成层地基地震动输入方法研究

On seismic input method for layered foundation simulations

目前成层地基的地震动输入时大多仅考虑不同材料的波速影响,忽略了波在不同介质分界面的透射和反射作用。为真实模拟弹性波在成层地基中的传播过程,本文基于波动理论,推导了考虑透射和反射的等效荷载计算公式,建立了成层地基的黏弹性人工边界模型,并通过算例进行验证。研究表明:本文提出的成层地基地震动输入方法能较好满足工程抗震的精度要求,为成层地基的结构抗震提供了一种有效和实用的计算方法。

At present,most of the ground motion inputs for layered foundation simulations consider only the influence of different materials on wave speed,ignoring the refraction and reflection of waves at the interfaces of different media.To improve the simulations of elastic wave propagation in layered foundation,this study derives an equivalent load calculation formula considering the media interface refraction and reflection based on the wave theory,and constructs an artificial viscous-spring boundary model of layered foundation.We verify the model through example analyses.The results show this seismic input method can better meet the accuracy requirements of anti-seismic engineering,and is effective and practical for layered foundation design.