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HomeMy WebLinkAboutCT 01-04; CALAVERA HILLS VILLAGE U; GEOTECHNICAL UPDATE PHASE 10; 2005-04-25- 4 • : CIQ -U4 • S9 0 Geotechnical Geologic Environmental 5741 Palmer Way • Carlsbad California 92008 • (760) 438-3155 • FAX (760) 931-0915 '4 April 25, 2005 W.0. 4067-C-SC Brookfield Homes 12865 Pointe Del Mar, Suite 200 Del Mar, California 92014 Attention:.,,Ms Ten McHugh Subject: Geotechnical Update for Phase 10, Building Lots 42, 43, 44, 45, and 46, ViIIageU, Calavera Hills II, Carlsbad, San Diego County, California Dear. Ms McHugh In accordance with yä'ur request, GeoSoils, Inc. (GSI) has reviewed the referenced reports (see the Appendix) with 'respectto as-graded site conditions and has prepared this revised update report Grading and processing of original ground within the subject building pads was observed and selectively tested by a representative of GSI during the earthwork phase of development for the subject property, including a recent phase" of grading Which' resulted in additional cut excavation across the building pads 'and proof rolling (compaction) of the exposed subgrade to a minimum 90 percent relative compaction. - Based on our dbservations and testing, the area is generally considered suitable for its " intended residentiàl'use. Geotechnical observations and testing, performed during the initial phàsé of site gràding, and completed by this office, aresummarized in GSI (2004b). ". Based on our observations (including the most recent phase of cut excavation), the - findings, conclusions, and recommendations presented in our referenced reports (see the Appendix), including GSI (2003 and 2004b), are generally suitable with respect to the construction and development of.,the subject building pads.' Conditioning and/or prewetting of slab and foundation areas is recommended asindicated in GSI (2003, 2004a, and 2004b) Unless specifically superceded herein, the conclusions and recommendations contained in those reports (GSI,' 2003, "2004à and 2004b). are considered valid and applicable, and should be appropriately implemented SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING 4 - • - We recommend that observation and/or testing be performed by GSI at each of the following construction stages 4 '- - '- ' • i ' -• '. -. During grading/recertification. During excavation. During placement of subdrains, toe drains, or other subdrainage devices, prior to placing fill and/or backfill. After excavation of building footings, retaining wall footings, and free standing walls footings, prior to the placement of reinforcing steel or concrete. Prior to' pouring any slabs or flatwork, after presoaki ng/presatu ration of building pads and other flatwork subgrade, before the placement of concrete, reinforcing steel, capillary break (i.e., sand, pea-gravel, etc.), or vapor barriers (i.e., visqueen, etc.). During retaining wall subdrain installation, prior to backfill placement. During placement of backfill for area drain, interior plumbing, utility line trenches, and retaining wall backfill. During slope construction/repair. When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report. When any developer or homeowner improvements, such as flatwork, spas, pools, walls, etc., are constructed, prior to construction. A report of geotechnical observation and testing shall be provided at the conclusion of each of the above stages, in order to provide concise and clear documentation of site work, and/or to comply with code requirements.. GSI shall review project sales documents to homeowners/homeowners associations for geotechnical aspects, including irrigation practices, the conditions outlined above, etc., prior to any sales. At that stage, GSl will provide homeowners maintenance guidelines which shall be incorporated into such documents. OTHER DESIGN PROFESSIONALS/CONSULTANTS The design civil engineer, structural engineer, post-tension designer, architect, landscape architect, wall designer, etc., shall review the recommendations provided herein, incorporate those recommendations into all their respective plans, and by explicit reference, make this report part of their project plans. This report presents minimum Brookfield Homes W.O. 4067-C-SC Village U, Phase 10, Calavera Hills April 25, 2005 File: e:\wp9\4000\4067c.guflo Page 2 GeoSoils, Inc. design criteria for the design of slabs, foundations and other elements possibly applicable to the project. These criteria shall not be considered as substitutes for actual designs by the structural engineer/designer. Please note that the recommendations contained herein are not intended to preclude the transmission of water or vapor through the slab or foundation. The structural engineer/foundation and/or slab designer shall provide recommendations to not allow water or vapor to enter into the structure so as to cause damage to another building component, or so as to limit the installation of the type of flooring materials typically used for the particular application. The structural engineer/designer shall analyze actual soil-structure interaction and consider, as needed, bearing, expansive soil influence, and strength, stiffness and deflections in the various slab, foundation, and other elements in order to develop appropriate, design-specific details. As conditions dictate, it is possible that other influences will also have to be considered. The structural engineer/designer shall consider all applicable codes and authoritative sources where needed. If analyses by the structural engineer/designer result in less critical details than are provided herein as minimums, the minimums presented herein shall be adopted. It is considered likely that some, more restrictive details will be required. If the structural engineer/designer has any questions or requires further assistance, they shall not hesitate to call or otherwise transmit their requests to GSI. In order to mitigate potential distress, the foundation and/or improvement's designer shall confirm to GSI and the governing agency, in writing, that the proposed foundations and/or improvements can tolerate the amount of differential settlement and/or expansion characteristics and other design criteria specified herein. PLAN REVIEW Final project plans (grading, precise grading, foundation, retaining wall, landscaping, etc.), shall be reviewed by this office prior to construction, so that construction .is in accordance with the conclusions and recommendations of this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted. Brookfield Homes W.O. 4067-C-SC Village U, Phase 10, Calavera Hills April 25, 2005 File: e:\wp9\4000\4067c.guflO Page 3 GeoSoils, Inc. LIMITATIONS The materials encountered on the project site and utilized for our analysis are believed representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors. Inasmuch as our study is based upon our review and engineering analyses and laboratory data, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty, either express or implied, is given. Standards of practice are subject to change with time. GSI assumes no responsibility or liability for work or testing performed by others, or their inaction; or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properly implemented. Use of this report constitutes an agreement and consent by the user to all the limitations outlined above, notwithstanding any other agreements that may be in place. In addition, this report may be subject to review by the controlling authorities. Thus, this report brings to completion our scope of services for this portion of the project. Brookfield Homes WO. 4067-C-SC Village U, Phase 10, Calavera Hills April 25, 2005 File:e:\wp9\4000\4067c.guf10 Page 4 GeoSoils, Inc. S . S The opportunity to be of service is greatly appreciated. If you have any questions, please do not hesitate to call our office. Respectfully submitted, GeoSóils, Inc. Robert G. Crisman Engineering Geologist, CEG 1934 /Andrew T. II . Principal Engineer, No. GE2320 Exp. 12-31-05 RGC/ATG/JPF/jk Attachment: Appendix - References Distribution: (2) Addressee Brookfield Homes W.O. 4067-C-SC Village U, Phase 10, Calavera Hills April 25, 2005 File: e:\wp9\4000\4067c.guflO Page 5 GeoSoils, Inc. APPENDIX REFERENCES GeoSoils, Inc., 2004a, Response to plan check comments, Village U of Calavera Hills II, City of Carlsbad, San Diego County, California, W.O. 4067-C-SC, dated October 7. 2004b, Report of rough grading, Calavera Hills, Village U, Building lots 29 through 54, and Active Recreation Area, Carlsbad Tract 01-04, Drawing 407-6A, Carlsbad, San Diego County, California, W.O. 3459-B1-SC, dated September 15. 2003, Geotechnical update and grading plan review, Calavera Hills, Village U, Carlsbad Tract 01-02, City of Carlsbad, San Diego County, California, dated September 29. Hunsaker and Associates, San Diego, Inc., 2003, Grading plans for Calavera Hills Village U, Carlsbad Tract 01-03, Drawing No. 407-06, J.N. 0227, dated December 16. International Conference of Building Officials 2001, California building code, California Code of Regulations, Title 24, Part 2, Volume 2, California Building Standards Commission, Adopted November 1, 2002. ____ 1997, Uniform building code.