Abstract: Based on damage mechanics theory, a mechanical model for rock blasting is established considering of the rock heterogeneity, in which rock blasting is considered as two consecutive stages, i.e. the dynamic stage caused by the stress wave and the static stage caused by explosion gas pressure. The cracks evolution of two-hole blasting under different in-situ stress conditions is numerically simulated. The numerical results indicate that: ① the initiation of cracks is induced by the blasting stress wave, while the explosion gas pressure can lead to the further propagation of cracks; ② the cracks evolution is closely related to the in-situ stress conditions, and the cracks propagation direction coincides with the maximum compressive principal stress; ③ the cracks radius and cracks area decrease with the increasing of depth and in-situ stress, which implies the suppression of in-situ stress on blasting fracturing.

Key words: in-situ stress conditions, two-hole blasting, blasting stress wave, explosion gas pressure, numerical simulation