San Francisco-Oakland Bay Bridge East Span Seismic Safety Project Contractor Information Meeting Construction Contract F4 November 30, 2005
SFOBB East Span Seismic Safety Project 2 Jon Tapping Interim SFOBB East Span Project Manager, Caltrans
SFOBB East Span Seismic Safety Project 3 Dan McElhinney, District 4 Director, Caltrans
SFOBB East Span Seismic Safety Project 4 DVBE - Civil Rights Robert Padilla Statewide Small Business Liaison for Caltrans, Office of Civil Rights Disabled Veteran Business Enterprise (DVBE) goal Disabled Veteran Business Enterprise (DVBE) goal Prime Contractor’s commitment Prime Contractor’s commitment
SFOBB East Span Seismic Safety Project 5 Technical Issues Brian Maroney SFOBB East Span Technical Manager, Caltrans
SFOBB East Span Seismic Safety Project 6 Guidelines for Q&A Please submit questions in writing on cards provided 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 Any answers provided today are preliminary and not considered final until posted on the bidder inquiry web site Bidder Inquiry website: Future inquiries may be addressed to the Duty Senior Mailing address: P.O. Box 23660, Oakland, CA Fax number: (510) All inquiries must include the contract number ( f4)
SFOBB East Span Seismic Safety Project 7 Mike Whiteside Upcoming Addenda
SFOBB East Span Seismic Safety Project 8 Upcoming Addendum Items Addendum 4, early December CJP to PJP CJP to PJP Remove “Unsatisfactory Progress” Specification Remove “Unsatisfactory Progress” Specification Add Temp. Tower AE & AW final Designs Add Temp. Tower AE & AW final Designs Use of Electorslag Welding Use of Electorslag Welding Pre-Assembly Requirements Reduced Pre-Assembly Requirements Reduced Constructability Refinements/Improvements & Conflict Resolution Constructability Refinements/Improvements & Conflict Resolution
SFOBB East Span Seismic Safety Project 9 Upcoming Addendum Items Addendum 5, late December Performance specifications for castings E2 Shear Key/Bearing Alternative E2 Shear Key/Bearing Alternative Hinge K Pipe Beam Fabrication Hinge K Pipe Beam Fabrication Hinge K Closure Hinge K Closure Availability of North Side of Oakland Approach Availability of North Side of Oakland Approach
SFOBB East Span Seismic Safety Project 10 Upcoming Addendum Items Addendum 6, early January Miscellaneous clean-up issues Miscellaneous clean-up issues Constructability Refinements/Improvements & Conflict Resolution Constructability Refinements/Improvements & Conflict Resolution
SFOBB East Span Seismic Safety Project 11 Michael Stone Schedule
SFOBB East Span Seismic Safety Project 12 SAS Schedule
SFOBB East Span Seismic Safety Project 13 SAS Schedule – Working Drawings
SFOBB East Span Seismic Safety Project 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
SFOBB East Span Seismic Safety Project 15 Marwan Nader Temporary Tower Design Example
SFOBB East Span Seismic Safety Project 16 TEMPORARY TOWER DESIGN EXAMPLE November 18, 2005
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SFOBB East Span Seismic Safety Project 18 Tower Configurations Tower C Tower C Tower G Tower G
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SFOBB East Span Seismic Safety Project 21 DESIGN CRITERIA Codes, Standards, Specifications Applicable Codes/Specifications: CalTrans Standard Specifications, 1999 CalTrans Standard Specifications, 1999 CalTrans Special Provisions, Contract F4 CalTrans Special Provisions, Contract F4 CalTrans Falsework Manual, Rev. 32, November 2001 CalTrans Falsework Manual, Rev. 32, November 2001 AISC-LRFD, 1999 for rolled sections AISC-LRFD, 1999 for rolled sections API RP2A-LRFD, July 1993 for tubular sections and connections (and pipe piles) API RP2A-LRFD, July 1993 for tubular sections and connections (and pipe piles) AASHTO-LRFD Bridge Construction Specification, 2nd Ed. (Concrete only) AASHTO-LRFD Bridge Construction Specification, 2nd Ed. (Concrete only) ANSI/ASCE 795 (Wind loads only) ANSI/ASCE 795 (Wind loads only)
SFOBB East Span Seismic Safety Project 22 Independent Loads Cases Dead Load Dead Load Live Load Live Load Vessel Impact Vessel Impact Earthquake Earthquake 1.0X-direction Y direction 0.3 X-direction Y direction -1.0 X-direction Y direction 0.3 X-direction Y direction Wind Load Wind Load Wind, Wave and Current Wind, Wave and Current
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SFOBB East Span Seismic Safety Project 26 Wind, Wave and Current Wind Wind ASCE 7-95 specifies an 85MPH Wind +10m Section of the Special Provisions specifies a 100 MPH 3-sec 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 Wave 2m high, 6sec wave per revised Special Provisions Drag and inertia coefficients are 0.65 and 1.6 (ref API RP2A), respectively Current 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.
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SFOBB East Span Seismic Safety Project 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)
SFOBB East Span Seismic Safety Project 29 Load Combinations 1.4 DL 1.1 DL LL 1.0 DL LL Wind Current Impact (Vessel) 1.0 DL LL EQ 1.0 DL LL +1.3Wind +1.3Wave + 1.3Current
SFOBB East Span Seismic Safety Project 30 Tower C Tubular steel structure, trucked and assembled on site with the use of a crawler crane Tubular steel structure, trucked and assembled on site with the use of a crawler crane All tower and truss joints are to be bolted All tower and truss joints are to be bolted Leg segments bolted together with splice flanges located near inflection points 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 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 Gusset plates actually penetrate through the legs to provide load continuity through the joints
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SFOBB East Span Seismic Safety Project 34 Tower G 6- leg tubular steel jacket structure, 65m (213 ft) high 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 14m x 30m (46 ft x 98 ft) footprint at the top, to match bearing locations Pin piles driven through the jacket legs Pin piles driven through the jacket legs The jacket base plan dimensions provide the same overturning resistance in both orthogonal directions The jacket base plan dimensions provide the same overturning resistance in both orthogonal directions Bay height chosen to provide efficient diagonal bracing Bay height chosen to provide efficient diagonal bracing Cross braced to provide ductility Cross braced to provide ductility
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SFOBB East Span Seismic Safety Project 39 3D View of Towers ABC Model
SFOBB East Span Seismic Safety Project 40 Mode 1 (T=0.78 sec)
SFOBB East Span Seismic Safety Project 41 Y Spectral Displacement (5.62 cm at top of Tower C) (Transverse)
SFOBB East Span Seismic Safety Project 42 Wind Displacement (0.8 cm at top of Tower C)
SFOBB East Span Seismic Safety Project 43 Transverse Pushover at 115mm
SFOBB East Span Seismic Safety Project 44 Shear reductions are due to compression member buckling (tension members take over) Transverse Pushover to 115mm
SFOBB East Span Seismic Safety Project 45 3D View of Tower C Model as a separate structure
SFOBB East Span Seismic Safety Project 46 Mode 2 (T=1.43 sec)
SFOBB East Span Seismic Safety Project 47 Y Spectral Displacement (7.63cm at top of Tower) (Transverse)
SFOBB East Span Seismic Safety Project 48 Wind Displacement (1.06cm at top of Tower)
SFOBB East Span Seismic Safety Project 49 Transverse Pushover at 300mm
SFOBB East Span Seismic Safety Project 50 Shear reductions are due to compression member buckling (tension members take over) Transverse Pushover to 300mm, Force- Displacement Curve (76mm Seismic Demand)
SFOBB East Span Seismic Safety Project 51 Tower C Conclusions Combined structure is stiffer; lower period Combined structure is stiffer; lower period Produces larger forces Produces larger forces Separate structure is more flexible; higher period Separate structure is more flexible; higher period Produces lower forces Produces lower forces Consider Base Isolation System Consider Base Isolation System (Slip plane at bearing level with retainers) (Slip plane at bearing level with retainers)
SFOBB East Span Seismic Safety Project 52 3D View of Tower G Model
SFOBB East Span Seismic Safety Project 53 3D View of Tower G alone
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SFOBB East Span Seismic Safety Project 55 Mode 2 (T=1.36 sec)
SFOBB East Span Seismic Safety Project 56 IMPACTY Displacement (Y=4.5 cm at top of tower, Y=11.5 cm at point of impact)
SFOBB East Span Seismic Safety Project 57 Y Spectral Displacement (9.7 cm at top of Tower)
SFOBB East Span Seismic Safety Project 58 Wind Displacement (4.4 cm at top of Tower)
SFOBB East Span Seismic Safety Project 59 Transverse Pushover Displaced Shape at X=0.45 m
SFOBB East Span Seismic Safety Project 60 Transverse Pushover 0 2,000 4,000 6,000 8,000 10,000 12,000 14, Displacement at Top of Tower (m) Base Shear (kN) No member buckling present at this load level – piles govern capacity Transverse Pushover Curve to 0.45 m
SFOBB East Span Seismic Safety Project 61 3D View of Tower G Model Pinned at the Base
SFOBB East Span Seismic Safety Project 62 Transverse Pushover Displaced Shape at X=1.0 m
SFOBB East Span Seismic Safety Project 63 Transverse Pushover 0 5,000 10,000 15,000 20, Displacement at Top of Tower (m) Base Shear (kN) Shear reductions are due to compression member buckling (tension members take over) Transverse Pushover Curve to 1.0 m
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SFOBB East Span Seismic Safety Project 66 Tower G Conclusions Provide Vessel Impact energy absorption system (reduces overall demand on tower) Provide Vessel Impact energy absorption system (reduces overall demand on tower) Increase pile diameter and/or reduce bracing size (to provide more tower ductility) Increase pile diameter and/or reduce bracing size (to provide more tower ductility)
SFOBB East Span Seismic Safety Project 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.
SFOBB East Span Seismic Safety Project 68 Chris Traina Cash Flow Analysis
SFOBB East Span Seismic Safety Project 69 Early Pay Items Analysis
SFOBB East Span Seismic Safety Project 70 Steel Payments
SFOBB East Span Seismic Safety Project 71 Cash Flow Analysis
SFOBB East Span Seismic Safety Project 72 Rick Morrow Outstanding Bidder Inquiries Tower Mock-Up