SEISMIC RESISTANCE OF STEEL BASCULE BRIDGES

This paper presents the seismic vulnerabilities and retrofit strategies of the Third Street Bascule Bridge and reflects on experience obtained from the Badger Avenue Bascule Bridge. The bascule bridge is a very vulnerable bridge type in the event of an earthquake because of the location of its counterweight. The high overturning force due to the massive counterweight or the movable leaf response can cause bridge collapse at the weakest link along its load path (i.e., trunnions, bearings, etc.). The possible failure modes include tower frame yielding or buckling, bearing shear and uplift failure, pier flexural and shear failure, and pile foundation failure. The capacities of structural components were evaluated to identify the weakest link. Proposed retrofit strategies for Third Street Bridge included: strengthening members and connections to carry seismic loads, the relocation of the counterweight to an underground pit, and tower base fusing and isolation.

• Corporate Authors:

  California Department of Transportation

  1120 N Street
  Sacramento, CA  United States  95814
• Authors:
  • Schamber, R A
  • Li, F
  • Fuller, R T
  • Liu, W D
• Conference:
  • Second National Seismic Conference on Bridges and Highways
  • Location: Sacramento, California
  • Date: 1997-7-8 to 1997-7-11
• Publication Date: 1997

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 381-394

Subject/Index Terms

• TRT Terms: Bascule bridges; Bearing capacity; Earthquake resistant design; Retrofitting; Structural members
• Uncontrolled Terms: Failure modes; Seismic vulnerability
• Subject Areas: Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00760111
• Record Type: Publication
• Files: TRIS, STATEDOT
• Created Date: Feb 2 1999 12:00AM