Applying the theories of blasting shock wave and based on the hypothesis that the rock belind the shock wave front is incompressible, the formation and radius of smashed district, expanding law and radius of blasting cavity and formation and radius of craked district are discussed, and the concept of crashed district in rock is put forward, which is induced by explosion shock.

According to the confining pressure environment of high-stress soft-rock failure and its failure characteristics under this environment, the mechanism of high-stress soft-rock Problem is analysed and a differential equation discribing the relation between openings converging end failure zone s expanding is established.

The main issues are covered in blasting cave range,various determination methods for failure zones, theories of short-wave and weak-wave in near-field of cave blasting,the movement in plastic regions and mechanical parameters in far-field,and rock fracture under blasting for underground works.