不同边界和地基条件的大型滑坡体动力响应分析

Research on seismic response of large-slipmass based on different boundary conditions and foundation conditions

动力有限元计算结果的真实性与模型边界条件的设置和地震波输入高程的选择有着密切的关系。采用动力有限元时程分析法对不同边界和地基条件的大型滑坡体进行了数值计算,在此基础上分析了地基辐射阻尼和地震加速度输入高程对滑坡体动力响应的影响,以及大型滑坡体的地震响应规律。结果表明,上田镇大型滑坡体在动力作用下上部的位移响应值大,剪应力小,而下部则相反;黏弹性边界能有效地降低滑坡体的地震反应,而且地震输入高程的不同对滑坡体的地震响应会产生相当大的影响,地基辐射阻尼和地震波输入的模拟合理性直接影响滑坡体动力分析的客观性。

The authenticity of dynamic finite element＇s results has a close relationship not only with boundary condition and the inputted datum of seismic wave.This paper calculates seismic response of large slipmass under different boundary conditions and inputted datum with time history method.On the basis of the calculating results to analyze the impacts which arise from radiation damping and inputted elevation on seismic response of slipmass and the law of seismic response.The results demonstrate that the upper part of Shangtian-town large slipmass has large displacement response and small shearing strength;but the response of lower part is opposite to the upper.Viscoelastic boundary can reduce the seismic response of slipmass;and the change of inputted elevation of earthquake wave can produce considerable influence on seismic response.The simulative rationality of radiation damping of foundation and inputted elevation of earthquake wave can influence the objectivity of seismic analysis.