HomeMy WebLinkAboutCT 04-03; LA COSTA RIDGE NEIGHBORHOODS 2.3 & 2.4; PAVEMENT RECOMMENDATIONS CORTE PALOMA, SITIO CORDERO, SITIO MONTECILLO; 2005-12-05GEOCON
INCORPORATED
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Project No. 0720-52-04
December 5, 2005
Warmington Homes
701 Palomar Airport Road, Suite 280
Carlsbad, California 92009 . .
Attention: Mr. Chuck Isbèll
ciO4O3
GEOTECHNICAL CONSULTANTS -
SUBJECT: VILLAGES OF LA COSTA - THE RIDGE
NEIGHBORHOODS 2.3 AND 2.4 (SOUTH) .
CORTE PALOMA STATIONS 10+30 TO 16+30
SITIO CORDERO STATIONS 8+20 TO 16+20
SITIO MONTECILLO STATIONS 19+50 TO 29+50
CARLSBAD, CALIFORNIA
PAVEMENT RECOMMENDATIONS
Gentlemen:
In accordance with your request, we have performed supplemental geotechnical services for the
subject roadways within Villages of La Costa - The Ridge 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 Plans and Utility Plans for: La Costa Ridge - Neighborhoods 2.3 and 2.4 (South),
prepared by Hunsaker and Associates (Drawing No; 420-5A), City of Carlsbad approval dated
September 30, 2005, and our report entitled Update Geotechnical Investigation, Villages of
La Costa - The Ridge, Carlsbad, California, prepared by Geocon Incorporated, dated August 27,
2001 (Project No. 06015-52-05).
Subgrade soils in the area are predominately clayey fine sands and sandy to clayey gravels and
exhibit relatively low to high R-Value characteristics. Based on field observations and previous
laboratory tests, subgrade materials possess an expansion potential of "very low" to "low"
(Expansion Index of 50 or less) as defined by Uniform Building Code (UBC) Table 18-I-B. R-Value
laboratory tests were performed in accordance with ASTM D 2844-01 (California Test Method
No. 30 1) and the laboratory test results are presented on Table I.
Based on conversations with Hunsaker and Associates, the project civil engineer, we understand that
a Traffic Index (TI) of 5.0 has been assigned to the subject roadways. Based On the above information
and laboratory testing, we recommend the pavement sections indicated on 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 on Figure 1. These recommended sections should be
considered preliminary with final sections to be. determined and approved by the City of Carlsbad.
6960 Flanders Drive 0 San Diego, California 92121.2974 0 Telephone (85 8) 558-6900 0 Fax (858) 558-6159
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 1557-02. In addition, the Class ,2 aggregate base shall 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 shall be compacted to a density of at least 95 percent of the laboratory Hveem
density in accordance with ASTM D 2726-04. The upper. 12 inches of subgrade beneath areas to
receive concrete sidewalks shall be compacted to a dry density of 90 percent of the laboratory
maximum dry density near, to slightly above optimum moisture content. Fill soil and aggregate base
lift thickiiesses should not exceed 6 inches. Class 2 aggregate base and asphalt concrete shall 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. / •
. .
Very truly yours, • . . . . .
GEOCON INCORPORATED. •.• . .
C IN 0 .63291'
An RCE63291
SR:anh .CALI . .
. (2) Addressee . • . .
(3/del) Warmington Homes Jobsite Trailer •,
(1) Hunsaker and Associates • .
Attention: Mr. David Blalock .
.
Project No. 07290-52-04 - 2 - . • December 5, 2005
.5 .5.-..-
TABLE L
SUMMARY OF R-VALUE TEST RESULTS,
ASTM D 2844-01 /
(CALIFORNIA TEST METHOD NO. 301)
Sample Number Location , R-Value
R-1 .. Corte Paloma - Stations 10+30 to 13+30 ,. , 44
R-2 - Corte Paloma - Stations 13+30 to 16+30 22
R-3 Sitio Montecillo - Stations 26+50 to 29+50 71
R-4 ,- Sitio Montecillo Stations 23+50 to 26+50 70
R-5 Sitio Montecillo - Stations 19+50 to 23+50 18
R-6 Sitio Cordero - Stations 8+20 to 10+20 49
R-7 Sitio Cordero - Stations 10+20 to 13+20 22
R-8 . Sitio Cordero Stations 13+20 to 16+20 24
TABLED - -:
- . . PAVEMENT SECTON RECOMMENDATIONS '
S Location .• . -
Traffic
- Index'
(TI)
Asphalt
Concrete
(inches)
Class 2
Aggregate Base
(inches)
Corte Paloma - Stations 10+30 to 13+30 . 5.0 4 4
Corte Paloma - Stations 13+30 to 16+30 •, 5.0 4 ' 5
Sitio Montecillo - Stations 26+50 to 29+50 - 5.0 4 4
Sitio Montecillo - Stations 23+50 to 26+50 5.0 4 "
S
Sitio Montecillo - Stations 19+50 to 23+50 5.0 4 5
Sitio Cordero - Stations 8+20 to 10+20 - , 5.0 •' 4 4
Sitio Cordero - Stations 10+20 to 1120 5.0 4 ' 5
Sitio Cordero - Stations 13+20 to 16+20 - 5.0 4 4
•. • • •'•
FIGURE1
PAVEMENT SECTION CALCULATIONS
VILLAGES OF LA COSTA -THE RIDGE ••.
Corte Paloma - Stations 10+30 to 13+30
Use subgrade R-Value = 44.0 •
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 60814B 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)(100-44.0) .83 .06 feet
from Table 608.4B Highway Design Manual with GF for Class 2 base = 1.1
Base thickness .68 inches
Use base thickness = 4.0 inches, City of Carlsbad minimum
*** Design Street Structural Section
Asphalt Concrete Thickness = 4.0 inches.
Class 2 Aggregath Base Thickness = 4.0 inches.
Corte Paloma - Stations 13+30 to 16+30
Use subgrade R-Value = 22.0
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)(100-22.0) - .83 = .41 feet
from Table 608.4B Highway Design Manual with GF for Class 2 base = 1.1
Base thickness = 4.52 inches • • •
Use base thickness = 5.0 inches
*** Design Street Structural Section
• Asphalt Concrete Thickness = 4.0 inches.
Class 2 Aggregate Base Thickness = 5.0 inches.
Project No. 07290-52-04 December 51' 2005
FIGURE 1 (Continued)
PAVEMENT SECTION CALCULATIONS
VILLAGES OF LA COSTA -THE RIDGE
Sitio Montecfflo - Stations 26+50 to 29+50
Use subgrade R-Value = 71.0 •,
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)(100-71.0) - .83 =,-.37 feet
from Table 608.4B Highway Design Manual with GF for Class base = 1.1
Base thickness = -4.03 inches
Use base thickness = 4.0 inches, City of Carlsbad minimum
Design Street Structural Section
Asphalt Concrete Thickness = 4.0 inches.
Class 2 Aggregate Base Thickness = 4.0 inches.
Sitio Montecilo - Stations 23+50 to 26+50
Use subgrade R-Value = 70.0
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)(100-70.0) - .83 = -.35 feet
from Table 608.4B Highway Design Manual with GF for Class 2 base = 1.1
Base thickness = -3.85 inches
Use base thickness = 4.0 inches, City of Carlsbad minimum
*** Design Street Structural Section •
Asphalt Concrete Thickness = 4.0 inches. • • -
Class 2 Aggregate Base Thickness'-- 4.0 inches.
Project No. 07290-52-04 - December 5, 2005
FIGURE 1 (Continued)•
PAVEMENT SECTION CALCULATIONS
- VILLAGES OF LA COSTA - THE RIDGE
Sitio Montecfflo - Stations 19+50 to 23+50 •'
Use subgrade R-Value = 18.0 .
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)(100-18.0) - .83 .48 feet
from Table 608.413 Highway Design Manual with GF for Class 2 base = 1.1
Base thickness 5.22 inches - -
/
Use base thickness 5.0 inches '
*** Design Street Structural Section
Asphalt Concrete Thickness = 4.0 inches.
Class 2 Aggregate Base Thickness = 5.0 inches.
Sitio Cordèro - Stations 8+20 to '10+20
Use subgrade R-Value = 49.0 - -
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)(100-49.0) - .83 =' .02 feet
from Table 608.4B Highway Design Manual with GF for Class 2 base = 1.1
Base thickness = -.19 inches
Use base thickness = 4.0 inches, City of Carlsbad minimum
*** Design Street Structural Section
Asphalt Concrete Thickness = 4.0 inches. • '
Class 2 Aggregate Base Thickness = 4.0 inches.
Project No. 07290-52-04
- • December 5, 2005
FIGURE 1 (Continued)
PAVEMENT SECTION CALCULATIONS
VILLAGES OF LA COSTA-THE RIDGE
Sitio Cordero Stations 10+20 to 13+20
Use subgradê R-Value = 22.0
Traffic Index (TI) = 5.0
Methodology = CALTRANS Highway DesignManua1 Section 6Q8:4
Safety Factor = 0.2 -- Applied to Asphalt concrete (AC)
GE for AC = (0.0032)( 5.0)(10078.0)+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)(100-22.0)'- .83 .41 feet
from Table 608.4B Highway Design Manual with GF for Class 2 base = 1.1
Base thickness = 4.52 inches -
Use base thickness = 5.0 inches
Design Street Structural Section •
Asphalt Concrete Thickness 4.0 inches.
Class 2 Aggregate Base Thickness = 5.0 inches. •
Sitio Cordero - Stations 13+20 to 16+20 .. .• -
Use subgrade R-Value = 24.0
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
I
Use 4.0 inches of AC - City Minimum •
GE for 4.0 inches of AC = .83 feet .
GE for base = (0.0032)( 5.0)(100-24.0) - .83 = .38 feet
from Table 608.4B Highway Design Manual with GF for Class 2 base = 1.1
Base thickness = 4.17 inches
Use base thickness = 4.0 inches • • •- - .
Design Street Structural Section ***
Asphalt Concrete Thickness = 4.0 inches.
Class 2 Aggregate Base Thickness = 4.0 inches. •
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Project No. 07290-52-04 • • - - - December, 5, 2005 •
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