Experimental study of high-speed particle jets impacting deep hard rock under true triaxial stress

To investigate the jet breaking mechanism of hard rocks under three-dimensional stress, jet breaking experiments under different ground stresses and horizontal stress differences were performed. The results showed that the rock-breaking holes were in the shape of an inverted & omega;. The ground stress had an obvious effect on the rockbreaking performance of the jet. As the ground stress increased, the rock strength increased, and the rockbreaking performance decreased by 28.56%. At ground stresses greater than 50 MPa, the rock-breaking performance increased by 20%. The horizontal stress difference made the pore wall stress concentrated and loosened the cementation between mineral particles. As the stress difference increased, the roughness increased, and the rock-breaking performance increased by 58.85% while the energy consumption decreased by 25.56%. The results of this study provide data and technical support for the jet breaking of hard rock in deep mine construction.

Automated summary

Jet breaking experiments were conducted to investigate the mechanism of hard rocks breaking under three-dimensional stress. The shape of the rock-breaking holes resembled an inverted & omega;. Ground stress had a significant impact on the rock-breaking performance, with the increase of ground stress leading to higher rock strength and a 28.56% decrease in rock-breaking performance. However, at ground stresses above 50 MPa, the rock-breaking performance increased by 20%. The horizontal stress difference concentrated the stress on the pore walls and weakened the cementation between mineral particles, resulting in increased roughness and a 58.85% increase in rock-breaking performance with a 25.56% reduction in energy consumption. These findings provide valuable data and technical support for the jet breaking of hard rock in deep mine construction.