关键词: 峰值应力　不等值围压　数值模拟　分形维数　爆破损伤

Abstract: The deep high stress condition is an important factor affecting the blasting effect of rock mass. It is of guiding
significance to understand the rock breaking mechanism of the coupling effect of three-way non-equivalent confining pressure
and blasting load for deep mining. Based on the self-designed triaxial hydraulic loading rock blasting test device,considering
the influence of axial pressure and confining pressure respectively,the blasting test under three-dimensional non-equivalent
confining pressure is carried out. Combined with the propagation law of explosion stress wave and explosion energy,the parameters
such as the number,morphology and distribution of blast-induced cracks in the specimen,the radius of the crushing zone,
the distance from the bottom and the distance from the edge were analyzed. The test results show that the propagation length
and propagation angle of the blasting crack are affected by the confining pressure. The confining pressure will inhibit the rock
blasting failure,and the blasting parameters will be significantly reduced compared with the case without confining pressure.
When the applied pressure is perpendicular to the crack propagation direction,the generation and propagation of blast-induced
cracks can be effectively suppressed. The finite element analysis software LS-DYNA was used to analyze the effective stress,radial
peak stress,tangential peak stress and damage range during the blasting process of rock mass under three-way unequal
pressure. The results show that the rock mass failure is mainly affected by the tangential tensile stress. The compressive stress
perpendicular to the crack propagation direction can effectively suppress the tensile stress of the crack,thereby inhibiting the
length,number and angle of the crack propagation,and constraining the internal damage of the rock mass.

Key words: peak stress,non-equivalent confining pressure,numerical simulation,fractal dimension,blasting damage