单向静载下柱状药包爆破裂纹扩展规律及机制

Crack propagation rule and mechanism of cylindrical blasting under uniaxial static load

将岩体内柱状药包爆破简化为平面应变问题,采用ANSYS/LS-DYNA软件进行数值计算,研究单向静应力对爆破裂纹的影响规律及机制。结果表明:无静应力时,爆破裂纹区形状大致为圆形;而施加单向静应力后,裂纹区形状演化成椭圆形,椭圆的长轴方向与静应力方向相同,且随着静载荷增加,裂纹区长轴基本保持不变,短轴长度降低。这是由于随静载荷变化,沿着加载方向单元的最大主应变基本不变;而垂直加载方向单元的最大主应变随着静载荷增加而减小,从而导致该方向裂纹长度降低。

The cylindrical blasting in rock mass was simplified as plane strain problems and the effect of uniaxial static stress on blasting crack was studied by ANSYS/LS-DYNA software.The results show that the shape of the crack area is roughly circular when no static stress is applied,while the crack area is elliptic after the static stress is applied.The long axis direction of the ellipse is the same as the static stress direction.As the static load increases,the long axis of the crack region remains unchanged,and the length of the minor axis decreases.This is because the maximum principal strain along the loading direction is basically unchanged with increasing static load;and the maximum principal strain of element in the vertical load direction decreases,resulting in the crack length decreases.