Bay bridge second cr vassil final

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Bay bridge second cr vassil final

  1. 1. SAN FRANCISCO – OAKLANDBAY BRIDGE SECOND CROSSINGRonald F. Middlebrook, S.E.Roumen V. Mladjov, S.E.Louie International, San Francisco, California, USAInternational IABSE Conference, Rotterdam May 6 - 8, 2013Assessment, Upgrading and Refurbishment of Infrastructures
  2. 2. REUSE THE EAST BAY BRIDGEReuse the abandoned East Crossing structure for theEast Crossing portion of the new Second Bay Bridge2SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USAUse 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 mspan, tower to tower- Longest bridge in the world at timeof completion, 7,1 km- Construction 3 ½ years; 1933 – 1936- Seismic-Safety East Crossing, bythe 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. 4San FranciscoYBIOaklandThe 1936 SFO Bay Bridge + 2013 Safety ProjectSan 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. 5The 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 161tons- 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 tonsOriginal 1936 SFO Bay Bridge StructureSFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  6. 6. 6SFO Bay Bridge Traffic Lanes 1936 - 2013+SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USAThe original Bay Bridge had from 1936 to 1964 – 6 narrowlanes on the upper deck and 3 –truck lanes plus 2 – lightrail lanes on the lower deck.The current Bay Bridge has 5 traffic lanes onboth the upper and lower decks
  7. 7. 7The SFO Bay Bridge is listed in the NationalRegister of Historic Places (NRHP)The National Register calls the Bay Bridge:“ One of the largest and most importanthistoric bridges in the country”.Former President Herbert Hoover at hisground-breaking ceremony: “This marks thephysical beginning of the greatest bridge yeterected by the human race”SFO Bay Bridge an Historical StructureSFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  8. 8. 8Loma Prieta Earthquake, 1989Partial Earthquake DamageSFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USAThe East Span suffered localdamage. One edge of a 15 msection collapsed and droppedonto the lower deck. Thisdamage triggered extensivestudies on the existing structureand its foundations and resultedin a 12 year constructionSeismic Safety project.
  9. 9. 9EAST CROSSING: SKYWAY + SUSPENSION BRIDGE, 2013 ?T.Y. Lin International, Moffat & Nichol Engineers, WeidlingerAssociates, Donald MacDonald ArchitectsTotal Length 3,513 m, Cost $6,45 BillionEast Crossing B.B. - Seismic Safety ProjectSkyway, Multiple Spans 160 m SAS, Span 386 mSFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  10. 10. 10Bridge Element Original Bridge Replacement BridgeTotal Length (meters) 3 377 3 513Main Span (meters) 427 385Secondary Spans (meters) 155 160Traffic Lanes 10 10Vehicles per Day 280 000 300 000 +?Construction Time (years) 3.5 12 ?Completed/Estimated 1936 2013Steel (kg/m2) 416 1843Cost USD 78 M (non comparable) 6450 MBay Bridge East Span ReplacementEAST SPAN REPLACEMENT 77 YEARS LATERSFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  11. 11. 11Traffic Capacity:5 lanes Eastbound from San Francisco to Oakland5 lanes Westbound from Oakland to San FranciscoThe traffic capacity remains the same from1964 to 2012 and will not change in 2013when the replacement of the East Crossingis put into service.The average daily traffic reached 280,000 vehiclesin the early 1990’s and was already creating heavycongestions.Bay Bridge’s Insufficient Traffic CapacitySFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  12. 12. 12Insufficient traffic capacity of the SFO Bay Bridge will notimprove after the Seismic-Safety replacement of the EastCrossing is completed in late 2013. The situation will only getworse with the continuing increase of the Bay Area population.Considering the possible options – the best one is to build a newSecond Bay Bridge along side the original structureA Solution for Bay Bridge Traffic ProblemSFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  13. 13. 13Bay Bridge Second Crossing AlignmentProposed Second Crossing AlignmentSFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  14. 14. 14This new bridge should be a highly efficient bridge, designed and built tothe best standards of today’s sophisticated bridge engineeringcommunity.The direction is given by David P. Billington, Professor atPrinceton 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 allother factors the same”SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USASelecting a Bridge Type for the Second Crossing
  15. 15. What are the possible structural systems for the newWest Crossing? Suspension, cable-stayed, or a combination of the two.760740 740760740 74015SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USASelecting a Bridge Type for the Second Crossing
  16. 16. What are the possible structural systems for thenew East Crossing?Selecting a Bridge Type for the Second CrossingThe best solution for the Second East Crossing is to buildfoundations on a new alignment alongside the existing bridgeand to rebuild onto these foundations the existing 1936 bridgein large portions using powerful jacks and temporary piersinstalled on barges.16SFO Bay Bridge Second Crossing. Ronald F. Middlebrook & Roumen V. Mladjov, Louie Intl, San Francisco, CA, USA
  17. 17. SAN FRANCISCO – OAKLANDBAY BRIDGE SECOND CROSSINGFOR MORE INFORMATION, PLEASE SEE THEWEB-PAGE “SAVE THE BAY BRIDGE”www.SavetheBayBridge.comEMAIL YOUR COMMENTS, QUESTIONS OR SUGGESTIONS TO:Ronald Middlebrook at ronfranco@gmail.comRoumen Mladjov at rmladjov@louieintl.comInternational IABSE Conference, Rotterdam May 6 - 8, 2013Assessment, Upgrading and Refurbishment of Infrastructures

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