Performance of Reinforced Concrete Bridge Piers During the 1995 Hyogoken-Nanbu Earthquake

本提案的目的是通过对整个桥梁结构的分析来评估桥梁的地震易损性。1995年小古根-南部地震中获得的数据为研究人员提供了一个独特的机会来评估桥梁结构在强烈地震荷载下的性能，并推动了钢筋混凝土桥梁的最新分析方法。为实现这一目标，美国、日本、欧洲制定了一个联合研究项目。研究任务是：(1)开发可行的桥梁结构地震易损性评估分析技术；(2)小谷肯-南部地震中某钢筋混凝土桥梁的破坏原因分析；(3)在小古肯-南部地震中记录的强地面运动下，对各国反映当前和旧设计的钢筋混凝土桥梁的性能进行了评价；(4)各国桥梁设计比较。为此，将对若干桥梁结构进行局部墩级和系统级的系统分析。该研究将由每个小组以互补但独立的方式进行。本研究将有助于更好地了解强震作用下钢筋混凝土公路桥梁体系的性能，并将提供可行的分析方法，可用于评估桥梁结构的局部和整体性能。这些分析工具可用于以合理和明确的方式评估桥梁结构的地震易损性，并在未来评估各种抗震改造技术的效率。从小古根-南部地震中吸取的教训和不同设计实践的比较将提供可用于进一步改进桥梁设计规定的信息。

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.