Influence of Inclined Joint on Dynamic Response of Rectangular Opening Subject to Blast-Induced Stress Wave

In deep mining engineering, the structural plane such as joints or fractures has a significant influence on the dynamic response of underground opening subject to blast-induced stress wave. In this work, a numerical model was established using the particle flow code (PFC) to investigate the effect of stress waves on the dynamic response of openings. In particular, different inclination angles (i.e., 0°, 15°, 30°, and 45°) were considered in the presence of joints to analyze the evolution laws of stress and energy around the opening and characterize the propagation path and superposition of stress waves between the inclined joint and the opening, thereby revealing the dynamic failure characteristics of the opening. The results show that the superposition zone of stress waves can be divided into tensile zone, shear zone, and compression zone, which determine the spalling failure mode of the opening, and the spalling failure to opening is the most severe when the joint inclination angle is 45°. The gradient stress distribution results in the spalling crack on the opening presenting as arc groove spalling. In addition, the increase in lateral pressure coefficient restrains the spalling failure but causes rock burst. The results of this study could provide value for engineers to form a better understanding of the influence of structure planes on the dynamic response of the opening, which would be beneficial to the opening support design.