HomeMy WebLinkAboutCT 00-06; BRESSI RANCH; AS-GRADED COMPLETION LETTER FOR MANUFACTURED SLOPES ON EL FUERTE; 2004-03-30971009-011
receive fill; 2) the excavation of stability fill and fill slopes keys; 3) excavation of formational
material; 4) the placement of subdrains in the stability fill keys, and 5) the placement of compacted
Fill soils.
Conclusions and Recommendations
The rough and fine grading operations for the manufactured slopes of El Fuerte Street (between
Station No. 8+50 and 57+25) 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 manufactured slopes
are 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 manufactered slopes for El Fuerte Street 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.
Stability fills were constructed to improve the gross stability of the cut slopes exposing
fractured and blocky formational material and/or other adverse geologic conditions on the site.
The stability fill keys were excavated in accordance with the project geotechnical
recommendations.
Fill slopes located above natural ground were constructed with a fill slope key. All keys were
excavated to a minimum of 15 feet wide, at least 2 feet into competent material along the toe-
of-slope with the key bottom inclined at least 2 percent into-the-slope.
Subdrains were placed along the bottom of the stability keys and at approximately 30-foot
vertical intervals. The subdrains were either outletted to the slope face or outletted into storm
drain facilities (inlet box, catch basin, concrete drainage swale, etc.).
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 Dl 557) 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.
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Leighton
971009-011
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
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.
Randall K. WagnerCEGI
Director of Geology
Distribution: (2) Addressee
(2) Lennar Comminutes, Attention: Ms. Christine Zortman
(1) iT Kruer, Attention: Mr. Chuck Knight
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Leighton