Study on deterioration mechanism of rock discontinuity under different dynamic disturbances

Dynamic disturbance is an essential factor leading to rock discontinuity’s deterioration and instability, which induces geological disasters such as collapses and landslides. To study the mechanical response characteristics and deterioration mechanism of rock discontinuity under different dynamic disturbances, the discrete element PFC is used to apply different waveform stress loads on the rock discontinuity with different roughness. The deterioration process of the structural plane is monitored and observed in real time to analyze the evolution of the deterioration process and the disaster mechanism of rock discontinuity under different dynamic disturbances. The results show that the peak shear stress of the structural plane under triangular wave disturbance is smaller than that under sine wave disturbance, and the difference is less than 1 MPa. With the increase in disturbance cycles, the loose degree of the strong force chain under sine wave disturbance is more significant, and the disturbance deterioration is more serious. The micro-cracks gradually develop and penetrate from the edge to the interior under sine wave disturbance and the opposite under triangular wave disturbance. Compared with the triangular wave disturbance, the crack growth rate is faster, the number of micro-cracks is higher, and the range is more extensive under sine wave disturbance, indicating it is more prone to deterioration.