Experimental study on the influence of block rock fracture on P-wave propagation of block rock mass

Abstract

Abstract The fracture of a rock mass is an important stage in the development of catastrophes in a block system. In this paper, the characteristics of P-wave propagation in block rock mass containing fault block are investigated experimentally. Velocity of P-wave, acceleration, acceleration response duration, kinetic energy, displacement and time-frequency characteristics of block rock mass dynamic response are analyzed. The results show that P-wave velocity decreased, duration of acceleration increased, acceleration and kinetic energy maxima decreased on block rock mass fractured. The differences between block rock transverse and longitudinal fractures are as follows: acceleration and kinetic energy of the rock masses near the fracture area decreases more significantly and the principal frequency decreases during transverse fractures. However, the effects of longitudinal fractures are more pronounced far from the fracture area. Displacement is related to the position of the block from the fracture. When close to the fault zone, displacement amplitude decreases, dominant frequency of displacement increases, and dominant frequency reaches earlier. When far away from the fault zone, displacement amplitude increases, main frequency of displacement decreases, and main frequency arrives late.