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HomeMy WebLinkAboutCT 02-16; ROBERTSON RANCH; PAVEMENT DESIGN REPORT; 2008-10-10(Jç02.—Lca S9 0 Geotechnical • Geologic • Coastal • Environmental 5741 Palmer Way Carlsbad, California 92010 • (760) 438-3155 • FAX (760) 931-0915 October 10, 2008 W.O. 5353-El-SC Brookfield San Diego Builders, Inc. 12865 Pointe Del Mar, Suite 200 Del Mar, California 92014 Attention: Mr. Greg McDonnell Subject: Pavement Design Report, Glen Avenue, Station 26 to the Cul Du Sac, Robertson Ranch East Village, City of Carlsbad, San Diego County, California Dear Mr. Pevney: In accordance with your request, GeoSoils, Inc. (GSI) has prepared preliminary design and construction recommendations for asphalt concrete (AC) pavement at the subject site. The scope of services provided in preparation of this report include a review of the referenced reports and documents (see the Appendix), an evaluation of the pavement section for the subject area, and preparation of this report. PAVEMENT DESIGN Pavement section evaluation was based on traffic index (TI) values provided by (O'Day Consultants, personal communications). Pavement sections were evaluated 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 table), evaluated from soils exposed at, or near, final subgrade elevations within the subject areas. R-value testing was performed in general accordance with the latest revisions to the Department of Transportation, State of California, Material & Research Test Method No. 301. ASPHALT CONCRETE PAVEMENT Structural Section Traffic Indices (TI) were provided by the project civil engineer (O'Day Consultants, personal communication) as 5.0 for the subject traffic areas. .11-values (see Plates 1 through 3) ' ranging from 6 to 20 were obtained for representative subgrade soils onsite and used in pavement design. The recommended pavement sections are presented in the following table: . .' . APPROXIMATE : TRAFFIC :.::.: •. SUBGRADE :.:....(....A.;C:.....: THICKNESS : .MEGA, i BASE THICKNESS"" TRAFFIC AREA INDEX'1 R-VALUE (Inches) (inches) ., • , iGlen Avenue, Stations 26 5.0 9 4.0 8.0(2)* to 28+50 Glen Avenue, Stations 28+L0 5.0 6 4.0 8.5* to31'2 ' . -. [Glen Avenue, Stations31 5.0 1.20 Cul Du Sac 4.0 . . Per O'Day Consultants, (personal communication) . (2) Exceeds City minimum . )3) Dnotes Class 2 Aggregate Base R >78, SE >25) . - (4) GSI does not recommend using less than 6 inches of AB, although 5 inches was calculated * Exceeds Caltrans requiremehts . . -. All pavement instalIatiön, includin preparation and compactionof subgrade, oorripaction of base material, and placement and rolling of asphaltic concrete, shall be done in accordance with the City guidelin'e's, and under the observation and testing of the project geotechnicàl engineer and/or the City. ltshoIjld be noted that subgrade lime treatment was previously waived by the City for the construction of pavement in the ,Calaèra HiIIs/Robertsori•Ranáh area (GSI;-2007a, 2007b, 2007c, 2004a,2004b, and 2004c). It is therefore anticipated that lime stabilization ii!I nbt be pertorriied for the current road construction; It should also be noted that the pavementthections presented for low R-value subgrades exceed the 'minimum design thickness, using Caltrans design methodology, by an additional 1 inch of base, for these relatively onerous subgrade conditions It is recommended that irrigation water not be alloWed to enter these low R-value soils, or - distress., The recommended pavement sections are rrieaht as minimums. If thinner orhighIy variable pavement sections are constructed, increased maintenance 'and repair may be needed...The recommended pavement sections provided above are intended as a minimum guideline If thinner or highly variable pavement sections are constructed, increased maintenanbe and repair could be expected If the ADT (average daily traffic) or - Brookfield San Diego Builders,Inc. Glen Ave., Robertson Ranch East Village. File:e:\wp9\5300\5353e1 .pdr GeoSoils, Inc. W.05353-E1-SC October 10, 2008 Page ADTT (average daily truck traffic) increases beyond that intended, as reflected by the TI used for design, increased maintenance and repair could be required for the pavement section. Consideration should be given to the increased potential for distress from overuse of paved street areas by heavy equipment and/or construction related heavy traffic (e.g., concrete trucks, loaded supply trucks, etc.), particularly when the final section is not in place (i.e., topcoat). Best management construction practices should be followed at all times, especially during inclement weather. 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 be employed. A GSI representative shall be present for the preparation of subgrade, base rock, and asphalt concrete. 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 by ASTM test designation D 1557. 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 soil 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 Section 26 of Caltrans Standard specifications (California Department of Transportation, 2006), for Caltrans Class 2 aggregate base. Brookfield San Diego Builders, Inc. Glen Ave., Robertson Ranch East Village File: e:\wp9\5300\5353e1 .pdr GeoSoils, Inc. W.O. 5353-El-SC October 10, 2008 Page 3 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. 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 may vary due to seasonal changes or other factors. Brookfield San Diego Builders, Inc. W.O. 5353-El-SC Glen Ave., Robertson Ranch East Village . October 10, 2008 File: e:\wp9\5300\5353e 1.pdr Page 4 GeoSoils, Inc. - p 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 express 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. The opportunity to be,of service is greatly appreciated. If you have any questions, please do not hesitate to call our office. Respectfully submi GeoSoils, Inc. Robert G. Crism 0 :/'1 Engineering Geologi , 34 RGC/ATG/JPF/jk inarew i. uuatein Geotechnical Engineer, GE 2320 Attachments: Plates 1 through-3 - R-value Test Results. Appendix - References Distribution: (4) Addressee IU Brookfield San Diego Builders, Inc. Glen Ave., Robertson Ranch East Village File: e:\wp9\5300\5353e1 .pdr GeoSoils, Inc. W. 0. 5353-El -SC October 10, 2008 Page 5 TEST SPECIMEN A P r n Compactor air. pressure PSI 140 110 80 Water added % 3.4 5.1 6.8 Moisture at compaction % 17.0 19.0 21.0 Height of sample......... _IN------.2.5 2.52 2.53. Dry density PCF 111.5 107.1 103.3 RVaIue by exudation 13 9 7 R-Value by exudation, corrected 13 9 7 Exudation pressure PSI 496 323 161 Stability thickness FT 1.89 1.98 2.021 Expansion pressure thickness FT 0.70 0.37 0.001 DESIGN CALCULATION DATA Traffic index, assumed 8.5 Gravel equivalent factor, assumed 1.25 Expansion, stability equilibrium 0 R-Value by expansion NA R-Value by exudation 9 R-Value at equilibrium 9 Expansion, Stability Equilibrium 3.00 2.50 2.00 >, Cl) Cl) 1.50 a) 0 i-1.00 I- a) > 0050 c.ot I'' I I I I I I I I I I I I 0.00 0.50 1.00 1.50 2.00 2.50 3.00 Cover Thickness by Expansion Pressure (ft) SAMPLE INFORMATION Sample Location: RV-1, 26+30-28+50 Sample Description: Gray Sandy Clay Notes: 0% Retained on 3/4 inch sieve 0 GeoSoils, Inc. R - VALUE TEST RESULTS 5741 Palmer Way Project: BROOKFIELD Carlsbad CA 92008 Telephone: (760) 438-3155 Number: 5353-El-SC Fax: (760) 931-0915 Date: Oct-08 Plate: 1 TEST SPECIMEN A R C fl Compactor air pressure PSI 280 80 80 Water added % 2.4 5.9 7.3 Moisture at compaction % 14.0 18.0 19.5 Height-of sample.. _IN......2.47 .2.552.57 Dry density PCF 119.0 109.4 107.5 R-Value by exudation 22 7 6 R-Value by exudation, corrected 22 7 6 Exudation pressure PSI 787 330 188 Stability thickness FT 1.70 2.021 2.051 _ Expansion pressure thickness FT 2.13 0.57 0.10 DESIGN CALCULATION DATA Traffic index, assumed 8.5 Gravel equivalent factor, assumed 1.25 Expansion, stability equilibrium 1.77 R-Value by expansion 19 R-Value by exudation 6 R-Value at equilibrium 6 Expansion, Stability Equilibrium 3.00 2.5O In in 1.50 i-1.00 0050 0.00 I" I I I I I I I I1 1I I I I I1 1I I I I 1 I 0.00 0.50 1.00 1.50 2.00 2.50 3.00 Cover Thickness by Expansion Pressure (ft) SAMPLE INFORMATION Sample Location: RV-2, Glen Av. Sample Description: Gray Sandy Clay Notes: 28+50-31+00 - 0% Retained on 3/4 inch sieve GeoSoils, Inc. ?S 5741 Palmer Way Carlsbad CA 92008 Telephone: (760) 438-3155 Fax: (760) 931-0915 R- VALUE TEST RESULTS Project: BROOKFIELD Number: 5353-El-SC Date: Oct-08 Plate: 2 - I. Traffic index, assumed 8.5 Gravel equivalent factor, assumed 1.25 Expansion, stability equilibrium 0 R-Value by expansion NA R-Value by exudation 20 R-Value at equilibrium 20 Expansion, Stability Equilibrium 2.00 1.50 U, U) 1.00 a) C.) 0.50 :.00l'I1 I III I II! liii 1 11111 0.00 0.50 1.00 1.50 2.00 Cover Thickness by Expansion Pressure (ft) TEST SPECIMEN A B C D Compactor air pressure PSI 260 220 130 Water added % 1.5 2.1 2.4 Moisture at compaction % 11.5 12.2 12.5 . . 2.44.-. .2.5.2.45. Dry density PCF 123.9 122.0 121.0 R-Value by exudation 23 21 14 Height.ofsample..........................................JN... R-Value by exudation, corrected 22 21 14 1.87. Exudation pressure PSI 475 330 193 Stability thickness FT 1.66 1.72 Expansion pressure thickness FT 0.33 0.20 0.00 DESIGN CALCULATION DATA SAMPLE INFORMATION GeoSoils, Inc. 77 5741 Palmer Way Carlsbad, CA 92008 ' Telephone: (760) 438-3155 Fax: (760) 931-0915 R - VALUE TEST RESULTS Project: BROOKFIELD Number: 5353-El-SC Date: Oct-08 Plate: 3 APPENDIX REFERENCES California Department of Transportation, 2006, Caltrans, Standard specifications, May printi.ng. Carlsbad, City of, 1993, Standards for design and construction of public works improvements in the City of Carlsbad. GeoSoils, Inc., 2007a, Pavement design report, Improvement of "loop" roads, Wind Trail Way, Glen Avenue, and Hilltop Street, Robertson Ranch East Village, City of Carlsbad, San Diego County, California 5384 oct 31, 2007 2007b, Pavement design report, Improvement (widening) of College Boulevard (Stations 103-+35 to 118), and Cannon Road (Stations 127 to 159), City of Carlsbad, San Diego County, California, W.O. 5354-E-SC, dated September 18. 2007c, Review of R-value data, Improvement (widening) of College Boulevard (Stations 103 to 118+10), and Cannon Road (Stations 127 to 159), City of Carlsbad, San Diego County, California, W.O. 5354-E-SC, dated September 4. 2004a, Revised pavement design report, College Boulevard Stations 78 to Reach C, Calavera Hills II, Carlsbad, San Diego County, California, W.O. 4028-E-SC, dated April 19, 2004, by GeoSoils, Inc. 2004b, Revised pavement design report, College Boulevard Stations 101+75 to 118 -i0 Reach B, Calavera Hills II, Carlsbad, San Diego County, California, W.O. 4029-.E-SC, dated April 23. 2004c, Third revision of 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 May 14. NEWCON90, 1991 Computer program for the determination of asphalt pavement sections, version: April 30. State of California, Department of Transportation, 2006, Highway design manual of instructions, sixth edition, September printing. GeoSoils, Inc.