St' Anthony Falls I35W Bridge

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St. Anthony Falls (I-35W) Bridge June 12, 2008
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The former Bridge - 9340

• Opened to traffic in 1967
• Steel truss bridge design
• Concrete deck and pier footings
• Expected life span 50 years
• Fracture critical bridge
• If certain components fail, bridge can fail
• Bridge and Roadway Repair Project Underway at
  time of collapse

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The Collapse

• Bridge Collapsed at 605 p.m. Wednesday, August
  1, 2007
• Plunged nearly 100 vehicles into the Mississippi
  River
• 13 fatalities
• 145 injuries

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Responses after the collapse
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Traffic Management Response
Initial traffic response (first ½ hour) is very
similar to many other major traffic incidents to
which the groups in the RTMC respond frequently

• Deployed 20 changeable message signs activated
  within 3 minutes of collapse
• Continuous coverage on KBEM-FM
• FIRST units provided initial traffic control
• Information provided directly to media and to
  travelers via
• 511 telephone and website
• RTMC traveler Information page

No loss of communications to RTMC due to
redundancy
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Emergency Responders
Minneapolis Incident Command Center at
Minneapolis City Hall
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Metro Transit Response

• Assigned 25 extra buses to north and east metro
  area, results in
• Ridership jumps 25-50
• Advised public to buy bus passes, stagger work
  hours, and carpool
• Free rides from strategic Park-n-Ride Lots
• Began studying additional service enhancements

Park-and-Ride use jumps after I35W bridge collapse
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Traffic Project Framework

• Guidelines for project managers on TR projects
• Must increase capacity, improve safety, and/or
  manage traffic (ITS)
• Must build in a weekend or on weeknights
• No traffic impact for peak periods allowed
• Must be within circle of impact
• Must be let before end of September
• Most must be done by end of August
• Designers have one week from concept to
  construction
• Goal Get traffic back to normal
• Final Tally 30 projects at less then 7M

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Bridge Removal

• Force Account
• Approx. Cost - 7 million
• Coordination with NTSB
• Coordination with Bridge Replacement

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HISTORY OF SITE Date1935
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Bridge Description

• Variable depth superstructure 25 to 11
• Concrete piers supported by footings and drilled
  shafts socketed into rock

330
504
242
147
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Bridge Description

• Two parallel bridges, each with two box girders
• Striped for 5 lanes each direction (10 total)
  with 13 and 14 shoulders (actual design
  loading considers for 7 lanes each direction)
• Future configuration of 4 lanes each direction
  plus light rail line or bus transit lane

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904
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Drilling at Abutment 5on the north side
January 14, 2008
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Aerial view of south side

• January 27, 2008

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Pier 3 construction

• February 20, 2008

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Aerial view of north side

• January 27, 2008

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Pier 2 Mar. 5, 2008
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Erect Temporary Supports

• Phase 6

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Apr. 1, 2008
South side falsework
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South Approach spans May 5, 2008
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Approach span, south side, one box girder Apr.
1, 2008
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Casting Yard, I-35Wsouth side, Washington Avenue
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Casting yard May 5, 2008
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Pre-cast segments
Apr. 1, 2008
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Erect Cantilevered Main-Span
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Segments on West River ParkwayJune 10, 2008
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Segment storage May 5, 2008
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Victory BridgeMiddlesex County, NJ
First segment, May 25, 2008
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Sagadahoc Bridge, Maine
Flatiron FIGG Maines 1st Design/Build
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June 10, 2008 North side roadwork
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More than 200 people showed up on April 19, 2008
Sidewalk Talks every Saturday
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WEBSITEwww.mndot.gov
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WEBCAM

• www.mndot.gov

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Questions?