HomeMy WebLinkAbout3557; Carlsbad Blvd Phase II Bridge; Carlsbad Blvd Phase II Bridge; 2002-06-21City of Carlsbad
In Cooperation with the
California Department of Transportation
Local Agency Seismic Retrofit Program
Carlsbad Boulevard Overhead
Bridge No. 57C-0134
Seismic Assessment and Retrofit Strategy Report
Prepared by
Simon Wong Engineering
9968 Hibert Street, Suite 202
San Diego, CA 92131
Revised June 21, 2002
TABLE OF CONTENTS
I. ABSTRACT 1
II. PROJECT DESCRIPTION 2
III. BRIDGE DESCRIPTION 2
IV. GEOLOGICAL CONDITIONS 3
V. ASSESSMENT CRITERIA 3
VI. AS-BUILT ANALYSIS RESULTS 4
VII. RETROFIT STRATEGY 5
Vll. PRELIMINARY COST ESTIMATES 6
IX. PROJECT TEAM 6
X. REFERENCES 7
APPENDICES
Appendix A GENERAL PLAN A-1
Appendix B DEMAND CAPACITY SUMMARY B-1
Appendix C PRELIMINARY COST ESTIMATE WORKSHEET C-1
Appendix D PRELIMINARY GEOTECHNICAL RECOMMENDATIONS D-1
Appendix E SHEAR WALL VS. SUPERBENT CALCULATIONS E-1
Appendix F CRASH WALL REMOVAL CALCULATIONS F-1
Local Agency Seismic Retrofit Program
Carlsbad Boulevard Overhead
Simon Wong Engineering
SWE Job#500-I76
Rev. June 21, 2002
ABSTRACT
Project Identification Bridge Name:
Bridge Number:
Location:
Year Constmcted:
Carlsbad Boulevard Overhead
57C-0134
City of Carlsbad
1925
Structure Description
The existing 165 ft. long five-span bridge consists of simply supported reinforced concrete
T-beam spans founded on concrete piers and abutments with spread footings. This bridge
was constmcted in 1925 and subsequently widened in 1936. Concrete cap beams, which are
supported on 5 - 2.0 ft. square columns, make up each bent. Bents 2 through 5 are founded
on continuous 4.0 ft. wide spread footings with a collision wall (1.0 ft. thick reinforced
concrete infill wall), which extends up approximately 12.0 ft. from the footing. The columns
at Abutments 1 and 6 are supported on individual 5.0 ft. square spread footings. All Bents
are skewed 45°.
Assessment Criteria
Depth of Alluvium = 7 to 15 ft.
Horizontal Bedrock Acceleration 0.45g
Concrete Compressive Strength = 4,500 psi
Reinforcing Steel Yield Stress = 36,000 psi
As-Built Analysis and Structure Response
The existing stmcture was analyzed using both the equivalent static and response spectra
methods to determine the displacement demands and inelastic static analysis to determine
the capacity. The bent and abutment spring constants were adjusted according to Caltrans
guidelines using cracked section properties.
Column plastic shear demands exceed the capacity at all bents for at least one ofthe three
criteria used to evaluate shear capacity. Column shear capacities are exceeded in Abutments
1 and 6 for all criteria evaluated. Cap beams are insufficiently reinforced to resist reversing
column plastic moments. Seat width is insufficient for the expansion supports at Bents 3 and
4.
Retrofit Strategy
The proposed retrofit strategy features a superbent encasement of Bents 2 and 5. This
superbent will be approximately 3.0 ft. thick with a widened footing and bentcap. Shear keys
at the bentcap and concrete bolsters will be used at Bents 2 and 5. Seat extenders and
recompaction of the fill will be required at Abutments 1 and 6. The increased stifftiess and
strength of this superbent will reduce displacements on the adjacent bents and resist nearly
all ofthe seismic forces during a design level event.
Simon Wong Engineering
Local Agency Seismic Retrofit Program SWE Job# 500-176
Carlsbad Boulevard Overhead Rev. June 21, 2002
II. PROJECT DESCRIPTION
A seismic assessment strategy was performed by Moffat and Nichol Engineers as part of the
Caltrans Local Agency Seismic Retrofit Program. Their findings were summarized in the
As-built Assessment and Strategy Report dated March 11, 1997.[1] The results of their
assessment indicated inadequate column ductility capacity and insufficient seat width. As a
consequence, a retrofit consisting of full-height infill walls at Bents 2 through 5 and concrete
bolster seat extensions for all cap beams was recommended. The preliminary cost estimate
by Moffat and Nichol Engineers for the retrofit was $355,000 and has been included in
Appendix C.
This strategy was accepted by Caltrans. However, the North County Transit District (NCTD)
reviewed this strategy and concluded that it was unacceptable as the retrofit encroached
within allowable track clearances. Also, the costs ofthe retrofit as stated in the report did not
include shoring, shoofly costs and flagmen. To build this retrofit, as planned in Ref [1], the
estimated costs including these additional factors could exceed $1.7 million as shown in
Appendix C.
As a result, the City of Carlsbad with their consultants began a study to investigate the
feasibility of replacing the Carlsbad Boulevard Overhead. Due to the initial estimated project
costs, the planned replacement project was cancelled and the assessment and retrofit
investigation was continued. This report summarizes the development of a seismic
assessment and retrofit strategy that is acceptable to Caltrans, the City of Carlsbad and
NCTD.
III. BRIDGE DESCRIPTION
The bridge retrofit project is located on Carlsbad Boulevard over the North County Transit
District (NCTD) rail line. Carlsbad Boulevard is approximately 0.5 miles west of Interstate
5 through the City of Carlsbad (see 2001 edition ofthe Thomas Brothers Guide 1106-D-5).
The existing 165 ft. long five-span bridge consists of simply supported reinforced concrete
T-beam spans founded on concrete piers and abutments with spread footings. This bridge
was constmcted in 1925 and widened in 1936
Bridge Name: Carlsbad Boulevard Overhead
Width: 50.7 ft.
Height: 26.4 ft., measured from track to profile grade
Length: 165 ft.
Skew: 45°
Comments: 5 simple spans supported on concrete piers and abutments
Simon Wong Engineering
Local Agency Seismic Retrofit Program SWE Job# 500-176
Carlsbad Boulevard Overhead Rev. June 21, 2002
Superstmcture: Cast-in-place T-beam with simple supports. Expansion bearings in
Spans 2 and 4 at Bents 3 and 4, respectively.
Abutments: Concrete cap beam supported on five 2.0 ft. square columns. Each
column is supported on 5.0 ft. square spread footings.
Bents: Concrete cap beam supported on five 2.0 ft. square columns with a
continuous spread footing. Crash wall (1.0 ft. thick reinforced concrete
infill wall) extends approximately 12.0 ft. from the footing.
A field investigation of the bridge was performed on August 15, 2000. The column spacing
of the widen bridge is 12.5 ft. instead of 16.4 ft.. The backfill near both abutments is
showing signs of erosion.
IV. GEOLOGICAL CONDITIONS
Three geotechnical reports, which provide general recommendations regarding foundation
stiffness, bearing capacities and other issues regarding stmctural capacities, have been
included in Appendix D. These include the Preliminary Geotechnical Report dated May 23,
1997, the Liquefaction Report dated August 12, 1997, and the Recommended Geotechnical
Parameters dated March 5, 2001.
In the assessment, the embedded columns at abutments 1 and 6 were treated as piles. Pile
analysis (using Lpile) was used to evaluate the potential failure modes for the embedded
columns and to develop realistic soil springs for the global analysis.
Seismicity
Response Spectra Curve: ATC-32 Type D (Magnitude 7.25)
Peak Ground Acceleration (PGA): 0.45g
Maximum Spectral Acceleration: l-20g (with 5% critical damping)
No liquefaction anticipated at this site.
V. ASSESSMENT CRITERIA
Since Carlsbad Boulevard is not considered a lifeline stmcture, the seismic performance
criteria used for the assessment was to prevent collapse during a maximum credible seismic
event. Caltrans refers to this level of seismic shaking as a Safety Evaluation Event (SEE).
For further information regarding site seismicity, see the attached Geotechnical Report in
Appendix D.
Analysis
In order to capture the nonlinear effects and to determine the force and displacement
capacities of the individual bents, an inelastic static (pushover) analysis was performed
using the program wFRAME [2]. Plastic hinge rotational capacities were determined using
Local Agency Seismic Retrofit Program
Carlsbad Boulevard Overhead
Simon Wong Engineering
SWE Job# 500-176
Rev. June 21, 2002
the moment-curvature analysis program xSECTION [3]. To determine the displacement
demands of each bent, a stand-alone analysis was performed using cracked properties of
both the columns and cap beams. The concrete deck was assumed to act as a rigid
diaphragm.
To determine the demands, a response spectra analysis was performed using the dynamic
analysis program Seisab [4]. Due to the very stiff conditions of the bridge in the transverse
direction (parallel to the centeriine ofthe bent) the analysis reported relatively small
displacements, and the predominant mode of displacement was transverse to the bent
centeriine. In this direction, rocking response was anticipated for bents 2 through 5.
Rocking demands were estimated using an iterative approach as outlined in Ref [6] and a
10% damping ratio.
Material Properties
Probable material strengths of the As-built stmcture were used to perform the assessment as
suggested in Ref [6]. These material properties differ from the design strengths due to
conservatism in the mix design, and the increase in concrete strength with time.
Assumed material strength
Item Design (psi) Probable (psi)
Concrete fc 3,000 4,500
Reinforcing fy 36,000 36,000
Steel full 58,000
0.10 in/in
VI. AS-BUILT ANALYSIS RESULTS
In general, the stmcture is tied together well with the superstmcture connected to the bents
(except for the expansion sides of Bents 3 and 4) and abutments, with the relatively stiff
piers. The stmcture is anticipated to have relatively small transverse displacements in the as-
built configuration. Longitudinally, the anticipated displacements may exceed the available
seat width at the expansion bearings of Bents 3 and 4 under rocking response. Our analysis
has shown the deficiencies with Columns, Cap Beam and Seat Width. Below are the
findings for each of these items.
Columns
Since the columns are lightly loaded, there is significant flexural ductility capacity without
any significant confinement reinforcement. For Bents 2-5, the maximum demands vs.
capacity ratios are less than 1.0 for all columns. For Abutments 1 and 6 columns, the
maximum demand vs. capacity ratio is 1.17 and 1.24 respectively, indicating potential
failure of the column plastic hinge. The column results have been summarized in Appendix
B
Simon Wong Engineering
Local Agency Seismic Retrofit Program SWE Job# 500-176
Carlsbad Boulevard Overhead Rev. June 21, 2002
The existing collision walls shorten the effective length of the columns in Bents 2 through 5.
This increases the transverse shear demands resulting from plastic hinging of the columns.
As shown, the shear capacity was calculated using three different criteria. The criteria listed
in the Caltrans Seismic Design Criteria (SDC) [5] indicates shear failure could occur in all
bent and abutment columns, whereas the criteria developed by Priestley et. al. [6] and ATC-
32 [7] indicates that shear failure could occur at Abutments 1 and 6 only.
Cap beam
The cap beams were designed primarily for gravity loads and not for the fully reversing
seismic moments acting on the stmcture. Hence, light reinforcement was provided at
seismically critical sections ofthe cap beam resulting in a moment capacity that is a fraction
of the cracking moment. Under reversing seismic moments large cracks could develop
resulting in reduced shear capacity and subsequent shear failure.
Seat Width
As discussed previously, all concrete spans are secured to the cap beams with the exception
of Span 2 to Bent 3 and Span 4 to Bent 4 where expansion bearings were provided. The seat
width of approximately 12" is not sufficient, as compared to the displacement demands at
these locations assuming out of phase movement.
VII. RETROFIT STRATEGY
The following retrofit strategy consists of three components to address the deficiencies
discussed in the previous sections. The temporary and permanent conflicts with railroad
operations were considered in the development of this strategy. The location of these
components is shown on the general plan in Appendix A.
Superbent Concrete Encasement of Bents 2 and 5
A 3.0 ft. thick concrete wall would encase the existing columns from the footing to the top
of the bent cap. The existing collision walls would be removed prior to bent encasement to
allow for the placement of cross tie reinforcement. Concrete relief consisting of pilasters
would be used to match the existing bent appearance. Encasement of the bentcap would
extend transversely beyond the existing cap to provide support for the extemal shear keys.
The footing would be widened from 4 ft. to approximately 10ft. and thickened to
approximately 4 ft. The superbent will resist nearly all of the fransverse seismic load while
reducing the longitudinal displacement demands to below the available seat width.
Restrainer Pipes and Concrete Bolsters for Bents 2 and 5
Concrete bolsters supporting restrainer pipes will be added to Bents 2 and 5. This prevents
the adjacent spans from rotating and allows for the transfer of lateral loads to the superbents.
This allows the bridge deck to respond as a rigid diaphragm during a seismic event. Since
the spans are fixed against translation in the as-built condition, expansion does not have to
be provided and both ends of the restrainer pipes are to be fixed.
Local Agency Seismic Retrofit Program
Carlsbad Boulevard Overhead
Simon Wong Engineering
SWE Job# 500-176 .
Rev. June 21, 2002
Seat Extenders and Recompaction of fill at Abutments 1 and 6
Seat extenders and recompaction of the fill under the cap beams of Abutments 1 and 6
would reduce the potential settlement ofthe abutments. Although shear failure is anticipated
in the abutment columns, the cap beams are at grade and subsequent to loss of vertical load
carrying capacity the cap beam would bear directly on fill. Seat extenders would prevent
unseating ofthe superstmcture. The recompaction could be performed by removal of
several feet of soil under the cap beam and replaced with lean concrete or sand slurry. The
erosion problems behind the abutments should also be corrected by placing lean concrete or
sand slurry where the soil has washed away from behind the abutment diaphragm.
This strategy reduces the bent displacements, as shown in Appendix B, transversely so that
shear failure will not occur in Bents 2-5. Longitudinally, the displacements are reduced to
below the available seat width for the expansion bearings. No retiofit work is required at
bents 3 and 4 adjacent to the railroad.
Other Retrofit Alternatives Evaluated
This retrofit strategy report is an update to the report performed by Moffat and Nichol
Engineers in 1997 and accepted by Caltians. This retrofit consisted of full-height infill walls
at Bents 2 through 5 and concrete bolster seat extensions for all cap beams. This retrofit was
stmcturally feasible but was considered unacceptable to NCTD.
A shear wall retrofit altemative at Bents 2 and 5 was also considered at the request of
Caltrans. The evaluation of this altemative is included in Appendix E. This altemative is
sUghtly more cost effective than the proposed strategy but has unacceptable drill and bond
dowel details.
Removal of the existing collision walls was evaluated in Appendix F. The conclusion was
that removal is more economical than encasement because he placement of cross tie
reinforcement is simplified.
VIIL PRELIMINARY COST ESTIMATES
Preliminary cost estimates for the retrofit measures discussed previously are listed in
Appendix C and amounts to $895,000, which is equivalent to $85/ft.^.
IX. PROJECT TEAM
Project Manager: Marshall Plantz City of Carlsbad (760) 602-2766
Geotechnical: Shah Ghanbari Group Delta Consultants (949) 609-1020
Project Manager: Mark Creveling Simon Wong Engineering (858) 566-3113
Project Engineer: Jim Frost Simon Wong Engineering (858)566-3113
Local Agency Seismic Retrofit Program
Carlsbad Boulevard Overhead
Simon Wong Engineering
SWE Job# 500-176
Rev. June 21, 2002
X. REFERENCES
[1] Moffat and Nichol Engineers, As-Built Assessment and Strategy Report, Santa Ana,
Califomia, June 1997.
[2] Seyed, M., wFRAME Users Manual (Draftf, Sacramento, Califomia, 1994.
[3] Seyed, M., xSECTION Users Manual (DraftJ, Sacramento, Califomia, 1994.
[4] Imbsen and Associates, SEISAB Version 4.3 Users Manual, Sacramento, Califomia,
May 1999.
[5] Caltrans, Seismic Design Criteria, Version 1.1, July 1999.
[6] Priestley, M. J. N., Seible, F. and Calvi, M., Seismic Design and Retrofit of Bridges,
John Wiley & Sons, New York, 1996.
[7] ATC-32, Improved Seismic Design Recommendations for California Bridges, Applied
Technology Council, Redwood City, Califomia, 1996.
Appendix A
GENERAL PLAN
A-1
165'-0 1/2"±
200'±VC
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ABUT 1
\"1 =1
J^iL Inn - ii - rin r - -1 r in - - -
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I ii i il i
r—tt-iri
==|H
lii _l l[l H I II ! I ^
[pfi.._..ijiiz::a^^jt^i:r
."ZIZI
11 4
BENT 2
BENT 4
BENT 3
ELEVATION
BENT 5
SLSSh SL
—1'-8"±
ABUT 6
1 = 10'
32'-0"± 30'-7"±
I
26'-10 l/2"± 30'-7"± 45'-0"±
d.-<^
1" = 10
ORIGINAL SCALE OF
FULL SIZE PLANS
(INCHES)
' I I '
1 2 REVIEWED BY:
BENCHMARK:
DESCRIPT:
LOCATION:
RECORDS:
ELEVATION:
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msa H2Mrt Stri«t Suft. 202
Son DUgo. M »213l (8M) SU-3M]
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LIGEND:
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0
0
TYPICAL SECTION
SECTION @
1/8" = I'-O"
INDICATES EXISTING STRUCTURE
INDICATES NEW CONSTRUCTION
INDICATES LOCATION OF WORK
BENT ENCASEMENT (BENTS 2 AND 5 ONLY)
DIAPHRAGM BOLSTER WITH RESTRAINER PIPE
(BENTS 2 AND 5 ONLY)
SEAT EXTENDER AND RECOMPACT SOIL
(ABUT 1 AND 6)
REVISION DESCRIPTION OTHER APPROVAL OTr APPROVAL
SHEET 1 CITY OF CARLSBAD
ENGINEERING DEPARTVIENT
SHEETS
1
BRIDGE DETAILS FOR:
CARLSBAD BOULEVARD
OVERHEAD RETROFIT
GENERAL PLAN
PREUMINARY STUDIES
NOT FOR CONSTRUCTION
DWN BY: CHKD BY:
RVWD BY:
PROJECT NO.
3557
Appendix B
DEMAND CAPACITY SUMMARY
B-1
As-Built Assessment
Demand / Capacity Results
Location
(1)
Displacement
Demand (in)
Displacement
Capacity (in)
Displacement
Die Ratio
Disp. Ductility Shear
Demand (k)
Shear
Capacity (k)
Trnv. Shear
D/C Ratio Location
(1) Trnv. (2) Long. (3) Trnv. Long. (4) Trnv. Long. (4) Trnv. Long. Trnv. Long. SDC ATC-32 Priestley Max (5) Min (6)
Abut. 1 4.40 7.8 4.1 6.68 1.07 1.17 2.9 5.1 98.4 39.6 50 62.3 66.0 1.97 1.58
Bent 2 2.50 12.2 2.9 n/a 0.85 n/a 7.1 <1 52.0 12.0 22 62.9 57.1 2.36 0.83
Bent 3 1.70 12.2 2.9 n/a 0.58 n/a 4.9 <1 55.3 12.0 22 63.8 60.3 2.51 0.87
Bent 4 1.60 12.2 2.9 n/a 0.55 n/a 4.6 <1 55.3 12.0 22 63.8 60.3 2.51 0.87
Bent 5 1.80 12.2 2.9 n/a 0.61 n/a 5.1 <1 61.0 18.0 22 65.0 64.2 2.77 0.94
Abut. 6 3.40 8.3 4.1 6.68 0.83 1.24 2.2 5.5 98.4 39.6 74 62.3 66.0 1.33 1.58
Notes:
1. Abutments 1 and 6 are simmilar except in tributary span length. Bents 2 - 5 are simmilar except for minor column height and tributary span length.
2. Transverse displacement demand based on global (Seisab) model.
3. Bent longitudinal displacement demands based on rocking response using stand-alone analysis and WinRock program.
Abutment longitudinal displacement demands based on global (Seisab) model.
4. The longitudinal capacity is not applicable since rocking occurs prior to longitudinal plastic hinging.
5. Maximum transverse shear D/C ratio using the SDC shear capacity formula.
6. Minimum transverse shear D/C ratio using the larger of the ATC-32 and the Priestly shear capacity formulas.
Simon Wong Engineering
5/14/01
Carlsbad Boulevard Overhead
Appendix B
Retrofit Assessment
Demand / Capacity Results
Location
Displacement
Demand (in)
Displacement
Capacity (in)
Displac
D/C
;ement
Ratio
Disp. Ductility Shear
Demand (k)
Sliear
Capacity
(k)
Shear
D/C
Ratio
Location
Trnv. (1) Long.(2) Trnv. Long.(3) Trnv. Long.(3) Trnv. Long. Trnv. Long.
Sliear
Capacity
(k)
Shear
D/C
Ratio
Abut. 1 0.50 7.8 4.1 6.68 0.12 1.17 0.3 5.1 82 39.6 22 3.73
Bent 2 0.30 8.2 n/a n/a n/a n/a <1 <1 1200 240 2000 0.60
Bent 3 0.30 8.2 2.9 n/a 0.10 n/a 0.9 <1 55 12 101 0.55
Bent 4 0.30 8.2 2.9 n/a 0.10 n/a 0.9 <1 55 12 101 0.55
Bent 5 0.30 8.2 . n/a n/a n/a n/a <1 <1 1200 240 2000 0.60
Abut. 6 0.70 7.7 4.1 6.68 0.17 1.15 0.5 5.1 82 39.6 22 3.73
Notes:
1. Transverse displacement demand based on global (Seisab) model.
2. Bent longitudinal displacement demands based on rocking response using stand-alone analysis and WinRock program.
Abutment longitudinal displacement demands based on global (Seisab) model.
3. The longitudinal capacity of bents 2 - 5 is not applicable since rocking occurs prior to longitudinal plastic hinging.
Simoti Wong Engineering
5/14/01
Cartsbad Boulevard Overhead
Appendix B
Appendix C
PRELIMINARY COST ESTIMATE WORKSHEETS
c-1
Preliminary Cost Estimate Worksheet
SUPERBENT RETROFIT STRATEGY
• GENERAL PLAN ESTIMATE OR PLANNING ESTIMATE
BRIDGE CARLSBAD BOULEVARD OVERHEAD BR NO 57C-0134 REC'D BY
TYPE CAST-IN-PLACE T-BEAM DIST 11 |C0 SD RTE 1
LENGTH 165 X WIDTH 50.7 =AREA 8,366 ft^
DESIGN SECTION QUANTITIES BY DATE ESTIMATE NO.
PROJECT INCLUDES QUANT. CHECKED BY DATE PRICE BY
AND $ ROADWORK CHG UNIT AND EA COST INDEX
NO. CONTRACT ITEMS UNIT QUANTITY PRICE AMOUNT
1 STRUCTURE EXCAVATION (BRIDGE) CY 680 $75.00 $51,000
2 STRUCTURE BACKFILL (BRIDGE) CY 290 $100.00 $29,000
3 STRUCTURAL CONCRETE, BRIDGE FOOTING CY 140 $350 $49,000
4 STRUCTURAL CONCRETE, BRIDGE CY 320 $800 $256,000
5 BAR REINFORCING STEEL (BRIDGE) LB 114500 $0.75 $85,875
6 DRILL AND BOND DOWEL LF 900 $45.00 $40,500
7 STRUCTURAL STEEL LB 2600 $2.00 $5,200
8 CONCRETE REMOVAL CY 35 $300.00 $10,500
9 RAILROAD FLAGGING DAY 60 $280.00 $16,800
10 DRAINAGE LS 1 $20,000.00 $20,000
11 ROADWAY EXCAVATION CY 560 $100.00 $56,000
12 NCTD REVIEW & PERMITTING LS 1 $30,000.00 $30,000
13
14
15
16
17
18
19
20
21
SUB TOTAL $649,875
MOBILIZATION 10% $64,988
SUB TOTAL - BRIDGE ITEMS $714,863
COST PER SQUARE FOOT $ 85
CONTINGENCIES @ 25% $178,716
TOTAL $893,578
FOR BUDGET PURPOSES - SAY $895,000
Note: Preliminary cost data does not include Caltrans oversite, design and construction engineering costs.
c-2
Preliminary Cost Estimate Worksheet
ORIGINAL 1997 MOFFAT AND NICHOL ENGINEERING STRATEGY
• GENERAL PLAN ESTIMATE OR PLANNING ESTIMATE
BRIDGE CARLSBAD BOULEVARD OVERHEAD BRNO 57C-0134 REC'D BY
TYPE CAST-IN-PLACE T-BEAM DIST 11 |C0 SD RTE 1
LENGTH 165 X WIDTH 50.7 = AREA 8,366 ft^
DESIGN SECTION QUANTITIES BY DATE ESTIMATE NO.
PROJECT INCLUDES QUANT, CHECKED BY DATE PRICE BY
AND $ ROADWORK CHG UNIT AND EA COST INDEX
NO. CONTRACT ITEMS UNIT QUANTITY PRICE AMOUNT
1 BRIDGE REMOVAL LS 1 $20,000.00 $20,000
2 STRUCTURAL CONCRETE, BRIDGE CY 373 $350 $130,550
3 DRILL AND BOND DOWEL LF 3866 $15.00 $57,990
4 BAR REINFORCING STEEL (BRIDGE) LB 99627 $0.60 $59,776
SUB TOTAL $268,316
MOBILIZATION 10% $26,832
SUB TOTAL - BRIDGE ITEMS $295,148
COST PER SQUARE FOOT $ 35
CONTINGENCIES @ 20% $59,030
TOTAL $354,177
FOR BUDGET PURPOSES - SAY $355,000
Note: Cost estimate as approved by Caltrans in the June 1997 As-Built Assessment and Stretegy Report.
C-3
Preliminary Cost Estimate Worksheet
MODIFIED MOFFAT AND NICHOL ENGINEERING STRATEGY
• GENERAL PLAN ESTIMATE OR PLANNING ESTIMATE
BRIDGE CARLSB/VD BOULEVARD OVERHEAD BRNO 57C-0134 REC'D BY
TYPE CAST-IN-PLACE T-BEAM DIST 11 |C0 SD RTE 1
LENGTH 165 X WIDTH 50.7 = AREA 8,366 ft'
DESIGN SECTION QUANTITIES BY DATE ESTIMATE NO.
PROJECT INCLUDES QUANT CHECKED BY DATE PRICE BY
ANDS ROADWORK CHG UNIT AND EA COST INDEX
NO. CONTRACT ITEMS UNIT QUANTITY PRICE AMOUNT
1 STRUCTURE EXCAVATION (BRIDGE) CY 150 $75.00 $11,250
2 STRUCTURE BACKFILL (BRIDGE) CY 150 $100.00 $15,000
3 STRUCTURAL CONCRETE, BRIDGE CY 373 $1,200 $447,600
4 BAR REINFORCING STEEL (BRIDGE) LB 100000 $0.75 $75,000
5 DRILL AND BOND DOWEL LF 3900 $45.00 $175,500
6 CONCRETE REMOVAL LS 1 $20,000.00 $20,000
7 RAILROAD FLAGGING DAY 60 $280.00 $16,800
8 DRAINAGE LS 1 $20,000.00 $20,000
9 GRADE EMBANKMENT SLOPES CY 560 $100.00 $56,000
10 NCTD REVIEW & PERMITTING LS 1 $30,000.00 $30,000
11 SHO-FLY LS 1 $400,000.00 $400,000
12
13
14
15
16
17
18
• 19
20
21
SUB TOTAL $1,267,150
MOBILIZATION 10% $126,715
SUB TOTAL -BRIDGE TTEMS $1,393,865
COST PER SQUARE FOOT i 167
CONTINGENCIES @ 25% $348,466
TOTAL $1,742,331
FOR BUDGET PURPOSES - SAY $1,745,000
Note: Cost estimate with likely unit prices and additional items of work. Based on quantities by Moffat and Nichol Engineer's
estimate and unit prices by Simon Wong Engineering.
C-4
• GENERAL PLAN ESTIMATE OR
Preliminary Cost Estimate Worksheet
BRIDGE REPLACEMENT
M PLANNING ESTIMATE
BRIDGE CARLSBAD BOULEVARD OVERHEAD BRNO 57C-0134 REC'D BY
TYPE CAST-IN-PLACE T-BEAM DIST 11 |C0 SD RTE 1
LENGTH 165 X WIDTH 50.7 =AREA 8,366 ft^
DESIGN SECTION QUANTITIES BY DATE ESTIMATE NO.
PROJECT INCLUDES QUANT. CHECKED BY DATE PRICE BY
AND $ ROADWORK CHG UNIT ANDEA COST INDEX
NO. CONTRACT ITEMS UNIT QUANTITY PRICE AMOUNT
1 REPLACE BRIDGE SF 8,366 $150.00 $1,254,825
2 TRAFFIC CONTROL LS 1 $50,000 $50,000
3 MISC. ROAD WORK LS 1 $50,000 $50,000
4 RAILROAD FLAGGING DAY 200 $280.00 $56,000
5 NCTD REVIEW & PERMITTING LS 1 $30,000.00 $30,000
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
SUB TOTAL $1,440,825
MOBILIZATION 10% $144,083
SUB TOTAL - BRIDGE rTEMS $1,584,908
COST PER SQUARE FOOT $ 189
CONTINGENCIES @ 25% $396,227
TOTAL $1,981,134
FOR BUDGET PURPOSES - SAY $1,985,000
Note: Preliminary cost data does not include Caltrans oversight, design and construction engineering costs.
c-5
Appendix D
PRELIMINARY GEOTECHNICAL RECOMMENDATIONS
D-1
'GROUP!
iDELTAi
CONSULTANTS
Certified mE
Gi-i>h'Chniciil
C<M<t.ilin:.
H\/iiuilii\^ij
}{ijdnjtilic>
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Euvinmmnim!
CjiCiKiVMiiy
March 5, 2001
Simon Wong Engineering
9968 Hilbert Street, Suite 202
San Diego, CA 92131
Attention: Mr. Mark Creveling
Subject: Recommended Geotechnical Parameters
Carlsbad Boulevard Overhead (Bridge No. 57C-134)
Seismic Retrofit Project
San Diego County, California
Group Delta Project No. 1-147
Dear Mark:
In response to your request, we are pleased to provide you our recommendations
regarding the seismic retrofit design of the existing Carlsbad Boulevard Overhead
Bridge. The bridge is located along Carlsbad Boulevard approximately 0.6 mile
northwesterly of Elm Avenue (see Figure 1).
Review of Existing Data
We have reviewed the Preliminary Qeotechnical Report dated May 23, 1997 and the
Liquefaction Report dated August 12, 1997 prepared by Group Delta Consultants
(GDC) as part of the Local Agency Seismic Retrofit Project. There was no Log of
Test Borings (LOTB) available for the bridge. GDC performed two hollow-stem
auger borings (BH-l and BH-2) on June 6, 1997 to investigate liquefaction potential
at the bridge site. The boring logs and laboratory test data are provided in
Appends A. The Boring Location Plan is shown in Figure A-1 in Appends A.
Subsurface Conditions
Based on the results of field investigation by GDC, soils at the bridge site consist
mostly of clayey sand to sandy clay (SC7CL) fill soils, overlying terrace deposits
consisting of dense to very dense silty to clayey sands (SM/SC) and poorly graded
sand (SP). A clayey sandstone bedrock (Santiago Formation) was encountered
below the fill and terrace deposits at about El. 4-24 ft in boring BH-l and El. -f 14 ft
in boring BH-2. A soil cross-section below the bridge is shown in Figure 2.
Groundwater was not encountered in boring BH-l. A perched groundwater was
encountered in boring BH-2 at El. +14.5 feet.
92 Argonaut, Suite 120 • Aliso Viejo, California 92656-4121 • (949) 609-1020 wice • (949) 609-1030/ox
Torr.nncf, Cnlifornin • (.110) .•?20-5K)0 S.in Diego, C.Tliforni.T A (H58) 573-1777
www.GroiipDelta.com
Recommended Geotechnical Parameters
Carlsbad Blvd. Overhead
Simon Wong Engineering
GDC Project No. 1-147
Recommended Soil Parameters
April 5, 2001
Page 2
At your request we are providing soil parameters for each major soil type
encountered. The soil parameters include unit weight (y), friction angle ((j)), cohesion
(c), soil modulus (k), and strain at 50% of ultimate stress (850). In addition, we are
also providing ultimate and allowable bearing capacities and coefficient of friction.
The recommended geotechnical parameters are summarized in Table 1.
References
Group Delta Consultants, 1997, "Preliminary Geotechnical Report, Local Agency
Seismic Retrofit Project, Bridge No. 57C-134, Carlsbad Overhead, San Diego
County, California," prepared for Moffatt & Nichol Engineers, dated May 23, 1997.
Group Delta Consultants, 1997, "Liquefaction Report, Carlsbad Overhead, Bridge
No. 57C-134, Local Agency Seismic Retrofit Project, San Diego County, California,"
prepared for Moffatt & Nichol Engineers, dated August 12, 1997.
Attachments
The following table, figures and appendbc are attached and complete this letter
report:
Table 1 Summary of Recommended Geotechnical Parameters
Figure 1 Site Location Map
Figure 2 Soil Cross Section
Appendbc A Existing Geotechnical Data
DjELTA
1147-Rercommended Geotechnical Parameters.doc
Recommended Geotechnical Parameters
Carlsbad Blvd. Overhead
Simon Wong Engineering
GDC Project No. 1-147
April 5, 2001
Page 3
We hope this report meets your immediate needs. We appreciate the opportunity to
assist you in this important project. If you have any questions, please call us at (949)
609-1020.
Very truly yours,
GROGP DELTA CONSULTANTS, INC.
Carlos V. Arninte, P.E.
Project Engineer ^^j-t /
Kul Bhushan, Ph.D.,
President y
GROUP
DELTA 1147-Rercommended Qeotechnical Parameters.doc
TABLES
GROUP
IDELTA
TABLE 1
SCIMMARY OF RECOMMENDED GEOTECHNICAL PARAMETERS
CARLSBAD BOULEVARD OVERHEAD (BRIDGE NO. 57C-134)
SEISMIC RETROFIT PROJECT
Soil
Type
Y
(psO (defl.)
C
(psf)
k
(pel)
^50 Ultimate
Bearing
Capacity
(ksf)
Allowable
Bearing
Capacity
(ksf)
Frietion
Coefficient
Fill 120 0 2,000 500 0.01 10 3 0.35
Terrace
Deposits
125 38 0 225 N/A 25 5 0.50
Bedrock 130 0 5,000 2,000
-
0.005 25 5 0.50
The Base Map is fi-om the USGS 7.5 niinute
San Luis Rey, Califomia Quadrangle, 1968,
Photorevised 1975
A Approx. Scale
1:24000
GROUP PROJECT NO. 1-147
DELTA
Site Location Map
Carlsbad Overhead
FIGURE 1
FIGURES
BR/DGf:
SAA/iyjOGO COUNTT
scA.Lj:--'^ri'/(y-C'
APPENDIXA
EXISTING GEOTECHNICAL DATA
APPENDIX A
A.1 Introduction
The subsurface conditions at the project site were investigated by Group Delta
Consultants on June 6, 1997 by performing two soil borings shown in Figure A-1, Boring
Location Plan. A summary of the soil borings is presented in Table A-1. The results of
field investigation and laboratory testing are summarized in Table A-2.
A.2 Field Investigation
The borings were advanced utilizing a CME 95 hollow-stem drill rig. The borings had a
hole diameter of about 8 inches. The borings were performed by West Hazmat Company
under a continuous technical supervision of a Group Delta representative, who visually
inspected the soil samples, maintained detailed logs of the borings, interpreted
stratigraphy, classified the soils, and obtained split-spoon Standard Penetration Test
(SPT) samples at 5 ft interval. The soils were classified in the field and fiirther examined
in the laboratory in accordance with the Unified Soil Classification System (Figure A-3).
Field classifications were modified, where necessary, on the basis of laboratory test
results.
Soil samples were obtained using Standard Penetration Tests which were performed in
accordance with ASTM D1586-82 using a 2-inch outside diameter and 1.375-inch inside
diameter split-spoon barrel sampler. The SPT sampler was driven with a 140-pound
safety hammer dropping 30 inches.
The Standard Penetration Test consists of counting the number of hammer blows it takes
to drive the sampler 1 foot into the ground. SPT blowcounts are often used as an index of
the relative density and resistance of the sampled materials.
A.3 Laboratory Testing
Soil samples were carefiilly sealed in the field to prevent moisture loss. All the samples
were then transported to our laboratory for examination and testing. Tests were performed
on selected samples as an aid in classifying the soils and to evaluate their physical
properties and engineering characteristics. All tests were performed in general accordance
with appropriate Caltrans Testing Methods (CTM). Brief descriptions of the laboratory
testing program and test results are presented below.
A.3.1 Soil Classification
The subsurface materials were classified using the Unified Soil Classification System, in
accordance with ASTM Test Methods 02487-85 and D2488-84. The soil classifications
are presented on the boring logs in Appendix A and summarized in Table A-2.
A.3.2 In Situ Moisture Content
Moisture content and dry density were determined for selected samples. The drive
samples were trimmed to obtain volume and wet weight then were dried in accordance
with CTM 226. After drying, the weight of each sample was measured, and moisture
content and dry density were calculated. The moisture content of selected SPT samples
and bulk samples were also determined. Moisture content values are presented on the
boring logs in Appendix A and summarized in Table A-2.
A.3.3 Grain Size Distribution and Wash Analysis
Representative samples were dried, weighed, soaked in water until individual soil
particles were separated, and then washed on the #200 sieve. The portion ofthe material
retained on the #200 sieve was oven-dried and then run through a standard set of sieves in
accordance with CTM 202. The results of grain size distribution tests performed are
graphically shown in Figure A-2. The relative proportion (or percentage) by weight of
gravel, sand and fines (silt and clay) are determined from Figure A-2 and summarized in
Table A-2. The percentage of fines (i.e., soil passing #200 sieve) is an important factor
for evaluating the liquefaction potential of sandy soils. Fines content were determined for
selected sandy soil samples which may liquefy. The results are presented in Table A-2.
A.4 Boring Logs
Detailed logs of the soil borings including blowcount data and in situ moisture content
and dry densities are presented in Figures A-4 through A-5. Laboratory tests performed
other than the moisture content and dry density determination are shown on the boring
logs in the column "Other Tests". The following abbreviations are used on the logs to
indicate the type of test performed.
GS Grain Size Distribution Test
WA Wash Analysis / Fines Content Determination (% Passing #200 Sieve)
A.5 List of Attached Tables and Figures
The following tables and figures are attached and complete this appendix:
Table A-1 Soil Boring Summary
Table A-2 Summary of Field and Laboratory Test Results
Figure A-1 Boring Location Plan
Figure A-2 Grain Size Distribution
Figure A-3 Key for Soil Classification
Figures A-4 through A-6 Boring Logs (BH-1 through BH-2)
TABLE A-1
SOIL BORING SUMMARY
CARLSBAD OVERHEAD (BRIDGE NO. 57C-134)
LOCAL AGENCY SEISMIC RETROFIT PROJECT
Boring Station Offset from Surface Total Groundwater Associated Excavation
No. No. Centeriine Elevation Depth Depth Foundation Equipment
(ft) (ft) (ft) (ft) Support
BH-l 477+70 28.0 LT 49.0 30.5 • Bent 6 CME 75
BH-2 480-H3 48.7 LT 39.0 46.0 24.5 ** Bent 1 CME 75
* Groundwater not encountered
** Perched groundwater encountered
TABLE A-2
SUMMARY OF FIELD AND LABORATORY TEST RESULTS
CARLSBAD OVERHEAD (BRIDGE NO. 57C-134)
LOCAL AGENCY SEISMIC RETROFIT PROJECT
Boring
No.
Sample
Depth
(ft)
USCS
Soil
Type
Equiv. SPT
Blowcount
(blows/ft)
Moisture
Content
(%)
Dry
Density
(pcf)
Gravel
Content
(%)
Sand
Content
(%)
Fines
Content
(%)
Liquid
Limit
(%)
Plastic
Limit
(%)
BH-I 5-6.5 * CL 16 BH-I
I0-1I.5 CL 26 18.3 109.6
BH-I
15-16.5 SC 33 10.7 33.8
BH-I
20-2 L5 SC 16 10.5 21.5
BH-I
25-26.5 SC >100 9.8 120.4
BH-I
30-30.5 SC > 100 11.1
BH-2
K
1-2 * SC 43 BH-2
K
5-6.5 SC 32 6.3 29.1
BH-2
K
10-1 L5 SM/SC 37 5.7 0 76.5 23.4
BH-2
K
15-16.5 SM/SC 45 5.6 16.0
BH-2
K
20-21.5 SP 81 8.0 0 90.1 9.9
BH-2
K
25-26.5 sc 86 6.9 19.6
BH-2
K
30-31.5 SC 73 ILO
BH-2
K
35-36.5 sc 71 12.7 30.5
BH-2
K
40-41.5 sc 71 ILl
BH-2
K
45-46 * sc 87
No sample recovery
res'-oh't
etnts Benfs Bint 4
ELEVATION
ls'-o'±_^ 30'-7'f . selah'*. sd-y't
PLAN
/" =50'
PROJECrrNO.I-lll
Group Delta
Consultants
CARLSBAD OVERHEAD, BRIDGE NO. 57C-134 (SAN DIEGO COUNTY, CALIFORMA)
BORING LOCATION PLAN
(REFERENCE: GENERAL PL^N, CARLSB/\D BOULEVARD OVERHEAD)
BH-l
Figure A-1
C:\PR0JECrSVV10FFAmRErR0n'R57C134BP.GRF
100
C3
CO
w
E-. iz; w u
a,
UNIFIED SOIL CLASSIFICATION
COBBLES GRAVEL SAND
SILT OR CLAY COBBLES COARSE HNE COARSE MEDIUM 1 RNE SILT OR CLAY
U.S. SIEVE SIZE IN INCHES U.S. STANDARD SIEVE No. HYDROMETER
12 6 3 3/4 1/2 3/8 4 10 20 40 60 140 200
-i f
Mill 1—r 1 1". IIII—1 1'-\ III r -1—1— M 1 1 1 'i 1 TTI
0
20
40
ffi
Q
E-i
60 g
U
cu
80
100
GRAIN SIZE IN MILLIMETER 10"^
SYMBOL BORING °fft)™ DESCRIPTION
O
•
BH-2
BH-2
10-11.5
20-21.5
SM/SC
SP
Remark
Project No. I-111
GROUP DELTA
CONSULTANTS, INC.
CARLSBAD OVERHEAD
GRAIN SIZE DISTRIBUTION Figure No. A-2
PRIMARY DIVISIONS GROUP
SYMBOL SECX)ND/iJJY DIVISIONS
« ^
Q 5
81
<3 §
LU £
tr e
8^
GRAVEL
(Mo/B Ttw\ 12%
Fines)
S c „ 01 J5 S ?
51 4 V
Ir
CUEAN
GRAVEl^
(/.ass TTian S%
Fines)
GW Well Graded Gravels, Gravels Wth Sand, UUe Of No Fines.
GP Pooriy Graded Gravels, Gravels WSh Sand, UUa Or No Hnes.
GM SUly Gravels. SUty Gravel WIUi Sand, Non PlosUc Floes.
GC Clayey Gravels, Clayey Gravel With Sand, Ptasllc Fines.
CtXAN SANDS
(Less Than 5%
Fines)
SW Wall Graded Sands. Sand WUh Gravel, UUa Or No Fines.
SP Pooriy Graded Sands, Utile Or No Fines.
SANDS
(More Than 12%
Fines)
SM SUly Sands, Sand-Sill Mixtures. Non-Plasllo Fines.
SC Clayey Sands, Sand-Clay MWures. PlasUc Fines.
21 — u
O n _ S
Q P «
UJ p 2
u. 5
52?
r— —' ^ c, c d O 5 -J ra
W Q e
<
ML Inorganic SIKs and Very Fine Sands, Rock Fkxir, SUy or Clayey Fine Sands or
Clayey Sills Wnh Sllqhl Plaslldty.
CL Inorganic Clays o( Low lo Medium Plaslldty. Gravelly Clays, Sandy
Clays, Silly Clays, Lean Clays.
OL Organic SIHS and Organic SlBy Clays ol Low Plaslldty.
MH Inorganic Basllc SIJs, Micaceous or Dlamaoeous Fine Sandy orSUty Soils, Plastic Sills.
CH Inorganic Clays or High Plasticity, Fat Clays.
OH Organic Clays o( Medium to High PlasUclty, Oiganlc Sills.
HIGHLY ORGANIC SOILS PT Peal and Olher Highly Organic Soils.
Dual Gtoup Symbola Ara Used For Coarse Grained Solla With 6% To 12% Fines (Passing #200 Sieve) And For (CL-ML).
Borderiine Classificalion May Be Represented With Two Symbols Separated By A Slash.
Number of Blows of 140 Pound Hammer ;'\QONs\sTENCY,CLASsiFlCAflbN, '5,?
GRANULAR COHESIVE
Consistency BiowsyFoot* Consistency Blows/Foot* Strength"
Very Loose 0-4 Very Soft 0-4 0-1/2
Loose 5-9 Soft 5-9 1/2-1
Slightly Compact 10-19 Stiff 10-19 1-2
Compact 20-34 Very Stiff 20-34 2-4
Dense 35-69 Hard 35-69 Over 4
Very Dense >70 Very Hard >70 -
Falling 30 Inches To Drive a 2-Inch O.D.
(1-3/3 Inch I.D.) Split Banel Sampler
(ASTM 0-1536 Standard Penelnation
Test).
"Shear SUenglh In KSF.
Read From Pocket Penetrometer.
PLASTICITY CHART
60
Q.
•^40 •S
7 4
0.
I I /
.9./]
Ct .or( )L V
0
9 M ^or DH
ML ( "1-M ML
CLAYS AND SILTS SAND GRAVEL COBBLES BOULDERS CLAYS AND SILTS Fine Medium Coarae Fine Coarse
COBBLES BOULDERS
Sieve Sizes 200 40 10 4 3/4' 3' 12*
U.S. STANDARD SERIES SIEVE CLEAR SQUARE SIEVE OPENINGS
Classification of Earth Malerials is Based on Field Inspection and Should Not Be Construed To Imply
Laboratoiy /knalysl^Unlesa So Staled.
GWandSW:C.,= --S2-GreaterThan4ForGWand6ForSW; Cc = (D30) Belween 1 and 3
20 40 60
Liquid Umil (LL)
GP and SP: Clean Gravel or Sand Not Meeting Requirament For GW and SW.
GM and SM: Atterberg Limit Below 'A' Line or P.I. Loss Than 4.
80 100 GC and SC: Atterberg Umil Above'A'Line P.I. Greater Than 7.
KEY FOR SOIL CLASSIFICATION FIGURE A-3
on
Oi W nc H o
OS
6?
WA
WA
18.3
10.7
10.5
109.6
9.8
11.1
120.4
OQ
16
UJ
a,
26
tti;
Q
DESCRIPTION OF SUBSURFACE MATERIALS
THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME W
DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHAMrc
AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED irA SrPLIFICATON
OF ACTUAL CONDITIONS ENCOUNTERED. siMmHCATION
D
33
16
>100
>100
SAMPLE TYPES
[C] Rock Core
[S] Standard Split Spoon
[DI Drive Sample
dl Bulk Sample
[T] Tube Sample
10-
-D-
15-
20-
25-
30-
35-
Fifli
Clayey SAND (SC),
brown, damp, loose to slightly compact
Sandy CLAY (CL),
brown gray, moist, stiff to very stiff,
with trace of gravel
No sample recovery
z o
^?
> s
tti
m
49
45
Clayey SAND (SC), '
brown, moist, slightly compact to compact
•40
35
Sand lens
Gravels and cobbles
Santiago Formation:
Clayey SANDSTONE (SC),
light gray, moist, very dense
Harder drilling
\Auger refusal
Boring terminated at Elev. 18.5 ft
Groundwater not encountered
DATE DRILLED:
6-6-97
EOUIPMENT/lVlETHOD USED:
CME 95/HSA
SUPERVISOR:
G. SPAULDING
PROJECT NO. 1-111
CARLSBAD OVERHEAD
SAN DIEGO COUNTY, CAUFORNIA
-30
•25
20
15
10
LOG OF BORING NO. BH-1
PAGE 1 OF 1 FIGURE A-4
1/3
X
H
O
WA
B5
O
CO
as >-
Q
6.3
GS
WA
GS
5.7
5.6
^8
CQ
43
32
IX, Q
DESCRIPTION OF SUBSURFACE MATERIALS
37
8.0
WA
WA
12.9
11.0
12.7
45
81
86
THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF
DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGF
AT THIS LOCATION WITH THE PASSAGE OF TIME. THE OATA PRESENTED IS A SIMPLIFICATION
OF ACTUAL CONDITIONS ENCOUNTERED. oimrui-JUA I ION
73
71
Terrace Deposits:
Clayey SAND (SC),
red brown, damp, compact to dense
Silly to Clayey SAND (SM/SC),
mottled brown/gray/red, damp, dense
20-
25-
30-
35-
SAMPLE TYPES:
[C] Rock Core
[S] Standard Split Spoon
|D1 Drive Sample
(H Bulk Sample
ITI Tube Sample
Poorly Graded SAND with Silt (SP),
brown, damp, very dense
•35
30
25
2, Perched groundwater at Elev. 14.5 ft
Santiago Formation:
Clayey SANDSTONE (SC),
light olive gray, moist, very dense
DATE DRILLED:
6-6-97
EQUIPMENT/METHOD USED:
CME 95/HSA
SUPERVISOR:
G. SPAULDING
PROJECTNO. 1-111
CARLSBAD OVERHEAD
SAN DIEGO COUNTY, CALIFORNIA
20
15
10
LOG OF BORING NO. BH- 2
PAGE 1 OF 2 FIGURE A-5
OJ
tti a: H O
11.1
CO
>-oi Q
CO 3 <n . o "a >u ^
[11 -J pa
71
87
m
o. Q
40-
DESCRIPTION OF SUBSURFACE MATERIALS
THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF
DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE
AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATK)N
OF ACTUAL CONDITIONS ENCOUNTERED aiMrum,A I ION
45-
SAMPLE TYPES:
[c] Rock Core
[S] Standard Split Spoon
|D1 Drive Sample
[B] Bulk Sample
in Tube Sample
50-
55-
z o
w
w
A^Auger refusal
Boring terminated at Elev. -7 ft
Perched groundwater encountered at Elev. 14.5 ft
-10
60-
65-
70-
75-
DATE DRILLED:
6-6-97
EQUIPMENT/METHOD USED
CME 95/HSA
SUPERVISOR:
G. SPAULDING
PROJECT NO. 1-111
CARLSBAD OVERHEAD
SAN DIEGO COUNTY, CALIFORNIA
-15
-20
-25
-30
-35
-40
LOG OF BORING NO. BH- 2
PAGE 2 OF 2 FIGURE A-6
TABLE 1
SUMMARY OF PRELIMINARY
SEISMIC, GEOLOGIC, AND FOUNDATION INFORMATION
Bridge Name:
Bridge No.:
Carlsbad Overhead
57C-134
Geologic Data: ~ ' ~ •—
Based on Log of test Borings for Elm Avenue Undercrossing and the Las Flores Overcrossing
bridges, soils consist of compact to dense sands and silty sands.
GWS: No groundwater data is available at the site. In Elm Avenue bridge site, groundwater is
about 3 to 6 ft below the surface, while in Las Flores Drive bridge site, groundwater
is about 42 to 45 ft below the surface.
Earthquake Data : Lat. 39° 9.8'N
Long. 117° 21.2' W
Fault: Offshore Zone of Deformation (Rose Canyon Fault) Magnitude: 7.0
Distance to Site from Fault:
Horizontal Bedrock Acceleration (max): 0.45 g
SOIL PROFILE TYPE FOR ARS CURVES (ATC-32): Figure R3-8
(B) (C) (E) (A) (F)
Liquefaction Potential: Low Med High.
"As-Built" Foundation :
Piles: Not Used Spread Footings: Used
Pile Type(s): N/A Allowable Bearing Pressures: N/R
Design Load: N/A
Allowable Bearing Pressures: N/R
Est. Ultimate Compression Load for Retrofit: N/A
Est. Ultimate Uplift for Retrofit Design: N/A
Scour Potential: Yes No
Remarks :
Additional Drilling Required: Yes No
PRELIMINARY GEOTECHNICAL REPORT
SEISMIC RETROFIT PROJECT
BRIDGE NO. 57C-134
CARLSBAD OVERHEAD
SAN DIEGO COUNTY, CALIFORNIA
1.0 GENERAL
1.1 Background
The County of San Diego is considering the Carlsbad Overhead (Bridge No. 57C-134) for
seismic retrofit. The bridge site is shown m Figure 1. The bridge is located along
Carlsbad Boulevard approximately 1.0 km (0.6 mi.) northwesterly of Ehn Avenue.
1.2 Existing Design Information
We have reviewed plans of the Carlsbad Overhead provided to us by Moffatt & Nichol
Engmeers. The pertinent bridge plans used in our study are presented in Appendix A.
The existing bridge was built in 1925 by Califomia Department of Transportation
Division of Structures under Contract No. M-111. In 1935, the bridge was widened. The
bndge has five spans with individual span lengths varying fi-om 8.2 to 13 7 m pi to 45
ft). The total length of the bridge is 50.3 m (165 ft) and the bridge is skewed to the right
by 454 degrees. The net width of the bridge is 13.7 m (45 ft) vWth an overall width of
15.7 m (51.5 ft). The bridge consists of five simple CIP/RC "T" beam girder spans
supported by two closed-end backfilled reinforced concrete strutted column bent
abutments and four reinforced concrete column bents. All bridge foundations are shallow
foundations.
1.3 Scope of Work
In general, the purpose of our investigation was to review the existing foundation data
and to develop parameters for the seismic retrofit evaluation. Our scope of work consisted
of: a bnef site visit and reconnaissance, review of as-built plans, evaluation of
geotechnical foundation parameters, and preparation of this report.
Specifically, we assessed the foiiowing geotechnical mformation:
Spring constants for spread footings,
Lateral resistance for abutment walls and spread footings.
Ultimate bearing capacity, and
Liquefaction potential
C:\PROJECTS\MOFFATT\RETROFmBR57CI34.DOC
Carlsbad Overhead GDC Project No. I-11 i
Moffatt & Nichol Engineers Pagg 2
1.4 Pertinent Reports and Investigations
Our understanding of this project is based on discussions with Moffatt and Nichol
Engineers, our site visit, and our review of the available plans and bridge summary
report. A list of references reviewed is provided in Section 5.0.
2.0 PRELIMINARY SEISMIC, GEOLOGIC, AND FOUNDATION DATA
A summary of existing conditions, and seismic design considerations is presented in
Table 1. Additional as-buih foundation details are summarized in Table 2.
3.0 DISCUSSION AND RECOMMENDATIONS
3.1 Soil Conditions
No Log of Test Boring was provided for this bridge. . However, Logs of Test Borings
fi-om the Ehn Avenue Undercrossing and the Las Flores Drive Overcrossing bridges were
available (see Appendix B). These bridges are within approximately 1.1 km (0.7 mi.)
fi-om^ the subject bridge. The subsurface mvestigation at the Ehn Avenue Undercrossing
consisted of three driven cone borings. The depths of exploration ranged from Elevation
23.6 to 18.6 m (75.5 to 61 ft). The soils encountered consisted of silty sands, sands, and
sandy gravel. Penetration resistances in excess of 100 are reported m the logs.
The subsurface investigation at the Las Flores Drive Overcrossmg consisted of advancing
two 2.5-cm (1-in.) sample borings. The zone of exploration was from Elevation 23.8 to
8.5 m (78 to 28 ft). The soils encountered mcluded sands and silty sands. The penetration
resistances ofthe 2.5-cm (1-in.) sample borings varied between 100 to 4000 blows per
foot.
Based on our site visit at the Carlsbad Overhead, we noted that exposed soils consisted of
formational soils comprised of cemented sands and sandstones. No evidence of seepage
was noted. The approximate ground surface elevation undemeatii tiie bridge is 7.3 m (24
For purposes of our smdy, we assumed tiiat the subsurface soils are generally comprised
of compact to dense sands and silty sands. We assumed the soils had an equivalent
standard penetration test (SPT) blowcount of 30 and average total unit weight of 1 97-^
kg/m'(120 pcf). 5 - ~
3.2 Groundwater Conditions
Groundwater was encountered in Elm Avenue bridge site between Elevations 21 and 71 8
m (69 and 71.5 ft) or approxunately 0.9 to 1.8 m (3 to 6 ft) below tiie ground surface. In
Las Flores Dnve bndge site, groundwater was reported to be between Elevations 12 8 to
14.0 m (42 to 46 ft) or approximately 9.45 to 10.4 m (31 to 34 ft) below the ground
C:\PROJECTS\MOFFATnR£TROFn\BR57C 134.DOC
Carlsbad Overhead ^i-v^ n_ • v,
Moffatt & Nichol Engineer. " '
Page 3
surface. Therefore, a potential for shallow groundwater at tiie Carlsbad Overhead bridee site exists. •^i^^B^
33 Seismic Parameters
33.1 Response Spectra
It is our understanding tiiat tiie Departoient of Transportation (Caltrans), Engineenng
?vXd B^X w'°^ ''^''''1 a recommended response spectra for'tiie Carlsbad
overhead Bndge. We recommend usmg a bedrock acceleration of 0.45g and ATC-32
figure R3-8 for response spectra.
Our response spectra recommendations are based on our review of tiie faults in tiie
general area of tiie bridge as well as DMG OPEN-FILE-REPORT 92-1 According to
our review, tiie controlling fault for tiie Carlsbad Overhead Bridge is tiie Offshore Zone
of Defonnation (Rose Canyon Fault). The magnitude associated witii tiiis fault zone is
reported to be 7. The estimated bedrock acceleration for tiie Carlsbad Overhead site is
ITcnT" ^' ^^""^^^^^ subsurface soil profile as Type D per ATC-32
3.3.2 Spread Footings
All foundations are supported on spread footings. A summary of as-built foundation
dmiensions and charactenstics are .presented in Table 2.
TTie ultimate bearing capacity of tiie spread footings was estimated by assuming a
friction angle of 32 degrees. Spring constants for tiie spread footings were estir^ed by
nTlLT '""I'-^'T ^-^^ °" --gy blow c"d pubhshed con-elation by Sykora (1987) shown m Figure 2 and dynamic spring constat
loT h, fr^^'f • '^^ '^^^^^^^^ ^P^S '^"-^^^ strain values ^d " applicable at small displacements. They should be considered as initial values for
T^l^lT''''- displacements using tiie spring constants are uch t^a
tiie ultmiate beanng capacity or lateral resistance is exceeded, softer springs should be
exceeded " ^^^-^ rLisL^ot
P^'^Jvrson re^ " ' and haZV, r ^^^°™"^"dations, we have provided design parameters for
shlg In adS on f^^^^^ "^^"^^ -"^^ution from
xcTvations at^h^^^^^^^^^^^ '^'""'''^ ^^"^^^ tiiat tiie footing excavations are backfilled witii compacted granular fill.
?^Z1ZT' ^P""^ '^^'^ P--"^^- - ^-"niarized in
C:\PR0JECTS\M0FFAmRETR0FmBR57CI34.DOC
Carlsbad Overhead r-n/- D- • v, , ,, P. XI- u . r- . GDC Project No. -Moffan & Nichol Engineers „
Page 4
3J.3 Pile Foundations
Pile foundations were not used for this bridge.
33.4 Lateral Load Pile Response of Outer Bent Columns
At tiie request of Moffatt and Nichol, we evaluated tiie lateral load pile response of tiie
'^^fJi^''^ '^^'^^ °^ *e b^dge using tiie finite difference computer program PILED/G
(GEOSOFT, 1988). The program uses non-linear (p-y) soti resistance-lateral deflection
curves fo represent soil characteristics. These columns extended from tiie bridge deck to a
deptii of 1.8 fo 3 m (6 fo 10 ft) below tiie ground to tiie top of tiie footmgs. The columns
were compnsed of 0.6-m (2-ft) square reinforced concrete columns. As requested by
Moffatt and Nichol, we applied tiie lateral load at tiie ground surface, considered both
free and fixed head conditions, and used 40 percent of tiie EI of tiie column We
understand tiiat Moffatt and Nichol models tiie bridge and bridge colmmis as stmctm-al
elements witii tiie buried portion of tiie column and associated foundations modeled as an
eqmvalent stmctural element The.characteristics of tiiis equivalent elemem are developed
from tiie results of our. analyses. Due fo tiie relative shallowness of tiie column
embedments, tiie lateral load response of tiie columns conesponded fo tiie behavior of a
short, ngid pile. The variation of pile deflection, pile moment, and shear witii deptii for
tiie cases evaluated are presented as Figures 3 tiirough 8. A summary of tiie variation of
pile displacement at tiie ground surface and maximum pile moment witii applied load is
presented m Table 5.
33.5 UltimateLateralCapacity of Abutment Walls
-Hie ultimate lateral capacity of an abutment wall is a fimction of tiie height of tiie
abutment wall which is acted on by tiie passive soil pressure on tiie backfill We have
provided recommendations for tiie average ultimate passive soil pressure acting on the
abutmem wall. This dynamic value is based on a passive pressure coefficient of 10 3 for
tiie compacted backfill providing an average pressure of 239 kPa (5 ksf) for an 2.4-m (8-
ft) high wall. The ultimate static lateral pressure was increased by (1/0.65) to account for
short-tenn dynamic loadmg and use of peak ground acceleration. The ultimate lateral
capacity for wall heights 2.4 m (8 ft) and above should be taken as 369 kPa (7 7 ksf) For
wall heights less than 2.4 m (8 ft), we recommend tiiat tiie ultimate capacity be obtained
metTs im^R? f 7-'i^^ ^^^-^^ -^^^^ " ''^he wall height in
i n n?'t? P''''^'^ ^°b^"^ed when tiie deflection of the
wall reaches 0.02 H meters (or feet), where H is tiie wail height in meters (or feet). The
7^T,"u t^'^'n'.^'^! ^''^"^^^ "'^^^^e ^^'^^^ ^apa^ity of til wall divided by tiie wall displacement.
3.4 Liquefaction Potential
Groundwater data for thc site is unavailable. Although there is a potential for shallow
groundwater at the s.te, based on borings a. nearby bridge sites, our preliminary esttaat"
C:\PROJECTS\MOFFATT\RHTROFmBR57C134.DOC
Carlsbad Overhead /-r„- D, • v, , N^^ff-o« i XI- u • r- . Project No. -in Moffan & Nichol Engineers
" Page 5
of liquefaction potential for Carlsbad Overhead is low. However, since tiiere is no Log of
Test Borings available for tiiis bridge, we recommend drilling two borings and
conductmg additional liquefaction analysis based on tiie results of tiie new subsurface
data.
4.0 LIMITATIONS
No field mvestigation was perfonned at tiie sites. In view of past grading and tiie general
geology Of tiie area, possibility of different conditions can not be discounted It is tiie
responsibility of tiie owner fo bring any deviations or unexpected conditions observed
dunng constmction fo tiie attention of tiie Geotechnical Engineer. In tiiis way any
reqmred supplemental recommendations can be made witii a minimum of delay.
This report was prepared in accordance witii generally accepted geotechnical engineering
pnnciples and practice. The professional engineering work and judgments presented in
tins report meet tiie standard of care of our profession at tiiis time. No otiier warranty
expressed or implied, is made. '
5.0 REFERENCES
Available Dlan.s a.s fnllnwg-
State of California, California Highway Commission, "Bridge over Atchison Topeka &
Santa Fe RY. Near Carlsbad-Sta. 478+30.69, San Diego County": General Plans
abutment details, bent details, and miscellaneous plans dated 1925.
State of California, California Highway Commission, "Widening of Bridge over
Atchison Topeka & Santa Fe RY. Near Carlsbad-Sta. 478+30.69, San Diego County"-
General Plans and miscellaneous details dated 1934.
Log of Test Borings for "Ehn Avenue Undercrossing".
Log of Test Borings for "Las Hores Drive Overcrossmg".
References:
C.^i-fn'^-'^p^°'°^L^°''"'"' "Imvrovttl Seismic Design Criteria for California Badges: Provisional Recommendatfons".
C?''.^"T.^\^'^'"^' ^''^^^^^ P^'^"^' ^e^^g^' 1979. "Design of Stmcmres for Vibrating Machmes," Gulf Publishing Company, Houston, 1979, pp 191.
California Department of Conservation. Division of Mines and Geology 1992 "Peak
Site^DMC ^^^^^^ ^^^'^"^^ ^" -d Stiff Sol iites) . DMO OPEN-FILE REPORT 92-1.
C:\PROJECTS\MOFFAmRETROFmBR57CI34.DOC
Carlsbad Overhead nr^n v, , * xr u • r- . GDC Project No. -111 Moffatt & Nichol Engineers ^
^ Page 6
Department of Transportation, Engineering Service Center. Office of Stmcmral
Foundations-MS #5, Stmcmre Foundations Branch, 1996, "Acceleration Response
Spectra for Local Agency Seismic Retrofit Bridges", Memorandum, August 13 1996
Local Agency Seismic Retrofit Conttact No. 59Y025, EA 53-965100.
Earth Technology Corporation, 1986, Seismic Design of Highway Bridge Foundations
ra^riS)-8^/ToT ^'P'^'^' °^ Transportation, Report No.'
GEOSOFT, 1988. "PILED/G, Laterally Loaded Drilled Piers and Piles" A Finite
Difference Program for Calculating Lateral Load Response of Piles. 1442 Lincoln
Avenue, Ste. 146, Orange, CA 92667.
State of California Department of Transportation, 1990, Bridge Report, Carlsbad
Overhead (Carlsbad Boulevard - 0.6 miles northwesterly of Ehn Avenue FAU S352)"
May 22, 1990. ^ '
Sykora, D., 1987, "Examination of Existing Shear Wave Velocity and Shear Modulus
Conrelations in Soils", U.S. Department of tiie Anny, Waterways Experiment Station
Corps of Engmeers.
C:\PROJECTS\MOFFAmRFrROFmBR57C134.DOC
TABLE 1
SUMMARY OF PRELIMINARY
SEISMIC, GEOLOGIC, AND FOUNDATION INFORMATION
Bridge Name:
Bridge No.:
Carlsbad Overhead
57C-134
Geologic Data: No Log of Test Borings was available for this bridge. Based on Log of Test Borings for
Elm Avenue Undercrossing and the Las Flores Overcrossing bridges located approximately l.l km from
the subject bndge, soils consist of compact to dense sands and silty sands.
GWS: No groundwater data is available at the site. In Ehn Avenue bridge site, groundwater is
about 3 to 6 ft below the surface, while in Las Flores Drive bridge site, groundwater is about 42 to 45 ft
below the surface.
Earthquake Data Lat. 39° 9.8' N
_, , Long. 117° 21.2'W
Fault: Offshore Zone ofDeformation (Rose Canyon Fault) Magnitude: 7.0
Distance to Site from Fault: 7 km
Horizontal Bedrock Acceleration (max): 0.45 g
SOIL PROFILE TYPE FOR ARS CURVES (ATC-32): Figure R3-8
(A) (B) (C) (^W)
Liquefaction Potential: Low x * Med
(E) (F)
High.
"As-Built" Foundation : See Table 2
Piles: Not Used Spread Footings: Used
Pile Type(s): N/A
Design Load: N/A
Est Ultimate Compression Load for Retrofit: N/A
Est. Ultimate Uplift for Retrofit Design: N/A
.Scour Potpntial - •\/»,
Allowable Bearing Pressures:
See Tables 3 and 4
Remarks
' T?\"'^"'^!"-'°" ^""^^^ ^^^"^ °" ""^"^'l subsurface soil and groundwater data Ifthe conditions considered in the estimate differ from the acmal estimate, the liquefaction potential tor the site may be high.
Additional Drilling Required: Yes No
Kul Bhushan, Ph.D., G.E.
C:\PROJECTS\MOFFATnRETROFmBR57CI34.DOC
2.0
PERIOD (sec)
50
4-0
Curi/e Far
Cor/sbad O.H.
(045g)
0.7Q (0.7g)
PERIOD (sec)
Figure R3-8 Proposed ARS curves for soil type D (Af - 7.25 ± :0.25)
ATC-32 BDS-Recommendations, Section 3: Loads 37
TABLE 2: SUMMARY OF AS-BUILT FOUNDATION CHARACTERISTICS
Bridge Name: Carlsbad Overhead
Bridge Number: 57C-134
Local Agency Seismic Retrofit Project
GDC ProjectNo. 1-111 Group DelU ConsulUnts
5/29/97
1.
2.
3.
4.
5.
NOTES FOR TABLE 2: SUMMARY OF AS-BUELT FOUNDATION
CHARACTERISTICS
Location refers to the foundation element for which the information is provided (e.g. Abutment 1 or
Bent 2).
No. of Elements refers to the number of spread footing elements for the specified location. Example,
ifthe no. of elements is 2, there are two spread footings for the location.
L refers to the length ofthe spread footing or pile cap. Thc length ofthe foundation is the dimension
perpendicular to die longimdinal axis ofthe bridge. If there is more than one element, a range ofthe
lengths is provided.
B refers to the width ofthe spread footing or pile cap. The width ofthe foundation is the dimension
perpendicular to the transverse axis ofthe bridge. If there are more than one element, a range of the
lengths are provided.
T refers to the thickness of the spread footing of pile cap.
6. D refers to the embedment depth of the spread footing or pile cap as measured from the minimum
ground surface to the bottom ofthe footing or pile cap.
7. b.o.f. elev. refers to the estimated or reported elevation corresponding to the bottom of the spread
footing or pile cap.
8- refers to die plan reported allowable bearing pressure. If this values could not be obtained from
the plans, N/R (Not Reported) is shown. If there are no spread footings, N/A (Not Applicable) is
shown.
9. Type refers to the reported type of pile foundation used for die bridge.
10. Total refen to the total number of pile foundation elements in the specified pile cap If the number
could not be accurately confirmed, N/R (Not Reported) is shown. If there are no pile foundations
N/A (Not Applicable) is shown.
11. Vertical refers to number of pile foundation elements which are vertical. If the number could not be
accurately determmed, N/R (Not Reported) is shown. If there are no pile foundations N/A (Not
Applicable) is shown.
12.
14.
15.
Batter refers to number of pile foundation elements which are battered. If the number could not be
accurately determined, N/R (Not Reported) is shown. If there are no pile foundations. N/A (Not
Applicable) is shown.
13- Q^, refers to the plan reported design capacity of the pile foundation elemenc If this values could
not be obtained from the plans, N/R (Not Reported) is shown. If there are no pile foundations, N/A
(Not Applicable) is shown.
Pile Penetration refers to the length of pile foundation in the ground. If this information could not be
N/A m A°"'i ^ T'' "t"^ ^= ^"^^2^ ^"PP°"^d on spread footings, N/A (Not Applicable) is shown.
ZlIZ ''^'J^ '"'"^^ P*'*^ Pi'e foundation. If this
mformation could not be obtained from the plans. N/R (Not Reported) is shown. If the bridge was
supported on spread footings, N/A (Not Applicable) is shown.
16. This column is for additional comments.
TABLE 3: SUMMARY OF RECOMMENDED BRIDGE FOUNDATION CAPACITIES
Bridge Name: Carlsbad Overhead
Bridge Number: 570-134
Location
Bent 1
Bent 2
Bents
Bent 4
Bents
Bent 6
Wofes 1
Average Abutment Wall Pressure
p avg (ksO
H > 8 fl. H < 8 ft.
7.7
N/A
N/A
N/A
N/A
7.7x(H/8)
N/A
N/A
N/A
5 mob
(inches)
0.02*H
N/A
N/A
N/A
Type
Spread
Footing
Spread
Footini
Spread
Footing
Spread
Footing
Spread
Footing
Spread
Footing
Foundations'
Q ult (kips;
or
q ult (ksQ
20
15
15
15
Q up
(kips)
65
140
140
140
A axial
(inches)
N/A
N/A
N/A
N/A
P ult
(kips)
N/A
N/A
N/A
N/A
A lateral
(inches)
N/A
N/A
N/A
N/A
The foundation capacities shown are our best estimates. Since the Log of Test Borings for this bridge is
Lateral Resistance of Fooling or Pile Cap
Total Passive Force (kips)
Transverse Longitudinal
48
38
38
38
48
600
600
600
Sliding
Coefficient
0.45
0.45
0.45
0.45
not available, lhe actual foundation capacities may vary by 50 '
Local Agency Seismic Retrofit Project
GDC ProjectNo. 1-111 Group Delta Consultants
5/29/97
4.
NOTES FOR TABLE 3: SUMMARY OF RECOMMENDED FOUNDATION
CAPACITIES
Location refers to the foundation element for which die information is provided. For example, if the
location is Abutment 1, the informarion provided is for thc abutment
The recommended average ultimate abutment wall pressure for wall heights greater than or equal to
eight feet.
Ifthe wall height is less dian 8 feet, then die average abutment wall pressure is computed as follows:
p„g=7.7 X (H/8). This equation prorates die maximum wall pressure by die wall height divided bv 8
feet.
This column represents die wall displacement necessary to mobilize die average abutment wall
pressure. This displacement can be used widi die wall pressure to compute die equivalent abutment
stifftiess.
5. Type refers to die foundation type at die specified foundation location. For example, Spread Footing
refers to spread footings and Pile refers to pile foundations.
6. Ifthe foundation type is specified as Spread Footing dien die reported value refers to q.„ which is the
estimated ultimate bearing capacity of die spread footing. Conversely, if die foundation type is pile,
die value refers to Q^, which is die estimated ultimate axial capacity of a single pile foundation
element The q^, values shown apply for vertical loads only and do not take into account lateral loads.
For spread footings widi lateral loads ranging from 20 to 40 % of die total vertical loads,
approximately 20 to 60 % reduction in q^, values are anticipated.
7. If die foundation type is specified as spread footing, dien die ultimate uplift capacity of die footing
includes die weight of die footing and die soil above die footing. For a pile foundation die value refers
to die esrimated ultimate uplift capacity ofa single pile foundation element
8. The value specified is die axial displacement necessary to mobilize die ultimate pile capacity.
9. ?.„ refers to die ultimate lateral capacity of a single pile for die corresponding specified lateral
displacement
10.
11.
12.
13.
This column refers to die lateral pile displacement necessary to mobilize die ultimate lateral capacity
of die pile.
This value corresponds to die passive resisting force developed on die specified side of die spread
footmg or pile cap. This value does not include any lateral resistance from piles. This values is
assumed to be ftilly mobilized under a displacement equal to approximately 2 percent of the
foundation diickness.
This value conresponds to die passive resisting force developed on die specified side of die spread
footmg or pile cap. This value does not include any lateral resistance from piles. This values is
assumed to be ftilly mobilized under a displacement equal to approximately 2 percent of the
foundation diickness.
This value corresponds to die coefficiem of friction along die bottom of die spread footing This value
IS assumed to bc ftilly mobilized under a displacement equal to approximately 2 percent of the
foundation diickness. For pile foundation, N/A (Not Applicable) is shown.
TABLE 4: SUMMARY OF RECOMMENDED FOUNDATION STIFFNESS
Bridge Name: Carlsbad Overhead
Bridge Number: 57C-134
Local Agency Seismic Retrofit Project
GDC ProjectNo. 1-111 Group Delta Consultants
5/29/97
NOTES FOR TABLE 4: SUMMARY OF RECOMMENDED FOUNDATION
STIFFNESS
1-- Location refers to die foundation element for which die informarion is provided. For example ifthe
location IS Abumient 1, die information provided is for die abumient ^
2. The recommended foundation stifftiesses are for small-strain shear modulus values and dvnamic
spnng consmt formulas for rigid footings. Tlie calculated spring constants are small s^J^ vat^s^d
cTnsl'^' °H T^'/T"^"" displacements. If die calculated displacement^^ ^ng Zl slunt
constants are such diat die ultimate bearing and lateral resistances are exceeded, softer sjrin^s should
be used. Foundation displacements which would generate shear strains on die order of a S pe-
would result m a reduction of stif&iess on die order of 5 to 10 percent ^
^' '^^ZZl^^'"' f ? P'^^ ^"""^ "P°" ^'^ "'timate pile capacity and the displacement necessary reach die ultimate capacity.
^" '^l '"^^u"' "^u '"''"^ ^ ''^^'^ "P°" °^ lo^d analyses for vertical piles
?e t^^at:":iurForba« "'H™T ''^''^^^ '^^^ ^^^p'---^ ^^^^^^
die ukmiate value. For battered piles, die honzontal componem of die axial stiffness can be used
5. This column is for appropriate comments.
Appendix E
SHEAR WALL VS. SUPERBENT CALCULATIONS
Project:
Designed:
Checked:
i SIMON WONG ENGINEERING
STRUCTURAL & BRIDGE ENGINEERS
9968 Hibert Street, Suite 202
San Diego, CA 92131
(858) 566-3113
FAX (858) 566-6844
Page: ^ Ol
Proj. #:
Date:
Revised:
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Project:
Designed:
Checked:
SIMON WONG ENGINEERING
STRUCTURAL & BRIDGE ENGINEERS
9968 Hibert Street, Suile 202
San Diego, CA 92131
(858) 566-3113
FAX (858) 566-6844
Page:
Proj. #:
Date:
Revised:
m e -
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Project:
Designed:
Checked:
^. SIMON WONG ENGINEERING
STRUCTURAL & BRIDGE ENGINEERS
9968 Hibert Street, Suite 202
San Diego, CA 92131
(858) 566-3113
FAX (858) 566-6844
Page:
Proj. #:
Date:
22Z.
Revised:
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Project:
Designed:
Checked:
SIMON WONG ENGINEERING
STRUCTURAL & BRIDGE ENGINEERS
9968 Hibert Street, Suite 202
San Diego, CA 92131
(858) 566-3113
FAX (858) 566-6844
Page: fn9
Proj. #:
Date:
Revised:
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\vy \^ \s, STRUCTURAL & BRIDGE ENGINEERS
L/—=^
Proj. #: ^ _
Designed: ^3T^
9968 Hibert Street, Suite 202 (858) 566-3113
San Diego, CA 92131 FAX (858) 566-6844
Date: , /
Checked: 9968 Hibert Street, Suite 202 (858) 566-3113
San Diego, CA 92131 FAX (858) 566-6844
t-
Revised:
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Appendix F
CRASH WALL REMOVAL CALCULATIONS
Project:
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Page:
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Proj.#: ^
Designed: —r-r^
9968 Hibert Street, Suite 202 (858) 566-3113
San Diego, CA 92131 FAX (858) 566-6844
Date: ,/
//OF
.... ..,.—
Checked:
9968 Hibert Street, Suite 202 (858) 566-3113
San Diego, CA 92131 FAX (858) 566-6844 Revised:
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^ \^ \^ \V STRUCTURAL & BRIDGE ENGINEERS
i—c
Proj. #:
JO- ) - / V/'
Designed: —T-I-.1 r
9968 Hibert Street, Suite 202 (858) 566-3113
San Diego, CA 92131 FAX (858) 566-6844
Date: w dih7
Checked: 9968 Hibert Street, Suite 202 (858) 566-3113
San Diego, CA 92131 FAX (858) 566-6844
—s—
Revised:
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Project:
Designed:
Checked:
^, SIMON WONG ENGINEERING
STRUCTURAL & BRIDGE ENGINEERS
9968 Hibert Street, Suite 202
San Diego, CA 92131
(858) 566-3113
FAX (858) 566-6844
Page:
Proj. #:
Date:
Revised:
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