动力扰动对采空区稳定性影响的离散元分析

 采用离散元程序对地下采空区进行动力扰动数值计算，通过改变扰动应力波峰值的大小，考查动力扰动强度的变化对采空区稳定性的影响，对模型分别静力和动力状态下进行了计算。结果表明，采空区开挖后，最大位移量2.98mm；施加动载荷后，最大位移量增至5.0mm，增幅与动载荷应力大小呈正比；围岩位移、最大主应力、最小主应力分布受动载荷影响较大，围岩应力发生二次分布，塑形区明显增大。分析结果表明，邵东采空区基本稳定，但应加强顶板、底板支护。为了避免采空区在外力扰动下产生灾害，给出了建议。

Stability Analysis of Underground Goaf Influenced by Dynamic Disturbance with Dimensional Distinct Element

By using an dimensional distinct element program, a model for numerical calculations is established for a goaf underground with dynamic disturbance. And then the effect of disturbance intensity on the stability of goaf underground is studied by changing the peak value of the dynamic stress wave, and the static calculation and the dynamic calculation are carried out, respectively. The analytical results demonstrate that the maximum displacement of surrounding rock is 2.98mm after goaf underground is excavated, while the maximum displacement of surrounding rock increases to 5.0mm after the dynamic loading is applied, and the amplitude of the increased displacement is proportional to the magnitude of the dynamic loading, which influences the variation of displacement, maximum principal stress, minimum principal stress distribution for surrounding rock. The second redistribution of stress field of surrounding rock occurs; and the distribution area of plastic zone is expanded significantly. The results show that Shaodong mined-out area is stable, but the support of the top and bottom should be strengthened. Several suggestions to avoid instability and subside of mined-out areas induced by blasting vibration are made.