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Home My WebLink AboutCDP 10-12; SMERUD RESIDENCE; INTERIM REPORT OF GRADING; 2011-08-31CHRISTIAN WHEELER ENG1NEEP1NG August 31, 2011 Richard Smenud CWE 2100122.05 do Martin Volk - 568 Compass Road Oceanside, California 92054 Subject: . Interim Report of Grading Observations and Testing Results, Proposed Buena Vista Way. Residence, 1099 Buena Vista Way, Carlsbad, California. References: Report of Geotechnical Investigation, Proposed Buena Vista Way Residence, 1099 Buena Vista Way, Carlsbad, California, prepared by Christian Wheeler Engineering, dated May 28, 2010 (CWE 2100122.01). Ladies/ Gentlemen, In accordance with your request, our proposal and agreement dated May 3, 2010, and the requirements of Section 1704.7 of the California Building Code, Christian Wheeler Engineering has prepared this report to summarize our observations of the grading operations at the subject site and to present the results of our field and laboratory testing. The results of our field testing include in-place density tests performed in the fills placed during the grading operations for the subject property. The observation and testing services addressed by this report were coordinated by BTS Equipment and Strongside Builders. Our services were provided during the period between June 20, 2011 and July 28, 2011. INTRODUCTION AND PROJECT DESCRIPTION SITE DESCRIPTION: The subject site is a nearly rectangular shaped parcel of land located at 1099 Buena Vista Way, in the city of Carlsbad. The site is bounded on the south by Buena Vista Way, and is otherwise surrounded by single family residential properties. The property is vacant at this time, but appears to once have supported a single-family home and associated improvements. The relatively fiat lot is about 67 feet wide and 150 feet deep. Topographically, the site slopes gently to the northeast, with elevations ranging from 3980 Home Avenue i San Diego, CA 92105 e 619-550-1700 w FAX 619-550-1701 CWE2100122.05 August 31, 2011 Page about 741/2 feet mean sea level (MSL) at the southwestern corner to elevation 70 feet MSL at the northeastern corner. NEW CONSTRUCTION: The project consists of the construction of a single-family residential structure, and an attached accessory dwelling unit. The residence will be a two-story, wood-frame structure with an on- grade concrete floor slab; the accessory building will be a single-story structure with an on-grade concrete floor slab. Both structures are to be supported by conventional shallow foundations. A retaining wall, less than four feet in height, is to be located along the eastern property line. PLAN REFERENCE: In order to assist in our understanding of the various elements of the project, our firm was provided with grading and structural plans, approved and dated June 9, 2011. Plate No. 1 of this report is a reproduction of the grading plan, modified to show the approximate locations of our field tests and the relevant limits of the earthwork operations performed. SCOPE OF SERVICE Services provided by Christian Wheeler Engineering during the course of the earthwork included the following elements. Observing the earthwork operations as requested. Providing field recommendations for elements of the earthwork not specifically addressed by the referenced geotechnical report. Recording the approximate elevations and limits of significant geotechnical elements. Performing in-place density tests in the fills placed during grading operations. Performing laboratory maximum density, optimum moisture content, and expansion index determinations on the soils encountered in the earthwork. Determining the relative compaction of the fills placed. Preparing this report, summarizing our observations and test results CONTRACTOR GRADING: The grading earthwork addressed by this report was performed by BTS Equipment of El Cajon, California. The primary equipment utilized by the contractor in the work consisted of the following: CWE2100122.05 August 31, 2011 Page 1i John Deere700jDozer 1 Caterpillar Skid Steer 1 - - Water Hose FIELD OBSERVATIONS GENERAL: As scheduled by Strongside Builders, our field representatives observed the site preparation and grading operations for the construction of the building pads which are to support the subject structures. SITE PREPARATION: Site preparation began with clearing and grubbing on-site vegetation in preparation for the grading operations. GRADING: Topsoil and loose soils were excavated down to a depth where competent formational soils were exposed. The removals extended approximately three feet in depth and extended approximately five feet laterally outside any settlement sensitive improvements. Fill materials placed in the pads to support the residence, dwelling, and associated improvements consisted of on-site silty sands and imported clayey sand. These materials were typically thoroughly mixed and placed in relatively thin, uniform lifts, moisture- conditioned as needed and compacted by means of a tracking in fills by means of a crawler dozer. As recommended in the referenced report, fill materials were compacted to at least 90 percent of the materials. maximum dry density. FIELD AND LABORATORY TESTING FIELD TESTS: Field tests to measure the in-situ density and moisture content of the fills placed were conducted in accordance with ASTM Test Designation D6938; "Standard Test Methods for Density of Soil and Soil-Aggregate in Place by Nuclear Methods." The locations of the field tests were selected by our technician in areas discerned to exhibit relative compaction that was generally representative of that attained in the fill. Field density tests for grading operations were generally performed at a maximum interval of two feet vertically. Elevations were estimated using simple hand instruments measured against existing monuments, surveyor or contractor staking, the existing grade and/or elevations provided on the construction plans. The results and approximate locations of the field tests are shown on the attached Plate No. 1. CWE2100122.05 August 31, 2011 Page 4 LABORATORY TESTS: The maximum dry density and optimum moisture content of the soils predominantly encountered in the earthwork were performed in our laboratory by ASTM Test Designation D1557, "Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort." The tests were conducted in accordance with the methodology prescribed for the grain-size distribution of the soils tested. Representative samples of the soils present within the foundation zone of the proposed structures were tested for their expansion potential in accordance with ASTM D4829, "Standard Test Method for Expansion Index of Soils." The results of our laboratory testing are presented on the attached Plate No. 2. CONCLUSIONS GENERAL: It is the opinion of Christian Wheeler Engineering that the earthwork addressd by this report has been performed in accordance with the referenced geotechnical report, the City of Carlsbad grading requirement and the California Building Code. This opinion is basçd upon our observations of the earthwork operations, the results of the density tests taken in the field, and the maximum density tests performed in our laboratory. It is our further opinion that the building pads are suitable to support the subject residential structures. AS-BUILT GEOLOGY: The geologic units encountered during the earthwork operations were generally consistent with those anticipated in our referenced report of geotechnical investigation. The earthwork operations addressed by this report have, in our opinion, satisfactorily mitigated the potentially adverse conditions described in the referenced report. REMAINING EARTHWORK: As of the date of this report, additional earthwork remains to be done on the subject site. The remaining earthwork includes the following: A 2:1 fill slope located at the southwestern area of the subject property requires additional fills and further compactive efforts; an approximately four foot high retaining wall is to be constructed and backfilled along the western property line; additional removals are recommended for the western driveway and additional fills are required to achieve designed grades at the eastern driveway. Additionally, subgrade preparations should be made prior to the placement of concrete for on-grade floor slabs and driveways. All foundation excavations should be observed by a representative of this office prior to the placement of forms or reinforcement in order to verify that the footings have the proper dimensions and that the soil conditions are as anticipated. Our firm should be contacted when these operations are performed so that we can verify their compliance with the applicable specifications. CWE2100122.05 August 3l,2011 Page LIMITATIONS The descriptions, conclusions and opinions presented in this report pertain only to the work performed on the subject site during the period between June 20, 2011 and July 28, 2011. As limited by the scope of the services that we agreed to perform, the conclusions and opinions presented herein are based upon our observations of the work and the results of our laboratory and field tests. Our services were performed in accordance with the currently accepted standard of practice in'the region in which the earthwork was performed, and in such a manner as to provide a reasonable measure of the compliance of the described work with applicable codes and specifications. With the submittal of this report, no warranty, express or implied, is given or intended with respect to the services performed by our firm, and our performance of those services should not be construed to relieve the grading contractor of his responsibility to perform his work to the standards required by the applicable building codes and project specifications. Christian Wheeler Engineering sincerely appreciates the opportunity to provide professional services on this project. If you should have any questions after reviewing this report, please do not hesitate to contact our firm. Respectfully submitted, CHRISTIAN WHEELER ENGINEERING Jesse Bearfield, Staff Engineer -~~ # at. Charles H. Christian, R.G.E. #00215 Curtis R. Burdett, C.E.G. #1090 CHC/CRB:jdb cc: (1) martyvollcgmai1.com 14. IED E25 No.1 lExp -30-11 ENGINEERING OPEC =S--p)— — Alr,.1 LE TUTTEST - t pa P Nj Dl. Li 0V. BUENA VISTA WAY RESIDENCE 1099 BUENA VISTA WAY, CARLSBAD. CALIFORNLA DATE: AUGUST2011 JOB NO.: 2100122.0 BY: CHC/IDB PLATE NO.: RICHARD SMERUI) RESIDENCE 1099 BUENA OLSEN WAY CARLSBAD. CA I BY: CLAN K. VAN PENN 204 LX?. 3/31/IS DIV ENONEYR DALE PRO&CT NO. DUNNING NO. 10-12 470-SN H CHRETIAN WHEELER ENGINEERING CWE LEGEND APPROXIMATE COMPACTION TEST LOCATION [] ELEVATION AT EXCAVATION BOTTOM OMITS OF GRADING 1595 B/S/A V94 /4Y S QRf ARTIFICIAL FILL UNDERLAIN BY APN 155-25;-01 FF5 71.5 s: , PAD 71.0 Qop OLD PARALIC DEPOSITS / - I I Iz vi 69.0 — s\ / jFFE74700 / 71.0 PORCH A 742 9 - lit QUNIT A FS FFE 747 PAD TAO - - Ik r{ FFE74.7Qj' PAD 74.11 7L0 UNIT B-.4 N- QL t_J U H t9S— I I Qop / j CA000E Al ( Q!f [J GF742 JF 74.2 Qv - ---- - - N 003342 0 15000' ,) I Blii--AA WAY Ex W."01 htUSS FF575.0 o 1. PAD 745 SCALE: 1" = 20 SITE PLAN AND GEOTECHNICAL MAP • } ;jr 194 I - / ( p P • SUMMARY OF TESTS Project: Buena Vista Way Residence MASS GRADING _ Relative Comnaction Tests ASTM D29-22--9-1-7 Test No. Date Location Elev. (feet) Soil Type Moisture (%) Dry Density (pcf) Max. Density % Rel. Comp. 1 6/21/2011 Southern Half of Residence 71.5 2 8.5 122.2 126.2 96.8 2 6/21/2011 Southern Half of Residence 71.5 2 11.0 120.7 126.2 95.6 3 6/21/2011 Southern Half of Residence 72.0 2 9.2 114.7 126.2 90.9 4 6/22/2011 Northern Half of Residence 72.0 2 12.6 121.2 126.2 96.0 5 6/22/2011 Northern Half of Residence .72.0 2 13.2 119.0 126.2 94.3 6 7/26/2011 Southern Half of Residence 72.5 5 11.0 115.0 126.2 91.1 7 7/26/2011 Southern Half of Residence 73.0 5 12.8 117.3 126.2 92.9 8 7/26/2011 Southern Half of Residence 74.0 3 7.2 121.7 130.3 93.4 9 7/27/2011 Northern Half of Residence (PG.) 74.0 3 6.9 120.2 130.3 92.2 10 7/27/2011 Northern Half of Residence (PG.) 74.0 3 10.0 115.0 130.3 88.3 11 7/27/2011 Southern Half of Residence (PG.) 74.0 3 7.2 119.8 130.3 91.9 12 7/27/2011 Southern Half of Residence (PG.) 74.0 3 5.6 116.5 130.3 89.4 13 7/28/2011 Retest #10 74.0 3 11.4 118.7 130.3 91.1 14 7/28/2011 Retest #12 74.0 3 8.0 124.7 130.3 95.7 15 7/28/2011 Garage Pad (PG.) 73.5 3 8.2 124.3 130.3 95.4 16 7/28/2011 Garage Pad (PG.) 73.5 3 9.9 124.8 130.3 95.8 MAXTMUM DRYDENSIT andOPTIMUMMOISTURE CONTENT ASTM :1557-91 1 Soil Type Description USCS Optimum Moisture Maximum Dry Class (%) Density (pcf) 2 Grayish-Brown, SILTY SAND SM 9.3 126.2 3 Grayish-Brown, SILTY SAND SM 10.3 130.3 Light Gray, CLAYEY SAND Sc-90 1262 Import: _Moody's_(Oceanside,_California) P\TANSTON JNrx ASTM D4829 1 Soil Type Description USCS Class RI Potential Expansion 4 Light Gray, CLAYEY SAND SC 31 Low 6 Grayish-Brown, SANDY CLAY SC 8 Very Low CWE 2100122.05 Plate 2