水平边界条件下深孔微差爆破的数值模拟

Numerical Simulation on the Millisecond Blasting for Deep Boreholes Under the Condition of One Horizontal Free Surface

目的研究水平边界条件下深孔微差爆破的作用机理．方法采用动态非线性有限元法对单个水平自由面深孔微差爆破进行数值模拟．根据模拟结果分析岩块运动和槽腔内岩块的破坏方式．结果孔底部分的岩石主要以冲击压缩破坏为主，而自由面附近的岩石主要以层裂破坏为主．结论掏槽孔的爆破作用和微差时间的确定是影响微差爆破的重要因素。

Aim To investigate the mechanism of the millisecond blasting for deep boreholes under the condition of one horizontal free surface.Methods\ Numerical simulation on the millisecond blasting for deep boreholes with one horizontal free surface was conducted using the dynamic nonlinear finite element method. The movement of rock mass and its damage form in the cave were analyzed based on numerical results.Results\ The rock damage near the bottom of boreholes was mainly in the form of shock compression, near the free surface in the form of spallation. Conclusion\ The blasting action of cut holes and delay time are important factors affecting millisecond blasting, the constitutive behavior of brittle rock is described well using the elastic plastic model with oriented cracks.