HINDSIGHT AND FORESIGHT ON THE PERFORMANCE OF PRESTRESSED CONCRETE BRIDGES IN THE SAN FERNANDO EARTHQUAKE

THE 1971 SAN FERNANDO EARTHQUAKE WAS UNUSUAL IN THE MAGNITUDE OF THE VERTICAL MOTION. ONE RESULT OF THIS WAS FAILURE OF BRIDGE COLUMNS IN THE MIDDLE, AS IF CRUSHED RATHER THAN SHEARED. IN GENERAL, BRIDGE FAILURE WAS THE RESULT OF DESTRUCTION OF SUPPORT STRUCTURES AND CONNECTIONS. HINGE AND EXPANSION JOINTS CAME APART, ABUTMENT FILL SETTLEMENT RESULTED IN APPROACHES DROPPING AWAY AND IN FORCES AGAINST THE STRUCTURE ITSELF, PULVERIZATION OF BLOCK FOOTINGS ALLOWED COLUMN BARS TO PULL FREE. SOLUTIONS TO THESE PROBLEMS INCLUDE: STRONGER COLUMN WRAPPING, TIEING OF EXPANSION JOINTS, TOUGHER FOOTINGS, AND BRIDGE DESIGN TO WITHSTAND DYNAMIC STRESSES. BRIDGES CAPABLE OF WITHSTANDING EARTHQUAKES WITHOUT DAMAGE ARE CONSIDERED UNFEASIBLE; RATHER, BRIDGES SHOULD BE DESIGNED TO BE EARTHQUAKE RESISTANT, ELIMINATING THE FATALITIES CAUSED BY COLLAPSE OF THE ENTIRE STRUCTURE.

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Filing Info

  • Accession Number: 00209712
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 28 1972 12:00AM