断续节理相互作用的数值模拟

Numerical Simulation of Interaction Among Intermittent Joints

运用岩石破裂过程分析RFPA2D系统,研究了断续节理岩体中裂纹的产生与扩展机理,不同断续节理分布岩体的变形、破坏过程以及节理之间的相互作用和影响规律.研究指出,共线节理的裂纹产生并不相互影响,其裂纹扩展是各自独立地平行于压应力方向;左梯式节理的裂纹产生是相互作用的,主生裂纹沿压应力方向扩展,而次生裂纹沿垂直于节理面方向扩展一定长度后转向水平方向很快贯通于相邻节理;右梯式节理的裂纹产生并不相互作用,主、次生裂纹形成后各自沿压应力方向扩展,并不会贯通于相邻节理.裂纹的扩展是由于裂纹尖端的拉应力作用的结果.当节理在压应力作用下所产生的次生裂纹扩展达到相邻节理后,岩体就会产生贯通裂纹而破坏.

The mechanism of crack furring and propagating in jointed rock mass was studied by using rock failure process analysis code（RFPAZD）. Deformation, failure process of the rock with different joint distribution and interaction among joints were analyzed. The results show that, in the process of forming the cracks from collinear joints, they are not influenced on each other, each of which expands independently along the direction parallel to the compressive stress. However, in forming the cracks of the left step joints, they have an interaction on each other, with the main cracks 1 expanding along the direction of compressive stress, while secondary cracks expanding first along the direction perpendicular to joint plane and then turning to the horizontal direction to penetrate adjacent joints quickly. For the right step joins, the formation of cracks does not interact on each other and the main and secondary cracks expand respectively along the direction of compressive stress without penetrating the neighbor joints. Under compressive stresses, tensional failure will occur in the rock bridge of the end of joint, which leads to connect new cracks of rock bridge with the nearby primary joints. Finally, the slid plane of step-shaped forms and rock mass strength is lost.