Joints and fissures have a strong impact on the stability of engineering rock mass. In this paper, a self-improved analysis program of FLAC3D is adopted to study problems in fluid-solid coupling field. Then, by simulating the excavation process of a slope under the effect of fissure water pressure, the crack initiation and propagation in engineering rock mass reappears. Besides, the numerical simulation results are decent and effective, which can provide some references for engineering application.

In this paper, the failure mechanism of rock-like specimens with built-in 3D double cracks under fissure water pressure was numerically investigated. The initiation and propagation process of secondary cracks under fissure water pressure was simulated by using the modified elasto-brittle model and the superfine meshing method in the FLAC3D program. The fluid-solid coupling in cracked rock masses was preliminarily studied. Some of the simulation results are in good agreement with the previous results tested by scholars.