摘要
开展贯通裂隙岩样在法向卸荷下的压剪破坏研究,有助于更好地理解岩体裂隙在卸荷条件下的失稳特征。对单裂隙贯通岩样开展剪切应力峰前一系列法向卸荷破坏试验,分析了法向卸荷下试样裂隙的变形及能量演化规律。结果表明,法向卸荷下裂隙压剪失稳时的法向应力大于常规直剪试验的对应值,裂隙的抗剪能力减弱;剪切位移随法向应力减小而增大;卸荷变形比K随裂隙轮廓面积比Rs的增加而增大;卸荷过程中总变形能U0由减小转变为增加的现象可用于预测岩石裂隙卸荷失稳。研究结果对理解贯通裂隙岩体压剪卸荷失稳破坏具有一定参考意义。
The instability characteristics of fractured rock masses under unloading conditions can be better understood depending on compression-shear failure experiments on fractured rock samples.In this paper,a series of normal unloading tests on rock specimen with a single fracture were conducted under pre-peak shear stress.The deformation of rock samples and energy evolution were analyzed.The results show that the normal stresses at failure under normal unloading condition are larger than those of direct shear loading test,and the shear resistance of fractures decreases.The shear displacement increases with the decrease in normal stress.The normal deformation ratios(K)under normal unloading conditions increase with the increase in the contour area ratios(Rs)of rock fracture surfaces.The total energy decreases at first,and then increases during normal unloading process.This phenomena can be used to predict the imminent unloading instability of fractured rock masses.The results in this paper have certain references for understanding the unloading instability failure of fractured rock masses.
作者
翟明磊
郭保华
王辰霖
焦峰
ZHAI Ming-lei;GUO Bao-hua;WANG Chen-lin;JIAOFeng(School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo,Henan454000,China;Synergism Innovative Center of Coal Safety Production in Henan Province,Jiaozuo,Henan454000China;College of Resources and Environmental Sciences,Chongqing University,Chongqing400044,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第A01期217-223,230,共8页
Rock and Soil Mechanics
基金
国家自然科学基金项目（No.51109076）~~
关键词
贯通裂隙
法向卸荷
变形特征
能量演化
penetrated fracture
normal unloading
deformation characteristics
energy evolution
