Seismic response of long multiple‐span highway bridges

Non-linear seismic responses are described for three prototype, long, multiple-span, reinforced concrete, modern highway bridge structures, namely the 5/14 South Connector Overcrossing and the curved Figueroa Street Under-crossing as designed by the California Department of Transportation, and a straight version of the Figueroa Street Undercrossing. The analytical seismic responses are discussed and are correlated with the apparent prototype behaviour experienced during the San Fernando, California, earthquake of 9 February 1971. In particular, the causes of collapse of the 5/14 South Connector Overcrossing are identified and examined. Finally, based on parameter studies of the seismic responses of these structures, general conclusions and recommendations related to seismic design methodology are presented.