Numerical Analysis of Directional Rock Blasting with Continuous-Discontinuous Element Method

Abstract

When simulating the directional blasting process, many researchers focus on the cutting and splitting effects who might pay more attention on the crushing effects when studying conventional cut blasting. In this case, a numerical tool capable of capturing the strong discontinuity processes of quasi-brittle materials is highly preferable, where many blasting parameters should be calibrated and inputted. In this work, a hybrid finite-discrete elements method with explicit iterative procedure named Continuous-Discontinuous Elements Method (CDEM) is adopted to study the directional rock blasting processes. Landau model is used to capture the detonation effects, where the parameters are calibrated by comparing to the results provided by published literatures. We found that: i) The crack propagation mode of directional rock blasting is similar to those found in Brazilian splitting tests where the crack initiates from the midpoint of the connecting line of blast holes; ii) Compared with traditional cut blasting, the free surface has no significant influence on the blasting effect of directional cut blasting, while the spacing of the hole has great influence on the cutting effect. The index of fracture degree can be used to evaluate the blasting effect quantitatively. This work partly reveals some cracking patterns and rules of directional rock blasting, which may assist the engineers to develop improved precise blasting technologies.