2000-6492 GC- T Y O F E N C I N I T A
El 'LEERING SERVICES DEPARTME
505 S. VULCAN AVE.
ENCINITAS, CA 92024
GRADING PERMIT
PARCEL NO. : 256- 051 -0700
JOB SITE ADDRESS: 676 -678 NEPTUNE AVE.
APPLICANT NAME LAMPL (JACK W. III)
MAILING ADDRESS: 998 WOODGROVE DR.
CITY: CARDIFF STATE: CA ZIP
CONTRACTOR :
LICENSE NO.:
ENGINEER
PERMIT ISSUE
PERMIT EXP.
INSPECTOR: M
SOIL ENGINEERING CONSTRUCTION INC.
268082
SOIL ENGINEERING CONSTRUCTION INC.
DATE: 6/16/00
DATE: 6/16/01 PERMIT ISSUED BY
IKE VALLES
--- -- - - - - -- PERMIT FEES 6 DEPOSITS
PERMIT NO.: 6492GI
PLAN NO.: 6492 -G
PHONE NO.: 760- 942 -0928
92007-
PHONE NO.: 760- 633 -3470
LICENSE TYPE: A
760 - 633 -3470
1. PLAN CHECK FEE .00 4. INSPECTION DEPOSIT: 1,O0C.00
2. INSPECTION FEE .00 5. SECURITY DEPOSIT .00
3. PLAN CHECK DEPOSIT: .00
-------- -------- --- -- - - -- DESCRIPTION OF WORK -------------------------------
REPAIR SOUTHERLY UPPER WALL BY REMOVING /REPLACING LOWER TIEBPCKS/WALEP„
INSTALLING NEW UPPER TIEBACKS /WALER, REINFORCING MOST SOUTHERLY VERTICAL
COLUMNS WITH CHANNEL STIFFENERS, ALL PER 95 -106 MUP /CDP /EIA, ALL PER
COASTAL PERMIT A- 6- ENC -99 -115. AS- BUILTS REQUIRED PRIOR TO FINAL. NO
ACCESS TO PUBLIC BEACH ALLOWED. OTHER WALLS BY SEPARATE PERMIT.
- -- INSPECTION ---------- - - - - -- DATE -- - - - - -- INSPECTOR'S SIGNATURE - - --
INITIAL INSPECTION
COMPACTION REPORT RECEIVED
ENGINEER CERT. RECEIVED
ROUGH GRADING INSPECTION
FINAL INSPECTION
1 HEREBY ACKNOWLEDGE THAT I HAVE READ THE APPLICATION AND STATE THAT THE
INFORMATION IS CORRECT AND AGREE TO COMPLY WITH ALL CITY ORDINANCES AND STATE
LAWS REGULATING EXCAVATING AND GRADING, AND THE PROVISIONS AND CONDITIONS OF
ANY PERMIT ISSUED PURSUANT TO THIS APPLICATION.
0311M
PRINT NAME
CIRCLE ONE: 1. OWNER 2. AGENT 3
luboo
]w- �3y3`f7o
TELE ONE NUMBBEP.
OTHER_ .
Oct-26 -00 05:36pa %row-PETERSON d PRICE. APC
618- 238 -5813 T -087 P 02/06 F-05
STATE DY CALiipRm: TIE RMXTR EY A LwC GRAY DAVIS. C<rA.+.
CALIFORNIA COASTAL COMMISSION
SANDIEODAREA N �•
1511 YCn D1WP tAN DN &SOM 10 FNOVIO sm EGo. G ntO 2
(EIG) 1 -MU 9 2W to October 23.2000
ication No. 6-00-1
Page 1 of--5_
NOTICE OF INTENT TO ISSUE PERMIT
On October 10. 200Q, the California Coastal Commission approved the application of
Jack Lamp] , subject to the attached standard and special conditions, for the development
described below:
Description: Repairs to an existing unpermitted approximately 36 foot -high, 67 foot -
long debarked seawall involving installation of ten additional , 40 foot -
long tiebacks, placement of concrete gradebeams at new tieback
locations, removal of unpermitted stairway, concrete landing and steps
from face of seawall and coloring of a portion of the seawall.
Site: On public beach fronting 676 -678 Neptune Avenue, Encinitas, San Diego
County. APN(s) 256 - 051-07
The permit will be held in the San Diego District Office of the Commission, pending
fulfillment of Special Conditions 1.2.4. 6. 7 When these conditions have been
satisfied, the permit will be issued.
DEBORAH N. LEE
DEPUTY DIRECTOR
BY
��4
Oct 7-25 -00 10 :Seam
From - PETERSON i PRICE. APC 610 - 230 -E873
. .t.TERSON & PRICE
A P R O F E S S I O N A L C O R P O It A T 1 0 N
FDWA R F WHrM -ER
MARSHALA. SCARR
t:nion Bank of California Building
MATTHEW A. PETERSON
IwR" N. Wr1R.NANE
530 °B° Street, Suite 1700
CHFUTMPHER J. CO:NNO_LY
San Diego, California 92101 -4454
KELLY A. GRALEWSKI
Telephone (619) 234 -0361
nF NMI
Fax (619) 2344786
PAUL A. PETERSON
October 25, 2000
Mr. Gary Cannon
Coastal Program Analyst
California Coastal Commission
7575 Metropolitan Dr., Ste. 103
San Diego, CA 92108 -4402
Re: CDP No. 6 -00 -102
Dear Gary:
T -060 P 02/02 F -460
Carlsbad Offir
703 Palomar Airport Road
Suite 200
Carlsad, California 920094042
Telephone (760) 929 -1920
Fax (760) 929 -2206
File No.
5654.002
Via fax & U.S. mail
Attached please find a Xerox copy of the check and receipt from SANDAG for the
payment of the Sand Mitigation Fee in the amount of $5500. It is our understanding that
you are going to mail to us the Notice of Intent to Issue Permit today. We appreciate
your expedited review and approval of all remaining permit conditions. Our client would
like to start construction by no later than November 2, 2000.
Sincerely,
Peterson & Price
/Professional Corporation
Matthew A. Peterson
cc: John W. Niven, P.E., Soil Engineering Construction Inc.
Jack W. Lamp[, III
(Both with cover letter on:y)
Oct -25 -00 05 :360M ;rcm- PETERSON i PP,ICE. APC 618- 238 —'.873 T -097 P 03/06 F -465
NOTICE OF INTENT T. SUE PERMIT NO. 6-00 10?
Page 2 of 5
STANDARD CONDITIONS:
1. Notice of Receipt and Acknowledgment. The permit is not valid and development
shall not commence until a copy of the permit, signed by the permittee or authorized
agent, acknowledging receipt of the permit and acceptance of the terms and
conditions, is returned to the Commission office.
2. Expiration. If development has not commenced, the permit will expire two years from
the date on which the Commission voted on the application. Development shall be
pursued in a diligent manner and completed in a reasonable period of time.
Application for extension of the permit must be made prior to the expiration date.
3. Intemretation. Any questions of intent or interpretation of any condition will be
resolved by the Executive Director or the Commission.
4. Assignment. The permit may be assigned to any qualified person, provided assignee
files with the Commission an affidavit accepting all terms and conditions of the
permit.
5. Terms and Conditions Run with e Land. These terms and conditions shall be
perpetual, and it is the intention of the Commission and the permittee to bind all future
owners and possessors of the subject property to the terms and conditions.
SPECIAL CONDITIONS:
The permit is subject to the following conditions:
1. Mitigation for Impacts to Sand Supply. PRIOR TO ISSUANCE OF THE
COASTAL DEVELOPMENT PERMIT, the applicants shall provide evidence, in a form
and content acceptable to the Executive Director, that a total fee of $5,520.86 has been
deposited in an interest bearing account designated by the Executive Director, in -lieu of
providing sand to replace the sand and beach area that would be lost due to impacts
resulting from the extend life of the existing protective structure. The methodology used
to determine the appropriate mitigation fee for the subject site(s) is that described in the
staff report dated 9/26/00 prepared for Coastal Development Permit 116-00 -102. All
interest earned shall be payable to the account for the purposes stated below.
The purpose of the account shall be to establish a beach sand replenishment fund to aid
SAINDAG, or a Commission - approved alternate entity, in the restoration of the beaches
within San Diego County. The funds shall solely be used to implement projects which
provide sand to the region's beaches, not to fund operations, maintenance or planning
Oct -25 -00 05:37am prom- PETERSON i PRICE. APC
NOTICE OF INTENT T, SUE PERMIT NO.
Page 3 of 5
618- 239 -5673 T- 097 5 04/06 f -465
studies. The funds shall be released only upon approval of an appropriate project by the
Executive Director of the Coastal Commission. The funds shall be released as provided
for in a MOA between SANDAG, or a Commission- approved alternate entity, and the
Commission, setting forth terms and conditions to assure that the in -lieu fee will be
expended in the manner intended by the Commission. In the event the MOA is
terminated, the Commission can appoint an alternative entity to administer the fund.
2. Monitoring Program. PRIOR TO ISSUANCE OF THE COASTAL
DEVELOPMENT PERMIT, the applicant shall submit to the Executive Director for
review and written approval, a plan prepared by a licensed engineer for a seawall
monitoring program which includes the following:
a. An evaluation of the condition and performance of the seawall and drainage
system, addressing whether any significant weathering or damage has occurred
that would adversely impact the future performance of the seawall or drains.
b. Within 120 days of completion of the repairs authorized by the subject permit,
the applicant shall submit a report to the Executive Director of the Commission
of the evaluation described in Subsection a. above.
c. The applicant shall conduct the evaluation described in Subsection a. above
annually in April of each year for three years beginning with April 2001 and for
submittal of a report to the Executive Director of the Coastal Commission on
May 1 of each year for three years beginning May 1, 2001. Each report shall be
prepared by a licensed engineer and contain recommendations, if any, for
necessary changes or modifications to the seawall.
The permittee shall undertake monitoring in accordance with the approved plan. Any
proposed changes to the approved plan shall be reported to the Executive Director. No
changes to the plan shall occur without a Coastal Commission approved amendment to
this coastal development permit unless the Executive Director determines that no
amendment is required.
3. Future an ris Removal. Within 10 days of completion of
construction of repairs to ttie protective device and within 10 days of completion of the
removal of the stairway and stairway landing, the permittee shall remove all debris
deposited on the beach or in the water as a result of the subject construction activities.
The permittee shall maintain the permitted seawall in its approved state except to the
extent necessary to comply with the requirements set forth below. Any change in the
design of the seawall or future additions/reiaforcement of the seawall beyond minor
regrouting or other exempt maintenance, as defined by Section 13252 of the California
Code of Regulations, will require a coastal development permit. However, in all cases
after inspection, if it is apparent that repair and maintenance is necessary, the permittee
shall contact the Commission office to determine whether permits are necessary.
Oct-25 -00 05: 3713m From - PETERSON C PRICE, APC 5I9- 230 -973 T -037 P 05/05 F -485
NOTICE OF INTENT Tt- SUE PERMIT NO. 6'� 1�
page 4 of _J_
4. Staging Areas /Access 'orridQrs/Timing Of Construction. PRIOR TO THE
ISSUANCE OF THE COASTAL DEVELOPMENT PERMIT, the applicant shall submit
to the Executive Director for review and written approval, final plans indicating the
location of access corridors to the construction site and staging areas. The final plans
shall indicate that.
a. No staging of equipment or materials shall occur on sandy beach or public
parking areas. The permittee shall not store any construction materials or waste
where it will be or could potentially be subject to wave erosion and dispersion. In
addition, no machinery shall be placed, stored or otherwise located in the
- — intertidal zone at any time.
b. Access corridors shall be located in a manner that has the least impact on public
access to and along the shoreline.
c. No work shall occur on the beach on weekends and holidays during the summer
months (Memorial Day to Labor Day) of any year.
d. The applicant shall submit evidence that the approved plans/notes have been
incorporated into construction bid documents. The staging site shall be removed
and/or restored immediately following completion of the development.
The permittee shall undertake the development in accordance with the approved plans.
Any proposed changes to the approved plans shall be reported to the Executive Director.
No changes to the plans shall occur without a Coastal Commission approved amendment
to this coastal development permit unless the Executive Director determines that no
amendment is required.
S. Other Permits. PRIOR TO COMMENCEMENT OF CONSTRUCTION, the
applicant shall submit copies of all other required local, state or federal discretionary
permits for the development herein approved. Any mitigation measures or other changes
to the project required through said permits shall be reported to the Executive Director
and shall become part of the project. Such modifications, if any, may require an
amendment to this permit or a separate coastal development permit.
6. Final Plans. PRIOR TO THE ISSUANCE OF THE COASTAL DEVELOPMENT
PERMIT, the applicant shall submit to the Executive Director for review and written
approval, final repair plans, that have been stamped and approved by the City of
Encinitas. Said plans shall be in substantial conformance with the submitted building
plans dated 12/11 /00 and received by the Commission on 9/21100 and shall include the
following:
Oct -25 -00 05:38Pm From- PETERSON d PRICE. APC 619 - 239 -5873 T -09T ° 06/06 F -485
NOTICE OF INTENT TL SUE PERMIT NO. 6-0U 1(12
Page 5 of 5
a_ Sufficient detail regarding the technology or other indication of the materials
and color scheme (including provision of a color board) to be utilized in
covering the existing 12 ft. high concrete wall that is attached to the top of
the southern half of the seawall to assure the color closely matches the
adjacent natural bluffs.
The permittee shall undertake the development in accordance with the approved plans.
Any proposed changes to the approved plans shall he reported to the Executive Director.
No changes to the plans shall occur without a Coastal Commission approved amendment
to this coastal development permit unless the Executive Director determines that no
amendment is required.
7. Assumption of Ri k. PRIOR TO ISSUANCE Of THE COASTAL
DEVELOPMENT PERMIT, the applicant shall execute and record a deed restriction, in a
form and content acceptable to the Executive Director, which shall provide: (a) that the
applicant understands that the site may be subject to extraordinary hazard from storm
waves, erosion and bluff collapse, and the applicant assumes the.liability from such
hazards; and (b) the applicant unconditionally waives any claim of liability on the part of
the Commission or its successors in interest for damage from such hazards and agrees to
indemnify and hold harmless the Commission, its officers, agents, and employees relative
to the Commission's approval of the project for any damage due to natural hazards. The
document shall run with the land, binding all successors and assigns, and shall be recorded
free of prior liens that the Executive Director determines may affect the enforceability of
the restriction. This deed restriction shall not be removed or changed without a Coastal
Commission - approved amendment to this coastal development permit unless the Executive
Director determines that no amendment is required.
(o-oo -ioza)
S;A7E OF C1[JPoRNIA- -'S1iE RESOURCES AGENC'f GRAYDAVIS. G vemur
CALIFORNIA COASTAL COMMISSION
SAN r1EW AREA
11 i 1 CAMINO DEL RIO NORM. S= 100
SAN OIECA, U 9110&1725
(6191 511 -8076
Date May 15, 2000
Application No. A- 6- ENC -99 -115
Page 1 of 2
NOTICE OF INTENT TO ISSUE PERMIT
On February 15. 2000 , the California Coastal Commission approved the application of
Jack Lamal , subject to the attached standard and special conditions, for the
deve!opment described below:
PROJECT DESCRIPTION: Repair and improvements to an existing approximately 10
foot -high, 18 foot -long mid bluff retaining wall and two approximately 35 foot -
high, 50 foot -long (total) upper bluff retaining walls.
PROJECT LOCATION: 676 -678 Neptune Avenue, Encinitas, San Diego County.
APN 256- 051 -07
The permit will be held in the San Diego District Office of the Commission, pending
fulfillment of Special Conditions 1 When these conditions have been satisfied,
the permit will be issued.
DEBORAH LEE
DEPUTY DIRECTOR
BY
' NOTICE OF INTENT SSUE PERMIT NO. A- 6- ENC -99 -1
Page 2 of 2
STANDARD CONDITIONS:
Notice of Receipt and Acknowledgment. The permit is not valid and development
shall not commence until a copy of the permit, signed by the permittee or authorized
agent, acknowledging receipt of the permit and acceptance of the terms and
conditions, is returned to the Commission office.
2. Expiration. If development has not commenced, the permit will expire two years from
the date on which the Commission voted on the application. Development shall be
pursued in a diligent manner and completed in a reasonable period of time.
Application for extension of the permit must be made prior to the expiration date.
3. Compliance. All development must occur in strict compliance with the proposal as set
forth below. Any deviation from the approved plans must be reviewed and approved
by the staff and may require Commission approval.
4. Interpretation. Any questions of intent or interpretation of any condition will be
resolved by the Executive Director or the Commission.
5. Inspections. The Commission staff shall be allowed to inspect the site and the
development during construction, subject to 24 -hour advance notice.
6. Assignment. The permit may be assigned to any qualified person, provided assignee
files with the Commission an affidavit accepting all terms and conditions of the
permit.
Terms and Conditions Run with the Land. These terms and conditions shall be
perpetual, and it is the intention of the Commission and the permittee to bind all future
owners and possessors of the subject property to the terms and conditions.
SPECIAL CONDITIONS:
The permit is subject to the following condition:
1. Final Plans. PRIOR TO THE ISSUANCE OF THE COASTAL
DEVELOPMENT PERMIT, the applicant shall submit to the Executive Director for
review and written approval, final repair and maintenance plans, that have been stamped
and approved by the City of Encinitas. Said plans shall be in substantial conformance
with the submitted building plans dated 12/11/98 and received by the Commission on
9/10/99.
The permittee shall undertake the development in accordance with the approved plans.
Any proposed changes to the approved plans shall be reported to the Executive Director.
No changes to the plans shall occur without a Coastal Commission approved amendment
to this coastal development permit unless the Executive Director determines that no
amendment is required.
(A- 6- ENC -99 -1150
SOIL
cnclnec4mc
e^ncr�11 1-1^n
November 9, 2000 R /1D
Department of Engineering
City of Encinitas p n20W 505 S. Vulcan Avenue Encinitas, California NOV RE: Lampl Residence Seawall Repairs 678 Neptune Avenue _i OF EN IN TAS
Concrete Mix Design Submittal
Attention: Mr. Greg Shields, P.E.
Attached, please find concrete mix designs (68P & 375PAE) for the seawall and for the
tiebacks (9625 FLOW) or as per the notes on the drawings, which are submitted for your
review and approval. All mix designs meet or exceed the minimum concrete design
specifications for this project.
If you should have any questions or require additional information, please contact us at
(760) 633 -3470.
Ve truly your
` r
hn W. Niven, P.E.
Soil Engineering Construction Inc.
C: Engineering Inspection
927 Arguello Srreer, Redwood Ciry, California 94063 -1310 (650) 367 -9595 • FAX (650) 367 -8139
MIX ID : 68P C J
Superior Ready Mix
IS08 W. Mission Rd
Escondido, CA 92029
(760)74S-0556
CONCRETE MIX DESIGN
4000 PSI 09/27/00
CONTRACTOR : SOIL ENGINEERING
PROJECT : L414FL RESIDENCE
SOURCE OF CONCRETE SUPERIOR READY MIX CONCRETE, L.P.
CONSTRUCTION TYPE VARIOUS
PLACEMENT : 3/8" PUMP
WEIGHTS PER CUBIC YARD (SATURATED,
ASTM -C150 TYPE II /V CEMENT (MITSUSISHI), LB
ASTM -C33 WASHED CONC. SAND (SUPERIOR), LB
ASTM -C33 #8 ROCK (SUPERIOR), LB
WATER, LB (GAL-US)
TOTAL AIR, %
MASTER BUILDERS POZZ 322N, OZ -US
WATER /CEMENT RATIO, LBS /LB
SLUMP, IN
CONCRETE UNIT WEIGHT, PCF
REPARED BY :
UPERI OR REAOX_O�M CONCRETE, L.P.
SURFACE -ORY)
YIELD,
CU FT
752
3.83
17A7
10.65
951
5.82
385 ( 46.1)
6.17
2.0 +/- 1.0
0.54
zzazsaa
TOTAL
27.00
30.08
0.51
6.00
142.1
^W
1/
R
K
A
B
I
L
T
Y
MIX #68P
MIX ANALYSIS
MTX VOLUME, CU FT 27.00
COARSENESS (Q / (C + I)) 3,8
WCRKASILITY 54.0
w - ADJUST 59.0
PERCENT MORTAR 72.0
TOTAL FINENESS MODULUS 3_qb
45 i--------- i---------i---- -- --- i---------
, ..
40
I I 1
I I I I I I
1 1 1
35 1 1 1 I .
I 1
30 --- - - - - - -, ..... .... ---------
I
I
i
x - TOTAL MIX ;
1 ; o - AGGREGATES
1 _ BOTH
1
* �
<O ; - ...- ------
i---- -- --- i--------- i---- - - - - -' 1
100 80 6C 40 20 O
C O A R 5 E N E S S [ O/( C + I)
MATERIALS CHARACTERISTICS
STONE SAND
DENSITY, SP G 2.62 2.63
% PASSING 3/8 SIEVE 95.0 100.0
% PASSING # 8 SIEVE 1.0 83,0
FINENESS MODULUS 5.84 2,93
PERCENT OF AGGREGATE 35.3 64.7
NO SEVEP.E EXPOSURE
P
E
R
C
E
N
T
P
A
5
S
N
G
MIX #68P
FULL GRADATION ANALYSIS
SIEVE STONE SAND PASTE TOTAL_ AGGR
- - - - --- - - - - - -- - ---- -- - - - - - --
1-2/2 100.0 100.0
I lO0 -O 100.0
3/4 100.0 100.0
1/2 100.0 100.0 100.0
3/8 95.0 100.0 98.9 98.2
K 4 20.0 98.0 82.0 70.4
# 8 1.0 83.0 72.0 54.0
16 - 63.0 63.'3 40.7
# 30 - 39.0 54.4 25.2
x 50 - 18.0 46.1 11.6
4 100 - 6.0 41.4 3.9
ii 200 - 2.9 100.0 40.2 1.9
x 325 - - 94.6 36.9 -
LigLid - - 63.7 24.9 -^
GRADATION CHART
lOC x___* *___*____ i_____ i------ i__ ___i___i------ i-----
i- .__...__.
• � r i r . t r r r r r
r .
9C-- ' -' -- I r -- -- -'----- ' - - - --' - ------ ' - - - --'
70 I
i
i I 1 1
i -r -i i- .-- -0- X- - - - -r- I r r I r I
r
I I r I r r r x . - I r r r
i
0
50
40 I I I I r I I x I r r
I r r- -- . -r - - -I I- - - - -0- I - - -r X`- - - -X -- i i
30 I i r r I I I i i
1 x
r i r
i I I r r r
r r r I r I r r O r I i i x
20 '---' '---'-'---'-__--'-----'- ----- ---'-------
'-----'---�---i
i i -r i t i r i I i r
O
0 i---'- '---'-'--- '-----'- ' r r
1 1 3 1 3 # # # # R 1 2 3
SIEVE / // 4 8 1 3 5 0 O 2 i
5 4 2 8 6 0 0 0 0 ° q
x - ALL COMPONENTS o - AGGREGATES * - BOTH
MIX IO : 375PAE [ ]
Superior Ready Mix
1508 W. Mission Rd
Escondido, CA 92029
(760)745-0556
CONCRETE MIX DESIGN
4000 PSI
CONTRACTOR SOIL ENGINEERING
PROJECT . L.9t`t l RESIDENCE
SOURCE OF CONCRETE SUPERIOR READY MIX CONCRETE, L.P.
CONSTRUCTION TYPE : VARIOUS
PLACEMENT 40 PUMP /PLACE
WEIGHTS PER CUBIC YARD (SATURATED
ASTP' -C1SO TYPE II /V CEMENT (MITSUBISHI), LB
ASTM. -C33 WASHED CONC. SAND (SUPERIOR), LB
ASTM -C33 057 ROCK (SUPERIOR), LB
ASTM -C33 08 ROCK (SUPERIOR), LB
WATER, LB (GAL -US)
TOTAL AIR, %
MASTER BUILDERS POZZ 322N, OZ -US
MASTER BUILDERS MICRO AIR, OZ -US
WATER /CEMENT RATIO, LBS /LB
SLUMP. IN
CONCRETE UNIT WEIGHT, PCF
DREPARED SY :
SUPERIOR
CONCRETE, L.P.
09/27/00
SURFACE -DRY)
YIELD, CU FT
705
3.59
1320
8.04
1286
7.87
321
1.97
295 ( 35.3)
4.73
3.0 +/- 1.0
0.81
777 TOTAL
28.20
1.8
0.42
4.00
145.5
W
O
R
K
A
B
I
L
I
T
Y
MIX #375PAE
MIX ANALYSIS
MIX VOLUME. CU FT 27.00
COARSENESS (0 / (O + I)) 70.9
WORKABILITY 37.5
N - ADJUST 41.2
PERCENT MORTAR 58.6
TOTAL FINENESS MODULUS S_10
45 i--------- - --- -----'-- --------- ---------
x
40 --- -- - - -- --------- i--------- i--------- --------- ,
35 --------- '--------- '---------
'_ -'
r , ,
30 -- -- - - - - -, --------- ---------
25 - ...... -• - - --' '--- ----- -' ,
,
X - TOTAL MIX
o - AGGREGATES
* - BOTH '
100 80 60 40 20 O
C O A R S E N E S S [ Q/( 0 + I) }
MATERIALS CHARACTERISTICS
STONE 1 S70NE 2 SAND
- ---- -- --- ---- ---
DENSITY, SP G 2.62 2.62 2.63
PASSING 3/8 SIEVE 1.0 93.0 100.0
% PASSING # 8 SIEVE - 1.0 83.0
FINENESS MODULUS 7.14 5.84 2.93
PERCENT OF AGGRESATE 44.0 11.0 45.0
NO SEVERE EXPOSURE
MIX #37SPAE
FULL GRAOATION ANALYSIS
SIEVE
---
STONE 1 STONE 2 SAND PASTE
- - - --
TOTAL
-- ---
AGGR
1-1/2
"
- - - -- - - - - - --
100.0
- - - - - --
100.0
1 "
100.0
100.0
100.0
3/4
84.0
95.3
93.0
1/2
25.0 100.0
78.2
67.0
3/8
1.0 93.0 100.0
70.7
55.7
# 4
1.0 22.0 98.0
64.9
47.0
# 6
- 1.0 83.0
58.6
37.5
# 16
- - 63.0
52.6
28.4
# 30
- - 39.0
45.4
17.6
# SO
- - 18.0
39.2
8.1
F 100
- - 6.0
35.6
2.7
# 200
- - 2.9 100.0
34.7
1.3
# 32°
- - - 94.1
31.8
-
LigUiC
- - - 60.7
20.5
-
GRADATION CHART
100
--- --- �-----
_ - -'
---
90
- --
-' -- -' '-- -'--- -- '----- ' - - - - -'
--- ---
i
P
r
R
C70
i___ i_
i____ Y--^ i----- i-____ i _----i---i_---
-_'_____'___'___'
E
1
r
,
� O I X
r
N
60
- - - --
- --
T
50
- - -'-
--- '----- '---- _'_____'___'-
--- - -'
_'
_ -'
F'
A40
'---'-'--
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SIEVE
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ALL COMPONENTS v •• AGGREGATES
-
BOTH
MIX ID : 9625 FLOW ( )
Superior Reedy Mix
1508 W. Mission Rd
Escondido, CA 92029
(760)745-0556
CONCRETE MIX DESIGN
4000 PSI 09/27/00
CONTRAC7CR SOIL ENGINEERING
PROJECT ANI;;_
'RESIDENCE
SOURCE OF CONCRETE SUPERIOR READY MIX CONCRETE, L.P
CONSTRUCTION TYPE : VARIOUS
PLACEMENT : 3/8" PUMP / TRUCK PLACE
WEIGHTS PER CUBIC YARD (SATURATED,
ASTM -CI50 TYPE II /V CEMENT (MITSUBISHI), LB
MASTER BUILDERS FLOW CABLE, LB
ASTM -C33 WASHED CONC. SAND (SUPERIOR), L8
ASTM -C33 #8 ROCK (SUPERIOR), LB
WATER, LB (GAL-US)
TOTAL AIR, %
WATER /CEMENT RATIO, LBS /LB
SLUMP, IN
CONCRETE UNIT WEIGHT, PCF
PREPARED BY
SUPERIOR READY OTX CONCRETE, L.P.
SURFACE -ORY)
YIELD, CU FT
588 2.99
29 0.20
1920 11.70
1223 7.48
272 ( 32.6) 4.36
1.0 0.27
as�a ee—
TOTAL 27.00
0.44
8.00
149.3
W
0
R
K
A
Q
I
L
I
T
Y
MIX #9625 FLOW
MIX ANALYSIS
NO SEVERE EXPOSURE
MIX VOLUME. CU FT
27.00
COARSENESS (O / (c * I))
4.0
WORKABILITY
51.0
W - ADJUST
52.4
PERCENT MORTAR
65.2
TOTAL FINENESS MODULUS
4.06
45
--------- ' - ' --------- ' ---------
1 1 I 1
I
I
I r I r
I
I
I 1 t I
I
35
------ --- '-- -- - - - --' ---- - - - -'-
.1
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I
I I
r
I
30
'---- -- - --i ---------
---------i
1 I
I
I
25
..... -- '--------- '--------- '---------
---------
'
x -
TOTAL MIX
;
0 -
AGGREGATES
;
-
80TH
2
I I I
I
I
I
100 80 60 40
20
O
C O A R S E N E S S [ O/ (O
* I) ]
MATERIALS CHARACTERISTICS
STONE
SAND
DENSITY, SP G 2.62
2.63
* PASSING 3/6 SIEVE 95.0
100.0
PASSING # 8 SIEVE 1.0
83.0
FINENESS MODULUS 5.84
2.93
PERCENT OF AGGREGATE 39.0
61.0
MINERAL ADMIXTURE 0£NSITV, SP G
2.31
NO SEVERE EXPOSURE
P
E
R
C
E
N
T
P
A
5
S
I
N
G
MIX 09625 FLOW
FULL GRADATION ANALYSIS
SIEVE
-
STONE
SAND
--
PASTE TOTAL
- --^ -
AGGR
-
1-1/2
- - - - - --
- - - - -
100.0
- - - - --
100.0
1
100.0
100.0
3/4
100.0
100.0
1/2
100.0
100.0
100.0
3/8
95.0
100.0
98.6
98.1
0 4
20.0
98.0
77.0
67.6
# 8
1.0
83.0
65.2
51.0
# 16
-
63.0
56.3
38.4
# 30
-
39.0
45.9
23.8
# 50
-
18.0
36.8
11.0
# 100
-
6.0
31.6
3.7
# 200
-
2.9
100.0 30.2
1.8
# 325
-
-
94.1 27.3
-
Liquid
-
-
59.2 17.1
-
GRADATION
CHART
100
�
------'
r ----- '- - -'---
r r
r
90
i-- -� -'
r r r
,---
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- --'
80
r
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r ,'•- I
r
I
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70
- ' - - --
-' °- '-'--- '------
'----- '-- -' - - -'
x r r
r i r i
50
r - -'t
- - - -0-
I---- -,-- -r ,
i t
r--- r-
40
----
- -' - -- --1---i r
r
r i I
r
0 1
1 I x I
20
- - -'-'
__
-- -'- - --
- -' - -' - - -'
r
1 1
r r
I
1 1 r
1 1 r
10
-r - - -r
O-
,-
i
O
0
' - - - ! - I - �-
r , r
, -
I I
1
1 _ 3
1 3 0
#
# # #
1 2 3 L
5IEVE
/
!/ 4
8
1 3 5
0 0 2 i
5 4
2 A
6 0 O
D 0 5 q
x - ALL
COMPONENTS
o
- AGGREGATES
xc - BOTH
SOIL
Enclniatnc
consciucclon..,
April 19, 1999
Ms. Diane Langager - Planning Department
City of Encinitas
505 S. Vulcan Avenue
Encinitas, CA 92024
Subject: Response to Third Party Review Dated February 25, 1999
Lampl Residence, 678 Neptune Avenue
Encinitas, California
Dear Ms. Langager
Soil Engineering Construction, Inc. (SEC) has prepared the following letter to address comments
raised in the third party review prepared by Engineering Geology Consultants dated February 25,
1999. In order to satisfy the requirements of the City of Encinitas Municipal Code, we offer the
following additional responses:
SEC has reviewed Section 30.34.020 B9. Based on our understanding and interpretation of the
section relative to the Lampl application and geotechnical documentation, this project meets the
criteria as a seawall necessary to protect the existing principal structure.
The existing coastal bluff protective structures were developed by previous owners of the property
prior to the adoption and implementation of Section 30.34.020 B.9. The current owner (Lampl) is
working with the City of Encinitas and the California Coastal Commission to bring the project into
permit conformance.
It is our opinion that if the structures were not already present, the site would be in a state of failure
that would imminently threaten the primary residential structure. It is our opinion that the removal.
or reduction in scope, of any bluff retention structures presently on the project site would immediately
cause failure on the property that would threaten the primary residential structure.
Repair construction proposed as an element of this project will negate the existing potential for
failures of existing bluff protective devices that would place the primary residential structure in
imminent threat of damage and/or failure.
The project, as designed will not have a significant adverse impact on local shoreline sand supply.
The city's Community Development department has already determined that the applicant's inclusion
in this application of plans for a minor remodel/addition on the property are in conformance with the
limitations established in Section 30.34.020 B.9.
027 Arqueilo Srreer Reowcea Ciry California 0e063 -1310 (650' 367 -9595 • FAX (650) 367 -8139
Ms. Diane Langager
City of Encinitas
April 19, 1999
Page
We hope the above information satisfies your requests at this time. If you should need any additional
information, please contact us at (760) 633 -3470.
Sincerely,
SOIL ENGINEERING CONSTRUCTION, Inc.
John W. Niven Kobert Mahony
R.C.E. 57517 G.E. 554,C.E G. 7
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SOIL
consviumon.
February 8, 1999 W
Ms. Diane Langager
Associate Planner
City of Encinitas
505 S. Vulcan Avenue
Encinitas, California 92024
Response to Third Party Review of Geotechnical Information
Lampl Residence 678 Neptune Avenue
Encinitas, California
Dear Ms. Langager:
Soil Engineering Construction, Inc. (SEC) has prepared the following responses to address
issues raised by Mr. Artim in his December 28, 1998 review letter.
In order to satisfy requirements of the City of Encinitas Municipal Code. Sections 30.34.020
C and D, as amended by Ordinance 91 -19 and Resolutions 95 -31 and 95 -32 and to respond to
issues raised by Mr. Artim, we offer the following responses.
1. References reviewed for our work are attached to this correspondence.
2. In general, SEC accepts the findings, as they relate to the work proposed, of the
following geotechnical related information:
a. Accutecb Engineering Systems, Inc., 1995, Residence Located at 678 Neptune
Avenue, Encinitas, CA 92024, dated January 17, 1995.
b. Geosoils, Inc., 1997, Response to City Reviews, 678 Neptune Avenue, Encinitas,
California, dated August 4, 1997.
C. Geosoils. Inc., 1997, Telephone Conversation Summary Regarding Slope
Stability, 678 Neptune, Encinitas, California,dated August 29, 1997.
d. Hart, Michael W., 1995, Residential Property, 678 Neptune Avenue, Encinitas,
CA, Geologic Reconnaissance, dated February 6, 1995.
e. Southern California Soil and Testing, Inc., 1996, Summary of In -Place Density
Tests, upper Seawall Backfill, 678 Neptune Avenue, Encinitas. California, dated
May 29, 1996.
3. We, SEC. certify that the proposed development will have no adverse affect on the
027 Arc ue!Io :rreer Redwood Ciry CoIifornto 94063- 1310 '650) _167 -0595 • SAX 050' •3 6-
Ms. Diane Langager
February 8. 1999
Yage2
stability of the bluff, will not endanger life or property, and that the proposed structure
is expected to be reasonably safe from failure over its expected lifetime. It is also our
professional opinion that the project has been designed so that it will neither be subject
to nor contribute to significant geologic instability throughout the life span of the
project or over its lifetime without having to propose any further shore or bluff
stabilization to protect the structure in the future. Work on preemptive bluff
stabilization devices, constitutes the only site improvements within 25 feet of the bluff
top.
4. It is our opinion that the ongoing structural distress of the upper wall is mainly caused
by the crushing of the vertical members at the lower row of tiebacks. splitting of the
vertical timbers between the middle and upper rows of tiebacks. Our request for an
emergency permit was based on information provided to us bb the owner regarding his
apparent observations. It is our opinion that the upper retaining wall will continue to
experience distress, and potential failure, unless the repair recommendations proposed
by SEC are implemented. Repair of the mid bluff wall will include the replacement of
some of the horizontal lagging members and possibly some additional strengthening of
the bracing members. The repairs to the lower seawall are required because the
existing tieback heads have been affected by corrosion. As proposed, the repair work
will include corrosion protective coverings over all new and existing exposed tieback
anchors.
It is our opinion. that if the repairs are implemented no additional significant repairs
will be necessary over the life span of the project. The life span of the repair work
should be considered the same as similar projects in the area.
5. Existing exposed tiebacks will be protected by cleaning off corrosion, painting with an
epoxy coating and capped with a galvanized tieback cover filled with an epoxy based
grout or a non shrink cement grout. Our contract with the owner provides that this
work will be performed.
6. We have recommended that some limited repairs of the mid bluff wall be performed.
Based on our observations, some of the vertical and horizontal wood timbers are in
Ms. Diane Langager
February 8. 1999
Page 3
need of replacement members and possibly some additional strengthening of the
bracing members.
7. The proposed room addition is addressed in a separate letter report and will be
submitted with this correspondence.
8. Two hand augered borings were advanced into the bluff materials at two locations
below the upper bluff retaining wall (see Boring Location Map, Figure 1). [n boring
B -1, fill materials consisting of light brown to yellow brown silty sand, dry, medium
dense were encountered to a depth of seven (7) feet. Underlying these fill materials
Terrace deposits consisting of orange brown to brown slightly cemented silty sand, dry,
medium dense were encountered. The total depth of this boring was approximately 7.5
feet. Boring B -2 encountered fill materials to its full depth approximately 11.5 feet,
and the materials were similar as that described above for B -1. As noted, the fill
materials encountered were observed to be dry. The observed separation between the
existing backfill and the base of the upper retaining wall could have been caused by
surface water infiltrating the backfill materials causing settlement of the materials.
Two hydro- collapse tests were performed on relatively undisturbed ring samples
obtained from the borings. The tests were performed by Kleinfelder & Associates and
the test results indicated a very low potential for collapse (less than 1 percent). Based
on these test results, it is our opinion that further settlement of the backfill materials
may be on the order of 1 to 2 inches. The repairs proposed to the upper retaining wall.
installation of a new row of tiebacks along the base of the wall with a new concrete
waler, will, in our opinion, provide the wall with the necessary support along its base.
Ms. Diane Langager
February 8, 1999
Page 4
Thank you, in advance, for providing your professional in -house and third -party review and
if you have any questions, please call us at (760) 633 -3470.
Very truly yours,
SOIL ENGINEERING CONSTRUCTION, INC.
Robert D. Mahony, .E., C.E.G.
CJ n W. Niven, P.E.
R pF ES3 /p�y
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REFERENCES
Accutech Engineering Systems, Inc., 1995, Residence Located at 678 Neptune Avenue, Encinitas.
CA 92024, dated January 17, 1995.
A.D. Hinshaw Associates, 1997, The Schnoebelen Retaining & Seawall Project, Extended Initial
Study, Case No. 95 -106 MUP/EIA, dated October 2, 1997.
Atom, Ernest R., 1995, Project Number 95-42, Third Party Review of Geotechnical Information, 678
Neptune Avenue, Encinitas, California, dated May 18, 1995.
Artim, Ernest R., 1995, Project Number 9542a, Supplemental Third Party Review of Geotechnical
Response by Skelly Engineering, 678 Neptune Avenue, Encinitas, California, dated June 23,
1995.
Artim, Ernest R, 1997, Project Number 95 -42b, Supplemental Third Party Review of Geotechnical
Information, 678 Neptune Avenue, Encinitas, California, Case Number: 95 -106 MUP/EIA,
dated September 4, 1997.
Benton Consulting Group, Inc., 1985, Calculations, Seawall for Mr. & Mrs. Swift, 678 Neptune
Ave., Encinitas, CA, dated April 26, 1985.
City of Encinitas, Municipal code, Sections 30.34.020C & D.
City of Encinitas, 1985 -86, 85 -116 MUP, Permit Application, Swift Residence.
City of Encinitas, 1995, Use Permit Application, Application Number 95 -106 \"/EIA, dated May
5, 1995.
Converse Consultants, Inc., 1995, Proposed Sea Wall 678 Neptune Avenue, Encinitas, San Diego
County, California, dated April 19, 1985.
Earth Systems Design Group, 1993, Cross Sections, Lower Upper Wall, Schnoebelens Residence,
678 Neptune Avenue, Encinitas, CA, 24 "x36" Plan, Sheet 2, dated As -Built January 4, 1993.
Earth Systems Design Group, 1993, Plans for the Repair of Existing Shoring Systems, Upper Wall
(Repair), Schnoebelens Residence, 678 Neptune Avenue, Encinitas, CA., 24 "x36" Plan, Sheet
1, dated As -Built January 4, 1993.
' Engineering Geology Consultants, 1997, Project No. 95 -42b, Supplemental Third Party Review of
Geotechnical Information, 678 Neptune Avenue, Encinitas, California, CASE NUMBER: 95-
106 MUP/EIA, dated September 4, 1997.
First Phase Engineering, Not Dated, Res, Seawall, 678 Neptune Avenue, Encinitas, California,
24 "x36" Plan, Drawing Sheet No.].
Geosoils. Inc., 1997, Response to City Reviews, 678 Neptune Avenue, Encinitas, California, dated
August 4, 1997.
Geosoils, Inc., 1997, Telephone Conversation Summary Regarding Slope Stability, 678 Neptune,
Encinitas, Califomia,dated August 29, 1997.
Hart, Michael W., 1995, Residential Property, 678 Neptune Avenue. Encinitas, CA, Geologic
Reconnaissance, dated February 6, 1995.
Landscape Solutions, 1995, Landscape Planting Slope Section, Schnoebelen Residence, 678 Neptune
Avenue, Encinitas, California, dated May 23, 1995.
Leighton and Associates, Inc., 1986, Geotechnical Assessment, Proposed Single - Family Residence
at 660 Neptune Avenue, Leucadia, San Diego County, California, Project No. 4861180 -01,
dated February 10, 1986.
Leighton and Associates, Inc., 1987, Estimated Bluff Retreat and Foundation Setback, Proposed
Single - Family Residence at 660 Neptune Avenue, Leucadia, California, dated June 17, 1987.
Leighton and.Associates, Inc., 1989, Geotechnical Update, Existing Duplex at 656 Neptune Avenue,
Leucadia, California, dated June 21, 1989.
LeRoy Crandall and Associates, 1971, Opinion re Soil Conditions, Proposed Residence, Between 660
and 680 Neptune Avenue, Lot 19, PTN BLKS E and F, South Coast Park No.3, Leucadia,
California, dated February 4, 1971.
Naval Facilities Engineering Command 1986, NAVFAC DM -7.01 Soil Mechanics, dated September,
1986.
Naval Facilities Engineering Command, 1986, NAVFAC DM -7.02 Foundations and Earth Structures,
dated September, 1986.
Naval Facilities Engineering Command, 1988, MIL -HDBK- 1025/4 Seawalls, Bulkheads , and
Quaywalls, dated September 30, 1988.
Ninyo & Moore, 1989, Limited Geotechnical Evaluation for Feasibility of Purchase, 678 Neptune,
Encinitas, California, dated April 12, 1989.
Novak , Meulmester & Associates, 1995, Slope Stabilization, 678 Neptune Ave. - Encinitas, CA,
NMA Job No. 95- 025.01, dated June 14, 1995.
Novak - Meulmester & Associates, 1995, Schnoebelen Residence, Structural Calculations, Sheets I
Through 11, Job No. 95 -025, dated April, 1995.
San Diego County Assessor's Map, BK 256, PG 05, Scale V = 100'
Skelly Engineering, 1995, Slope Stabilization Walls, Schnoebelen Residence, 678 Neptune
Avenue, Encinitas, California, 24 "06" Plan, Drawing Sheet No.s Sl, S2, S3, dated April
6, 1995.
Skelly Engineering, 1995, Schnoebelen MUP 95 -106, Reply to Third Party Geotechnical
Review, dated June 14, 1995.
Soil Engineering Construction, Inc., 1998, Limited Geotechnical Assessment, 656, 658, & 660
Neptune Avenue, Encinitas California, dated November 2, 1998.
Soil Engineering Construction, Inc., 1998, Repair of Existing Upper Bluff Retaining Wall, 656, 658,
& 660 Neptune Avenue, Drawing Sheet No.s 1 & 2, dated December 15, 1997, revised
September 21, 1998.
Southern California Soil and Testing, Incorporated, 1995, Report of Geotechnical Investigation,
Proposed Ocean Bluff Stabilization, 724 Neptune Avenue, Encinitas, California, dated July
3. 1995.
Southern California Soil and Testing, Inc., 1996, Summary of In -Place Density Tests, upper Seawall
Backfill, 678 Neptune Avenue, Encinitas, California, dated May 29, 1996.
Thompson. Brian L., 1998, Schnoebelen Residence, 687 (sic) Neptune Avenue, Encinitas, California.
U.S. Army Corps of Engineers, Oceanside, Ocean Beach, Imperial Beach, and Coronado, San Diego
County, Calif., Beach Erosion Control Study.
Woodward -Clyde Consultants, 1989, Geologic Investigation, 652 Neptune, Leucadia, California,
dated August 21, 1989.
SOIL
EnclnEE3mc
consuiucclon,,
December 14, 1998
TO: Ms. Diane Langager R/0
Community Development
City of Encinitas
Mr. Hans Jensen
Engineering Department
City of Encinitas
FROM: Mr. Bob Mahony & John Niven
Soil Engineering Construction, Inc.
RE: Limited Geotechnical Assessment Update
678 Neptune Avenue
Encinitas, California
Soil Engineetirtg Construction, Inc. (SEC) has prepared the following limited geotechnical update
letter report regarding the repair of the existing upper and lower bluff walls at the subject properties.
This report updates an earlier report prepared for the subject property prepared by Michael W. Hart
dated February 6, 1995. The following report includes our observations, conclusions, and
recommendations for the repair of portions of the existing upper bluff retaining wall (southern half).
In addition, we have prepared recommendations for maintenance repairs to the existing lower bluff
seawall.
In preparation for our work, we have performed a detailed site reconnaissance, reviewed the report
"Residential Property, 678 Neptune Avenue, Encinitas, CA, GEOLOGIC RECONNAISSANCE ",
prepared by Michael W. Hart, dated February 6, 1995 and have had detailed conversations with the
property owner Mr. Jack Lampl. In addition, we have reviewed documents, reports and maps
contained in the permitting files at the City of Encinitas, California Coastal Commission as well as
information provided to us by Mr. Lampl. The references reviewed are attached to this letter report.
It is our opinion that, within the past 90 days, the distressed condition of the upper retaining wall,
located on the southern half of the property, has accelerated significantly, placing the residential
structure on the subject lot as well as the neighboring property (660 Neptune Avenue) in imminent
threat of failure. Our opinion is based on the recent observations of the distressed portions of the
lower part of the wall, where visible crushing of the vertical columns at the tieback locations and
their resulting relaxation/loss of tensioning (See Figures 1 and 2), severe cracking/splitting of the
two southernmost vertical columns (See Figure 3) and the recent separations of the existing upper
retainine wall, brick decking, and fencing (See Figure 4), and the recent vertical separation
_�_ cue •o rrFO. `.rr. _oa Gry Ccnforna 0,10611-1310 (650) 67 -0595 PAX c50 --
Ms. Diane Langager & Mr. Hans Jensen
Citv of Encinitas
December 14, 1998
Page 2
approximately 3 inches wide between of the existing slope materials and the base of the upper
retaining wall (See Figure 5). It is our opinion that the sudden and unexpected acceleration of the
concerns affecting the site provide visible indication that the primary residential structures at 678
and at 660 Neptune are imminently threatened. Presented herein are our findings, conclusions and
recommendations for the subject properties.
The subject property consists of residential lot adjacent to and west of Neptune Avenue in the City
of Encinitas. Based on information available. it appears that the subject residence is founded on a
caisson grade beam system along its' western exterior wall. The caissons appear to be on the order
of approximately 15 to 18 feet in depth. The lot is bounded on the west by the Pacific Ocean and
on the north and south by other residential lots. Elevations range from sea level on the western site
boundaries to approximately 95 feet (M.S.L.) alone the building pad level. A concrete seawall
constructed at three different times, approximately 37 feet high, is located at the bottom of the bluff
along the western boundary. The wall has an approximately 1.5:1 (horizontal to vertical) backfill
extending upward to an estimated height of about 40 feet above the top of seawall. An upper
retaining wall exists eastward of the referenced slope and mid bluff wall and is approximately 20
feet in height. The upper retaining wall consists of two walls, (northern and southem)which were
constructed at different times. The northern wall was constructed in 1995 after an upper bluff
failure and consists of tied back concrete columns and horizontal wood lagging. The southern half
wall appears to have been constructed in 1989 and consists of tied back wood/timber columns. one
horizontal wood/timber wafer with tiebacks and horizontal wood laeeine. Vegetation on the slope
below the upper retaining wall consists of a moderate growth of landscaping flora.
During our site reconnaissance, we observed the overall conditions of the lower and upper walls.
It appears that the tiebacks for the lower seawall are severely affected by corrosion and are in need
of replacement.
We observed that the upper retaining wall. southern half is structurally distressed. The lower
portions of the vertical columns are crushed at each tieback location, severe cracking/splitting of
the two southernmost vertical columns are visible and the recent separations of the existing upper
retaining wall, brick decking, and fencing indicates some lateral movement of the wall is occurring,
and a recent separation approximately 3 inches wide between the existing slope materials and the
678aN gm
Ms. Diane Langager & Mr. Hans Jensen
City of Encinitas
December 14, 1998
Page 3
base of the upper retaining wall. Our recommendations for the repair of these conditions are
discussed herein.
General Geology and Subsurface Conditions
The subject property is located in the Coastal Plains Physiographic Province of San Diego Countv
and is underlain by Tertiary and Quaternary-age sediments and associated topsoils.
The oldest materials at the site are the sedimentary deposits of the Eocene Torrey Sandstone. These
deposits consist of generally of gray to light brown sandstones. Overlying the Eocene -age sediments
are Quatemary -age terrace deposits which form the major portion of the bluff. It is estimated that
the contact between the Torrev Sandstone and the terrace deposits is at an approximate elevation
of 25 feet (M.S.L.), making the thickness of the terrace deposits approximately 70 feet. These
deposits consist of tan to reddish brown, medium dense. fine to medium grained, uncemented to
poorly cemented sands. It appears that fill exists behind the upper retaining walls and its maximum
depth is estimated to be on the order of 15 in depth.
CONCLUSIONS AND RECOMMENDATIONS
Based on the findings and observations presented above, it is our opinion that the southern upper
retaining wall is structurally distressed and the residential structure on the subject property as well
as the residential structure at 660 Neptune are in imminent threat of failure. This opinion is based
on our observations of the visible crushing of the vertical columns at the tieback locations and the
associated relaxationldetensioning of the tiebacks. severe cracking/splitting of the two southernmost
vertical columns and the recent separations of the existing upper retainine wall. brick decking. and
fencing. These separations indicate that the wall is moving laterally (westward). in addition. the
recent separation approximately 3 inches wide has occurred between the existing slope materials
and the base of the upper retaining wall which results in a loss of passive pressure. It appears that
the separation is a result of the exisitng slope backfill materials settling/compressing and/or
downhill creep.
Based on the above, it is our opinion that the potential for structural failure of the wall is imminent.
It is our opinion that if no work is performed to repair the existing upper retaining wall (southern
678am gm
Ms. Diane Langager & Mr. Hans Jensen
City of Encinitas
December 14, 1998
Page 4
half), the residential structure on the subject property as well as the residential structure on 660
Neptune will be in imminent danger of failure.
In order to restore the upper retaining wall and lower seawall to its originally designed condition,
it is recommended that the following repairs be performed immediately.
Lower Seawall - Replace the existing tiebacks affected by corrosion with new
tiebacks. Said tiebacks should be double corrosion protected.
Construct a concrete gradebeam between the columns at the new
tieback locations. We recommend that the tiebacks be a minimum
of 40 feet in length The tie backs should be designed for a maximum
bond stress of 12 pounds per square inch.
Upper Retaining Wall- Install an additional row of tiebacks near the bottom of the wall and
construct a reinforced concrete waler. The additional row of tiebacks
should be designed to replace the existing lower row of tiebacks.
We recommend that the tiebacks be a maximum of 40 feet in length.
The tie backs should be desie ned for a maximum bond stress of 12
pounds per square inch. The existing wood/timber columns should
be repaired by installing corrosion protected steel channel splints.
Mid Bluff Wall- It is recommended that portions of the mid bluff wall be re- braced
using treated wood members. It is further recommended that the
overall hieght of the backfill behind the wall be reduced
approximately one foot in order to reduce the loading on the wall.
Some of the vertical wood/timber may need to be replaced also,
however we recommend that the walls condition be evaluated in the
field by the design engineer during construction.
679aw gm
Ms. Diane Langager & Mr. Hans Jensen
Citv of Encinitas
December 14, 1998
Page 5
If you should have any questions or require additional information, please call us at (760) 633 -3470.
Sincerely,
SOIL ENGINEERING CONSTRUCTION, INC.
Robert D. Mahony, E. 554, C.E.G. 847
Principal Enginee
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c: Mr. Lee McEachem, California Coastal Commission
Mr. Jack Lampl, 678 Neptune Avenue
Mr. Bob Trettin
67Pary gw
ohn W. Niven, R.C.E. 57517
Project Engineer
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NITCHAEL W. HART
ENGINEERING GEOLOGIST
File No. 183 -95
February 6, 1995
Accutech Consulting Engineers
9540 Waples Street, Suite F
San Diego, CA 92121
Attn: Mr. Robert J. Randall
Subject: Residential Property
678 Neptune Avenue
Encinitas, CA
.GEOLOGIC RECONNAISSANCE
Gentlemen:
In accordance with our agreement I have completed a geologic reconnaissance of the
sea -bluff located west of the subject residence.
The results of this study indicate that the bedrock units underlying the bluff consist of
Quaternary -aged marine terrace deposits and the Eocene -age Torrey Sand. The results
of this study indicate that both of these units have the capability, from a geologic
standpoint, of providing satisfactory support for the walls provided foundations and tie-
back supports are properly designed.
If you have anv questions concerning the findings and conclusions of this report.
please contact the undersigned at your convenience.
Very truly yours,
�PEL ty y
r
\
Of�5
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NO CEG706
CERTIFIED
4
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ENGINEERING
Michael W'. Hart
GEOLOGIST
NSA P. Greg
CEG 706
F„_ c!
2 cc addressee
P.O. PDX 361' -'27 • SAN I)IEGO. CALWORNIA.92196 • PHONE'FAX if, 191 714672
GEOLOGIC RECONNAISSANCE
Purpose and Sco
This report presents the findings of a geologic reconnaissance of the sea -bluff located
west of the residence at 678 Neptune Avenue in Encinitas, California (Figure 1). The
purpose of this study was to describe the engineering geologic characteristics of the
sea -bluff and to comment on the suitability of the exposed bedrock units as foundation
materials for the proposed retaining walls.
The scope of this study included geologic mapping of the sea - bluff, examination and
geologic logging of an exploratory pit located near the base of the bluff, and a review
of aerial photographs and readily available geologic literature. The scope of work did
not include an evaluation of the stability of existing retaining walls or the sea -wall
located at the base of the bluff.
Site
and Project Description
The
site consists
of a
gently easterly sloping residential lot with frontage of
approximately 50 feet along Neptune Avenue. The rear yard and patio lie near the top
edge of an approximately 90 feet high sea -bluff that is supported at the base by an
approximately 20 feet high sea wall constructed of reinforced concrete beams and
timber lagging. The upper 70± feet of the bluff is partially supported by two tiers of
timber retaining walls. The approximate northern half of the two upper walls failed
in January of 1995 resulting in a loss of the surficial soils and ground cover, a portion
of the rear yard that was supported by the upper -most wall, and a loss of backfill soil
behind the wall located at mid - slope.
It is proposed to replace the failed walls with engineered tie -back wall systems. It is
understood that Accutech Consulting Engineers is currently evaluating several wall
design options and are also performing geotechnical studies to determine soil strength
parameters for foundation design.
General Geoloav
The site is underlain by Pleistocene -age marine terrace deposits that are correlated with
the Lindavista Formation and the Eocene Torrey Sandstone (Wilson, 1972). The
nearly horizontal contact between these two units occurs approximately 17 feet above
the current beach level, or three feet below the top of the sea -wall (Figure 2).
The Torrey Sandstone consists of dense, moderately well- cemented light grey to nearly
white medium - grained sandstone. This unit forms the near - vertical lower portion of
3
i the sea -bluff that is now protected from marine erosion and supported by the
previously described sea -wall. The overlying Terrace deposits consist of compact but
essentially uncemented and nearly cohesionless medium to coarse - grained sand.
Approximately 300 feet north of the site, the Torrey Sand is overlain by a thinly -
bedded clay shale unit that has contributed to large -scale translational landsliding in
that area.
In order to determine if the shale bed was present on site a shallow observation pit was
excavated near the top of the sea -wall (Figure 2b). The top of the Torrey Sand was
exposed in the base of the excavation and consisted of dense, well- cemented medium -
grained sandstone. An oblique aerial photograph taken in 1971 prior to construction
of the sea -wall provides further evidence that the slide -prone clay shale unit is not
present along this section of the coast (Figure 3).
Bluff Recession
A comparison of oblique and vertical aerial photographs taken in 1928, 1953, and
1971, as well as other photographs of adjacent areas, indicate that during the period
between 1928 and the present numerous bluff - failures have occurred, chiefly in the
terrace deposits. There are at least three principal factors that significantly affect bluff
stability in the immediate area of the site:
1. The presence of weakly cemented to uncemented cohesionless sands.
4
2. The presence of high, excessively steep slopes.
3. Periodic blockfalls within the Torrey Sandstone that do not allow the
overlying terrace slopes to equilibrate with their environment.
It is also likely that groundwater is having an increasing adverse effect on unretained
slopes as seepage along the contact between the permeable terrace sands and the less
permeable Torrey Sand increases with increasing development and water usage east
of the bluff.
A determination of the average amount of bluff - retreat was not made because bluff
erosion on -site and on adjacent properties has been or will be arrested by sea -walls and
existing or proposed mid -slope retaining walls. In order for these walls to continue
to protect property from erosion they must be properly designed and equally
importantly, have a regularly scheduled maintenance program.
Faultine. Local and Recional
Published geologic maps (Wilson, 1972) indicate that the closest faults to the site are
minor faults that cut the Eocene aged Torrey Sandstone. These faults are relatively
common and may be observed in the sea -bluff south and north of the site. Since the
faults are not known to affect sediments younger than Eocene age and typically have
displacements of only a few feet, they are not considered seismic hazards.
5
The closest active fault is the Rose Canyon Fault that lies approximately 2 miles off-
shore. Recent studies have shown that the Rose Canyon Fault is capable of producing
an M 6.5 earthquake. Such an event on this fault or other regional active faults in the
southem California area could subject the site to moderate to severe seismic shaking.
Conclusion and Recommendations
1. The results of this study indicate that the terrace deposits consist of massive to
thinly- bedded light brown, medium - grained sands. Cementation is generally very light
to absent, especially in the lower portions of the bluff. Based on visual observations
of that portion of the bluff recently exposed by the surficial slope failure, the lithology
of the terrace deposits is generally uniform from the bluff top to the contact with the
Torrey Sand. Interbeds of clav, silt, or conglomerate, were not observed on site or
on adjacent properties.
2. It is concluded that there are no geologic structures present that may represent
unusual stability or construction problems. The wall contractor should be aware that
caving conditions caused by the presence of cohesionless sands may be encountered
during drilling of tie -backs and that groundwater may be encountered in some of the
excavations and may exacerbate caving conditions.
3
3. Poor surface drainage is a major cause of bluff instability. Therefore, it is
recommended that all surface and roof water be directed via swales or subsurface
drains to the street. It is recommended that roof gutters, if not already in use, be
installed on the residence.
4. It is recommended that existing large -leaf iceplant be removed and the slope
revegetated after wall construction with a mixture of drought- tolerant plant species
with variable root depths. Irrigation of slopes should be only on a temporary basis in
order to allow plants to become established. It is recommended that a landscape
architect be consulted to provide recommendations for suitable plant materials and
irrigation.
7
References
Kennedy, M.P., 1973, Sea -Cliff Erosion at Sunset Cliffs, San Diego, California
Geology, Vol. 26, No. 2.
Kennedy, M.P., 1975, Geology of the San Diego Metropolitan Area, California, Bull.
200, California Division of Mines and Geology.
Kuhn, G.G. and Shepard, F. P., 1984, Sea Cliffs, Beaches, and Coastal Valleys of San
Diego County, Univ. California Press, p. 193.
Wilson, K., 1972, Eocene and related geology of a portion of the San Luis Rey and
Encinitas Quadrangles, San Diego County, California, unpub. M.A. thesis, Univ.
of California. Riverside.
Aerial Photoaraohs
U.S. Department Agriculture, 1953, 8 M 95 & 96
San Diego Countv, 1928. 37 -172
Aerial Fotobank, 1971, Low -angle oblique, neg. 50, 475.
I:l
N n
Et
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Scale: 1 " = 200'
D ��• t 1
Z
D
rn _
D
SITE PLAN AND GEOLOGIC MAP,
NEPTUNE AVE. PROPERTY, ENCINITAS CALIFORNIA
LEGEND
Qls- - - - - -- Landslide
Qt - - - - - -- Terrace Deposits
Et - - - - - -- Torrey Sand
C
C
Figure 1
so—
60—
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at
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o �
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see Fig. 2b
20
Et Sea Wali
0
Ap
Figure 2a, Structure section through north portion of bluff
-slough
Qt
Et
Figure 2b, Detail through lower part of bluff and observation pit
Scale: 1 = 10'
Figure 2a & b
IN, F
MobOAN
F17W!
Figure 3. 1971 photograph of sea-bluff prior to construction of sea-wall
showing massively-bedded nature of Torrey Sand and absence of clay shale
unit on lower, vertical portion of bluff face, (arrow).
Ar fj
Convents C
�i NOAP .,
April 19, 1985
Mr. James Swift
527 Encinitas Boulevard
Suite 2C6
Encinitas, California 92024
Subject: Proposed Sea :tall
678 Neptune Avenue, Encinitas
San Diego County, California
(CCI Project No. 85- 2138 -01)
-' Dear Mr. Swift:
Presented herein are the results of our geotechnical exploration per-
- formed for the proposed sea wall to be lccated alony your property.
This work was performed in accordance with our proposal dated March 7,
1985.
Thank you for this opportunity of working with you on this project. If
there are any questions or if you need further assistance, please do aot
hesitate to contact us.
Yours very truly,
CONVERSE CONSUL�TAIfT.S,,.INK.
CDennts L. Iannan- C.E.C. 953
Managing Vice President
RYR /JBR /DLN:bl
-' Dist: (3) Addressee
r
cti canwiftwo& aw.
M5 worn.. sn.w
3a A CyWn 8706
T 1714) 781 -2414
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1 i
TAaLE OF CONTEIITS
PAGE NO.
IKTRODUCT1011 ........
SURFACE ANT, SUBSURFACE CONDITIONS I
Figure 1. Vicinity Map ... .............................. 2
Photo I
nd Soi ..... ............................... 3
Geology ud Soils " " "
........ ............................... 4
GROUNDWATER 6
SLOPE STABILITT ....................
Photo 2 6
Figure 2, predominant Nodes of Slope Failures 9
CONCLUSIONS AND RECOIMENDATIONS 11
Drainage ............
Sea Hall ....•.•..•...........
Anchored ............... ............................... chored Wall 12 .........
... ...............................
Foundation Support ............ 1T..... 13
.....................
Tall Oralnage ............ ...............................
Tiebacks 14 14
...........................
DESIGN AND CONSTRUrTION REVIEW 15
CLOSURE....................... ............................... IE
REFERENCES.................... ............................... 18
DRAWING 1, Geology and Slope Stability Analysis Follows Text
APPENDI7 A - Field Exploration and
Laboratory Testing Al f A2
esiiiiisiim o...rant wa
i
i
INTRODUCTION
This report presents the results of Our subsurface exploration, surface
upping, laboratory tasting and analyses, and provides 9eotechnical
j recogmendations for foundation design and construction of the proposed
se• wall. The sea *all will be located at the base of the property along
'1 the sea cliff in 'he vicinity of Encinitas Beach County ►ark (see Figure
1, following page for vicinity nap).
' The Proposed sea w417 guy be on the order of 50 to 70 feet in length, and
may be about 15 to 25 feet In height, depending upon the option selected.
A reinforced concrete will is presently planned. He understand that the
construction cf a wall at the base of the cliff has already started, but
had to be stopped pending additional geological engineering studies.
i
The Purpose of this study was to Obtain surface and subsurface data to
enable us to Provide preliminary rccoraendations for foundation support
r
and construction of the proposed sea wall. The scope of our exploration
included reviewing rrevious data related to sea cliff and bluff stability
in the area, Surface mapping, surface soil Saagling, laboratory testing,
analysis, and preparing this report. This engineering report Contains
'T
our findings, conclusions, and recomrndations on the following;
_1
1. Slope stability
1
2. Drainage, and
A
3. Sea wall
1
J
The scope of our stud) did not include remedial measures to stabilize
the bluff (i.e.. upper 85t feet of the slope), or to Investigate
historical coastal recession.
.'
J
SURFACE AND SUBSURFACE CONCITIM
'j At the time of our field exploration on 20 Marts 1985, $'be site had a
j 15 -20 foot high bedrock sea cliff (see Photo 1), capped by an 85± -foot
high bluff. (The ten 'sea cliff' refers to the near vertical slope
F1
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immediately above the beach, and tht term "bluff' refers to the less -
steeply sloping land above the cliff tying between the Cliff and level
land above.) Beach deposits consisting predominantly of cobbles lay at
the base of the sea cliff. Elevations in the beach area ranged frcc:
abcut : to 10 feet above mean sea level (MSL). The sea cliff stands a-
inclinations, ranging 'run 80 to 85 degrees from the horizontal, and the
blu" area averaged about 50 degrees from the horizontal.
Tinier and baard retaining wall, have beer constructec at four dif'erent
levels Within 'he bluff area above the sea cliff. The two at the base
of the bluff are approximately 7 fee: high and extend across the entire
width of the croperty (50: feet). A smaller (5: foot) retainin wall,
located approximately at mid -bluff height, extends laterally I5 -2C feet.
Thesd three .ails nave minor amounts of fill placed behind them and are
also used as sippart for a wocden stairway which externs from the rear
Yard dowr to the beach. The berth retaining wall, located rear the top
of the bluff, is approximate'y I1 -12 feet Sigh and extends across the
wioth o° cne oroperty.
The retrains of an old 'tram' descending to the beach was observed along
the northern property line, and the beginnings (tied rebar) of a sea
wall was observed ainng the entire length of the sea cliff. Two 6 -inch
diameter plastic subdrairs were noted at the interface of the sea cliff -
bluff zone, and were discnarg,ng water at the _ime of our field explora-
tions. The bluff area, within the property limits, conspicuwsly has
pore vegetation than adjacent areas. Vegetation consists predominantly
of rosea iceplant with a tew small Struts and trees (acacia )atafolia
and myraporum ?).
Geology and Soils
The site lies within the Peninsular Pange Ge.7morphic Province which
extends from the LCs Angeles basin to the southe" end of Baja, Cali-
fornia. The property lies within the narrow coastal plain of San Diego
Cwnw Cw.r.r r
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I
(
5
( County which consists of several mesa -like surfaces. These surfaces
represent wave cut terraces that were eroded from the underlying,
gently - inclined sedimentary rock of predominantly, Eocene age (38 -55
million years).
The geologic units encountered at tN1 site include, fros youngest to
Oldest- artificial fill (Af), beach deposits (0b), terrace deposits
(010, and bedrock assigned to the middle mrarEer of the Santiago Forma-
tion (Tsb). These units are delineated on the Geologic Map (See Drawing
1, followinj text). :t was beyond the scope of this report to investi-
gate the nature (soil, type, relative state of compaction, and quantity)
of the fill materials at the site.
In general, the beach deposits were frrund to consist predominantly of
gravel to cobble -sized material near the sea cliff grading to sandier
materials towards the ocean. Ioxdiately above the sea cliff and
covering alms; all the site are indis'.inctiy to weakly stratified,
poorly consolidated sands of the Lower '-Idistocene Linda vista Formation
(Terrace Deposits;. At this location, the deposit is approximately 80
feet in thickness. the formation ranges from reddish brown in color
near the top of the cliff grading to ! white. light yellow color at the
base. The upper portion is slightly more cemented and contains some
clay, whereas the bottrm portion consists predominantly of fine to
medium sand possessing little natural cohesion. Surficial soil cohesion
is derived predominantly from salts obtained by off -shore breezes. The
sands, despite their lack of cohesion, are expected to be in a naturally
dense state beneath the site where they have rot been disturbed by
erosion, ve3etation, or man's activities.
The Eocene -age Santiago Formation (sandstone member as defined by
Wilson, 1972), comprising the entire height of the sea cliff, consists
generally of fine- to medium - grained, white to pale gray, massive, soft
r� d.rr we
r
6
slightly Weathered, slightly cemented sandstone. The general lnclina_
tlon of the The
Formation in this vicinity is known to be predo-
minantly subhorizontal with gentle dips to the west and north (Wilson,
1972 and 6eoer, I982). Two prominant Joint sets (fracture systems) were
observed. One set consists of generally vertical to steep - dipping
joints trending subparallel to the cliff face (North 30 East), and the
1 other trendiro generally parallel With
} the cliff face (North 15 West)
dipping steepiY westward (75' -85'). Typically, these Joints are medium
to very widely spaced (1' to 6'.). The joint set parallel to the cliff
face tends to play a controlling _role in sea cliff stability, especially
when those joints are moderateiy spaced (1 -2 feet)
7
1
GRDUNOWATER
During our field exploration on March 20, 1985. We observed seepage at
the contact of the terrace sand deposits and the sandstone bedrock.
a Based On studies by ethers (Leighton and Associates, Drew K. Saint and
Gerry Kuhn) in the Encinitas area, we understand that the location of
seepage is structurally controlled. The seepage occurs primarily at the
T contact between the Pleistocene sands and the Santiago Formation. The
s groundwater apparently originates from natural recharge infiltration of
irrigation and seepage pit or leach line ester associated with develop-
s
f sent inland from the site. It is understood that
groundwater has been
rising. And seepage has increased with additional developments.
1
1
SLOPE STABILITY
1
Based
on m r observations, the
principal
modes of cliff failure
of rock topples and falls in
the cliff,
consist
and slumps in the bluff
J
Falls
occurring as thin blocks
area.
(about 2 fee: thick) break loose from
cliff
masses
and fall onto the beach
of --tat
(see Photo
the
2). Block topples consist of
rock overturn about a pivot
point. Jointing
parallel -d
i
■
Cm— e—rr tie
J
73
l
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■
I
8
the cliff face and rave action are the two principal factors contribut-
ing to sea cliff failure. Direct attack of the cliff by rave action
leads to subsequent undermining of large slabs of pointed bedrock. In
the bluff oortfon of the slope, the failures generally consist of sur-
ficial slumps and flows. These failures are usually activated by
spiking or saturation of the terrace sands or results from the under-
mining effects of the sea cliff block failures (see Figure 2 for predo-
minant modes of slope failure). The bluff portion of the property con-
sists of a very irregular, undulating configuration that has resulted
due to rodent digging and undermining, sloughage of the bluff fsce
sands, rilling by runoff during storms, slippage of vegetative ground
covers, and wind erosion.
Shepard and Grant, 194% Lee, Pinckney and Bemis, 19:6; and Kuhn, 1978,
list numerous factors as being involved in sea cliff and bluff reces-
sion, including the following:
' Saturation of sediments froo rainfall and irrigation;
` Removal of sea clitf support below the bluff;
' Pedestrian traffic, burrowing activities of people, rodents,
and dons;
' Coastal configuration;
Solubility of rocks and rock cements;
He:ght cf cliffs;
Direct attack of the cliff by wave action:
The absence of an adequate buffering beach;
The action of wind and wind- transported sand;
Wave- action widening of bedrock faults and joints, with
preferential remval of incompetent material by wave action;
Development and collapse of sea eves;
Seepage of irrigation and groundwater;
irrigat%n along the top of the cliff;
Runoff from structures built on top of cliffs, nonnatural
vegetation, the degree of bedrock fracturing, and degre
of indurati:n (consolidation);
eawrrw, b+aww+a wt
is
1
INCIPICNT FAILURE
.
•. ...TERRACE SAIOS '
1
'. .. ..
jIUF
.
BEDROCK
_ }�
FAILURE OF WEAKENED SEA CLIFF AND
INITIATION OF FAILURE IN BLUFF FACE
7
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ORIGINAL BLUFF
TERRACE SUDS
E
FROGAESSIVE FAILURE— 3
j
OF BLUFF %'J�
- .-
. ...
r
DEBRIS REMOVED 11 ,17 3
B Y
s `
1 .
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-. -..
- DR
BEO CK
'
WAVE ACT IOM I
N
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RECESSION OF BLUFF FACE BY
COM INATION Of SEA CLIFF
AND BLUFF FACE FAILURES
.I
PREDO +INMT NODES OF SLOPE FAILURE
Fv® SIA NRu • .re •.
OB REFTUNE Art„ ESKTAITAS, SM DIEGO CofFY. C16LIFMLA
FOE: JM SWIFT NI- 71JB -01
® Converse Consultants.,`'��—
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' Presence or absence of a shallow wave -cut bench; and
' The presence or absence of a sand beach and kelp graving
off shore.
10
I
1
Some of the major factors contributing to sea cliff recession at this
site include:
Weight
Cohesion
' The height of the cliff (100'±);
7
Low cohesion in the bluff materials;
1
' Direct attack of the cliff by wave action, including the
grinding action created by the gravely bead: deposits;
100
• Seepage of irrigation and groundwater; and
' Jointing parallel to the cliff face.
ISO
35
The stability of the bluff was analyzed in consideration of common types
400
of failures that occur in these materials. Stability calculations were
performed on a microcomputer using the TSLOPE program and Spencer's
..�
method of slope stability analysis. Shear strength parameters were
.1
selected based on our laboratory tests, and the test results of ot.4er
investigators in the same formation (Leighton i Associates). The
+
following values were selected for stability analysis:
I
1
Unit
Weight
Cohesion
Friction
'
Material (pc f)
(psf)
Angle °
Upper Terrace Sands 125
100
34
Lower Terrace Sands 125
ISO
35
Bedrock 11-
400
36
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I
I1
( Our analyses indicate that the bluff area is meta4table (safety factor
aPProximately equal to 1) in its present configuration. Wher. we added a
wail pore pressure ratio (0.1) to simulate soave seepage force due to
rater infiltration, the safety factor became less than 1 (see Drawing 1,
fol' .ti. teat, for the results of the slope stability analysis). The
1 form o- e to a moderate earthquake would also reduce the safety factor
below 1.
-� CONCLUSIONS AND REC"ENDATI0NS
Based (,n our observations and analysis, it is our conclusion that the
bluff and sea cliff are marginally stable (Factor of safety approaching
1 or less). Further deterioration of the sea cliff face may underline
the toe of the bluff and lead to the bluff failure, and•undemine the
support of the residence. We recoomend that immediate steps be taken to
stabilize the sea cliff and the bluff. No rill should be placed on the
Slope to obtain larger garden or other usable space. Specific recommen-
dations for drainage and sea wall construction are presented in the
following portions of the report. No specific slope stability measures
are presented for the bluff since this work was beyond the scope of our
study.
Drainage
Land failures are caused mainly by oversteepening of the slopes and
grouMwater penetration of the sediments and into fractured sandstone.
Historical record shows that the majority of failures occurred following
Periods of heavy rainfall. Water must be diverted from the bluff and
cliff formations to minimize potential instability.
All drainage from the top of the bluff, including the backyard of the
house. Shand be directed toward the street. The existing horizontal
drain pipes located near the contact of the bedrock and terrace deposits
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1 should be extended over the proposed sea cliff Wail. Additional hori-
zontal drains should be Installed, as necessary, in seepage areas to
minimize watzr flaring across the face of the cliff.
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Sea Vall
-. The sea cliff Is being eroded by wave action and groundwater seepage,
which creates instability. The cliff erosion can be retarded by con -
strictirg a sea wall. The sea wall may be designed for two objectives:
I. Prevent erosion at the base of the cliff by prevercin/ t..Se
wave energy from pounding the cliff.
-' 2. Stabilize the slope by confining the bedrock and by minimizing
joint opening and weathering.
r in our opinion, the preferred type of sea wall is an anchored, rein -
forced concrete wall supported on cast -in -place piles. Other Walls such
as reinforced concrete gravity wall may also be used, but their life
expectancy may be relatively shorter. Any will sho-ild preferably meet
the ..bove two objectives, and its foundation should be sufficiently deep
or adequately protected to prevent undermining by wave erosion. Good
drainage should be provided behind the wall to prevent groundwater
pressure buildup, or the wall should be designed for such a pressure.
Anchored Ma 11
We envision a wall about 20 to 25 feet high, 1 to 2 feet thick, and
extending over the entire length of the property. The base of the wall
Zmould be about 3 feet below low sea level or as recommended by the
oastal Engineer. The wall would be supported on 30- or 36 -inch dia-
reter cast - '"lace piles penetrating the bedrock at least 20 feet. The
lateral earlr pressure at the upper part of the wall would be resisted
by tie back anchors and the back of the Wall would be
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backfilled with drain gravel to prevent hydrostatic pressure build up,
or the wall designeti for such a pressure. Specific recommendations for
j foundation support, wall drainage, and anchor follow.
Foundation Support
Drilled, cast -in- place, concrete friction piles are recomended for the
i support of the retaining wall. The piles should develop their load
-� resistance in the bedrock. A skin friction value of 3000 psf may be
i used in design; however, it is expected that the requirements for
lateral load resistance will govern tfe design pile lengths. The piles
i should be spaced not less than 3 pile diameters apart, center -to- center.
The amount of pile lateral resistance will depend on the lateral dis-
placement and bending of the piles. Table I presents the allowable
' lateral capacities for 30- and 36 -inch diameter cast -in -place piles.
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-� TABLE I - LATERAL LOAD PILE DESIGM CRITERIA
,
N
Cl CMA-ft & rc
F LED HEAD
Pile Diaceter
30 Inches 36 Inches
Lateral Capacity, P (kips)
100 130
MAximum Moment (ft -tips)
4.2 P 1.9 7
Depth to Maximum Moment (ft)
7.0 8.5
'
Depth to Zero Moment (ft)
18.0 21.0
A
I. Laterai capacity is based on 1/3 -inch lateral deflection
at pile COP and may be increased by 33 percent or short
durations of loading, which
includes tha effect of wind
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or seismic forces.
-�
2- Moment is for the horizontal
load, P. applied at the pile
CAP; if the horizontal load
is in kips, the moment will be
1
in foot -kips.
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3. Values are for piles longer
than 20 feet.
A. Depth is measured below the
pile cap /wall base.
N
Cl CMA-ft & rc
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1 Severe caving is not expected to the drilled pile excavations, provided
that a positive hydrostatic pressure is maintained In the hole. The
7 placing of steel and concrete for the piles will have to be performed
below the groundwater level. The placement of concrete below water
should be performed by forced pumping of c:ncrete through a tremie.
Wall Drainage
(
If the design pressure does not include hydrostatic pressure, the
retaining structure shoula be well - drained with a minimum 18 -inch thick
i (horizontal distance) layer of filter gravel placed behind the wall amd
-� relieved bw a drainage pipe placed along the base of the wall. The
I filter gravel should conform to a Class 1, Type A filter drainage
material per Caltrans Specifications (latest edition), Section 66- 1.025,
and should be protected from siltation of the overlying wall material by
a suitable high - strength, tear- resistant, nonwoven filter fabric having
an equivalent opening sieve size (EQS) of 70 -100. A subdrain pipe
placed behind the wall should consist of a minimum 4-inch diameter,
noncorrosive drainage pipe having maximum 3/8 -inch diameter hole perfo-
rations. The pipe should be surrounded by at least 6 Inchcs of the
recommended filter gravel.
We also recommend forming a gunited '1P ditch at the top of the wall to
■imimize surface or rainwater infiltration behind the wall. The exist -
i719 plastic pipe drains should be extended over the face of the wail.
Tiebacks
We recumend that the tieback retaining will be designed for an active
earth pressure of 45 and 80 psf /ft of depth below tie top of the wall
for drained and urdrained conditions, respectively. The earth lateral
Pressure against the retaining will will be resisted by tiebacks and
We lateral resistance. The tiebacks, which rey be on the order of 40
to 50 feet long, would be embedded in the bedrock.
d.� aArr taw.
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y
We recommend that the tieback inclinations be at least 15 degrees from
horizontal; the tieback angle should not exceed Q degrees. The first
20 feet (unbonded length) of the tieback should not be considered for
the Calculation of shear resistance. A minimum stressing length of 20
feet should be used. The skin friction resistance of the bedrock for
estimating the tieback length and design load is 3000 psi The tieback
capacities must be based on load tests. The minima spacing recommended
between tiebacks is 7 feet, or three times the anchor hole diameter,
whichever is greater, and the maximum aliowable load is 200 kips per
tieback.
All tiebacks should be tested to loads 1.5 to 2 times the design loads;
we will be available to establish a test load program at the time of
construction. Because of the corrosive environment of- the project,
tiebacks should be well protected against corrosion; a double or triple
'1) corrosion protection should be used. To minimize caving of the poorly
i cemented bedrock zone during construction, it is advisable to keep the
tieback hole diameter smaller than 20 inches.
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DESIGN AND CONSTRUCTION REVIEW
This report has been prepared to assist the Owner and Enginetr in the
T desiyr of the proposed coastal
� protection. Prior to construction, it ti
recommended that this firm be provided the opportunity to review the
i design drawings and specifications in order to ascertain that the
recommendations contained in this
report and those used In the final
s design are applicable to the site conditions.
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It is also recommended that our office be retained to provide services
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with the design concepts, specifications, and recommendations, and to
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gym, e.wa na
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Bidding contractors are urged to study the bedrock conditions along the
1 coast, and to determine to their own satisfacr:on the subsurface condi-
tions that may be encountered by appropriate independent pits, borings,
.� or other methods prior to submitting bids.
This report has been prepared exclusively for Janes Swift and his
consultants for specific application to the proposed site Coastal
improvements described in this report. The use of this report for other
purposes is prohibited.
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Provide advice regarding design changes In the event that the site and
subsurface conditions differ from those anticipated prior to the start
ii
Of construction.
CLOSURE
The findings and recommendations of this report are based on the results
of the field exploration and laboratory Letts combined with interpola-
tion and extrapolation of soil and bedrock conditions observed along the
coast. The recommendations represent our best professional judgement as
to
the procedures to be followed in design and construction based on the
da U obtained and the planned construction.
Professional services in connection with this geotechnical report have
complied with generally accepted practice in the fields of soil mech-
anics, foundation engineering, and engineering geology. We mute no
.m
other warranty, either express or implied. If conditions change prior
JS
to the actual construction, or if conditions are encountered during
construction that appear to be different from those fount during our
exploration, we shou.d be notified immediately so that appropriate
modifications of recommendations can be provided, if needed.
Bidding contractors are urged to study the bedrock conditions along the
1 coast, and to determine to their own satisfacr:on the subsurface condi-
tions that may be encountered by appropriate independent pits, borings,
.� or other methods prior to submitting bids.
This report has been prepared exclusively for Janes Swift and his
consultants for specific application to the proposed site Coastal
improvements described in this report. The use of this report for other
purposes is prohibited.
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Thank you for the OPPOrtunity to be of service.
CONVEXSEECCMLILTAKTS, IMC.
Y&Cqu I °- I
ROY. R.C.E. 31386
SeniO: Engineer
Dennis L. Narnan, C.E.E. y5;
Ilaeaging Vice President
AOb -i-t W. Ruff, C.E.G. 1165
Pr01eCt Geologist
Cb— C.Mw we
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REfETiENCES
Hertlein, Lec George, and Grant, U.W., 'Geology of the Oceanside /sdn
Diego Coastal Area, Southern Cali'jrnia' in California Division of
Mines Bulletin 1::, Chanter I1, Article 4—'954.
Kuhn, Gerais G.. "Coastal Zone Geology and Related sea Cliff Erosion:
San Diegu,to River to San Elijo Lagoon, San Diego County,
California-, unpublished manuscript, 1978.
Lee. Louis; Pincrnoy, Charles; Bemis, Charles. 'Sea Cliff Base Erosion:,
American Society of Civil Engineers National Water Resources and
Ocean Engineering Convent;on Preprint No. 2708, 1976.
Leighton and Associates, Inc.. 'SaPtilemental Geologic Report, 1610
Neptune Avenue, Leucadia. San Diego County, California', Report
dated 23 August 1978. Project No. 477345-02.
Leighton and Associates, Inc., 'Geotechnical Investigation, Condominium
Bluff Site. Southwest Cornzr 4th and H Streets. Encinitas, Calif -
ornia". Report dated 27 March 1979, Protect No. 478062 -H.
Leighton anc 4ssociates. Inc., 'Preliminary Geottchnical Investigation
Of Lands'ide at Seventh ano T4 :rteenth Streets, Del Par Bluffs,
City of Oel Mar, CcunLy of San Ciego, Ca!irernia', Report dated 30
January 1970. Project No. 4;8008 -1.
Maloney, r,,,;, 'Codsta! Erosion and Sea Cliff _tabi7ity, Self- Realiza-
ticn = ellowsnip Church, Encinitas, California', Report dates 5 Kay
Sa'.rt, P.R., 'Hydregeoicgy end Groundwater Cord'tions Related to Sea
Cliff Stability r� Self Realization ie:lws!iip Property, Enci-
nitas', Report dated !7 Mav 1980.
Shcoaro, c. P. and Grant. U.S. :';, 'Uavr 5r"� n along the Southern
Cai.ifornia Codst', 5u1'et+•.of Lne ;eo'wical Society of Aeierica,
Val. 5E, PP. 919 -926, !94'.
Weber, iiaroid F., jr.. ' =event S1coe Failures, Ancient Landslides, and
Related GeClOgy Of t. ".e Morth- Central Coastal Area, San. Diego
Ccurry, Califorr,a', California Division. of Hines and Geology,
Open -f" a Report 82 -:' LA. 1,922
Wilson, yerneth Lee, 'Eocene and Related Geology of a Portion of San
Luis Rey and Encinitas Cuadrang!es, San Diego County, California';
N.A. thesis, University of California Riverside, 1972.
conowso r+ftuwa aw.
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APPENDIX A
FIELD EXPLOPAT ;ON AND LASORATORf TESTING
Owe cmmw t r
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Two progressive direct shear tests were parfo. on relatively undis-
turted samples. The samples were ;naked and sheared under an average
rate of strain of about 0.01 inch /minute under normal loads ranging
between 2 and 8 kips /sq. ft. The sandstone sample from Trench 3 yielded
a friction angle of 36 degrees and an apparent cohesion of 450 psf, and
t!e :errace sand from Trench 2 gave a friction angle of about 37 degrees
with an ar,✓aeent cohesion of 240 psf.
Two parti,le size analyses were performed on :aeples from Trenches 1 and
2. The tests were performed in accordance with ASTM Test Method C136 to
determ•ne the gradation of the sand and arount of fines. The test
results, presented on the following page of this Appendix, indicate that
the :errace material is predominantly poorly dradeo, fine-medium sand,
with a low percentage of silt.
Cow ca-ww w. as
FIELD EXPLORATION AMC LA60rTAT0Rt TESTING
The field exploration included A site reccnna,ssance, surface mapping,
And Shallow trenching. Three s`al iow trenches were excavated by hand
tool eguroeent to depths of about 3 feet ;see Drawing 1 for trench
4
location). To obtrin re�atively undisturbed sanpies, the drive sapler,
lined with sample rings, was driven with successive drops of a haver.
Bulk samples were also obtained from the exposed ground surface.
Laboratory tests were conducted on representative samples for the
Purpose of classification and for evaluating the material ergi-reering
properties. Moisture content, density, shear, and gradation tests were
performed. Moisture content and dry density tests were performed
essentially in accordance with ASTM Test Method DZ216 to provide quali-
tative information regarding soil strength and compressibility. The
following results Were obtained:
Moisture Dry
Trench 6o. Content (i) Density (pcf)
1 2.2 -
2 4.0 94
3 15.4 100
Two progressive direct shear tests were parfo. on relatively undis-
turted samples. The samples were ;naked and sheared under an average
rate of strain of about 0.01 inch /minute under normal loads ranging
between 2 and 8 kips /sq. ft. The sandstone sample from Trench 3 yielded
a friction angle of 36 degrees and an apparent cohesion of 450 psf, and
t!e :errace sand from Trench 2 gave a friction angle of about 37 degrees
with an ar,✓aeent cohesion of 240 psf.
Two parti,le size analyses were performed on :aeples from Trenches 1 and
2. The tests were performed in accordance with ASTM Test Method C136 to
determ•ne the gradation of the sand and arount of fines. The test
results, presented on the following page of this Appendix, indicate that
the :errace material is predominantly poorly dradeo, fine-medium sand,
with a low percentage of silt.
Cow ca-ww w. as
s.— C —
CLAY— — + SILT - - -- SAND + GRAVEL
I' YIDIUY --� a NSi nNt• - -►�-
IOP SYN f1lE NUYe(t 710 1W IID 100 » l0 l0 ,p 1 I. 111 1 J
i I, I
W ( -; 1.• 1 _: �.I I .. !.. !'' I C I 1 1 I;� I 11 I I 1 .`J.
u -•'�, :, ►I ; ...�. I. �.I ;.:illl I�,,I I. � I, ..i �I � ! � ;..L_ I I i�. ; I� -,I' �II�� I
t � 1 _i. _� , I I I I f i ;I I, ► I ;I I� I I� f
77
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PA"TICLE DIAMETgR IN MILLIMETlRH MO I
s anal !. WMIA 1, KM I -r GRAIN -SIZE DISTRIBUTION CHART
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