不同地应力条件下含节理岩体爆破的数值模拟

将爆破损伤视为爆破应力波和爆生气体压力共同作用的结果,分别考虑不同的地应力条件(侧压力系数0.5、1和2,竖直方向地应力5 MPa和10 MPa)和节理角度(30°、45°、60°和90°),开展含节理岩体双孔爆破过程的数值模拟,研究爆生裂纹萌生—扩展—贯通过程的演化规律.无节理时,初始应力场对爆生裂纹的扩展具有一定的导向作用,裂纹扩展主方向趋于最大地应力方向.节理对裂纹的扩展方向具有一定的影响,节理角度为30°时,爆生裂纹与节理面连通,形成典型的‘之’字形断裂.节理对裂纹萌生和扩展具有明显的促进作用,有利于孔壁上下侧裂纹沿竖直方向的扩展. 

Numerical simulation of jointed rock mass blasting under different in-situ stress conditions

Two-hole blasting of jointed rock mass under different in-situ stress conditions(lateral pressure coefficient:0.5,1 and 2; vertical stress:5 MPa and 10 MPa) and joint angles(30°,45°,60° and 90°) was numerically simulated to study the process of crack initiation,propagation and coalescence. In the simulation,rock damage was induced by stress waves and explosion gas pressure. Simulation results indicate that for rock without a joint,the initial stress field has a guide role on crack propagation,and the crack propagation direction coincides with the maximum compressive principal stress. However,the existing joint has effect on the crack propagation direction. When the joint angle is 30°,the blasting induced crack connects with the joint and forms a "z" shape.The existing joint would play a positive role in promoting crack initiation and propagation and favor crack propagation along the vertical direction.