基于粘弹性人工边界的阶梯地形地震波动问题分析

Analysis of seismic wave problem based on visco-elastic artificial boundary under the ladder terrain

针对阶梯地形地震波动问题,在粘弹性人工边界理论的基础上提出了1种新的"虚拟对称子结构体系"地震动输入技术。该技术不仅有效实现了对阶梯地形的波动输入,也解决了高差引起的输入地震荷载不一致问题。基于商业有限元软件对某典型算例进行动力时程数值分析,结果表明:所述方法具有较高的精确度和实用性;临空面位移幅值表现出显著的放大效应,且斜坡坡度越大,动力放大效应越明显。

Based on the study of problem of seismic waves by ladder terrain, a new seismic wave motion input meth- od of visco-elastic ar/ifical boundary suitable for this terrain by building a virtual symmetrical sub-structure system is proposed. This method not only simulates the seismic wave propagation validly but also satisfies the consistence of whole seismic input on outer boundary. Through the seismic dynamic responses of typical ladder terrain by finite element software, this method is proved to have highly computational accuracy and practicability;There is displacement amplification effect on airport surface, and the slope is greater, the dynamic amplification effect is more obvious.