深厚覆盖层中地震动传播规律离心模拟试验研究

Dynamic centrifuge modeling research on the propagation law of earthquake motion

深厚覆盖层上高土石坝抗震问题一直是土石坝抗震研究领域的热点之一,而地震动在覆盖层中传播规律研究是其重要组成部分,为揭示地震在覆盖层中的传播机理,本文开展了离心机振动台试验,分别研究了输入加速度峰值、土层特性对于地震动在其中传播规律的影响。研究发现,地震动经覆盖层传播后,低频成分被放大,高频被抑制,且随着输入地震动峰值增加,地震动加速度峰值放大倍数逐渐减小,而对于相同的地震动输入,加速度峰值放大倍数随着土体剪切刚度的增加而逐渐变大。

The seismic behavior of high earth rockfill dams built on a deep overburden layer is one of theresearch hotspots in the field of anti-seismic engineering of those dams. The propagation behavior of seis-mic waves through the overburden layer is the important part of the aforementioned research. In order to ex-amine such a propagation behavior of seismic waves through the overburden layer,a series of dynamic cen-trifuge tests were carried out in this study. The influence of the peak acceleration of the input motion andthe soil properties on the propagation behavior of seismic waves was explored. This study indicates that thecomponents of seismic waves with low-frequencies become strengthened while those with high-frequenciesbecome weakened after propagation through the soil. In addition,the amplification factor of the peak accel-eration decreases with increasing the peak acceleration of the input motion. Meanwhile,amplification factorincreases with increasing the shear modulus of the soil for the same input motion.