冲击振动在砂土中传播的模型试验研究

Experimental Investigation on Propagation of Impact Load Induced Vibration in Sandy Soil

通过模型试验研究了冲击荷载引起的振动在砂土中传播和衰减的规律,并探讨了隔振板的隔振效果.结果表明:在模型箱边界处设置泡沫隔振板,能够较好地控制振动波在边界处的反射效应;在冲击荷载作用下,土体振动随测点与震源的距离增大而迅速衰减,加速度峰值沿水平、竖向和对角线方向的衰减可用公式amax=kR-β进行拟合;隔振板对隔振板后面的土体能够起到一定的隔振和减振作用,但对隔振板前面的土体起到了相反的效果,这是由于振动波在隔振板处发生反射的缘故.

Model test was performed to investigate the propagation and decay of impact-load induced vibration in sandy soil,and the effect of vibration screening panel was furthermore studied.The results show that the polystyrene wave-absorbing panel placed at the boundary of test box is effective in controlling the boundary reflection of vibration waves.The impact-load induced vibration decays rapidly with the increase of distance from the load point,and the attenuation of peak acceleration along horizontal,vertical and diagonal direction can be well fitted by the function of amax=kR-β.Polystyrene screening panel,behind which vibration can be reduced,has the negative effect of intensifying the vibration just before it,this may be caused by the reflecting of vibration wave at the screening panel.