动力扰动下深部巷道围岩的力学响应及控制

Mechanical Response and Control of Surrounding Rock in Deep Tunnel under Dynamic Disturbance

为了研究动力扰动下原岩垂直应力、侧压力系数大小,以及扰动峰值强度对深部巷道围岩稳定性的影响,采用有限差分数值计算软件FLAC3D对动力扰动下深部巷道围岩力学响应进行数值分析,并结合冬瓜山矿山深部出矿巷道实际情况及现有支护方案,进行支护设计优化。研究结果表明:在动力扰动作用下,巷道围岩位移和塑性区都随原岩垂直应力、侧压力系数增大而增大;扰动峰值强度≤20 MPa时,巷道围岩位移和塑性区增大幅度较小,扰动峰值强度>20MPa时,巷道围岩位移和塑性区大幅度增大。故在较高的扰动强度和静应力作用下,巷道围岩更容易发生失稳破坏。在冬瓜山铜矿出矿巷道现有支护基础上,进行支护优化,得出最佳方案,即喷层厚度为150mm,混凝土强度等级为C20,优化后巷道围岩位移和塑性区大大降低。

The aim is to study the influence of the stability of surrounding rock with different vertical stresses,lateral pressure coefficients and peak value of dynamic stresses under dynamic disturbance. By using an explicit finite difference program FLAC3 D to study mechanical response of surrounding rock under dynamic disturbance,and combined with the practical situation of the Ore-drawing Roadway and supporting scheme in Dongguashan Copper Mine,the support optimization scheme is put forward. The results show that both the displacement and plastic zone increase significantly with the increase of the lateral pressure coefficients and vertical stresses under the influence of dynamic disturbance; when the peak value is less than 20 MPa,the displacement and plastic zones increase a little,but the peak value is more than 20 MPa,the displacement and plastic zones increase dramatically. So at a higher dynamic stress and vertical stresses,the surrounding rock is easily damaged. Based on the actual situation of Dongguashan Copper Mine＇s supporting scheme,the displacement and plastic zone of surrounding rock is reduced greatly after choosing the best support optimaization solution,namely the spray layer thickness is 150 mm,strength grade of concrete is C20.