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HomeMy WebLinkAboutCT 00-06; BRESSI RANCH; AS-GRADED COMPLETION LETTER; 2004-02-09c1-oo-'x- Leighton and Associates, Inc. A LEIGHTON GROUP COMPANY February 9, 2004 Project No. 971009-009 To: Lennar Communities 1525 Faraday Avenue, Suite 300 Carlsbad, California 92008 Attention: Mr. Jim Urbina Subject: As-Graded Completion Letter, a Portion of Poinsettia Lane Between Station No. 68+70 and 93+65, Bressi Ranch, Carlsbad Tract No. 00-06, Carlsbad, California References: Leighton and Associates, 2001, Supplemental Geotechnical Investigation for Mass Grading, Bressi Ranch, Carlsbad, California, Project No. 971009-005, dated March 14, 2001 2003, Summary of Settlement Monitoring, Poinsettia Lane Between Station No. 68+72 and 73+50, Bressi Ranch, Carlsbad, California, Project No. 971009-009, dated November 20, 2003 Kimley-Horn, 2003, Grading and Erosion Control Plans for Poinsettia Lane at Bressi Ranch, Carlsbad, California, Drawing No. 397-2J, dated January 24, 2003 Introduction In accordance with the request of representatives of Lennar Communities, we have been performing geotechnical observation and testing services during the rough and fine grading of the Bressi Ranch project located in Carlsbad, California. This letter summarizes our geotechnical observation and testing services during the rough and fine grading operations for Poinsettia Lane (between Station No. 68+70 and 93+65) at the subject property. As of this date, the grading operations are essentially complete for the subject street. The rough and fine grading operations for the subject street were performed between June 2003 and January 2004. The grading operations were performed by Nelson and Belding while Leighton and Associates performed the geotechnical observation and testing services. Our field technicians were on site full-time during the grading operations while our field and project 3934 Murphy Canyon Road, Suite B205 • San Diego, CA 92123-4425 858.292.8030 • Fax 858.292.0771 • www.leightongeo.com 971009-009 geologists were on site on a periodic basis. Grading of the subject street included: 1) the removal of potentially compressible existing fill soils, topsoil, alluvium, colluvium, landslide deposits and weathered formational material; 2) the partial removal of saturated alluvium, installation of wick drains, and the placement of a surcharge fill along Poinsettia Lane Station No. 68+70 to approximately 73+50; 3) preparation of areas to receive fill; 4) excavation of formational material; and 5) the placement of compacted fill soils. Conclusions and Recommendations The rough and fine grading operations for a portion of Poinsettia Lane between Station No. 68+70 and 93+65 were performed in general accordance with the project geotechnical reports, geotechnical recommendations made during the rough and fine grading, and the City of Carlsbad requirements. It is our professional opinion that the subject street is suitable for its intended use provided the recommendations included in the project geotechnical report and the City of Carlsbad requirements are incorporated into the design and construction of the streets and associated improvements. The following is a summary of our conclusions: Geotechnical and geologic conditions encountered during the rough and fine grading were generally as anticipated. A comprehensive summary of the geotechnical and geologic conditions (including field density and laboratory testing, geologic units, geologic structure and faulting) will be summarized in the final as-graded report for the project. . Site preparation and removals were geotechnically observed. Fill soils were derived from onsite soils. Field density testing indicated that the fill soils were placed and compacted to at least 90 percent relative compaction (based on American Standard of Testing and Materials [ASTM] Test Method D1557) and near-optimum moisture content in accordance with the project recommendations. It is our professional opinion that the primary settlement of the fill soils is essentially complete including the area where the wick drains were placed (Leighton, 2003). Limitations The presence of our field representatives at the site was intended to provide the owner with professional advice, opinions, and recommendations based on observations of the contractor's work. Although the observations did not reveal obvious deficiencies or deviations from project specifications, we do not guarantee the contractor's work, nor do our services relieve the contractor or his subcontractor's work, nor do our services relieve the contractor or his subcontractors of their responsibility if defects are subsequently discovered in their work. Our responsibilities did not include any supervision or direction of the actual work procedures of the contractor, his personnel, or subcontractors. The conclusions in this report are based on test results and observations of the grading and earthwork procedures used and represent our engineering opinion as to the compliance -2 4 - Leighton 971009-009 of the results with the project specifications. If you have any questions regarding this letter, please contact this office. We appreciate this opportunity to be of service. Respectfully submitted, LEIGHTON AND ASSOCIATES, INC. edaJII K. Wagne , CEG 1612 Director of Geology Distribution: (2) Addressee (2) Lennar Comminutes, Attention: Mr. Michael Ugar (4) JT Kruer, Attention: Mr. Steve Lobaugh -3- Leighton