HomeMy WebLinkAboutCT 81-35; Pointe San Malo; Soils Report; 1988-07-18I q ikn LEIGHTON AND ASSOCIATES, INC. -‘Y ZM--’
Geotedmical and Environmental Engineering Consultants
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PRELIMINARY GEOTECHNICAL INVESTIGATION, BLUFF PROTECTION, "THE BEACH" SUBDIVISION, CARLSBAD, CALIFORNIA
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July 18, 1988 (Revised August 11, 1989)
Project No. 8880700-01
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Prepared for:
MR. DAVID COPLEY 2335 Rue Des Chadeaux Carlsbad, California 92008
5421 AVENIDA ENCINAS, SUITE C, CARLSBAD, CALIFORNIA 92008 (619) 931-9953
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July 18, 1988
(Revised August 11, 1989)
Project No. 8880700-01
To: Mr. David Copley 2335 Rue Des Chadeaux Carlsbad, California 92008
Subject: Preliminary Geotechnical Investi ation, Bluff Protection, "The Beach" Subdivision, Carlsbad, 9. Ca ifornia
In accordance with your written authorization dated May 18, 1988, we have conducted a preliminary geotechnical investigation of the subject site. This report presents a summary of our investigation and provides conclusions and recommendations relative to bluff protection construction at the site.
If you have any questions regarding our report, please do not hesitate to contact this office. We appreciate this opportunity to be of service.
Respectfully submitted,
LEIGHTON AND ASSOCIATES, INC. \riultiRLb
Michael R. Stewart, CEG 1349 (Exp. 6/30/90) Chief Engineering Geologist
Stan Helenschmidt, RCE 36570 (Exp. 6/30/92) Chief Engineer/Manager
RLW/MRS/SRH/bje
Distribution: (1) Addressee (5) Moffatt and Nichol Engineers Attention: Mr. Bob Nathan
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5421 AVENIDA ENCINAS, SUITE C, CARLSBAD, CALIFORNIA 92008 (619) 931-9953
FAX (619) 931-9326
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TABLE OF CONTENTS
Section
1.0
2.0
3.0
4.0
5.0
6.0
7.0
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INTRODUCTION ....................................................
SITE DESCRIPTION AND PROPOSED CONSTRUCTION ......................
2.1 Site Description ...........................................
2.2 Proposed Construction ......................................
SUBSURFACE EXPLORATION AND LABORATORY TESTING ...................
GEOTECHNICAL CONDITIONS .........................................
4.1 Regional Geology ........................................... 4.2 Site Geology ...............................................
4.3 Geologic Structure .........................................
4.4 Ground Water Conditions .................................... 4.5 Bluff Erosion ..............................................
FAULTING, SEISMICITY AND LIQUEFACTION ...........................
5.1 Faulting ...................................................
5.2 Seismicity ................................................. 5.3 Liquefaction ...............................................
CONCLUSIONS .....................................................
RECOMMENDATIONS .................................................
7.1 Slope Stability ............................................ 7.2 ;;;;E;uction Considerations for Bluff/Shore Protection ...... ............... .... ............ ................
7.2.1 Excavation and Construction Dewatering ..............
7.3 Rock Revetment Design Considerations .......................
7.3.1 Revetment Backcut ...................................
7.3.2 Filter Fabric .......................................
7.4 Retaining Wall Design Considerations .......................
7.4.1 Foundation Design ................................... 7.4.2 Lateral Resistance ..................................
7.4.3 Lateral Earth Pressures ............................. 7.4.4 Drainage ............................................
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TABLE OF CONTENTS (Continued)
7.5 Backfill ................................................... 14 7.6 Type of Cement for Construction ............................ 7.7 Corrosivity ................................................ :: 7.8 Construction Observation ................................... 15
Aooendices
Appendix A - References Appendix B - Boring Logs Appendix C - Summary of Laboratory Test Results Appendix D - Slope Stability Analysis
LIST OF TABLES AND ILLUSTRATIONS
Table 1 - Seismic Paramters for Active Faults Rear of Text
Fiqures
Figure 1 - Site Location Map Figure 2 - Fault Location Map Figure 3 - Geologic Cross-Section A-A' Figure 4 - Geologic Cross-Section B-B'
Plate 1 - Geotechnical Map
Rear of Text Rear of Text Rear of Text Rear of Text
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1.0 INTRODUCTION -
- This report presents the results of our geotechnical investigation at the subject site. The purpose of this investigation was to identify and evaluate the geotechnical conditions present on the site and to provide conclusions and geotechnical recommendations regarding the proposed construction of the bluff improvements. Our scope of service included:
Review of available pertinent, published and unpublished geotechnical literature and maps, and aerial photographs pertaining to the subject site (Appendix A).
Field reconnaissance of the existing onsite geotechnical conditions.
Subsurface exploration consisting of the excavation, logging and sampling of four small-diameter borings. The logs of the borings are presented in Appendix B.
Laboratory testing of representative, undisturbed and bulk soil samples obtained from our subsurface exploration program (Appendix C).
Compilation and analysis of the geotechnical data obtained from our field investigation and laboratory testing program.
Preparation of this report presenting our findings, conclusions and preliminary geotechnical recommendations with respect to the proposed site bluff-protection construction.
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2.0 SITE DESCRIPTION AND PROPOSED CONSTRUCTION
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2.1 Site Descriotion
The subject bluff is located along the western edge of "The Beach" subdivision in the City of Carlsbad, along the south side of Buena Vista Lagoon (Figure 1). The existing condominium development ("The Beach" subdivision) consists of 14 units located atop and easterly of the
bluff. Construction of the development was completed in June 1985. An existing 5- to 6-foot high stucco retaining wall is located along the top of the bluff with associated subdrain outlets near the toe of the wall. A stairway access leads down to the beach at the north portion of the subdivision. A public beach access stairway and a storm drain easement (and outlet structure) are located at the southern end of the
g roperty. Vegetation on the bluff is moderate, with local sparse to arren areas.
Topographically, the site consists of a moderate to gently sloping westerly facing 15- to 20-foot high bluff. The majority of the bluff face descends at an approximate 2:l (horizontal to vertical) or flatter inclination seaward with a 2- to IO-foot high cliff at the base of the bluff. Inclination of the sea cliff ranges from approximately l/2:1 (horizontal to vertical) to vertical and overhanging locally. Below this cliff is a gently sloping and irregular, lOO- to 120-foot wide, wave-cut terrace or bedrock abrasion platform that is 0 to 10 feet above mean sea level. The regional and site-specific topographic parameters are illustrated on Figures 1, 3, and 4, and Plate 1, respectively. Review of available topographic maps (Appendix A), indicates that elevations on the site range from mean sea level near the shoreline to approximately 25 feet along the top of the bluff. Surface drainage appears to follow the present slope gradients seaward. Erosion on the upper, more gently sloping bluff face is slight to moderate. Erosion at the bluff toe (at the edge of the bluff) is generally more severe.
Based on conversation with Mr. David Copley, we understand that the vertical cliff at the base of the bluff apparently is the result of severe erosion which occurred rapidly during recent periods of high surf and storms. This recent rapid retreat of the bluff face has rais: concerns of possible future, more severe periods of bluff retreat. order to minimize the potential of future damage related to continued
bluff retreat, some type of slope protection is desirable.
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2.2 prooosed Construction
Based on our conversation with Mr, Bob Nathan of Moffatt and Nicol Engineers, we understand site-specific plans for bluff protection have not been prepared. However, we understand proposed mitigative measures will consist of constructing a reinforced sea wall or a stone revetment along the toe of the bluff to provide protection against further erosion caused by wave attack. Detailed structural information was not
available at the time of this report. Based on our evaluation of the geotechnical conditions of the bluff and beach areas, we havefErided preliminary earthwork, foundation and design criteria the construction of the bluff/shore protection improvements.
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3.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING
Our subsurface exploration program consisted of the excavation of four small- diameter borings to a maximum depth of 16 feet. The purpose of these excavations was to obtain data on the physical characteristics of the subsurface soils. More specifically, the borings allowed evaluation and measurement of the stratigraphic horizons pertinent to bluff slope stability.
The exploratory borings were logged and sampled by a geologist from our firm. Representative bulk and undisturbed (drive cylinders) samples were obtained for laboratory testing. The approximate locations of the borings are shown on Plate 1 (in pocket). Logs of the borings are presented in Appendix 8. Subsequent to logging and sampling, the borings were backfilled.
Laboratory testing was performed on representative samples to evaluate th; density, strength and chemical characteristics of the subsurface soils. discussion of the laboratory tests performed and a summary of laboratory test results are presented in Appendix C. In-situ moisture and density results are provided on the boring logs (Appendix B).
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4.0 GEOTECHNICAL CONDITIONS
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4.1 &gional Geoloqy
The subject site is situated in the coastal section of the Peninsular
Range Province, a California geomorphic province with a long and active history throughout southern California. Through the last 54 million years, the area known as the "San Diego Embayment" has undergone several episodes of marine inundation and subsequent marine regression. This has resulted in a thick sequence of marine and non-marine sediments deposited on rocks of the southern California batholith with relatively minor tectonic uplift of the area.
4.2 Site Geolooy
The lowermost part of the cliff (at south end of site) and the cobble- mantled wave-cut terrace near the shoreline have been cut into the Eocene-aged Santiago Formation (Map Symbol - Tsa). As observed in the boring samples, this sedimentary unit consists of an olive-gray, hard, clayey siltstone to a dense, clayey, fine-grained sandstone. This unit was encountered at a de th in our borings. of approximately 15 feet below the bluff face A 7 ocalized exposure of gray sandstone was also observed near the base of the sea cliff at the southern end of the property (Figure 4). The onsite Santiago Formation was noted as being slightly cemented and relatively resistant to wave erosion.
The bluff and majority of the cliff consists of Pleistocene marine terrace deposits (Map Symbol - Qt). These terrace deposits represent an ancient wave-cut platform and associated near-shore deposits which have been uplifted in relation to the current sea level. The bluff face and t.i.dstop of the sea cliff are mantled by a thin veneer of loose, silty The terrace deposits, as exposed on the sea cliff face, were noted' as consisting of relatively massive, moderately friable, light brown to light red-brown, silty, fine- to coarse-grained sand with scattered to locally abundant gravel and cobbles (to six inches in diameter). Scattered shell fragments were also noted on the cliff face. ;",ua, terrace deposits are slightly cemented when exposed on the cliff As encountered in our borings (Appendix B), the terrace deposits predominantly consist of light brown to medium red-brown and orange- brown, friable, dry to damp, loose to medium dense, silty, fine- to medium-grained sand and light gray to off-white, damp, loose to dense, quartz-rich, fine- to coarse-grained sand with local to abundant gravel and cobbles. Based on our geologic reconnaissance and subsurface exploration, the thickness of this deposit is anticipated to range from approximately 8 to 15 feet at the bluff face.
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Recent cobbles and beach sands (Map Symbol - Qb) mantle the wave-cut bedrock platform along the shoreline. Beach sand is every sparse and confined to localized areas near the shoreline. These recent marine
deposits predominantly consist of abundant beach cobbles and to lesser
amounts of unconsolidated, loose, silty, fine- to medium-grained sands.
4.3 Geolooic Structure
Observations made during our investigation and experience with similar units on nearby sites indicate that the Pleistocene terrace deposits and Tertiary Santiago Formation are generally massive in this area with no significant geologic structure. Pertinent geotechnical literature (Appendix A) indicates that the sedimentary soils are generally flat- lying to gently dipping. No major folding of the sedimentary units is known or expected to exist at the site. Some discontinuous, poorly
developed fractures were noted locally within the terrace deposits exposed in the cliff. The onsite fracturing predominantly consists of exfoliation-type fracturin cliff and dips near-vertica 9 which generally trends sub-parallel to the to vertical.
4.4 Ground Water Conditions
No indication of ground water was evident at the time of our investigation. The static ground water table is anticipated to roughly correlate to mean sea level. However, it should be noted that a perched ground water condition may develop at the contact between the bedrock and overlying Pleistocene terrace deposit for short periods following storm activity or artificial recharge due to irrigation. This stored ground water may be evident as seeps where water bearing fractures are exposed at the surface or daylighted in excavations. Seasonal fluctuations in rainfall, variations in ground surface topography, and subsurface conditions may significantly affect surface and ground water levels.
4.5 Bluff Erosion
Coastal bluffs and cliffs in the area are under the constant influence ;Lr;;;sional processes caused by the actions of sea wave, rain, and wind Evidence of recent sloughing and erosion was observed during our site visit. The storm drain outlet structure near the southern end of the property has been exposed and approximately 5 to 6 feet of storm drain pipe has been undermined and exposed. Based on available literature and comparison of aerial photographs (Appendix A), erosion of the bluff toe-cliff has been locally severe. Storm related erosion appears to have been the main contributing factor to landward retreat of the bluff. In general, the toe or cliff-forming portion of the bluff is
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subjected to erosion by hi h causing loosening and tides and wave attack, undermining the toe, s oughing of the overlying terrace deposits and 9 subsequent collapse seaward. Through time this process is repeated and progressive failures of the bluff result in bluff retreat landward.
Based on our review of aerial photographs and available literature,
beach erosion at the site has been severe. It ap ears that beach sand has been subject to changes in thickness and ! supp y due in part to recent storm activity and construction of the Oceanside Harbor to the north. Since the construction of the harbor, sand replenishment has apparently been altered due to fluctuations in long shore transport.
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5.0 FAULTING, SEISMICITY AND LIOUEFACTION
5.1 Faultinq
A review of available geologic literature and aerial photos pertaining to the subject site indicates that there are no known active faults crossing the property. Newport-Inglewood, The nearest active regional .faults are the located offshore approximately 19 ~;~;;e;ort~;o;~ the site and the Coronado Banks fault zone, approximately 20 miles southwest of the site. Figure 2 illustrates the site location in relationship to known major faults in the San Diego region. Included on Figure 2 are the approximate epicentral area magnitude of earthquakes recorded during the period of 1769 to 1973.
5.2 SeismicitY
The subject site can be considered to be within a seismically active region as can all of southern California. The seismic hazard most likely to impact the subject site is ground shakin
earthquake on one of the major active regional 9 following a large
fau ts. Table 1 (rear of text) indicates potential seismic events that could be produced by maximum probable earthquakes. A maximum probable earthquake is the maximum expectable earthquake produced from a causative fault durin a loo-year interval. 9 Site-specific seismic t;;;mntersR;;;:;ed in Tab e 1 are the distances to the causative earthquake magnitudes, expected peak/repeatable high groind accelerations (RHGA) and estimated period and duration of ground shaking.
As indicated in Table 1, the Elsinore fault is considered to have the most significant effect at the site from a design standpoint. A mximum probable earthquake of Richter magnitude of 7.3 on the Elsinore fault could produce a peak horizontal bedrock acceleration of approximtely 0.249. These seismic parameters should be considered by the structural engineer in the design of structures and improvements.
5.3 Liauefaction
Liquefaction and dynamic settlement of soils can be caused by strong vibratory motion due to earthquakes. Both research and historical data indicate that loose, saturated, granular soils are susceptible to liquefaction and dynamic settlement, while the stability of silty clays
and clays is not adversely affected by vibratory motion. Liquefaction is typified by a total loss of shear strength in the affected soil layer, thereby causing the soil to flow as a liquid. This effect may be manifested by excessive settlements and sand boils at the ground surface. The onsite terrace deposits are not considered liquefiable due to their unsaturated condition. considered liquefiable due to its high The Santiago Formation is ;I; density characteristics. onsite beach sands should be considered highly liquefiable. refer to Section 7.2 for recommendations to help mitigate Pl;ea;;
condition.
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6.0 CONCLUSIONS
Based on the results of our preliminary geotechnical investigation of the site, it is our opinion that the proposed construction is feasible from a geotechnical standpoint, provided the following conclusions and recommendations are incorporated into the design plans and specifications.
The following is a summary of the main geotechnical factors for the subject site.
$i;;tefaults are not known to exist on or in the immediate vicinity of
The maximum anticipated bedrock acceleration on the site is estimated to be 0.249 based on a maximum probable earthquake of Richter magnitude 7.3 on the active Elsinore fault.
Based on available literature, comparison of aerial photographs and our observations made during the investigation, the toe of the bluff is subjected to storm wave activity. cliff bluff toe,
This causes undermining of the sea initiating failures of the terrace sand deposits. Therefore, the bluff is retreating in response to the wave action.
Historically, erosion of bluff areas located along the northern San Diego County coastline is site-specific, episodic and generally related to climatic changes. Therefore, rates of erosion for the bluff cannot be accurately determined.
Bluff face retreat may be considered a direct function.of toe retreat due :;,:i~ cumulative effect of progressive oversteepenlng and erosional It is reasonable to expect that bluff face retreat will progress at a rate no greater than toe retreat. Control of erosional forces (i.e. wave attack) can further reduce the rate of recession.
Based on our geotechnical evaluation of the bluff, protective measures for erosion at the toe of the bluff utilizing a wave-attack preventative device is recommended. We understand bluff protection devices currently being considered include a riprap revetment or cast-in-place concrete cantilever wall. Geotechnical considerations for each alternative are
presented in Sections 7.2, 7.3, and 7.4 of this report.
Our analysis of the stability of the bluff indicates that the bluff is grossly stable from a deep-seated standpoint, and the shore protection device should not be adversely affected by bluff instability landward of the shore protection device.
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l Laboratory tests indicate the soils present on the site have a negligible potential for sulfate attack on concrete. The onsite soils are moderately corrosive based on the results of pH and minimum resistivity tests. (Appendix C).
l Based on our subsurface exploration, we anticipate that excavation of the terrace deposits and Santiago formational soils can be generally accomplished with conventional heavy-duty earthwork equipment.
l The existing onsite soils appear to be suitable material for reuse as backfill material for construction purposes, provided they are relatively free of organic material, debris, and rock fragments larger than 6 inches in maximum dimension. Surface observations indicate that the soils derived from the terrace deposits are relatively cohesionless. Erodability of those cohesionless soils may be a constraint to slope design if landscaping is not established prior to the rainy season.
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7.0 RECOMMENDATIONS
For planning purposes, we provide the following recommendations relative to bluff protection.
7.1 my
Based on the results of our investigation and our geelogic
inter retations, .r the existing bluff has been analyzed for gross stab1 ity utilizing "Jambu's Simplified Method of Slices" (STABL V computer program) and Jambu's slope stability charts. The results of our slope stability analysis are provided in Appendix Il.
The strength parameters assumed in our analysis are based on our laboratory test results (Appendix C), our experience with similar units, and our professional judgement. The parameters utilized are as follows:
Moist Saturated Unit $ight Unit $ight Cohesion Friction Earth Material (D ) ID 1 (ocfl (dwrees)
Santiago Formation 120 130 100 32
Pleistocene Terrace 120 130 50 23 Deposits
There currently exists a potential for sloughing and blockfalls al;;: the bluff face due to the bluff's oversteepened condition. potential for sloughing and blockfalls may be effectively eliminated by construction of a cantilever wall or rock revetment as discussed in the following sections.
7.2 Construction Considerations for Bluff/Shore Protection Device
Based on thet;eault;h;f our subsurface investigation and analysis, recommend proposed stabilization measures for t:i bluff/shoreline consist of either a rock revetment as described in
Reference 18, Appendix A, or a cantilever wall as discussed below. Rock revetment design is within the purview of the project Coastal Engineer.
In either case, existing cobbles and sand should be removed to competent formational soils to provide an adequate base for the rock revetment or wall foundation and mitigate the effects of potential liquefaction of the beach sands. Removal of the cobbles in the area of proposed im rovement 1 co bles will also help reduce scour caused by agitation of the against the bluff.
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subsurface exploration, a hand pit was dug.in the existjng subsurface exploration, a hand pit was dug.in the existjng ;;,::e bluff face to a depth of 4 feet without reaching ;;,::e bluff face to a depth of 4 feet without reaching . We anticipate that the,cobble layer is on the-order . We anticipate that the,cobble layer is on the-order
During our cobbles west formational of 6 to 8 feet thick. However, several backhoe trenches should be excavated prior to construction to evaluate the actual depth to formational soils.
7.2.1 Excavation and Construction Dewatering
Excavations may extend below the ground water level during high tides. Therefore, discussed below.
construction dewatering may be required as Excavations deeper than 5 feet should have side slopes not steeper than 1:l (horizontal to vertical) if construction workers are to enter such excavations.
Oewatering of the proposed excavation may be accomplished by conventional open pumping using contractor's submersible or diaphragm pumps. Water should be pumped from sumps excavated about 2 feet deeper than the excavations and conveyed to a point outside the excavation area. Due to the high permeability of the cobble laver. construction of a sand berm around the excavations may be desirable to during construction.
7.3 Rock Revetment Desiqn Considerations
help reduce inflow of water
A rock revetment is considered suitable for protection of the bluff from a geotechnical standpoint since it can tolerate minor consolidation without structural failure. In addition, a rock revetment allows for the relief of hydrostatic uplift pressures generated by wave action due to its high permability and free draining characteristics. The design of the rock revetment is within the purview of the project coastal engineer. However, the following geotechnical recommendations should be considered in the design and construction of the rock revetment.
7.3.1 Revetment Backcut
Our slope stability analysis indicates the terrace sands comprising the bluff should be temporarily stable at an inclination of 1.5:1 (horizontal to vertical) to allow for the construction of the revetment. Due to the granular nature of these terrace deposits, the backcut should not be exposed unprotected for long periods of time. We recommend the geotechnical consultant map the backcut for potentially adverse geologic conditions.
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7.3.2 Filter Fabric
As mentioned in Reference 18, A pendix A, a woven geofabric should be placed beneath the Ii edding layer of the revetment. The filter geofabric acts as an energy dissipator by shielding the slope from the erosive forces of moving water and filters to help prevent the washout of soil fines. The type of geofabric used should be based upon the grain size analysis of the soil comprising the revetment backcut.
7.4 )
As an alternative to a rock revetment, a gravity/cantilever type seawall may be considered, as shown on Figure 5. The actual design and
configuration of a seawall should be designed by a structural engineer in consultation with the geotechnical consultant and coastal engineer.
Due to the potential scour at the front of the wall, we recommend that passive resistance seaward of the foundation be neglected. Overturning moments should be resisted by soil bearing and fill weight on the heel of the foundation. For design purposes, a moist soil unit weight of 120 pounds per cubic foot and a saturated soil unit weight of 130 pounds per cubic foot may be assumed.
7.4.1 Foundation Desiqn
The proposed seawall may be supported by conventional footings founded at least 2 feet into undisturbed formational soils with a 4 foot minimum key on the seaward side of the footing. At this embedment, footings may be designed using an allowable soil bearing pressure of 3,000 psf. The allowable pressure may be increased by one-third for loads of short duration such as wind or seismic forces. Additional protection at the front of the footing such as rip rap may be desirable to further reduce erosion potential. engineer. Details should be provided by the coastal
7.4.2 Lateral. Resistance
Foundation may be designed using a coefficient of friction of 0.30 (total frictional resistance equals coefficient of friction times dead load on footing). This value may be increased by one-third for wind or seismic loads.
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The proposed seawall should be designed for lateral earth pressures for static and dynamic loading conditions. For calculations of lateral earth pressures, we have assumed that the wall will yield enough to mobilize the full shear strength of the soil. Lateral earth pressures for static and dynamic loads for saturated and unsaturated conditions will be provided upon your request if this alternative is chosen.
7.4.4 Drainaqe
The proposed seawall should be provided with appropriate drainage. A drain consisting of 3/4-inch washed gravel wrapped in Mirafi 140N filter fabric should be provided at the back of the wall. The gravel should extend behind the wall at least 2 feet horizontally and from the base of the wall to within 2 feet of the top of the wall. Weep holes should be provided at frequent, horizontal and vertical intervals so accumulation of beach sands or other materials will not impede drainage.
7.5 Backfill
The onsite terrace deposit soils are sufficiently granular and are generally suitable for use as backfill material.. These onsite soils should be screened of organic matter, debris and rock fragments greater than 6 inches in maximum dimension Backfill should be compacted in uniform lifts (not exceeding 8 inches in thickness) by mechanical means to at least 90 percent relative compaction (ASTM Test Method 01557-78).
7.6 Tvoe of Cement for Construction
Concrete in direct contact with soil or watE;bai;: contain:h&iiii concentration of soluble sulfates can be deterioration commonly known as "sulfate attack." Based 0i'U.S. Bureau of Reclamation criteria, the potential for sulfate attack is negli ible for sulfate contents ranging from 0 to 150 ppm. Soluble su fate 9 contents of samples tested at this site were within this range (Appendix C). Foundation members and the proposed seawall should not
require the use of sulfate-resistant cement.
7.7 Corrosivitv
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Minimum resistivity and pH tests were performed on representative samples of the onsite soils (Appendi;oi). Based on our results. the onsite soils are moderately corrosive. ( ;ideration should be aiven to protection of steel exposed to salt water.
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7.8 Construction
The recommendations provided in this report are based on preliminary design information for the proposed bluff protection improvements ;;II subsurface conditions disclosed by widely spaced borin s. interpolated subsurface conditions should be checked in the fie d during 8 construction by representatives of Leighton and Associates. Final project drawings should be reviewed by the geotechnical engineer prior to beginning construction.
Construction observation of site excavations and field density tests of all compacted fill should be performed by the geotechnical consultant to
document that construction is performed in accordance with the recommendations of this report.
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TABLE 1
SEISMIC PARAMETERS FOR ACTIVE FAULTS
Beach/Carlsbad
I I I
Potential Causative Fault
Distance From Fault
To Site
(Miles)
Maxlmum MAXIMUM PROBABLE EARTHQUAKE
Credible I (Functional Basis Earthquake)
Earthquake Peak Bedrock/ Predominant Ouration of
Repeatable i';';o;nAt Strong
Richter Richter Horizontal Ground Acceleration**
Shaking at
Magnitude Magnitude Seconds Site In
(Gravity) Seconds
22 NE 7.5 7.3 0.24 0.35 25
19 NW 7.0 6.5 0.16 0.30 13
Elsinore
lewport-Ingle- Mood (offshore)
Coronado Banks 20 SW 6.5 6.0 0.10
[offshore) 0.26 6
San Jacinto 47 NE 7.5 7.3 0.10 0.42 11
San Andreas 62 NE 8.5 8.3 0.11 0.62 7
San Clemente 53 SW 7.5 7.0 0.05 (offshore)
0.42 7
iose Canyon*
(offshore)
.a Nation*
4 SW 6.8 NA --me -m-e --
31 SE 6.5 NA ____ --me --
* This fault is considered "potentially active" based on our current knowledge of the geologic conditions of
thr San Dirge County area,
** For 'design purposes. the repeatable horfzontal ground acceleratfon may be taken as 65 percent of the peak acceleration for the site wfthfn it20 mfles of the eptcenter (after Ploessel and Slosson, 1974).
Base Map: U.S.&S. San Luis Rey, Califoids Quadrangle
0 2000 4000
7 feet
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CARL,SBAD, CAUFORNIA
APPENDIX A
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APPENDIX A
REFERENCES
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Abbott, P.L., ed., 1985, On the Manner of Deposition of the Eocene Strata in Northern San Diego County, San Diego Association of Geologists Fieldtrip Guidebook.
Albee, A.L., and Smith, J.L, 1966, Earthquake Characteristics and Fault Activity in Southern California &I Lung, R. and Proctor, R., eds., Engineering Geologist in Southern California, Association of Engineering Geologists, Special Publication, dated October.
Allen, C.R., Amand, P., Richter C.F., and Nordquist, J.M., 1965, Relationship Between Seismicity and Geologic Structure in Southern California, Seismological Society of America Bulletin, Vol. 55, No. 4, pp. 753-797.
Artim, E.R., 1985, Erosion and Retreat of Sea Cliffs, San Diego County, California, &I McGrath, J. (ed.), California's Battered Coast, Proceedings From a Conference on Coastal Erosion, San Diego, California, dated September 1985.
BANDB Engin~ee;s,M;;;., 1984, Precise Grading Plan for CT-81-35/CP-182, Pointe in the City of Carlsbad, State of Scale l"=iO', California, Sheet 2 of 3 sheets, dated March 26, approved July 2.
Bell, J.M., 1966, Dimensionless Parameters for Homogeneous Earth Slopes, Journal, Soil Mechanics and Foundations Division, American Society of Civil Engineers, No. SM5, September.
Benton Engineering, Inc., 1979, "Addendum to our Report Entitled Proposed Two-Story Residential Buildings, North of Ocean Street and South of Buena Vista Lagoon, Carlsbad, California, Dated May 8, 1979," dated August 31.
Bolt, B.A., 1973, Duration of Strong Ground Motion, Proc. Fifth World Conference on Earthquake Engineering, Rome, Paper No. 292, pp. 1304-1313, dated June.
Bonilla, M.J., 1970, Surface Faulting and Related Effects .& Wiegel, R. (editor), Earthquake Engineering, Prentice-Hall, Inc., New Jersey, pp. 47-74.
California Division of Mines and Geology, 1975, Fault Map of California, Scale 1"=750,000'.
County of San Diego, 1975, Orthtopographic Survey Map, Sheet No. 362-1659,
Scale 1”=200’.
A-I
-
- 8880700-01
REFERENCES (Continued)
-~
-
-
-
-
-
--
-
-~
-
Greensfelder, R.W., 1974, Maximum Credible Rock Acceleration from Earthquakes in California, California Division of Mines and Geology, Map Sheet 23.
Hannan, D.L., 1975, Faulting in the Oceanside, Carlsbad, and Vista Areas, p,rthe;rns San D;ego County, California j.~ Ross, A. and Dowlen,
* ., Studies on the Geology of Camp Pendleton and Western San Diego' County, California, San Diego Association of Geologist Field Trip Guidebook, pp. 56-60.
Hart, 1985, Fault-Rupture Hazard Zones in California, Alguist-Priolo 'Qecial Studies Zones Act of 1972 with Index to Special Study Zones Maps: Department of Conservation, Division of Mines and Geology, Special Publication 42.
Hileman, J.A., Allen, C.R., and Nordquist, J.M., 1973, Seismicity of the Southern California Region, 1 January 1932 to 31 December 1972: California Institute of Technology Seismological Laboratory, Pasadena, California.
Jennings, C.W., 1975, Fault Map of California, Scale 1:750,000: California Division of Mines and Geology, Geologic Map No. 1.
Kuhn, G.G., and Shepard, F.P., 1984, Sea Cliffs, Beaches and Coastal Valleys of San Diego County, Some Amazing Histories and Some Horrifying Implications, Berkeley and Los Angeles, University of California Press, pp. 3-38 and 69-95.
Lamar, D.L., Merifield, P.M., and Proctor, R.J., 1973, Earthquake Recurrence
Intervals on Major Faults in Southern California Jo Moran, D.E., Slosson, J.E., Stone, R.O., Yelverton, California, eds., 1973, Geology, Seismicity, and Environmental Impact: Association of Engineering Geologists, Special Publication.
Leighton and Associates, Inc., Unpublished In-House Data.
, 1984, Preliminary Geotechnical Investigation Proposed South Ridge Trails Parcel C, 1 through 8, and Parcel D, 2 through 4, Oceanside, California, Project No. 4841134-01.
Moffatt and Nichol Engineers, 1988, Shore Protection Concept Study, File No. 2499, Carlsbad, California, dated March 15.
Ploessel, M.R., and Slosson, J.E., 1974, Repeatable High Ground Accelerations from Earthquakes-Important Design Criteria, California Geology, Vol. 27, No. 9, dated September.
A-2
-
- 8880700-01
REFERENCES (Continued)
-
-
-
Power, M.S., Dawson, A.W., et. al., 1982, Evaluation of Liquefaction
Susceptibility in the San Diego, California Urban Area, Final Technical Report, Volumes I and II, Sponsored by the U.S.
Geological Survey.
Schnabel, B. and Seed, H.G., 1974, Accelerations in Rock for Earthquakes in the Western United States, Bulletin of the Seismological Society of America, Vol. 63, No. 2, pp. 501-516.
Seed, H.B., 1979, Soil Liquefaction and Cyclic Mobility Evaluation for Level Ground During Earthquakes, ASCE, GT2, p. 201, dated February.
Seed, H.B., Idriss, I.M., and Arango, Ignacio, 1983, Evaluation of Liquefaction Potential using Field Performance Data, ASCE JGE, Vol. 109, No. 3, p. 458, dated March.
Seed, H.B., Idriss, I.M., and Kiefer, F.W., 1969, Characteristics of Rock
Motions ' Earthquakes Journal of Soil Mechanics and Foundation?Lf!gsion ASCE, Voi. 95, No. SM5, pp. 1199-1218, Septehber. Proc. Paper 6783,
United States Department of the Interior Geologic Survey, 1968, 7.5~Minute San Luis Rey Quadrangle, Scale 1"=24,000', Photo Revised 1975.
Weber, F. Harold Jr., 1982, Recent Slope Failures, Ancient Landslides and Related Geology of the North-Central Coastal Area, San Diego County, California, California Division of Mines and Geology, Open File Report 82-12, LA.
-
AERIAL PHOTOGRAPHS
Source Flight Photo No. Scale Date
San Diego County 22A 3 and 4 1"=100' 1928
USDA AXN-14M 19 and 20 1"=1,667' 1953
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A-3
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APPENDIX B
GJfoT8oufIcu BORING LOG - Date Mav 27. 1988 Drill Hole No. R-I SheetLot&
Project EeachKarlsbad Job No.. 8880700-01
- Drilling CO. Aztec Drilling ‘lype of RiR Hollow-Stem Auger
Nolo Dismeter 6" Drivs Weight 140 pounds Drop 30 in.
.-
-
.-
-
--
-
-
_-
--
-
ilsvstion
” i, 20 31 !I! u* I 0 .
,p of
3 .::
=: <
ner -
i; 2::; 4; - -
!.3
'.3
G 3
Dr
. :* i” >c
:” Q -
SW
P= SI
g
turn Mean Sea Level
,,.,,I
arppld by J8
PLEISTOCENE TERRACE DEPOSITS:
- . .
5- -
_ . . '0.
_ -0. 0
0 :.
- . .
. .
. . -. .
. . . .
5-
o-
5-
1
Gray to light brown-gray, dry, medium dense
relatively clean, quartz-rich, fine- to
coa~rse-grained sand; trace of silt; locally slightly cemented; generally friable,
some scattered root hairs; some scattered
subrounded to well rounded pebbles and cobbles
8 8' Becomes cobblely; difficulty in
drilling
@ 10' Pale gray, damp, loose, silty, fine-
to coarse-grained sand; micaceous;
some scattered, rounded quartz and
lithic pebbles; friable
@ 15' Siltstone; Pale, olive-gray. moist, hard, clayey silt to clayey, fine-
grained sand; appears massive; unifo
Total Depth = 16 Feet
No Ground Water Encountered
No Caving Backfilled 5/27/88
.-..
.-. -.. ^
.-
-
-
.~.
.
..~
-.
-
-
-
-
_
-_
GEun!op(IcAL BORING LOG
Data Mav 27. 1988 Drill Hole No. 8-7 shert>f&
hject Beach/Carlsbad Job No.. 8880700-01
Drilling co. Type of Ri~ollow-Stem Auger Aztec Drillinq
Hole Diameter 6” Drive Weight 140 pounds D-P 30 ia.
Elevation ‘for, of Hole flf
2 fu Cal Lg 2’
Ia “I
0-- . . . I . . . 1 . . - .a . . .
5- . ‘6’
o-
5-
o-
5-
ROl -
iid
$1 ..I,
2;
- -
3.s z
or - . t’ .” zr
2” 8: -
F-
SM
E!
mm Mean Sea Level
GE0TEQpsIcu DESCRIPTIQ
+=wvd by JB
kunplod by JB
PLEISTOCENE TERRACE DEPOSITS:
@ 5' Light orange-gray to lightorange-
brown, dry to damp, loose, silty,
I
fine- to medium-grained saad;'some
scattered subrounded pebbles and cobbles; friable; some root hairs;
I
slightly.micaceous
@ 6' Refusal on cobble larer
Total Depth = 6 Feet
No Ground Water Encountered
Refusal @ 6 Feet Backfilled 5/27/88
GEt?lTmNIcAL BDRINC LOG
- Dota Mav 77. 1988 Drill Hole No. 8-3 shoot~ofl&
Project 8eachKarlsbad Job No.. 8880700-01
Drilling co. Typo of Ript Hollow-Stem Auger Aztec Drillinq
Ho10 Diaaotar 6” Drive Weight 140 pounds Drop 30 in.
-.
-
-
-
-
-
-
-
-
-,
of Ho10 t15' - 0
ii;
k - -
_-
13.
-
5.9 c
nor -
g;
:::1 4; - -
1.5
5.:
g
-
Or
. *c
:”
cir
2’
g
-
SP.
SM
-
iM
ir 21!
-
Ds ttum Mean Sea Level
,,.,
8 5' Light to medium red-brown, dry, mediu
dense, silty, fine- to medimgrained
sand; friable; few scattered, rounded pebbles; locally slightly cemented
8 10’ Pale to medium gray, damp to moist,
medium dense, silty, fine-grained
sand; massive; slightly cemented
SANTIAGO FORMATION:
9 E~~Siltstone; Pale olive-gray. moist,
No Caving
Backfilled 5/27/88
. I f
GEuTEm1cu BORIMG LOG
~ Doto Mav 27. 1988 Drill Ho10 No. B-4 saoot~of~
Project Beach/Carlsbad Job No.. 8880700-01
Drilling co. 'Qpo of Big Hollow-Stem Auqer Aztec Drillinq
Ho10 Diameter 6" Drive Yoight 140 pounds Drop 30 in.
-
.,-.
_-
~~-
-
-
,-
-
-
-
-~
-
2p of
4 .:: =: <
1.
17.
-
18 q
Rot. or - .
1’ *u
3i
=c/
E -
SW
-
SP
z
,tum Mean Sea Level
GEoTEQuiIcAL ccscRxPTIa
tagged by JB
amplod by JB
PLEISTOCENE TERRACE DEPOSITS:
Light gray, dry, medium dense, relatively
clean, quartz-rich, fine- to coarse-grainec
sand; friable; abundant scatted, sub-
rounded to rounded pebbles
8 IO' Pale gray to off-white, m. dense,
clean, quartz-rich, fine- to medium-
grained sand; massive; fsiable;
slightly micaceous with laal sub-
rounded pebbles and cobbles
SANTIAGO FORMl SANTIAGO FORMATION: @ 15 Siltstol @ 15 Siltstone; olive-gray, moist, hard,
clayey sil, clayey silt to clayey, fir-grained
sand; mass' sand; massive; some local orange-
brown iron oxide brown iron oxide staining; locally
cemented I
Total Depth = 16 Feet No Ground Water Encountered No Caving Backfilled 5/27/88
APPENDIX C
8880700-01
-
-
-
-
-
-
-
-
-
-
APPENDIX C
SAMPLING AND LABORATORY TESTING PROCEDURES AND LABORATORY TEST RESULTS
SAMPLING PROCEDURES
Undisturbed Samoles: Samples of the subsurface materials were obtained from the exploratory boring in relatively undisturbed conditions. The depth at which each undisturbed sample was obtained is shown on the boring log.
The sampler used to obtain undisturbed sam les is a split-core barrel drive R sampler with an external diameter of 3.0 inc es which is lined with thin brass rings with an inside diameter of 2.41 inches. Each ring is 1 inch long.
The sample barrel is driven into the ground with an effective weight of the kelly bar of the boring machine. The kelly bar is permitted to free fall. The approximate length of the fall, the approximate weight of the bar, and the number of blows per foot of driving are noted and recorded on the boring logs. Blow counts have been noted in the log of borings as an index to the
relative resistance of the sampled material.
The samples are removed from the sample barrel in the brass rings, sealed, and transported to the laboratory for testing.
Disturbed Samoles: Bulk samples of representative materials were also obtained from the borings, bagged, and transported to our laboratory for testing.
LABORATORY TESTING PROCEDURES
Moisture Densitv Tests: Moisture content and dry density determinations were performed on relatively undisturbed samples obtained from the test boring. The results of these tests are presented on the boring log.
Direct Shear Tests: Direct shear tests were performed on relatively undisturbed samples in accordance with ASTM Test Method D3080 at a strain
rate of 0.05 inches per minute to determine cohesion and the angle of internal friction of the soil sample.
C-l
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- 8880700-01
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-
-
--
-
-
-
SAMPLING AND LABORATORY TESTING PROCEDURES AND LABORATORY TEST RESULTS (Continued)
Classification Tests: Typical materials were subjected to mechanical grain- size analysis by wet sieving with U.S. Standard brass screens (ASTM Test Method 0422). The data was evaluated in determining the classification of materials. A graphical presentation of the grain-size distribution is presented in the test data, and the Unified Soil Classification is presented in the test data and the boring logs.
Soluble Sulfate Tests: The percent of soluble sulfates in a representative sample was determined by the California Materials Method No. 417 utilizing a hand-held terbidmeter.
pH and Minimum Resistivitv Tests: Determination of pH and minimum resistivity value for typical subsurface soils was made for analysis of corrosion potential.
GENERAL NOTE:
All references to the American Society for Testing and Materials (ASTM) imply the latest standards.
c-2 -
1. ‘pH, MINIMUM RESISTNITY AND SOLUBLE SULFATE TEST RESULTS
SAMPLE LOCATION PH MNMUM RESISTIWTY S0LUSt.E SULFATI
(ohm-cm) f4m-d
1 B-l, 1 @ 0 to 5' 7.2 5,670 90
B-l, 3 @ 15 to 16' 8.2 5,300 _-
1 B-3, 3 @ 5'
1
1
1
..I
1
1 .’
1
1
J
I
-I
J
,.I
1
--- ---mm 60
8880700-01
I BEACWCARLSBAD
--
-
-
-
-
-.
0
NORMAL STRESS IKF)
OESCWPTION SYMBOL BORING UYPLE
NUMBER NUMBER DEPTH (FEET) COHEEION FRICTION SOIL
(RIP) ANoiE TYPE
Jndisturbed . B-l 1 5 to 6 190 37O SW
Undisturbed 0 B-3 3 15 to 16 660 26” ML
BEACtl/CARLSBAD
I DIRECT SHEAR TEST
RESULTS I
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- 8880700-01
APPENDIX D
STABILITY ANALYSIS
(STABL V Program)
-
-
-
-
STABL is a computer program written in FORTRAN IV source language for the general solution of slope stability problems by a two-dimensional limiting equilibrium method. The calculation of the factor of safety against instability of a slope is performed by a method of slices. The particular
methods employed in this version (STABL V) are the modified Bishop method, applicable to circular-shaped failure surfaces, and the simplified Janbu method, applicable to failure surfaces of general shape.
STABL features unique random techniques for generation of potential failure surfaces for subsequent determination of the more critical surfaces and their ;;;;;;pnding factors of safety. One technique generates circular surfaces;
surfaces of sliding block character; and a third, more general irregulir surfaces of random shape. The means for defining a specific trial failure surface and analyzing it is also provided.
Conditions which STABL is programmed to handle include the following: heterogeneous soil systems, anisotropic soil strength properties, excess pore water pressure due to shear, static ground water and surface water, pseudo- static earthquake loading, and surcharge boundary loading.
In our landslide stability analysis, a sliding block routine was implemented in which a well-defined weak zone (i.e., area of basal rupture) is specified. "Boxes" are designated at various points along the weak layer and points are randomly selected within each box. Subsequently, two points within adjacent boxes are connected with a straight line segment which is then used as the
central block of the sliding mass. In cases where the basal rupture is confined to a very thin well-defined failure surface, individual points mere specified instead of boxes for generation of line segments at the base of the central block.
After the base of the central block is created, the active and passive portions (heal and toe) of the trial failure surface are generated using line segments of equal specified length. The ten most critical failure surfaces ;r-;-ihen listed in the order of the most critical (lowest factor of safety)
resisting The factor of safety was calculated as the ratio between the forces and the driving forces required for the equilibrium. -
-
D-l
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8880700-01
STABILITY ANALYSIS (Continued1
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Computer printouts of calculations for back-calculated streng!th parameters, existing landslide stability, appendix. and buttress design are provided in this A low quality plot of the problem geometry is provided in this appendix. A low quality lot of the problem geometry is provided at the end of each printout. It shou d be noted that for plotting purposes, the Y Y coordinates specified in the calculations may not be the same as the elevations indicated on the geologic cross-sections. An explanation of the
print characters for the plot is provided below.
end points of ground surface and subsurface profile boundaries end points defining surface generation boundaries points defining the water surface points defining the most critical generated surface points defining the second most critical generated surface points defining the third most critical generated surface points defining the fourth most critical generated surface points defining the fifth most critical generated surface points defining the sixth most critical enerated surface points defining the seventh most critica 9 generated surface points defining the eighth most critical generated surface points defining the ninth most critical generated surface points defining the tenth most critical surface points defining the remaining generated surfaces points defining a specified trial failure surface points defining the location of surcharge boundary loads
-
-
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- D-2
-
-
--Blope S.tabi.li.ty Rnalys:i.s-- s i 1 p I 1. ,F :i e !j .I’ z, n b I, , !Sinbpli~fied Eci5hop 0 ‘3. s p e 1’1 c e .I. * E l’kthod of Slices .-
-
-
-
-
-
-
-
-
RUIJNDARY CCIDRDINNES
G Top Bounda?ie~
9 Tota: Hnundn~ries
Boundary
No.
X-Left Y-Left
( F t 1 ( f t 1
-00 10.00 22.00 14.00
22.00 14.00 23.00 17.00
23,OO 17.00 26.00 18.00
26.00 la. 00 50.00 26.00
50.00 26.00 59.00 30.00
59.00 30.00 100.00 30.00
-00 8.00 20.00 9.00
20.00 9.00 22.00 14.00
20.00 9.00 ioo.00 9.00
X-Right
(-f.t)
Y-Right (f-t)
-
-
-
-,
-
Soil Type l&low Fmd
,~~.
.-
.-
_-
-
-
-
~su~r~iw:cc SOIL wwmrms
3 'Type(s) of Soil
Soil Total Saturated Cohesion Friction PCYI-e PW?SSUTe Piez.
Type IJnit Wt. Unit W-k. :tntevcegI: Rngle I'~re):sz.ure constant Suvface
NO. (pcf) (pcf) (p5.F) (cleg) Param. (ps.f) No.
1 120.0 ,130.o .O 25.0 -00 .O 1
2 120.0 130.0 100.0 32.0 -00 .O 1
3 1aj.o 130.0 500.0 23.0 -00 .O 1
-
-
-
-
-
:L F':[E%Ul'lEIHIC! SUKFRCE(S) HRUE BEEN SF'ECIFIEiD
U1-l~it weigtrt 0.f Wa~teT := 62.40
Ciczomet~ric Su.rf~~:e No. 1 Specified by 4 Coordinate Points
F’ (3 i n t X-Wa~te’r Y-Watw-
Wl3" cft) (ft)
1 -00 10.00 2 22.00 10.00 3 30.00 15.00 4 100.00 15.00
,-
-
Sewching Hautine Will He Lim:i.t;sd To Fin FIwa Defined By 1 Bounda.ries
0.f Which ‘The Firc,,t I IIoundar~es Will Def1ec.t Surfacec, Upward
I3cK:~da~ry X.-Le.f.t; Y-Le.ft X-Right Y-Right
Ho. ( ,F t ) ( f .t ) ( ,f t ) (ft)
1 .oo .oo 100.00 . 00
-
.-
-
-
-
.-
63 C,ri.t.ioal Failure I&r.face !Zearrhing Ilethod, Using 19 Random 'Technique For Gene~ra~l:ing Ci~rcccla~r Sctv~faces, Has Heen Specified.
-
125 ‘TPiAl Su.r.face5 Have Been GeIleva.t@d.
25 Swrfaces Initiate F~oa Each 0.f 5 Points Equally Spaced
Rlong ‘The Grwrnd Gurface IUetween x :I 10.00 ft.
and x = 20.00 .f.t;.
Each 5u.r. facr Te.rmic&es !3etwc>a,> x :i 24.00 fit.
a n d x rs 70.00 ft.
Unless Fu.rther Limi.takions Were :Imposed, The Ilininium Eleva'cion
At Which Q .%c?faoe Extends Is y i- .oo ft.
3.00 ft. Line Gegments Drfino Each Trial Failure Gurface.
Restrictions Have Been Imposed Upon The fingle Of Initiation.
The ibgle Has Heen Res.t.ricted Between The fb~gles Of -35.0
and .O deg.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
I"'o:L:Lowinq Wr.e Displayed The ‘Ten Mos-t C-rktical 0.f The T.rial
Fn:ilr*re Swfaco5 Exan1ined. 'They Wre Ordered - Ilo~;~t Cvitical FiPSt.
* * Scfety Fartow 0.r~) Cslcula.ted Ny ‘The modified Janbu Method * +
Fai Iu~e Surface Spec.i fiwl Ny 7 Cooi-dinate Points
Point X-SLl'r-.f Y-SLLi-F IJO. i,ft) c -I; .t )
I 15.00 J.2. ‘73
I I._ 1-7.92 1%. 02
3 20.91 12 2 . 2
4 23.71 13.31
5 25.0s 1'5.17
6 2 7 . 7 4 17.66
7 28.04 18.68
*x* i.36a Y * +
Failure Surface Specified By 12 Coordinate Points
Point No. X-SuT.P
(ft)
Y-sLll.f
(ft)
1 10.00 11.82
2 12.78 10.69
3 15.70 9.99
4 18.69 9.73
5 21.68 9.91
6 24.62 10.54
7 27.43 11.53
8 30.05 13.05
3 32.43 14.87
10 34.51 17.03
11 36. ps 13.46
12 37.44 21.81
* * * 1.972 * Y .*
-
-
-
-
-
-
-
Failu're S~wface Spec:r~fied Hy 14 Cowrdinate Poirvts
IP 0 .i 1'1 ,t
al.
1 12.50 I 2 . 27
2 15.10 10.13
3 18.0<3 ':3 'yg
4 20.39 '3.48
5 2i3.37 3 . 3 3
6 26.77 3.73
7 23. a.7 10.30
a 32.63 11.68
3 3:s. 1'3 13. 25
10 37. *,g It:;. 16
I 1 3 9 _ 5 0 1'7. ;31'
12 41.17 13.89
:t 3 4 <2 . 4 i6 22.60
14 42.76 23.59
.*(?o(
X-Surf
(fti)
1.783
Y ~--!;uvf (ft)
.x w *
Failu're Su'rface Specified By 8 Coordinate Points
Point
No.
X-Surf Y-SU'Pf
(ftG> (.flT)
12.50 12.27
is.41 11.53
18.41 11.51
21.32 12.21
23.93 13.60
26.24 15.58
27.'35 18.04
28.21 18.74
I(** 1.98'3 **.s
-
-
-
-
-
-
-
-
-
-
-
-
-
i=ai:turr Scc.r.face Speci.fied E{y 12 Coordinate F'o:iwks
I-‘,, i n t No.
L 2 3 4 5 6 '7 a g
10
1 1. .L 2
x '.- s l., 7' .f
(ftz)
12.50 12.27 15.28 11.13 18.20 IO. 45 21.13 10.23 24.18 10. 4'3 27.09 11.23 23. a4 I2 . 4 :I. 32.38 14.01 34.63 '1 Fj _ t.j 9 3‘. 5,; 18.3:i 38. 06 a.! 0 I 8 3 38.56 22.19
.*** 1.3’36 .* :* i(
Failuve Surface Specified By 8 Coordinate Points
point X-Sur,f (.flT) Y-SLlV~f (ft)
12.50 12.27 15.35 il.33 18.34 11.10 21.30 11.62 24.04 12.83 26.40 14.68 28.24 17.05 29.12 19.04
*** 1.997 ***
-
-
,.-
-
-.
-.
Failu-t-e Srtr~face speci .fied By L Coordinate Points
POid X.-SuYf
No. ( ,f-t)
1 17.50
2 20.47
s 23.3'7 4 2sm 7s
5 2’7. 2 I.
L 27.26
13.18 12.72
13.47
15.30 17.32
18.42
*** I. . wa X.3(:*
F7a:iIu~re Su'rface Speoi.fied Hy S Coordinate Points
Point
No.
***
x.-5ur.f
(ft)
17. so
20.45 23.33 25.51
26.44
2.000
Y-Suvf
(ft)
13.18
12.63
13.48 15.54 18.15
***
-
-
_-
-
-
-
-
-.
-
-
-
-
-
-
-.
-
-
-
-
Failuve Surface Spec.i..fied By 7 l:oovdinatr IPo:iwta
Point;
No.
1
2
3 4
s
c
'7
x-.ck.tT- f
(ft)
Y-Surf
( f,t)
1s. 00 12.73
1'7.R6 11.81
20. OG 11.35
2 3 . c 2 13.11 2s. 82 15.15
27.1'7 17.83 27. 24 18.41
x * Y 2.005 ic >x x
Failu're Sur.face Specified By 6 Cawrdinate Points
PO i nt X-Surf
l-lo. (ft)
Y-Surf
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