Abstract
In this study, static cyclic loading tests, uni-directional hybrid tests, uni-directional nolinear seismic simulation using curve approximate hysteretic model developed for steel piers and bi-directional hybrid tests are conducted to clarify the seismic performance of steel bridge piers under bidirectional ground motion excitation. Nine bridge models applying 3 types of bridge pier specimens and 3 ground type conditions are designed based on the current seismic design specification. The response of these bridge models under uni- and bidirectional ground motions are obtained by pseudodanamic tests and numerical simuations. By comparing these tests and simulation results, it is found that the bridge piers could be collapsed under bi-direction ground motions, which are regarded as safe under uni-directional loading. Under the bidirectional seismic action, the capacity of steel piers degrades to averagely 84%, and their response displacement increases 20% more than the values obtained by convential uni-directional loading.