The propagation of stress waves in rock impacted by a pulsed water jet

Abstract

Pulsed water jets have been widely applied in the field of underground mining because of their unique advantages. Revealing the mechanical mechanism of rock breaking under a pulsed water jet is significant in advancing the application of pulsed water jets in the rock crushing process. Based on continuum mechanics and interpolation theory, this paper establishes a numerical model to simulate the propagation of stress waves in rock by adopting the method of smooth particle hydrodynamics (SPH). According to the simulation results, this paper presents a quantitative approach to schematize the propagation of stress waves in the time-space dimension. The waveforms of stress waves in the selected path and the effective stress history of test particles are obtained to quantitatively describe the propagation of stress waves. Relying on the approach, the effects of jet velocity and rock properties on the propagation of stress waves are investigated. The results show that in the rock model, the influence area, propagation speed and attenuation rate of the stress wave all increase with increasing jet velocity. Moreover, the mean effective stress of a test particle in the numerical model increases with increasing jet velocity. Of the rocks considered in this paper, granite shows the greatest mean effective stress acting on the test particle, propagation speed, and attenuation rate of the stress wave.