HomeMy WebLinkAbout3190; Rancho Sante Fe Road Wetland Mitigation; Rancho Sante Fe Road Wetland Mitigation; 2005-04-01'1*
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G-J T
E
LIMITED
GEOTECHNICAL INVESTIGATION
RANCHO SANTA FE ROAD
PROPOSED WETLANDS
MITIGATION AREA
SAN MARCOS, CALIFORNIA
PREPARED FOR
CITY OF CARLSBAD
% HELMING ENGINEERING, INC.
SAN MARCOS, CALIFORNIA
APRIL 1,2005
PROJECT NO. 05870-32-2 a
GEOCON
INCORPORATED
GEOTECHNICAL CONSULTANTS
Project No. 05870-32-22
April 1,2005
City ofCarisbad
^ % Helming Engineering, Inc.
1650 Linda Vista Drive, Suite 202
• San Marcos, Califomia 92078
Attention: Mr. Doug Helming
Subject: RANCHO SANTA FE ROAD
PROPOSED WETLANDS MITIGATION AREA
.1 SAN MARCOS, CALIFORNIA
LIMITED GEOTECHNICAL INVESTIGATION
•mm,
^ Gentlemen:
In accordance with your request and our proposal LG-05105 dated March 3, 2005, we have
« performed a limited geotechnical investigation for the proposed Wetlands Mitigation Area located
east of Rancho Santa Fe Road in San Marcos, Califomia. Specifically, the site is located northeast of
the Melrose Drive bridge crossing over San Marcos Creek (Vicinity Map, Figure 1). This study
"* focused on the proposed grading along the southeast bank of San Marcos Creek that extends
approximately 800 feet northeast of the Melrose Drive bridge.
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^ The purpose of this study was to evaluate the excavation characteristics of the deposits within the
area of proposed grading and obtain information regarding the materials expected to be encountered
during earthwork. The study also focused on the materials anticipated to be exposed in the proposed
2:1 (horizontahvertical) cut slope, including the stability of those materials. This study specifically
does not address check dam stability or design. The information presented herein is intended to assist
^ potential contractors in estimating the cost associated with grading the mitigation area as presently
^ proposed. Recommendations and specifications for site grading are also provided in this report.
/'
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** The project grading plan is entitled Wetlands Mitigation Area Grading Plans for: Rancho Santa Fe Rd. (Offsite Mitigation Site-Carlsbad Portion), prepared by O'Day Consultants, undated. The base Ml map for this study consists of a reproducible copy of a compilation of digital information provided by m O'Day Consultants (Geologic Map, Figure 2). The Geologic Map depicts the limited study area, existing topography, mapped geologic contacts, and the approximate locations of the exploratory trench excavations. The locations of exploratory trenches previously performed for an adjacent study to have also been included on the Geologic Map. Figure 3 presents three cross sections through the
6960 Flanders Drive • Son Diego, California 92I2I-2974 • Telephone (858) 558-6900 • Fox (858) 558.6159
ii
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proposed grading and depicts our interpretation of the underlying geologic conditions. The
conclusions and recommendations presented herein are based on an analysis of the data obtained
from the field investigation, previous work at the site, and our experience with similar soil and
geologic conditions.
Based on a review of the referenced project plan, the proposed site grading consists of removing the
majority of the existing embankment situated along the southeast side of San Marcos Creek to
accommodate a wider, sheet-graded channel for wetiand growth. The maximum cuts are anticipated
to be 25 feet with a maximum slope height of 30 feet. The slopes along this portion of the bank are
varied from 2:1 to 3:1 (horizontahvertical). The base of the channel is designed to flow from
northeast to southwest.
The scope of our services consisted of performing exploratory trenches along the southeast bank of
San Marcos Creek to evaluate the existing surficial deposits and to characterize the underlying
formational materials for rippability considerations. A total of 10 trenches were advanced on
March 15, 2005. The trenches were excavated to a depth of the proposed grade or to where refusal
was encountered. The excavations were performed utilizing a Link Belt 4300 trackhoe equipped with
a V-notch bucket. The materials encountered were visually examined, classified, and logged by a
geologist from our firm. The locations of the trenches are shown on the Geologic Map, along with the
previous pertinent trenches performed by our firm. Logs of the recent exploratory excavations are
presented on Figures A-l through A-10, Appendix A. The exploratory trench information from our
previous study has been included in Appendix B. A brief summary of the soil and geologic conditions
encountered is presented below.
The site geology consists of a three surficial deposits overlying Cretaceous-age granitic rock (refeixed
to as Escondido Creek Granodiorite). The surficial materials consist of a thin veneer of topsoil
overlying the granitic rock and a relatively thick, undocumented soil/rock embankment that is
believed to be associated with a mining operation that previously operated within the canyon. Based
on results of our previous study, a relatively thin deposit of alluvium occurs with the creek bottom,
which is in tum underlain by granitic rock. In general, the fills encountered in Trenches Tl through
^ T4, T6, and TIO can be characterized as loose, matrix-supported sands and gravels with 30 to 50
percent rock and a maximum dimension of^V2 feet. The fills encountered in the remaining trenches
** (T5 and T7 through T9), in general, can be described as loose, clast-supported rock fills with 20 to 40 te
percent fines and a maximum rock dimension of 4 feet. Severe caving was encountered in the
0H trenches where the material was clast supported. The alluvium encountered in the previous
1^ investigation ranged in thickness from IVz to IVi feet. With the exception ofthe proposed check dams
and a 6-foot-high, 3:1 cut slope, the alluvium is not anticipated to be encountered during site
^ construction.
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Project No, 05870-32-22 - 2 - April 1, 2005
The granitic rock encountered during this recent study consisted ofhighly to slighdy weathered, weak
to strong granitic rock. The majority of the trenches performed were able to reach the proposed
grades, with the exception of T2, T5, and T7. Practical refusal was encountered in T2 at 18 feet,
5 feet above the proposed grade. Severe caving of the undocumented fills overlying the granitic rock
prevented a thorough evaluation of the rock rippability in Trenches T5 and T7.
CONCLUSIONS AND RECOMMENDATIONS
1. No soil or geologic conditions were encountered which, in our opinion, would preclude the
grading of the channel, as presentiy planned, provided the recommendations of this report
are followed.
2. All grading should be perfomied in accordance with the attached Recommended Grading
Specifications (Appendix C). Where the recommendations of this section conflict with
Appendix C, the recommendations of this section take precedence. All earthwork should be
observed and all fills tested for proper compaction by Geocon Incorporated.
3. Prior to commencing grading, a preconstruction conference should be held at the site with
the owner or developer, grading contractor, civil engineer, and geotechnical engineer in
attendance. Special soil handling and the grading plans can be discussed at that time.
4. Site preparation should begin with the removal of surface deleterious material and
vegetation. The depth of removal should be such that material exposed in the cut areas or
soils to be used as fill are relatively free of organic matter. Objectionable debris such as
plastic or trash exposed in slope excavations should also be removed. Material generated
during stripping should be exported from the proposed grading area.
5. In areas to receive fill, the existing ground surface should be scarified, moisture
conditioned and compacted. The site should then be brought to fmal elevations with
^ structural fill compacted in layers. In general, soils native to the site are suitable for re-use
In as fill if relatively free from vegetation, debris, and other deleterious material. Oversized
rock fragments should be placed in areas beyond future proposed surface or subsurface
* improvements, or should be hauled away from the grading area. Compacted fill should be
to
placed in layers no thicker than will allow for adequate bonding and compaction. All fill,
m including backfill and scarified ground surfaces, should be compacted to least 90 percent of
IM» maximum dry density near optimum moisture, as detennined in accordance with ASTM
Test Procedure D 1557-91.
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Project No. 05S70-32-22 ~ April 1,2005
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In our opinion, the surficial deposits and the majority of the formational material can be
excavated with moderate to heavy effort with conventional heavy-duty grading equipment.
Oversize materials within the undocumented fill and granitic rock will require special
handling and placement in accordance with the recommendations provided in Appendix C.
The rippability conditions at the toe of the proposed cut slope, in the vicinity of
Trenches T2, T5, and T7 are unknown. The potential exists that very heavy effort and
possibly blasting may be necessary depending on the degree of weathering of the rock.
The proposed fill slopes constructed of the existing materials should have calculated factors
of safety in excess of 1.5 under static conditions for both deep-seated failure and shallow
sloughing conditions. All slopes should be compacted by track walking with a dozer upon
completion such that the fill soils are uniformly compacted to at least 90 percent relative
compaction to the face of the fmished slope.
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9. Based on our analysis ofthe tlii'ee cross sections (Figure 3), it appears that the majority of
the undocumented fill soils will be removed within the proposed cut slopes. Cut slopes that
expose granitic rock should possess a factor of safety greater than 1.5 for surficial and
deep-seated conditions provided they are free of adverse jointing. Undocumented fill may
be exposed within the upper portions of the cut slopes at isolated locations, Where this
occurs, these ai'eas will be evaluated during the grading phase of development to determine
if they are suitable in-place or if stability fills will be required.
10. With the exception of the mitigation area, all slopes should be landscaped with
drought-tolerant vegetation, having variable root depths and requiring minimal landscape
irrigation. In addition, all slopes should be drained and properly maintained to reduce
erosion.
If you have any questions regarding this report, or if we may be of further service, please contact the
undersigned at your convenience.
Very truly yours,
GEOCON INCORPORATED
Troy K^^Reist
Senior Staff Geologist
TKR:MEE:DBE:anh
(8) Addressee
Project No. 05870-32-22 -4 -April 1.2005
SOURCE: 2005 THOMAS BROTHERS MAP
SAN DIEGO COUNTY, CALIFORNIA
REPRODUCED WITH PERMISSION GRANTED BY THOMAS BORTHERS MAPS.
THIS MAP IS COPYRIGHT BY THOMAS BROS. MAPS. IS UNLAWFUL TO COPY
OR REPRODUCE ALL OR ANY PART THEREOF, WHETHER FOR PERSONAL USE OR
RESALE, WPTHOUT PERMISSION.
N
NO SCALE
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GEOCON
INCORPORATED
m
GEOTEOINICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159
m
JRI MM DSK/GTYPD
VICINITY AAAP
RANCHO SANTA FE ROAD
PROPOSED WETLANDS - MITIGATION AREA
SAN MARCOS, CALIFORNIA
DATE 04-01-2005 PROJECTNO. 05870 -32-22 FIG. 1
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» APPENDIX A
p. LOGS OF TRENCHES
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FOR
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PROPOSED WETLANDS MITIGATION AREA
; SAN MARCOS, CALIFORNIA
PROJECT NO. 05870-32-22
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PROJECTNO. 05870-32-22
DEPTH
IN
FEET
SAMPLE
NO.
SOIL
CLASS
(USCS)
TRENCHT 1
ELEV. (MSL.) _
EQUIPMENT
380' DATE COMPLETED 03-15-2005
LINK BELT 4300 TRACKHOE
ID -r-O \-
Z U;
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D
- 0 MATERIAL DESCRIPTION
- 2 -
- 4 -
- 6 -
- 10 -
SM
- +
+ + +
-f-+ +
- +
UNDOCUMENTED FILL
Loose, dry to damp, brown, SUty SAND, with 30-40% rock up to 36-inches
(matrix supported)
GRANITIC ROCK
Moderately weathered, tan, moderately strong to strong GRANITIC ROCK.
-Difficult trenching below 8 feet
-Very difficult trenching below 10 feet
TRENCH TERMINATED AT 11 FEET
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Figure A-1,
Log of Trench T 1, Page 1 of 1
05870-32-22,GPJ
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SAMPLE SYMBOLS n ... SAMPLING UNSUCCESSFUL B ... STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED) SAMPLE SYMBOLS
^ ... DISTURBED OR BAG SAMPLE B ...CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECTNO. 05870-32-22
DEPTH
IN
FEET
SAMPLE
NO.
SOIL
CUSS
(USCS)
TRENCHT 2
ELEV, (MSL.) 377'
EQUIPMENT
DATE COMPLETED 03-15-2005
LINK BELT 4300 TRACKHOE
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Z u.
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- 0
MATERIAL DESCRIPTION
- 2 -
- 4 -
- 6 -
- 10 -
- 12 -
- 14 -
- 16 -
- II
Kl
- -V
-f- + + + + +
UNDOCUMENTED FILL
Loose, moist to wet, brown, Silty SAND, with 40-50% rock up to 36-inches
(matrix supported)
SM
GRANITIC ROCK
Moderately weathered, tan, moderately strong to strong GRANITIC ROCK
-Becomes slightly weathered and strong below 17 feet (difficult trenching)
PRACTICAL REFUSAL AT 18 FEET
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Log of Trench T 2, Page 1 of 1
te SAMPLE SYMBOLS ° •.• SAMPLING UNSUCCESSFUL |] ...STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE K ...CHUNK SAMPLE I ... WATER TABLE QR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDiTIONS AT OTHER LOCATIONS AND TIMES.
PROJECTNO. 05870-32-22
DEPTH
IN
FEET
SAMPLE
NO.
SOIL
CLASS
(USCS)
TRENCH T 3
ELEV. (MSL.) 372-
EQUIPMENT
DATE COMPLETED 03-15-2005
LINK BELT 4300 TRACKHOE
Qo\-
H Z UL
I— w >
CO T
Z u-
St
D
- 0
MATERIAL DESCRIPTION
- 2 -
- 4 -
- 6 -
- 10 -
12 -
- 14 -
- 16 -
- 18 -
- 20
- + + + +
4-
-I-
+ +
SM
UNDOCUMENTED FILL
Loose, moist to wet, brown, Silty SAND, with 40-50% rock up to 40-inches
(matrix supported)
GRANITIC ROCK
Moderately weathered, tan, moderately strong GRANITIC ROCK
-Difficult trenching below 18 feet
TRENCH TERMINATED AT 20 FEET
Figure A-3,
Log of Trench T 3, Page 1 of 1
05B70-32-22.GPJ
SAMPLE SYMBOLS Q ... SAMPLING UNSUCCESSFUL E. . STANDARD PENETRATION TEST • . DRIVE SAMPLE (UNDISTURBED) SAMPLE SYMBOLS
^ ... DISTURBED OR BAG SAMPLE E .CHUNK SAMPLE . WATER TABLE DR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECTNO, 05870-32-22
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P
DEPTH
IN
FEET
SAMPLE
NO.
SOIL
CLASS
(USCS)
TRENCH T 4
ELEV. (MSL) 380-
EQUIPMENT
DATE COMPLETED 03-15-2005
LINK BELT 4300 TRACKHOE
I- z u.
1- CO >
^co 3
1^-
CO
Z U-
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- 0
MATERIAL DESCRIPTION
- 2 -
- 4 -
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SM
UNDOCUMENTED FILL
Loose, moist, brown, Silty SAND, with 10% rock up to 12-inches
q 1
SM/SC TOPSOIL
Loose, moist. Silty/Clavev SAND
-I- +
-I-
GRANITIC ROCK
Moderately weathered, tan, moderately strong GRANITIC ROCK
TRENCH TERMINATED AT 5 FEET
Figure A-4, 05870-32-22 GPJ
Log of Trench T 4, Page 1 of 1
SAMPLE SYMBOLS ^ ^ --^-^osssfu. |] ...STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED)
^ .. DISTURBED OR BAG SAMPLE K ...CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
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NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
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DEPTH
IN
FEET
P
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SAMPLE
NO.
SOIL
CLASS
(USCS)
TRENCHT 5
ELEV. (MSL.) 375'
EQUIPMENT
DATE COMPLETED 03-15-2005
LINK BELT 4300 TRACKHOE
Q o I-b 2: it
I- CO >
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Z u-
Q
- 0 MATERIAL DESCRIPTION
- 2 -
- 4 -
- 6 -
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- 10 -
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Q ol
> .CD 1^
Qold
GM
UNDOCUMENTED FILL
Loose, dry, ROCK FILL, with 20-30% fmes; rocks up to 40-inches (clast
supported)
-Heavy caving
-Severe caving
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TRENCH TERMINATED AT 11 FEET
DUE TO CAVING
Figure A-5, 05870-32-22.GPJ
Log of Trench T 5, Page 1 of 1
SAMPLESYMBOLS • .SAMPLING UNSUCCESSFUL |] ... STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED)
^ .. DISTURBED OR BAG SAMPLE E ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
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L NOTE; THE LOG QF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING QR TRENCH LOCATION ANO AT THE DATE INDICATED IT
IS NOT WARRANTED TQ BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT QTHER LOCATIONS AND TIMES.
PROJECTNO. 05870-32-22
DEPTH
IN
FEET
SAMPLE
NQ
SOIL
CLASS
(USCS)
TRENCHT 6
ELEV. (MSL.) 376-
EQUIPMENT
DATE COMPLETED 03-15-2005
LINK BELT 4300 TRACKHOE
< CO
CO ^
>-t
CO
Q
- 0 MATERIAL DESCRIPTION
- 2 -
- A -
- 6 -
- 10
- 12
UNDOCUMENTED FILL
Loose, moist, Silty SAND, with 30% rock up to 30-inches (matrix supported)
SM -Little to no rock present below 5 feet
+ + GRANITIC ROCK
Highly weathered, tan to brown, weak to moderately weak GRANITIC ROCK
TRENCH TERMINATED AT 12 FEET
Figure A-6, 05870-32-22. GPJ
Log of Trench T 6, Page 1 of 1
SAMPLE SYMBOLS ° ^ ''"'^'^^ -SUCCESSFUL B .. STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE [UNDISTURBED)
^ .. DISTURBED QR BAG SAMPLE K ...CHUNK SAMPLE X - VWATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOVW HEREON APPLIES QNLY AT THE SPECIFIC BORING QR TRENCH LOCATION AND AT THE DATE INDICATED IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
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DEPTH
IN
FEET
SAMPLE
NO
SOIL
CLASS
(USCS)
TRENCH T 7
ELEV. (MSL.)
EQUIPMENT
374' DATE COMPLETED 03-15-2005
LINK BELT 4300 TRACKHOE
Q U I-I- Z LL
H to >
^ CoS
CO
Z Ul.
St cc a
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- 2 -
- 4 -
- 6 -
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P
ll
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if
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P
ll
- 10
ct QiQt
d
QJQ
GM
MATERIAL DESCRIPTION
UNDOCUMENTED FILL
Loose, dry, ROCK FILL, with 20-30% fmes; rocks up to 48-inches (clast
supported)
-Moderate caving at 5 feet
-Severe caving at 9 feet
(P
P
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TRENCH TERMINATED AT 10 FEET
DUE TO CAVING
Figure A-7, 05870-32-22.GPJ
Log of Trench T 7, Page 1 of 1
.-r,. r- .r-.^, ^ D - SAMPLING UNSUCCESSFUL
SAMPLE SYMBOLS
B ... STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE K ... CHUNK SAMPLE I ... WATER TABLE QR SEEPAGE
i, NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING QR TRENCH LOCATION AND AT THE DATE INDICATED IT
^ IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT QTHER LOCATIONS AND TIMES.
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k PROJECT NO. 05870-32-22
DEPTH
IN
FEET
SAMPLE
NO.
SOIL
CLASS
(USCS)
TRENCH T 8
ELEV. (MSL.)
EQUIPMENT
370' DATE COMPLETED 03-15-2005
LINK BELT 4300 TRACKHOE
Q U H
I— Z LL
I— CO >
1^-
CO T Z u-
a: a
- 0
- 2 -
- 4 -
- 6 -
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P
F
In
TO
> icb I
doict
MATERIAL DESCRIPTION
UNDOCUMENTED FILL
Loose, dry to damp, ROCK FILL, with 20-40% fmes; rocks up to 48-inches
(clast supported)
GM
-Severe caving at 6 feet
TRENCH TERMINATED AT 7 FEET
DUE TO CAVING
^ Figure A-8,
Log of Trench T 8, Page 1 of 1
05870-32-22.GPJ
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL D . STANDARD PENETRATION TEST • . DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE B. .CHUNK SAMPLE . WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES QNLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED IT
IS NOTWARRANTED TO BE REPRESENTATIVE DF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 05870-32-22
DEPTH
IN
FEET
SAMPLE
NO.
SOIL
CLASS
(USCS)
TRENCHT 9
ELEV. (MSL.) 374'
EQUIPMENT
DATE COMPLETED 03-15-2005
LINK BELT 4300 TRACKHOE
Q u h I- z t
^- CO > ^co2
to --r Z U.
Q
- 0
MATERIAL DESCRIPTION
- 2 -
- 4 -
6 -
- 10 -
UNDOCUMENTED FILL
Loose, moist, dark brown, Silty SAND (topsoil)
SM
> .CD l'i
doCt
go!?
> -CD ]'
d nlCl
Loose, moist, ROCK FILL, with 30-40% fines; rocks up to 48-inches (clast
supported)
GM
-Severe caving below 10 feet
TRENCH TERMINATED AT 11 FEET
DUE TO CAVING
Figure A-9, 05870-32-22. GPJ
Log of Trench T 9, Page 1 of 1
SAMPLE SYMBOLS ° ''—— |] . . STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE K ...CHUNK SAMPLE % - WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING QR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECTNO. 05870-32-22
k
P
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P
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DEPTH
IN
FEET
SAMPLE
NO.
SOIL
CUSS
(USCS)
TRENCH T 10
ELEV. (MSL.) 375-
EQUIPMENT
DATE COMPLETED 03-15-2005
LINK BELT 4300 TRACKHOE
UJ — o I-
Z U;
co2
CO T Z U.
Q
- 0 MATERIAL DESCRIPTION
- 2 -
- 4 -
- 6 -
b
p
-0
UNDOCUMENTED FILL
Loose, dry to damp, Silty SAND, with 20% rock up to 24-inches (matrix
supported)
SM
SM TOPSOIL
Loose, damp, dark brown, Silty SAND
- +
+ -
GRANITIC ROCK
Highly weathered, tan, moderately weak GRANITIC ROCK
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TRENCH TERMINATED AT 9 FEET
Figure A-10, 05870-32-22. GPJ
Log of Trench T 10, Page 1 of 1
SAMPLE SYMBOLS ° • SAMPLING UNSUCCESSFUL |1 . STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE t .. CHUNK SAMPLE ... WATER TABLE OR SEEPAGE
NOTE. THE LOG OF SUBSURFACE CONDITIONS SHOVW HEREON APPLIES ONLY AT THE SPECIFIC BORING QR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
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APPENDIX B
EXPLORATORY TRENCHES PREVIOUSLY
PERFORMED BY GEOCON INCORPORATED
FOR
RANCHO SANTA FE ROAD
PROPOSED WETLANDS MITIGATION AREA
SAN MARCOS, CALIFORNIA
PROJECT NO. 05870-32-22
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PROJECT NO. 05870-32-05
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DEPTH
lti
FEET
SAHPLE
KO.
>-CD O _l O X
i-
H
SOIL
CLASS
CUSCS)
TRENCH T 2
ELEV. (MSL.) 371
EQUIPMENT
DATE COMPLETED
JD 555 TRACKHOE
9/1/00
LU
IN
LU ICQ
a
tr a
- 0 MATERIAL DESCRIPTION
- 2 -
- 4 -
- 6 -
- 10
.1-
SM/GM
.1- M-
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•1'
j'f
UNDOCUMENTED FILL
Loose, dry, brown to yellow-brown, Silty, fine to
coarse SAND, with abundant gravel and cobble
size angular rock fragments. Very difficult to
excavate due to abundant rock fragments
-Predomnantly clasj supg^orted_ _
-Primarily 12 inch to 36 inch-i- fragments below 3
feet, difficult excavating
TRENCH TERMINATED AT 10.5 FEET
Figure A-2, Log of Trench T 2 UC0M1
m SAMPLE SYMBOLS . SAMPLING UNSUCCESSFUL E. . STANDARD PENETRATION TEST K . . DRIVE SAMPLE (UNDISTURBED)
m . DISTURBED OR BAG SAMPLE B. . CHUNK SAHPLE I . . WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS ANO TIMES.
PROJECT NO. 05870-32-05
IK
m
DEPTH
IN
FEET
SAMPLE
NO.
>• CD O _1 O X
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SOIL
CLASS
(USCS)
TRENCH T 4
ELEV. (MSL.) 375
EQUIPMENT
DATE COMPLETED 9/1/00
JD 555 TRACKHOE
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- 0 MATERIAL DESCRIPTION
- 2 -
- 4 -
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UNDOCUMENTED FILL
Loose, dry, Silty, fine to coarse SAND from 0-6
inches
Clast supported with gravel, cobble and boulder
size rock fragments and little to no fmes
-Numerous 2 footH- rock fragments
-Occasional 3 foot-H rock fragments
TRENCH TERMINATED AT 5 FEET
PRACTICAL REFUSAL DUE TO OVERSIZE
ROCK
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SAMPLE SYMBOLS ° - UNSUCCESSFUL
^ ... DISTURBED OR BAG SAMPLE
c. . STANDARD PENETRATION TEST DRIVE SAMPLE (UNDISTURBED)
. CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATIDN AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECT NO. 05870-32-05
m
m
DEPTH
IN
FEET
SAHPLE
NQ.
>• CD O -I o X I-H
SOIL
CLASS
(USCS)
TRENCH T 5
ELEV. (MSL.) 376
EQUIPMENT
DATE COMPLETED 9/1/00
JD 555 TRACKHOE LU Hg
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- 2 -
- 4 -
- 6
10
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MATERIAL DESCRIPTION
UNDOCUMENTED FILL
Loose, dry, Silty, fine to coarse SAND from 0-6
inches_ _
Clast supported widi gravel, cobble and boulder
size rock fragments and little to no fines
-Numerous 2 foot+ rock fragments wilh maximum
rock size of 4 feet
-Very difficult to excavate due to large rock
TRENCH TERMINATED AT 10 FEET
PRACTICAL REFUSAL DUE TO OVERSIZE
ROCK
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SAMPLE SYMBOLS ° ••• UNSUCCESSFUL
^ ... DISTURBED OR BAG SAMPLE
C.
H..
. STANDARD PENETRATION TEST DRIVE SAMPLE (UNDISTURBED)
. CHUNK SAHPLE I ... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
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PROJECT NO. 05870-32-05
DEPTH
IN
FEET
SAMPLE
NO.
>• CD O _I O X
h-
SOIL
CLASS
(USCS)
TRENCH T 6
ELEV. (MSL.) 350
EQUIPMENT •
DATE COMPLETED 9/5/00
JD 555 TRACKHOE
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+ +
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MATERIAL DESCRIPTION
ALLUVIUM
Loose, dry to damp, dark brown. Clayey, fine to
coarse SAND with abundant gravel
-Abundant gravel lo 3 foot size fragments
-Matrix supported
-Abundant boulders al surface throughout drainage
ESCONDIDO CREEK
GRANODIORTTE/SANTIAGO PEAK
VOLCANICS (UNDIFFERENTIATED)
Slightly weathered, orange-brown, strong
GRANITIC ROCK
TRENCH TERMINATED AT 5 FEET
Figure A-6, Log of Trench T 6 UCOMI
m SAMPLE SYMBOLS • SAMPLING UNSUCCESSFUL E ... STANDARD PENETRATION TEST 1 . .. DRIVE SAHPLE (UNDISTURBED)
te ^ ... DISTURBED OR BAG SAHPLE B ... CHUNK SAMPLE 7 . .. WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
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PROJECT NO. 05870-32-05
- 0
- 2
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DEPTH
IN
FEET
SAMPLE
NO.
tr >-hi CD t-O <r _I 3 o C X 1-z H o -J tr CD
+ -f-
SOIL
CLASS
CUSCS)
;M/SM
TRENCH T 7
ELEV. (MSL.) 351
EQUIPMENT
_DATE COMPLETED
JD 555 TRACKHOE
9/5/00
MATERIAL DESCRIPTION
ALLUVIUM
Loose, damp, yellow-brown, Silty, fine to coarse,
Sandy GRAVEL with Silty SAND zones
-Abundant boulders up to 4 feet long in drainage
ESCONDIDO CREEK
GRANODIORTTE/SANTIAGO PEAK
(UNDIFFERENTIATED)
Slightly weathered to fresh, yellow-brown, strong
to very strong GRANITIC ROCK
UJ
IN
H^
u Itn
TRENCH TERMINATED AT 2 FEET
REFUSAL
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tr-o
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SAMPLE SYMBOLS ° ""' UNSUCCESSFUL
DISTURBED OR BAG SAMPLE
E.. . STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED)
. CHUNK SAHPLE I... WATER TABLE OR SEEPAGE
NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
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PROJECT NO. 05870-32-05
DEPTH
IN
FEET
SAMPLE
NO.
cr >-UJ CD 1-O <c _l o a X z 1-H O _l Q: CD
SOIL
CLASS
(USCS)
TRENCH T 8
ELEV. (MSL.) 351
EQUIPMENT
_DATE COMPLETED
JD 555 TRACKHOE
9/5/00
;UJ'
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SC/GC
MATERIAL DESCRIPTION
ALLUVIUM
Loose, moist, dark brown. Clayey SAND and
GRAVEL
-Abundant 2-3 fooH- boulders at surface
throughout drainage. Maximum size approximately
4 feet
ESCONDIDO CREEK
GRANODIORTTE/SANTIAGO PEAK
VOLCANICS (UNDIFFERENTIATED)
Slightiy weathered, yellow-brown, moderately
strong GRANITIC ROCK
TRENCH TERMINATED AT 3 FEET
k Figure A-8, Log of Trench T 8 UCOMI
p SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL E... STANDARD PENETRATION TEST 1. . DRIVE SAMPLE (UNDISTURBED)
te ^ ... DISTURBED OR BAG SAMPLE E ... CHUNK SAMPLE I . . WATER TABLE OR SEEPAGE
.juujLJiM nui. uuHL-jiiu«o onuwm nci^cun HrrLiLa UNLI fti int bh-tCll-lU BOXING OR TRENCH LOCATION AND AT THE
DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
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^ APPENDIX C
RECOMMENDED GRADING SPECIFICATIONS
FOR
RANCHO SANTA FE ROAD
PROPOSED WETLANDS MITIGATION AREA
p» SAN MARCOS, CALIFORNIA
PROJECT NO, 05870-32-22
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RECOMMENDED GRADING SPECIFICATIONS
1. GENERAL
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1^ 1.1. These Recommended Grading Specifications shall be used in conjunction with the
Geotechnical Report for the project prepared by Geocon Incorporated. The
I recommendations contained in the text of the Geotechnical Report are a part of the
earthwork and grading specifications and shall supersede the provisions contained
hereinafter in the case of conflict.
1.2. Prior to the commencement of grading, a geotechnical consultant (Consultant) shall be
employed for the purpose of observing earthwork procedures and testing the fills for
substantial conformance with the recommendations of the Geotechnical Report and these
specifications. It will be necessary that the Consultant provide adequate testing and
observation services so that he may determine that, in his opinion, the work was performed
in substantial conformance with these specifications. It shall be the responsibility of the
Contractor to assist the Consultant and keep him apprised of work schedules and changes
so that personnel may be scheduled accordingly.
1.3. It shall be the sole responsibility of the Contractor to provide adequate equipment and
methods to accomplish the work in accordance with appHcable grading codes or agency
ordinances, these specifications and the approved grading plans. If, in the opinion of the
Consultant, unsatisfactory conditions such as questionable soil materials, poor moisture
p condition, inadequate compaction, adverse weather, and so forth, result in a quality of work
k not in confonnance with these specifications, the Consultant will be empowered to reject
E the work and recommend to the Owner that construction be stopped until the unacceptable
conditions are corrected.
2. DEFINITIONS
E 2.1. Owner shall refer to the owner of the property or the entity on whose behalf the grading
work is being performed and who has contracted with the Contractor to have grading
performed. ^,
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2.2. Contractor shall refer to the Contractor performing the site grading work.
2.3. Civil Engineer or Engineer of Work shall refer to the Califomia licensed Civil Engineer
or consulting firm responsible for preparation of the grading plans, surveying and verifying
as-graded topography.
GI rev. 07/02
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2.4. Consultant shall refer to the soil engineering and engineering geology consulting firm
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2.5. Soil Engineer shall refer to a Califomia licensed Civil Engineer retained by the Owner,
In who is experienced in the practice of geotechnical engineering. The Soil Engineer shall be
responsible for having qualified representatives on-site to observe and test the Contractor's
work for conformance with these specifications.
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2.6. Engineering Geologist shall refer to a Califoraia Hcensed Engineering Geologist retained
by the Owner to provide geologic observations and recommendations during the site
grading.
2.7. Geotechnical Report shall refer to a soil report (including all addenda) which may include
a geologic reconnaissance or geologic investigation that was prepared specifically for the
development of the project for which these Recommended Grading Specifications are
intended to apply.
3. MATERIALS
3.1. Materials for compacted fill shall consist of any soil excavated from the cut areas or
imported to the site that, in the opinion of the Consultant, is suitable for use in construction
of fills. In general, fill materials can be classified as soil fills, soil-rock fills or rock fills, as
defined below.
3.1.1. Soil fills are defined as fills containing no rocks or hard lumps greater than 12
inches in maximum dimension and containing at least 40 percent by weight of
material smaller than 3/4 inch in size.
3.1.2. Soil-rock fills are defined as fills containing no rocks or hard lumps larger than 4
feet in maximum dimension and containing a sufficient matrix of soil fill to aHow
for proper compaction of soil fill around the rock fragments or hard lumps as
specified in Paragraph 6.2. Oversize rock is defined as material greater than 12
inches.
3.1.3. Rock fills are defined as fills containing no rocks or hard lumps larger than 3 feet
in maximum dimension and containing little or no fines. Fines are defmed as
material smaller than 3/4 inch in maximum dimension. The quantity of fines shall
be less than approximately 20 percent of the rock fiH quantity.
GI rev. 07/02
c 3.2. Material of a perishable, spongy, or otherwise unsuitable nature as determined by the
Consultant shall not be used in fills.
3.3. Materials used for fill, either imported or on-site, shall not contain hazardous materials as
y defmed by the Califomia Code of Regulafions, Title 22, Division 4, Chapter 30, Articles 9
and 10; 40CFR; and any other applicable local, state or federal laws. The Consultant shall
P not be responsible for the identification or analysis of the potential presence of hazardous
te materials. However, if observations, odors or soil discoloration cause Consultant to suspect
the presence of hazardous materials, the Consultant may request from the Owner the
^ terminafion of grading operations within the affected area. Prior to resuming grading
operations, the Owner shall provide a written report to the Consultant indicating that the
* suspected materials are not hazardous as defined by applicable laws and regulafions.
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p 3.4. The outer 15 feet of soil-rock fill slopes, measured horizontaHy, should be composed of
in properiy compacted soil fill materials approved by the Consultant. Rock fill may extend to
the slope face, provided that the slope is not steeper than 2:1 (horizontahvertical) and a soil
layer no thicker than 12 inches is track-walked onto the face for landscaping purposes. This
procedure may be ufiHzed, provided it is acceptable to the governing agency. Owner and
Consultant.
3.5. Representafive samples of soil materials to be used for fill shall be tested in the laboratory
by the Consultant to determine the maximum density, optimum moisture content, and,
where appropriate, shear strength, expansion, and gradation characterisfics of the soil.
3.6. During grading, soil or groundwater condifions other than those idenfified in the
Geotechnical Report may be encountered by the Contractor. The Consultant shall be
notified immediately to evaluate the significance ofthe unanticipated condition
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4. CLEARING AND PREPARING AREAS TO BE FILLED
4.1. Areas to be excavated and filled shall be cleared and gmbbed. Clearing shall consist of
complete removal above the ground surface of trees, stumps, bmsh, vegetation, man-made
structures, and similar debris. Grubbing shall Consist of removal of stumps, roots, buried
logs and other unsuitable material and shah be performed in areas to be graded. Roots and
other projecfions exceeding 1-1/2 inches in diameter shall be removed to a depth of 3 feet
below the surface of the ground. Borrow areas shall be grubbed to the extent necessary to
provide suitable fill materials.
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GI rev. 07/02
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4.2. Any asphalt pavement material removed during clearing operations should be properly
disposed at an approved off-site facility. Concrete fragments which are free of reinforcing
steel may be placed in fills, provided they are placed in accordance with Secfion 6.2 or 6.3
of this document.
4.3. After clearing and grubbing of organic matter or other unsuitable material, loose or porous
soils shall be removed to the depth recommended in the Geotechnical Report. The depth of
removal and compaction shall be observed and approved by a representafive of the
Consultant. The exposed surface shall then be plowed or scarified to a minimum depth of 6
inches and unfil the surface is free from uneven features that would tend to prevent uniform
compaction by the equipment to be used.
4.4. Where the slope rafio of the original ground is steeper than 6:1 (horizontahvertical), or
where recommended by the Consultant, the original ground should be benched in
accordance with the following illustration.
TYPICAL BENCHING DETAIL
Finish Grade Original Ground
Remove All
Unsuitable Material
As Recommended By
Soil Engineer
Finish Slope Surface
Slope To Be Such That
Sloughing Or Sliding
Does Not Occur
See Note 1 See Note 2'
No Scale
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DETAIL NOTES; (1) Key width "B" should be a minimum of 10 feet wide, or sufficiently wide to
permit complete coverage with the compaction equipment used. The base of the
key should be graded horizontal, or inclined slightly into the natural slope.
(2) The outside of the botlom key should be below the topsoil or unsuitable surficial
material and at least 2 feet into dense formational material. Where hard rock is
exposed in the bottom of the key, the depth and configuration of the key may be
modified as approved by the Consultant.
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GI rev. 07/02
4.5. After areas to receive fill have been cleared, plowed or scarified, the surface should be
^ disced or bladed by the Contractor unfil it is uniform and free from large clods. The area
^ should then be moisture conditioned to achieve the proper moisture content, and compacted
^ as recommended in Secfion 6.0 of these specifications.
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^ 5. COMPACTION EOUIPMENT
5.1. Compaction of soil or soil-rock fill shall be accomplished by sheepsfoot or segmented-steel
0m wheeled rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of
acceptable compacfion equipment. Equipment shall be of such a design that it will be
capable of compacting the soil or soil-rock fiU to the specified relafive compacfion at the
specified moisture content.
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m 5.2. Compaction of rock fills shaH be performed in accordance with Secfion 6.3.
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6. PLACING, SPREADING AND COMPACTION OF FILL MATERIAL
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6.1. Soil fill, as defmed in Paragraph 3.1.1, shall be placed by the Contractor in accordance with
^ the following recommendations:
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^ 6.1.1. Soil fill shall be placed by the Contractor in layers that, when compacted, should
te generally not exceed 8 inches. Each layer shall be spread evenly and shall be
thoroughly mixed during spreading to obtain uniformity of material and moisture
^ in each layer. The entire fill shall be constmcted as a unit in nearly level lifts. Rock
materials greater than 12 inches in maximum dimension shall be placed in
^ accordance with Section 6.2 or 6.3 of these specificafions.
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p. 6.1.2. In general, the soil fill shall be compacted at a moisture content at or above the
^ optimum moisture content as determined by ASTM D1557-00.
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6.1.3. When the moisture content of soil fill is below that specified by the Consultant,
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water shaH be added by the Contractor untH the moisture conteni is in the range
m specified.
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6.1.4. When the moisture content of the soil fill is above the range specified by the
^ Consultant or too wet to achieve proper compaction, the soil fill shaH be aerated by
the Contractor by blading/mixing, or other safisfactory methods unfil the moisture
P content is within the range specified,
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GI rev. 07/02
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6.1.5. After each layer has been placed, mixed, and spread evenly, it shaH be thoroughly
P compacted by the Contractor to a relative compacfion of at least 90 percent, te
• Relative compacfion is defined as the rafio (expressed in percent) of the in-place
dry density of the compacted fill to the maximum laboratory dry density as
^ determined in accordance with ASTM D1557-00. Compacfion shaH be continuous
over the enfire area, and compacfion equipment shall make sufficient passes so that
^ the specified minimum relafive compacfion has been achieved throughout the te
entire fiH.
te 6.1.6. Soils having an Expansion Index of greater than 50 may be used in fills if placed at
least 3 feet below fmish pad grade and should be compacted at a moisture content
p^
^ generally 2 to 4 percent greater than the optimum moisture content for the material.
^ 6.1.7. Properly compacted soil fill shall extend to the design surface of fill slopes. To
"I" achieve proper compaction, it is reconunended that fill slopes be over-built by at
^ least 3 feet and then cut to the design grade. This procedure is considered
^ preferable to track-walking of slopes, as described in the following paragraph.
^ 6.1.8. As an altemafive to over-building of slopes, slope faces may be back-rolled with a
^ heavy-duty loaded sheepsfoot or vibratory roller at maximum 4-foot fill height
<p» intervals. Upon complefion, slopes should then be track-walked with a D-8 dozer
\im or similar equipment, such that a dozer track covers all slope surfaces at least
twice.
6.2. Soil-rock fill, as defmed in Paragraph 3.1.2, shall be placed by the Contractor in accordance
^ with the following recommendafions:
^ 6.2.1. Rocks larger than 12 inches but less than 4 feet in maximum dimension may be
^ incorporated into the compacted soil fill, but shall be limited to the area measured
15 feet minimum horizontally from the slope face and 5 feet below finish grade or
3 feet below the deepest utility, whichever is deeper. m
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6.2.2. Rocks or rock fragments up to 4 feet in maximum dimension may either be
individually placed or placed in windrows. Under certain conditions, rocks or rock
fragments up to 10 feet in maximum dimension may be placed using similar
methods. The acceptability of placing rock materials greater than 4 feet in
maximum dimension shall be evaluated during grading as specific cases arise and
p shaH be approved by the Consultant prior to placement.
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6.2.3. For individual placement, sufficient space shall be provided between rocks to allow
for passage of compaction equipment.
pft 6.2.4. For windrow placement, the rocks should be placed in trenches excavated in
li properly compacted soil fill. Trenches should be approximately 5 feet wide and 4
feet deep in maximum dimension. The voids around and beneath rocks should be
filled with approved granular soil having a Sand Equivalent of 30 or greater and
should be compacted by flooding. Windrows may also be placed ufilizing an
)p "open-face" method in Heu of the trench procedure, however, this method should
te first be approved by the Consultant.
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6.2.5. Windrows should generally be parallel to each other and may be placed either
parallel to or perpendicular to the face of the slope depending on the site geometry.
The minimum horizontal spacing for windrows shall be 12 feet center-to-center
with a 5-foot stagger or offset from lower courses to next overiying course. The
minimum verfical spacing between windrow courses shaH be 2 feet from the top of
|g a lower windrow to the bottom of the next higher windrow.
^ 6.2.6. All rock placement, fill placement and flooding of approved granular soil in the te
windrows must be continuously observed by the Consultant or his representafive.
9im
^ 6.3. Rock fills, as defined in Section 3.1.3., shall be placed by the Contractor in accordance with
the following recommendations:
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6.3.1. The base of the rock fiH shall be placed on a sloping surface (minimum slope of 2
^ percent, maximum slope of 5 percent). The surface shall slope toward suitable
^ subdrainage oufiet facilifies. The rock fills shall be provided with subdrains during
p. construction so that a hydrostatic pressure buildup does not develop. The subdrains
^ shall be permanenfiy connected to controlled drainage facilifies to control post-
construction infiltration of water.
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6.3.2. Rock fills shall be placed in lifts not exceeding 3 feet. Placement shall be by rock
mm tmcks traversing previously placed lifts and dumping at the edge of the currently
IH placed lift. Spreading of the rock fill shall be by dozer to facilitate seating of the
rock. The rock fiH shall be watered heavily during placement. Watering shall
consist of water tmcks traversing in front of the current rock lift face and spraying
water continuously during rock placement. Compacfion equipment with
i*t compactive energy comparable to or greater than that of a 20-ton steel vibratory
ku roller or other compacfion equipment providing suitable energy to achieve the
required compacfion or deflection as recommended in Paragraph 6.3.3 shaH be
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GI rev. 07/02
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utilized. The number of passes to be made will be determined as described in
Paragraph 6.3.3. Once a rock fill lift has been covered with soil fill, no additional
rock fill lifts will be permitted over the soil fill.
ll 6.3.3. Plate bearing tests, in accordance with ASTM Dl 196-93, may be performed in
both the compacted soil fill and in the rock fill to aid in determining the number of
2 passes of the compaction equipment to be performed. If performed, a minimum of
three plate bearing tests shaH be performed in the properly compacted soil fill
C (minimum relative compacfion of 90 percent). Plate bearing tests shall then be
performed on areas of rock fill having two passes, four passes and six passes of the
compaction equipment, respecfively. The number of passes required for the rock
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fill shall be determined by comparing the results of the plate bearing tests for the
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soil fill and the rock fill and by evaluating the deflection variation with number of
!• passes. The required number of passes of the compaction equipment will be
te performed as necessary unfil the plate bearing deflections are equal to or less than
that determined for the properly compacted soil fill. In no case will the required
1^ number of passes be less than two.
6.3,4. A representative of the Consultant shall be present during rock fill operafions to
k verify that the minimum number of "passes" have been obtained, that water is
being properly applied and that specified procedures are being followed. The actual
1^ number of plate bearing tests will be determined by the Consultant during grading.
In general, at least one test should be performed for each approximately 5,000 to
te 10,000 cubic yards of rock flll placed.
DM 6.3.5. Test pits shall be excavated by the Contractor so that the Consultant can state that,
^ in his opinion, sufficient water is present and that voids between large rocks are
properly filled with smaller rock material. In-place density testing will not be
required in the rock fills.
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6.3.6. To reduce the potential for "piping" of fines into the rock fill from overlying soil
te fill material, a 2-foot layer of paded filter material shall be placed above the
^ uppermost Hft of rock fill. The need to place graded filter material below the rock
^ should be determined by the Consultant prior to commencing grading. The
gradation of the graded filter material will be determined at the fime the rock fill is
P being excavated. Materials typical of the rock fill should be submitted to the
^ Consultant in a fimely manner, to allow design of the graded filter prior to the
^ commencement of rock fill placement.
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GI rev. 07/02
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6.3.7. All rock fill placement shall be continuously observed during placement by
representatives of the Consultant.
7. OBSERVATION AND TESTING
7.1. The Consultant shall be the Owners representative to observe and perform tests during
clearing, grubbing, and filling and compaction operations. In general, no more than 2 feet
in vertical elevation of soil or soil-rock fill shall be placed without at least one field density
test being performed within that interval. In addifion, a minimum of one field density test
shall be performed for every 2,000 cubic yards of ^0/7 or soil-rock fill placed and
compacted.
7.2. The Consultant shall perform random field density tests of the compacted soil or soil-rock
fill to provide a basis for expressing an opinion as to whether the fill material is compacted
as specified. Density tests shall be performed in the compacted materials below any
disturbed surface. When these tests indicate that the density of any layer of fill or portion
P thereof is below that specified, the particular layer or areas represented by the test shall be
* reworked until the specified density has been achieved.
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te 7.3. During placement of rock fill, the Consultant shall verify that the minimum number of
passes have been obtained per the criteria discussed in Section 6.3.3. The Consultant shall
request the excavation of observation pits and may perform plate bearing tests on the
placed rock fills. The observafion pits will be excavated to provide a basis for expressing
i" an opinion as to whether the rock fill is properly seated and sufficient moisture has been
te applied to the material. If performed, plate bearing tests will be performed randomly on the
surface of the most-recenfiy placed lift. Plate bearing tests will be performed to provide a
basis for expressing an opinion as to whether the rock fill is adequately seated. The
maximum deflection in the rock fill determined in Section 6.3.3 shall be less than the
maximum deflection of the properiy compacted soil fill. When any of the above criteria
indicate that a layer of rock fill or any portion thereof is below that specified, the affected
^ layer or area shall be reworked unfil the rock fill has been adequately seated and sufficient
moisture applied.
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7.4. A settlement monitoring program designed by the Consultant may be conducted in areas of
rock fill placement. The specific design of the monitoring program shall be as
recommended in the Conclusions and Recommendafions section of the project
Geotechnical Report or in the final report of testing and observafion services performed
during grading.
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7.5. The Consultant shall observe the placement of subdrains, to verify that the drainage devices
(P have been placed and constructed in substantial conformance with project specifications.
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g 7.6. Tesfing procedures shall conform to the foHowing Standards as appropriate:
7.6.1. Soil and Soil-Rock Fills:
7.6.1.1. Field Density Test, ASTM D1556-00, Density of Soil In-Place By the
Sand-Cone Method.
7.6.1.2. Field Density Test, Nuclear Method, ASTM D2922-96, Density of Soil and
Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth).
7.6.1.3. Laboratory Compacfion Test, ASTM D1557-00, Moisture-Density
Relations of Soils and Soil-Aggregate Mixtures Using 10-Pound Hammer
and 18-Inch Drop.
7.6.1.4. Expansion Index Test, ASTM D4829-95, Expansion Index Test.
7.6.2. Rock Fills
7.6.2.1. Field Plate Bearing Test, ASTM Dl 196-93 (Reapproved 1997) Standard
Method for Nonreparative Static Plate Load Tests of Soils' and Flexible
Pavement Components, For Use in Evaluation and Design of Airport and
pp Highway Pavements.
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8. PROTECTION OF WORK
^ 8.1. During construcfion, the Contractor shall properly grade all excavated surfaces to provide
positive drainage and prevent ponding of water. Drainage of surface water shaH be
*^ controlled to avoid damage to adjoining properties or to finished work on the site. The
Contractor shall take remedial measures to prevent erosion of freshly graded areas unfil
^ such fime as permanent drainage and erosion control features have been instaHed. Areas
^ subjected to erosion or sedimentation shall be properly prepared in accordance with the
Specificafions prior to placing additional fill or structures.
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8.2. After complefion of grading as observed and tested by the Consultant, no further
pM excavafion or filling shaH be conducted except in conjuncfion with the services of the
te Consultant.
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9. CERTIFICATIONS AND FINAL REPORTS
9.1. Upon complefion of the work, Contractor shall fumish Owner a certification by the Civil
Engineer stating that the lots and/or building pads are graded to within 0.1 foot vertically of
elevafions shown on the grading plan and that aH tops and toes of slopes are within 0.5 foot
horizontally of the posifions shown on the grading plans. After installafion of a section of
subdrain, the project Civil Engineer should survey its locafion and prepare an as-built plan
of the subdrain locafion. The project Civil Engineer should verify the proper outlet for the
subdrains and the Contractor should ensure that the drain system is free of obstmctions.
9.2. The Owner is responsible for furnishing a final as-graded soil and geologic report
satisfactory to the appropriate goveraing or accepting agencies. The as-graded report
should be prepared and signed by a California licensed Civil Engineer experienced in
geotechnical engineering and by a California Certified Engineering Geologist, indicafing
that the geotechnical aspects of the grading were performed in substantial conformance
with the Specifications or approved changes to the Specificafions.
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