In order to achieve intelligent blasting and reduce the blast-induced adverse influences

the prediction of rock damage and its distribution scope through numerical simulation is of importance in engineering. Thereinto

the reasonable damage constitutive model for rock is crucial. By assuming that the rock mass is an isotropic and continuous material with pre-existing random initial microcracks

an available rock tensile damage evolution equation considering time effect is coupled with the bi-linear elastoplastic constitutive model. Then they are succinctly incorporated into the transient dynamic code

LS-DYNA

via its user defined subroutine. In addition

the erosion algorithm in LS-DYNA is employed. The tensile damage and blasting crater near the free-surface of semi-infinite rock mass is numerically simulated; and the numerical results are satisfactory. This method presented herein has some reference value in rock blasting.