地震波频率对巷道围岩动力响应的影响

Effect of earthquake wave frequency on dynamic response of tunnel

为了研究地震波频率对巷道围岩动力响应的影响,建立了5个围岩性质不同的巷道模型,利用动力有限元方法分别对各模型在0.2、0.5、0.7、1、1.5、2.5、4、6、9、12、15Hz等11个频率的地震波作用下的围岩动力响应进行了数值模型,并对各模型在不同频率地震波作用下的最大动应力变化情况进行了分析。结果表明,在输入波动的振幅特性不变的情况下,某一频率或频率范围的波动能够激发模型的最大响应。随着模型介质剪切波速的增大,最大响应频率逐渐由低频向高频移动。

In order to study the effect of frequency of earthquake wave on the stress state of tunnel enclosing rock, the dynamic finite element method is used to simulate the dynamic response of tunnel enclosing rock under shear wave load. Five tunnel models are built in, which the mechanics and physical characters of tunnel enclosing rock is different. To each model, the shear wave with frequency of 0.2Hz,0.5 Hz,0.7 Hz,1 Hz, l.5 Hz,2.5 Hz,4 Hz,6 Hz,9 Hz, 12 Hz and 15 Hz individually is input from the bottom of the model. The simulation results indicate that, to each model, if the maximum amplitude and the wave mode of input shear wave is invariable, the shear wave with certain frequency may induce the maximum dynamic response in the enclosing rock of tunnel. As the increasing of wave velocity of enclosing rock, the maximum dynamic response frequency of shear wave increase.