地震表面波引起高桥墩的动力屈曲分析

考虑大变形的影响,建立高桥墩在地震表面Rayleigh波引起的地基椭圆运动时的非线性动力学基本方程式.通过位移形函数假设,采用伽辽金积分方法得到了时间变率的动力学控制方程.对时间变率的非线性微分方程进行数值求解,给出了同一地震波不同强度下高桥墩的位移响应曲线以及从产生横向振动到失稳的全过程,得到了地震波冲击时高桥墩失稳的临界地震加速度和失稳时刻.通过数值算例比较了地震波幅值、高桥墩柔度以及桥面质量大小对位移幅值响应曲线、临界地震加速度和失稳时刻的影响.

Dynamic Buckling of the High Pier under the Surface Wave by Earthquake

Considering the influence of large deformation,the non-linear dynamic equations of a high pier under the foundation ellipse motion caused by Rayleigh wave by earthquake were established.By supposing the displacement shape function and applying the Galerkin method,the dynamic equations about time were obtained.By processing numerical calculation,the displacement response curves of the high pier under the foundation ellipse motion with different magnitude and the overall process from the transverse vibration to the instability of the high pier were given.The critical seismic acceleration and the instability time were obtained.The influence of different seismic peaks,the slenderness ratio and the weight of the bridge on the displacement response,the critical seismic acceleration and the instability time were analyzed.