动力扰动下高应力巷道围岩动态响应规律

 采矿过程中,爆破震动等动载荷常会导致高应力巷道失稳塌陷,诱发岩爆发生。根据弹性力学和应力波理论,分析扰动波诱发高应力巷道失稳破裂的机制。针对用沙坝矿高应力巷道受到动力扰动破坏的情况,运用颗粒流软件PFC^2D对动载荷作用下高应力巷道的稳定性进行数值计算,通过改变动载荷幅值的大小,探讨扰动应力波强度的变化对巷道围岩应力场、位移场及破坏区范围的影响,对模型采用静力和动力两种计算方案。研究表明：动载作用下巷道围岩应力场、位移场及破坏区范围相对静力计算结果显著增大;随扰动应力波强度增加,巷道顶、底板的应力、位移及裂纹数量也显著增加。为了避免动力扰动诱发高应力巷道失稳塌陷,给出了几条建议。

Dynamic Response of Surrounding Rock in Highly-stressed Tunnel by Dynamic Disturbance

The dynamic loading due to blasting vibrations often leads to local instability of the highly-stressed tunnel and the rock burst during mining. Based on the elasticity and the stress wave theory, the mechanism of the instability and the crack development due to the dynamic vibrations in the highly-stressed tunnel are analyzed. In order to see why the highly-stressed tunnel in Yongshaba mine might be severely destroyed by dynamic vibrations, the numerical simulations of the highly-stressed tunnel under dynamic loading are carried out with the particle flow software PFC^2D, and the effects of the disturbance stress wave intensity on the stress fields, the displacement fields and the crack fields in the surrounding rock are investigated by varying the peak value of the dynamic loading. The static and dynamic calculations are carried out, separately. The results show that the extents of the stress fields, the displacement fields and the crack fields in the surrounding rock under a dynamic disturbance will increase obviously as compared to the static calculation results. The higher the disturbance stress wave intensity, the more significant the dynamic disturbance influences on the stress, displacement and crack fields both in the roof and the floor of the tunnel will be. Several suggestions are made to avoid the instability and the subsidence of the highly-stressed tunnel induced by the dynamic disturbance.