Study of decoupled charge blasting based on high-speed digital image correlation method

Incorporating high-speed camera technology, an experimental system of high-speed digital image correlation is established and extended to blasting research. Based on the model experiment, the effects of the filling medium and the decoupling coefficient on stress evolution in decoupled charge blasting are studied. Different filling media are found to have a significant effect on the transmission of blasting energy. Compared with coupled charge blasting, decoupled charge blasting with air as the filling medium reduces the blasting stress peak in the specimens; while within a certain decoupling coefficient range, the decoupled charge blasting with plasticine as the filling medium increases the blasting stress peak in specimens. The blasting stress-attenuation index in specimens exhibits the trend of an initial increase and then a decrease with increasing decoupling coefficient, where the decoupling coefficient corresponding to the maximum stress attenuation index is determined by the filling medium. In addition, the numerical simulation results show that, in decoupled charge blasting, the filling medium greatly reduces the pressure at the borehole wall. With increasing decoupling coefficient, the pressure at the borehole wall attenuates with a mild degree of attenuation.