Study on the Mechanism of Vertical Crack Propagation Under Low Confining Pressure with Biaxial Compression
In order to study the crack propagation mechanism of rock mass under biaxial compressive stress in rock engineering such as underground cavern excavation,taking the rock mass specimens with vertical cracks under low confining pressure with triaxial compression or uniaxial compression as the research object,the distribution laws of far-field axial compressive stress and crack tip stress under different Poisson's ratios μ and crack trace length a were analyzed by numerical simulation.Based on the superposition principle,the expression of the near-field stress at the tip of the vertical crack or wing crack under biaxial compression was obtained.And the stress intensity factor and crack propagation direction of the cracked rock mass specimen under this stress state were derived.The results show that Poisson's ratio μ and crack trace length a have a significant effect on the stress distribution at the crack tip when there is far-field axial compressive stress.The ratio of the σxx stress at the crack tip to the axial compressive stress σn parallel to the crack surface has a linear function relationship with the Poisson's ratio μ and a cubic function relationship with the crack trace length a.
万方数据
维普
