近场简支梁铅芯橡胶支座隔震特性分析

Isolation Characteristic Analysis of Simple Supported Bridge to Near Fault Ground Motions

随着公路桥梁的建设和隔震技术的发展,近断层隔震桥梁的抗震性能研究十分必要.以一座简支微弯梁桥为例,通过非线性时程的方法,探讨简支梁桥在近场地震作用下桥梁的减隔震特性及参数变化规律.分析结果表明,该隔震简支梁桥在近场地震作用下,墩底弯矩和支座位移比远场地震作用下大;采用隔震技术后,在近场地震作用下,减震效果仍有效;纵横向支座位移随屈服强度的增加而减小,且均有随初始刚度增加而减小的趋势;墩底弯矩因波脉冲不同和各墩刚度不一,随初始刚度和屈服强度的变化不一.

Based on the nonlinear dynamic time history analysis,a slightly curved simple supported isolated bridge is studies, to investigate the characteristic and the rule of parameters of the lead rubber bearing （LRB）. Results show that the moment at the bottom of piers and the displacements of LRB to near fault earthquake ground motions are larger than those to far fault earthquake ground motions. It is efficient to reduce the response of isolated bridge to the near fault earthquake ground motions by isolation technology. The bearing displacement decreases with the increment of the initial stiffness and the yielding strength, while the moment at the bottom of the pier varies with the change of the different stiffness and pulse types