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Bay bridge second cr vassil final

  1. 1. SAN FRANCISCO – OAKLAND BAY BRIDGE SECOND CROSSING Ronald F. Middlebrook, S.E. Roumen V. Mladjov, S.E. Louie International, San Francisco, California, USA International IABSE Conference, Rotterdam May 6 - 8, 2013 Assessment, Upgrading and Refurbishment of Infrastructures
  2. 2. REUSE THE EAST BAY BRIDGE Reuse the abandoned East Crossing structure for the East Crossing portion of the new Second Bay Bridge 2SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA Use the abandoned East Crossing Structure for the East Portion of a New Second Bay Bridge
  3. 3. 3 - Ralph Modjeski et al - Suspension Spans – 704 m - Cantilever truss – 427 m span, tower to tower - Longest bridge in the world at time of completion, 7,1 km - Construction 3 ½ years; 1933 – 1936 - Seismic-Safety East Crossing, by the end of 2013? THE ORIGINAL SFO BAY BRIDGE (1936) SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  4. 4. 4 San Francisco YBI Oakland The 1936 SFO Bay Bridge + 2013 Safety Project San Francisco – Oakland Bay Original Bridge (1936) and the East Bay Seismic Safety Project (2013?) SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  5. 5. 5 The 1936 SFO Bay Bridge: - West Crossing - San Francisco to YBI twin suspension bridges; 3 140 m, with two main spans 704 m Steel Structures used 97 161 tons - YBI segment – tunnel and short viaduct - East Crossing - YBI to Oakland 3 377 m, including: 4 - 88 m steel truss spans + 738 m cantilever truss structure + 5 - 155 m through-truss spans + 14 - 88 m deck-truss spans Steel Structures used 54 432 tons -Total Steel structures used 151 593 tons Original 1936 SFO Bay Bridge Structure SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  6. 6. 6 SFO Bay Bridge Traffic Lanes 1936 - 2013+ SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA The original Bay Bridge had from 1936 to 1964 – 6 narrow lanes on the upper deck and 3 –truck lanes plus 2 – light rail lanes on the lower deck. The current Bay Bridge has 5 traffic lanes on both the upper and lower decks
  7. 7. 7 The SFO Bay Bridge is listed in the National Register of Historic Places (NRHP) The National Register calls the Bay Bridge: “ One of the largest and most important historic bridges in the country”. Former President Herbert Hoover at his ground-breaking ceremony: “This marks the physical beginning of the greatest bridge yet erected by the human race” SFO Bay Bridge an Historical Structure SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  8. 8. 8 Loma Prieta Earthquake, 1989 Partial Earthquake Damage SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA The East Span suffered local damage. One edge of a 15 m section collapsed and dropped onto the lower deck. This damage triggered extensive studies on the existing structure and its foundations and resulted in a 12 year construction Seismic Safety project.
  9. 9. 9 EAST CROSSING: SKYWAY + SUSPENSION BRIDGE, 2013 ? T.Y. Lin International, Moffat & Nichol Engineers, Weidlinger Associates, Donald MacDonald Architects Total Length 3,513 m, Cost $6,45 Billion East Crossing B.B. - Seismic Safety Project Skyway, Multiple Spans 160 m SAS, Span 386 m SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  10. 10. 10 Bridge Element Original Bridge Replacement Bridge Total Length (meters) 3 377 3 513 Main Span (meters) 427 385 Secondary Spans (meters) 155 160 Traffic Lanes 10 10 Vehicles per Day 280 000 300 000 +? Construction Time (years) 3.5 12 ? Completed/Estimated 1936 2013 Steel (kg/m2) 416 1843 Cost USD 78 M (non comparable) 6450 M Bay Bridge East Span Replacement EAST SPAN REPLACEMENT 77 YEARS LATER SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  11. 11. 11 Traffic Capacity: 5 lanes Eastbound from San Francisco to Oakland 5 lanes Westbound from Oakland to San Francisco The traffic capacity remains the same from 1964 to 2012 and will not change in 2013 when the replacement of the East Crossing is put into service. The average daily traffic reached 280,000 vehicles in the early 1990’s and was already creating heavy congestions. Bay Bridge’s Insufficient Traffic Capacity SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  12. 12. 12 Insufficient traffic capacity of the SFO Bay Bridge will not improve after the Seismic-Safety replacement of the East Crossing is completed in late 2013. The situation will only get worse with the continuing increase of the Bay Area population. Considering the possible options – the best one is to build a new Second Bay Bridge along side the original structure A Solution for Bay Bridge Traffic Problem SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  13. 13. 13 Bay Bridge Second Crossing Alignment Proposed Second Crossing Alignment SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  14. 14. 14 This new bridge should be a highly efficient bridge, designed and built to the best standards of today’s sophisticated bridge engineering community. The direction is given by David P. Billington, Professor at Princeton University in Civil Engineering, March 1990: “There are three principles of good bridge design: • Efficiency (materials) • Economy (cost and time) • Elegance (slenderness)… The least expensive bridge is the best bridge with all other factors the same” SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA Selecting a Bridge Type for the Second Crossing
  15. 15. What are the possible structural systems for the new West Crossing? Suspension, cable- stayed, or a combination of the two. 760740 740 760740 740 15SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA Selecting a Bridge Type for the Second Crossing
  16. 16. What are the possible structural systems for the new East Crossing? Selecting a Bridge Type for the Second Crossing The best solution for the Second East Crossing is to build foundations on a new alignment alongside the existing bridge and to rebuild onto these foundations the existing 1936 bridge in large portions using powerful jacks and temporary piers installed on barges. 16SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  17. 17. SAN FRANCISCO – OAKLAND BAY BRIDGE SECOND CROSSING FOR MORE INFORMATION, PLEASE SEE THE WEB-PAGE “SAVE THE BAY BRIDGE” www.SavetheBayBridge.com EMAIL YOUR COMMENTS, QUESTIONS OR SUGGESTIONS TO: Ronald Middlebrook at ronfranco@gmail.com Roumen Mladjov at rmladjov@louieintl.com International IABSE Conference, Rotterdam May 6 - 8, 2013 Assessment, Upgrading and Refurbishment of Infrastructures

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