Environmental Groups

1
San Francisco-Oakland Bay BridgeEast Span
Seismic Safety Project Contractor
Information Meeting Construction Contract
04-0120F4 November 30, 2005
2

• Jon Tapping
• Interim SFOBB East Span
• Project Manager, Caltrans

3

• Dan McElhinney,
• District 4 Director, Caltrans

4
DVBE - Civil Rights

• Robert Padilla
• Statewide Small Business Liaison for Caltrans,
  Office of Civil Rights
• Disabled Veteran Business Enterprise (DVBE) goal
• Prime Contractors commitment

5
Technical Issues

• Brian Maroney
• SFOBB East Span Technical Manager, Caltrans

6
Guidelines for QA

• Please submit questions in writing on cards
  provided
• Any answers provided today are preliminary and
  not considered final until posted on the bidder
  inquiry web site
• Bidder Inquiry website http//www.dot.ca.gov/d
  ist4/construction/Inquiries/04-0120F4_inquiry.html
  
• Future inquiries may be addressed to the Duty
  Senior
• email Duty_Senior_District04_at_dot.ca.gov
• Mailing address P.O. Box 23660, Oakland, CA
  94623-0660
• Fax number [phone]
• All inquiries must include the contract number
  (04-0120f4)

7

• Mike Whiteside
• Upcoming Addenda

8
Upcoming Addendum Items

• Addendum 4, early December
• CJP to PJP
• Remove Unsatisfactory Progress Specification
• Add Temp. Tower AE AW final Designs
• Use of Electorslag Welding
• Pre-Assembly Requirements Reduced
• Constructability Refinements/Improvements
  Conflict Resolution

9
Upcoming Addendum Items

• Addendum 5, late December
• Performance specifications for castings
• E2 Shear Key/Bearing Alternative
• Hinge K Pipe Beam Fabrication
• Hinge K Closure
• Availability of North Side of Oakland Approach

10
Upcoming Addendum Items

• Addendum 6, early January
• Miscellaneous clean-up issues
• Constructability Refinements/Improvements
  Conflict Resolution

11

• Michael Stone
• Schedule

12
SAS Schedule
13
SAS Schedule Working Drawings
14
SAS Schedule

• Changes since last advertisement
• Increased bidder compensation
• Revised CRIP specifications to provide
  non-compensable time for CRIP submittal
• Reduction in time required for Caltrans to review
  and approve weld repairs
• Allowing repairs to be made after erection
• E2/T1 availability earlier in the contract, more
  time between E2/T1 availability and Milestones 2,
  3 and 4

15

• Marwan Nader
• Temporary Tower Design Example

16
TEMPORARY TOWER DESIGN EXAMPLE

• November 18, 2005

17
(No Transcript)
18
Tower Configurations

• Tower C
• Tower G

19
(No Transcript)
20
(No Transcript)
21
DESIGN CRITERIACodes, Standards, Specifications

• Applicable Codes/Specifications
• CalTrans Standard Specifications, 1999
• CalTrans Special Provisions, Contract 040120F4
• CalTrans Falsework Manual, Rev. 32, November 2001
• AISC-LRFD, 1999 for rolled sections
• API RP2A-LRFD, July 1993 for tubular sections and
  connections (and pipe piles)
• AASHTO-LRFD Bridge Construction Specification,
  2nd Ed. (Concrete only)
• ANSI/ASCE 795 (Wind loads only)

22
Independent Loads Cases

• Dead Load
• Live Load
• Vessel Impact
• Earthquake
• 1.0X-direction 0.3 Y direction
• 0.3 X-direction 1.0 Y direction
• -1.0 X-direction 0.3 Y direction
• 0.3 X-direction - 1.0 Y direction
• Wind Load
• Wind, Wave and Current

23
(No Transcript)
24
(No Transcript)
25
(No Transcript)
26
Wind, Wave and Current

• Wind
• ASCE 7-95 specifies an 85MPH Wind Gust _at_ 10m
• Section 10-1.59 of the Special Provisions
  specifies a 100 MPH 3-sec gust _at_ El. 50m.
• The 100MPH Wind Gust velocity stated in the
  Special Provisions govern.
• The importance factor is 1.15 per revised Special
  Provisions
• The exposure coefficients are for exposure D
  (open water)
• The gust factor is 0.85 in accordance with ASCE
  Section 6.6
• The shape factor on projected flat surface of the
  box girder was 1.5 (ASCE Table 6-8), and 0.8 for
  the tubular tower structures (ASCE Table 6-9).
• Wave
• 2m high, 6sec wave per revised Special Provisions
• Drag and inertia coefficients are 0.65 and 1.6
  (ref API RP2A), respectively
• Current
• 3-knot surface current was conservatively
  assumed(Note Vessel Collision Report indicates
  a uniform 2 knot design current for Impact
  design).
• The surface current velocity profile with depth
  was developed utilizing a 1/7th power
  distribution.

27
(No Transcript)
28
Construction Loads/Stages

• 1. Individual deck lifts 1 thru 9 on the
  appropriate towers
• 2. In- fill / heavy lifts 1, 2, 3 4 on the
  appropriate towers
• 3. Connecting the deck sections together in the
  longitudinal direction
• 4. Connecting the cross beams in the transverse
  direction
• 5. Connecting the deck sections to W2 and E2 cap
  beams
• Tower C
• Temporary Tower (TT)
• TT plus Deck Lift 1 (830 Tonnes) on 4 bearing
  pads
• TT plus Deck Lift 4 (459 Tonnes) on 4 bearing
  pads
• TT plus Deck Lift 4 plus half of Heavy Lift 1
  (830/2 415 Tonnes) total 875 T
• Envelope of Vertical Forces (see Table 1 on Sheet
  Construction Load No. 1)
• Tower G
• Temporary Tower (TT)
• TT plus Deck Lift 9 (892 Tonnes) on 6 bearing
  pads
• TT plus Deck Lift 9 plus half of Heavy Lift 3
  (1285/2 643 Tonnes) tot al 1535 T
• TT plus Deck Lift 9 plus half of Heavy Lifts 3
  4 2177 T
• Envelope of Vertical Forces (see Table 1 on Sheet
  Construction Load No. 1)

29
Load Combinations

• 1.4 DL
• 1.1 DL 1.3 LL
• 1.0 DL 1.0 LL 0.5 Wind 1.0 Current 1.0
  Impact (Vessel)
• 1.0 DL 1.0 LL 1.0 EQ
• 1.0 DL 1.0 LL 1.3Wind 1.3Wave 1.3Current

30
Tower C

• Tubular steel structure, trucked and assembled on
  site with the use of a crawler crane
• All tower and truss joints are to be bolted
• Leg segments bolted together with splice flanges
  located near inflection points
• Pre-installed gusset plates welded to legs for
  bracing members to be bolted onto
• Gusset plates actually penetrate through the legs
  to provide load continuity through the joints

31
(No Transcript)
32
(No Transcript)
33
(No Transcript)
34
Tower G

• 6- leg tubular steel jacket structure, 65m (213
  ft) high
• 14m x 30m (46 ft x 98 ft) footprint at the top,
  to match bearing locations
• Pin piles driven through the jacket legs
• The jacket base plan dimensions provide the same
  overturning resistance in both orthogonal
  directions
• Bay height chosen to provide efficient diagonal
  bracing
• Cross braced to provide ductility

35
(No Transcript)
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
3D View of Towers ABC Model
40
Mode 1 (T0.78 sec)
41
Y Spectral Displacement (5.62 cm at top of Tower
C) (Transverse)

42
Wind Displacement (0.8 cm at top of Tower C)
43
Transverse Pushover at 115mm
44
Transverse Pushover to 115mm
Shear reductions are due to compression member
buckling (tension members take over)
45
3D View of Tower C Model as a separate structure
46
Mode 2 (T1.43 sec)
47
Y Spectral Displacement (7.63cm at top of Tower)
(Transverse)


48
Wind Displacement (1.06cm at top of Tower)
49
Transverse Pushover at 300mm
50
Transverse Pushover to 300mm, Force-Displacement
Curve (76mm Seismic Demand)


Shear reductions are due to compression member
buckling (tension members take over)
51
Tower C Conclusions

• Combined structure is stiffer lower period
• Produces larger forces
• Separate structure is more flexible higher
  period
• Produces lower forces
• Consider Base Isolation System
• (Slip plane at bearing level with retainers)

52
3D View of Tower G Model

53
3D View of Tower G alone
54
(No Transcript)
55
Mode 2 (T1.36 sec)


56
IMPACTY Displacement (Y4.5 cm at top of tower,
Y11.5 cm at point of impact)


57
Y Spectral Displacement (9.7 cm at top of Tower)


58
Wind Displacement (4.4 cm at top of Tower)


59
Transverse Pushover Displaced Shape at X0.45 m


60
Transverse Pushover Curve to 0.45 m
No member buckling present at this load level
piles govern capacity
61
3D View of Tower G Model Pinned at the Base


62
Transverse Pushover Displaced Shape at X1.0 m


63
Transverse Pushover Curve to 1.0 m


Shear reductions are due to compression member
buckling (tension members take over)
64
(No Transcript)
65
(No Transcript)
66
Tower G Conclusions

• Provide Vessel Impact energy absorption
  system(reduces overall demand on tower)
• Increase pile diameter and/or reduce bracing size
  (to provide more tower ductility)

67
It should be noted that this Design Example is a
first iteration in the design process and
requires further refining in order to meet the
full intent of the specified design requirements.

• As noted, there are several approaches to meet
  the requirements of the Drawings and Special
  Provisions.

68

• Chris Traina
• Cash Flow Analysis

69
Early Pay Items Analysis
70
Steel Payments
71
Cash Flow Analysis
72

• Rick Morrow
• Outstanding Bidder Inquiries
• Tower Mock-Up