2.0 Landslide Configuration and Characteristics 2.0 LANDSLIDE CONFIGURATION AND CHARACTERISTICS
2.1 Configuration
The active slide involves approximately 200 acres of ground fronting the Pacific Ocean
on the southern margin of the Palos Verdes Peninsula, California. The approximate lateral
extent of the main body of the active PBL and key features within the slide are shown with
1995 topographic contours in Figure 2.1. Movement of this slide has been continuous
since it was reactivated in 1956. Portions of PBL have been displaced seaward by up to
800 feet over the past 40 years, causing distress to a major roadway, Palos Verdes Drive
South (PVDS). The slide averages approximately 2700 feet in width and extends nearly
3,500 feet inland from its toe along the shoreline. The ground elevation at the Landward
margin of the active failure is on the order of 450 feet above sea level. The ground
surface has an average slope of 7° from the head of the slide to the shoreline. The most
• distinguishable topographic features within the failure include a 10 to 20 foot deep canyon
(Portuguese Canyon) which transects the failure in a north-south direction (Figure 2.1),
and an approximately 80-foot high bluff along the beach near the toe of the failure.
As shown in Figure 1.2, the active landslide can be characterized by dividing it into four
separate Subslides based upon movement patterns and geologic and/or geomorphic
features. From a geotechnical engineering perspective, the stability of the Subslides is
interdependent. In the order of generally decreasing stability or increasing displacement
rate, these include the Landward, West-Central, East-Central, and the Seaward Subslides.
Due to their higher movement rates, pull-apart zones are generally present along the
upslope boundaries of the Seaward and East/West Central Subslides. The Landward
margin of the active landslide is distinct and defmed by material sliding down a ramp,
thereby, surcharging the slide. The eastern margin of the landslide is defmed by a zone
of shearing along the base of the adjacent ascending ridge. The western margin of the
landslide is somewhat less distinct due to the slower rates of movement in this area. A
•
reasonably well defined zone of shearing and deformation is present along the
4
southwestern margin of the active PBL as it is shown in Figures 1.3 and 2.1. The toe of
PBL occurs at the beach.
Since its reactivation became apparent in August of 1956, the rate of movement during the
past 40 years has generally ranged from less than 0.2 to more than 1.5 inches per day
depending on the time and locations. The higher displacement rates have generally been
associated with periods of above average rainfall as will be discussed further in Section 3.
The average rate of movement has consistently been greatest for the Seaward and East-
Central subslides. Vectors representing the approximate magnitude and direction of
movement since the reactivation of the failure are super-imposed on the 1995 site plan in
Figure 2.1. These vectors are based upon reference points discernible in historic aerial
photographs (i.e., houses, roads, etc.) and/or survey data. The positions of some of these
reference points as well as the lateral extent and topography of the general area are shown
on the topographic maps of 1955, 1984, 1986, 1987, and 1988, presented in Figures 2.2
• through 2.6. The approximate boundary of the Phase 1 (1984) and Phase 2 (1988)
regrading as a part of the POC implemented by the City are shown in Figures 2.4 and 2.6,
respectively.
2.2 Slide Characteristics: An Overview
Cross sections through the active landslide based upon 1995 topography are presented in
Figures 2.7 through 2.9. The alignments of these cross sections are shown in Figure 2.1.
One of the important characteristics of PBL, as can be seen from these cross sections, is
that the existing ground surface is nearly parallel to the underlying failure surface. As a
result, the thickness of the active failure is relatively uniform and averages approximately
100 feet above the primary sliding surface. The average ratio between length (or width)
of the slide to thickness is about 30 to 1. The total volume of soil and rock contained
within the failure is on the order of 40 million cubic yards while the total mass
(soil/rock/water) is estimated to be about 60 to 65 million tons.
5
Based on the available topographic maps, the ground surface changes which occurred
110 along cross sections C-C' and D-D' between 1956 and 1995 are illustrated in Figure 2.9.
The most prominent changes during this time period include the following:
• The average elevation of the ground surface within the upslope portion of
the failure decreased by approximately 50 feet.
• The average ground surface elevation near the original toe of the bluff
increased by approximately 75 feet.
• The high tide line (r. elevation +5 ft. MSL) was displaced approximately
200 to 300 feet seaward.
Where it has not been altered and maintained, the surface of the ground within much of
• the failure is generally hummocky, irregular and locally fissured due to (1) the translation
of the mass along an undulatory failure surface; and (2) secondary sliding or differential
movement induced by stress redistribution within the slide mass. Consequently, surface
drainage within the landslide is generally poor and difficult to maintain. As shown in
Figure 2.1, there are three primary canyons which discharge concentrated surface run-off
into the landslide area during periods of high rainfall. These canyons include Portuguese
Canyon on the west, Paintbrush Canyon on the east and Ishibashi Canyon located
approximately mid-way between these two. Infiltration of the run-off conveyed through
these canyons is a source of recharge for the groundwater within the landslide.
•
6
$ 11
1
_ 4111W .i \F
Iy ,y s6o� .. '51'o
wilitil •• fie 5 /w
i*011.110 .i' llikiller 1'6' •:.
'11111110 left
iiiikt °?• :96-3
SECONDARY 69- ,
III
to
42o •O W-2 SLIDE MARCH 1995 •
` SECONDARY
SLIDE MARCH 1995 :96-4 \ `
12 ps 9�,
W PT 8 • • , •
S►yEE� • 8 04111114% .,/it). 1N EE w 1�`II
696-7
11, \-a ,—N4,020,000 WX\1r �=e QN4,020,000)
/ , W6A2 •••••••••7B' B96-0 B
1 IlfPBS-7 '
40 LANDWARD SUBSLID�: 4 •B96-13
/ 41 *WN E'
*� W6: WSC ::8r WSE. :YA-3
• B96 11696-16 4k. / p l
4P. 0 ♦m___m PBS-6 F U T&JJ
♦ t! NB96-17 at
/ • I ;• •V /32 W2C 32•
3.• I :96-1 .6 -2
•WSW ♦ 96W-1\
i V • 696-2
2D J&4 W4E 5 \\
340 <. I • •PBS-11
•CC B96-1:
I
•
rye
•PBS-5 ;
^
f • � W !�. PBS B88-9
Me 4
,0 �„ , ` A 300- 1 : .PW_6
F I
�QQ1111111r ���.. M 2 r Portuguese Can ••-
F• la • QEF leo 1, I 00Y
.1
' �j illiNk
4 ♦ • , , BB B96-11
Oliffitill.
• 1
W-3 .17r •
8• 0PBS-4 BYA-1,, •696-10
110
2 WLT
��8 jN 1 •B96-1 •S1K
11 C''''''''."-----24-0 • 1
• . W2H
r\. ) V� �, i•• •K •WI1 WPBS 9
24� , � EAST-CE TRAL SUB ' LIDE
•DW
2 P /
ir
--
/--A-1 ��p I ��Cy�c� flcoi OPBS-to WI,
•W6K �PJ.y,` yWF •
.LI.
WLI
• !`4!\-:-/t—N--- x
J WCH PBS-2 •KK :• • WI2 a`b
WEST-CENTRAL SUBSLIp
milpr
PALOS •
a VERD;S .. ..
...`. • • wls
I-10 • DR/VESOU/y �� N4,018,000
N4,018.••• 5• I usiiiiir • E • Z
'...... DD • PBS-1
a .. [3k,
W2L S •
• - � �—', •W2M • 200
\I •
�'• C) F-1,2 . GG •
• ‘11:1000
1.•
DW- \ • 1e•
A&2
• C-9,10 6 C-11 E-3, ili •
•• • •• -1C-2
• C-12 •B-A,1,2 A-A 1.
H
6� • G&7 A-2
4
eo
1 :I ,--1 1 i 11:
3 / SEAWARD SUBSLIDE -9
DW-1 . L
( 1 6,3j-J ''74:140, A
• . •
DW-10
DW-9 �,P
•0*,1711111111.MdPB-2 - - ,
• 89
PACIFIC OCEAN `. .p01
A' •
LEGEND , 4
�B-1
TOPOGRAPHIC CONTOURS BYA-1 O PIEZOMETER 1NSTAI I Fr)BY BYA 1996 SI
IN FEET(MSL) B-96-180 1996 SOIL BORING D'
.•...`..0 APPROXIMATE SLIDE BOUNDARY PB-1 • BULK SOIL SAMPLE , H
TOE OF SUDE PBS-2• BORING DRILLED IN 1996 `
,,. -- •..14, DIRT ROAD W4E• WELLS MONITORED FROM 1984-96
r..l-•••••` ROAD WCH• WELLS MONITORED FROM 1984-86 0 300 600 FEET
B88-90 1988 BORING i i (Base Map, 1995)
ip BUILDING
96W-lO 1996 BORING BING YEN & ASSOCIATES, INC.
MOV MENFV CTORSBASEDON p❑❑❑ SUMMARY OF KEY FEATURES
AERIAL PHOTOGRAPHS OR SURVEY BB• 1956 57 BORING ■■ ■■ Geotechnical&Environmental Consultants,Established 1979
OF DISCERNIBLEFEATURES,SCALE AND THE 1995 TOPOGRAPHIC
F-1• 1956-57 CAISSON PROJECT NAME: PORTUGUESE BEND LANDSLIDE MAP OF LANDSLIDE
PROJECT NO:G-940989 I DATE: MARCH 1997 FIGURE 2.1
1111111111% .
WO
o .II a \ 660
s
w 640
O •DW-2
q V\ S..
ipi,,,,_
10111
i-N.., c_, ,,,
54*
,--(..„ :•• *i.
SwFf reAr'P' allik
..
°cb EE•
'a
•9 R
—N4,020,000
__ 410/0 P .
N4,020,•••
•8 T&JJ•
• III ■ 400
al
( PIN \ ___.2
.- .4
0
IIII " ,e 3-• -GY`pta
1
e •U ••
1;14/GER/eel —l •v
i
3,43 i J&4 ca
•L r
i' � Portuguese Canyon
i
1
•CC
340- 71111IIIIIC V\ -
.,,,,,,iii jii )
PPER�R ! 6 _)
milli iv
s -• •• •s
2c>✓ •Y •:.•• 2:• •W
3 •DW-3 •
BB
240.,______ 260--A---(
•AA
+ •N elFF2
Iiir
CHERRY, n.��. •x
_]1°:00i__/° 1 illh °1111•IIII • se
4,
.. ,,,,,i, a,
KK -<"0�
iIIIIIIIz
•1
ill-1 20� •I p
—N4,018,000 •5 •DD A[�S • Z
. �FSDR/V N4,018,0&&
:• `� t:• - ESoUTH
4104--dirt "A• •
1-• 1111 F'
DW-7-----I••
1
1• ,, 002 •
, eb. • 220
1,2
DW-1 &2 Ito
4'1(46 C-11 A �-----\____:.,:,,\_, .
E-3,4 C-1,3, 2 B-A,1,2
20
•H •G&7 C-12 ----A-2 •:9m�
DW-4 •• -■ 44( 0 3 L
Portuguese Bend Club. 44
•
* -13 ‘\--)6) •
DW-10 lJ
,...„) _
PACIFIC OCEAN .6,0 ''''----41111114
.rDW- n•
•DW_8 DW-12 ,1 tatt
l
11111P '
LEGEND
•
100- TOPOGRAPHIC CONTOUR X• 1956-57 BORING
IN FEET(MSL)
DIRTROAD F-i• CAISSON 1956-57
ROADS
1111 BUILDING
0 300 600 FEET
0rir BING YEN & ASSOCIATES, INC.
:oe Geotechnical$Environmental Consultants,Established 1979 PRE-1956 LANDSLIDE GROUND
FEATURES AND POST LANDSLIDE
PROJECT NAME: PORTUGUESE BEND LANDSLIDE 1956-57 FIELD ACTIVITIES
(Bose Map,1955) PROJECT NO:G-940989 I DATE: MARCH 1997 FIGURE 2.2
...,_____________ 48cr,....r'------------------ —..,/j p -- - ,-04, ,,0„,z)i ;.1\
______, _ eics,
' N c6°
460._____1:_ - met moo,
Lu
4 • 1
C iiiii -.• `tbN f
.(
�'4y•a /�3.•
4
N4,020,000
N4,020,000-
4 \
111 t SO '.•,.,
..,/,,f
/ :.
)- ,..
..
--"---'--
0 3
3 • f..,•
il
Ye?tit)", 4IP ;-24,1)
lialli
'e6\------) *
\ (0
411111 .
2.• . 4.11111, -------________ ____IL
o � es
II;
2 • ____, 1
:-[-- .7
4
�1
CHERRymu LM1-----'2
••
N4,018,000 1 • N4,018,
/ rD
PALOS VERDES DRIVE SOUTH
°—L----Z-MCI
140 1 • 1 \C.. :1>
•
b 1 1 �
O L__2...'j--?
,,,, 2 ---,r------------- — , ? 4/16-1.:c252.4:1,s.,,___e_2,,___2___o__
Z.---,_ ___) L-40 C._,r. NI
t fes,
4o
PACIFIC OCEAN
LEGEND
180— TOPOGRAPHIC CONTOURS
IN FEET(MSL)
fl..".— — DIRT ROAD
----'`"''''''' ROADS
• BUILDING 0 300 600 FEET
LOA BING YEN & ASSOCIATES, INC. TOPOGRAPHIC AND SURFACE
mom Geotec nlcal&Environmental Consultants,Established 1979
FEATURES OF PORTUGUESE BEND
PROJECT NAME: PORTUGUESE BEND LANDSLIDE LANDSLIDE AS OF 1984
(Base Map,1984) PROJECT NO:G-940989 DATE: MARCH 1997 FIGURE 2.3
*4 /41‘114Nk ..
w
W
440 41g%1 '4'
eh i9
kr .42,
4,,„ IF) *. I
sit
%4 'P, i '•,.
us
3•• s
S •
fg .cf:r0 1\1:111H1si
�3.•FTAYQO W6®
—N4,020,000
• `•
N4,0
2 0,000
-
if ..
W6A210 III.\1 •
•WNc\--\ AC \.
)___ :.
014 10'
G
/ flW2C 320 3� �L
3
W2D
•W4E
Ili,
"3 ®W2F
Aillk"IP :13...
\ •• :•
QR
OC't IgE z:• Zbo
2:. F:� e
FF
�O
•
WLT
2.,
17d 'LA
2H /
W2M 490,_i 7 v
\------240----} I
2 • 160
140,/ I:
1
W6K
®WLI
\ 180 ®WCH \
...--- ----...,.1 ..iiimiiA (iss
J '• o CHERRY HILL •
0O 80_ 1
180
N4,018,000, r N4,018,00()
iii/ 1 It
W2L
.4 PALOS VERDES DRIVE SOUT
16•
1443--- /1:• �-
(--- Q R\ s„,_\,, ,,,,,„..„,,, • -P.6. ..,.../...
...___ bo
iN
cc, . c.,„j.. ...,.2
7 1...- 4).15
40
________------ • • lop\ Z7ts..,C .:041
l PACIFIC OCEAN i/t/
LEGEND
- TOPOGRAPHIC CONTOURS
l'Ill. 4IP
IN FEET(MSL) WCH® WELLS INSTALLED BETWEEN tilik
1984 AND 1986
•+•.+.. DIRT ROAD •
'"�"-"� ROADS W6K • WELLS INSTALLED BETWEEN
1984 AND 1986 FOR WHICH
GROUND WATER LEVEL DATA
1111 BUILDING
IS AVAILABLE TO 1996
BOUNDARYFOR PHASECa
0I 300 600 FEET 0�
GRADING
o■oBING YEN & ASSOCIATES, INC.
„IAGeoiechnical&Environmental Consultants,Established 1979 DEWATERING AND PHASE 1
GRADING BETWEEN 1984-86 SHOWN
PROJECT NAME: PORTUGUESE BEND LANDSLIDE ON TOPOGRAPHIC MAP OF 1986
(Base Map, 1986) PROJECT NO:G-940989 I DATE: MARCH 1997 FIGURE 2.4
L------._ _____ cz8_____--•:. •-- -------N,\.,, 1- I. 1." 41-14‘4144444rteijoi c§)-)T6
LL LL w
`-------) A
*/* iihk, ,--Q2p
.,
s
sit 4 �s •
'PO1
1.:
sif
—N4,020,000
1 N4,020,000
I
lir
....
•
.,
0,41
i,
0 G
S.--3'4' ) 32•
•• /(—
\\_ Portuguese Canyon
'. iigkji ,, \ Vy
ry' cF ! ,
--------1_ 00.
D ''
. .
Fv.
1:0 \ ierkiiit
))V (r ,
4111 24• �� t _.'9 _ 180
.. . f 4
77 --'.\'D
l
ACOS VE?D ESOU
N4,018,000 b
ESOR/� N4,018,000
TH
r iir \'
/
so
160
180 C___\.
/
1 Ile ---- -----"n / :
f4(1-',-----
:•
720 •`
i- .. 14 i:or; _:22°-
\ I
\il, -\,1-.•
iso
s
PACIFIC OCEAN t 411
4,,..„
LEGEND
- TOPOGRAPHIC CONTOURS
IN FEET(MR)
- - - DIRT ROAD
ROADS
ipi BUILDING
0 300 600 FEET 0
MEEBING YEN & ASSOCIATES, INC.
boeGeotechnical&Environmental Consultants,Established 1979 TOPOGRAPHIC AND SURFACE
FEATURES OF PORTUGUESE BEND
PROJECT NAME: PORTUGUESE BEND LANDSLIDE LANDSLIDE AS OF 1987
(Base Map, 1987) PROJECT NO:G-940989 DATE:MARCH1997 FIGURE 2.5
O § ),,\
•• 44ri
14. w
w 440 A� 1♦
ilk 164 ik
1
1/4 4.20 * ♦
‘-rY\''Fi'lk„.
•
•
S r •W PTAllik ®88-4 ♦
A,5 g
1
—N4,020,000 lb. VO '
`390 N4,020,000-
"R * '?9'
Ihr
ill 440. ,, -,
SIr •• B88-519 0,
GPC
.kC \
<39 3 \\360
340 Aiii , ` C \
�� u Portuguese Canyon q?
J, ®B88-9
13 • ...i. ;•
N 1# i.
( 44000
ccF-
� ill l'`'?'
2s
0 7
240
delli
-------...„ / itit
„ //
411
�U
1( ;:i 4
7 k(,,,
1:•
\ . 16oi ' '
6f4 01;
/--7 81
L.
N4,018,000_180 Z' 1,7 vex
ppb
N4,018,000J
our, g(
J
21, ,, .,00
I • 159u. .,„
:•
i
160
1-•
7.
is, 1
r__________._.---100—"D
' 0 /
. , ef
69 J •
X44
40
• • ,VIStliciP4p ,
20il .
PACIFIC OCEAN
LEGEND
--100 TOPOGRAPHIC CONTOURS
IN FEET(MSL)
_, PIPE
11111
'"T-"-''.."' ROADS
IIII BUILDING
0 300 600 FEET• 0.
WPT LOCATION OF PEPPERTREE \
I
DEWATERING WELL
®B88-4 1988 BORINGS mor BING YEN & ASSOCIATES, INC.
AREA OF PHASE II GRADING h�e cieO��" &Environmental Consukents,Estedished 1979 1988 TOPOGRAPHIC MAP AND
PROJECT NAME: PORTUGUESE BEND LANDSLIDE PHASE II GRADING
(Base Map, 1988) PROJECT NO:G-940989 DATE: MARCH 1997 FIGURE 2.6
CD th ,
: it
t
K
�a ��� ELEVATION IN FEET FROM MEAN SEA LEVEL ELEVATION IN FEET FROM MEAN SEA LEVEL
� /
�� ;T a a a a 0.a
o � aIco
a
n
ti B96-3 (Projected410W) 0
- 0 y �/�CI) {
t-,0
y
0Q y
w Q Q -7 B96-9 (Projected 90'E)
—
w
o c `^^/
r
o '
W 0-
0
tiO c " �
B
96-5 (Projected-
`D � o
y 0a
V )T 1 B96-7 (Projected 120W)
) y o
�/ — P(Projected 100W) a
��DW-2(Projected 230E) o
^ - PBS-12 (Projected 10'W)
=� - 0 (Projected 35C(E) /H (Projected 240'E)
O
a) .O
a o ,B96-13 (Projected 170'E)
co _EE (Projected 210''E)
B96-14(Projected 20E)
I I
I 1 ( Co
o w o i B96-16(Projected 40W)
ao o jj U (Projected 110'W)
fli
N W2C (Projected 150'E)
o
D B96-15(Projected 90')
w o,
0 a 0 B96-18 (Projected 220W)
l) I I I 1 I ) 11'1 t
1 44
o 3 c cr. 1 1 ` W2F (Projected 100'W)
7 m o- y _ o
cos c Cl) .
0 Q Q ti I I PBS-8(Projected 190'E)
0 3 m i�S(Projected 200'W)
m w— o
m0 Q o a
0
n� 'R
0 'n
0 - 8e- 0 1 B96-11 (Projected 250'W)
; ,
o o u Z D Q o .l
�. m D a Q ( /B96-4(Projected 220 WJ )! Y(Projected 270'E)
v ` c n - i
N N Y m 8— ID N 0 N Ox ;1 I
Q m' m z o c m` 3 W2H (Projected 300W)
m 0 c Z mm
° � m Occ C) N a0
51 J m 2 Z o 3 °c
m (1 Q.
A(Projected 200'W) -I ,po N
■rA P O
)1 A
O
O O ❑❑m a
''' ''" -,.,,,t,
-4 p, .QIII B96-12(Projected 170W) N
1 A X Proected 60'E
Z Z - PBS-7(Projected 70W) o ( ) )
0 Ca
{
O P' 8 Z PBS 10 (Projected 50'W)
o ^ f 1
!�/ a I I ( 1 1 I R1
`o j
R. m o o y
m o' Z _ o KK (Projected 80'E)
cc m ] M o C Q
R"
z0-s
zo 0 °c _, DD (Projected 10'W)
o -151 cn Ait> g 0 PVDS
/�� a a
rn j �/ o a (7)C
A xs,
/� o ; I i I � o— c 0
D t —I ( 1 o O Q O
n N °
I. Qc
= y.
C.4 _
y
z y - R I'
V rp
I co (7 a , g A&2 (Projected 80'W)
CD 0.)_ 0
896-5(Projected 300 Co— C-1 (Projected 50W) C-2 (Projected 50W)
(' o /Q 696-8(Projected 90W) o
C-3(Projected 50W)
c
O
_ c B96-7 -
D 0 D (Projected 70'W)
11 n Q m I G&7 (Projected 400'E)
m A a
70 11 Z o— a o DW-10 (Projected 290'W)
0 m DW-4 (Projected 410'E)
y
m m f‘ c)
T - 0 0(Projected 240'E) o i/ 2
Z O , a DW-8(Projected 400'W)
0 Z — 896-14(Projected 90W) a, to
D o — 896-13(Projected 80E( 0 o
T
T (
D
,,
o r , ,
( r a a
°° o( I I o a
a a a
^T_
A ELEVATION IN FEET FROM MEAN SEA LEVEL ELEVATION IN FEET FROM MEAN SEA LEVEL
m
N
•V
kCD
/T
CI) ollt, 4# /
R ' m
a �
ELEVATION IN FEET FROM MEAN SEA LEVEL ELEVATION IN FEET FROM MEAN SEA LEVEL
w w o %, w o
0 0 00 0 0 0 00 0
o
AO 1 B96-6 � 0
� (Projected 90W) 0
P(Projected 300E
)
ON Cl) O
Cl) e 1 v_+ O N
Cl)CA �� /TQ 'A A(Projected 280W)0 ,m2.4,
`Y I o0 O = On
_
O 0
a 96-17 (Projected 150'E) -96 12 (Projected 230'W)
U(Projected 190'E) .PBS-7
Q •6W-1 (Projected 30'E) (Projected 120W)
Q c B96-2(Projected 110'W) m
1 y °6W-2(Projected 30'E) ^ a o
00 4. •BS-i l(Projected 190'W) ` o 0
° R
m B96-18(Projected 90'E) 1 fl
c
PBS-6 imi c
V(Projected 80'W) Q
W2F(Projected 220'E) (D
o r DW-6(Projected 70'W)D. o
2> S (Projected 120'E)
*• &4(Projected 180E)
y CC (Projected 170W)
3 z 0 o r-o W( Projected 200'W)
co 3 o m - m X. ,:96-10(Projected 40'W) - PBS-5(Projected 80'E)
j3'cil o o ��B96 11 (Projected 80'E) 0 1
o c o a m AA(Projected 220W) o
30 Q Q m o ,
O 3 Nj
N 3 O i
a .0° Y(Projected 100'W)
0 0 0 _ a m W2H (Projected 50'
in (D O U,
V7
0 Q N 0 K(Projected 90W) 0 0
c o0
3.3 co !! n Q BB(Projected 140'E)
co m 0 c / i C - !PBS-4(Projected 80'E)
v N
mo o 0 o a
`812. N a N cn D O
D LL (Projected 120W) D a `,.„°
° 3 Z —— `D LI(Projected 230W) Z - — m o ,
2 Z o Q "' o `-° 0 m FF (Projected 250'E)
n Z mm
arri _
O
y -
3 c
A Uro 1 (Projected 160W) m a
O O DAN •BS-1 (Projected 240'W ° (Projected 20'E
ii Ill
( 1 ) o . PBS 3 Pr )
1 .LI' N N P N
P D O O
O m
8
;0 , /Z� DD(Projected 370'E) KK (Projected 150W) o
O o ? 0 - " 2
c t •BS 2 (Projected 90'E) ce
c m m ra CH (Projected 230E) p
w s' Z c- W2M(Projected 150'E) o- DD(Projected 270W)
03 m 3 Ro c GG (Projected 20W) o
Z m
D m N - - 5 (Projected 310'E)
— ocn
(Projected 180W)
O c 0 (Projected 160W)
rn o E 0 ,�, F A- (Projected 140'W) ,.,
R o- I B- (Projected 100'E) o-
y B-1 (Projected 80'E) o
n E m B-2 (Projected 60'E)
= s N - - , F-' (Projected 210'E)F-1 (Projected 230'E)
-_
D -13 (Projected 290W) D-• (Projected 30'E( D-1(Projected 10'E)
V I °° Z D-2(Projected l0'W)
I4:1 n wE-3 'rojected 110'E)
o- ( w o- ' E-4(Projected 80'E)
o �'�► ' o 1 G:,r(Projected 230'E)
. .'W 11 (Projected 220W)
C&" (Projected 270W) _ D -4 (Projected 250E)
-12(Projected 280W)
O D 8(Projected 30'E)
71
O caw
o — wo— /d
CA o
If
m �j
m
D - -
5
Z
N w w
o
` / W o w0 0 _ W O w 0'
Q
0 0 0 0 0 0
Q ELEVATION IN FEET FROM MEAN SEA LEVEL ELEVATION IN FEET FROM MEAN SEA LEVEL
v
v_
^T
2 C
A
n-i
N
cc
C C'
600— —600
1955 Ground Surface
Approximate Limit of Grading -
J
W >y
Ji 1995 Ground Surface - Li
C,v)
z 300— 300 W_ I-
LU
O
LL
W
U-
-
LLI
Example of Strengthened — _
LL1Z
—
u.
Z _ Basal Rupture Surface Z
Z D See Text Sec.6.1 — O
0
,= Basal Rupture Surface Q
Q W
J
W W
W
300 1I ' I ' I ' I ' I -300
0 300 600 900 1200 1500 1800 2100 2400 2700 3000 3300 3600
Cross Section C-C' DISTANCE IN FEET
D D'
600— —600
- -
LL,L++ Approximate limit of Proposed P.O.C. ! W
1 [1955 Ground Surface I>
Ji J
Q - __ 1 I - Q
ZZ Remove and 1995 Ground Surface Z
300— Recompact Area
—300 a
O - ` _ - O
LLRemoval of Sliding - , �� LL
W Surface Material �` �++
W
z 3:1 Temporary Cut -~`��— Z
Z 0— _`�- -- — —-- --_�— _ —0 z
Q Example of Strengthened // Q
w Basal Rupture Surface Basal Rupture Surface J W
Lee
See Text Sec.6.1 W
° a
' A - -
F
l -300— r r ' I I I -300
I I 1 I 1 I I I I I
/ 1 0 300 600 900 1200 1500 1800 2100 2400 2700 3000 3300 3600
DISTANCE IN FEET
/ Cross Section D-D'
ni•r BING YEN & ASSOCIATES, INC. TOPOGRAPHIC CHANGES BETWEEN
DAI
■E■ Geotechnical&Environmental Consultants,Established 1979— 1955 AND 1995 SHOWING THE PROPOSED
P.O.C. AND EXAMPLE OF P.B. CLAY
` A PROJECT NAME: PORTUGUESE BEND LANDSLIDE STRENGTH ENHANCEMENT
Key Map ° PROJECT NO: G-940989 DATE: MARCH 1997 FIGURE 2.9