Abstract: In view of the complex seismic response of curved girder bridges caused by plane irregularity, this study investigates the effects of different isolation bearings on seismic response and energy dissipation. Finite element models with Linear Natural Rubber (LNR) bearings were established using ANSYS, and horizontal bi-directional ground motions selected from the code-based response spectrum were applied. Lead Rubber Bearings (LRB) and High Damping Rubber Bearings (HDR) were further analyzed to evaluate their seismic isolation performance. Results show that, compared with LNR bearings, LRB and HDR bearings significantly reduce radial and tangential displacements (by 66.7% and 67.4%, respectively) and exhibit larger cumulative energy dissipation (maximum ratios of 2.26 and 2.13). Both bearings demonstrate good isolation performance and can be selected according to engineering needs. However, under different ground motions, seismic responses and the onset of bearing energy dissipation vary, highlighting the necessity of considering ground motion characteristics in seismic design.

Key words: curved girder bridge, seismic response, seismic-reduction rate, energy dissipation ratio