Study and Application of Rock Breaking Mechanism of Concentrated Water Hydraulic Smooth Blasting in Broken Sand-Stone Geological Conditions

Abstract

The use of polyenergy water pressure controlled blasting technology in tunnel construction is gradually being promoted, and the technology is often used in hard rock, and the mechanism of rock breaking in fractured sandstone strata is still lacking systematic research. The above mechanism was investigated using a combination of field experiments and ANSYS/LS-DYNA numerical simulation, and the results showed the following: (1) In the case of joint-hole blasting, the concentrating jet formed by the concentrating tube can effectively achieve controlled directional blasting of fractured sandstone. (2) The use of gun clay to seal the hole can effectively improve the stability of the blasting effect, reduce the waste of explosive gas, and effectively extend the duration of action. (3) The water bag enhances the blasting effect through the water wedge effect in the broken surrounding rock and also has the function of energy storage, which can effectively improve the blasting effect when combined with the gun clay. (4) The rock-breaking mechanism of polyenergy hydropressure smooth blasting in fractured sandstone geological conditions is the dual rock-breaking action of “polyenergy jet + water wedge action.” (5) In this article, based on the analysis of blasting mechanism, the deployment method of polyenergy hydropressure smooth blasting is designed and has been well applied in engineering practice.