APPENDIX F Geotechnical Investigation Report

                                         

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d < i b q o lf 2 & I : S e r v i c e sC o r p o r q t i a n

GEOLABS -\ME STLAKE VI L LAGEFourrclct t ion crnd Soi ls Engrineerirrgr, Geology

31119 Via Colinas, Suite 5O2 o Westlake Vil lage, CA 91362

V o i c e : ( 8 1 8 ) a A 9 - 2 5 6 2 ( 8 O 5 ) 4 9 5 - 2 1 9 7

r u : ( a 1 a ) 8 a 9 - 2 9 9 5 ( 8 o 5 ) 3 7 9 - 2 6 0 3

January 27,2009w.o.872s

President Asset Group260 Newport Center Drive, 3'o FloorNewport Beach, Califomia 92660

Attention: Mr. Nick Ni

Subject: Supplemental Geotechnical ReportRevised Tentative Tract No. 53426,9503 Andora Avenue,City of Los Angeles, Califomia

Mr. Ni,

ln accordance with your request, we have prepared this report to address revisions to the

Tentative Tract Map (provided to our office on by the project civil engineer Robert Kameoka).

These revisions prompted supplemental geologic mapping, laboratory testing of samples already

obtained from previous investigation, and slope stability analyses. The results of the

aforementioned items are included in this report.

Tentative Tract Map Revisions

The most recent plan we have is an undated Tentative Tract Map by Robert Kameoka

with a note indicating a September, 2008 revision. This map, revised from the plan used in our

May 20, 2003 report (see References), calls for construction of 45 residential lots and 3 open

space lots. While there appears to be arearrangement of some of the lot lines, and an additional

pad (Lot 37) and associated 35 feet tall2:l gradient cut slope in the extreme northwest portion of

the tentativetract, the significant changes to be addressed in this report are the introduction of

two l : l gradientcuts lopeswi tht rvo l0- footh ighreta in ingwal lsat thetoeof eachof thesecut

President Asset Group January 27,2009w.o .8725

slopes. For the purposes of discussion, the height of the retaining walls is included in the total

height of the slope. The map proposes an approximately 115 feet tall 1:l gradient cut slope

ascending above the proposed private street in the vicinity of lots 25-27, and an approximately

71 feet tall 1:1 gadient cut slope ascending above the proposed private street in the vicinity of

lots 30-36. Evaluation of the global stability of these fwo slopes is discussed in this report.

Slope Stabilitv

We have evaluated the global stability of the tallest proposed I : I cut slope using strength

values determined through principles of rock mechanics, including six unconfined compression

tests on samples recovered during an earlier investigation (Bl and B2). Bedding and structural

discontinuities were mapped by our geologist in the areas of the proposed cut slopes. The earth

materials in the vicinity of the proposed cut slopes consist of thickly-bedded to massive,

cemented, medium and coarse grained sandstone assigned to the Cretaceous-age Chatsworth

Formation. The areas in question are charactenzed by resistant sandstone cliffs and slopes

locally as steep as l:1 (horizontal to vertical) gradient (which made drilling access to this area

impossible). The bedding strikes approximately northeast and dips approximately l5-25 degrees

to the northwest. Based on our recent geologic mapping this area appears devoid of fine-grained

beds, and infrequent, steep joints were mapped. Bedding will be supported in the proposed l:l

cut slopes.

The shear strength of the rock mass was modeled using a Hoek-Brown failure envelope

developed considering the average unconfined compression test values of intact rock samples,

structural geologic data, and rock quality (RQD) determined from the two borings (Bl and 82)

collected from an approximately 80 feet thick section of bedrock stratigraphically below the

section of bedrock in the area of the proposed cut slopes. Photographs of the cores taken

GEOLABS - \ME STLAKE \ , / I L LAGE

President Asset Group January 27,2009w.o.8725

included in Plates UCT.PI-

were prepared to illustrate the

immediately following the unconfined compression testing are

UCT.P3. Three new cross-sections (Section 2-2',3-3' and 4-4')

cut slopes,

The strength values derived from the Hoek-Brown failure criterion were applied to 2-O

limit equilibrium slope stability analyses. These values correlate to an angle of intemal frrction:

56 degrees, and a cohesion of 27,000 pounds per square feet. Stability analyses of proposed

slopes were performed using the computer software entitled SLIDE (version 5.038) by

Rocscience (2008). This software performs limit-equilibrium slope stability analyses.

Program ouput includes a description of the problem, including material boundaries, material

properties, earttrquake loading, searching criteria, and analysis method. Graphical depictions

of the ten most critical failure surfaces (or all surfaces below a critical safety factor where

applicable) and all failure surfaces considered are presented on the first two sheets of each

analysis. Static and pseudostatic calculations produce high factors of safety. These calculations

are included herein in Appendix A. The proposed cut slopes are thus anticipated to expose hard

cemented strata without sheared zones or weak beds, and are expected to perform well without

additional stabilization measures. They should be carefully mapped during grading to verify

strength and continuity of bedding. If weak beds are encountered, supplemental

recommendations mav be warranted.

Closure

This geotechnical report has been prepared in accordance with generally accepted

engineering practices at this time and location. No other warranties as to the professional advice

provided under the terms of our agreement and included in this report are expressed or implied.

EEOLABS -\NE ST LAKE \,ZI L LAGE

President Asset Group

Thank you for this opportunity to be of service.

any questions regarding this report.

Respectfu lly submitted,GEOLABS-WESTLAKE VILLAGE

January 27,2009w.o.8725

Please do not hesitate to call if vou have

z2Y=/-'<_.sk#';. s1-on<--E-'c.8.G.246r : , , i i <

O.ffii::::% Exo.09130/09

eharles A. Svl'lRbeoLoqsrEG e48 a**

"-Enclosures: Geologic Map Plate I

Bor ing Logs. . . . . . . . . . . . . . .P lates Bl and 82Cross-Section 1 - 1', 2-2', 3 -3', 4-4' . . . . . . . . . . . . . . . Plate 2.I -2.4Unconfined Compression Test Results .........Plate UCTPhotographs of Core Samples broken

during Unconfined Compression Tests .... Plates UCT.P I -UCT.P3Hoek-Brown Parameters .............. Plate HBSlope Stabil i ty Calculations ... . . . . . . . . . . . . . . . . . . . . . . . Appendix AReferences . . . . . . . . . . . . . . . . .P1ate R

XC: (a) City of Los Angeles Building and Safety(l) Addressee(l) Roben K. Kameoka

1047

wk6g

"jfitt"n%7 d/ oo,lelni sit*ltfic \-i ! i l 6 t 0 4 7 l ^w

GEOLABS - \NTE STLAKE VI L LAGE

SUBSURFACE DATA

GLIENT: Tone Yee PROJECT: Andora Road W.O.: 8725LOCATIONLo 47 ELEVATION: 1183' DATE: Bl12l03RIG TYPE: Cont. Core HAMMER WEIGHTS: DROP:

N U B M Recov DESCRIPTION ATTITUDES0 Chatsworth Formation: Fractured and weathered light brown to light

reddish brown medium grained SANDSTONE, massive to thicklybedded.

@6'- Light yellowish brown to light yellowish gray medium to coarsegrained SANDSTONE, massive, cemented fracture at 70", dense andmoderately hard, some sample removed to fit in box.

@11' - Light brown medium to pebbly very coarse grained SANDSTONE,thickly bedded with gradational contacts, cemented and hard, low-anglefracture at 14',55' fracture al14.5', small loss of circulation.

@16' - Pale brown pebbly coarse grained SANDSTONE, pebbles arevery small, unit is massive with gradational contact at base.@17.5'- Several graded beds, gray silty fine grained SANDSTONEgrading downward to pale brown medium to pebbly coarse grainedSANDSTONE, beds inclined 15-20", section contains re-cementedfractures dipping 60-80'.@22' - Gradationally interbedded medium to pebbly coarse grainedSANDSTONE with 1 gray silty fine grained SANDSTONE bed dippingt25' .

@20.5'- 1/4" thick, generally cemented and hard, steep re-cementedfracture 21-25'with new (spiral) fractures at 25'.

@26' - Light yellowish brown medium grained SANDSTONE, pebblyin top and bottom 6" with very small pebbles, iron stained fracture29-30.5', otherwise massive, hard.

@31.5' - Interbedded light brown to light yellowish brown mediumgrained SANDSTONE with dark gray siltstone (beds to 4" thick) andMUDSTONE, contacts dip 15-20", fine grained beds severely fracturedand poorly recovered, otheruvise cemented and hard.

@35'- Light brown medium grained SANDSTONE with sparse erodedbeds of gray to grayish brown SILTSTONE and silty fine grainedSANDSTONE, dipping 10' .@37' - Lost about 8", apparently medium grained SANDSTONE andgray SILTSTONE, 65" fracture from 36.5'-37'.@37.5'- Light brown medium grained SANDSTONE with sparseoxidation along bedding (about 10') and very sparse horizons of verysmall rip-ups, with gray mudstone beds 2-7" thick, that have internalsand ripples and traction features, otherwise cemented and hard

5

37o/o

'10

100%

15

100%

20

100%

25

100%

30

86%

35

83%

40

45ADDITIONAL COMMENTS:

Logged Geolabs-Westlake Village PLATE 81.,1

SURFACE DATA LOG OF BORING 81

CLIENT: Tone Yee PROJECT: Andora Road W,O.:8725LOCATION:Lot 47 ELEVATION: 1183' DATE: Bl12103R G TYPE: Cort. Core HAMMER WEIGHTS: DROP:

N U B M Recov DESCRIPTION ATTITUDES4C

@42' - Continues to 46', spiral fractures in bottom foot of interval, about70' fracture with oxide coating 42.5-43.5'was closed, bedding sparse,1 0 -1 5" .

@46'- Gray SILTSTONE, 15" dip, internal ly loaded, broken, 6" thick,@46.5'- Light brown medium grained SANDSTONE, cemented and hard,1 0 ' d i p .

@48' - Gray SILTSTONE on channel margin with 40' dip, loads/burrowsin lower contact, upper contact lost.

@48' - Light brown medium grained SANDSTONE, sparse bedding(darker fi ner grained and biotite-rich horizons), dipping 20-25', denseand hard.

Total Depth - 51'

100%

45

79Yo

50

55

60

65

70

75

BO

85\DDITIONAL COMMENTS:

Logged by: SR Geolabs-Westlake Village PLATE B1,2

SUBSURFACE DATA LOG OF BORING 82

CLIENT: Tone Yee PROJECT: Andora Road W.O.:8725LOCATION:Lot7 ELEVATION:1123' DATE: Bl12103R G TYPE: Cont. Core HAMMER WEIGHTS: DROP:

N U B M Recov. DESCRIPTION ATTITUDES0 Slough, weathered, not collected.

@6'- Dark yellow massive very coarse grained SANDSTONE, abundantvery small pebbles, very dense and infriable but weathered and poorlycemented.@7.5' - Steep fracture with oxidized coating, 60', spiral fractures from9.5-1 1', harder with depth,@11.5' - Reddish black mica rich medium grained SANDSTONE,shattered in core and pieces are friable, includes oxidized fractures,possible bedding at t20".@12' - Channelled and eroded silty fine grained SANDSTONE to verycoarse SANDSTONE, stratigraphy obscured by numerous concretions,rock generally light brown mottled in light gray, pale brown, and yellowishbrown.@15'- Weak yellowish brown very silty very fine grained SANDSTONEwith abundant white carbonate veinlets, poorly preserved in core, about3/4" thick, dipping at25'.@15'- Interbedded brown SANDSTONE and gray MUDSTONE toCLAYSTONE, very broken along 20-25" bedding, may have somepolished surfaces in claystone near top of unit, but claystones usuallyburrowed and loaded.@19.75'- Light brown thinly bedded medium grained SANDSTONE,bedding at 15-20', cemented, dense and hard, last 5" at 20,5-21'discarded to flt in box.@22' - Lost circulation, sparse beds of gray rip-ups, notable striationsalong sandstone bedding at 25.5'are barl</leaves,@25' - Massive light yellow very coarse grained SANDSTONE,cemented and hard.

Total Depth - 31'

5

100To

10

68%

1 5

80Yo

2C

100Yo

25

?%

30

35

40

45\DDITIONAL COMMENTS:

Loggedby: SR Geolabs-Westlake Village PLATE 82

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President Asset Group Unconfi ned Compression Testing January 27,2009w.o.8725

CoreDiameter

(in)

Cappedlength

(in)Area(in^2)

Forceat

Failureflb)

CompressiveStrength

{psi)

Breakangle

(deorees) LitholoovB 1 @ 1 6 . 5 2.47 4.95 4.79 29715 6201 70 pebblv ss81@26 2.47 5 , 1 5 4.79 32578 6799 70 M S S

81@44 2.47 4.98 4.79 22094 4611 60-70 M S S

81(a50 2.47 E , 4 4.79 24259 5063 60-70 M S S

82@,12 2.47 4 . 8 4.79 8059 1682 60-70 css82@27.5 2.47 4.79 20994 4381 70 css

Plate UCT

President Asset Group January 27,2009w.o.872s

Br @ r6.s ft.

Br @26 ft .

Plate UCT P.l

President Asset Group January 27,2009w.o.8725

Br@44f t .

Br @s}f t .Plate UCT P.2

President Asset Group January 27,2009w.o.8725

82@r2f t .

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Plate UCT P.3

President Asset Group Hoek-Brown Parameters

Analysis of Rock Strength using Roclab

January 27,2009w.o.8725

ouu II

sao i

Hoek-Brown Glassificationintact uniaxial comp. strength (sigci) = 600 ksfGSI = 80 mi = 17 Disturbance factor (D) = 0intact modulus (Ei) = t65OOO nttmodulus ratio (MR) = 17!

Hoek-Brown Criterionm b = 8 . 3 2 2 s = 0 . 1 0 8 4 a = 0 . 5 0 1

Mohr-Goulomb Fitcohesion = 27.296 ksf friction angle = 56.89 deg

Rock Mass Parameterstensile strength = -7.8'13 ksfuniaxial compressive strength = '197.256 ksfglobal strength = 271.594 ksfdeformation modulus = 145257.39 ksf

20 40Normal stress (ksf)

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President Asset Group January 21,2009w.o.872s

APPENDIXA

SLOPE STABILITY AI{ALYSES

ELOPE STABI LITY ANALYSIS87 25 PRES I DENT ASSET/CHATSWORTH

TSECTION 4-4'PROPOSEDPSEU DOSTATI C/CI RCULAR

1O MOST CRITICAL SURFACES

File Name: 4-4'. Proposed.Seis. Hoek-BrownFile Location: C:\8725 Slope Stabil ity

\4-4'.Prooosed.Seis.Hoek-Brown.sli

Global Min imumsMethod: spencerFS :10 .792900Center: 246.513, 1 380.330Radius: 264.916Left Slip Surface Endpoint: 7.437, 1266.211Right Slip Surface Endpoint: 31 1 .918, 1123.615

KcF*^*,* ,1

f t

Icryql

1

|SLOPE STABILIry ANALYSISg7 2si p nrs r o rNT ASSET/c HATSWo RTH

i srcttoN 4-4'PRoPosEDPSEU DOSTATIC/C IRC U LAR

ALL SURFACES

File Name: 4-4'.Proposed.Seis. Hoek-BrownFile Location: C:\8725 Slope Stability

\4-4'. Proposed. Seis. Hoek-Brown. sli

Global MinimumsMethod: spencerFS: 10.792900Center: 246.513, 1 380.330Radius: 264.916Left Slip Surface Endpoint: 7.437,1266.211Right Sf ip Surface Endpoint: 311 .918, 1123.615

I

-200

President Asset Group 87254-4' .Proposed. Seis.Hoek-Brown

S/ide Analysis lnformation

Document Name

File Name; 4-4'. Prooosed.Seis. Hoek-Brown

Proiect Settinqs

Project Title: 8725 President AssetGrouplAndora/Chatsworth

Failure Direction: Left to RightUnits of Measurement: lmperial UnitsPore Fluid Unit Weight: 62.4lblft3Groundwater Method : Water SurfacesData Output: StandardCalculate Excess Pore Pressure: OffAllow Ru with Water Surfaces or Grids: OffRandom Numbers: Pseudo-random SeedRandom Number Seed: 101 16Random Number Generation Method: Park

and Mi l ler v .3

Analvsis Methods

Analysis Methods used:Bishop simplif iedSpencer

Number of slices: 25Tolerance: 0.005Maximum number of iterations: 50

Surface Options

Surface Type: CircularSearch Method: Grid SearchRadius increment: 10Composite Surfaces: DisabledReverse Curvature: Create Tension CrackMinimum Elevation: Not DefinedMinimum Depth: Not Defined

Loadinq

Seismic Load Coefficient (Horizontal): 0.2

Material Properties

Material: Kc Hoek BrownStrength Type: Generalised Hoek-BrownUnit Weight: 130 lb/ft3Unconfi ned Compressive Strength (intact) :

600000 psfmb:8.32221s: 0.1 08368a:0.500593Water Surface: None

GlobalMin imums

Method: bishop simplifi ed

FS:10.767100Center: 246.51 3, 1 380.330Radius:264.916Left Slip Surface Endpoint: 7.437, 1266.211Right Slip Surface Endpoint: 31 1 .918,

1123.615Resisting Moment=3.58588e+009 lb-ftDriving Moment=3.33042e+008 lb-ft

Method: spencerFS: 10.792900Center: 246.513.'1 380.330Radius:264.916Left Slip Surface Endpoint: 7.437,1266.211Right Sl ip Surface Endpoint: 311.918,

1123.615Resisting Moment=3.5945e+009 lb-ftDriving Moment=3.33042e+008 lb-ftResisting Horizontal Force=1.18182e+007 lbDriving Horizontal Force=1.095e+006 lb

Valid / Invalid Surfaces

Method: bishop simplifiedNumber of Valid Surfaces: 4148Number of Invalid Surfaces: 703Error Codes:Error Code -102 reported for 1 surfaceError Code -103 reported for 7 surfacesError Code -106 reported for 14 surfacesError Code -107 reported for 9 surfacesError Code -1 1 1 reported for 133 surfacesError Code -1000 reported for 539 surfaces

Method: spencerNumber of Valid Surfaces: 2834Number of Invalid Surfaces: 2017Error Codes:Error Code -102 reported for 1 surfaceError Code -103 reported for 7 surfacesError Code -106 reported for 14 surfacesError Code -107 reported for 9 surfacesError Code -108 reported for 468 surfacesError Code -111 reported for 979 surfacesError Code -1000 reported for 539 surfaces

Error Codes

The following errors were encountered duringthe computation:

-1O2 = Two surface / slope intersections,but resulting arc is actually outside soil region.

-103 = Two surface / slope intersections,but one or more surface / nonslooe external

polygonintersections lie between them. This usually

occurs

President Asset Group

when the slip surface extends past the bottomof the

soil region, but may also occur on a benchedslope model with two sets of Slope Limits.

-106 = Average slice width is less than0.0001 " (maximum horizontal extent of soil

region).This limitation is imposed to avoid numerical

errorswhich may result from too many slices, or toosmall a slip region.

-107 = Total driving moment ortotal driving force is negative. This will occurif the wrong failure direction is specified,or if high external or anchor loads are appliedagainst the failure direction.

-108 = Total driving momentor total driving force < 0.1. This is tolimit the calculation of extremely high safetyfactors if the driving force is very small(0.1 is an arbitrary number).

-1 11 = safety factor equation did not converge

-1000 = No valid slip surfaces are generatedat a grid center. Unable to draw a surface.

List of All Coordinates

Search Grid92 1248478 1248478 157992 1579

External Boundary430 1127364 1127361 1124308 1124308 1134301 1134301 1144275 1169267 1169241 1195233 1195208 1220200 1220181 1239180 1238177 1233176 1230173 1228168 1225163 1224159 1223151 1224

4-4' .Proposed. Seis.Hoek-Brown

140 1227131 1230114 123591 124168 124735 12580 12690 1050430 1050

SLOPE STABI LITY ANALYSIS87 25 PRESI DENT ASSET/C HATSWORTH

SECTION 4-4' PROPOSEDSTATIC/CIRCULAR

1O MOST CRITICAL SURFACES

File Name: 4-4'. Proposed. Hoek-BrownFile Location: C:\8725 Slope Stability

\4-4'. ProPosed. Hoek-Brown.sli

Global MinimumsMethod: spencerFS: '15.188600

Center: 304.303, 1264.239Radius: 140.325Left Slip Surface Endpoint: 169.344,1225.803Right Slip Surface Endpoint: 3O7.677, 1123-955Left Slope lntercept: 169.344 1225.803Right Sfope Intercept: 3O7 .677 1 133.615

-200 -1

S[].OP E STAB I LITY ANALYSI S87 25 PRES I DENT ASSET/C HATSWORTH

SECTION 4-4' PROPOSEDSTATIC/CIRCULARALL SURFACES

File Name: 4-4'.Proposed.Hoek-BrownFile Location: C:\8725 Slope Stabil ity

\4-4'. Proposed. Hoek-Brown.sli

Global Min imumsMethod: spencerFS :15 .188600Center: 304.303, 1264.239Radius: 140.325Left Slip Surface Endpoint: 169.344,1225.803Right Slip Surface Endpoint: 3O7.677, 1123.955Left Slope lntercept: 169.344 1225.803Right Slope Intercept: 3O7 .677 1133.615

i t lssl

&L - ' - - - - - - - - ' - r i0 100 200

President Asset Group 87254-4' .P roposed.Hoek-Brown

S/ide Analysis Information

Document Name

File Name: 4-4'. Proposed. Hoek-Brown

Proiect Settinqs

Project Title: 8725 President AssetGrou p/Andora/Chatsworth

Failure Direction: Left to RightUnits of Measurement: lmperial UnitsPore Fluid Unit Weight: 62.4lblft3Groundwater Method: Water SurfacesData Output: StandardCalculate Excess Pore Pressure: OffAllow Ru with Water Surfaces or Grids: OffRandom Numbers: Pseudo-random SeedRandom Number Seed: ' l 01 16Random Number Generation Method: Park

and Mi l ler v .3

Analvsis Methods

Analysis Methods used:Bishop simplif iedSpencer

Number of slices: 25Tolerance: 0.005Maximum number of iterations: 50

Surface Options

Surface Type: CircularSearch Method: Grid SearchRadius increment: 10Composite Surfaces; DisabledReverse Curvature: Create Tension CrackMinimum Elevation: Not DefinedMinimum Depth: Not Defined

Material Properties

Material: Kc Hoek BrownStrength Type: Generalised Hoek-BrownUni tWeight : 130lb/ f t3Unconfined Compressive Strength (intact):

600000 psfmb:8.32221s :0 .108368a: 0.500593Water Surface: None

GlobalMin imums

Method: bishop simplif iedFS : 15 .161600Center: 304.303, 1264.239Radius: 140.325Left Slip Surface Endpoint: 169.344,1225.803

Right SIip Surface Endpoint: 3O7.677,1123.955

Left Slope Intercept; 169.344 1225.803Right Stope lntercept: 3O7 .677 1133.615Resisting Moment=8.0771 5e+008 lb-ftDriving Moment=S.32737e+007 lb-ft

Method: spencerFS: 15.188600Center: 304.303, 1264.239Radius: 140.325Left Slip Surface Endpoint: 169.344,1225.803Right Slip Surface Endpoint: 307 .677,

1123.955Left Slope Intercept: 169.344 1225.803Right Slope Intercept: 307.677 1133.615Resisting Moment=8.091 52e+008 lb-ftDriving Moment=5.32737e+007 lb-ftResisting Horizontal Force=4.46341 e+006 lbDriving Horizontal Force=293866 lb

Valid / Invalid Surfaces

Method: bishop simplifiedNumber of Valid Surfaces: 3894Number of Invalid Surfaces: 957Error Codes:Error Code -102 reported for 1 surfaceError Code -103 reported for 7 surfacesError Code -106 reported for '14 surfacesError Code -107 reported for 104 surfacesError Code -108 reported for 160 surfacesError Code -111 reported for 132 surfacesError Code -1000 reported for 539 surfaces

Method: spencerNumber of Valid Surfaces: 2946Number of Invalid Surfaces: 1905Error Codes:Error Code -102 reported for 'l surfaceError Code -103 reported for 7 surfacesError Code -106 reported for 14 surfacesError Code -107 reported for 104 surfacesError Code -108 reported for 727 suffacesError Code -1 1 1 reported for 513 surfacesError Code -1000 reported for 539 surfaces

Error Codes

The following errors were encountered duringthe computation:

-1O2 = Two surface / slope intersections,but resulting arc is actually outside soil region.

-103 = Two surface / slope intersections,but one or more surface / nonslope external

polygonintersections lie between them. This usually

occurswhen the slip surface extends past the bottom

of the

President Asset Group4-4' .Proposed.Hoek-Brown

soil region, but may also occur on a benchedslope model with two sets of Slope Limits.

-106 = Average slice width is less than0.0001 * (maximum horizontal extent of soil

region).This l imitation is imposed to avoid numerical

errorswhich may result from too many slices, or toosmall a slip region.

-107 = Total driving moment ortotal driving force is negative. This will occurif the wrong failure direction is specified,or if high external or anchor loads are appliedagainst the failure direction.

-108 = Total driving momentor total driving force < 0.1. This is tolimit the calculation of extremely high safetyfactors if the driving force is very small(0.1 is an arbitrary number).

-111 = safety factor equation did not converge

-1000 = No valid slip surfaces are generatedat a grid center. Unable to draw a surface.

List of All Coordinates

Search Grid92 1248478 1248478 157992 1579

External Boundarv434 r27364 1127361 1124308 1124308 1134301 1134301 1144275 1169267 1169241 1195233 1195208 1220200 1220181 1239180 1238177 1233176 1230173 1228168 1225163 1224159 1223151 1224140 1227131 1230

11491683500430

123512411247125812691 0501 050

President Asset Group 5

REFERENCES

January 27,2009w.o.8725

City of Los Angeles, January 28,2005: Geology and Soils Correction Letter for VTT 53426,Lots l-43 and Four Open Space Lots, 9503 Andora Avenue, City of Los Angeles, Califomia.Log No. 46557.

Department of Conservation, Division of Mines and Geology, 1997: Seismic HazardZoneReport 06, Seismic Hazard Zone Report for the Calabasas 7.5-Minute Quadrangle, LosAngeles and Ventura Counties, Califomia.

Hoek, E.2006: "Practical Rock Engineering",< http://www.rocscience.com/hoelc/pdf/Practical_Rock_Engineering.pdf) (January 22,2009).

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GEOLABS - \ME STLAKE VI L LAGE

                                         

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