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Home My WebLink AboutCT 02-02; LA COSTA OAKS SOUTH NEIGHBORHOODS 3.10 & 3.11; PAVEMENT RECOMMENDATIONS; 2004-01-13GEOCON INCORPORATED Project No. 06105-52-12 January 13, 2004 Warmington Homes 701 Palomar Airport Road, Suite 300 Carlsbad, California 92009 Attention: Mr. Chuck Isbell GEOTECHNICAL CONSULTANTS V OF ARLS BAD APPROVED 0 WITH ADDtTONS Y DATE c-r02., 02-. 0 Subject: VILLAGES OF LA COSTA - THE OAKS SOUTH NEIGHBORHOODS 3.10 AND 3.11 SITIO SALVIA STATION 10+00 TO 16+60 CORTE ROMERO STATION 18+00 TO 21+60 CAMINO. CEREZA STATION 11+50 TO 23+25 AVENIDA MARAV]LLA STATION 18+80 TO 24+00 CORTE BRISA STATION 10+00 TO 12+45 CARLSBAD, CALIFORNIA PAVEMENT RECOMMENDATIONS Gentlemen: In accordance with your request, we have performed supplemental geotechnical services for the subject streets within Villages of La Costa - The Oaks South development. The scope of our services included obtaining representative subgrade soil samples within the street areas and performing Resistance Value (R-Value) tests. The purpose of our work was to provide pavement design recommendations. To aid in preparing this letter, we have reviewed the improvement plans entitled Improvement and Utility Plans for: Villages of La Costa - Neighborhoods 3.10 and 3. 11, prepared by Hunsaker & Associates, City of Carlsbad approval dated May 6, 2003 and our reports entitled Final Report of Testing and Observdtion Services Performed During Site Grading, Villages of La Costa - The Oaks South, Neighborhood 3.10, Carlsbad, California, dated July 23, 2003 (Project No. 06105-52-12) and Update Geotechnical Report, Villages of La Costa-The Oaks South, Neighborhood 3.11, Carlsbad, California, dated October 20, 2003 (Project No. 06105-52-12). Subgrade soils in the area are predominately sandy to clayey gravels and typically exhibit relatively low R-Value characteristics. Based on field observations and previous laboratory tests, subgrade materials possess an expansion potential of "low" to "medium" (Expansion Index of 90 or less) as defined by the Uniform Building Code (UBC) Table 18-I-B. R-Value laboratory tests were performed in accordance with ASTM D 2844-99 (California Test Method 301) and the laboratory test results are presented in Table I. It is our understanding that a Traffic Index (Ti) of 5.0 has been assigned to the subject streets. Based on the above information and laloratory testing, we recommend the pavement sections indicated in Table II. Pavement section calculations were performed in accordance with California Department of Transportation Highway Design Manual; Section 608.4 and the City of Carlsbad Minimum Structural Standard GS-17. Pavement section calculations are presented in Figure 1. These 6960 Flanders Drive 0 San Diego, California 92121-2974 0 Telephone (858) 558-6900 • Fox (858) 558.6159 recommended sections should be considered preliminary with final sections to be determined and approved by the City of Carlsbad. Furthermore, we understand that the City of Carlsbad requires lime treatment of subgrade soils when the R-Value is less than 12 However, it is the opinion of Geocon Incorporated that the lime treatment of subgrade soils along the subject roadway alignments is not feasible due to the amount of rock present near finish subgrade elevation. Therefore, a waiver of the lime treatment policy is requested. Prior to placing base material for roadways, .as well as curb and gutter, we recommend the upper 12 inches of subgrade be scarified, moisture conditioned as necessary, and compacted to a dry density of at least 95 percent of the laboratory maximum dry density near to slightly above optimum moisture content in accordance with ASTM D 1557-00. In addition, the Class 2 aggregate base should be compacted to a dry density of at least 95 percent of. the laboratory maximum dry density near to slightly above optimum moisture content. Asphalt concrete should be compacted to a density of at least 95 percent of the laboratory Hveem density in accordance with ASTM D .2726-96a. The upper 12 inches of subgrade soils beneath areas. to receive concrete sidewalks should be compacted to a dry density of at least 90 percent of the laboratory maximum dry density near to slightly above optimum moisture content. Fill soil and base lift thickness should not exceed 6 inches. Class 2 aggregate base and asphalt concrete should conform to the City of Carlsbad specifications. The performance of asphalt concrete pavement is highly dependent on providing positive surface drainage away from the edge of the pavement. Ponding of water on or adjacent to the pavement will likely result in pavement distress and subgrade failure. To reduce the occurrence for such situations, we recommend that a minimum drainage gradient of 1 percent be maintained for pavement surfaces Drainage from landscaped areas should be directed to controlled drainage structures. Should you have any questions regarding this correspondence, or if we may be of further service, please contact the undersigned at your convenience. S - Very truly yours, .'. GEOCON INCORPORATED eodacker1 291 RCE 63291 \ CIVW. SR:dmc Ar ^ As cr (2) Addressee (3/del) Warmington Homes (Job Site) Attentions Mr. Larry Catalano. (1) Hunsaker & Associates Attention: Mr. David Blalock 11 Project No. 06105752-12 -2 - January 13, 2004 TABLEI SUMMARY OF R-VALUE TEST RESULTS °ASTM D 2844-99 (CALIFORNIA TEST METHOD 301) Sample No. Location ' R-Value R-.i Sitio Salvia Station 10+00 to 13±50 16 R-2 Sitio Salvia- Station 13+50 to 16+60 11 R-3 Corte Romero Station 18+00 to 20+00 11 R-4 Corte Romero Station 20+00 to 21+60: 6 R-5 Corte Brisa Station 10+00 to 12+45 9 R-6 : Avenida Maravilla Station 18+80 to 21+40 11 R-7 Avenida Maravilla Station 21+40 to 24+00 9 R-8 Camino Cereza Station 11+50 to 14+50 14 R-9 Camino Cereza Station 14+50 to 17+50 13 R-10 Camino Cereza Station 17+50 to 20+50 . 12 R-11 Camino. Cereza Station 20+50 to 23+25 10. TABLE II PAVEMENT SECTION RECOMMENDATIONS -• Location - * • Traffic Index . * , Asphalt Concrete (inches) Class 2 Aggregate Base (inches) Sitio Salvia Station 10+00 to 13+50 , - ' 4. 6 Sitio Sãlvià Station 13+50 to 16+60 5.0 7. Corte Romero Station 18+00 to 20+00 5.0 4 7 Corte Romero Station 20+00 to 21+60 5.0 ' ' 4 8 Corte.Brisa Station 10+00 to 12+45 - ' 5.0 4 7' Avenida Maravilla Station 18+80 to 21+40 ' ., 5.0 ' '4 7 Avenida Maravilla Station 21+40to24+00 5.0'' '.4 7 Camino Cereza Station 11+50to14+50 ' _5.0 • 4 6 CaminoCerezaStation14+50to17+50 5.0 • '4. _' 7' CaminoCerezaStation17+50to20+50 5.0 '' 4 .7 CaminoCerezaStation20+50to23+25 5.0__• 4 . 7 Project No. 06105-52-12 • • • . , ' - 'January13, 2004 / FIGURE PAVEMENT SECTION CALCULATIONS VILLAGES OF LA COSTA - THE OAKS SOUTH Sitto Salvia - Station 10+00 to 13+50 Use subgrade R-Value = 16.0 Traffic Index (TI) = 5.10 Methodology=CALTRANS Highway Design Manul Section 608.4 Safety Factor = 0'.2 - Applied to Asphalt Concrete (AC) GE for AC = (0.0032)(5.0)(100778.0)+0.2.= .55 feet from Table 608 4B Highway Design Manual GE .55 feet for AC yields actual, thickness = 2.65 inches Use 4.0 inches ofAC —City Minimum. GE for 4 0 inches of AC = 83 feet GE for base =(O.0032)(5.0)(100-16.0) -.83 .51 feet from Table 608 4B Highway Design Manual with GF for Class 2 base = 11 Base thickness = 5.57 inches Usebase thickness =6.0inches Design Street Structural Section *** Asphalt Concrete Thickness = 4 0 inches Class 2 Aggregate Base Thickness = 6.0 inches. Sitio Salvia - Station 13+50 to 16+60 Usesubgrade R-Value = 1 1.0 Traffic Index (TI) = 5.0 Methodology = CALTRANS Highway Design Manual Section 608 .4 , Safety Factor = 0.2 - Applied to Asphalt Concrete (AC) -: GE for AC (0M032)(5.0)(100-78.0)+0.2 =.55 feet from Table 608 4B Highway Design Manual GE = .55 feet for AC yields actual thickness = 2.65 inches Use 4.0 inches of AC City Minimum GE for 4.0 inches of AC=.83 feet GE for base = (0.0032)(5.0)(100711.0) - 83 = 59 feet from Table 608 4B Highway Design Manual with GF for Class 2 base = 11 Base thickness = 6.44 inches Use base thickness = 7.0 inches . Design Street Structural Section *** Asphalt Concrete Thickness = 4.0 inches Class 2 Aggregate Base Thickness = 7.0 inches. Project No. 06105-52-12 January 13, 2004 / FIGURE 1 (Continued) PAVEMENT SECTION CALCULATIONS VILLAGES OF-LA COSTA— THE OAkS SOUTH Corte Romero- Station 18+00 to 20+00 Use subgrade R-Value = 11.0 Traffic Index (TI) = 5.0 Methodology = CALTRANS Highway Design Manual Section 608 4 Safety Factor =0.2 —Applied to Asphalt Concrete (AC) GE for AC = (0.0032)(5.0.)(100-78.0)t0.2 =.55 feet from Table 608 4B Highway Design Manual GE = 55 feet for AC yields actual thickness'= 165 inches Use 4.0 inches of AC - City Minimum GE for 4.0 inches of AC 83 feet GE for base = (0.0032)(5.0)(100-11.0) - .83.= .59 feet from Table 608 AB Highway Design Manual with GF for Class '2 base = 11 Base thickness = 6.44 inches Use base thickness = 7.0 iriôhes1 *** Design Street Structural Section *** Asphalt Concrete Thickness = 4 0 inches Class 2 Aggregate Base Thickness ,= 7.0 inches Corte Romero - Station 20+00 to 21+60 • Use subgrade R-Value = 6.0 Traffic Index (TI)= 5.0 Methodology CALTRANS Highway Design Manual Section 608.4 Safety Factor = 0.2 - Applied to Asphalt Concrete (AC) GE for AC -= (0 0032)(5 0)(100-78 0)+0 2 =.55 feet from Table 608.4B Highway Design Manual GE = 55 feet for AC yields actual thickness =,2-.65 inches Use 4.0 inches of AC - City Minimum GE for 4.0 inches of AC =.83 feet GE for'base.= (0.0032)( .0)(100- 6.0).- .83 = .67 feet from Table 608.4B Highway Design Manual with GF for Class 2 base = 11 Base thickness = .7 .32 inches • Use base thickness = 8.0 inches *** Design Street Structural Section Asphalt Concrete Thickness = 4.0 inches Class 2 Aggregate Base Thickness = 8.0 inches. Project No 06105-52-12 • - January 13, 2004 FIGURE 1 (Continued) PAVEMENT SECTION CALCULATIONS VILLAGES OF LA COSTA - THE OAKS SOUTH Corte Brisa - Station 10+00 to 12+45 Use subgrade R-Value = 9.0 Traffic Index (TI) =5.0 Methodology = CALTRANS Highway Design Manual Section 608.4 Safety FactOr = 0.2 - Applied to Asphalt Concrete (AC) GE for AC = (0.0032)(5.0)(100-78.0)+0.2.=.55 feet from Table 608.413 Highway Design Manual GE =55 feet for AC yields actual thickness = 2.65 inches Use 4.0 inches of AC - City 'Minimum GE for 4.0 inches of AC = .83 feet GE for base = (0.0032)(5.0)(100- 9.0) -.83 = .62 feet from'Table 608.4B Highway Design Manual with GF for Class 2 base = 1.1 Base thickness = .6.79 inches Use base thickness = 7.0 inches *** Design Street, Structural Section Asphalt Concrete Thickness = 4.0 inches. Class 2 Aggregate Base Thickness,= 7.0 inches. Avenida Maravilla - Station 18+80 to 21+40 Use subgrade R-Value = 11.0 Traffic Index (TI) = 5.0 ' Methodology = CALTRANS Highway Design Manual Section 608.4 Safety Factor = 0.2 - Applied' to Asphalt Concrete (AC) GE for AC = (0.0032)(5.0)(100-78.0)+0.2 =.55 feet from Table 608.413 Highway Design Manual GE = .55 feet for AC yields 'actual thickness = 2.65 inches Use 4.0 inches of AC - City Minimum GE for 4.0 inches of AC .83 feet GE for base = (0.0032)(5.0)(100-11.0) -.83 = .59 feet from Table;608.4B Highway Design Manual with GF for Class 2 base = 1.1 Base thickness = 6.44 inches Use base thickness = 7.0 inches *** Design Street Structural Section *** Asphalt Concrete Thickness = 4.0 inches. Class 2 Aggregate Base Thickness = 7.0 inches. Project No. 06105-52-12 ' . . ' ' January 13, 2004 FIGURE 1 (Continued) PAVEMENT SECTION CALCULATIONS VILLAGES OF LA COSTA - THE OAKS SOUTH, ,Avenida Maravilla - Station 21+40 to 24+00 Use subgradeR-Value = 9.0 Traffic Index (TI) = 5.0 S Methodology CALTRANS.Highway Design Manual Section 608.4 Safety Fáctor.= 0.2,- Applied to Asphalt Concrete (AC) GE for AC =(0.0032)(5.0)(100-78.0)+0.2= .55 feet from Table 608.4B Highway Design Manual GE .55 feet for AC yields actual thickness = -2.65 inches Use 4.0 inches of AC - City Minimum GE fOr4.0 inches of AC =.83 feet GE for base = (0.0032)(5.0)(100- 9.0) -.83 = .62 feet from-Table 608.4B Highway Design' Manual with GF for Class 2 base = 1.1. Base thickness .= 6.79 inches Use base thickness = 7.0 inches *** Design Street Structural Section *** Asphalt Concrete Thickness = 4.0 inches Class 2 Aggregate Base Thickness = 7.0 inches Camino Cereza - Station 11+50 to 14+50 Use subgrade R-Value = 14.0 Traffic Index (TI) = 5.0 - Methodology = CALTRANS Highway Design Manual Section 608.4 Safety Factor = 0 2 - Applied to Asphalt Concrete (AC) GE for AC = (0.0032)(5.0)(100-78.0)+0.2 = .55 feet from Table 608.4B1Highwày, Design Manual , - - GE = 55 feet for AC yields actual thickness = 2.65 inches Use4.0 inches of AC- City Minimum S GE for 4 0 inches of AC = 83 feet GE for base = (0.0032)( 5.0)(100-14.0) -.83 = .54 feet from Table 608:4B Highway Design Manual with GF for Class 2 base = 1.1 Base thickness = 5.92 inches S Use base thickness = 6.0 inches S *** Design Street Structural Section *** Asphalt Concrete Thickness = 4 0 inches Class 2 Aggregate Base Thickness 6.0 inches. Project Noi, 06105-52712 • January 13, 2004 FIGURE 1 (Continued) PAVEMENT SECTION CALCULATIONS VILLAGES OF LA COSTA - THE OAKS SOUTH Camino Cereza - Station 14+50 to 17+50 Use subgrade R-Value = 13.0 Traffic Index (TI) = 5.0 Methodology = CALTRANS Highway Design Manual Section 608 .4 , Safety Factor = 0.2 - Applied to Asphalt Concrete (AC) GE for AC = (0.0032)(5.0)(100778.0)+0.2 =.55 feet from Table 608.4B Highway Design Manual GE = .55 feet for AC yields actual thickness = 2.65 inches Use 4.0 inches of AC - City Minimum GE for 4.0 inches of AC = .83 feet GE for base = (0.0032)(5.0)(100-13.0) - .83 = .56 feet from Table 608.4B Highway Design Manual with GF for Class 2 base = 1.1 Base thickness = 6.09 inches Use base thickness,-- 7.0 inches *** Design Street Structural Section *** Asphalt Concrete Thickness = 4.0 inches. Class 2 Aggregate Base Thickness = 7.0 inches. Camino Cereza - Station 17+50 to 20+50 Use subgrade R-Value = 12.0 Traffic Index (TI) = 5.0 Methodology = CALTRANS Highway Design Manual Section 608.4 Safety Factor = 0.2 - Applied to Asphalt Concrete (AC) GE for AC = (0.0032)(5.0)(100-78.0)+0.2 =.55 feet from Table 608.4B Highway Design Manual GE = .55 feet for AC yields actual thickness = 2.65 inches Use 4.0 inches of AC - City Minimum GE for 4.0 inches of AC = .83 feet GE for base = (0.0032)( 5.0)(100-12.0) -.83 =.57 feet from Table 608.4B Highway Design Manual with GF for Class 2 base = 1.1 Base thickness = 6.27 incheS Use base thickness = 7.0 inches *** Design Street Structural Section *** Asphalt Concrete Thickness = 4.0 inches. Class 2 Aggregate Base Thickness = 7.0 inches. Project No. 06105-52-12 January 13, 2004 FIGURE 1 (Continued) PAVEMENT SECTION CALCULATIONS VILLAGES OF LA COSTA-- THE OAKS SOUTH Camino Cèreza - Station 20+50 to 23+25 Use. subgrade R-Value = 10:0 Traffic Index (TI) = 5.0 Methodology = CALTRANS Highway Design Manual Section 608.4 Safety Factor 0.2 Applied to Asphalt Concrete (AC) GE for AC (0.0032)(5.0)(100-78.0)+0.2 = .55 feet S from Table 608 4B Highway Design Manual GE = .55 feet 5for AC yields actual thickness = 2.65 inches Use 4.0 inches of AC - City Minimum 0 GE for 4.0 inches of AC = .83 feet . GE for base = (0.0032)( 5.0)(100-10.0) -.83 = 61 feet from Table 608 4B Highway Design Manual with OF for Class 2 base = 11 Base thickness 6.62 inches Use base thickness = 7.0 inches Design Street Structural Section Asphalt Concrete Thickness = 4.0 inches Class 2 Aggregate Base Thickness =-7.0 inches Project No 06105-52 12 January 13 2004