Study on Blasting Characteristics of Soft-Hard Rock Strata Based on Energy Fields and Particle Expansion Loading Algorithm

Complex geological conditions often make the blasting effect difficult to control. In order explore influence of soft-hard rock strata on characteristics, based PFC2D software, combined with particle expansion loading algorithm, numerical simulation experiments are carried out. Firstly, rationality method is verified by single-hole sandstone experiment. Then, composite established, and strata, different distribution thickness soft stratum hard stratum, The experimental results analyzed from three perspectives: crack network state, internal stress mass, energy field. Results show that (i) distance between interface blasthole seriously affects effect. law number varying obtained through further analysis. (ii) When detonated in rock, if structural plane about 2 times radius crushing area blasthole, mass will be a relatively high state due reflection superposition waves. (iii) compared pure case, peak kinetic friction increased 15 2.6 times, respectively, strain attenuated 18%.