摘要
为研究含锯齿状结构面岩体的剪切力学性质及其弱化行为,采用自主研发的岩石压剪伺服试验系统,对含有不同起伏角锯齿结构面的类岩石试件开展了不同剪切位移的直剪试验。试验结果表明:当结构面锯齿起伏角为15°时,结构面的剪应力演化曲线呈“波浪形”,当起伏角为30°和45°时,剪应力演化曲线呈“峰值型”且45°起伏角结构面的剪应力演化有明显的双峰值现象,起伏角越大,峰值剪应力越大;当起伏角为15°时,结构面的弱化模式为爬坡磨损,起伏角为30°时,结构面弱化则以切齿-充填为主,而当起伏角为45°时,结构面在前期以切齿破坏为主,后期以滑动磨损为主;结构面的损伤系数R随着剪切位移的增加而逐渐增大,并且起伏角越大,R值越大,结构面的弱化程度越大,结构面在剪切位移为5 mm处的弱化率均在50%以上。研究成果可为工程岩体稳定性分析提供参考。
In order to study shear mechanical properties and weakening behaviors of rock mass with sawtooth structural plane,direct shear tests on rock-like specimens with different fluctuation angles of sawtooth structural planes under different shear displacements were carried out using a self-developed rock compression-shear servo test system.The experimental results are concluded as follows.Firstly,the shear stress evolution curve is"wavy"when the structural plane fluctuation angle is 15°.When the fluctuation angle is 30°and 45°,the shear stress evolution curve shows a"peak"type.And the shear stress evolution of the structural plane with 45°fluctuation angle shows an obvious double-peak phenomenon.With the increase of the fluctuation angle,the peak shear stress shows an increasing trend.Secondly,when the fluctuation angle is 15°,the weakening mode of the structural plane is climbing wear.When the fluctuation angle is 30°,the weakening mode of the structural plane is mainly cutting and flling,and when the fluctuation angle is 45°,the structural plane is mainly weaken as cutting damage in the early stage and sliding wear in the late stage.Thirdly,the damage coefficient R of structural plane gradually increases with the increase of shear displacement,and the larger the fluctuation angle,the larger the value of R,indicating the deeper the weakening degree.The weakening rate of the structural plane at the shear displacement of 5 mm is all above 50%.The research results can provide a reference for stability analysis of engineering rock mass.
作者
许江
何美鑫
彭守建
焦峰
张心睿
XU Jiang;HE Meixin;PENG Shoujian;JIAO Feng;ZHANG Xinrui(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 40o044,China;State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam,Chongqing University,Chongqing 400044,China)
出处
《矿业研究与开发》
CAS
北大核心
2023年第12期124-130,共7页
Mining Research and Development
基金
国家自然科学基金项目(51874055,52074047)。
关键词
锯齿状结构面
起伏角
剪切位移
弱化模式
损伤系数
Sawtooth structural plane
Fluctuation angle
Shear displacement
Weakening mode
Damage coefficien
