HomeMy WebLinkAboutCT 04-26; ROBERSTON RANCH PA 16, 17, 18; PAVEMENT DESIGN REPORT; 2012-06-22C-(oL - -t1,
Geotechnical . Geologic. Coastal. Environmental
5741 Palmer Way Carlsbad, California 92010 • (760) 438-3155 • FAX (760) 931-0915 • www.geosoilsinc.com
June 22, 2012
W.O.- 6302-E-SC
DR Horton :
12865 Pointe Del Mar, Suite 200
Del Mar, California 92014 . .
Attention: . Mr. Ryan Jaeger . . .
SUbject: Pavement Design Report, Glen Avenue (Stations 30 to Cul Du Sac),
Portion of Planning Area 18 of Robertson Ranch, Carlsbad, San Diego.
County, California
Dear Mr. Jaeger: . .
In accordance. with your request, GeoSoils, Inc. (GSI) has prepared this supplemental
pavement design report for asphalt concrete (AC) pavement at the subject site. This report
also includes alternative recommendations for the use of subgrade enhancement
geotextiles (SEG's), if desired. 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 (improvement plans). 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 theAppendix).
Pavement sections presented are based on the aforementioned criteria and resistance
value (R-value) data (see the attached Plates 1 and 2), 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. The collection of representative
subgrade samples was performed by a representative from this office. The number of
samples to be collected was determined by the City inspector. .
Structural Section
Traffic Indices (TI) were provided by the project civil engineer (O'Day Consultants, 2006)
as 5.0 for the subject traffic areas R-values (see attached Plates 1 and 2) ranging from 12
to 13 were evaluated for representative subgrade soils onsite and used, in pavement
design; . .
.
. . .
In addition to a standard asphalt over aggregate base pavement section, an alternative
section, using SEG's per Section 614.5 of the Highway Design Manual (State of California,
2012), and the State of.California (2009). The recommended pavement sections, provided
in general accordance with the City guidelines (City of Carlsbad, 1993), and the State of
California (2012, 2009), are presented as follows:
Standard Pavement Section: Asphalt/Aggregate Base
TABLE 1 ASPHALTIC CONCRETE (A.C.)IAGGREGATE BASE (A.B.)
APPROXIMATE
• . .. TI SUBGRADE THICKNESS THICKNESS TRAFFIC AREA .
-
R-VALUE
. (Inches) ' (inches)
Glen Aveune, Sta. to 32 (Sample
+25 5.0
obtained from Sta. 31 —)
13 4.0 7.0
Glen Avenue, Sta. 32+L5 to Cul du Sac
+ (Sample obtained from Sta. 32 ) 5.0 12 . 4.0 . 7.0
(')Per O'Day Consultants (Improvement plans) • . .
Minimum Per Carlsbad (1993) ,
Exceeds minimum Per Carlsbad (1993) . . . .
Denotes Class 2 Aggregate' Base R >78, SE >25)
DR Horton ,
Portion of PA 18, Robertson Ranch
File: e:\wp9\6300\6302e.pdr ' . GeOSOds, Inc.
W.O. 6302-E-SC
,June 22, 2012.
Page 2
Alternative Pavement Section: Subgrade Enhancement Geotextile (SEG)
TABLE 2 - ASPHALTIC CONCRETE (A.C.)/AGG REGAlE BASE (A.B.)/SEG
APPROXIMATE. Tit SUBGRADE A.C.
THICKNESS(3)
A.B.
THICKNESS 3'4
SEG CLASS
(CalTrans, TRAFFIC AREA . R-VALUE (2)
(Inches) (Inches) 2009)
Glen Avenue, Sta. 30tó 32
(Sample obtained from Sta. 5.0 20 4.0 5.0> Bi, B2 5
31 +L5) .
Glen Avenue, Sta. 32 to Cul
du Sac (Sample obtained from 5.0 20 4.0 . Bi, B2 5>.
Sta.32)
(')Per O'Day Consultants, (Improvement plans)
(2) Effective R-value when using SEG HP 570, or equivalent (State of California, 2008, 2009).
Per Carlsbad (1993)
Denotes Class 2 Aggregate Base R >78, SE 25)
Class Bi, Mirafi HP 570, or equivalent; Class B2, Mirafi FWSOO, or equivalent
This.alternative includes design pavement sections Using SEG's per Section. 614.5 of the
Highway Design Manual (State of California, 2012), and the State of California (2009).
Subgrade enhancement geotextile (SEG) used shall be either Mirafi HP 570 (Class Bi), or
FW500 (Class 132), or equivalent. All SEG's shall be placed per the manufacturers
guidelines.
General Installation Considerations
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 sections 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 equipnent and/or construction related heavy traffic.
(e.g., concrete trucks, ioaded 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,
DR Horton . . W.O. 6302-E-SC
Portion of PA 18, Robertson Ranch . GeoSoils, Inc June 22, 2012
File: e:\wp9\6300\6302e. pdr . Page 3
PAVEMENT GRADING RECOMMENDATIONS
General
All section changes shall-be properly tränsitioned. 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
Withinstreet 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 ft 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.
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.
3 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.
DR Horton W.O. 6302-E-SC
Portion of PA 18, Robertson Ranch June 22, 2012
File: e:\wp9\6300\6302e.pdr GeoSods, Inc. Page 4
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
geotechnical consultant.
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. Over-watering of
landscape areas should be avoided. Due to the low R-values, wet subgrade conditions
could significantly reduce the life of the pavement. Therefore, it is imperative that subgrade
materials are not allowed to become wet or saturated or allow water to flow into trenches
or behind curbs.
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.
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. GSl 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.
DR Horton W.O. 6302-E-SC
Portion of PA 18,.Robertson Ranch June 22, 2012
File: e:\wp9\6300\6302e.pdr GeoSoils, Inc. Page 5
The opportunity to be of service is greatly appreciated: If you have any questions, please
do not hesitate to call our office.
yOfESS!o
Respectfully submitted, '
GeoSoils, Inc. ' O. RCE 4785
kpJLL
Robert G. Crisman '. David W. Skelly OF C\-'
Engineering Geologist, CEG 1934 'Civil .Engineer, ACE 8
RGC/ATG/DWS/JPF/jh
Attachments: Plate 1 and 2'- R-value Test Results
* Appendix - References
Distribution: (4) Addressee .'
DR. Horton ' ' ' W.O. 6302-E-SC
Portion of PA 18 Robertson Ranch ' ' June 22, 2012
FiIe:e:\wp9\6300\6302e.pdr ' ' , Ge011s, Inc. ' Page 6
TEST SPECIMEN A B C D
Compactor air pressure PSI 210 150 90
Water added % S 3•7 4.7 . 5:7.
Moisture at compaction . . % 13.0 14.0 15.0
Height of sample . IN 2.45 2.47 2.51
Dry density . .. PCF 119.8 118.5 117.2
R-Value by exudation . . 25 15 9
R-Value by exudation, corrected 25 15
Exudation pressure . PSI 488 3421 249
Stability thickness FT . 0.96 1.09 1.16
Expansion pressure thickness FT 1.00 0.601 0.23
DESIGN CALCULATION DATA SAMPLE INFORMATION
Traffic index, assumed . . 5.0
Gravel equivalent factor, assumed 1.25
Expansion, stability equilibrium 0.98
R-Value by expansion 23
R-Value by exudation . 13
R-Value at equilibrium 13
Expansion, Stability Equilibrium
2.00
1.50
CD
Sample Location:. Glen Av. 30+80-32+25
Sample Description: Sandy Clay W/ Gravel
Notes:
41/6 Retained on 3/4 inch sieve
Test Method: Cal-Trans Test 301
R-Value By Exudation .
80
70
60
50
40
rz
15 >
30
20
10
' I I 1 I 0. . .
0.00 0.50 1.00 1.50 2.00 800 700 600 500 400 300 200 100 0
Cover Thickness by Expansion Pressure (ft) Exudation Pressure (psi)
GeoSoils, Inc.
5741 Palmer Way
-, .Carlsbad, CA92008
- Telephone: (760) 438-3155
Fax: (760) 931-0915
R - VALUE TEST RESULTS
Project: DR HORTON
Number: 6302-E-SC
Date: June 2012 Plate: 1
Sample Location: Glen Av. 32+26-End Road
Sample Description: Sandy Clay W/ Gravel
Notes:
9% Retained on 3/4 inch sieve
Test Method: ' ' Cal-Trans Test 301
R-Value By Exudation
50-
40 -
30-
20 -
10 -
0-
70-
60-
TEST SPECIMEN A C: n
Compactor air pressure PSI 220 170 110
Water added % 3.0 4.0 6.1
Moisture at compaction ' % 12.0 13.0 . 15.1
Height of sample ' IN , 2.45 2.47 2.52
Dry density ' ' ' PCF 120.0 118.9 115.1
R-Value by exudation ' 26 17 ' 10
R-Value by exudation, corrected 26 17 10
Exudation pressure PSI 508 387 282
Stability thickness FT 0.95 .1.061 1.15
Expansion pressure thickness FT 1.601 1.201 0.50
DESIGN CALCULATION DATA
Traffic index, assumed 5.0
Gravel equivalent factor, assumed 1.25
Expansion, stability equilibrium 1.08
R-Value by expansion , 16
R-Value by exudation 12
R-Value at equilibrium 12
Expansion, Stability Equilibrium
2.00
U) (1)1.00
0.50
I I I1 1 I I I I I
0.00 0.50 , 1.00 1.50 200
Cover Thickness by Expansion Pressure (ft)
SAMPLE INFORMATION
800 700 60P 500 400 300 200 100 0
Exudation Pressure (psi)
GeoSoils, Inc:
5741 Palmer Way
qlIfl'. Carlsbad, CA 92008
Telephone: (760) 438-3155
Fax: (760) 931-0915
R - VALUE TEST RESULTS
Project: DR HORTON
Number 6302-E-SC
Date: June 2012 Plate:' 2
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.
N EWCON9O, 1991 Computer program for the determination of asphalt pavement sections,
dated April 30. •
O'Day Consultants, 2006, Improvement plans for: Robertson Ranch East Village, City of
Carlsbad, Project no. C.T. 02-16, Drawing no. 433-6, dated December 29.
State of California, Department of Transportation, 2012, Highway design manual of
instructions, dated May 7. •
2009, Guide for designing subgrade enhancement geotextiles, dated April 28.
GeoSoils, Inc.
c-r04.2,ço
nee
Geotechnical ' Geologic. Coastal • Environmental
5741 Palmer Way • Carlsbad, California 92010 • (760)438-3155 • FAX (760)931-0915
Apri125, 2012
W.O. 5949-E-SC
Brookfield San Diego Builders, Inc.'
12865 Pointe Del Mar, Suite 200
Del Mar, California 92014
Attention.: Mr. Greg McDonnell
Subject: Pavement Design Report, Buck Ridge (Approximate Stations 10+00 to 16),
and Four Peaks (Approximate Stations 14+00 to 16+05 ), Planning Area 16 Of
Robertson Ranch, Carlsbad, San Diego County, California
Dear Mr. McDonnell:
In accordance with your request, GeoSoils, Inc. (GSI) has prepared this pavement design
report for asphalt concrete (AC) pavement at the subject site, to include recommendations
for the use of subgrade enhancement geotextiles (SEG's) and subgrade lime treatment,
as well as a modified, conventional asphaltic concrete over aggregate base section. The
scope of services provided in preparation of this report included 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 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 the attached Figures 1 and 2); evaluated from soils exposed at,
or near, final subgrade elevations within the subject area. 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
ATraffic Index (TI) was provided by the project civil engineer (O'Day Consultants) as 5.0 for
the subject traffic area. R-values (see attached Figures 1 and 2) of <10 were obtained
from representative samples of subgrade soil and used in pavement design. Where
"un-treated" R-values are less than 12, alternative pavement design is recommended by
the City (Carlsbad, 1993). The alternative methods included in our evaluation consisted
of the following:
Increase the minimum untreated aggregate base section to exceed the minimum
criteria for both Carlsbad (1993) and State of California (2008) for pavements on
subgrades. with R-values less than 12. See Table 1 herein.
Design pavement sections using SEG's per Section-614.5 of the Highway Design
Manual (State of California, 2008), the State of California (2009), and Mirafi (2005).
See Table 2 herein.
Design pavement sections using a lime treated subgrade per Carlsbad (1993),
Section 614.4 of the Highway Design Manual (State of California, 2008). See
Table 3 herein.
In consideration of cost, and environmental concerns regarding the use of lime, as well as
other aspects of lime use discussed in Mirafi (2005), increasing the overall base section
thickness, or using SEG's are preferred as an alternative to lime treatment, and have been
evaluated and approved by Caltrans, as well as the City of Carlsbad, in similar applications.
The recommended pavement sections, provided in general accordance with the City
guidelines (Carlsbad, 1993), and the State of California (2008, 2009), are presented as
follows:
Brookfield San Diego Builders, Inc. W.O. 5949-E-SC
PA 16 of Robertson Ranch GeoSoils,Inc. April 25,2012
File:e:\wpl2\5900\5949e.pdr6 Page 2
Pavement with Thickened Aggregate Base, Option A.
TABLE 1 - ASPHALTIC CONCRETE/AGGREGATE BASE
APPROXIMATE SUBGRADE AC.
THICKNESS
AGGREGATE
BASE THICKNESS(4) TRAFFIC AREA R-VALUE (Inches)13 (inches)
Buck Ridge. 10to 16 5.0 5 4.0 10.0(2)
(Sample obtained from Sta. 13)
Four Peaks. 14'L' to 16 5.0 8 4.0 .10.0(2) (Sample obtained from Sta. 15)
(')Per O'Day Consultants (Improvement plans)
Exceeds design per State of California (2008)
Per Carlsbad (1993)
Denotes Class 2 Aggregate Base R >78, SE >25)
This alternative includes increasing the minimum aggregate base section to exceed the
minimum criteria for both Carlsbad (1993) and State of California(2008). The aggregate
base thickness presented in Table '1 is approximately 125 percent of the minimum design
per State of California (2008).
Pavement with Subgrade Enhancement Geotextile (SEG), Option B.
TABLE 2 - ASPHALTIC CONCRETE/AGGREGATE BASE/SEG
APPROXIMATE SUBGRAD A.C.
THICKNESS
AGGREGATE
BASE THICKNESS 3
SEG CLASS
(CalTrans, TRAFFIC AREA R-VALUE (2)
(Inches) (inches) 2009)
Buck Ridge. 10to 16+L0
(Sample obtained from Sta. 5.0 20 4.0 5.0 131 4
13
Four Peaks. 14'22 to 16
(Sample obtained from Sta. 5.0 20 4.0 5.0 B1 4
15
(')Per O'Day Consultants (Improvement plans)
Effective R-value when using SEG HP 570, or equivalent (State of California, 2008, 2009)
Denotes Class 2 Aggregate Base R >78, SE >25)
Class Bi Mirafi HP 570, or equivalent
Brookfield San Diego Builders, Inc. W.O. 5949-E-SC
PA 16 of Robertson Ranch April 25, 2012 GeoSoils, Inc. FiIe:e:\wp12\59O0\5949epdr6 Page 3
This alternative includes a design pavement section using SEG's per Section 614.5 of the
Highway Design Manual (State of California, 2008), the State of California (2009), and Mirafi
(2005). Subgrade enhancement geotextile (SEG) used shall be MiraflHP 570 (Class Bi),
or equivalent. All SEG's shall be placed per the manufacturers guidelines.
Pavement with Lime Treated Subgrade, OptionC.
TABLE 3 -PRELIMINARY ASPHALTIC CONCRETE/AGGREGATE BASE/LIME TREATED SUBGRADE
AGGREGATE UNTREATED TREATED A.C. . BASE APPROXIMATE TI' SUBGRADE SUBGRADE THICKNESS THICKNESS(3) TRAFFIC AREA R-VALUE R-VALUE (Inches) (inches)
Buck Ridge. 10to 1699
(Sample obtained from Sta. 5.0 5 >60(2) 4.0 4.0
13
Four Peaks. 14+L0 to 16
(Sample obtained from Sta. 5.0 8 >60(2) 4.0 4.0
15
Per O'Day Consultants (Improvement plans)
Estimated R-value usind 3 to 4 percent Quicklime by weight.
Denotes Class 2 Aggregate Base R >78, SE >25)
This alternative includes a design pavement section using a lime treated subgrade per
Carlsbad (1993), and Section 614.4 of the Highway Design Manual (State of California,
2008). The treated R-values shown are an estimate based on previous testing performed
on similar subgrades within adjacent "Planning Areas" of Robertson Ranch (GSl; 2010a,
2010b, and 2010c). The minimum treated .subgradé thickness shall be 8 inches per
Carlsbad (1993). Lime treatment shall be per the standard of practice, and the National
Research Council (1987).
General Installation Considerations
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 provided above are intended as a minimum
guideline. If thinner or highly variable pavement sections are constructed, increased
maintenance and repair should be expected. If the ADT (average daily traffic) or ADIT
(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.
Brookfield San Diego Builders, Inc. W.O. 5949-E-SC
Planning Area 16, Robertson Ranch GSoi1s, Inc. Aril 25, 2012
File: e:\wp9\5900\5949e. pdr6 Page 4
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. W.O. 5949-E-SC
Planning Area 16, Robertson Ranch GO$O11S, Inc. April 25, 2012
File:e:\wp9\5900\5949e.pdr6 Page 5
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
geotechnical consultant.
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. Over-watering of
landscape areas should be avoided. Due to the low R-values, wet subgrade conditions
could significantly reduce the life of the pavement. Therefore, it is imperative that subgrade
materials are not allowed to become wet or saturated or allow water to flow or seep into
trenches or behind curbs.
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.
Brookfield San Diego Builders, Inc. W.O. 5949-E-SC
Planning Area 16, Robertson Ranch GeOSO11S Inc. April 25, 2012
File:e:\wp9\59OO5949e.pdr6 Page 6
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. GSl assumes
no responsibility or liability for work or testing performed by others, or their inaction,, or
work performed when GSl 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.
Brookfield San Diego Builders, Inc. W.O. 5949-E-SC
Planning Area 16, Robertson Ranch GSoi1s, Inc. April 25, 2012
File: e:\wp9\5900\5949e. pdr6 ' Page 7
The opportunity to be of service is greatly appreciated. If you have any questions, please
do not hesitate to call our office.
Respectfully su2jgT,..
GeoSoils, Inc.,
........c...
Robert G. Crisma(
Engineering Geolo1s1-t34
RGC/ATG/JPF/jh
"N
(LU (t'. C, G2
Andrew T. Guatell,
Geotechnical Engineer, GE 2320
Attachments: Figures 1 and 2 - R-value Test Results
Appendix - References
Distribution: (4) Addressee
Brookfield San Diego Builders, Inc. W.O. 5949-E-SC
Planning Area 16, Robertson Ranch April 25, 2012
F1Ie:e:\wp9\5900\5949e.pdr6 Page 8
TEST SPECIMEN A P
Compactor air pressure PSI 250 130 100
Water added % 5.6 6.6 8.1
Moisture at compaction. % 18.0 19.0 20.5
Height of sample IN 2.33 2.59 2.52
Dry density PCF 111.6 106.51 103.5
R-Value by exudation 15 9 7
R-Value by exudation, corrected 15 9 7
Exudation pressure PSI 678 336 219
Stability thickness FT 1 1.091 1.16 1.19
Expansion pressure thickness I FT 1 3.371 0.67 0.27
DESIGN CALCULATION DATA SAMPLE INFORMATION
Sample Location:. Four Peaks 15+00
Sample Description: Yellow Gray Sandy Clay
Notes: ROBERTSON'S RANCH PA-16
0% Retained on 3/4 inch sieve
Test Method: Cal-Trans Test 301
R-Value By Exudation
100 Expansion, Stability Equilibrium
4.00 S 90
3.50 80
.4- 70 .3.00
60 a, a
50
40
30
20
10
0. . .
0.00 1.00 2.00 3.00 4.00 800 700 600 500 400 300 200 100 0
Cover Thickness by Expansion Pressure (ft) Exudation Pressure (psi)
Traffic index, assumed 5.0
Gravel equivalent factor, assumed 1.25
Expansion, stability equilibrium 1.15
R-Value by expansion 10
R-Value by exudation 8
R-Value at equilibrium . 8
.0
u,2.50
>. .0
o2.00
0.50
0.00
GeoSoils, Inc.
5741 Palmer Way
Carlsbad, CA 92008
\L' '.tL2' • Telephone: (760) 438-3155
Fax: (760) 931-0915
R - VALUE TEST RESULTS
Project: BROOKFIELD
Number 5949-E-SC
Date: April 2012 Figure: 1
Traffic index, assumed 5.0
Gravel equivalent factor, assumed 1.25
Expansion, stability equilibrium 1.21
R-Value by expansion 5
R-Value by exudation 5
R-Value at equilibrium 5
Expansion, Stability Equilibrium
3.00
2.50
2.00
C')
0, 0,1.50 0,
U
i.-. 1.00
0 > 0
0050
0.00 (.'I I 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)
TEST SPECIMEN A R (. n
Compactor air pressure PSI 230 120 80
Water added % 3.9 5.9 8.1
Moisture at compaction % 18.0 20.0 22.2
Height of sample IN 2.48 2.53 2.61
Dry density PCF 107.8 104.5 99.6
R-Value by exudation . 12 8 4
R-Value by-exudation, corrected 12 8 4
Exudation pressure PSI 568 422 285
Stability thickness FT 1 1.131 1.181 1.23
Expansion pressure thickness FT 2.031 1.401 1.10
DESIGN CALCULATION DATA SAMPLE INFORMATION
GeoSoils, Inc.
7 5741 Palmer Way
Carlsbad, CA 92008
\. Telephone: (760)438-3155
Fax: (760) 931-0915
R- VALUE TEST RESULTS
Project: BROOKFIELD
Number 5949-E-SC
Date: April 2012 Figure: 2
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., 2010a, Pavement design report, MesaTrail (Stations 10-to 121-), portion
of Planning Area 21 of Robertson Ranch, Carlsbad, San Diego County, California,
W.O. 5981 -E-SC, dated February 17.
201 Ob, Revised pavement design report, Arapaho Way (Stations 10+00 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 February 9.
2010c, Supplemental pavement design report, Wind Trail Way (Stations 16 to
18'), Alander Court (Stations 12+00 to 19), and Cascade Street (Stations 12
to 152), portion of Planning Area 16 of Robertson Ranch, Carlsbad, San Diego
County, California, dated January 13.
2009, Pavement design report, Wind Trail Way (Stations 16 to 18), Alander
Court (Stations 12+00
to 19), and Cascade Street (Stations 12 +25 to 15), portion
of Planning Area 16 of Robertson Ranch,' Carlsbad, San Diego County, California,
W.O. 5949-E-SC, dated December 2.
2008, Memo, Clarification of pavement design report, Glen Avenue, Station 26 +30
to the Cul Du Sac, Robertson Ranch East Village, City of Carlsbad, San Diego
County, California, W.O. 5353-B-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.
Mirafi, 2005, Benefits of subgrade stabilization using geosynthetics versus lime treated soil,
Technical Note TN-LIME-0105, dated May 1.
National Research Council (U.S.). Transportation Research Board, 1987, Lime
Stabilization, State of the art Report 5, Committee on Lime and Lime-Fly Ash.
Stabilization, last modified September 25, 2009.
N EWCON9O, 1991 Computer program for the determination of asphalt pavement sections,
dated April 30.
GeoSoils, Inc.
State, of California, Department of Transportation, 2009, Guide for designing subgrade
enhancement geotextiles, dated April 28.
2008, Highway design manual of instructions, dated July 1.
Brookfield San Diego Builders, Inc. Geo$ojls, Inc. Fi1e:e:\wp9\5900\5949e.pdr6
Appendix
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