Quasi-static Model for Rock Damage Caused by Closed Explosion of Spherical Charge

Abstract

Aiming at the closed explosion in rock,a model for predicting breakage zones caused by spherical charges was established. The radii of explosion cavity,comminuted region and cracked region in rock were obtained based on the elastic-comminuted-cracked response model,and the adiabatic relation of the detonation gas before and after explosion was considered. The Hoek-Brown criterion was used to describe the material in comminuted region. The blasting cavity results from the proposed model agree well with the experiment in references with relative error range from -5.8% to 5.5%. The results of quasi-static model based on the Mohr-Coulomb criterion are smaller,and the formula of cylindrical blasting cavity is not applicable to the spherical blasting cavity. As the value of dimensionless coefficient m in the Hoek-Brown criterion increases,the size of blasting cavity decreases. The predicted results in radius of comminuted region and crack region are reasonable and less affected by m.