- 6-mil Visqueen; cover with at least 2 inches of sand. Subgrade soils should be presoaked to contain at least optimum moisture content immediately prior WAC Geotechnical, Inc. .3 A.P.N.921-130-007 . . Page 4 to placing Visqueen and to be verified by the soils engineering consultant. The sand cover should be moistened prior to placing concrete. Grade Beam - A grade beam reinforced continuously with the garage footings should be constructed across all garage entrances, tying together the ends of the garage footings. This grade beam should be embedded at the same depth as the adjacent perimeter footings Garage Slab - Optimum moisture content in subgrade soil verified by the soils engineering consultant. · Fireolace Footings Fireplace footings shall have a minimum embeddment depth of 12-inches measured from the lowest adjacent grade and should be an integral part of the building foundation system. Fireplace slabs shall be treated in the same manner as the living area slabs (same as that noted in following sections for slab-an-grade construction). Prior to pouring footings, soils should be presaturated for 24-hours and field approved by the project soils engineering consultant or his representative. Resistance to lateral loads can be restrained by friction acting at the base of foundations and by passive earth pressure. A coefficient of friction of 0.28 may be assumed with the normal dead load forces for footing established on compacted fill. An allowable passive lateral earth resistance of 252 pounds per square foot per foot of depth, may be assumed for the sides of foundations poured against compacted fill. However, the maximum lateral passive earth pressure is recommended not to exceed 1500 pounds. For design, lateral earth pressures ofIocal soils when used as level backfill may be estimated from the following equivalent fluid density: Active: Passive: At Rest: 42 pcf 252 pcf 63 pcf It is recommended that all load bearing footings should be located only within the areas of the compacted fill placed for the building footprint. Footing excavations should be approved by WAC Geotechnical, Inc., and by the local government agency having jurisdiction, to ensure that suitable soils have been penetrated and that excavations are free of loose or disturbed soils. To prevent future cracking of concrete slabs-on-grade, it is recommended that no dumping of , loose and/or excess soils derived from footing and utility trench excavations be allowed on the I individual subgrades prepared to receive concrete slabs-on-grade. WAC Geotechnical, Inc. will I assume no responsibility in the event concrete is poured without proper field review of , slab-subgrades and foundation excavations. WAC Geotechnical, Inc. L\ AP.N.921-130-007 . . Page 5 To prevent foundation distress due to water drainage, use of planters adjacent to footings should be avoided. WAC Geotechnical, Inc. assumes no responsibility in event foundations are 'distressed during lifetime use of the property due to foundation soil saturation from planters. If ,planting of landscaping around structural footing areas cannot be avoided, a concrete planter box should be constructed with drainage collection points which allows for removal of water away ,from footings. A landscape architect should be contacted for design. Design of planter boxes adjacent to footings should be forwarded to this office for review and comment. Care should be taken to assure that drainage is directed away from structural foundation areas. Retaining structures should be designed using the following equivalent fluid density: Slope Surface of Equivalent Fluid Density (pet) Retained Material Imported Local (harz. to vert.) Clean Sand Site Soil Level 30 42 2:1 35 63 Backdrains will be required behind all retaining walls. Only free-draining granular materials (sand or gravel) are to used as retaining wall backfill to within 18-inches of surface grade. Utility trench backfill within the structural pad and beyond, should be placed in accordance with the following recommendations: o Exterior trenches along a foundation or a toe of a slope and extending below a I: I imaginary line projected from the outside bottom edge of the footing or toe of the slope, should be compacted to a minimum 90 percent. o All excavated trenches should conform to the requirements and safety as specified by the CalOSHA WAC Geotechnical, Inc. ...... :> AP.N.921-130-007 . . Page 6 , Closure ,Compacted fill placed is in accordance with the prevailing state-of the-art in the field of soil mechanics and foundation engineering and as recommended in by this firm. Fill materials placed lare intended to support concrete slab-on-grade, load bearing foundations for residential construction. Soils used during grading are considered to be silty/clayey, fine to coarse-grained sand/clayey sand. The fill material for building support is considered to be very high for 'expansive potential. To minimize potential differential settlement to footings, it is suggested that following excavations, excavated trenches shall be verified to ensure presence of only compacted fill :underneath foundation bottoms. As recommended herein, considering site soils, use of planters adjacent to footings shall be restricted to minimize potential foundation settlement due to water drainage. Should planters be placed in proximity to footings, planters should be within a sealed box area equipped with drainage system to direct excess water away from footing area. To prevent moisture migration to moisture sensitive areas, it is recommended that a vapor barrier, in the form of Vis queen or other commercially available similar products, should be used ,with proper protective coverings (sand, no gravel or rock) prior to concrete pour. The recommendations and opinions provided herein are based upon our observation of grading conducted during fill placement. We offer no other warranty other than striving to perform in a manner as generally used during site preparation and grading for similar grading projects within the County of San Bernardino. Thank you for the opportunity to be of service on this project. Should you have any questions regarding this report, please call the undersigned at your convenience. ~ Stan Schupp RCE 14568 Exp. 03/31/05 00486Compaclionf.lwplS4A WAC Geotechnical, Inc. '" ;, '.. . . '. Table I Compaction Testinl! Field Density Test Results (ASTM: D 2922-96) Test No. Test Depth Dry Density Moisture Content Soil Relative (Elevation below (pcf) (%) Max. Compaction (%) finish grade, feet) Dry Density (pcf) Test Date 8/2/01 1 4 119.8 11.1 123.0 97.4 2 2 115.5 10.7 123.0 93.9 3 3 113.8 11.6 123.0 92.5 4 2 112.5 10.1 123.0 91.5 5 0 116.2 9.8 123.0 94.5 Test Date 8/3/01 6 10 111.7 11.1 123.0 90.8 7 8 112.4 11.5 123.0 91.4 8 6 110.9 11.2 123.0 90.2 9 4 114.3 10.8 123.0 92.9 Test Date 8/6/01 10 2 112.9 10.6 123.0 91.8 II 0 115.3 11.3 123.0 93.7 12 0 117.2 10.9 123.0 95.3 13 7 118.7 11.1 123.0 96.5 Test Date 8/7/01 14 5 112.3 11.8 123.0 91.3 15 3 114.6 12.5 123.0 93.2 16 I 110.7 13.4 123.0 90.0 17 0 113.6 13.1 123.0 92.4 Test Date 8/10/01 18 2 116.4 11.3 123.0 94.6 19 0 114.5 10.9 123.0 93.1 20 3 111.4 12.1 123.0 90.6 21 0 115.3 10.3 123.0 93.7 22 0 111.5 9.9 123.0 90.6 23 2 115./ 9.3 123.0 93.6 24 0 113.3 9.2 123.0 92.1 25 0 114.2 8.8 123.0 92.8 26 0 117.3 8.3 123.0 95.4 27 0 111.9 9.6 123.0 90.9 Maximum Dry Density/Optimum Moisture Content Relationship (ASTM Dl557-91) 123.0 @ 9.4% WAC Geotechnical, Inc. 1 -. s . . 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