Abstract：Applying the theory of cavity expansion，the characteristics of cracked zones under rock blasting are studied according to the behavior of blasting-induced deformation and damage of rock. The expansion and squeeze course of cavity wall under the explosion gas，the crack limits and the time history of stress on the interface between cracked and the uncracked zones are presented. The radium of blasting cavity，stress peak value and action time of stress waves are validated by the theory of classical explosion mechanics and the way of curve regression. The results of numerical calculation analysis keep good consistence with that given by traditional mechanics.
