Abstract:
To study the blasting process in an open mine slope, based on the theory of energy conservation, it was assumed that all the chemical energy released during explosion was transmitted to the surrounding rock body within a certain range and partially converted to kinetic energy, then the explosion energy was transferred and absorbed in the fractured and damping rock until the ultimate balance at the end of this dynamic process. The PFC3D simulation platform was employed to calcaulate the singlehole blasting processes with different heights, buried depths and charge amounts in the open mine slope, and the slope stability after blasting was discussed. The simulation results show that: the blasting process can be divided into 3 phases. In the first phase, the explosion impact plays a leading role, accompanied by the reverberation of the velocity vectors. In the second phase, gravity is the dominant factor for the collapse of the overburden rock. In the third phase, some particles roll or slip down and end in balance. The time length of the following phase is bigger than that of the preceding one by almost 1 order of magnitude. In general, the upper sandstone is stable after all sorts of blasting, i.e. the slope top is stable. The lower sandstone and sandy mudstone are subject to a certain degree of damage but still in control.
