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为了探讨桥梁自振特性与地震波频谱特性对LRB隔震效果的影响,以典型三跨连续梁桥为工程背景,采用Bouc-Wen恢复力模型模拟LRB非线性滞回特性,采用Takeda三线性模型模拟桥墩非线性特性,编制了运用Newmark时间积分法和四阶显式Runge-Kutta迭代法联合求解增量形式的全桥非线性运动方程的时程分析程序。利用程序并结合算例对LRB隔震连续梁桥在不同地震激励和不同基本周期影响下的隔震效果进行了分析。结果表明,桥梁结构基本周期和地震激励频谱成分对LRB的隔震效果有较大影响;在易发生低频脉冲型地震波的场地上不宜使用LRB作为桥梁的隔震设备。
In order to investigate the effect of bridge natural vibration characteristics and the spectral characteristics of seismic wave on the isolation effect of LRB, the nonlinear three-span continuous girder bridges with Bouc-Wen restoration model are used to simulate the nonlinear hysteresis characteristics of LRB. Takeda tri-linear model is used to simulate The nonlinear characteristic of bridge piers is studied. A time-history analysis program combining the Newmark time integration method and the fourth-order explicit Runge-Kutta iteration method to solve nonlinear equations of motion is proposed. The program and the example are used to analyze the isolation effect of LRB isolated continuous girder bridges under the influence of different earthquake excitation and different basic periods. The results show that the basic structure of the bridge structure and the seismic excitation spectrum have a great influence on the isolation effect of LRB. LRB should not be used as the isolation equipment of the bridge in the site prone to low frequency impulsive seismic waves.