Interactions of 3D embedded parallel vertically inclined cracks subjected to uniaxial compression

Sets of embedded parallel joints are frequently encountered in geotechnical engineering. The interactions between these embedded parallel joints have significant influence on failure process of rock mass. To investigate the interactions of joints, the present paper firstly develops a simple constitutive model based on the augmented virtual internal bond (AVIB) method, by which no separate fracture criterion is needed in simulating fracture propagation. To simulate the pre-existing cracks, the 3D element partition method is employed, which avoids the problems of specially setting up joint element and modification of mesh scheme. The simulation results suggest that when the parallel cracks are vertically aligned, they propagate independently in wrapping wing pattern, but there is neither prior propagation nor coalescence path. In contrast to the aligned vertically parallel crack cases, the nonaligned vertically parallel crack case has prior propagation and coalescence path. The crack always propagates toward and coalesces with its adjacent crack by which a wing crack array is formed. During the wing-array cracks' propagation and coalescence, the other crack's growth is restrained to a certain extent due to the release of stress concentration. The drawn conclusions provide meaningful reference for the analysis of landslide of jointed rock slope.