低围压双向压缩条件下竖直裂纹扩展机制研究  

Study on the Mechanism of Vertical Crack Propagation Under Low Confining Pressure with Biaxial Compression

作　　者：王家豪 汪学清[1] 高阳[2] 胡明明[2] WANG Jiahao;WANG Xueqing;GAO Yang;HU Mingming(School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;Institute of Rock and Soil Mechanics,Chinese Academy of Science,Wuhan,Hubei 430071,China)

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]中国科学院武汉岩土力学研究所,湖北武汉430071

出　　处：《矿业研究与开发》2024年第1期104-111,共8页Mining Research and Development

基　　金：国家自然科学基金项目(41941018,52009128).

摘　　要：为研究地下洞室开挖等岩石工程中双向压缩应力状态下的岩体裂纹扩展机制,以低围压三向受压或单轴压缩条件下含竖直裂纹的岩体试样为研究对象,通过数值模拟的方式分析不同泊松比μ和裂纹迹长a条件下远场轴向压应力和裂纹尖端应力的分布规律。基于叠加原理得到双向压缩条件下竖直裂纹/翼裂纹尖端近场应力的表达式,并推导出该应力状态下裂纹岩体试样的应力强度因子及裂纹扩展方向。结果表明:存在远场轴向压应力时,泊松比μ和裂纹迹长a对裂纹尖端应力分布规律有明显影响。裂纹尖端应力σxx与平行于裂纹面的轴向压应力σn的比值与泊松比μ成一次函数关系,与裂纹迹长a成三次函数关系。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 ratiosμand 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 ratioμand crack trace length ahave a significant effect on the stress distribution at the crack tip when there is far-field axial compressive stress.The ratio of theσxxstress at the crack tip to the axial compressive stressσnparallel to the crack surface has a linear function relationship with the Poisson's ratioμand a cubic function relationship with the crack trace length a.

关 键 词：双向压缩应力 远场轴向压应力 近场应力 泊松比 裂纹迹长 

分 类 号：TD313[矿业工程—矿井建设] TU45[建筑科学—岩土工程]