HomeMy WebLinkAbout95080-2; Ryan Property - Geotechnical Investigation-Pacific; Ryan Property - Geotechnical Investigation; 1995-10-13i
A dTGCh Engineering, Inc.
1 7950 Silverton Ave. Suite 116
San Diego, CA 92126
• Tel: (619) 549-0588 Fax: (619) 549-1541
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• REPORT OF GEOLOGIC AND GEOTECHNICAL
" INVESTIGATION
. FOR DEVELOPMENT OF D. RYAN PROPERTY AT
I CARLSBAD, CALIFORNIA
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PRESENTED TO
PACIFIC VIEW LTD.
I P.O. Box2198
— Carlsbad, California 92018
m (619)722-6358
1
October 16, 1995
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AdTechEngineering, Inc.
7950 Silverton Ave. Suite 116
San Diego CA 92126
Tel: (619) 549-0588 Fax: (619) 549-1541
October 16, 1995 FILE No.: 95080-2
Don Jack, Managing Member
Pacific View LTD.
P.O. Box2198
Carlsbad, CA 92018
Subject: Report of Geologic and Geotechnical Investigation for development of
D. Ryan Property at Carlsbad, California.
Dear Mr. Jack:
In accordance with your written authorization dated 10/3/95, AdTech
Engineering has performed a geotechnical investigation and soil testing for the
subject property. The purpose of the investigation is for the development of the
property. It has been divided in 24 lots and two access roads.
Plan lay-out of site was provided by R.D.G. consultants, 3042 Harding
Street, Carlsbad, CA 92006, phone: (619)729-0150, fax: (619)729-0282, dated
10/6/95.
Enclosed is the report of this work. Should you have any questions regarding
this report, please call me at your convenience.
Sincerely yours,
Ziad Bayasi, R.C.E
OCT 1 6 tr^n
* Table of Contents
-•am
** Introduction 3
** Scope 3
General Description of the Property 6
** Site Visit and Investigation Findings 6ox
General Geology of Site 6
«**Faults and Ground Shaking 7
MP
Ground Water 12
^ Description of Soil Sampling and Testing 12
Conclusions and Recommendations 13
« Grading 14
Site Preparation 14
Oversize Rocks 14
Surface Drainage 14
Earthwork 14
Foundations 15
General 15
Reinforcement 15
Slab on Grade 15
Settlement and Expansion Characteristics 16
~" Slopes 16
Retaining Walls 16
•M»
Limitations 18
•B*
Appendix 1: Sampling and Test Results
«M
Appendix 2: General Earthwork and Grading Specifications«•
Appendix 3: Homeowner's Guidelines for Slope Maintenance
AdTech Engineering, Inc.
95080
REPORT OF GEOLOGIC AND GEOTECHNICAL
INVESTIGATION
FOR DEVELOPMENT OF D. RYAN PROPERTY AT
CARLSBAD, CALIFORNIA
Introduction
This report represents the results of our geotechnical and geologic investigations
of the subject project which is located at Carlsbad Village Drive and Donna Drive
in the City of Carlsbad. Site location/vicinity map is shown in Figure 1.
At the time of this investigation, no specific development plans for the site were
available. However it is our understanding that the site will be developed to
receive residential homes consisting of one to two story structures of wood-frame
construction and associated paved roads. Shallow foundations and conventional
slab-on-grade floor systems are anticipated. Grading will include cuts and fills
with a maximum depth not exceeding twenty feet.
Scope
This investigation consists of: surface observation, subsurface exploration and
sampling, collecting and testing disturbed and undisturbed samples
representative of field conditions, analysis of findings, literature review of
available geological data about the site and report preparation.
The property was measured to locate the site of each lot and road according to
the plan provided. A total of 22 soil samples were collected for all the lots, and 5
soil samples were collected for the proposed roads to provide R curves. The
purpose of the present report is to provide soil & geologic parameters for the
grading specifications as well as design parameters for the proposed
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AdTech Engineering, Inc.
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CARLSBAD
1 »!
SEE MAP
Figure 1. Site location/vicinity map.
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95080
development. Specifically, the following tasks were performed:
• Site visit including surface and subsurface observations for the soil and
geologic conditions of the site.
• Drilling and obtaining representative samples. Borings were made via two
methods, a drilling rig and a backhoe. Minimum depth of each boring was
5 feet below proposed grade.
• Testing of soil samples in the laboratory to obtain the pertinent
engineering properties of the various soil strata that will influence the
proposed development. Such properties include friction angle, cohesion,
allowable bearing pressure, expansive characteristics and settlement
potentials.
• Review of publications about the geological formation of the site to
investigate potential geologic hazards including underground water and
earthquakes.
• Evaluation of field and laboratory data as well as literature review to
develop soil engineering criteria for the site.
• Addressing potential construction difficulties including analysis of slope
stability.
• Recommendations of the appropriate foundation system for the
anticipated type of structures as well as pavements.
AdTech Engineering, Inc.
95080
General Description of the Property
The D. Ryan property is located at Carlsbad Village Dr. and Donna Dr. in
Carlsbad, California. The property has an area of 8.5 acres, and it extends
beyond the crest of a hill. The highest point is at an approximate elevation of
288 ft at the center of the property. From the highest point, the property extends
to the eastern boundary at an elevation of 215 ft with some vegetation and a
slope of 6:1 (horizontal: vertical). From the highest point to the west at an
elevation of 240 ft approximately, the property has little vegetation to none and a
slope of 6.6:1. From that elevation to the western boundary at an elevation of
200 ft there is some vegetation. The property has been divided in 22 lots with
two access roads. At the time of visiting the site, no monuments or stakes have
been placed to limit the proposed lots.
Site Visit and Investigation Findings
The site was visited by AdTech's soils engineers on October 7,8 and 9, 1995.
The property was measured to locate the site of lots and road according to the
plan provided. A total of 22 soil samples were collected for all the lots, and 5 soil
samples were collected with a maximum spacing of 150 feet from places where
the roads are indicated in the lay-out plan. Furthermore, literature review of the
geologic formation of the site was conducted to assess the pertinent conditions
of the property.
GENERAL GEOLOGY OF SITE
According to California Division of Mines and Geology, the bedrock structure is
of the Eocene age and is coverd by Tertiary sedimentary rocks of Santiago
formation. Sedimentary rocks of Eocene age are common in the costal area
AdTech Engineering, Inc.
95080
from the northern Santa Ana Montains to the Oceanside-Del Mar costal area.
According to Kenneth Lee Wilson, Eocene and Related Geology of a Portion of
the San Luis Rey and Encinitas Quadrangles, the Santiago formation of the
Santa Ana Montains is characterized by a thin basel conglomerate that is
overlined by fine- to medium-grained, gray green or brown to buff sanstone that
contains a middle Eocene marine molluscan fauna. The surface soil at the site
appears to be a sandstone and sandy soil similar in composition to the bedrock.
Such geologic formation as the one at the site is generally considered to be
stable. The soil at the site seemed to conform with the general geologic cross
section of Oceanside-Carlsbad area. Sandy soils with tan to dark brown or red
were encountered. The property appeared to consist of a natural centered pad
with downslopes at the eastern and western portions. The eastern and western
portions of the land level off forming two other natural pads of the property.
FAULTS AND GROUND SHAKING
Figure 2 illustrates the locations of major seismic faults in Southern California.
Elsinore fault is approximately 25 miles from the site, San Jacinto fault is
approximately 45 miles from the site, Rose Canyon fault is about 10 miles from
the site and Newport-Inglewood fault is about 15 miles from the site. The
following table includes the maximum probable Richter earthquake magnitudes
for the faults mentioned above:
AdTech Engineering, Inc.
95080
Fault Zone
Elsinore
San Jacinto
Rose Canyon
Newport-
Ing Iwood
Distance
25 miles
45 miles
10 miles
15 miles
Maximum
Probable
Earthquake
7.3 magnitude
7.8 magnitude
6.0 magnitude
5.9 magnitude
Bedrock
Acceleration
0.29 g
0.18 g
0.16 g
0.15 g
Design
Acceleration
0.12 g
0.08 g
0.06 g
0.05 g
Rose Canyon and Newport-Inglewood faults are not expected to generate major
earthquakes. Most of the ground shaking at the site would be generated by
major quakes at Elsinore fault or San Jacinto fault.
Figure 3 contains the locations of semi-major faults in San Diego County. The
closest one to the site is Carmel Valley fault. There are also small faults in
Oceanside-Carlsbad area as shown in Figure 4. None of the faults mentioned
above has been active in the past twenty years. Even though this site is not
adjacent or close to an active fault, proper precaution need to be taken for
earthquake design of structures and retaining walls.
Different faults in San Diego County have different zone slip rates that vary from
very low to very high rate of activity. The following chart summarizes the
probability of quake events in the site:
Peak Acceleration
0.20 g
0.10 g
0.05 g
Design Acceleration
0.10 g
0.05 g
0.03 g
Probability of Occurrence
1X1 Q-'
1X1 Q-1
1X10'1
AdTech Engineering, Inc.
95080
Figure 2. Major seismic faults in southern California.
Carmel Valley fault
AdTech Engineering, Inc.
95080
Figure 3. Location of semi-major faults in San Diego County.
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AdTech Engineering, Inc.
9S080
CARLSBAD
SEE MAP
Figure 4. Small faults in the Oceanside-Carlsbad Area.
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•*• AdTech Engineering, Inc.
95080
$m
m Structures and retaining walls designed in accordance with the Uniform Building
Code have shown satisfactory performance in the event of a major earthquake.
«* It is therefore recommended herein that the Uniform Building Code be followed in
regard to seismic design for the site.
GROUND WATER
** No ground water or saturated soil was encountered at the site in any of the
*"" borings. We do not anticipate any major ground water problems during or after
construction.
** DESCRIPTION OF SOIL SAMPLING AND TESTING
Appendix 1 shows the location of borings taken from the site for studying the soil
conditions for the proposed structures. A total of 22 samples were taken. Two
^ types of samples were obtained: undisturbed and disturbed. Representative
samples were selected for testing of the engineering properties. Some of the
^ borings for disturbed soil samples were made with a backhoe to a depth between
^ three to thirteen feet from the surface procuring to be at least five feet below the
.„.- proposed finished grade. The undisturbed samples were taken from borings
drilled with a drill rig. Depths of these samples ranged between two to twenty
— three feet from the surface. The field observations are as follows:
** • The organic top soil extend to a depth of 4" in bare ground areas (lots 9,
— 10, 11 and 12). And it extends up to 8" in vegetated areas (rest of land).
*** • The soil samples from all lots were classified in the laboratory according to
"• the Unified Soil Classification System (ASTM D 2487).
*** • Expansion potential was evaluated and determined to be very low due to
*" the sandy nature of the soil (expansion index less than 10%).
MM
• The soil appeared to be wetter in the lots where vegetation was present.
• The bedrock at the highest spot (288 ft.) was found at a depth of 14 ft. All
the soil up to this depth was a very firm sandstone of the Eocene age. It is
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AdTech Engineering, Inc.
95080
not anticipated that the lots requiring cuts would be at a pad elevation
lower than the elevation of the bedrock.
Compacted specimens from lots that require cut was evaluated for
adequacy as a fill material. ASTM standard D-1557 (modified Proctor
test) was followed to measure the optimum moisture content and
maximum dry density. Imported fill must evaluated by AdTech
Engineering prior to utilization at the site.
Laboratory tests were conducted on soil specimens of this site to
determine if the internal angle of friction, cohesion, unit weight, moisture
content and classification of undisturbed soil sample at this depth as well
as a compacted specimen from a disturbed sample. Sample elevation
and location were selected to represent the subgrade (5 feet below pad
elevation) for each lot. The above mentioned engineering properties were
evaluated for the fill soil as well.
It was found that soil under most of the lots up to a depth of 5 to 15 feet
from the surface consists of sandy soil that can be used for fill after cutting
the highest lots and removing the top soil in the lowest lots.
In lots 14 and 15, a soil strip of gray sand of approximately 40 feet width is
present. This gray sand is relatively inferior to the sandy soil in the rest of
the land due to its coarse texture and complete lack of cohesion. It
appeared to be of marine deposits. It is recommended that the top 5 feet
of said white sand strip be removed and replaced with fill complying with
the fill requirements of this report.
Conclusions and Recommendations
No geological or geotechnical conditions were encountered that could preclude
the proposed development at the site being studied in this report. Detailed
recommendations pertaining to soil conditions are as follows.
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AdTech Engineering, Inc.
95080
GRADING
«•• Site Preparation
1. Site preparation should commence with removal of any vegetation,
** deleterious materials and top soil.
2. For pads located partially or complete in cut, overexcavation and/or
*** deepening the footings will be required for cut/fill transitions crated by precise
grading. The overexcavated areas should extend a minimum of five feet beyond
*** the building footprint.
"*" 3. Fill caps should be overexcavated such that a minimum of three foot fill cap
s*»
is crated on the entire pad.
4. To a depth of 12 inches underneath the proposed road locations must«•
scarified and recompacted to 90% maximum density in accordance with ASTM
D-1557.
•**-'
39ft
Oversize Rocks
Oversize rocks greater than 3 feet in maximum dimension must be exported from
^ the site. Rocks up to 3 feet in maximum dimension may be included in the
grading (fill) operation provided that the detail included within this report be
«•» followed. Oversize rocks will hamper fill and compaction operations.
»* Surface Drainage
- It is recommended that all surface drainage be directed away from the proposed
"" structures at the top of the slopes. Water pounding is not permitted adjacent to
foundation.
4MU-
Earthwork
Earthwork and grading operations must follow the recommendations of this
report. All special site preparation recommendations included herein shall
«Mt
supersede the general guidelines for grading and fill attached to this report. Fill
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bases must be benched. Fills must be compacted to 90% maximum density and
angle of internal friction of 35° at least. All embankments and/or fills including
utility trenches within 5 feet of the proposed structures and beneath pavements
must be compacted to at least 90% of maximum density. Top 12 inch of soil
beneath paved areas (below the subbase) must be compacted to 95% relative
compaction. It is recommended that at least 6 inches of crushed rock base be
used for the asphalt pavement at the site.
FOUNDATIONS
General
Shallow foundations may be used to support the proposed structures. Footings
must be at least 18 inches below lowest adjacent finished grade. Minimum width
of 12 inches and 18 inches are recommended for continuous and isolated
footings, respectively. Bearing capacities of 2,500 psf and 1,800 psf are
recommended for footings on cut and fill, respectively. 33% increase of bearing
capacity is allowed for wind and/or seismic loads.
Reinforcement
Footings must be reinforced with two #4 bars positioned near the bottom of the
footing (3.5 inch clear cover) and two #4 bars near the top of the footing. This
reinforcement is based upon soil characteristics and does not replace structural
reinforcement for the footing.
Slab on Grade
Concrete slabs on grade for this project must be 5.5 inches minimum thickness,
with 2,500 psi minimum compressive strength, reinforced with #4 bars at 18
inches o/c. Slabs on grade must be underlain by 4 inches of poorly graded
coarse sand or crushed rock. Slabs on grade underneath moisture sensitive
floor covering must be underlain (from bottom to top) with 4 inch poorly graded
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AdTech Engineering, Inc.
95080
coarse sand or crushed rock, visqueen barrier and 2 inch clean sand for proper
concrete curing.
Settlement and Expansion Characteristics
The anticipated settlement of the proposed structures (total and/or differential) is
within the tolerable limits. Hairline cracks in stucco and concrete due to
shrinkage or minor settlement is considered normal and may be anticipated. The
soil at the site, due to its sandy nature, is predominantly nonexpansive. The
recommendations in this report reflect settlement and expansion potentials of the
soil at the site.
Slopes
Permanent slopes in cut soil are required to have a slope angle of 31° from
horizontal (1.75h:1v). Permanent slopes in fill soil are required to have a slope
angle of 27° from horizontal (2h:1v). Temporary cuts can be at 0.25h:1v.
Retaining Walls
Due to the presence of potential cuts and fills at the site, use of retaining walls is
anticipated. For design of retaining walls, the following parameters must be
followed:
Cut soil:
Angle of internal friction, § = 36°
Density, y = 130 pcf
Cohesion, c = 0 psf
Coefficient of friction between the soil and the footing, \i = 0.35
Passive pressure, p = 300 psf/ft
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AdTech Engineering, Inc.
95080
Fill soil:
Optimum moisture content = 10.5%
Angle of internal friction, <|> = 32°
Density, y = 125 pcf
Cohesion, c = 0 psf
Coefficient of friction between the soil and the footing, ja = 0.30
Passive pressure, p = 200 psf/ft
When friction and passive pressure are used simultaneously for resistance of soil
pressure, the latter must be reduced by 1/3. Retaining walls are recommended
to have 12 inches of poorly graded crushed rock backfill and filter fabric behind
the rocks. Underdrain behind retaining walls greater than 3.5 feet in height must
be provided to alleviate the effect of water accumulation behind the wall.
P,V:';'/''•-•"' " <••' ';. V, \' r.-: .:,-.•;- ",'.•;-. t-', \S
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AdTech Engineering, Inc.
95080
Limitations
The recommendations presented in this report are contingent upon our review of
final plan and specifications for the proposed structure and pavement as per
chapter 70 of the UBC. It is recommended that AdTech Engineering, Inc. be
retained to provide continuous soil engineering services during earthwork
operations to observe compliance with design concepts of this report and to
provide design changes in the event that subsurface soil conditions differ from
the anticipated conditions. The recommendations made in this report reflect
AdTech Engineering, Inc. best opinion and judgment based on the evaluation of
the subsurface soil conditions determined from the samples collected.
Unforeseen variations in unexplored and intermediate areas could affect the
performance of the foundations and cut and fill slopes. Therefore, it is important
that a representative from AdTech be present during earthwork of this project.
AdTech Engineering must be informed of any design changes that pertain to
earthwork in this project so that proper consideration be taken. As time elapses,
site conditions could change and continuous observation of these conditions by
AdTech is necessary. In the performance of this report, we followed the levels of
care and skill generally exercised by members of our profession. The borings
taken by AdTech, yet extensive, are samples and do not completely represent
the subsurface soil conditions at the site. AdTech Engineering will be
responsible for any changes of site conditions at the locations of the borings
taken from the site and will not be responsible for interpolation of said site
conditions outside the location of the borings. It is the responsibility of Pacific
View Ltd. or their representative to ensure that the recommendations of this
report are followed.
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• Appendix 1:
| Sampling and Test Results
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95080
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LOG OF BORINGS
AdTech Engineering, Inc.
95080
LOT No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
EXISTING
GRADE
(ft)
205 to 248
200 to 230
200 to 228
207 to 225
21 2 to 228
214 to 228
205 to 226
205 to 235
239 to 262
240 to 261
255 to 270
275 to 288
254 to 287
239 to 270
247 to 260
232 to 258
227 to 239
210 to 225
225 to 260
238 to 260
235 to 260
247 to 265
260 to 280
260 to 285
PAD
ELEVATION
(ft)
250
247
243
239
236
229
223
223
243
256
263
267
263
256.5
248.5
241.5
236
237
237
241
248
256
262.5
267.5
BORING
1
1
2
3
4
5
5
6
7
8
9
10
11
11
12
13
14
15
16
17
18
18
18
19
20
21
11
22
11
11
BORING DEPTH FROM
EXISTING GRADE
(ft)
3
3
5
3
3
5
5
5
5
5
5
5
25
25
3
13
20
3
5
5
3
3
3
5
5
5
25
5
25
25
SOIL DESCRIPTION
Fill 2 to 30 ft
Fill 10 to 32 ft
Fill 3 to 26 ft
Fill 14 to 24 ft
Fill11 to 20 ft
CutO to 1ft& Fill Oto 10ft
Cut 0 to 1 ft & Fill 0 to 4 ft
Cut 0 to 7 ft & Fill 0 to 3 ft
Cut 0 to 12 ft & Fill Oto 4 ft
Cut 0 to 4 ft & Fill Oto 10 ft
Cut 0 to 7 ft & Fill 0 to 8 ft
Cut 8 to 21 ft
Cut 0 to 25 ft & Fill 0 to 9 ft
Cut 0 to 1 2.5 ft & Fill Oto 7.5 ft
Cut 0 to 11.5 ft & Fill Oto 3.5 ft
Cut 0 to 13 ft & Fill Oto 3 ft
Fill 0 to 14 ft
Fill 8 ft to 16 ft
Fill Oto 10 ft
Cut 0 to 12 ft & Fill Oto 8 ft
Cut 0 to 5 ft & Fill 0 to 7 ft
Cut 0 to 12 ft & Fill Oto 4 ft
Cut 7 to 18 ft
Cut Oto 18 ft
Sample Kind:
US: Undisturbed, driven tube sample
CK: Undisturbed chunk sample
BG: Bulk sample
SP: Standard penetration sample
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1 i i t 4 i i I i 1 I-i I i i i I i
Locations of Borings for Foundation Soil Testing
AdTech Engineering, Inc.
95080
Project: D. Ryan
Job No.: 95080
BORING LOG
Boring No.: 1
Method of Boring: Drill Rig Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
US
Soil
Classification
SP
Soil Description
Top Soil
Firm brown silty sand
Boring terminated at 3 ft
Moisture
(%)
5
Unit Weight
(pcf)
112
Dry Density
(pcf)
108
••
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AdTech Engineering, Inc.
95080
Project: D. Ryan
Job No.: 95080
BORING LOG
Boring No.: 2
Method of Boring: Drill Rig Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
US
Soil
Classification
SP
Soil Description
Top Soil
Firm dry dark brown silty sand
Boring terminated at 5 ft
Moisture
(%)
2.9
Unit Weight
(pcf)
108
Dry Density
(pcf)
105
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AdTech Engineering, Inc.
95080
Project:
Job No.
D. Ryan
95080
BORING LOG
Boring No.: 3
Method of Boring: Backhoe Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Medium firm brown silty sand
Boring terminated at 3 ft
Moisture
(%)
4.5
Unit Weight
(pcf)
111
Dry Density
(pcf)
108
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AdTech Engineering, Inc.
95080
Project:
Job No.
D. Ryan
:95080
BORING LOG
Boring No.: 4
Method of Boring: Backhoe Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Medium firm brown silty sand
Boring terminated at 3 ft
Moisture
(%)
5.5
Unit Weight
(pcf)
114
Dry Density
(pcf)
110
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AdTech Engineering, Inc.
95080
Project:
Job No.:
D. Ryan
95080
BORING LOG
Boring No.: 5
Method of Boring: Drill Rig Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
US
Soil
Classification
SP
Soil Description
Top Soil
Firm dry dark brown silty sand
Boring terminated at 5 ft
Moisture
(%)
1.8
Unit Weight
(pcf)
111
Dry Density
(pcf)
109
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AdTech Engineering, Inc.
95080
Project: D. Ryan
Job No.: 95080
BORING LOG
Boring No.: 6
Method of Boring: Drill Rig Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
US
Soil
Classification
SP
Soil Description
Top Soil
Firm dry dark brown silty sand
Boring terminated at 5 ft
Moisture
(%)
2
Unit Weight
(pcf)
114
Dry Density
(pcf)
112
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AdTech Engineering, Inc.
95080
Project:
Job No.:
D. Ryan
:95080
BORING LOG
Boring No.: 7
Method of Boring: Backhoe Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Firm dry dark brown silly sand
Boring terminated at 5 ft
Moisture
(%)
2.2
Unit Weight
(pcf)
112
Dry Density
(pcf)
109
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AdTech Engineering, Inc.
95080
Project: D. Ryan
Job No.: 95080
BORING LOG
Boring No.: 8
Method of Boring: Backhoe Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Firm dry reddish brown to dark brown
silty sand
Boring terminated at 5 ft
Moisture
(%)
1.9
Unit Weight
(PCf)
110
Dry Density
(pcf)
107
29
AdTech Engineering, Inc.
95080
Project:
Job No.:
D. Ryan
:95080
BORING LOG
Boring No.: 9
Method of Boring: Backhoe Date of Boring: 10/7/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Firm dry dark brown silly sand
Boring terminated at 5 ft
Moisture
(%)
2.5
Unit Weight
(DCf)
112
Dry Density
(PCf)
109
30
AdTech Engineering, Inc.
95080
Project:
Job No.
D.Ryan
:95080
BORING LOG
Boring No.: 10
Method of Boring: Backhoe Date of Boring: 10/8/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Firm dry reddish brown silty sand
Boring terminated at 5 ft
Moisture
(%)
4.2
Unit Weight
(pcf)
113
Dry Density
(pcf)
108
31
AdTech Engineering, Inc.
95080
Project: D. Ryan
Job No.: 95080
BORING LOG
Boring No.: 11
Method of Boring: Drill Rig Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
US
US
US
US
US
Soil
Classification
SP
SP
SP
SP
SP
Soil Description
Top Soil
Firm moist tan silty sand
Finn moist tan silty sand
Very firm tan silty sand
Very trim tan silty sand
Very frim tan silty sand
Boring terminated at 25 ft
Moisture
(%)
8.4
8.8
8.5
9
10
Unit Weight
(pcf)
113
122
120
121
125
Dry Density
(pcf)
104
111
111
111
112
32
AdTech Engineering, Inc.
95080
Project:
Job No.:
D. Ryan
95080
BORING LOG
Boring No.: 12
Method of Boring: Backhoe Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Medium firm reddish brown to gray silty sand
Boring terminated at 3 ft
Moisture
(%)
4.1
Unit Weight
(pcf)
112
Dry Density
(pcf)
108
33
AdTech Engineering, Inc.
95080
Project:
Job No.:
D. Ryan
95080
BORING LOG
Boring No.: 13
Method of Boring: Backhoe Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
CK&BG
Soil
Classification
SP
SP
Soil Description
Top Soil
Soft gray silty sand
Medium firm gray silty sand
Firm gray silty sand
Boring terminated at 13 ft
Moisture
(%)
3.5
5
12.5
Unit Weight
(pcf)
120
122
Dry Density
(pcf)
114
108
34
AdTech Engineering, Inc.
95080
Project: 0. Ryan
Job No.: 95080
BORING LOG
Boring No.: 14
Method of Boring: Drill Rig Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
US
US
US
US
Soil
Classification
SP
SP
SP
SP
Soil Description
Top Soil
Soft dry gray silty sand
Medium firm moist gray silty sand
Firm moist tan silty sand
Firm moist tan silty sand
Firm moist tan silty sand
Boring terminated at 20 ft
Moisture
(%)
5
8.4
6.6
7.4
8
Unit Weight
(pcf)
126
126
118
117
Dry Density
(pcf)
116
117
110
108
35
AdTech Engineering, Inc.
95080
Project:
Job No.:
D. Ryan
:95080
BORING LOG
Boring No.: 15
Method of Boring: Backhoe Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Medium firm gray silty sand
Boring terminated at 3 ft
Moisture
(%)
3.9
Unit Weight
(PCf)
121
Dry Density
(PCf)
116
36
AdTech Engineering, Inc.
95080
Project: D. Ryan
Job No.: 95080
BORING LOG
Boring No.: 16
Method of Boring: Drill Rig Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
US
Soil
Classification
SP
Soil Description
Top Soil
Medium firm wet brown silty sand
Boring terminated at 5 ft
Moisture
(%)
6.6
Unit Weight
(pcf)
117
Dry Density
(pcf)
110
37
AdTech Engineering, Inc.
95080
Project: D. Ryan
Job No.: 95080
BORING LOG
Boring No.: 17
Method of Boring: Drill Rig Date of Boring: 10/9/9S
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
US
Soil
Classification
SP
Soil Description
Top Soil
Medium firm wet brown silty sand
Boring terminated at 5 ft
Moisture
(%)
6.9
Unit Weight
(pcf)
117
Dry Density
(pcf)
109
38
AdTech Engineering, Inc.
95080
Project:
Job No.:
D. Ryan
95080
BORING LOG
Boring No.: 18
Method of Boring: Backhoe Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Medium firm brown silty sand
Boring terminated at 3 ft
Moisture
(%)
3.2
Unit Weight
(pcf)
117
Dry Density
(pcf)
112
39
AdTech Engineering, Inc.
95080
Project:
Job No.:
D. Ryan
95080
BORING LOG
Boring No.: 19
Method of Boring: Drill Rig Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Medium firm wet darkbrown silty sand
Boring terminated at 5 ft
Moisture
(%)
6
Unit Weight
(pcf)
115
Dry Density
(pcf)
108
40
AdTech Engineering, Inc.
95080
Project: D. Ryan
Job No.: 95080
BORING LOG
Boring No.: 20
Method of Boring: Drill Rig Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
US
Soil
Classification
SP
Soil Description
Top Soil
Medium firm dry brown silty sand
Boring terminated at 5 ft
Moisture
(%)
3.5
Unit Weight
(pcf)
117
Dry Density
(pcf)
113
41
AdTech Engineering, Inc.
95080
Project:
Job No.
D. Ryan
: 95080
BORING LOG
Boring No.: 21
Method of Boring: Backhoe Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Firm dry brown silty sand
Boring terminated at 5 ft
Moisture
(%)
4.3
Unit Weight
(pcf)
116
Dry Density
(pcf)
108
42
•<*•AdTech Engineering, Inc.
95080
Project:
Job No.:
D. Ryan
95080
BORING LOG
Boring No.: 22
Method of Boring: Backhoe Date of Boring: 10/9/95
Depth
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Sample
CK&BG
Soil
Classification
SP
Soil Description
Top Soil
Firm reddish to dark brown silty sand
Boring terminated at 5 ft
Moisture
(%)
5.6
Unit Weight
(pcf)
116
Dry Density
(pcf)
108
43
•*»
Direct Shear Test Results
Normal Stress
710.0
1300.0
2600.0
Shear Stress
440.0
940.0
1840.0
Summary of Direct Shear Test Results for Cut Soil
iQOO 0
1 800 0
1600 0
i«inn n
v> 1 ?nn n
**o) i nno n
s
£ flnn n
6000
400 0
2000
00
_•" ! •">-"••
* - "r-*i_-
-^^
T
* %^»
l-'.v'V'i! 'i.^-r^V^'!"*™.
•'••„,,
. •-'•__
- ;'- 3J> - ,
':"^.*4..'U
:""' ;. "
»-' .-
' --.^t -
>~*»\.J~*
t4*l« -'«: :\ '2t»"~!»»KS"^p
,.:^V
- -•-
' •
""• l«?: '
S'i^a,? *, #.
" ' ! 1
5 •«', ^S
" V£ - "— n
'•-,"
' " -'••*":">^,'-•-Jff\:'_\
^%w-^
* iv**
- - -\
>•• , •
,™:T" -.•
f^iv, iX ",,
"" > -f'f '
jpfW--
.f^'lr.
..,,.
y^
• - , -
»-^«."^", -c«
^ ,
/^
• .)' ' -
'
'
• Shear Stress
Linear (Shear Stress)
0.0 500.0 1000.0 1500.0 2000.0 2500.0 3000.0
Normal Stress
Angle of Internal Friction = 36 Degrees
Unit Weight = 130 pcf (max.)
44
Direct Shear Test Results
Normal Stress
1425.0
2850.0
5700.0
Shear Stress
1170.0
2610.0
5040.0
Summary of Direct Shear Test Results for Fill Soil
6000 0
cnnn n
4000 0 -
(0 3000 0 -
1in
2000 0 •
1000 0 -
0 0
jg , fff JV f , „
r-i-V.-,/- •
«; -*i.^
^/.i^ '-i^'
£
>^-V-,4-
-.
-
» .^Sv. .,.-
*' ii V" , I "
" , ""4- 1 j. --, '^™ 1-J:
• .;.'.-' & ft
^ , ^.,;, • >f
• it» "»•—: '-,"
, "•,:'' ••;-
.HHj^jf^i"
- "^^^
-
'is-' ' " " - *-,
..a, j-
-.; — - -
. - ,«-^..
Jr
.-' .
• •
t , ,.
* i
..v. r- - ,
'• "8*%y*?*jF
' --
,. , , -
'«*
^
*" -tf^Mfti
~ f ll"
X
i ,_ ,.- -• Shear Stress
Linear (Shear Stress)
0.0 1000.0 2000.0 3000.0 4000.0 5000.0 6000.0
Normal Stress
Angle of Internal Friction = 37 Degrees
Unit Weight = 125 pcf (max.)
45
! ! 1 I 1 I I » I I 1 i i 1 i I I I i I I 1 i I J t t t
Compaction Test Results For Native Samples From Cut Lots
I i 1 I I
Moisture Content %
9.68
11.43
13.26
11.84
Dry Density
126
126
120.4
125.4
127
126
120
10
Summary of Compaction Test Results
11 12
Moisture Content
Dry Density
Poly. (Dry Density)
13 14
o\
AdTech Engineering, Inc.
COMPACTION TEST DATASHEET
Location of Job:
Description of soil:
Test performed by:
ASTM Method:
Blows/Layer:
No. of Layers:
Wt. of Hammer:
Water Content Determination:
Carlsbad Village Dr. & Donna Dr.
Sand
MG&HH
D1557-91
25
5
Ib.
Date of test: 10/12/95
Gs= 2.65
Mold Dimensions
Diameter: 10.1 cm
Height: 11.63 cm
Volume: 933.73 cm3
Note: All weights are in grams.
Sample No.
Moisture Tray No.
Wt. of tray + wet soil
Wt. of tray + dry soil
Wt. of water
Wt. of tray
Wt. of dry soil
Water content, %
1
1
170.7
161.86
8.84
72.9
88.96
9.9
4
176.51
167.55
8.96
72.6
94.95
9.4
2
10
84.16
77.07
7.09
15.64
61.43
11.5
11
89.14
81.65
7.49
15.53
66.12
11.3
3
17
88.15
80.46
7.69
15.6
64.86
11.9
18
89.63
81.82
7.81
5.68
66.14
11.8
4
14
88.28
79.74
8.54
15.7
64.04
13.3
15
84.57
76.56
8.01
15.62
60.94
13.1
5
Density Determination:
Sample No.
Average w%
Wt.of mold + soil
Wt. of mold
Wt. of soil in mold
Wet density
Dry density
Dry density (pcf)
Saturated Density
1
9.7
2075.4
2.22
2.03
126.4
131.6
2
11.4
2097.8
2.25
2.02
125.8
126.9
3
11.8
2099.3
2.25
2.01
125.4
125.9
4
13.2
2048.2
2.19
1.94
120.9
122.4
5
0.0
0
0.00
0.00
0.0
165.4
CHART
SERIES
1
2
135 0
G- 130 n -8. loau
»'5> 1250 -
Q>•o
£" ion 0Q I^U.U
115 0 J
1100
•v
Xs
^9>*m^
^^"^^
"""K^.
9.0 10.0 11.0 12.0 13.0 14
Water content (%)
• Series 1 • Series2
47
TRANSITION LOT DETAILS
CUT-FILL LOT
NATURAL GROUND
MINI. r~i
-.COMPACTED r-F\LLr^^^^^-*c?^^je^~^^^^^^^^^-^'-.30" MIN.
OVEREXCAVATE AND RECOMPACT
UNWEATHERED BEDROCK OR /
MATERIAL APPROVED BY '
THE GEOTECHNICAL CONSULTANT
CUT LOT
NATURAL GROUND
REMOVE
UNSUITABLE
MATERIAL
51
MIN-.
'COMPACTED::
30" MIN.
AA
OVEREXCAVATE AND RECOMPACT
UNWEATHERED BEDROCK OR
MATERIAL APPROVED BY
THE GEOTECHNICAL CONSULTANT
NOTE:
Deeper overexcavation and recomoaction shall be performed 48
if determined to be necessary by the geotechnical consultant.
BENCHING DETAILS
FILL SLOPE
PROJECTED PLANEI to I moximom Irom toe
ol slope to opproved ground
NATURAL
GROUND
REMOVE
UNSUITABLE
MATERIAL
BENCH
HEIGHT
KEY tOWEST BENCHDEPTH(KEY)
-I
FILL-OVER-CUT SLOPE
REMOVE.
UNSUITABLE
MATERIAL
NATURAL
<(Cj COMPACTED .-_-_-ji-
GROUND v _, j^gRKr-^rto-"-"-''-* I
^ - -^ISJggf^LBENC J. —-" xg^%MiN>:f i i
I. I»MIN J
I LOWEST BENCH |
V Txplcol
\
BENCH
HEIGHT
•CUT
FACE
To be conjiructed prior
to fill plocemeni
CUT-OVER-FILL SLOPE
CUT FACE
To It Constructed Prior to Fill Placement
NATURAL GROUND
OVERBUILD I TRIM BACK
REMOVE UNSUITABLE ^
MATERIAL .£.-_-_•
PROJECT PLANE
I to I wxi
toe of slope to
Approved
ground
BENCH HEIGHT
2' WIN.
KEY
DEPTH
LOWEST BENCH'
(KEY)
NOTES:
LOWEST BENCH: Depth and width subject to field change
based on consultant's inspection.
SUBDRAINAGE: Back drains may be required at the
discretion of the geotechnical consultant.
49
ROCK DISPOSAL DETAIL
FINISH GRADE
SLOPE
FACE
ir_-_-_r_- COMPACTED: 10'MIN. :
^-10' MIN.
OVERSIZE-
WINDROW.'
GRANULAR SOIL'.
To fill voids,
densified by
flooding
PROFILE ALONG WINDROW
50
SLOPE BUTTRESS OR
REPLACEMENT FILL DETAIL
OUTLET PIPES
4" 0 Nonperforoted Pipe,
100' Max. O.C. Horizontally,
30' Max. O.C. Vertically
\ss
FILLBLANKE
30" MIN.
BACK CUT
OR FLATTEF
BENCHING
SUBDRAIN
SEE ALTERNATES A &
FILTER MATERIAL
3 II. 3/ll.
CONNECT
ALTERNATE A
1
21 M|K|/VUlN.
T-OO/ IA; -/^
TEMPORARY ^
/ FILL LEVEL
unf:m9
-i£-RECOMPACTED FILL
TJ. SELECT BEDDINO
BACKFILL
FILTER MATERIAL
Fitter material shall be
Class 2 permeable material
per State of Calitornia
Standard Specifications,
or approved alternate.
Class 2 grading as follows:
c
c
I-
>4*ev,IN. NONPERFORATED
PIPE
DETAIL A-A'
NOTES:
• Fill blanket, back cut. key width and
key depth are subject to field change,
per report/plans.
• Key heel subdrain, blanket drain, or
vertical drain may be required at the
discretion of the geotechnical consultant.
• SUBDRAIN INSTALLATION - Subdrain
pipe shall be installed with perforations
clown or. nt locations designated by
the geotechnical consultant, shall be
nonperforated pipe.
SUBDRAIN TYPE - Subdrain type shall
be ASTM C508 Asbestos Cement Pipe
(ACP) or ASTM D275I, SDR 23.5 or ASTM
DI527. Schedule 40 Acrylonitrile Butadiene
Styrene (ARS) or ASTM D3034 SDR 23.5
or ASTM DI785. Schedule 40 Polyvinyl
Chloride Plastic (PVC) pipe or approved
equivalent.
10* nlN. EACH SIDE
I ["".CAP FOt
ALT. D
SIEVE SIZE
r
3/4'
3/8*
No. 4
No. 8
No. 30
No. 50
No. 200
PERCENT PASSir
100
90-100
40-100
25-40
18-33
5-15
0-7
0-3
POSITIVE SEAL
SHOULD BEPROVIDEDAT THE JOINT
3%
FILTER FABRIC(MIRAFI HO OnAPPROVED EQUIVALENT)
ALTERNATE B
DETAIL OF BUTTRESS SUBDRAIN TERMINAL
DESIGU FUJI SM£D GRADE-
MATIVE
10's
flLTE* TAtWIC(MIHAFI uo on
APPrUlVtDEQUIVALCI.'I)
IX- .••.*•••. •/.*?>?:;;. , .
-15' KIN.'HIN.H -" \
lk*MAX.Ira.uri
— MONPEirORATED «"e "IN. "~
i"t mil. PIPE
iAX.OPEN GRADED
CRAVCL OR APPROVEDEQUIVALENT
CANYON SUBDRAIN DETAIL
BENCHING
NATURAL GROUND
.-COMPACTED FILL - ---
REMOVE
UNSUITABLE
MATERIAL
SUBDRAIN TRENCH
SEE ALTERNATES A&B
SUBDRAIN Perforated Pipe Surrounded With
ALTERNATE A: Filter Material
FILTER MATERIAL-
PERFORATED PIPE'
6" 0 MIN.
FILTER MATERIAL
Filter material shall be
Class 2 permeable material
per State ol California
Standard Specifications,
or approved alternate.
Class 2 grading as follows:
SIEVE SIZE
T
3/4'
3/8'
No. 4
No. 8
NO. 30
No. 50
No. 200
PERCENT PASSING
10090-100
40-100
25-40
18-33
5-15
0-7
0-3
SUBDRAINALTERNATE B:
1 1/2" Gravel WrappedIn Filter Fabric
6" MIN. OVERLAP
FILTER FABRIC
(MIRAFI 140—
OR APPROVED
EQUIVALENT
h-
5S
DETAIL OF CANYON SUBDRAIN TERMINAL
DESIGN FINISHED GRADE-
&
FILTER FABRIC
APPnOVCD EQUIVALENT)
/?"MAX.GRAVEL OR — Alternate B-Z
APPROVED EQUIVALENT
9 ft. 3/ft.
Ik MAX.OPEN GRADED
GRAVEL OR APPROVEDEQUIVALENT
• SUBDRAIN INSTALLATION - Subdroin pipe shall be installed with perforations down or,
at locations designated by the geotechnical consultant, shall be nonperforated pipe.
• SUBDRAIN TYPE - Subdrain type shall be ASTM C508 Asbestos Cement Pipe (ACP) 52
or ASTM D275I, SDR 23.5 or ASTM DI527, Schedule 40 Acrylonitrile Butadiene Styrene
(ABS) or ASTM D3034 SDR 23.5 or ASTM DI785, Schedule 40 Polyvinyl Chloride Plastic
(PVC) pipe or approved equivalent.
SIDE HILL
CUT PAD DETAIL
NATURAL.
GROUND >-'
\sr
L
I
OVEREXCAVATE
AND RECOMPACT
(REPLACEMENT
OVERBURDEN —,
OR UNSUITABLE
MATERIAL
£1FINISHED CUT PAD
Pad over excavation and recompaction
shall be performed if determined to
be necessary by the geotechnical
consultant.
UNWEATHERED BEDROCK OR
MATERIAL APPROVED BY
THE GEOTECHNICAL CONSULTANT
SUBDRAIN AND KEY WIDTH REQUIREMENTS
DETERMINED BASED ON EXPOSED SUBSURFACE
CONDITIONS AND THICKNESS OF OVERBURDEN
I
I
L-
53
3T
HNPT^Tj^CS
'a*
*>
,{
i i i i i i I I i I i f i I i
,#*•
J\
Locations of Borings for R Curve Test
R-VALUE DATA SHEET
n
\
EXUDATION PRESSURE (PSI)
o.
R-VALUE DATA SHEET o-f
BATCH WT1HUMID MOIST
WATER ADDED
GROSS WT
MOLD TARE
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Appendix 2:
General Earthwork and Grading Specifications
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APPENDIX 2
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
1.0 General Intent
These specifications present general procedures and requirements for grading and
earthwork as shown on the draft grading plan, including preparation of areas to be filled,
placement of fill, installation of subdrains, and excavations. The recommendations
contained in the geotechnical report are a part of earthwork and grading specifications and
shall supersede the provisions contained hereinafter in the case of conflict. Evaluations
performed by the consultant after detailed grading plan is approved and during the course
of grading may result in new recommendations which could supersede these specifications
or recommendations of the geotechnical report.
2.0 Earthwork Observation and Testing
Prior to the commencement of grading, a qualified geotechnical consultant (soils engineer
and engineering geologist; and their representatives) shall be employed for the purpose of
observing earthwork procedures and testing the fills for conformance with the
recommendations of the geotechnical report and these specifications. It will be necessary
that the consultant provide adequate testing and observation so that he may determine that
the work was accomplished as specified. It shall be the responsibility of the contractor to
assist the consultant and keep him appraised of work schedules and changes so that he
may schedule his personnel accordingly.
It shall be the sole responsibility of the contractor to provide adequate equipment and
methods to accomplish the work in accordance with applicable 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, poor moisture condition,
inadequate compaction, adverse weather, etc., are resulting in a quality of work less than
required in these specifications, the consultant will be empowered to reject the work and
recommend that construction be stopped until the conditions are rectified.
Maximum dry density tests used to determine the degree of compaction will be performed in
accordance with the American Society for Testing and Materials test method ASTM D1557.
3.0 Preparation of Areas to be Filled
3.1 Clearing and Grubbing: All brush, vegetation and debris shall be removed or piled
and otherwise disposed of.
3.2 Processing: The existing ground which is determined to be satisfactory for support
of fill shall be scarified to a minimum depth of 6 inches. Existing ground which is not
satisfactory shall be overexcavated as specified in the following section. Scarification
shall continue until the soils are broken down and free of large clay lumps or clods
and until the working surface is reasonably uniform and free of uneven features
which would inhibit uniform compaction.
3.3 Overexcavation: Soft, dry, spongy, highly fractured or otherwise unsuitable ground,
extending to such a depth that surface processing can not adequately improve the
condition, shall be overexcavated down to firm ground and approved by the
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consultant.
3.4 Moisture Conditioning: Overexcavated and processed soils shall be watered,
dried-back, blended, and/or mixed, as required to attain a uniform moisture content
near optimum.
3.5 Recompaction: Overexcavated and processed soils which have been properly
mixed and moisture-conditioned shall be recompacted to a minimum relative
compaction of 90 percent.
3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1
(horizontal to vertical units), the ground shall be stepped or benched. The lowest
bench shall be a minimum of 15 feet wide, shall be at least 2 feet deep, shall expose
firm materials, and shall be approved by the consultant. Other benches shall be
excavated in firm materials for a minimum width of 4 feet. Ground sloping flatter than
5:1 shall be benched or otherwise Overexcavated when considered necessary by the
consultant.
3.7 Approval: All areas to receive fill, including processed areas, removal areas and
toe-of-fill benches shall be approved by the consultant prior to fill placement.
4.0 Fill Material
4.1 General: Material to places as fill shall be free of organic matter and other
deleterious substances, and shall be approved by the consultant. Soils of poor
gradation, expansion, or strength charecteristics shall be placed in areas designated
by the consultant or shall be mixed with other soils to serve as satisfactory fill
material.
4.2 Oversize: Oversize material defined as rock, or other irreducible material with a
maximum dimension greater than 12 inches, shall not be buried or placed in fills,
unless the location, materials, and disposal methods are specifically approved by the
consultant. Oversize disposal operations shall be such that nesting of oversize
material does not occur, and such that the oversize material is completely
surrounded by compacted or densified fill. Oversize material shall not be placed
within 10 feet vertically of finish grade or within the range of future utilities or
underground construction, unless specifically approved by the consultant.
4.3 Import: If importing of fill material is required for grading, the import material shall
meet the requirements of Section 4.1.
5.0 Fill Placement and Compaction
5.1 Fill Lifts: Approved fill material shall be placed in areas prepared to receive fill in
near-horizontal layers not exceeding 6 inches in compacted thickness. The
consultant may approve thicker lifts if testing indicates the grading procedures are
such that adequate compaction is being achieved with lifts of greater thickness.
Each layer shall be spread evenly and shall be thoroughly mixed during spreading to
attain uniformity of material and moisture in each layer.
5.2 Fill Moisture: Fill layers at a moisture content less than optimum shall be watered
and mixed, and wet fill layers shall be aerated by scarification or shall be blended
with drier material. Moisture-conditioning and mixing of fill layers shall continue until
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the fill material is at a uniform moisture content at or near optimum.
5.3 Compaction of Fill: After each layer has been evenly spread, moisture-conditioned,
and mixed, it shall be uniformly compacted to not less than 90 percent of maximum
dry density. Compaction equipment shall be adequately sized and shall be either
specifically designed for soil compaction or of proven reliability, to efficiently achieve
the specified degree of compaction.
5.4 Fill Slopes: Compacting of slopes shall be accomplished, in addition to normal
compacting procedures, by backrolling of slopes with vibrating rollers at frequent
increments of 2 to 3 feet in fill elevation gain, or by other methods producing
satisfactory results. At the completion of grading, the relative compaction of the
slopes out to the slopes shall be at least 90 percent.
5.5 Compaction Testing: Field tests to check the fill moisture and degree of
compaction will be performed by the consultant. The location and frequency of tests
shall be at the consultant's discretion. In general, the tests will be taken at an interval
not exceeding 2 feet in vertical rise and/or 1000 cubic yards of embankment.
6.0 Subdrain Installation
Subdrain systems, if required, shall be installed in approved ground to conform to the
approximate alignment and details that will be shown on the proposed plans. After
approval of subdrains, the subdrains location or materials shall not be changed or modified
without the approval of the consultant. The consultant, however, may recommend and
upon approval, direct changes in subdrain line, grade or material. All subdrain should be
surveyed for line and grade after installation and sufficient time shall be allowed for the
surveys, prior to commencement of filling over the subdrain.
7.0 Excavation
Excavation and cut slopes will be examined during grading. If directed by the consultant,
further excavation or overexcavation and refilling of cut areas shall be performed, and/or
remedial grading of cut slopes shall be performed. Where fill-over-cut slopes are to be
graded, unless otherwise approved, the cut portion of the slope shall be made and
approved by the consultant prior to placement of materials for construction of the fill portion
of the slope.
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Appendix 3:
Homeowner's Guidelines for Slope Maintenance
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APPENDIX 3
HOMEOWNER'S GUIDELINES FOR SLOPE MAINTENANCE
Many owners of new hillside homes do not realize that their property is in need of special
maintenance. Too often hillside homeowners become lax in proper maintenance of slope and
drainage devices, resulting in catastrophic consequences.
Homeowner's Guidelines for Slope Maintenance is designed to familiarize property owners with
features of their newly acquired property with which they may not be acquainted.
Governing agencies require hillside property developers to utilize specific methods of engineering
and construction to protect those investing in improved lots or constructed homes. For example,
the developer may be required to grade the property to grade the property in such a manner that
rainwater will safely leave the lot and to plant slopes so that erosion will be kept to an absolute
minimum. He may be required to install permanent drains.
However, once the lot is purchased, it is the buyer's responsibility to maintain these safety
features by observing a prudent program of lot care and maintenance.
The owner who overlooks regular inspection and maintenance of drainage devices and sloping
areas may expose himself to severe financial loss. In addition to his own property damage, he
may be subject to civil liability for damage occurring to neighboring properties as a result of his
negligence.
The following guidelines are for the protection of the buyer's investment and are of paramount
importance:
1. Care should be taken that slopes, terraces, berms (ridges at crown of slopes) and proper
drainage are not disturbed. Surface drainage should be conducted from the rear yard,
through the side yard, to the street.
2. All roof and yard runoff should be conducted to either the street or storm drain by
nonerosive devices such as sidewalks, drainage pipes, ground gutters, driveways, etc.
Driveway runoff should be conducted to the street in such a manner as to inhibit small soil
failures. Do not alter your drainage without first obtaining expert advice.
3. Keep all drains cleaned and unclogged, including gutters and downspouts. During heavy
rain periods, inspect drainage performance often, as this is when occurs. Watch for
gullying and pounding. Correct problems as soon as possible.
4. Any leakage from pools, waterlines, etc. or bypassing of drains should be promptly
repaired.
5. Eliminate animal burrows and animals that make them, as they can cause diversion of
surface runoff, promote accelerated erosion, and even bring about shallow soil flowage.
6. Never alter your slopes without expert advice. If your lot is built on fill, or partly on fill,
consult with a soil engineer whenever you contemplate significant topographic modification
of the lot. Do not spread loose fill over slopes.
7. Should you contemplate modification of manufactured or natural slopes within your
property, consult an engineering geologist. Any oversteepening may result in the need for
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expensive retaining devices. The undercutting of a toe-of-slope may reduce the designed
safety factor which may result in slope failure.
8. If unusual cracking, settling or earth slippage occurs, consult a qualified soil engineer or an
engineering geologist immediately.
9. Be careful with piecemeal or homemade approaches to repair of slope instability as this can
result in exasperation of instability problems.
10. Remember that most common causes of slope erosion and shallow slope failure are:
a. Gross neglect in the care and maintenance of the slopes and drainage devices.
b. Inadequate and/or improper planting. (Replant barren areas as soon as possible)
c. Too much irrigation or diversion of runoff over the slope. (Keep plants watered, but do
not overwater)
11. Do not let conditions on your property create a problem for your neighbors. By working
together with neighbors to prevent problems, you can not only promote slope stability,
adequate drainage and proper maintenance, but also increase the aesthetic attractiveness
of the community.
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