非均匀介质在动荷载作用下的裂缝扩展研究

Crack Propagation Mechanism of Inhomogeneous Medium under Dynamic Load

运用岩石破裂过程分析软件RFPA-dynamic,通过对模型预置一组裂纹,研究裂纹倾角、岩桥倾角及双向荷载对裂纹扩展方式的影响。结果表明:1单向动荷载作用下,裂纹倾角和岩桥倾角对裂纹扩展方式几乎没有影响,裂纹大致沿与荷载垂直的方向扩展;2单向动荷载作用下,声发射释放累积能量的过程大致分为4个阶段;3双向动荷载作用下,随着荷载比率的减小,裂纹的弯曲弧度增大,逐渐与水平荷载垂直;4双向动荷载作用下,岩桥倾角一定时,随着裂纹倾角的增大,裂纹扩展偏向竖直方向;5单向静荷载作用下,裂纹倾角和岩桥倾角对裂纹扩展方式有显著影响,而单向动荷载作用下,其对裂纹扩展方式却几乎无影响。

The influences of crack inclination angle,rock bridge＇ s inclination angle and biaxial load on rock crack propagation mode were studied by using Rock Failure Process Analysis（RFPA-dynamic） on rock samples with preexisting cracks.The results show that 1） under uniaxial dynamic load,crack inclination angle and rock bridge＇s inclination angle have little effect on crack propagation,and the crack expands in the direction perpendicular to load ; 2） the release of accumulated energy of acoustic emission can be divided into four stages under axial dynamic load; 3） under biaxial load,along with the decrease of load ratio,the bending radian of crack increase and the crack is gradually perpendicular to the horizontal load ; 4） when the inclination angle of rock bridge is constant with the increase of crack inclination angle,crack tends to the vertical direction under biaxial dynamic load; 5） under uniaxial static load,crack inclination angle and rock bridge＇s inclination angle have significant effect on crack propagation mode but have little effect under uniaxial dynamic load.