Although seismic isolation is a well-accepted design strategy for bridges to provide structural earthquake resistance, for bridges with massive piers, it may unexpectedly pose an abnormal influence on the seismic response of bridges due to the effect of substructure mass. This study investigates the effects of bearing friction and pier mass on the seismic performance of bridges isolated by friction pendulum bearings (FPBs). Nonlinear time history analysis is conducted to demonstrate the variation of the bridge peak responses with different bearing frictional coefficients and pier mass. The inherent influential mechanism of the frictional coefficient of FPBs is also discussed in the current study. The results of the analysis show that for FPB-isolated bridges with massive piers, the peak base shear forces of piers first decrease and then increase with the increase of the bearing frictional coefficient. Such a phenomenon may be attributed to the fact that the inertia force of the massive piers will be altered by the variation of bearing friction. The outcome of this study provides a useful reference for practical engineering that the seismic base force of massive bridge piers calculated under a specified bearing frictional coefficient may be smaller than the actual response and cause reduced safety to bridges.

虽然隔震是一种广为接受的桥梁设计策略，以提供结构抗震能力，但对于大型桥墩的桥梁来说，由于下部结构质量的影响，隔震可能会对桥梁的地震响应产生意想不到的异常影响。本研究研究了轴承摩擦力和桥墩质量对摩擦摆轴承 (FPB) 隔震桥梁抗震性能的影响。进行非线性时程分析来证明桥梁峰值响应随不同支座摩擦系数和桥墩质量的变化。本研究还讨论了 FPB 摩擦系数的内在影响机制。分析结果表明，对于大型桥墩FPB隔震桥梁，随着支座摩阻系数的增大，桥墩峰值剪力先减小后增大。造成这种现象的原因可能是大型桥墩的惯性力会因轴承摩擦力的变化而改变。研究结果为实际工程提供了有益的参考：在规定的支座摩擦系数下计算的特大桥梁桥墩地震基础力可能小于实际响应，导致桥梁安全性降低。