Analysis of spatial damage characteristics of rock under multiple high-voltage pulse discharges: I. Cross-section characteristics

Rock breaking by high-voltage pulse discharge (rock breaking by high-voltage pulse discharge, RHPD) is an efficient technology for rock breaking. A single discharge will lead to the initiation or expansion of cracks inside the rock, and the expansion of cracks after multiple discharges will lead to the destabilization of the rock and finally produce a fractured zone. Because of the difficulty in quantifying the spatial damage characteristics of the fractured zone, in this paper, based on the discrete element method and theoretical analysis, the spatial damage model (spatial damage model, SDM) of rock is established. For a typical liquid-solid combination, from the microscopic point of view, the damage characteristics of the fractured zone on the radial cross-section of the plasma are quantified. The changing characteristics of the damage characteristics were analyzed for multiple discharges. In addition, an experimental platform has been built, and the accuracy of the SDM has been verified by the experimental results. The results show that the increase in the discharge distance will improve the deposition energy and crushing effect, and will also improve the accuracy of the model. The findings of this paper provide a technical reserve for the application of RHPD.