Study on the Mechanical Behavior of Empty Holes on Blasting Crack Propagation.

In order to explore the affluence of empty hole on the propagation of biasing cracks, an empty hole blasting damage model is established by comb mg ANSYS/LS-DYNA finite dement software. The equation of stress distribution n the rock mass near the empty hole is deduced theoretically, and the Influence of empty whole effect on the fracture mechanism and crack propagation is analyzed. The results show that the free surface effect of empty hole will cause the sudden Increase of impact pressure and the change of seismic velocity near the empty hole, which leads to the phenomenon of "falling" of rock at the blasting surface. The shock velocity at the back surface of the empty hole is significantly smaller than that at the front surface, which indicates that the empty hole has a good effect of pressure relief and shock reduction. By comparing the analytical solution of the impact pressure and the radius of the fracture zone with the numerical calculation results it is found that the error rate of the impact pressure is 11.81%, and the error of the rams of the fracture zone is only 9.49%, which proves the accuracy of the simulation results in this paper. [ABSTRACT FROM AUTHOR]