深埋硐室高围压条件下的围岩动力学响应

Dynamic response of surrounding rock with high stress in deep chamber

地下硐室开挖过程中,应力波对硐室周围围岩位移及其应力应变变化规律起着十分重要的作用,准确分析应力波对硐室围岩的影响规律,不仅可以作为检验施工设计的依据,而且可以预测预报围岩的稳定性和调整开挖方式、支护设计等,从而合理地指导施工。利用三维快速拉格郎日法(Flac3D有限元分析程序),以冬瓜山铜矿某破碎硐室为实例,在硐室围岩模型的上边界施加动力载荷,以模拟外界动力扰动对硐室围岩稳定性的影响,再通过加载峰值,来考察动载强度对硐室围岩的影响,得出了硐室围岩在不同时刻的应力和塑性区分布情况。研究表明:当扰动应力波来自硐室围岩竖直方向时,其对硐室拱顶和底板围岩的稳定性影响较大;当扰动应力波来自硐室围岩水平方向时,其对硐室侧壁围岩的稳定性影响较大。

During the deep chamber is excavated, stress wave plays a very important role effecting the chamber surrounding rock in the regularities of displacements and stress-strain. Accurate analysis of it is important in deciding the construction sequence for big cavern and instability. By using the fast Lagrangian analysis of continua in 3-dimensions （finite element analysis software - Flac3D）, taking the fragmentation chamber of Dongguashan copper mine as an example, one dynamic load is applied on the above boundary of the chamber model , the dynamic response of the surrounding rock is simulated and calculated. We observed the influence of the intensity of dynamic load to wall rock of chamber to get the distribution of stress and plastic area of it in different time by loading the peak value of dynamic. The simulation study results shows ： it affects the stability of the chamber vault and wall rock of bottom board much when perturbation strain wave comes from erect direction of chamber wall rock; and it affect the stability of wall rock of chamber parietal much when perturbation strain wave comes from horizontal direction of wall rock of chamber.