摘要
脆性岩石断裂失稳一直是岩石力学领域科学研究和工程应用的热点。为研究层理方向对含预制裂纹页岩断裂特性的影响,对不同断裂模式(以预制裂纹角度α表示)和含不同层理倾角(β)的页岩开展半圆盘三点弯曲静态加载破坏试验,揭示了层理方向对试件峰值载荷、断裂特性及临界起裂角的影响规律。结果表明:试件强度、断裂韧度和破坏模式随着断裂模式和层理倾角的改变而表现出差异性,裂纹扩展方向和试件断裂模式受层理倾角影响,当β=0°时,试件裂纹均沿着贯穿层理的方向扩展,随着β的增大,试件裂纹由垂直于层理扩展逐渐偏向沿层理方向扩展;当断裂模式相同时,临界起裂角θ_(m)随着β的增大而普遍增大,且随着断裂模式的改变,即α由0°变化为54°,β对θ_(m)的影响程度加剧;最大切应力(MTS)断裂准则可作为试件起裂的判断准则。
Fracture instability of brittle rocks has always been a hot topic in scientific research and engineering application in the field of rock mechanics.In order to study the influence of bedding direction on the fracture characteristics of shale with a prefabricated crack,a three-point bending static loading failure test was conducted on half-disk shale specimens with different fracture modes(represented by prefabricated crack angles α)and different bedding plane angles β.Based on the test results,the influence of bedding direction on the peak load,fracture characteristics,and critical fracture angle of the specimens were revealed.The test results show that the strength,fracture toughness,and failure mode of the specimens will vary with α and β,and the crack expansion direction and the failure mode of the specimens are affected by β.To be specific,when β=O°,the crack expands in the direction running through the bedding plane.As β increases,the crack gradually expands from the direction perpendicular to the bedding plane to the direction along the bedding plane.Meanwhile,under the same fracture mode,the critical fracture angle m generally grows with the increase of β;as the fracture mode alters,i.e.,as α increases from O° to 54°,the influence of β on 3m is enhanced.The maximum tangential stress(MTS)fracture criterion can be used as a criterion for determining the initiation of cracking in specimens.
作者
李勇
胡双杰
陈结
桂辉高
孙传猛
LI Yong;HU Shuangjie;CHEN Jie;GUI Huigao;SUN Chuanmeng(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China;State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument,North University of China,Taiyuan,Shanxi 030051,China)
出处
《采矿与安全工程学报》
北大核心
2025年第3期684-695,共12页
Journal of Mining & Safety Engineering
基金
国家重点研发计划青年科学家项目(2022YFC2905700)
重庆市技术创新与应用发展专项重点项目(CSTB2024TIAD-KPX0102)
煤矿灾害动力学与控制全国重点实验室开放基金项目(2011DA105287-FW202408)
中央高校基本科研业务费项目(2024CDJGF-013)。
关键词
层理方向
断裂模式
三点弯曲试验
裂纹扩展
断裂特性
bedding direction
fracture mode
three-point bending test
crack propagation
fracture characteristics
