基础非线性对桥墩地震反应的影响

在桩基础桥墩滞回特性的模型试验基础上,提出了用Clough模型模拟基础(地基)的恢复力特性。桥墩采用Takeda恢复力模型。用强震记录与人工合成地震动作为输入对铁路简支梁桥进行了非线性地震反应分析,讨论了不同地震动输入及不同地震强度时基础非线性对桥梁地震反应的影响。研究结果表明,考虑基础的非线性一般会使墩顶位移增大,而墩底的曲率明显减小,且随着地震动强度的增加,基础的非线性影响更加明显。

The effects of foundation nonlinearity on seismic response of a bridge pier

According to the model test of a bridge pier with pile foundations,it is found that the Clough hysteretic model can be used to simulate the hysteretic behavior of the foundation systems.The bridge pier is idealized by the Takeda degrading hysteretic model in the plastic hinge.When the nonlinear seismic analysis of a railway simple supported beam bridge is performed,the strong earthquake records and the artificial wave are used as input ground motions.The effects of foundation nonlinearity on seismic response of the bridge pier are discussed under different kinds of input ground motions with different earthquake intensities.The results show that the foundation nonlinearity can usually magnify the displacement of pier top,and reduce the curvature of base pier.Furthermore the effects of the foundation nonlinearity with the increase of earthquake intensity are much significant.