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HomeMy WebLinkAboutCT 00-02; CALAVERA HILLS 2; THIRD REVISION OF PAVEMENT DESIGN REPORT; 2004-05-14Geotechnical Coastal Geologic Environmental 5741 Palmer Way • Carlsbad, California 92010 (760) 438-3155 FAX (760) 931-0915 May 14, 2004 W.O. 4030-E-SC Calavera Hills II, LLC 2727 Hoover Avenue National City, California 91950 Attention: Mr. Don Mitchell Subject: Third Revision of Pavement Design Report, Calavera Hills II, Cannon Road Stations 125 to 164, City of Carlsbad, San Diego County, California Dear Mr. Mitchell: In accordance with your request, GeoSoils, Inc. (GSl), has prepared this revised preliminary design and construction recommendations for asphalt concrete (AC) pavement at the subject site. The scope of services provided in preparation of this report included a review of GSI (2003), and providing a revised pavement design for that portion of Cannon Road where the representative resistance R-value of the pavement subgrade is less than 12. PAVEMENT DESIGN Pavement section design was performed in accordance with the California Department of Transportation (Caltrans) Highway Design Manual of Instructions and the City of Carlsbad Standard Drawings (see the Appendix). Pavement sections presented are based on the aforementioned criteria and resistance value (R-value) data (see the attached Figures 1 through 4), determined from soils exposed at, or near, final subgrade elevations within the subject areas. R-value testing was performed in accordance with the latest revisions to the Department of Transportation, State of California, Material & Research Test Method No. 301. Pavement design was aided with the computer software programs PAVE and NEWCON90. ASPHALT CONCRETE PAVEMENT Structural Section R-values ranging from 5 to 28 were determined for subgrade soils onsite and used in pavement design. The recommended pavement sections are presented in the following table: AGREGA BASE TBAFIC SUBGRADIE THICKNESS THICKNESS'' TRAFFIC AREA iNX R V;AL1 JE lnches) (inces) Cannon.Roäd 8.5 28 5.0 13.0 Stations i25+22 to 130 +50 Cannon Road .. 8.5 27 :5;Q 13.0 Stations 1.30.to 135+2 Cannon Road . 8.5 6 6.0* . 20.0* .Stations 135+22 to 140 . . Cannon Road . . 8.5 5 6.0k 20.0* Stations 140+22 to 145 +_iO . Cannon Road 8.5 6 6.0* .20.0* Stations 14514 to .1 50 9 Cannon Road. 8.5 .6 6.0* . 20.0k Stations 150,to 164+50 . . . . .. ' City minimum (2) Denotes Class 2 Aggregate Base R >78, SE >25) . . . * Càltrans requirements . . . S. •• . All pavement installation, including preparation and compaction of subgrade, compaction of base material, and placement and rolling of asphaltic concrete shall be done in accordance with the City guidelines and under the observation and testing of the project geotechnical engineer and/or the City. . . . The recommended pavement sections are meant as, minimums. If -thinner or highly variable pavement sections are constructed increased maintenance and repair may be needed Positive site drinage shall be maintained at all times Water shall not be allowed to pond or seep into the ground. If planters ori,andscaping are adjacent to paved areas, measures shall be taken to minimize the potential for water to enter the pavement section If the ADT (average daily traffic) orADTT (average dailytrucktraffic) increases beyond that intended, as reflected by the traffic- index (s) used for design, increased. maintenance and repair could be required for the pavement section. PAVEMENT GRADING RECOMMENDATIONS General. All section changes shall be properly transitioned If adverse conditions are encountered during the preparation of subgrade materials, special construction methods may need to S be.employed. A GSI representative shall be present .for the preparation-of subgrade, base rock, and asphalt concrete. . . • : . • . . S .:Caiavera Hills ..119 LLC . .S . S • . . . W.O. 4030E-SC Cannon Road, Calavera Hills II . . . S May 14; 2004 FiIe:e:\wp9\3900\4030e.rpdr3 . . . . . .. . . . Page 2 Ge'05089z, Inc. Subgrade Within street and parking areas, all surficial deposits of loose soil material shall be removed and recompacted as recommended. After the loose soils are removed, the bottom is to be scarified to a depth of at least 12 inches, moisture conditioned as necessary, and compacted to 95 percent of the maximum laboratory density, as determined byASTM Test Designation D-1 557. Deleterious material, excessively wet or dry pockets, concentrated zones of oversized rock fragments, and any other unsuitable materials encountered during grading shall be - removed. The compacted fill material shall then be brought to the elevation of the proposed subgrade for the pavement. The subgrade shall be proof-rolled in order to ensure a uniform firm and unyielding surface. All grading and fill placement shall be observed by the project sail engineer and/or his representative. Base Rock Compaction tests are required for the recommended base section. Minimum relative compaction required will be 95 percent of the laboratory maximum density as determined by ASTM Test Designation D-1557. Base aggregate shall be in accordance with the "Standard Specifications for Public Works Construction" (green book), 1997 edition, or standard Caltrans Class 2 base rock (minimum R-value = 78). Paving Prime coat may be omitted if all of the following conditions are met: The asphalt pavement layer is placed within two weeks of completion of base and/or subbase course. Traffic is not routed over completed base before paving. Construction is completed during the dry season of May through October. The base is kept free of debris prior to placement of asphaltic concrete. If construction is performed during the wet season of November through April, prime coat may be omitted if no rain occurs between completion of base course and paving and the time between completion of base and paving is reduced to three days, provided the base is free of loose soil or debris. Where prime coat has been omitted and rain occurs, traffic is routed over base course, or paving is delayed, measures shall be taken to restore base course and subgrade to conditions that will meet specifications as directed by the soil engineer. Calavera Hills II, LLC Cannon Road, Calavera Hills II Fi1e:e:\wp9\3900\4030e.rpdr3 Geosoffs, Inc. W.O. 4030-E-SC May 14, 2004 Page 3 Drainage Positive drainage shall be provided for all surface water to drain toward the curb and gutter, or to an approved drainage channel. Positive site drainage shall be maintained at all times. Water shall not be allowed to pond or seep into the ground. If planters or landscaping are adjacent to paved areas, measures shall be taken to minimize the potential for water to enter the pavement section, such as cut-off walls. etc. OTHER DESIGN PROFESSIONALS/CONSULTANTS The design civil engineer shall review the recommendations provided herein, incorporate those recommendations into their plans, and by explicit reference, make this report part of their project plans. 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 mayvary 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 is expressed or implied. 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. . . . Calavera Hills II, LLC Cannon Road, Calavera Hills II File: e:\wp9\3900\4030e.rpdr3 W.O. 4030-E-SC May 14, 2004 Page 4 The opportunity to be of service is greatly appreciated. If you have any questions, please do not hesitate to call our office. Respectfully su ED Q GeoSoils, Inc. N. 1934 ( Ex. 03o1 Robert C. Crisman\ Engineering Geologist, RGC/JPF/DWS/jk Attachments: Appendix - References Distribution: (1) Addressee (2) Jobsite, Attention: Mr. Torn LaMarca (2) City of Carlsbad, Attention: Mr. Joe McMahon (1 wet signed) Calavera Hills II, LLC W.O. 4030-E-SC Cannon Road, Calavera Hills If May 14, 2004 FiIe:e:\wp9\3900\4030e.rpdr3 Page 5 GUs, Inc. V •- Reviev /4d Civil Ei APPENDIX REFERENCES American Public Works Association, 2000, "Greenbook" standard specification for public works construction. California Department of Transportation, 1995, Caltrans, Standard specifications, July printing. Carlsbad, City of, 1993, Standards for design and construction of public works improvements in the City of Carlsbad. GeoSoils, Inc., 2003, Pavement design report, Calavera Hills II, Cannon Road Stations 125 to 164, City of Carlsbad, San Diego County, California, W.O. 4030-E.-SC, dated December 23. NEWCON90, 1991 Computer program for the determination of asphalt pavement sections, version: April 30. PAVE, Computer program for the determination of asphalt concrete pavement sections. State of California, Department of Transportation, 1987, Highway design manual of instructions, fourth edition.