以一座典型的三跨连续梁桥为工程背景,采用Bouc -Wen恢复力模型模拟铅芯橡胶支座(LRB)的力-位移非线性滞回特性,建立了LRB隔震与非隔震连续梁桥有限元模型,编制了运用Runge-Kutta迭代法和Newmark时间积分法联合求解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影响隔震效果的LRB屈服强度与墩、台处LRB的分布等因素进行了分析.分析结果表明:增大LRB的屈服强度,可以显著抑制梁体的位移,但会导致LRB在其它关键部位隔震效果的下降;在桥墩处多布置LRB,会提高桥台剪力隔震率,但会导致LRB在除桥台剪力外的其它关键部位隔震效果的下降.%With typical three-spans continuous girder bridges as the engineering background, the Bouc-Wen model is adopted to simulate the nonlinear hysteric characteristics of force-displacement relationship for LRB and FEA models for isolation and no-isolated continuous girder bridge are established. The time history analysis program is worked out using Runge-Kutta iterative method and Newmark time integration in combination to seek for solution to the nonlinear governing equation of motion of girder bridges. The program in combination with the calculation examples is used to analyze such factors as LRB yield strength and piers, abutment LRB distribution affecting the isolated seismic. The analytic results indicate that an increase in LRB yield strength can obviously control over the girder displacement but lead to a decrease in the isolated seismic effects on the LRB key parts; for this reason, more LRB arranged at the piers can raise the isolated seismic ratio of abutment shear force, but lead to a decrease in the isolated seismic effectiveness in LRB other key parts except for abutment shear force.
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