HomeMy WebLinkAboutCDP 05-38; BAGNALL RESIDENCE; GEOTECHNICAL AND GEOLOGIC INVESTIGATION; 2005-12-20I
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ENGINEERING
DESIGN GROUP
GEOTECHNICAL, CIVIL & STRUCTURAL CONSULTANTS
FOR RESIDENTIAL & COMMERCIAL CONSTRUCTION
2121 Montiel Road, San Marcos, California 92069 • (760) 839-7302 • Fax: (760) 480-7477 • E-mail: ENGDG@aol.com
GEOTECHNICAL AND GEOLOGIC INVEST/GA TION,
PROPOSED 2N° STORY ADDITION TO THE BAGNALL RESIDENCE,
LOCATED AT 5029 TIERRA DEL ORO STREET
CARLSBAD, CALIFORNIA
EOG Project Number 053776-1
Dated: December 20, 2005
PREPARED FOR:
EMILY BAGNALL
P.O. Box 629
Rancho Santa Fe, CA 92067.
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TABLE OF CONTENTS
Page
SCOPE ..................................................................... 1
SITE AND PROJECT DESCRIPTION ............................................. 1
BLUFF DESCRIPTION ........................................................ 2
FJELD INVEST/GA TION ....................................................... 2
SUBSOIL CONDITIONS ....................................................... 2
GEOLOGIC STRUCTURE ..................................................... 3
FAULTS .................................................................... 3
TSUNAMI ................................................................... 4
GROUNDWATER AND SURFACE WATER ........................................ 4
COASTAL BLUFF RETREAT ................................................... 5
COASTAL BLUFF-EDGE RETREAT RA TES ....................................... 5
SLOPE STABILITY CALCULATION .............................................. 6
GEOLOGIC AND GEOTECHNICAL CONCLUSIONS ................................ 7
BLUFF RETREAT ...................................................... 7
SLOPE STABILITY EROSION ............................................ 7
BLUFF TOP SETBACK .................................................. 8
PROPOSED BUILDING CONSTRUCTION .................................. 8
SEISMIC CONSIDERATION .............................................. 8
GEOTECHNICAL RECOMMENDATIONS ......................................... 8
EARTHWORK ......................................................... 8
FOUNDATIONS ........................................................ 9
Existing Foundations .............................................. 9
New Foundations ................................................. 9
CONCRETE SLABS ON GRADE ......................................... 10
RETAINING WALLS . . . . . . . . . . . . . . . . . . . . . . . . . ....................... 12
SURFACE DRAINAGE ................................................. 13
CONSTRUCTION OBSERVATION AND TESTING ................................. 14
MISCELLANEOUS .......................................................... 15
ATTACHMENTS
Site Vicinity Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure No. 1
Site Location Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure No. 2
Site Plan/Location of Exploratory Borings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure No. 3
Boring Logs ....................................................... Borings 1 & 2
References .......................................................... Appendix A
Slope Stability Analysis ................................................ Appendix B
Retaining Wall Drainage Detail .......................................... Appendix C
Cross Sections, Geologic Map, Photos .................................... Attachment
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SCOPE
This report presents the results of our limited geotechnical investigation and geologic evaluation for
the proposed new second story additions to the existing residence at 2029 Tierra del Oro, in the City
of Carlsbad, California. Please see Figure No. 1, "Site Vicinity Map", and Figure No. 2, "Site
Location Map". The purpose of our study was to evaluate the geologic and geotechnical conditions
at the coastal property and provide recommendations relative to the proposed construction. The
scope of our work has included the following:
► Review of aerial photographs, topographic maps, geologic literature, in house reports and
project plans pertaining to the site and general vicinity. A list of the items reviewed is
presented in Appendix A.
► Limited subsurface geotechnical investigation of onsite soil condition.
► Geologic reconnaissance to observe the existing site conditions including the coastal bluff
and general vicinity.
► Photo documentation of conditions observed.
► Preparation of a generalized profile of the bluff face at the subject property.
► Geotechnical analysis of the data obtained including a computer-generated slope stability
analysis of the coastal bluff.
► Preparation of this report summarizing the results of our geotechnical evaluation.
SITE AND PROJECT DESCRIPTION
For the purpose of this report, the front of the residence is assumed to face east. The subject
property consists of a rectangular lot located on the west side of Tierra def Oro, in the City of
Carlsbad, California. The property is bordered to the north and south by single family residences,
to the west by a descending coastal bluff (approximately 20 feet high), and to the east by Tierra del
Oro. The topography of the site generally consists of a relatively flat building pad, flanked to the
west by both an upper and lower patio. The upper patio extends out from the house
approximate1~112 feet, then descends approximately 4 vertical feet to the lower patio, which
measures approximately 16 feet wide. There appears to be a storm drain easement along thE:· south
side of the property. Beyond the lower patio, the slope (hereafter referred to 2s bluff) desc~nds at
an approximately 2:1 slope face inclination to large rip rap and the beach.
Currently the site is improved with a one story single family residence. Other improvements
consists of terraced masonry site walls at the rear patios, concrete and stone hardscape. At the
time of our investigation the flatwork and patios show no obvious evidence of cracking or settlement
type cracking or other influences that may be associated with bluff movement.
Based upon conversations with the project designer we understand the proposed site modifications
will consist of the following:
► Construction of second story additions to the existing residence.
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTuRil & ARCHITECTURAL CONSULTANTS
Page No.1
Job No. 053776-1
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BLUFF DESCRIPTION
Cross sections, a geologic map and photographs depicting the general configuration of the bluff are
provided in the enclosed attachment. The following is a summary of the onsite bluff conditions.
The bluff flanking the western side of the site consists of an 20-foot high coastal bluff (see
Attachment). At the base of the slope is a large rip rap serving as a reventment, protecting the bluff
from concentrated erosion and undermining. Indications of sea cave development were not
observed at the site. The bluff is heavily vegetated with ice plant and generally not undermined.
The protruding configuration of sandstone tributary to the site serves as a natural reventment,
FIELD INVEST/GA TION
Our field investigation of the property, conducted on November 1, 2005, consisted of a site
reconnaissance, site field measurements, observation of existing conditions on site and adjacent
public access lands and a limited subsurface investigation of soil conditions. Our subsurface
investigation included excavation of two exploratory borings, logging of soil types encountered and
sampling of soils for laboratory testing. Logs of the borings are presented in Figures No. 4 and 5
of this report. The locations of the borings are given in Figure No. 3, "Site Plan/Location of
Exploratory Borings".
SUBSOIL CONDITIONS
Soil types encountered within our borings are described as follows:
Topsoil/Fill:
Topsoil/fill materials were en(:ountered tu a depth of 18 24 inc+ies below adjacent grade in
our borings. Topsoil/fill materials consist of dark brown, slightl\1 moist to moist, medium
dense, slightly silty sands. These materials are not consit.lered suitable for the support
of structures and structural improvements. All new footings should extend through
fill profiles and all existing foundations receiving new loads shall be underpinned.
Fill materials classify as SW-SM according to the Unified Soil Classification System, and
based on visual observation, are considered to possess low potential for expansion.
Terrace Deposits (Qbp):
Terrace Deposits (sandstone) were found to underlie the fill material within boring
excavations. Terrace Deposits consist of rust to light brown, slightly moist to moist, dense,
very slightly silty sand. These materials are considered suitable for the support of
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
Page No.2
Job No. 053776-1
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structures and structural improvements, provided the recommendations of this
report are followed. Terrace Deposits classify as SW-SM according to the Unified Soil
Classification System, and based on visual observation and our experience, possess an
potential for expansion in the low range.
Santia(.lo Formation
Santiago formation was found below Terrace Deposits within our borings and observed in
the vicinity of the site. Santiago formation consists of white, moist, very dense, sandstone.
These materials are considered suitable for the support of structures and structural
improvements, provided the recommendations of this report are followed. Santiago
formation classifies as SW-SM according to the Unified Soil Classification System, and
based on visual observation and our experience, possess an expansion potential of low.
For detailed logs of soil types encountered within our exploratory borings, as well as a depiction of
the boring location, please see Figure No. 3, "Site Plan/Location of Exploratory Borings", and
Figures No. 4-5 , "Boring Logs".
GEOLOGIC STRUCTURE
The Santiago Formation is exposed in the wave-cut platform in the vicinity of the subject property
is nearly flat-lying. In the general vicinity, bedding in the Quarternary terrace depo5its can be
observed as alternating more resistant and less resistant beds. Where observed on site and in the
general site vicinity, the terrace deposits appear to be horizontally bedded with localized cross
bedding.
No major out-of-slope dip components were noted on site that would indicate adverse slope
conditions. Indications of deep-seated landslide features were not observed during our research
studies or site visits.
FAULTS •
Our review of geologic literature (Appendix A) pertaining to the general site area indicates that there
are no known major or active faults on or in the immediate vicinity of the site. Indications of active
faulting or adversely-oriented joints were not observed in the subject coastal bluff. The nearest
known active faults are the Rose Canyon fault located offshore approximately 4 miles west of the
site, the Coronado Bank fault located offshore approximately 19.5 miles west, and the Elsinore fault
located approximately 25 miles northeast of the site. The San Andreas fault is located
approximately 62 miles northeast of the site.
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
Page No.3
Job No. 053776-1
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TSUNAMI
Tsunami are sea waves generated by submarine earthquakes, landslides, or volcanic action.
Submarine earthquakes are common along the edge of the Pacific Ocean and coastal areas are
subject to potential inundation by tsunami. Most of the 19 tsunami recorded on the San Diego Bay
tidal gauge (between 1854 to 1872 and 1906 to 1977) have only been a few tenths of a meter in
height (Appendix A). The largest San Dieg0 area tidal gauge excursion (1 meter) was associated
with the tsunami of May 22, 1960 and was recorded at La Jolla (Scripps Pier) (AppendixA). The
tsunami was generated by a Richter magnitude 8.5 earthquake in Chile. For comparison, the
diurnal range oftides at San Diego Bay is 1. 7 meters. The possibility of a destructive tsunami along
the San Diego coastline is considered low (Appendix A). However tsunami or storm waves
(associated with winter storms), in conjunction with high tides, may overtop the rock rip rap and
erode the friable terrace deposits that compromise the coastal bluff face but generally are not
anticipated to have the potential for inundation of the bluff-top building site.
GROUNDWATER AND SURFACE WATER
Groundwater seepage was not observed on site or in the general site vicinity during our site visits
Based on our experience and observations, groundwater is estimated to lie at or near sea level at
the base of the coastal bluff. Groundwater levels can be expected to fluctuate with the tides,
precipitation and irrigation at the subject and neighboring properties. Groundwater is not considered
a constraint to the proposed new residence. However, in our experience, groundwater conditions
can develop where no such condition previously existed. The bluff-top surface waters shall be
directed to the storm drain along the south of the property or drain toward Tierra del Oro.
COASTAL BLUFF RETREAT
The coastline in the vicinity of the subject property is straight with slight indentations along its length
(see Figure 1 ). The site is located on one of the headlands along the coast. Mechanisms for
cr>1s+dl bluff retreat at the site include abrasion and und.:;, cutting b\' ni, rir.e e'"osion (wave action)
of the terrace deposits. The existing rock rip rap !"er.luces the potential for ercsion -of the onsite
coastal bluff. Storm surf and high tides contribute to the natural process uf marine erosion. Other
factors affecting the rate of retreat of the coastal bluff include degree of fracturing, jointing,
consolidation of sediments, steepness of slope, groundwater and surface water conditions,
vegetation or lack of, and intensity of pedestrian and animal traffic.
In response to the landward retreat of the bluff, the overlying coastal bluff becomes undermined and
also retreats landward. Mechanisms contributing to bluff retreat include failure of overhanging
bedrock projections, shallow failure of oversteepened portions of the bluff-face terrace deposits, and
rilling and ravelling of the terrace deposits. Portions of coastal bluffs are also exposed to
precipitation, wind, pedestrian/animal erosion, variations in landscape, landscape maintenance, and
other activities by humans.
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
Page No.4
Job No. 053776-1
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]
During our studies we did not observe indications of deep-seated instability, such as ancient or
active landslides, on or in the immediate vicinity of the site, and the geologic formations that
comprise the coastal bluff at the site are not known to be prone to large, deep-seated failures. The
terrace deposits are friable and commonly rill in oversteepened slope conditions, however they are
not prone to deep-seated failures.
COASTAL BLUFF-EDGE RETREAT RATES
The rate and magnitude of coastal bluff retreat at a specific site are dependent on a variety of
factors, both natural and manmade. Many of these factors are ongoing processes and historical
documentation can be helpful in estimating general retreat rates along similarly-affected coastal
bluff areas. However, there are other factors affecting coastal bluff retreat that cannot be estimated
from historic documentation. Such factors include future human activities or possible extreme
variations in regional weather patterns.
Detrimental changes in factors affecting bluff-edge retreat, such as misdirected drainage, water line
breaks, heavy storm surf and/or precipitation, could increase the rate of erosion. However, favorable
changes in the factors affecting bluff-edge retreatcould also decrease the rate of erosion. Some
of these include proper maintenance of a bluff-stabilizing vegetative cover, enhanced site drainage
provisions and beach sand replenishment.
Research studies along the San Diego coast and historic photograph and map review are
components in providing an estimation of the rate of bluff-edge retreat. We assume that the
historical retreat rate may give an indication of the future retreat rate at a particular site. However,
accurate and clear photographic and map documentation for measuring retreat is not always
available or are of fairly short time intervals so changes may not be noticeable.
Lee and others (Appendix A), performed research studies of regional historic sea cliff retreat and
estimated a maximum annual bluff-edge retreat rate of 0.22 to 0.33 feet per year. Over a 75-year
period (assumed to be the e·:Jnomic liff'tirr'3 ofth'3 new construction), this equates to a conser •·'.tive
estimate of bluff-edge retreat of a ma,<imum of 1 n.5 to 24.8 feet. This maximum is based on
research studies of regional historic bluff retre.Jt that includes coastal bluffs v. ith generally favo(ablL'
conditions, as well as coastal bluffs that are affected by more adverse conditions (highly fractured,
sea caves, groundwater seepage, human activities, etc.). The estimated values oftaximumretreat
are very conservative, and the actual rate of bluff retreat at the subject property is expected to be
less considering the site conditions and historic bluff retreat at the site.
Sea cave formation and subsequent collapse are localized factors in the bluff retreat process.
Indications of sea cave development were not observed at the subject property during our site visits.
It is very difficult to predict the future and the magnitude of bluff-edge retreat that may occur in one
year, during one storm event or over the 75-year assumed economic lifetime of the new
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
Page No.5
Job No. 053776-1
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construction. The rate of coastal bluff retreat over a particular interval of time (day, year, decade,
etc.) may vary from very little to several tenths of a foot. However, severe erosion is generally
episodic in nature and is dependent on the intensity of storms and combined high tides (orman's
detrimental actions). It is probable that several feet of coastal bluff retreat could occur at one time.
However, it is also likely that there will be periods in the future when erosion along the coast is
rather insignificant and undetectable. Erosion is a naturally-occurring process that is affected by
human actions. With time, the bluff edge will retreat landward.
It is our opinion that the new construction, proposed to be set back a minimum of 10 feet from the
bluff edge, will not be endangered by coastal bluff retreat over the next 75 years.
SLOPE STABILITY CALCULATIONS
A computer-generated slope stability analysis was performed on the coastal bluff at the site. The
slope stability was analyzed using 'Janbu's Modified Method' with the XSTABLE compute1 program.
The slope stability calculations are included in Appendix D. The soil strength parameters used in
our analysis are presented below. These values are based on laboratory test results,
back-calculation, our past experience in this area, and our professional judgement.
Slope Stability Soil Parameters
Soil Type Soil No: Unit Weight Friction Cohesion
Moist Angle (psf)
(pcf) (deg)
Terrace 2 120 35 100
Deposits
Santlaci-; 1 120 3::;·
-~-
~-00
l __ Formation ..
Based on our analysis, it is our opinion that the existing coastal bluff has a factor of safety greater
than 1.5 (static conditions) and 1.1 (pseudo static conditions) against deep-seated instability (See
Appendix D for specific analysis). Our modeling includes varied cross sections, circle and block
type analysis, earthquake forces and assumption of unfavorable geologic conditions.
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
Page No.6
Job No. 053776-1
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CONCLUSIONS AND RECOMMENDATIONS
GEOLOGIC AND GEOTECHNICAL CONCLUSIONS
Bluff Retreat
Based on our geologic evaluation and limited geotechnical investigation at the site, it is our opinion
that the proposed additions to the existing residence is feasible from a geotechnical standpoint. It
is our opinion that the proposed new second story will not adversely impact the existing coastal
bluff. Based on our field studies, research and engineering and geologic analysis, it is our opinion
the proposed construction should not be affected by the maximum anticipated coastal bluff retreat
processes during its economic lifetime (assumed to be 75 years) if the addition is set back a
minimum of 10 feet from the bluff edge as planned and mapped herein.
Slope Stability and Erosion
Our geotechnical evaluation of the present overall static stability on the subject property indicates
that the bluff is grossly stable. In its present state, the slope has a low to moderate potential for
erosional rilling and future surficial instability. We provide the following recommendationsto help
reduce erosion of the bluff and to reduce potential for future instability of the bluff face.
1. Irrigation of the landscape areas on the property should be curtailed, and limited to manual
irrigation within the coastal bluff setback zone. The amount of manual irrigation onsite should
be limited to theminimum amount required to establish vegetation and maintain plant vigor.
The upper portion of the subject coastal bluff and the bluff edge are currently densely
vegetated. At this time, it is our opinion that modifications to the vegetation should not be
considered.
2. Adequate drainage precautions at this site are imperative and will play a critical role on the
future performance of the blv~, dwelling and improvements. Under no circumstances should
surface water be allowed to pond or flov, to1: ·ard tho bluff. Roof gutters and downspouts shall
be installed on the new and existing structures and dghtlined to the area drain system. All
drains should be kept clean and unclogged, including gutters and downspouts. All surface
runoff water should drain away from the structure and top of bluff with a minimum slope of
2% for a horizontal distance of 7 feet (where possible). Area drains or surface swales should
then be provided to accommodate runoff and avoid any ponding of water. The area drain
system shall consists of non perforated smooth wall drainage pipe (PVC SDR-35 or better)
with chemically welded joints, as sized and designed by the project civil engineer. Area
drains should be kept free of debris to allow for proper drainage. During fine grading of the
property, subsequent building construction, adequate clearance shall be left from finish soil
grade to building framing lumber as prescribed by code. It is advisable to meet with the .
project landscaper during this phase of the project so that proposed import topsoil may be
accounted for in determining finish grade elevation against the building stemwall.
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
Page No.7
Job No. 053776-1
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During periods of heavy rain, the performance of all drainage systems should be inspected.
Problems such as gullying or ponding should be corrected as soon as possible. Any leakage
from sources such as water lines should also be repaired as soon as possible. In addition,
irrigation of planter areas, lawns, or other vegetation, located adjacent to the foundation or
exterior flat work improvements, should be strictly controlled or avoided.
3. Pedestrian and animal traffic on the bluff face and bluff edge should not be allowed since
pedestrian/animal traffic increases erosion.
Bluff-Top Setback
Based on our review of the project plans, the proposed new residence will be set back a minimum
of 1 O feet from the bluff edge. It is our opinion that the proposed setback will safeguard the
proposed construction from bluff-edge retreat during the economic lifetime of the addition.
Proposed Building Construction
The proposed site construction will construction of second story additions to the existing single story
residence. As we understand the proposed new additions will not extend beyond, i.e. towards the
bluff face, beyond the existing footprint. In general, the proposed building construction as currently
proposed will not pose an increase threat to the stability of the bluff.
Seismic Considerations
Ground shaking would be the primary seismic hazard at the site. The possibility of ground rupture
is considered minimal since no active faults are known to cross the site. The potential for
liquefaction or seismically-induced ground settlement is very low. In general, the role seismic
shakin_g plays in bluff retreat is dependent on bluff conditions at the morr,ent of shaking. However,
it is our opinion th-at ·.-,e pot£.ncial for deep-seated or severe, catastrophic failure of ::-ie ,;caste;! bluff
property due to exp~cted seisinic ground ::;haking is low at the site. This conclusior is support-,3d
by our Pseudo static slope stability of the bluff w'1ich indicates a factor of safety in excess of 1.1.
GEOTECHNIC.AL RECOMMENDATIONS
Earthwork
It is our understanding earthwork will be limited to excavation of new foundations for the proposed
additions.
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL. CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
Page No.8
Job No. 053776-1
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Foundations:
Existing Foundations
At the time of our subsurface investigation the existing foundations could not be exposed.
Underpinning of the existing foundations may be necessary at the time of construction where new
loads are added to existing fmmdations. This condition should be identified, observed in field and
detailed on a case by case basis.
New Foundations
Where new foundations are designed for the proposed second story additions the following design
parameters may be utilized. All new foundations shall be deepened through topsoil/fill profiles to
competent formational material, anticipated to be 24 inches.
1.
2.
3
4.
Footings bearing in competent formational materials may be designed utilizing maximum
allowable soils pressure of 1,500 psf.
Seismic Design Parameters:
Seismic Zone Factor 4 . . ·• .
Soil Profile Type Sd
(Table 16-J)
Near Source Distance 6.4 kilometers
(Distance to Closest
Active Fault)
Seismic Source Type B
(Table 16-U)
Bearing values may be increased by 33% when considerir~ wind, seismic, or other short
duration loadings.
The following parameters should be used as a minimum, for designing footing width and
depth below lowest adjacent grade:
No. of Floors Minimum Footing Width *Minimum Footing Depth
Supported Below Lowest Adjacent
Grade
1 15inches 18 inches
2 15inches 18inches
3 18inches 24inches
BAGNALL RESIDENCE Page No.9
Job No. 053776-1 5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
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5.
6.
*Note: Actual footing depth may be deeper to achieve proper embedment into
competent soil material if mitigative grading is not conducted.
All footings should be reinforced with a minimum of two #4 bars at the top and two #4 bars
at the bottom (3 inches above the ground). For footings over 30 inches in depth, additional
reinforcement, and possibly a stemwall system will be necessary. This detail should be
reviewed on a case-by-case basis by our office prior to censtruction.
All isolated spread footings should be designed utilizing the above given bearing values and
footing depths, and be reinforced with a minimum of #4 bars at 12 inches o.c. in each
direction (3 inches above the ground). Isolated spread footings should have a minimum
width of 24 inches.
7. For footings adjacent to slopes, a minimum 10 feet horizontal setback informational material
or properly compacted fill should be maintained. A setback measurement should be taken
at the horizontal distance from the bottom of the footing to slope daylight. Where this
condition can not be met it should be brought to the attention of the Engineering Design
Group for review.
8. All excavations should be performed in general accordance with the contents of this report,
applicable codes, OSHA requirements and applicable city and/or county standards.
9. All foundation subgrade soils shall be pre-moistened a minimum of 18 inches in depth prior
to the pouring of concrete.
Concrete Slabs on Grade
No new concrete slabs are anticipated for the pmposed second story additions. Where concrete
slabs are specified the following as the minimum design parameters shall be utilized:
1. Concr-wte slabs on grade of the garage should have e minimum thick>'1ess of 4 inchP.s (5
inches at garage ana driveway locations) and should be reinforced with #4 bars at 13 inches
o.c. placed at the midpoint of the slab.
•
•
•
•
•
Slump: Between 3 and 4 inches maximum
Aggregate Size: 3/4 -1 inch
Air Content: 5 to 8 percent
Non-Moisture Sensitive Areas: Compressive Strength = 2500 psi minimum .
Moisture Sensitive Areas: Water to cement Ratio -0.5 maximum Compressive
Strength = 4,000 psi minimum (No special inspection required for water to cement
ratio purposes, unless otherwise specified by the structural engineer)
Moisture retarding additive in concrete at concrete slab on grade floors and moisture
sensitive areas.
BAGNALL RESIDENCE Page No.10
Job No. 053776-1 5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
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2.
3.
4.
5.
6
7.
All required fills used to support slabs, should be placed in accordance with the earthwork
section of this report and the attached Appendix B, and compacted to 90 percent Modified
Proctor Density, ASTM D-1557.
A uniform layer of 4 inches of r.lean sand is recommended under the slab in order to more
uniformly support the slab (sand equivalent <50), help distribute loads to the soils beneath
the slab, and act as a capillary break. In addition, a visqueen layer (10 mil) should be
placed mid-height in the sand bed to act as a vapor retarder.
Adequate control joints should be installed to control the unavoidable cracking of concrete
that takes place when undergoing its natural shrinkage during curing. The control joints
should be well located to direct unavoidable slab cracking to areas that are desirable by the
designer.
Ail subgrade soils to receive concrete flatwork are to be pre-soaked to 2 percent over
optimum moisture content to a depth of 24 inches.
Brittle floor finishes placed directly on slab on grade floors may crack if concrete is not
adequately cured prior to installing the finish or if there is minor slab movement. To
minimize potential damage to movement sensitive flooring, we recommend the use of slip
sheeting techniques (linoleum type) which allows for foundation and slab movement without
transmitting this movement to the floor finishes.
Exterior concrete flatwork and driveway slabs, due to the nature of concrete hydration and
minor subgrade soil movement, are subject to normal minor concrete cracking. To
minimize expected concrete cracking, the following may be implemented:
• Concrete slump should not exceed 4 inches.
• Concrete should be poured during "cool" ( 40 -65 degrees) weather if possible. If
concrete is poured in hotter weathe~, a set retarding additive should be included in
the mix, and the slump kept to a minimum.
c Concrete subgrade should be pre-soaked prior tc-the pourinJ of concrete. The level
of pre-soaking should be a minimum of 2% over optimum moisture to a depth d 24
inches.
• Concrete may be poured with a 10 inch deep thickened edge.
• Concrete should be constructed with tooled joints or sawcuts ( 1 inch deep) creating
concrete sections no larger than 225 sf. For sidewalks, the maximum run between
joints should not exceed 5 feet. For rectangular shapes of concrete, the ratio of
length to width should generally not exceed 0.6 (i.e., 5 ft. long by 3 ft. wide). Joints
should be cut at expected points of concrete shrinkage (such as male corners), with
diagonal reinforcement placed in accordance with industry standards.
BAGNALL RESIDENCE Page No.11
Job No. 053776-1 5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
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• Drainage adjacent to concrete flatwork should direct water away from the
improvement. Concrete subgrade should be sloped and directed to the collective
drainage system, such that water is not trapped below the flatwork.
• The recommendations set forth herein are intended to reduce cosmetic nuisance
cracking. The project concrete contractor is ultimately responsible for concrete
quality and performance, and should pursue a cost-beriefit analysis of these
recommendations, and other options available in the industry, prior to the pouring
of concrete.
Retaining Walls
Retaining walls are not anticipated for this project, but retaining walls up to 6 feet may be designed
and constructed in accordance with the following recommendations and minimum design
parameters:
1.
2.
3.
4.
5.
Retaining wall footings should be designed in accordance with the allowable bearing criteria
given in the "Foundations" section of this report, and should maintain minimum footing
depths outlined in "Foundations" section of this report. It is anticipated that all retaining wall
footings will be placed on competent formational sandstone. Where cut-fill transitions may
occur footings may be deepened to formational material or alternative detailing may be
provided by the Engineering Design Group on a case by case basis.
Unrestrained cantilever retaining walls should be designed using an active equivalent fluid
pressure of 35 pcf. This assumes that granular, free draining material with low potential
for expansion (E.I. <50) will be used for backfill, and that the backfill surface will be level.
Where soil with potential for expansion is not very low (E.1. >50) a new active fluid pressure
will be provided by the project soils engineer. Backfill materials should be considered prior
to the design of the retaining walls to ensure accurate detailing. We anticipate onsite
material will be utilized as retaining wall backfill. For sloping backfill, the following
parameters may be utilized·
-
Backfill Sloping Condition 2:1 Slope 1.5:1 Slope
Active Fluid Pressure 50 pcf 65 pcf
Any other surcharge loadings shall be analyzed in addition to the above values.
If the tops of retaining walls are restrained from movement, they should be designed for an
additional uniform at-rest soil pressure of 65 psf.
Passive soil resistance may be calculated using an equivalent fluid pressure of 300 pct.
This value assumes that the soil being utilized to resist passive pressures, extends
BAGNALL RESIDENCE Page No.12
Job No. 053776-1 5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
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6.
7.
8.
9.
horizontally 2.5 times the height of the passive pressure wedge of the soil. Where the
horizontal distance of the available passive pressure wedge is less than 2. 5 times the height
of the soil, the passive pressure value must be reduced by the percent reduction in available
horizontal length.
A coefficient of friction of 0.35 ~etween the soil and concrete footings may be utilized to
resist lateral loads in addition to the passive earth pressures above.
Retaining walls should be braced and monitored during compaction. If this cannot be
accomplished, the compactive effort should be included as a surcharge load when designing
the wall.
All walls shall be provided with adequate back drainage to relieve hydrostatic pressure, and
be designed in accordance with the minimum standards contained in the "Retaining Wall
Drainage Detail", Appendix D.
Retaining wall backfill should be placed and compacted in accordance with the following
recommendations. Backfill shall consist of soil with a very low expansion potential, granular,
free draining material.
a. Areas to receive fill and/or structural improvements should be scarified to a minimum
depth of 12 inches, brought to near optimum moisture content, and re-compacted
to at least 90 percent relative compaction (based on ASTM D1557-91 ). Compacted
fills should be cleaned of loose debris, oversize material in excess of 6 inches in
diameter, brought to near optimum moisture content, and re-compacted to at least
90% relative compaction (based on ASTM D1557-91 ). Surficial, loose or soft soils
exposed or encountered during grading (such as any undocumented or loose fill
materials) should be removed to competent formational material sandstone prior to
additional fill placement.
b. Fills should generally be placed in lifts not exceeding 8 inches in thickness. If the
import of soil is planned, soils should have ver:· lcN potential for expansion (E.I. <
50) and free of debris and organic matter. Prior to :mporting, .:.oils should he visually
observed, sampled and tested at the borrow pit area to evaluate soil suitability as fill.
SURFACE DRAINAGE
Adequate drainage precautions at this site are imperative and will play a critical role on the future
performance of the dwelling and improvements. Under no circumstances should water be allowed
to pond against or adjacent to foundation walls, or tops of slopes. The ground surface surrounding
proposed improvements should be relatively impervious in nature, and slope to drain away from the
structure in all directions, with a minimum slope of 2% for a horizontal distance of 7 feet (where
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
Page No.13
Job No. 053776-1
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possible). Area drains or surface swales should then be provided to accommodate runoff and avoid
any ponding of water. Roof gutters and downspouts shall be installed on the new and existing
structures and tightlined to the area drain system. All drains should be kept clean and unclogged,
including gutters and downspouts. Area drains should be kept free of debris to allow for proper
drainage.
During periods of heavy rain, the performance of all drainage systems should be inspected.
Problems such as gullying or ponding should be corrected as soon as possible. Any leakage from
sources such as water lines should also be repaired as soon as possible. In addition, irrigation of
planter areas, lawns, or other vegetation, located adjacent to the foundation or exterior flat work
improvements, should be strictly controlled or avoided.
CONSTRUCTION OBSERVATION AND TESTING
The recommendations provided in this report are based on subsurface conditions disclosed by our
investigation of the project area. Interpolated subsurface conditions should be verified in the field
during construction. The following items shall be conducted prior/during construction by a
representative of Engineering Design Group in order to verify compliance with the geotechnical and
civil engineering recommendations provided herein, as applicable. The project structural and
geotechnical engineers may upgrade any condition as deemed necessary during the development
of the proposed improvement(s).
1. Review of final approved structural plans prior to the start of work, for compliance with
geotechnical recommendations.
2. Attendance of a pre-grade/construction meeting prior to the start of work.
3. Testing of any fill placed, inqluding retaining wall backfill and utility trenches.
4. Observation of footing excavations prior to steel placement.
5. Field observation of any "field change" condition involving soils.
6. Walk through c_f final drainage detailing prior to final approval.
The project soils engineer may at their discretivn deepen footings or lor,ally recommend .:1dditional
steel reinforcement to upgrade any condition as deemed necessnry during site observations.
Engineering Design Group shall, prior to the issuance of the certificate of occupancy, issue in writing
that the above inspections have been conducted by a representative of their firm, and thedesign
considerations of the project soils report have been met. The field inspection protocol specified
herein is considered the minimum necessary for Engineering Design Group to have exercised "due
diligence" in the soils engineering design aspect of this building. Engineering Design Group
assumes no liability for structures constructed utilizing this report not meeting this protocol.
Before commencement of grading the Engineering Design Group will require a separate contract
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
Page No.14
Job No. 053776-1
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for quality control observation and testing. Engineering Design Group requires a minimum of 48
hours notice to mobilize onsite for field observation and testing.
MISCELLANEOUS
It must be noted that no structure or slab should be expected to remain totally free of cracks and
minor signs of cosmetic distress. The flexible nature of wood and steel structures allows them to
respond to movements resulting from minor unavoidable settlement of fill or natural soils, the
swelling of clay soils, or the motions induced from seismic activity. All of the above can induce
movement that frequently results in cosmetic cracking of brittle wall surfaces, such as stucco or
interior plaster or interior brittle slab finishes.
Data forth is report was derived from surface observations at the site, knowledge of local conditions,
and a visual observation of the soils exposed in the exploratory test pits. The recommendations in
this report are based on our experience in conjunction with the limited soils exposed at this site and
neighboring sites. We believe that this information gives an acceptable degree of reliability for
anticipating the behavior of the proposed structure; however, our recommendations are professional
opinions and cannot control nature, nor can they assure the soils profiles beneath or adjacent to
those observed. Therefore, no warranties of the accuracy of these recommendations, beyond the
limits of the obtained data, is herein expressed or implied. This report is based on the investigation
at the described site and on the specific anticipated construction as stated herein. If either of these
conditions is changed, the results would also most likely change.
Man-made or natural changes in the conditions of a property can occur over a period of time. In
addition, changes in requirements due to state of the art knowledge and/or legislation, are rapidly
occurring. As a result, the findings of this report may become invalid due to these changes.
Therefore, this report for the specific site, is subject to review and not considered valid after a period
of one year, or if conditions as stated above are altered.
It is the responsibility of the owner or his representative to ensure that the information in this report
be incorporated into the plans and/or specifications and construction of the project. It is advisable
that a contractor familiar with construction details typically used to deal with the !or.al subsoil and
seismic conditions, be retained to build the structure.
BAGNALL RESIDENCE
5029 TIERRA DEL ORO ST., CARLSBAD, CA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
Page No.15
Job No. 053776-1
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8
PROJECT NAME
PROJECT ADDRESS
JOB NUMBER
053776
SITE VICINITY MAP
BAGNALL RESIDENCE
5029 TIERRA DEL ORO, CARLSBAD, CALIFORNIA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL &ARCHITECTURAL CONSULTANTS 2121 M:lntiel Road, San Marcos, CA 92069
Phone: (760)839-7302 Fax: (760)480-7477
FIGURE
1
E:\FORMS\1 FRM\2000\MASTER -SITE VICINITY -FIG 1.wpd
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8
PROJECT NAME
PROJECT ADDRESS
JOB NUMBER
053776
I:•, · I
SITE LOCATION MAP
BAGNALL RESIDENCE
5029 TIERRA DEL ORO, CARLSBAD, CALIFORNIA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS 2121 Mmtlel Road, San Marcos, CA 92069
Phone: (760)839-7302 lloc (760)480-7477
SE/JM
F MA~
MUSI!
FLOM OF
PALI
:;ii
FIGURE
2
E:IFORMS\1 FRM\2000\MASTER -SITE LOCATION -FIG 2.wpd
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C. ,,·\
:\ ;-,----
?<'~~ ...... , ..
"':.>.p,j>_-,.vt:r,..,~
'
'
' ' '
7
_.------;~ ✓--.
/ ..... "' cf,,\,,-ll
\
\
\
PROJECT NAME
PROJECT ADDRESS
JOB NUMBER
053776
\
\
\
APPROXIMATE LOCATION OF 5oRfN~$
BAGNALL RESIDENCE
5029 TIERRA DEL ORO, CARLSBAD, CALIFORNIA
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL & ARCHITECTURAL CONSULTANTS
2121 Mlntiel Read, San Marcos, CA 92069 Phone: (760)839-7302 lax: (760)480-7477
FIGURE
3
E:IFORMS\1 FRM\2000\MASTER -FIG.wpd
PROJECT NAME BAGNALL RESIDENCE LOG OF BORING No. 8=.l PROJECT NUMBER 053776 I
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LOCATION 5029 TIERRA DEL ORO; CARLSBAD, CA SHEET 1 OF 1
DATE
DRILLED
LOGGED BY
DIAMETER
OF BORING
lYPE OF
SAMPLER(S)
~1 ~ ~ ffi o..m
C ,::_ ~ ~i
f---
--
-
--/2 1
-5 ----J 2
--
--
-10
NOVEMBER 2, 2005 DRIWNG METHOD TOTAL DEPTH
AND TYPE OF RIG HOLLOW STEM AUGER DRILLED (feet)
*~
~::) ..;;JO mu
4,4,2
7,9, 15
12,13,
ERIN RIST BACKFILLED/CONVERTED TO WELL ON(date) APPROX SURFACE
BACKFILLED W/ CUTTINGS 11-2-05 ELEVATION (feet)
8-INCH GROUNDWATER FIRST COMPLETION
LEVEL (feet B6S) NONE NONE
~SPT lYPE OF SAFETY WEIGHT (lbs) DROP (in.)
~ CALIFORNIA HAMMER 140 30
t:1
U>z
6
24
Q
; § MATERIAL DESCRIPTION AND NOTES
C)
. •• · '. ••• TOPSOIL/FILL -SILTY SANDS (SM), dark brown to light brown, dry to
·.• > .. ... slightly moist
.. ,•,
>? :':. :: .. ; SANDSTONE (SW-SM), rust brown, medium dense, slightly silty sands
•I•• ,; "; •• ~' •. ·,:" '•
;~\ ~·-:::-SANDSTONE (SW-SM), rust brown, slightly moist, weathered, slightly silty
.... / ._:_, sandstone.
... .-:·· ••
•, ··••' ••,• :\' ..
~-:-.. ~/ :--~:.·
I ... -i --
3 18 31 :: .. ~ \ t:: SANDSTONE (SW-SM), rust brown to tan, slightly moist to moist, slightly
• :: .. '.. • :.: silty sandstone.
:. ::>:•:, ;-~ SANDSTONE (SW-SM), rust brown to tan, moist, slightly silty sandstone. ......... : ~ :. -I --.. : : •: . ~ .; .
-15 -----------'-+--------------------------;
... -
J 14,23, 49 • ·.·.:.::; -:' CEMENTEJ SANDSTONE (SW-SM), white to tan, moist, dense to very dens~, I --..J-ilo.__
4
_!---2_6 ---1----l·; :,( { :> :ti~ /o~b1;
0
( gravel,
--
--
........ .... ·.·• .... . ·, :~
;i,}t
i-20
... -I END OF DRIWNG AT 2O.O'
NO GROUNDWATER. NO CAVING.
BACKFILLED WITH CUTTINGS .
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... -
--
--
-25
II ENGINEERING
. DESIGN GROUP
2121 MONTIEL ROAD
SAN MARCOS, CA 92069
{780) 839-7302
PAX (760) 480-7477
ADDmONAL NOTES / COMMENTS:
BORING LOCATED @ TOP OF SLOPE, MIDDLE OF REAR YARD
NOTES: * FOR 6n ** UNCORRECTED SPT
20.0
32.5
PROJECT NAME BAGNALL RESIDENCE LOG OF BORING No. a::2 PROJECT NUMBER 053776 I
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LOCATION 5029 TIERRA DEL ORO; CARLSBAD, CA SHEEf 1 OF 1
DATE
DRILLED
LOGGED BY
DIAMETER
OF BORING
TYPE OF
SAMPLER(S)
~---~ ~ ffi
.! a. a.m ~ ~i c-
--
--
-
-1
NOVEMBER 2, 2005 DRIWNG METHOD TOTAL DEPTH
AND lYPE OF RIG HOLLOW STEM AUGER DRILLED (feet)
ERIN RIST BACKFILLED/CONVERTED TO WELL ON(date) APPROX SURFACE
BACKFILLED W/ CUTTINGS 11-2-05 ELEVATION (feet)
8-INCH GROUNDWATER FIRST COMPLETION
LEVEL (feet BGS) NONE NONE
~SPT lYPE OF SAFElY WEIGHT (lbs) DROP (in.)
e'.:i CALIFORNIA HAMMER 140 30
*~ li:I ~:::, Cl) z ~o m c.,
c.,
I§ MATERIAL DESCRIPTION AND NOTES
c.,
_ , .. TOPSOIL/FILL -SILTY SANDS (SM), dark brown to light brown, dry to
• • •. . slightly moist, loose to medium dense
4,7,9 16
-:· •: ••.
.. ..
I-
-Ai ' .
, ..... :_.-· :.:'." SANDSTONE (SW-SM), rust brown, moist, dense, slightly silty sands
·. :} • ~:-.'·•:::
.......... 1----l---l------l_ .. 7 ' . ', ••
5 -..
--
-
i--10
t-I -
-I -
.,. : .. ~:. ~ ::: .
--------1, :-·',·· ·:~
-:/4 2 7,6,6
-
-
. .. .
,•~ ' •J. : • , ..
•• -;_·> ..... , •• . . . .. ~· ·, ,· ... ; •·, •.
,: ,.: ·:.:
-& 3 6 8 11 :· °',: .:''. .·: SANDSTONE (SW-SM), brown to tan, moist, dense to very dense, slightly _____ • _• __ 1_9 _/; . .-;-... , silty sands
-:::t<:.·~-
-,·,.:·· ....
•'. 'l : /i;~. ,,•:. ·, -·:;t;,.--:: .• :
i-15 -
-
-
15,25, 60 • • : ::-·:.: CEMENTED SANDSTONE (SW-SM), white, moist, very dense, coarse sands
20.0
37.0
I -_ ••Jl 4
35 -~ ~· .. . i--20 _,.....,:,"+-'' ---i----+-----l .................. 1-------------------------+---t I END OF DRIWNG AT 20.0'
,... -NO GROUNDWATER. NO CAVING.
_ _ BACKFILLED WITH CUTTINGS.
I'""
-
I--I -25
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II ENGINEERING
DESIGN GROUP
2121 MONTIEL ROAD
SAN MARCOS, CA 92069
. (780) 839-7302
ll'AX (780) 480-7477
ADDffiONAL NOTES / COMMENTS:
BORING LOCATED @ FRONT IN PLANTER
MQIES,; * FOR 6" ** UNCORRECTED SPT
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APPENDIX A
REFERENCES
1. California Department of Conservation, Division of Mines and Geology, Fault Rupture
Zones in California, Special Publication 42, Revised 1990.
2. County of San Diego Ortho-Topographic Map 350-1665, dated September 17.
3. Engineering Design Group, unpublished in house data.
4. Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from Earthquakes in
California Division of Mines and Geology, Map Sheet 23.
5. Lee, L.J., 1977, Potential foundation problems associated with earthquakes in San
Diego, in Abbott, P.L. and Victoria, J.K., eds. Geologic Hazards in San Diego,
Earthquakes, Landslides, and Floods: San Diego Society of Natural History John Porter
Dexter Memorial Publication.
6. Lee, L. Pinckney, C., and Bemis, C., 1976, Sea bluff erosion: American Society of Civil
Engineers, National Water Resources and Ocean Engineering Convention Preprint No.
2708.
7. Ploessel, M.R. and Slossan, J.E., 1974 Repeatable High Ground Acceleration from
Earthquakes: California Geology, Vol. 27, No. 9, P. 195-199
8. State of California, Fault Map of California, Map No. 1, Dated 1975.
9. State of California, Geo:ogic Map of California, Map No. 1, Dated 1977.
10. U.S. Army Corps of Engineers, 1985, Coast of California Sotrm and Tidal Waves Study,
Shoreline Movement Data Report, Portuguese Point to Mexican Border, dated
December
11. U.S. Army Corps of Engineers, 1985, Coast of California Sotrm and Tidal Waves Study,
Coastal Cliff Sediments, San Diego Region (CCSTWS 87-2), dated June.
12. Van Dorn, W.G., 1979 Theoretical aspects of tsunamis along the San Diego coastline, in
Abbott, P.L. and Elliott, W.J., Earthquakes and Other Perils: Geological Society of
America field trip guidebook.
13. Various Aerial Photographs
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I APPENDIX -8-
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******************************************
* X S TAB L *
* *
* Slope Stability Analysis *
* using the *
* Method of Slices *
* *
* Copyright (C) 1992 -96 *
* Interactive Software Designs, Inc. *
* Moscow, ID 83843, U.S.A. *
* *
* All Rights Reserved *
* *
* Ver. 5.200 96 -1524 *
******************************************
Problem Description BAGNALL -NON CIRCULAR -PSTATIC
-----------------------------
SEGMENT BOUNDARY COORDINATES
-----------------------------
10 SURFACE boundary segments
Segment x-left y-left x-right
No. (ft) (ft) (ft)
1 . 0 10.0 53.0
2 53.0 10.0 68.0
3 68.0 20.0 90.0
4 90.0 25.0 107.0
5 107.0 30.0 136.0
6 135.0 40.0 158.0
7 158.0 40.0 158.2
8 158.2 44.0 164.0
9 164.0 47.0 190.0
10 190.0 47.0 229.0
1 SUBSURFACE boundary segments
Segment
No.
1
Bagnall Residence
x-left
(ft)
90.0
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
y-left
(ft)
25.0
x-right
(ft)
229.0
y-right
(ft)
10.0
20.0
25.0
30.0
40.0
40.0
44.0
47.0
47.0
47.0
y-right
(ft)
26.0
Soil Unit
Below Segment
2
2
2
1
l
1
1
1
1
1
Soil Unit
Below Segment
2
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ISOTROPIC Soil Parameters
2 Soil unit(s) specified
Soil
Unit
No.
Unit Weight
Moist Sat.
Cohesion
Intercept
(psf)
Friction
Angle
(deg)
Pore Pressure
Parameter Constant
1
2
(pcf) (pcf)
120.0
120.0
125.0
125.0
100.0
400.0
35.00
38.00
1 Water surface(s) have been specified
Unit weight of water= 62 .40 (pcf)
Ru (psf)
.000
.000
Water Surface No. 1 specified by 3 coordinate points
**********************************
PHREATIC SURFACE,
**********************************
Point x-water y-water
No. (ft) (ft)
1 53.00 10.00
2 95.00 25.00
3 231.00 25.00
A horizontal earthquake loading coefficient
of .150 has been assigned
A vertical earthquake loading coefficient
of .000 has been assigned
BOUNDARY LOADS
1 load(s) specified
. 0
. 0
Load
No.
x-left
(ft)
x-right
(ft)
Intensity
(psf)
Direction
(deg)
1 190.0 230.0 1000.0 . 0
NOTE -Intensity is specified as a uniformly distributed
Bagnall Residence
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
Water
Surface
No.
1
1
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force acting on a HORIZONTALLY projected surface.
A critical failure surface searching method, using a random
technique for generating IRREGULAR surfaces has been specified.
100 trial surfaces will be generated and analyzed.
10 Surfaces initiate from each of
along the ground surface between x =
and x
Each surface terminates between
and
X
X
10 points equally spaced
40.0 ft
130.0 ft
140.0 ft
210.0 ft
Unless further limitations were imposed, the minimum elevation
at which a surface extends is y = 1.0 ft
8.0 ft line segments define each trial failure surface.
ANGULAR RESTRICTIONS
The first segment of each failure surface will be inclined
within the angular range defined by:
Lower angular limit .
Upper angular limit .-
-45.0 degrees
(slope angle -5.0) degrees
Factors of safety have been c..-,lculated by the
* * * * * SIMPLIFIED JANBU METHOD * * * * *
The 10 most critical of all the failure surfaces examined
are displayed below -the most critical first
Failure surface No. 1 specified by 15 coordinate points
Bagnall Residence
Point
No.
1
2
3
4
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
x-surf
(ft)
50.00
56.51
64.45
72.42
y-surf
(ft)
10.00
5.35
4.33
4.95
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5 80.42 5.06
6 87.90 7.92
7 95.80 9.14
8 103.74 10.13
9 111.34 12.62
10 117.66 17.52
11 124.29 22.00
12 129.89 27.72
13 135.93 32.97
14 142.65 37.31
15 144.48 40.00
** Corrected JANBU FOS = 1.840 ** (Fo factor 1. 063)
Failure surface No. 2 specified by 16 coordinate points
Point x-surf y-surf
No. (ft) (ft)
1 50.00 10.00
2 56.45 5.27
3 63.35 1.22
4 71. 35 1.24
5 79.34 1. 61
6 87.32 2.16
7 95.32 2.30
8 103.25 1.19
9 110. 62 4.30
10 118.24 6.72
11 125.53 10.03
12 131. 49 15.36
13 136.73 21.41
14 140. 96 28.20
15 144.89 35.16
16 146.51 40.00
** Corrected JANBU FOS J. 904 ** (Fe factcr 1.0RO)
Failure surface No. 3 specified by 18 coordinate points
Point x-surf y-surf
No. (ft) (ft)
1 50.00 10.00
2 55. 72 4.41
3 63.72 4.05
4 71.69 3.45
5 79.67 2.81
6 87.61 1.85
7 95.28 4.12
8 103.04 6.06
9 110.09 9.84
10 117.70 12.30
11 125.07 15.41
12 132.90 17.07
Bagnall Residence
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
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13 140.24 20.25
14 147.12 24.34
15 152.62 30.15
16 158.81 35.22
17 162.72 42.20
18 166.56 47.00
** Corrected JANBU FOS 1.916 ** (Fo factor
Failure surface No. 4 specified by 16 coordinate points
Point x-surf y-surf
No. (ft) (ft)
1 50.00 10.00
2 56.28 5.05
3 64 .15 3. 61
4 72.12 2.86
5 80.01 1.55
6 88.00 1. 91
7 94.50 -6 .57
8 101. 66 10.15
9 108.15 14. 83
10 113.66 20.62
11 120.35 25.01
12 126.93 29.56
13 134.04 33.23
14 141. 80 35.18
15 149.42 37.62
16 151.58 40.00
** Corrected JANBU FOS = 1.943 ** (Fo factor
Failure surface No. 5 specified by 16 coordinate points
Point x-surf y-surf
No. (ft) (L:)
1 40.0G 10.00
2 46. 77 5.7-i
3 54.32 3.09
4 62.30 2.54
5 70.28 1. 96
6 77 .35 5.70
7 84.36 9.57
8 92 .14 11.41
9 100.12 11.97
10 108.03 10. 78
11 115.67 13.17
12 121. 42 18.73
13 128.45 22.54
14 134.04 28.27
15 140. 31 33.24
16 141. 70 40.00
Bagnall Residence
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
1. 063)
1. 066)
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** Corrected JANBU FOS 2.007 ** (Fo factor
Failure surface No. 6 specified by 17 coordinate points
Point x-surf y-surf
No. (ft) (ft)
1 40.00 10.00
2 46.60 5.48
3 54.48 4 .11
4 62.15 1.85
5 70.15 1. 64
6 78.01 3.12
7 85.77 5.09
8 93.60 6.72
9 101. 60 6.84
10 109.58 7.36
11 117.50 6.20
12 124.09 10.73
13 129.61 16.53
14 135.49 21.95
15 138.51 29.36
16 140.83 37.01
17 142.05 40.00
** Corrected JANBU FOS 2.024 ** iFo factor
Failure surface No. 7 specified by 22 coordinate points
Point x-surf y-surf
No. (ft) (ft)
1 40.00 10.00
2 45.81 4.51
3 53.32 1.74
4. 61.32 l.57
5 69.31 1.16
6 77.31 1. 20
7 85.31 1.03
8 92.54 4.45
9 100.09 7.08
10 107.87 8.98
11 115.40 11.67
12 123.14 13.69
13 131. 03 15.04
14 138.93 16.26
15 146.92 16.74
16 154. 91 16.55
17 161. 26 21.42
18 167.90 25.89
19 174.66 30.17
20 179.20 36.76
21 183.45 43.54
22 185 .11 47.00
Bagnall Residence
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
1. 066)
1.080)
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** Corrected JANBU FOS = 2.049 ** (Fo factor 1.058)
Failure surface No. 8 specified by 19 coordinate points
Point x-surf y-surf
No. (ft) (ft)
1 50.00 10.00
2 56.84 5.85
3 64.43 3.32
4 72.29 1. 83
5 80.06 3.75
6 87.84 5.60
7 95.79 6.44
8 103.55 8.41
9 110.98 11.37
10 118.77 13.17
11 126.69 14. 31
12 134.26 16.90
13 141.99 18.94
14 149.99 19.32
15 157.08 23.01
16 163.23 28.13
17 165.73 35.73
18 166.41 43.70
19 166.78 47.00
** Corrected JANBU FOS 2.058 ** (Fo factor =
Failure surface No. 9 specified by 16 coordinate points
Point x-surf y-surf
No. (ft) (ft)
1 50.00 10.00
2 55. ·3 4.36
3 63.59 3.17
4 71.::'9 1.00
5 79.28 1. 37
6 87.28 1.32
7 95.28 1.41
8 103.26 1. 93
9 111. 22 2.76
10 118.91 4.95
11 126.52 7.43
12 133.00 12 .12
13 136.26 19.42
14 140.05 26.47
15 140.64 34.45
16 141. 79 40.00
** Corrected JANBU FOS 2.068 ** (Fo factor =
Failure surface No.10 specified by 18 coordinate points
Bagnall Residence
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
1.066)
1.084)
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Point x-surf y-surf
No. (ft) (ft)
1 40.00 10.00
2 46.28 5.04
3 54.05 3.12
4 61. 77 1.04
5 69.29 3.75
6 76.62 6.96
7 84.28 9.26
8 91.53 12.65
9 98.77 16.07
10 106.40 18.47
11 114.28 19.83
12 122.04 21. 76
13 130.00 22.59
14 136.95 26.56
15 '.1.43.55 31. 07
16 150.70 34.67
17 156.68 39.98
18 156.71 40.00
** Corrected JANBU FOS 2.093 ** (Fo factor 1.049)
The following is a summary of the TEN most critical surfaces
Problem Description: BAGNALL -NON CIRCULAR -PSTATIC
Modified
JANBU FOS
1. 1. 840
2. 1. 904
3. 1. 916
4. 1.943
5. 2.007
6. 2.J24
7. 2.049
8. 2.058
9. 2.068
10. 2. 093
Bagnall Residence
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
Correction Initial
Factor x-coord
(ft)
1.063 50.00
1.080 50.00
1. 063 50.00
1. 066 50.00
1.066 40.0C
1.080 40.00
1. 058 40.00
1. 066 SO.JO
1.084 5C.00
1.049 40.00
* * * END OF FILE *
Terminal Available
x-coord Strength
(ft) (lb)
144.48 1.149E+05
146.51 1.637E+05
166.56 1. 726E+05
151. 58 1.166E+05
141.7( 1 317E+05
142.05 1.563I::+'J5
185.11 2. 436E-:-05
166.78 1.907E+05
141. 79 1.667E+05
156. 71 1. 341E+05
* *
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BAGN-NON 12-18-u 15:33
BAGNALL -NON CIRCULAR -PSTATIC
150
120
........
ai 90
(l) -.......,
(/)
X
<( 60
I >-
30
0
0
Bagnall Residence
30
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
60 90 120 150
X-AXIS (feet)
___ w1
180 210 240
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BAGN-N0N 12-18-u 15:33
BAGNALL -NON CIRCULAR -PSTATIC
150 100 surfaces have been generated for this analysis
120
-ai 90 Q) --(/1
X
<( 60 I >-
30
0
0
Bagnall Residence
30
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
60 90 120 150 180
X-AXIS (feet)
210 240
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BAGN-CIR 12-18-•• 16:34
BAGNALL -CIRCULAR -PSTATIC
150 10 most critical surfaces, MINIMUM JAN BU FOS = 1.829
120
-a> 90 Q) -'-"
(/)
X
<C 60 I >-
30
0
0
Bagnall Residence
30
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 1 of 2
60 90 120 150 180 210
X-AXIS (feet)
240
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BAGN-NON 12-18-o 15:33
BAGNALL -NON CIRCULAR -PSTATIC
150 10 most critical surfaces, MINIMUM JAN BU FOS =
u,
X
120
<( 60
I >-
30
0
0
Bagnall Residence
30
5029 Tierra Del Oro, Carlsbad, CA
Slope Stability Analysis: Run 2 of 2
60 90 120 150 180
X-AXIS {feet)
1.840
___ w1
210 240
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I APPENDIX -C-
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MINIMUM RETAINING WALL WATERPROOFING
& DRAINAGE DETAIL
-FINAL WATERPROOF'.1✓G SPECIFICATIONS & Dt:TAILS TO BE. PROVIDED
BY PROJECT ARCHITECT
• TOP _OF RET AJNING WALL
• <C
MASTIC TO BE APPLIED TO TOP Of' WALL
~--MASTIC TYPE WATER PROOFING (HLM 5000 OR EQUIV)
INSTALLED PER MANUFACTURES
SPECIFICATIONS & PROTECTED WITH
SACl<ER BOARD (ABOVE MIRA0RAIN) MASTIC NOT TO BE
EXPOSED TO SUNLIGHT
SOIL BACKFILL. COMPACTED TO 907.
RELATIVE COMPACTION P£R REFERENCE #1
z .... ~ = 1_· _. : !~-• l : :_· 11 !
,., 1 : i==i 1 !==I i :== ~ ~ _, ·-~-'-·"i""":7-' ·---1 ,-, / \j.ROPOSED SLOPE BACKCUT
ER OSHA STANDARDS -;=----r::;;lr:-:::-1::;;:,_:::;_ .== .. ==i1 :==! -, ' ·-=-
NO MIRAORAIN (top)----,Q-.P::;-! ! .-
RETAINING WALL
MIRAORAIN MEMSRAN€
INSTAU.EO PER MANUF' ACT\JRES
SPECIFJCA TlONS OVER MASTIC
WA. 'TERPROOFING -HLM !5000
OR E:QIJIVAI.ENT
PROJECT NAME
PROJECT ADDRESS
JOB NUMBER
, •.••. , AREA ORAi
:} ~-/-' SYSTEM
OR PER AL TERNA llVE SLOPING
PLAN, OR PER APPROVED SHORING PLAN
·-~: :·~: .. ••
t•,::. _____ _,,,,_ __ FILTER FABRIC ENVELOPE"
..... (MIRAFI 140N' OR •
APPROVED EQUIVALENT) 12" MIN. LAP .
------J/4ff -1 1/2w CLEAN
GRAVEL
:;;,,..,.-i-.-----,------4-"X4" (45<1) CONCRETE CANT
0 FOOTING/WALL CONNECTION
(UNDER WATER PROOFING)
-----coMPETENT BEDROCK OR FILL MATERIAL
AS EVALUATED BY THE GEOTECHNICAL
CONSULTANT
SCALE: 1" = 1' -0"
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CML, STRUCTURAL & ARCHITECTURAL CONSULTANTS
2121 Montiel Road, San Marcos, CA 92069 Phone: (760)839-7302 Fax: (760)480.7 477
FIGURE
\\Mainlf1le on main\FORMS\1 FRM\2000\MASTER -FIG.wpd