Effects of seabed ground motion on vulnerability of offshore bridges
WANG Debin1, LI Xin1, SUN Zhiguo2, WANG Dongsheng3, CHEN Baokui4
1.School of Civil Engineering, Dalian Jiaotong University, Dalian 116028, China;
2.School of Civil Engineering, Institute of Disaster Prevention, Beijing 101601, China;
3.School of Civil and Transporting Engineering, Hebei University of Technology, Tianjin 300401, China;
4.School of Architecture Engineering, Nanchang University, Nanchang 330031, China
Abstract：Here, to study seismic performance of bridges under offshore ground motion, taking the approach segment of a certain offshore bridge as an example, its finite element analysis model based on ABAQUS was established.Based on the 1-D wave theory and hydrodynamic equation, the spectral representation method was used to simulate offshore ground motion.The vulnerability of the bridge was analyzed by using the probabilistic seismic demand analysis (PSDA) method, and transcendental probability curves of bridge piers under offshore and onshore ground motions, respectively were drawn and analyzed contrastively.The results showed that compared with onshore ground motion, offshore ground motion can significantly increase the damage probability of piers, and the maximum increase amplitude reaches 23.44%; compared with onshore ground motion, the bridge vulnerable pier column changes under offshore ground motion; the seismic performance study of offshore bridges based on onshore ground motion can underestimate damage of piers and mis-estimate bridge’s vulnerable parts to cause inaccurate calculation results.
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