HomeMy WebLinkAboutCT 12-05; LA COSTA RESIDENTIAL; PAVERS DESIGN RECOMMENDATIONS; 2014-07-15LGO
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Geotechnical, Inc.
July 15, 2014 Project No. 12043-01
Ms. April Tornillo
Taylor Morrison
8105 Irvine Center Drive, Suite 1450
Irvine, CA 92618
Subject: Payers Design Recommendations for the La Costa Residential Development, City of
Carlsbad, California
References: Brick Industry Association, 2003, Flexible Vehicular Brick Paving, A Heavy Duty
Applications Guide, published January 2003.
LGC Geotechnical, Inc., 2014, Geotechnical Recommendations for Street Sections, La Costa
Residential Development "Montecina", City of Carlsbad, California, Project No. 12043-01,
dated July 8, 2014.
Introduction
In accordance with your request, LGC Geotechnical, Inc. has prepared this report presenting the
recommended payers design sections for the proposed La Costa residential development, City of Carlsbad,
California.
Payers DesiRn
Design Traffic Indices (TI) determined by the project Civil Engineer of 5.0 and 6.0 have been used for the
proposed paver areas. R-Value testing performed by this office on finished grade soils indicates a design R-
Value of 13 (see attached).
Concrete payers should be a minimum of 3 and 1/8 inches (80 mm) thick, rated for vehicular traffic.
Manufacturer's specific recommendations regarding the payers (required bedding and jointing sand, etc.)
should be implemented during construction. It should be noted that payers are typically underlain by a thin
layer of bedding sand followed by compacted aggregate base.
Calculations for the design sections resulted in payers sections that are suitable from a
standpoint (Table 1).
Aggregate base must be compacted in thin lifts to a minimum of 95 percent relative compaction of
maximum density per ASTM D1557. Subgrade soils must be compacted a minimum of 90 percent relati
compaction (ASTM D1557).
TABLE 1
Calculated Payers Section for Proposed State Street Townhomes
Design Vehicular Payers
Traffic
Indices Sand Thickness* (in) I Crushed Aggregate Base I (CAB) Thickness ** (in)
5.0 1 t 2 14 inches
6.0 1 to 2 11 inches
* It should be noted that bedding sand layer thickness should be obtainedfrom the Flexible Vehicular Brick
Paving: A Heavy Duty Applications Guide (Brick Industry Association, 2003).
**Crushed Aggregate Base material shall meet minimum specification of crushed aggregate base (CAB)
per Section 200-2 Untreated Base Materials per latest edition of Greenbook.
Concrete bands around the perimeter of the payers are recommended. The concrete bands should be at least 6
inches thick, with two No. 4 rebar placed longitudinally at approximately mid-height. The concrete should be
underlain by a minimum of 4 inches of crushed aggregate base material.
The thicknesses above are minimum thicknesses. Increasing the thickness of any or all of the above layers
will reduce the likelihood of the pavement experiencing distress during its service life. The above
recommendations are based on the assumption that proper maintenance and irrigation of the areas adjacent to
the roadway will occur through the design life of the pavement. Failure to maintain a proper maintenance
and/or irrigation program may jeopardize the integrity of the pavement and payers.
Limitations
Our services were performed using the degree of care and skill ordinarily exercised, under similar
circumstances, by reputable soils engineers and geologists practicing in this or similar localities. No other
warranty, expressed or implied, is made as to the conclusions and professional advice included in this report.
It should be understood that LGC Geotechnical, Inc. has relied on the accuracy of documents, verbal
information, and other material and information provided by you and other associated parties in preparation
of this report. LGC Geotechnical, Inc. makes no warranties or guarantees as to the accuracy or completeness
of information obtained from or compiled by others.
Project No. 12043-01 Page 2 July 15, 2014
We appreciate this opportunity to be of service. Should you have any questions or concerns regarding this
letter, please do not hesitate to contact our office.
Sincerely,
LGC Geotechnical, Inc.
Tim Lawson, CEG 1821, GE 2626
Geotechnical Engineer/Geologist
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Attachment: R-Value Test Result
Distribution: (3) Addressee (includes 2 wet-signed copies)
Project No. 12043-01 Page 3 July 15, 2014