The URL can be used to link to this page

Home My WebLink AboutCDP 06-16; MATSUBARA RESIDENCE; RESULTS OF COMPACTION TESTING AND INSPECTION; 2007-04-09I (T'\ 1141 E,,i,wcrmq, i,,c CIVIL GEOTECHNICAL & QUALITY ENGINEERING I FOUNDATION DESIGN * LAND SURVEYING * SOIL TESTING CLIENT MATSUBARA I PROJECT MAT 608-CDG DATE 9 APRIL 2007 1 MR. EARNEST MATSUBARA 3560 Windsor Road Oceanside, CA 92056 Subject Results of Compaction Testing and Inspection for the Residence located 1 on Chinquapin Ave., Carlsbad, CA (APN 206-262-11) Reference(a) Our Limited Soil Investigation Report dated 9 April 2007 I Gentlemen Pursuant to your request, we have completed our inspection and compaction I testing of the re-grading operations for the subject parcel Locations of our field density tests are shown on Enclosure (1), and the results of these tests are detailed 1 on Enclosure (2) Site preparation, soil compaction and testing were accomplished between 4 I and 10 June 2008 Based on our observations and testing, it is our opinion that the work performed during that period was in general conformance with the I requirements of Reference (a), the Approved Grading Plan and the City of Carlsbad Grading Ordinance. SITE GRADING On 4 June, clearing began on the subject lot with the contractor removing some surface vegetation. All debris was removed from the pad grading- radin area. On this date, the contractor over-excavated the surface soils for the house pad by removing the surface materials to an approximate depth of 3 to 5 feet below the existing surface, where firm natural ground was encountered. The contractor started on the southerly 1/2 of the pad then continued grading from south to north The bottom of each excavation was scarified, watered, and recompacted prior to replacing the native stockpiled soils The limits of over-excavation extended a minimum of 5 feet outside of the proposed building foundations The over- excavation grading operation was accomplished to help mitigate the effects of differential settlement of the proposed structure' The contractor placed and compacted the native soils on the house pad until the designed pad grades were achieved 1611 A SO MELROSE DRIVE #285 VISTA, CA 92081 547i .(7 3 a qx:A, q1 II&II Enqi:werinq, I:w Mat 608cdg Density was achieved by the use of a rubber tire loader compacting the soil. 1 as fill was placed in thin lifts. Since the existing soil was low, in moisture content, the contractor spent additional time and effort in his mixing operation in order to I ensure near optimum moisture and-proper compaction in the fill material. I . As indicated by our Compaction Test Results, Enclosure (2), density tests performed in the construction of the house pad indicated over 90% relative compaction as compared to the Maximum Dry Density per ASTM Test Procedure I D155701. I SOIL EXPANSION The native materials exposed at surface grades for, the subject pad are considered to have a non-expansion potential (El = 0) according to Reference (a). I Therefore, no additional foundation or slab requirements are considered necessary in regard to soil expansion It is anticipated that the building footings may I experience less.than 1 inch settlement with less than V2 inch differential settlements between adjacent footings of similar sizes and loads. I SEISMIC DESIGN For seismic design purposes, the "Site Class D" can be used for the soils I , underlying the subject site, and the procedures outlined In the 2007 California Building Code, CBC, '(Sections 1603-A and 1613-A - EARTHQUAKE LOADS) should be used for calculations of the seismic coefficients for structural design The civil/structural engineer should consult with the project geotechnical j consultant if additional geotechnical information is needed for the seismic design. No active faults are known to exist within or near the site. The Rose I Canyon Earthquake Fault (Type B) is located approximately more than 10 kilometers from the site. The property is not located within an area designated as I , a special studies/earthquake zone under the Aiquist-Priolo Earthquake Zone/Special' Studies Act. , RETAINING WALLS An equivalent fluid pressure of 35 pcf may be used for design of retaining walls with level backfill and 55 pcf for 2H:1V sloping backfill. These figures are based on a drained condition and use of granular backfill having a sand equivalent 2 1611-A SO. MELROSE DRIVE #285, VISTA, CA 92081-5471 Ph: (760) 945-3150 Fax: (760) 945-4221 II&II Enqincerinq, Inc. Mat 608-cdg of 30 or greater. If the native soils are used as backfill, the equivalent fluid pressure of 35 pcf (level) and 55 pcf(2H:1V slope) for active conditions and 60 pcf (level) and 75 pcf (211: 1V sloping) for at-rest conditions can be used BUILDING FOUNDATIONS Building Foundations shall be sized and constructed in accOrdance witli the recommendations found in the latter part of this Report. For foundation design purposes, an allowable bearing strength of 1850 psf maybe assumed for all continuous or spread footings founded in dense native soils compacted to 90% relative compaction per ASTM D 155701. .It is recommended that the continuous perimeter foundations and concrete slabs for a light-weight, wood framed structure shall be reinforced in accordance with the following minimum designs: a. For slab-on-grade floors: -it, is recommended that the continuous perimeter foundations for a single story structure shall extend a minimum depth of 15 inches and a minimum width of 15 inches into the firm' native or compacted fill material as measured from the lowest adjacent grade. A minimum of 18 inches deep by 15 inches wide shall be used for a two story structure. b All foundations shall be reinforced with at least four No .4 steel bars, two bars shall be placed 3 inches from the top of the foundation and the other bars shall be placed 3 inches from the bottom. As an4 alternative to the 4 steel bars, the contractor may substitute two No. 5 steel bars, one top and one bottom. c. Footings placed on or adjacent to the top of cut or fill slopes flatter than. 1H: 1 shall have a minimum horizontal distance of 10 feet from the bottom Edge of the footings to the face of the slope, for slopes less than 20 feet in height. For slopes greater than 20 feet, a horizontal distance of H13 shall be used where H= height of slope, but need not exceed 40 feet maximum (See Attachment A) I . A. All interior concrete slabs shall be a minimum of 4 inches in thickness and reinforced with a minimum of No 3 rebar at 18 inches on center both ways placed in the center. of the slab. The bars shall be bent downward into the I perimeter footings and wire tied to the foundation steel at 18 inches on center. In order to minimize vapor transmission, an impermeable membrane (ie: 10 mil I 3 I 1611 A SO MELROSE DRIVE #285 VISTA, CA 92081-547i Ph (760) 945-3150 Fax (760) 945-4221 Its áh,ceriisu. I,w. ' Màt6O-cdc. visqueen) shall be placed over 2 inches of clean, poorly graded, coarse sand, decomposed granite, or crushed rock The membrane shall be covered with 2 inches of sand to protect it during construction and the sand should be lightly, moistened just prior to placing concrete All concrete used on this project shall contain Type II cement with a maximum water/cement ratio of 0.50 and a minimum concrete strength of 2500 psi unless otherwise increased on the Building Plans. e. Interior concrete slabs shall be provided with saw-cut joints spaced at a maximum of 10 feet on center each way within 24 hours after the pour and the saw-cuts shall be 1/4 of the slab thickness It is imperative that the drainage system around the proposed structure shall be designed and implemented to provide positive drainage away from all buildins in order to preclude moisture intrusion into the subgrade soils beneath the building foundations and slabs f Exterior slabs for hardscape, pooi decks, walkways, patios, etc shall be a minimum of 4 inches in thickness and reinforced with a minimum of No 3 steel rebars at 18 inches on center each way The reinforcing steel shall be placed in the upper 1/3 of the slab and held in place with concrete chairs Other Recommendations for Reducing Slab Cracking While not a geotechrncal issue, the potential for slab cracking may also be reduced by careful control of water/cement ratio and slump of concrete The contractor should take appropriate curing precautions during the pouring of concrete in hot weather to reduce the cracking of slabs A slip sheet (or equivalent) can be utilized if grouted tile, marble tile, or other crack sensitive floor covering is planned directly on the concrete slabs These foundation recommendations are minimum design requirements for the soils encountered during grading, however, actual foundations shall be designed by the Structural Engineer for the expected live and dead loads, and for wind and seismic loads. Findings of this Report are valid as of this date, however, changes in conditions of a property can occur with passage of time, whether they be due to natural processor works of man on this or adjacent properties In addition, changes in applicable or appropriate standards occur whether they result from 4 1611 A SO MELROSE DRIVE #285 VISTA, CA 92081-5471 Ph (760) 945-3150 Fax (760) 9454221 it I I • , II&II Lii qinecriiiq, in I Mat6O8-cdg t 1 , 1egis1ati0n orbroadenin -of knowledge; Accordingly, findings of this Repoft may be invalidated wholly or partially by changes outside our control Therefore, this Report is subject to review and should not be relied upon after a period of one I year. This Report is issued with the understanding that it is the responsibility, of the owner or of his representative to ensure that the information and recommendations contained herein are called to the attention of the project I Architect and Engineer and are incorporated into the plans Further, the necessary steps shall be taken to ensure that thecontrãctor and subcontractors 'cárry out such I.: recommendations in the field. - - The Engineer has prepared this Report for the exclusive use of the client and I authorized agents This Report has been prepared in accordance with generally accepted soil and foundation engineering practices No other warranties, either I expressed or implied, are made as to the professional advice provided under the terms of this agreement, and included in the Report I , B & B Engineering Inc. and Assdciates appreciate this opportuhity to' be of• service Should you have any questions regarding this project, please do not I hesitate to contact us 4 Sinerely, Stephen B.Teter RCE 38623 Expires 3-3.1-09 I. 1611 -A SO. MELROSE DRIVE #285, VISTA, CA 92081-5471 Ph: (760) 945-3150 Fax (760) 945-4221 S ' -. /3 • APPROXIMATE LOCATION OF FIELD DENSITY TEST PLOT PLAN I Owner: MR. EARNEST MATSUBARA SITE CHINQUAPIN AVE. S I Address CARLSBAD, CA. I1&11 EISqiIifPIiIRI, 11w .P.N.: 206-262-11 • S Project: MAT 608-CDG - Date: June-08 . . S Enclosure (1) II&II Enqinccrinq, Inc Client MR. EARNEST MATSUBARA Proiect MAT 608 CDG Date: Jun-08 - Test No. Test Date Test Location Test El/Depth - Soil Type Dry Density, pcf Moisture,% Relative Retest Field I Maximum Field Opt. Compaction No. 1 6/5/08 GARAGE PAD O-X 105. A 120.3 128.0 92 9.0. 94 2 6/5/08 HOUSE PAD O-X 106 A 124.0 128.0 9.2 9.0 97 3 6/5/08 HOUSE PAD O-X 105 A 119.0 128.0 5.8 9.0 93 4 6/5/08 HOUSE PAD O-X 106 A 120.6 128.0 10.3.9.0 94 5 6/10/08 GARAGE PAD O-X 105 A 118.2 128.0 6.5 90 92 6 6/10/08 GARAGE PAD O-X 106 A 119.2 128.0 6.7 9.0 93 7 6/10/08 GARAGE PAD O-X 107 A 115.8 128.0 8.4 9.0 90 8 6/10/08 GARAGE PAD O-X 107 A 121.5 128.0 62 9.0 . 95 9 6/10/08 HOUSE PAD O-X 106 A 121.8 128.0 6.5 9.0 95 10 6/10/08 HOUSE PAD O-X 107 A 122.91 128.0 7.5 90 96 11 6/10/08 HOUSE PAD O-X 107 A 120.3 128.0 7.4 9.0 94 12 6/10/08 HOUSE PAD O-X 107 A 120.4 128.0 9.5 90 94 13 6/10/08 HOUSE PAD O-X 108 A 120.4 128.0 59 9 94 COMPACTION CURVE DATA SOIL TYPE AND DESCRIPTION OPTIMUM MOISTURE% MAXIMUM DRY DENSITY (pcf) A. BROWN SILTY SAND . 12.5 125.5 COMPACTION TEST DATA Enclosure (2)