Research purposes: To analyze the dynamic response characteristics of the RC bridge piers under bi-directional seismic excitation,the bi-directional shaking table test of a RC bridge column was simulated by using the independent developed fiber beam-column numerical analysis platform FENAP, and the simulation result was compared with the experimental test results. Moreover, the time history response of bridge column under unidirectional seismic excitation was also analyzed by using the FENAP and its result was compared with bi-directional results to obtain the dynamic response difference between the two seismic loading conditions.
Research conclusions : (1)The comparison result of numerical simulation by using FENAP with the experiment test of a RC bridge column under bi-directional shaking table test with FENAP and test shows that the FENAP platform can simulate the complicated coupled bi-axial bending moment behaviors of bridge column and predict the amplitude and appearance time of peak displacement on the top of bridge column effectively to get the comparatively accurate numerical results. ( 2 ) Furthermore,the comparison of the time history response of bridge column under unidirectional seismic excitation with bi-directional results shows that the analyzed response displacement of the bridge column subjected to bi-directional excitation is larger than that subjected to unidirectional excitation,while the response acceleration is smaller.(3)The bi-directional coupled effect of RC bridge pier can not be ignored,and the stiffness of column will be overestimated and the response displacement will be underestimated if only one directional seismic response is considered. (4)This research result is available for the seismic design of large span continuous bridge of highway , rail railway and transit.