FPS 隔震简支梁桥近断层地震响应研究

摘要

To examine the application effect of Friction Pendulum System (FPS) bearings in bridge structures under the action of near-fault earthquakes ,the three-dimensional finite element analytical model of a one-span simply-supported railway bridge with FPS bearings was established . The records of nine typical near-fault earthquakes were taken as excitors ,the non-linear time-his-tory analytical method was used to calculate the seismic response in the longitudinal bridge direc -tion ,and the results were contrastively analyzed .The results of the study indicate that under the action of near-fault earthquakes ,FPS bearings are able to mitigate the earthquake energy to a cer-tain extent ,and under most circumstances ,the increase of the equivalent curvature radius of FPS bearings leads to the enhancement of the seismic mitigation effect ,which is similar to the effect un-der the action of non-near-fault earthquakes .However ,only using FPS bearings can not satisfy the anti-seismic requirements of the bridge structure under certain circumstances .Thus ,it is necessary to take other seismic mitigation and isolation measures to assist the FPS bearings so as to assure the bridge structure safety .%为研究近断层地震作用下摩擦摆支座（FPS）在桥梁结构中的使用效果，建立了一跨 FPS 隔震铁路简支梁桥的三维有限元分析模型，以9条典型近断层地震记录作为激励，采用非线性时程分析方法对其顺桥向地震响应进行计算，并对结果进行对比分析。研究结果表明：在近断层地震作用下，FPS 支座可以发挥一定的隔震作用，且大部分情况下，增大 FPS 支座等效曲率半径可提高其隔震效率，这与非近断层地震作用下的情况相同，但仅使用 FPS 支座进行隔震设计有时并不足以满足桥梁结构的抗震能力要求，需要采取其它必要的抗震、减隔震措施与 FPS 支座共同工作，以保证桥梁结构安全。