Dynamic Behaviors of Rock with Initial Damage under Blasting Load

摘要

There are many faults in underground rock mass, and they can be considered as initial damage. In mine explosion, the dynamic behaviors of rock with initial damage are always perplexing. Using cement mortar including plastic foam to simulate the rock with initial damage, a series of impact tests were carried out with Hopkinson bars apparatus. Two kinds of dynamic damage evolution models were put forward and the corresponding constitutive models were derived. In these models, isotropic and orthotropic damages were assumed, respectively. Then the parameters in models were fitted with the experiment results. It was found the constitutive model of the orthotropic damage is more suitable to describe the dynamic behaviors of the rock with initial damage.