AFTER-FRACTURE REDUNDANCY OF TWO-GIRDER BRIDGE: TESTING I-40 BRIDGES OVER RIO GRANDE

The I-40 bridges over the Rio Grande in Albuquerque, New Mexico, were due to be razed in the fall of 1993 because of geometry and traffic safety considerations, thus providing a unique opportunity for testing them. These medium-span steel bridges represent a common design in the United States and are classified by AASHTO as nonredundant "fracture critical" two-girder steel bridges ("fracture critical" classification means that failure of a primary member would probably cause collapse of the bridge). The subject bridge, built in 1963, is 1,275 ft (390 m) long and consists of three medium-span continuous units with spans of 131, 163, and 131 ft (40, 50, and 40 m) each. The bridge was field tested to determine the impact of a near full-depth girder fracture on the redistribution of loads, the load capacity, and the potential for collapse. Four levels of damage were introduced in the middle span of the north plate girder by making various cuts in the web and the flange of the girder. The final cut resulted in a crack 6 ft (1.8 m) deep in the 10-ft (3.1-m)-deep girder, extending from the bottom flange to the floor beam to girder connection. Data were taken under dead load and under a static live load consisting of an 82,000-lb (365,000-N) truck. The fractured bridge proved to be stable, with minimal deflection and no yielding. The after-fracture response and the load redistribution in the fractured bridge were evaluated. The contribution of the various members to the redundancy of the structure was assessed.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 316-326
  • Monograph Title: FOURTH INTERNATIONAL BRIDGE ENGINEERING CONFERENCE, SAN FRANCISCO, CALIFORNIA, AUGUST 28-30, 1995. CONFERENCE PROCEEDINGS, 2 VOLUMES
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00711736
  • Record Type: Publication
  • ISBN: 0309061091
  • Files: TRIS, TRB
  • Created Date: Sep 6 1995 12:00AM