Numerical simulation of rock fractures induced by CO2 blasting

Abstract

As a safe and environment-friendly rock breaking technique, CO2 blasting has been paid more and more attention. Most of previous researches estimate the radius of rock damage induced by CO2 blasting according to explosive equivalent method, with less attention to the mechanism. In fact, compared with explosive blasting, the peak pressure and loading rate of CO2 blasting are several orders of magnitude smaller. In order to further understand the mechanism, the commercial software LS-DYNA and Riedel-Hiermaier-Thoma material model have been used to simulate the rock fractures induced by CO2 blasting. First of all, according to the previous researches, the ranges of the rise time and corresponding peak pressure of CO2 blasting are estimated. Then, influences of the key parameters in blasting, viz., loading rate, in-situ stress and free face, on fracture patterns are explored. In the present study, the fracture patterns of CO2 blasting are successfully simulated, and some of the well-known phenomena observed by other researchers can be reproduced. The numerical simulation in the present study has the potential to be applied in practical CO2 blasting.