HomeMy WebLinkAboutCT 04-26; ROBERTSON RANCH PA 16, 17 & 18; REVISED PAVEMENT DESIGN REPORT; 2009-12-24.FILE .
Geotechnical • Geologic • cdàstaI • Environmental
5741 Palmer Way Carlsbad, California 92010 (760) 438-3155 FAX (760) 931-0915
December 24 2009 )
flVILJ FLIUQly , JUJ A
William Lyon Homes, Inc.
4490 Von Karman Avenue
Newport Beach, California 92660
W.O. 5954-E-SC
Attention: Mr. John Lux
Subject: Revised Pavement Design Report, -Arapaho Way (Stations 10 to 20);
and Ocala Street (Stations 10+50 to 1 2 40 ), Portion of Planning Area 18 of
Robertson Ranch, Carlsbad, San Diego County, California
Dear Mr. Lux:
In accordance with your request and per City of Carlsbad reviewcomments, GeoSoi!s, Inc.
(GSI) has prepared these revised preliminary design and construction recommendations
for asphalt concrete '(AC) pavement at the subject site. The scope of services povidéd in
preparation of this revised report include a review of the referenced reports and documents
(see the Appendix),a review of the City of Carlsbad review comments, 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 the project
civil engineer; O'Day Consultants (personal communication). Pavement sections were
evaluated in general 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 following table), evaluated
from soils exposed at, or near, final subgrade elevations within the subject areas. R-valüe
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 O'Day as 5.0 for the subject traffic areas R-values
(see attached Figures 1 through 3) ranging from 6 to 15 were obtained for representative
subgrade soils onsite and used in pavement design The revised recommended pavement
sections are provided in general accordance with the City guidelines (City of Carlsbad,
1993) and review, commentary, and are presented in the following table:
APPROXIMATE TRAFFIC SUBGRADE THICKNESS
AGGREGATE
BASE THICKNESSt3
TRAFFIC AREA INDEX11 R-VALUE (Inches)2 (Inches)
'Arapaho, Stations 10 to 15 ' 5.0 ' 6 12.0(2)(4)
(Sample obtained from Station
12)
Arapaho, Stations 15 to 20 5.0 14 10.0(2)(4)
(Samples obtained from Station
18)
Ocala, Stations 10 to 12 5.0 15 10.0(2)(4)
(Sample obtained from Station -
Per O'Day Consultants
Exceeds City minimum, design per State of California (2006)
Denotes Class 2 Aggregate Base R >78, SE >25)
Thickness per City of Carlsbad recent review comments
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 The recommended pavement secti6ni provided above are intended as a
minimum guideline If thinner or highly variable pavement sections are constructed
increased maintenance and repair could be expected If the ADT (average daily traffic) or
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 e4, topcoat) Best management construction practices should be followed at all
times, especially during inclement weather
William Lyon Homes, Inc W 0 5954 E SC
Portion of Planning Area 18 Robertson Ranch Revised February 9-:2010
File e \wp9\5900\5949e rpdr GeoSoils, Inc. Page 2
1-
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 sübgrade 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 :111. accordance with
Section 26 of Caltrans Standard specifications (California Department of Transportation,
2006), for CaJtrans Class 2 aggregate base:
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.
4 The base is kept free of debris prior to placement of asphaltic concrete
William, Lyon Homes, Inc. ' .' ' ' 'W.O. 5954-E-SC
Portion of Planning Area 18 Robertson Ranch Revised February 9 2010
File e \wp9\5900\5949e rpdr Page 3 GeoSoils, Inc.
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. Due to the low R-values (6 to 15), wet subgrade conditions could significantly
reduce the performance of the pavement. It is imperative that subgrade materials are not
allowed to become wet or saturated. Over-watering of landscape areas should be avoided.
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. Line and grade of each layer of pavement compact is to be designed
by others.
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.
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.
William Lyon Homes, Inc. • W.O. 5954-E-SC
Portion of Planning Area 18, Robertson Ranch Revised February 9, 2010
File: e:\wp9\5900\5949e.rpdr
GeoSoils, Inc. Page 4
The opportunity to be of service is greatly appreciated. If you have any questions, please
do not hesitate to call our office.
ResPectfullYsUbrnAL'.\
•• I /?0FESSb0,VN
GeoSoils, Inc. ( 1934
Engineering No. Gq32p
t\\
(P Geologist
/4 'Robert G. Crisman Andrew T. Guatelli
Engineering Geologist, 934 Geotechnical Engineer,
RGC/ATG/JPF/jh
Attachments: Figures 1 through 3 - R-value Test Results
Figure 4 - Calculations -
Appendix - References S
Distribution: (2) Addressee
(2) Jobsite
..William Lyon Homes, Inc. • • : • W.O. 5954-E-SC
Portion of Planning Area 18 Robertson Ranch Revised February 9 2010
File e \wp9\5900\5949e rpdr Page 5
GeoSoils, Inc.
TT PP1IMPN A B C D
Compactor air pressure PSI 140 100 70
Water added 4.0 6.1 7.5
Moisture at compaction % 16.0 18.1 19.5
Height of sample IN 2.43 2.51 2.63
Dry density PCF 113.9 108.6 106.0
R-Value by exudation 12 6 4
R-Value by exudation, corrected 12 6 4
Exudation pressure PSI 572 304 243
Stability thickness FT 1.131 1.201 1.23
Expansion pressure thickness FT 1.371 0.501 000
DESIGN CALCULATION DATA
Traffic index, assumed 5.0
Gravel equivalent factor, assumed 1.25
Expansion, stability equilibrium 1.14
R-Value by expansion 11
R-Value by exudation 6
R-Value at equilibrium 1 6
Expansion, Stability Equilibrium
2.00
0.00-I''
0.00 0.50 1.00 1.50 2.00
Cover Thickness by Expansion Pressure (ft)
SAMPLE INFORMATION
Sample Location: Arapahoe 10+00-15+36
Sample Description: Gray Sandy Clay
Notes: FROM 12+20
0% Retained on 3/4 inch sieve
Test Method: Cal-Trans Test 301
R-Value By Exudation
80 -
70 --
60 -
50 --
CD
40 -
30 --
20--
0
800 700 600 500 400 300 200 100 0
Exudation Pressure (psi)
GeoSoils, Inc.
5741 Palmer Way
q4i14. Carlsbad, CA 92008
Telephone: (760) 438-3155
Fax: (760) 931-0915
R - VALUE TEST RESULTS
Project: WILLIAM LYON
Number: 5954-E-SC
Date: Dec-09 Figure: 1
TEST SPECIMEN A B C D
Compactor air pressure PSI 280 220 180
Water added % 0.3 1.8 2.8
Moisture at compaction % 10.5 12.0 13.0
Height of sample IN 2.43 2.48 2.55
Dry density PCF 124.1 120.3 116.7
R-Value by exudation 24 16 14
R-Value by exudation, corrected 23 16 14
Exudation pressure PSI 580 403 291
Stability thickness FT. 0.97 1.081 1.10
Expansion pressure thickness FT 0.731 0.271 0.00
DESIGN CALCULATION DATA
Traffic index, assumed 5.0
Gravel equivalent factor, assumed 1.25
Expansion, stability equilibrium 0
R-Value by expansion NA
R-Value by exudation 14
R-Value at equilibrium 14
SAMPLE INFORMATION
Sample Location: Arapahoe 15+36-20+00
Sample Description: Gray Sandy Clay
Notes: FROM 18+00
2% Retained on 3/4 inch sieve
Test Method: Cal-Trans Test 301
R-Value By Exudation
80 Expansion, Stability Equilibrium
2.00
'1.50
70
50
50
CO 1.00 a:
0.50
0.00 I I I I I I I
0.00 0:50 1.00 1.50 2.00
Cover Thickness by Expansion Pressure (ft)
A!i
10-
0
800 700 600 500 400 300 200 100 0
Exudation Pressure (psi)
GeoSoils, Inc. R - VALUE TEST RESULTS
.:.... . 5741 Palmer Way Project: WILLIAM LYON Ti . .Carlsbad, CA 92008
Telephone: (760) 438-3155 Number: 5954-E-SC
Fax: (760) 931-0915
Date: Dec-09 Figure: 2
TFST SPFCIMFPd A B C 0
Compactor air pressure PSI 280 230 180
Water added % 1.1 2.1 3.1
Moisture atcompaction % 11.0 12.0 13.0
Height of sample IN 2.44 2.47 2.5
Dry density PCF 123.6 121.4 117.1
R-Value by exudation 27 17 13
R-Value by exudation, corrected 25 17 13
Exudation pressure PSI 532 366 224
Stability thickness FT 0.931 1.061 1.11
Expansion pressure thickness I FT 1.071 0.531 0.30
DESIGN CALCULATION DATA
Traffic index, assumed 5.0
Gravel equivalent factor, assumed 125
Expansion, stability equilibrium 0.97
R-Value by expansion 24
R-Value by exudation 15
R-Value at equilibrium 1 15
Expansion, Stability Equilibrium
2.00
F.
.1.50
SAMPLE INFORMATION
Sample Location: Ocala 12+40 Join Exist. 10+50
Sample Description: Gray Sandy Clay
Notes: FROM 18+00
2% Retained on 3/4 inch sieve
Test Method: Cal-Trans Test 301
R-Value By Exudation
60
.0
ca
U,
>, .0
U, U) 1.00
_I
-. ~wmw CD 0.50
0.00 i/111 1 i ll III 111 I I I
0.00 0.50 1.00 1.50 2.00
Cover Thickness by Expansion Pressure (ft)
GeoSoils, Inc.
.,•. 5741 Palmer Way
Carlsbad, CA 92008
\_' r Telephone: (760)438-3155
Fax: (760) 931-0915
R - VALUE TEST RESULTS
Project: WILLIAM LYON
Number: 5954-E-SC
Date: Dec-09 Figure: 3
PAVEMENT SECTION CALCULATIONS PER CALTRANS (2006)
General Data/Input Information:
Traffic Index (1.1.) = 5.0
R-Value (R) = see Figures 1 through 3
Gravel Factor (GF) for Asphalt = 2.5
Gravel Factor (GF) for base = 1.1
T = thickness in inches
Formulas:
Gravel Equivalent (GE) = 0.0032 (100-11)(T.l.)(12 inches)
GE = (1 asphalt)(2.5) + (T base)(1 .1)
Calculations:
Arapaho Way (Stations 10+00 to 15+36)
GE = 0.0032 (94)(5.0)(12) = 18.05 inches
18.05 inches = (4 inches AC)(2.5) + (T base) (1 .1)
8.05 inches = (T base) (1.1)
T base = 7.32 inches (use 8 inches)
Arapaho Way (Stations 15+36 to 20 00)
GE = 0.0032 (86)(5.0)(12) = 16.13 inches.
16.13 inches = (4 inches AC)(2.5) + (T base) (1 .1)
6.l3 inches = (T base) (1.1)
T base • 5.57 inches (use 6.0 inches)
Ocala (Stations 10+50 to 12+40)
GE =0.0032 (85)(5.0)(12) = 16.32 inches
16.32 inches = (4 inches AC)(2.5) + (T base) (1.1) •
6.32 inches = (T base) (1.1)
I base = 5.74 inches (use 6.0 inches)
W.O. 5954-E-SC Figure 4
APPENDIX
REFERENCES
California Department of Transportation, 2006, Caltrans, Standard specifications, May
printing.
Carlsbad, City of, 1993, Standards for design and construction of public works
improvements in the City of Carlsbad.
GeoSoils, Inc., 2010, Supplemental pavement design report, pavement design report,
Arapaho Way (Stations 10 to 15), Portion of Planning Area 18 of Robertson
Ranch, Carlsbad, San Diego County, California, W.O. 5954-E-SC, dated'January21.
2009a, Pavement design report, Arapaho Way (Stations 10 to 20), and Ocala
Street (Stations 10 to 12) Portion of Planning Area 18 of Robertson Ranch,
Carlsbad, San Diego County, California, W.O. 5954-E-SC, dated December 24.
2009b, Pavement design report, Wind Trail Way (Stations 16 to 18), Alander
Court (Stations 1 2- to 1 9), and Cascade Street (Stations 1 to 15. 12), portion
of Planning Area 16 of Robertson Ranch, Carlsbad, San Diego County, California,
W.O. 5949-E-SC, dated December 2.
2008a; Memo, Clarification of pavement design report, Glen Avenue, Station 26+22
to the Cul Du Sac; Robertson Ranch East Village, City of Carlsbad, San Diego
County, California, W.O. 5353-B-SC, dated October 31.
2008b, Revised pavement design report, Glen Avenue, Station 26 to the Cul Du
Sac, Robertson Ranch East Village, City of Carlsbad, San Diego County, California,
W.O. 5353-El -SC, dated October 31.
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, W.O. 5384-E-SC, dated October 31.
2007b, Pavement design report, improvement (widening) of College Boulevard
(Stations 103 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 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
101+71 , Reach C, Calavera Hills II, Carlsbad, San Diego County, California,
W.O. 4028-E-SC, dated April 19.
GeoSoils, Inc.
2004b, Revised pavement design report, College Boulevard Stations 101 to
11 8+jq Reach B, Calavera Hills II, Carlsbad, San Diego County, California,
W.O. 4029-E-SC, dated April 23. S.
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.
NEWC0N90, 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. • •
Appendix
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