Numerical Simulation of Influence of Hollow Hole on Blasting Effect of Parallel Cut

Abstract

To study the influence of hollow hole on blasting effect of parallel cut, two three-dimensional parallel cut models with or without hollow hole were established by using the nonlinear dynamic analysis platform ANSYS/LS-DYNA. The evolution history of explosive stress field and the failure characteristics of rock mass were compared and analyzed. The results indicated that the stress concentration was occurred around hollow hole obviously due to the reflection of stress wave. The peak equivalent stress of the measuring point on borehole wall is 107.0 MPa for the model with hollow hole. The peak equivalent stress of the measuring point on middle zone is 20.3 MPa for the model without hollow hole. Rock mass in cut cavity can be fully destroyed with hollow hole. Penetrating cracks are formed between cutting holes and hollow holes. The phenomenon of spallation is formed at the wall of hollow hole. Poor fragmentation length of rock mass in the middle of cut cavity and small utilizing rate of blasting holes are formed for the model without center empty.

Keywords

• parallel cut
• hollow hole
• explosive stress filed
• blasting effect
• numerical simulation