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Home My WebLink AboutCT 02-07; EMERALD POINTE ESTATES; REVISED PAVEMENT CROSS SECTION RECOMMENDATION; 2006-09-06No. 97-7189 6491 Geotechnical Exploration, Mc 01 SOIL AND FOUNDATION ENGINEERING . GROUNDWATER ENGINEERING GEOLOGY 6 September 2006 RWR Homes Inc. 2710 Loker Avenue West, Suite 350 Carlsbad, CA 92010 ttAn: hr. Brendan rarreiiy Subject: Revised Pavement Cross Section RecommendatiOn Emerald Pointe Estates Project, A.P.N. 212-040-50 North of the West End of Sapphire Drive Carlsbad, California * CITY OF CARLSBAD APPROVED LW WITH ADDITIONS 3 / BY DATE Dear Mr. Farrelly: As .requested, we have revised our letter dated August 24, 2006., Asper City of Caflsbad requirements, a representative of our company collected, one bulk sample of typical near- subgrade soils from the futur& Sapphire Drive extension into the project for R-value testing. We understand that this street has been'ässigned a Lnrespond Herein, we provide pavement cross-section recommendations based on the City of Carlsbad Standards' for Public and Private Streets, and the Flexible Pavement Structural Section Design Guide for California Cities and Counties by Caltrans. The pavement cross section has been defined based on the City of Carlsbad street traffic classification and the.11-value test result reported herein. TEST RESULT. . The bulk sample collected was taken on April 24, 2006 and the test completed on May 4, 2006 from typical subgrade soils encountered iñthe center of the length area of the street to be paved inside the project. The test was performed In conformance with (CTM N0.301) California Test Method No. 301. The Rvalue test yielded a value of R equal 11. The City of Carlsbad GS-17 Supplemental Standard for a cul-de-sac with a traffic index of 4.5 and R-value between 11 and 16 would require a pavement cross section of 4 inches of asphalt concrete on 4 inches of Class H base. It also requires that for soils with an _11-value of less than 12, the soils be treated with lime and retested to establish a new'R-vaiue. Since the project developer does not want to use lime treatment, we calculated based on the 7420 TRADE STREETS SAN DIEGO, CA. 92121 • (858) 549-7222 S FAX: (858) 549-16040. EMAIL:geoch@bcpres.com ' Emerald Pointe Estates .: Job No., 97-7189 Carlsbad, Cal iforni . . . Page 2 Caltrans procedure that the alternate section for untreated soils would be 4 inches of asphalt on 5 inches of Class II base material . . . . PAVEMENT CROSS SECTION RECOMMENDATION-. Based on the R-value test result and the City assigned traffic designation (cul-d6 sac with Traffic Index 4.5), we provide,-the following preliminary recommendations: , *1 /• Location ' - -Rccomandedcosp'SctIon " ... SapphireDrive cul- 4 inches Of asphalt concrete (A.C.) on ginchesof Class II de-sac . aggregate base on properly prepared and compacted subgrade soils (upper.1 foot). . . . . . . We understand that the project developer will add another, one, !rich .to the recommended Class II base material to hävé a total section of at least 4 inches of asphalt concrete (AX.) on 6 inches of Class II base material, rather than .'having to treat the 'subgrade soils with lime. . . ... . . . . . The City of Carlsbad. will still need to review the recommended cross section before the final, approved section is defined. Other. 'requirements by the City of Carlsbad are presented In the following section. . '. ••;•• ..• c' ; . ADDITIONAL SPECIFICATIONS Both the subgrade soil and the base,*material shall be properly compacted The subgrade shall be compacted to least 95 percent of laboratory maximum dry density and the base to at least 95 percent of maximum dry. density. The maximum dry density of the soil. and base material shall be determined in the. laboratory in. accordance with ASTM D1557-98. The, preparation and testing of.the subgrade, base, and asphalt pavement shell be done as specified in applicable portions of Section 30i and 302 of the wStandard Specifications for • . Public Works Construction, 2003 Edition" Class II aggregate base material should have an R-value not less .than 78, and a sand equivalent hot less than 30 (material passing sieve. #200 shall-Pot be more than-11 percent). Asphalt concrete mixture for the surface cot rse may only be C2 with asphalt cement grade AR4000, as required by the City of Carlsbad, in the public street area. Asphalt concrete CP 0 • . • . . ... .. • . ••. -4-. • _4_ - - . 1 - .•• -4 Etherald Pointe Estates Job No 97-7189 * Carlsbad, California Page ,3 shall be placid per applicable portions of Section 302 5 Asphalt Concrete Pavement of the-. "Standard Specifications for Public Works* Construct,on, 2003 'Edition.' The paving contractor shall also comply with Section 203-6 Asphalt Concrete Special Provision, presented in the "Standards for Design and Construction of Public Works Improvements in 4 4 the City of Carlsbad" : •: • ., LIMITATIONS. '- - .4 - . 4 - .- ... • -F 44 . - .• * - .. -. 1$ - .'. -4 *- .• ,--- . .4 •8_ • .- -.- - .•- '__4_ The findings and recommendations presented in this report have been made in accordance with curren1 generally accepted professional engineering principles and practice in the field of geotechnical engineering in the County. of,,San Diego No other warranty, either expressed or implied, is made 44 - -. .- •t- 4 . .4. _ - This opportunity to be of service is sincere lyappreciated Should you have any questions regarding this matter, please contact the undersigned 'Reference to our Job No 9777189 will help to expedite a response to your inquiries Respectfully submitted, 4- GEOTECHNICAL EXPLORATION, INC. - - - - R.C~E. 34422/G.E.,2007 e4 eer Org V4 4 1 09/11/2806 11:59 8585491604 GEl PAGE 03 CLIENTSAMPLE # : SAMPLE LOCATION SOIL TYPE R-VALUE 1 97-7189 R I / Emerald Pointe Estates Heavy Clay 11 PERFORMED IN GENERAL ACCORDANCE WITH ASTM 0284400 'R-VALUETESTRESULTS nor GEl / Sod & Material lab testing San Diego County, California f PROJECT NO DATE rFui 105626001 L 4/06 $-0218 RVTP,BLE * : * ?u01-2006 01 :04pm From-Hazard Construction +8584536034 I-L r.vu,uu, r-QSV r _.- - I P4MMUMSTRUCTURALSECT1ONININcHES Ti. t35(EWL) - ME i-.oE— 1.0CM. LIGHT C0NDARY MAJOR SUçRADF _SAC_ jTj - IN0US1frL R1AL I ARTF1tA1. PRIME AR1AL R—VALUE AC AR AC A8 AC AR AC AR ACI AB I AC AS ACI AR 8 4 7 4 13 415 10 4 1 5 4 118 1 5 18 1 6 18 12 4 6 4 12 4 14 14 4 -171 517 617 16 1 4 4 4 11 4 1 5 16 6 16 1 15 18 45 416 20 1 4 101 4 112 4 15 1 5 15 6 22 1 814 24 4 4 4 9 4 11 4 14 1 5 14 26 . 5 13 6 13 28 4 8 4 10- 4 13 30 5 12-1 6 12 32 '4 7 4 9412 611 34 4 11 5 11 36 L 4_-6..;. 4 8 - - - - - 6 10 - - 36 41051069. 42 49 6 B 44 . 46 58 46 ' 48 67 48 5768 50 - _4756 - 52 - 46 I. SOILS HAVING AN R VALUE LESS THAN 12 REQUIRE SPECIAL CONSIDERATiON, AN ALTERNATIVE TO INCREASING THE STRUCTURAL SECTION IS TO TEST FOR LIME STABILIZATION. THE CORRESPONDING STRUCTURAL SECTION DETERMINED AND % LIME ESTABLISHED. 2. A.B. ALL AGGREGRATE BASE MATERIALS SHALL BE CLASS II PER CALTRANS SECTION 26-1.02A OR CMB PER SECTiON 200-2.4 SSPWC. 3 THE BOTTOM FIGURES LISTED ARE THE MINIMUM PERMITTED. TOP It OF, SUB-GRADE TO BE 95% COMPACTION. PAVING SHALL BE DONE IN A MINIMUM OF iwo LIFTS WIN THE SURFACE COURSE DONE JUST PRIOR OCCUPANCY. THE BASE COURSE SHALL RE 2.50 NIH, 8. POTABLE. RECLAIMED WATER AND GAS, VALVE BOXES SHALL RE RAISED TO GRADE OR MADE ACCESSIBLE AT EACH PAVING LIFT AS APPROVED BY THE CITY ENGINEER. IF THE SEWER MAIN. IS IN SERVICE. THE ACCESSHOLE SHALL BE RAISED TO AT EACH PAVING LIFT. RAISING APPURTENANCES TO FS BEFORE AC CAP WILL NOT BE 'ALLOWED. RAISING VALVE BOXES, CIE NOUTS OR ACCESSORIES TO FiNISH GRADE BEFORE FINISH AC CAP IS PLACED WILL NOT BE ALLOWED. kREV.APPRO DATE CITY -OF CARLSBAD 604 STRUCTURAL SECTION I arf mw DAM OF STREETS AND ALLEYS GS-17