HomeMy WebLinkAboutPD 05-17; LA COSTA DE MARBELLA; FINAL SOILS REPORT; 2006-07-07STONEY-MILLER CONSULTANTS, INC.
GEOTECHNICAL ENGINEERING & ENGINEERING GEOLOGY
GEOTECHNJCAL REPORT OF RETAINING STRUCTURE
EARTH\VORK AND CONSTRUCTION
LA COSTA DE MARBELLA LANDSLIDE
CITY OF CARLSBAD, CALIFORNJA
Prepared for:
City of Carlsbad
1635 Faraday Avenue
Carlsbad, California 92008
Prepared by:
Stoney-Miller Consultants, Inc.
14 Hughes, Suite B-101
lrvine, California 92618
Project No: 12567-10
Report No: 06-10227
July 7, 2006
14 HUGHES, SUITE B-101 IRVINE, CA 92618-1923 (949) 380-4886 • FAX (949) 455-9371
July 7, 2006
City of Carlsbad
1635 Faraday Avenue
Carlsbad, California 92008
Attention: Mr. Glen Pruim, P.E.
Mr. Skip Hammann
Project No.: 12567-10
Report No.: 06-10227
Subject: Geo technical Report of Retaining Structure, Earthwork and Construction
La Costa De Marbella Landslide
City of Carlsbad, California
Gentlemen:
This report presents the results of our geotechnical observation and testing services provided
during construction of the retaining structure at the La Costa De Marbella Landslide, located
near the 2800 block of La Costa Avenue, City of Carlsbad, California. The project extends
roughly east to west for a distance of approximately 270 feet along the right-of-way of La Costa
Avenue. The location and limits of the subject site are depicted on the attached Regional
Geologic/Topographic Site Location Map, Figure 1, and Plan Map of Retaining Structure
Improvements, Figure 2. The purpose of the repair work was to mitigate future damage and
restricted access to the La Costa Avenue right-of-way from the surficial landslide.
The plans utilized for the subject project are Sheets 1 through 3 of an undated set entitled "Slope
Repair -La Costa Avenue," prepared by RBF Consulting, Inc. oflrvine, California. The plan
set includes a title and detail sheet, as well as a 40-scale plan depicting the general limits of the
slope improvements and proposed final grading (Sheet 3), which was utilized as the base for our
Plan -Retaining Structure Improvements (Figure 2). In general, Figure 2 depicts the location of
caissons, tie-backs, constructed drainage, density tests and general limits of fill placement.
July 7, 2006
SITE DESCRIPTION AND HISTORY
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The La Costa de Marbella condominium property is located directly south of the east-west
trending five-lane La Costa Avenue, approximately 0.75 miles east of El Camino Real, within
the City of Carlsbad, northwestern San Diego County, California (Figure I). The property was
reportedly graded in 1973, and developed at an unknown date thereafter. A detailed site-specific
topographic map dated 2001 (see Figure 2), depicts the east/west trending development as
increasing in elevation from north to south, between approximately 40 to 110 feet above mean
sea level (a.m.s.l.). The northern boundary of the development fronts approximately 830 feet
along La Costa A venue, increasing in elevation from east to west between approximately 40 and
80 feet a.m.s.l., respectively. A north facing 40± foot high 2: 1 (horizontal:vertical) combination
fill and cut slope ascends from the south side of La Costa Avenue to a relatively level te1Tace at
elevation 90 to 98 feet a.m.s .l., upon which is situated a row of two-story condo units, detached
garages and an adjacent paved access roadway.
The La Costa de Marbella landslide reportedly occurred on or about March 11, 2005, and
resulted in the destruction or damage to 8 condominium units and associated detached garages,
centrally located within the development. The addresses of structures damaged by the slide
include 2407-A through -D, and 2405-A through -D. The above units were subsequently "red-
tagged" by City officials and remain un-occupied as of the date of this report. All utilities
servicing the buildings have been disconnected. While the head scarp and a majority of the
landslide mass are located on private property owned by the La Costa de Marbella development,
the toe of the slide daylights onto City-o\vned property within the southerly (east-bound) lane of
La Costa Avenue (see Figure 2). Approximately 200 feet of City sidewalk, curb, gutter, and
possibly underground utilities were damaged along the toe of the landslide as a result of its
OCCUlTence.
PROJECT DESCRIPTION
The caisson/tie-back retaining system was designed to protect the road in front of the landslide.
Construction of the retaining structure included the installation of one row of 33 steel H-Beam
caissons in concrete, with connecting near-surface tie-backs. Lagging was utilized between the
H-beams to a height of approximately 8 feet to 9 feet above design curb grade. An approximate
3-feet deep excavation was completed in front of the wall across its entire length, and a subdrain
system was installed. Backfill and surface drains were completed behind the wall to capture
future upslope surface drainage and provide further protection from the slide. Portions of the
roadway affected by the landslide were also removed and rebuilt. The construction took place
along the southern edge of the right-of-way of La Costa Avenue, at the toe of the La Costa de
Marbella Landslide, located within the City of Carlsbad, as depicted on the Plot Plan, Figure 2.
The diameter, total depth, and underlying seepage depth and conditions associated with each
caisson are presented in Table 1, Caisson Data Sheet. Caisson location, spacing, and
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reinforcement were determined by others. RBF Consulting provided civil engineering services
associated with surface drainage and drainage structures. Melchior Land Surveying Inc.,
provided survey data for the caisson installations, including information used directly or
indirectly to set caisson location, spacing and tie-back location. Testing Engineers of Carlsbad,
California provided part-time deputy inspection services for City of Carlsbad, during caisson
construction. A senior geologist from our office observed the caisson excavations, tieback
installation and testing, and backfill.
PROJECT DATA
A. Project Site: La Costa De Marbella Landslide, La Costa Avenue,
City of Carlsbad, California, as depicted in Figure 2
B. Client: The City of Carlsbad, California
C. Grading Plans: "Slope Repair -La Costa Avenue," undated, 40-
scale Grading Plan, Sheets l through 3 by RBF
Consulting, Inc. of Irvine, California
D. Retaining Structure Plans: Burnett & Young, Inc., "Permanent Retaining
Structure, Sketches and Specs," La Costa De
Marbella Landslide, Carlsbad, California, dated
June 9, 2005
E. Civil Engineer: RBF Consulting, Inc.
F. Surveyor: Melchior Land Surveying, Inc.
G. Grading Contractor: Erreca's Construction, Inc.
H. Caisson and Lagging Installation: Zamborelli Enterprises, Inc.
I. Tie-Back Installation: Zamborelli Enterprises, Inc.
J. Completion Date: April, 2006
The purpose of our geotechnical services was to: observe the excavation and construction of
caissons and tie-backs; perfom1 monitoring of tie-back tensioning and testing, to evaluate
conformance with the proposed design criteria, and to observe drainage placement and
construction over the length of the wall. Field personnel with Stoney-Miller Consultants, Inc.
(SMC) provided observation throughout the construction of the retaining structure. Field
engineering, analysis and monitoring services were provided during slope stabilization efforts.
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Our services were performed in general accordance with our Proposal No. S052247, dated
April 15, 2005, to City of Carlsbad. Key elements of the field geotechnical observations and
engineering monitoring services included the following:
• Geologic observation and mapping of excavations.
• Observation and documentation of caisson and tie-back drilling and installation.
• Observation of lagging placement and lower in-filling of voids at tie-back pockets.
• Observation of design sub-drain construction.
• Observation of removals and preparation of area behind wall for gravel and soil cap
backfill placement.
• Attendance at pre-grade, planning, and other construction or permit associated meetings.
• Periodic observation and documentation of field activities by our Senior Soil Technician
and Senior Engineering Geologist.
• Engineering and geology services and in-construction analyses of field and laboratory
data during construction.
• Preparation of this report and associated graphics presenting the construction conditions,
and field and laboratory test results compiled during wall construction.
Tasks Monitored by Testing Engineers:
• Observation and testing of fill placement and compaction for wall backfill, and
observation and testing of backfilling within stmm drain and connecting structure
excavations.
• Laboratory testing of representative samples for Maximum Density, gradation testing,
and sand equivalent.
Subject retaining structure construction, fill placement, and drain construction activities
commenced in October of 2005 and were completed in April of 2006. Work performed to
achieve the design was completed as reported herein.
July 7, 2006
CONSTRUCTION OBSERVATION AND FIELD TESTING
Caisson Construction
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Prior to drilling caissons, Erreca's Construction made minor cuts to produce a working pad along
the length of the proposed construction. Design plans called for construction of 34 caissons in a
single row approximately 260 feet in length, referenced from east to west as Numbers 1 through
34. Due to field considerations, Caisson Number 1, the easternmost caisson, was deleted from
the design after the beginning of construction. The caissons installed are numbered on Figure 2
as Numbers 2 through 34, east to west, respectively. On October 20, 2005, prior to the
commencement of construction, a bucket-auger drill rig was employed to pre-drill two caisson
holes (Numbers 4 and 6). The borings were extended short of design depths, but deep enough to
observe that depths of seepage and potential caving were as expected from the exploratory
borings previously completed.
Caisson excavation, reinforcement, and concrete placement operations were conducted between
October 20 and November 7, 2005. A crane-mounted drill rig using a 36-inch diameter helical
auger bit was utilized to excavate all caissons. Drilling methods and equipment employed
resulted in caisson excavations with a minimum diameter of 3-feet and a minimum depth of 26.5
feet below design grade. Caving and seepage commonly occurred in the exposed caisson walls
at depths generally less than 10 feet. Excessive caving and seepage were noted during drilling of
Caisson Numbers 16 through 19.
A structural concrete mix was to be used to fill the excavations to within a maximum of 9 feet
below design finished grade. Immediately after this placement, slurry was used to fill the
remainder of the shafts to current grade. The results of caisson excavations are incorporated into
Table 1, Caisson Data Sheet.
The bedrock in which the caissons are founded is Eocene age marine deposits assigned to the Del
Mar Formation. The bedrock consisted locally of yellow sandstone and reddish and minor green
silty claystone to clayey siltstone, interbedded at depth with medium-gray, medium to coarse-
grained sandstone. The bedrock is overlain by fill and landslide deposits. (Reference 1 ).
Tie-Back Installation
A tie-back anchor system was installed at grade through pockets welded into the sides of the
caissons. Stoney-Miller Consultants provided observation services during drilling, installation,
and testing of the anchors, in order to assess that construction was completed in accordance with
design criteria, to assess performance at both test and design loads, and to detern1ine whether
creep deformations were within specified limits. The anchor installation and testing was
conducted by Zamborelli Enterprises, Inc., between the dates of November 17, 2005 and
February 2, 2006.
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The production anchors were installed at locations indicated on the attached Site Plan, Figure 2.
The installations were conducted in general accordance with the design plans. Due to the small
size of the welded tie-back pocket on the steel H-Beams, relative to the augers on the drill rig,
shafts were drilled with offsets to the H-beams from approximately 10-inches to 4-inches. Each
tie-back shaft was drilled with an approximate 30 degree inclination below horizontal and
generally perpendicular to the face of the wall. Shafts were drilled to depths of at least 75 feet,
and 8-strand, 80 feet long tendons were installed with a maximum of 5 feet extending outside the
face of wall. The bond zone of the tie-backs was 35 feet in length for all tie-backs installed. The
drilling and grout backfilling activities operations were observed by our field personnel in order
to assess that design lengths were achieved and the grout was installed in general accordance
with the design specifications.
During the course of drilling, Tie-Back Number 28 was encountered while drilling Tie-Back
Number 27. Some disruption could have been caused by this event. Post-grouting of these
anchors was performed to mitigate future corrosion and loss of strength. Additionally, Tie-Back
Numbers 18 and 19 had to be redrilled with casing due to excessive caving and sloughing in the
shafts, which also occurred during the caisson drilling at the same locations.
Once all tie-backs were installed and grouted, high-pressure post-grouting was performed for
each tie-back utilizing a high-pressure pump and a pressure gauge. Pressures observed during
the post-grouting procedures were generally within the limits specified by the Post Tensioning
Institute's manual, Recommendations for Prestressed Rock and Soil Anchors, 1996 edition.
Tie-Back Testing and Results
General
A total of 33 tie-back anchors were installed across the toe of the La Costa De Marbella
Landslide under the observation of Stoney-Miller Consultants. The stressing of the tie-back
anchors was performed in general accordance with the design plans and criteria set forth in the
Post-Tensioning Institute's manual, Recommendations for Prestressed Rock and Soil Anchors,
1996 edition.
A design load of 250 kips was assigned to each tie-back in the structural design. Upon
completion of the caisson installation, it was determined that the Tie-back design load could be
lowered. This was due to the caissons being installed in 36-inch shafts, as opposed to 30-inch
shafts in the design, and the incorporation of larger H-Beams than called for in the design. The
larger dimensions allowed for a lower contribution of the tie-backs. Slope stability calculations
were completed which incorporated the caissons' contribution to the resisting forces against
failure. It was determined that a factor of safety of l.5 could be achieved by tensioning all of the
tie-hacks to 190 kips.
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The locations of the tie-backs are shown on Figure 2, and the results are summarized in Table 2,
Tie-Back Data Sheet. Performance testing was completed on Tie-Backs 4 and 22. In addition,
one extended creep test was performed on Tie-Back 26. The remainders of the tie-back anchors
were proof-tested to l .33x design load.
Upon completion of the testing, the protruding lengths of strands were cut and the heads were
abandoned by backfilling with grout.
Testing Procedure
The procedure for the tie-back anchor testing was accomplished in general accordance with the
guidelines given in the design plans, and in accordance with the load intervals and durations
specified therein. Equipment used to perfonn the testing included a 300-ton ram, and electric
pump, a minimum 10,000 psi pressure gauge, and a 5-inch dial gauge with a precision of 0.001
inch. Additionally, beam deflection was recorded with a 2-inch dial gauge with a precision of
0.001 inch. The gauge was positioned just above the tie-back base plates and mounted on a
stand driven into the ground. The specific model and serial numbers for the rams, pumps and
pressure gauges used during the testing are provided along with the calibration curves in
Appendix C.
Wall Backfill
The south side of the caisson retaining wall was backfilled with coarse to fine grained materials.
The lower two to three feet of the wall was generally in, or against the cut of the native material.
Where tie-back and caisson construction created voids, the voids were filled with native material
and compacted with hand equipment. Prior to placement of gravel backfill, the remainder of the
area behind the wall was prepared to receive the additional fill. The majority of the organics
were stripped from the surface for an average of about 10 feet from the back face of the wall.
Additionally, areas of negative fall were smoothed and narrow areas were widened to provide the
wall for at least IO-inches wide gravel drainage zone. The wall was backfilled with at least 10
cubic foot of gravel per lineal foot of wall. The gravel was encased in Mirafi 140 filter fabric.
The coarse wall backfill was capped along the entire length with at least a 2-foot thick layer of
fine wall backfill. Fine wall backfill material consisted of non-organic, clayey sand to sandy
clay with silt, with an Expansion Index of 90 or less. All fine wall backfill was placed in 8-inch
thick loose lifts, moistened to above optimum moisture content, and compacted. Based on
Testing Engineers observation and testing, fill soil was placed at a minimum relative compaction
of 90 percent (ASTM D 1557). Compaction was achieved using a walk-behind-double-drum
sheepsfoot roller over the majority of the area behind the wall, and a whacker in tight corners and
edges around the H-Beams and lagging. Laboratory and field testing results are summarized in
Appendix B. Approximate locations of field density tests are shown on Figure 2.
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Testing Engineers' representatives provided observation and testing services under their
jurisdiction for placement of asphalt, base, and concrete involved in road re-construction above
sub-grade. SMC services were limited to preparation of sub-grade within the access road.
During all other earthwork activities conducted within the easement, Testing Engineers'
representatives performed periodic density/laboratory testing and construction monitoring
services. A summary of field density test data by Testing Engineers are included in Appendix B
of this report.
Density tests were reported to have been performed in accordance with ASTM: D2922 and
ASTM: D3017 (Nuclear Gauge Method).
Drain Construction
Subdrains
Subgrade removals were made in the south side of La Costa A venue (LCA) right-of-way
extending to the face of the caisson wall. The sub grade was removed to a maximum depth of 3
feet below finished grade and covered with approximately 6-inches of gravel. The base of the
removal was observed and probed by the Project Geologist for competency. Prior to fill
placement in the right-of-way of La Costa A venue, a subdrain was constructed on the north side
of the caisson retaining wall (refer to Figure 2). The subdrain consisted of a 4-inch diameter
perforated, Schedule 40, PVC pipe sloped to drain from east to west at a gradient of at least 1
percent. The subdrain pipe was elevated to 6-inches above the bottom of the excavation and
surrounded by at least 3 cubic feet of gravel per lineal feet of pipe, and wrapped in filter fabric.
The subdrain transitioned to a solid 4-inch diameter PVC pipe beyond the west end of the repair
area. This solid pipe was extended to outlet into a storm drain catch located to the west of the
repair in La Costa A venue. This subdrain replaces the recommended back drain noted in our
geotechnical reports dated March 11, 2005 and June 14, 2005.
Backdrains
No back-drains were installed as part of the subject grading. Drain rock wrapped in filter fabric
was placed behind the wall to facilitate east to west drainage and to decrease the development of
excess pore water pressure behind the wall. Additionally, as fall is to the west, a 4-inch capped
perforated pipe was installed into the lower area of the gravel backfill at the west end. This pipe
is further connected to a solid pipe which outlets through and into the western terminus of the
brow ditch outlet.
Surface Drainage
Surface drainage across the slope is designed to catch in a newly constructed concrete brow-
ditch, roughly from 1 to 2 feet from the edge of the existing natural slope, running atop the soil
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cap backfill. The brow ditch is approximately 2.5 feet wide by 1.5 feet deep with fall and
drainage primarily to the west. The brow ditch outlets to collectors at the east and west ends of
the wall by a steep decline from 3 to 5 feet from the edges of the retaining structure.
Additionally, an existing concrete V-ditch, in need of repair, runs along the natural slope on the
western half. This v-ditch outlets to a riser that is tied into the collector placed near the center,
and behind, the retaining structure.
CONCLUSIONS AND RECOMMENDATIONS
General
Based on the results of our observations and testing, it is our opinion that the soldier pile caisson
and tie-back retaining system, limited to the criteria specified under our purview herein, was
completed in general accordance with our geotechnical recommendations, design plans, and
applicable grading codes. Similarly the completed toe subdrain is considered suitable for the
intended use.
Geotechnical Issues Summary
A summary of the geotechnical issues related to development of the site are presented as follows:
• Slope Stability:
As a result of the earthwork documented herein, the retaining structure should possess
gross stability for static and pseudostatic conditions. Slope maintenance guidelines
should be followed as provided in later sections of this report. Protection of slopes using
man-made materials ( e.g., jute mat, plastic membranes) may be required during the rainy
season if slopes are not well-vegetated.
• Landslides:
Based on our observations during grading, portions of the site are underlain by Landslide
deposits and fill. Future grading in these areas should be limited and closely reviewed by
the geotechnical consultant as the landslide stability and wall pressures will be affected
by any grade change. The tie-back anchor system used to stabilize the landslide is
covered with engineered fill, gravel, and native deposits. Therefore, we recommend that
the as built civil engineering plans include a WARNING or CAUTION regarding
excavating in the vicinity of the tie-backs with respect to the buried improvements.
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• Slope Deformation:
After grading, the slope south of the retaining wall should be expected to undergo some
differential vertical heave or settlement in combination with differential lateral movement
in the out-of-slope direction. This movement will likely impact all existing and future
improvements located in, and adjacent to, the existing landslide mass.
• Corrosive Soil:
Earth materials similar to those encountered on the site have a moderate to very severe
corrosive potential for at-or below grade concrete and metal elements. Mitigation
measures should be considered for any future improvements including specifying
concrete resistant to water soluble sulfates and providing corrosive protection to metal
elements or substituting non-corrosive materials in place of metal elements.
Slope Maintenance Guidelines
1. Drainage Devices
2.
Graded berms, swales, area drains, and slopes are designed to control surface water from
pad areas and should not be blocked or destroyed. Water should not be allowed to pond
in pad areas, or overtop and flow down graded or natural slopes faces.
Sources of uncontrolled water, such as leaky water pipes or drains, should be repaired.
Devices constructed to drain and protect slopes, including brow ditches, berms, and down
drains should be maintained regularly, and in particular, should not be allowed to clog
such that water can flow unchecked over slope faces. Drain outlets located at the base of
slopes and retaining walls are important for adequate long-term performance, and should
not be blocked or filled over.
In no case, should water be allowed to flow to or on a slope face in an uncontrolled
manner.
Slopes
Slopes in the southern California area should be planted with appropriate drought-
resistant vegetation as recommended by a landscape architect. Slopes should not be over-
irrigated. Heavy ground cover combined with overwatering is a primary source of
surficial slope failures .
Animal burrows can serve to collect normal sheet flow on slopes and cause rapid and
destructive erosion, and should be controlled or eliminated. Modification to slopes,
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including placement of any fill material, or excavations that steepen or otherwise modify
designed slope angles should not be attempted without direction or approval of the
geotechnical engineer.
LIMITATIONS
Our description of constrnction operations, as well as observation and testing services, has been
limited to those operations performed on the subject site under our observation and testing ending
in April of 2006. Our firm was not responsible for line and grade. Elevations and locations used
in this report are estimated based on field surveys done by others. This report should be considered
subject to review by the controlling authorities.
The opinions rendered apply to conditions in the subject areas observed and tested by us, as of the
date of our final site visit. We are not responsible for any changes in the conditions that may occur
after that date and which are outside our purview. Our testing and observation was performed in
order to render an opinion concerning retaining wall constrnction and placement of fill soil. This is
not a warranty that all fill soil was placed at or above the required relative compaction. Any future
onsite constrnction or fill placement should only be performed with the advice and
recommendations of a Geotechnical Engineer and an Engineering Geologist.
Our work is considered to be in accordance with the usual standards of the profession and with
local practice. No other warranty is expressed or implied.
July 7, 2006 Project No: 12567-10
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The opportunity to be of service is appreciated. If you have any questions, please call.
Respectfully submitted,
STONEY-MILLER CONSULTANTS, INC.
Everett C. Tabor, E.G. 2237
Engineering Geologist
Registration Expires 7-31-06
~l -~1......1"3/·u<---"I
Engin~/ri~g Geologist
Registration Expires 5-31-08
ECT /RCL/G FS/rm
Distribution: City of Carlsbad (6)
Date Signed: 71 {'~I D(,
Attachments: Figure 1, Regional Geologic/Topographic Site Location Map
Figure 2, Plan Map of Retaining Structure Improvements
Table 1, Caisson Data Sheet
Table 2, Tie-Back Data Sheet
List of Appendices: Appendix A, References
Appendix B, Backfill Testing and Observation (Testing Engineers)
Appendix C, Ram, Gauge and Pump Calibration Sheets
TABLE 1 -Caisson Data Sheet
Seepage
Max. Est. Observed
Caisson Height Total Total Shaft Seepage Seepage Rate
Number Above Depth Depth Below from Design (est.) Remarks
Design Design Grade Curb Grade Grade (ft.)
1 Omitted from design ---------1--------------------------------------------------------
2 0.5 27.5 7 Moderate
3 1 27.6
4 2 28 26 6.5 Moderate
5 27.5 4 Very Slow
6 3 29.5 26.5 Estimated Depth~4 feet--Had been predrilled with Auger left in hole.
7 Estimated depth ~ 2.5 feet.
8 3 29 26
9 28.5
10 4 30 26
11 4 31 27 and 16•, 25• I 2 Backfilled Monitoring Wells adjacent to Hole.
12 4.5 31.5 27 I
13 Clay against sidewalls-unaible to log or determine seepage.
14 4 31 .5 27.5
15 4.5 31 26.5 4.5 I
16 4.5 30.5 26 3 Slow and Moderate
17 4.5 31 26.5 3.5 and 5.5 Moderate and Rapid Seepage and Extensive Caving.
18 2.5 29 26.5 1.5and 13* Rapid I 'Caving and deep seep due to adjacent Monitoring Well backfill.
19 4 31 27 1.5, 4*, and 9.5* Slow and Moderate 1 Caving and deep seep possible due to drain and adjacent Well
20 5 32.5 27.5 1 Moderate to Rapid •I
21 1.5 31 26.5 +1 and 8 Moderate and Slow
22 4 31 27 1 Moderate Standing Water after caisson poured.
23 3.5 30 26.5 0-1 .0 Moderate Standing Water after caisson poured.
24 3.5 31 27.5
25 3 29 26 13* Slow Caving and deep seep due to adjacent Mon. Well backfill
26 2 29 27 1.5 Slow
27 1.5 28.5 27
28 1.5 30 28.5
29 1 27.5 26.5
30 0.5 27 26.5
31 0.5 27.5 27
32 0.5 27 26.5
33 0.5 27 26.5
34 0 26.2 26.2
Note: All Caisson Steel 35 feet long, with generally 26 feet below finished grade and 9 feet above finished grade (design curb grade). All shafts drilled with
a minimum 36-inch diameter. Steel H-Beam: 27" by 10".
12567-00
La Costa/Marbella Landslide
Carlsbad, CA
SMC
7/6/2006
TABLE 2 -Tieback Data Sheet
Testing I Tensioning Elongation Post Grout
Test Type Lock Max. Total Est.
Tieback P=Proof Test Off Measured Max. Beam Estimated Peak Average Number
Number Pe=Performanc Load Load Strand Deflection Elongation Water Grout of Sacks Remarks
e EC+Extended (kips) (kips) Elongation (in.) at T.L. Pressure Pressure Creep (in.) (in.)
1 Omitted from d~ri_ ---------2 p 207 190 1.998 1.2 3.198 560 520 3 End of line. Braced differently than other tieback/caissons on wall. ---3 p 250 187 2.315 1.825 4.14 300 460 5 --->------·-----
4 Pe 250 193 3.058 1.746 4.804 300 500 5 -------5 p 250 193 2.636 1.209 3.845 500 480 5
6 p 250 200 3.235 1.649 4.884 360 380 6 ---7 p 250 207 3.296 1.368 4.664 420 500 3 ,._ --· --8 p 250 207 2.776 1.348 4.124 500 480 3 ------9 p 250 200 2.734 1.257 3.991 560 480 3 ---,____
10 p 250 193 2.868 1.145 4.013 300 380 6
11 p 250 207 2.522 0.865 3.387 400 480 5 --------12 p 250 214 2.478 1.46 3.938 480 460,540 5 -·-------. 13 p 250 200 3.103 0.601 3.704 380 420 6 ---14 p 250 220 2.738 0.84 3.578 420 420 6 --
15 p 250 207 3.035 1.278 4.313 500 440 6
16 p 250 190* 2.25 NA N.A. 480 360 6 Strands Pulled seperately with C..<!__uplers. 1st pull checked for lift-off P. ------->-17 p 250 207 2.74 1.665 4.405 400 360 6 ----18 p 190 187 N.A. N.A. N.A. 480 560 3 Redrilled. 5-6 more bags in shaft. Test altered due to open space.:__ ------19 p 190 200 2.942 N.A. N.A. 700 450 3 Not full 10 min. hold. Test short-no lagging at 18 -19. --20 p 250 207 3.19 1.5 4.69 220 360 6
21 p 250 207 2.710 0.309 3.019 400 420 6 Apparent debond. Retested with Lift Off. -----~ -22 Pe 250 200 3.3 1.23 4.53 300 300 6 ----------23 p 250 200 2.862 0.908 3.77 100 150 6 -·--24 p 250 207 2.82 1.288 4.108 260 280 6 ---·--
25 p 250 200 1.96 0.85 2.81 240 360 6
26 E.C. 250 207 2.532 0.642 3.174 200 360 6 >-------27 p 250 193 2.344 0.478 2.822 300 380 6 Shaft intersected placed tieback # 28. ----28 p 250 200 2.584 1 3.584 200 300 9 Damaged Corrosion Protection/Strands Likely. (Se~ Abov~ -29 p 250 207 2.25 0.631 2.881 450 480 3 ----30 p 250 207 2.3 0.753 3.053 300 360 6 First Test: Failed Wied at base Plate, 2" + Caisson Deflection.
31 p 250 207 2.705 0.97 3.675 350 300 6 ----32 p 250 200 2.466 1.445 3.911 400 400 3 ---33 p 250 200 3 1.65 4.65 350 300 7 Gauge slipped from stand-not sure of Total Elngation. ------34 p 250 220 1.65 0.924 2.574 450 400 -9 Total Previously Post Grouted.
Notes: (1) Test Type: P=Proof, Pe=Performance, EC=Extended Creep.
12567-00
La Costa/Marbella Landslide
Carlsbad, CA
SMC
7/6/2006
APPENDIX A
REFERENCES
APPENDIX A
REFERENCES
1. Stoney-Miller Consultants, Inc., 2005, "Gcotcchnical Investigation, The La Costa De
Marbella Landslide, La Costa Avenue, City of Carlsbad, California," dated March 11,
2005, Project No: 12567-00, Report No: 05-9854.
2. Stoney-Miller Consultants, Inc., 2005, Memorandum -"Summary of Geotechnical
Design Criteria, Landslide Retaining Structure and Earthen Gravity Fill for La Costa
Avenue," La Costa De Marbella Landslide, City of Carlsbad, California, dated June 14,
2005, Project No: 12567-00, Report No: 05-9904.
PLANS
A. RBF Consulting, Inc., "Slope Repair -La Costa A venue, Rain Improvements and Stream
Stabilization Plans," undated, 40-scale Grading Plan Improvement Sheets 1 through 3.
B. Burnett and Young, Inc., 2005, "Permanent Retaining Structures, Sketches and Specs,"
La Costa De Marbella Landslide, Carlsbad, California, dated June 9, 2005, BYI File No:
05-0515.
APPENDIX B
BACKFILL TESTING AND OBS ERV A TCON
(Testing Engineers)
SAMPLE#
2
3
4
5
TABLE I
RESl!L TS OF MAXIMlll\1 DENSITY TEST
(ASTM-D-1557)
DESCRIPTION
Import: Rock Hase
Import: Rock Base
On-site:fmport: Olive/tan Silty Clayey SAND
On-site• Import: Tan Clayey SAND w1 (iravel
Import: Asphaltic Concrete
MAXIMUM DRY
DENSITY (PCF)
140.0
142.5
124.0
123.0
150.0
OPTIMUM MOISTURE
CONTENT(%)
6.5
6.5
IU
10.5
Contract Number:
Project Name:
Location:
Test Sample Test
# #
Date
1 1 2/17/2006
2 2 2/17/2006
3 2 2/21/2006
4 2 2/21/2006
5 3 3/9/2006
6 3 3/9/2006
7 3 3/9/2006
8 3 3/15/2006
9 3 3/15/2006
10 3 3/16/2006
11 3 3/16/2006
12 3 3/17/2006
13 4 3/17/2006
14 3 3/20/2006
15 2 3/23/2006
16 2 3/23/2006
17 2 4/3/2006
18 2 4/3/2006
TABLE2
REPORT OF COMP ACTION TEST DATA
114152
Marbella Slope Stabilization
La Costa Ave. and Marbella
Carlsbad. CA
Test Location
La Costa E bound 1 0' from retaining wall,
Sta 3+00. 1' below BG
La Costa E bound 1 0' from retaining wall.
Sta 5+00. 1' below BG
SD Trench backfill. Sta 1 +00
SD Trench backfill. Sta 1 +00
La Costa caisson retaining wall Sta 2+80.
4' below TVV
La Costa caisson retaining wall Sta 3+80.
4' below TVV
La Costa caisson retaining wall Sta 3+00.
4' below TVV
La Costa caisson retaining wall Sta 3+50.
1' below TVV
La Costa caisson retaining wall Sta 3+00,
1' below TVV
La Costa caisson retaining wall Sta 5+00.
2' below TVV
La Costa caisson retaining wall Sta 4+00.
2' below TVV
La Costa caisson retaining wall Sta 4+50.
2' below TVV
La Costa caisson retaining wall Sta 4+25.
1' below TVV
La Costa caisson retaining wall Sta 3+25.
1' below TVV
La Costa CG Sta 3+00. at BG
La Costa CG Sta 3+00, at BG
La Costa caisson wall at 4.5' below TVV
La Costa caisson wall. 7' S of south wall
face. at 2.5' below TVV
Moisture
Field I Optimum
8.3% 6.5%
7.5% 6.5%
8.3% 6.5%
9.1% 6.5%
11.1% 11.5%
10.3% 11.5%
13.2% 11.5%
14.0% 11.5%
14.2% 11.5%
13.6% 11.5%
14.0% 11.5%
12.7% 11 .5%
11.5% 10.5%
13.2% 11.5%
8.3% 6.5%
8.7% 6.5%
8.3% 6.5%
7.5% 6.5%
Dry Density (pcf)
Field I Maximum
135.9 140.0
136.7 142.5
135.7 142.5
136.3 142.5
112.2 124.0
111.5 124.0
113.5 124.0
112.9 124.0
120.8 124.0
114.6 124.0
114.1 124.0
133.3 124.0
122.2 123.0
112.8 124.0
137.1 142.5
137.0 142.5
131.0 142.5
131.3 142.5
Relative Compaction Conform
Obtained I Required Non-Conform
97% 95% Conform
96% 95% Conform
95% 95% Conform
96% 95% Conform
90% 90% Conform
90% 90% Conform
92% 90% Conform
91% 90% Conform
97% 90% Conform
92% 90% Conform
92% 90% Conform
108% 90% Conform
99% 90% Conform
91% 90% Conform
96% 95% Conform
96% 95% Conform
92% 90% Conform
92% 90% Conform
Contract Number:
Project Name:
Location:
Test Sample Test
# #
Date
19 2 4/11/2006
20 2 4/11/2006
21 2 4/11/2006
22 AC 4/12/2006
23 AC 4/12/2006
24 AC 4/12/2006
25 AC 4/12/2006
26 AC 4/12/2006
27 AC 4/12/2006
28 AC 4/12/2006
29 AC 4/12/2006
30 AC 4/12/2006
31 AC 4/12/2006
32 3 4/25/2006
33 3 4/26/2006
34 2 5/9/2006
35 2 5/9/2006
36 AC 5/9/2006
37 AC 5/9/2006
38 AC 5/9/2006
39 AC 5/9/2006
40 AC 5/10/2006
41 AC 5/10/2006
42 AC 5/10/2006
43 AC 5/10/2006
44 AC 5/10/2006
TABLE2
REPORT OF COMPACTION TEST DATA
114152
Marbella Slope Stabilization
La Costa Ave. and Marbella
Carlsbad. CA
Test Location
La Costa Sta 4+50. 1 0' N of RT, at BG
La Costa Sta 3+00. 1 0' N of RT. at BG
La Costa Sta 1 +50. 1 0' N of RT, at BG
3' from curbline at Sta 0+05
3' from curbline at Sta 0+77
3' from curbline at Sta 1+02
3' from curbline at Sta 1 +27
3' from curbline at Sta 1+55
5' from curbline at Sta 2+65
6' from FC at Sta 3+10
9' from FC at Sta 4+50
6' from FC at Sta 4+50
3' from FC at Sta 5+00
18" SD bf Sta 10+55
18'' SD bf Sta 10+20
La Costa Ave SD Sta 10+20
La Costa Ave SD Sta 10+50
La Costa Ave SD Sta 10+20
La Costa Ave SD Sta 10+20
La Costa Ave SD Sta 10+50
La Costa Ave SD Sta 10+50
La Costa Ave, 1.5" Grind and Pave. Sta
31+00.6'FC
La Costa Ave. 1.5" Grind and Pave. Sta
31+75.8' FC
La Costa Ave. 1.5" Grind and Pave, Sta
32+50. 8'FC
La Costa Ave. 1.5" Grind and Pave. Sta
33+25,6'FC
La Costa Ave. 1.5" Grind and Pave. Sta
34+00,6'FC
Moisture
Field I Optimum
8.3% 6.5%
7.5% 6.5%
7.1% 6.5%
11.9% 11.5%
12.4% 11.5%
7.0% 6.5%
7.1% 6.5%
Dry Density (pcf)
Field I Maximum
136.6 142.5
139.4 142.5
137.8 142.5
140.0 150.0
139.6 150.0
142.3 150.0
145.3 150.0
145.6 150.0
144.9 150.0
141.4 150.0
146.1 150.0
140.8 150.0
143.6 150.0
119.4 124.0
119.1 124.0
136.4 142.5
136.1 142.5
149.4 150.0
148.6 150.0
147.5 150.0
147.9 150.0
147.5 150.0
142.6 150.0
146.6 150.0
147.1 150.0
146.4 150.0
Relative Compaction Conform
Obtained I Required Non-Conform
96% 90% Conform
98% 90% Conform
97% 90% Conform
93% 95% Nonconform
93% 95% Non conform
95% 95% Conform
97% 95% Conform
97% 95% Conform
97% 95% Conform
94% 95% Non conform
97% 95% Conform
94% 95% Nonconform
96% 95% Conform
96% 95% Conform
96% 95% Conform
96% 95% Conform
96% 95% Conform
100% 95% Conform
99% 95% Conform
98% 95% Conform
99% 95% Conform
98% 95% Conform
95% 95% Conform
98% 95% Conform
98% 95% Conform
98% 95% Conform
Contract Number:
Project Name:
Location:
Test Sample Test
# #
Date
45 AC 5/10/2006
46 AC 5/10/2006
47 AC 5/10/2006
48 AC 5/10/2006
49 AC 5!10/2006
50 AC 5/10/2006
51 AC 5/10/2006
52 AC 5/10/2006
53 AC 5/10/2006
TABLE2
REPORT OF COMPACTION TEST DATA
114152
Marbella Slope Stabilization
La Costa Ave. and Marbella
Carlsbad. CA
Test Location
La Costa Ave. 1 .5" Grind and Pave. Sta
34+75, 6' FC
La Costa Ave. 1.5" Grind and Pave. Sta
35+50. 6' FC
La Costa Ave. 1.5" Grind and Pave. Sta
32+50. 18' FC
La Costa Ave. 1.5" Grind and Pave. Sta
33+25. 18' FC
La Costa Ave. 1.5" Grind and Pave. Sta
34+00. 18' FC
La Costa Ave. 1.5" Grind and Pave. Sta
34+75. 18' FC
La Costa Ave. 1.5" Grind and Pave. Sta
34+50. 18' FC
La Costa Ave. 1.5" Grind and Pave. Sta
10+20 SD
La Costa Ave. 1.5" Grind and Pave. Sta
10+40 SD
Moisture
Field I Optimum
Dry Density (pcf)
Field I Maximum
145.4 150.0
142.9 150.0
145.3 150.0
144.7 150.0
142.9 150.0
143.4 150.0
145.0 150.0
144.8 150.0
146.4 150.0
Relative Compaction Conform
Obtained I Required Non-Confonn
97% 95% Conform
95% 95% Conform
97% 95% Conform
96% 95% Conform
95% 95% Conform
96% 90% Conform
97% 90% Conform
97% 90% Conform
98% 90% Conform
APPE DIX C
RAM, GAUGE A D PUMP CALIBRATIO SHEETS