The objective of this proposal is to evaluate the seismic vulnerability of a bridge through analysis of the entire bridge structure. The data obtained in the 1995 Hyogoken-Nanbu earthquake provide a unique opportunity for researchers to evaluate the performance of bridge structures under severe earthquake loads and to advance the state-of-the-art analysis methods for reinforced concrete bridges. In pursuit of this objective , a joint U.S.-Japan-Europe research program is formulated. The research tasks are (1) development of viable analysis techniques for assessing the seismic vulnerability of bridge structures; (2) investigation of the cause of failure of a selected reinforced concrete bridge in the Hyogoken-Nanbu earthquake; (3) evaluation of the performance of reinforced concrete bridges which reflect the current and older designs in the respective countries under the strong ground motions recorded in the Hyogoken-Nanbu earthquake; and (4) comparison of bridge designs in the respective countries. To this end, systematic analyses will be carried out at the local pier level as well as at the system level for several bridge structures. The study will be carried out in a complementary and yet independent manner by each group. This study will result in a better understanding of the behavior of reinforced concrete highway bridge systems under strong earthquake ground motions, and will provide viable analysis methods which can be used to evaluate the local as well as global performance of bridge structures. These analysis tools can be used to evaluate the seismic vulnerability of bridge structures in a rational and definitive manner, and, in the future, to evaluate the efficiencies of various seismic retrofit techniques. The lessons learned from the Hyogoken-Nanbu earthquake and the comparison of different design practices will provide information that can be used to further improve design provisions on bridges.
