摘要
为揭示不同倾角硬岩非连续结构面剪切破裂机制,开展了常法向应力下8种不同节理角度的非连续结构面剪切试验及同步声发射监测,并基于声发射信号主频实现了破坏过程中破裂程度的定量分析,结合剪切破坏强度、剪切破坏结构和破裂程度演化过程,研究了硬岩非连续结构面剪切破坏特征。结果表明:非连续结构面破坏阶段Ⅰ的荷载峰值SR1整体变化趋势呈现水平横置S型,阶段Ⅱ的峰值荷载SR2呈现节理角度对称分布,当节理角度为正向小角度时,SR1>SR2,而负向角度和正向大角度时,均为SR2>SR1;其破坏结构可以分为平面破坏结构、锯齿型破坏结构和块体破坏结构3种,3种破坏结构实际由4种裂纹扩展方式决定;节理角度对非连续结构面剪切过程中大尺度破坏的出现具有控制作用,在节理角度较大下非连续结构面在破坏阶段Ⅰ和破坏阶段Ⅱ均发生较大尺度的破坏,而节理角度较小时非连续结构面仅在破坏阶段Ⅰ发生大尺度破坏;非连续结构面的破坏过程可以划分为4类,随着节理角度的增加,破坏过程由单峰−突发型发展为双峰平稳−平稳型,进而为双峰突发−平稳型,最终为双峰突发−突发型。
In order to deeply understand the shear failure mechanism of intermittent joints,shear tests and acoustic emission monitoring of intermittent joints with different joint angles are carried out.Based on the dominant frequency of acoustic emission signal,the quantitative analysis of fracture degree in the failure process is realized.By combining the shear failure strength,shear failure structures and the evolution process of fracture degree,the shear failure characteristics of intermittent joints are studied.The results show that the variation trend of SR1 at stage I of intermittent joints presents horizontal transverse S-shape,and SR2 presents symmetrical joint angle distribution.When the joint angle is positive small angle,SR1 is greater than SR2,while when the negative angle and positive large angle,SR2 is greater than SR1.The failure structures of intermittent joints can be divided into plane failure structure,zigzag failure structure and block failure structure,three failure structures are actually determined by four crack propagation modes.Joint angle controls the occurrence of large-scale failure,intermittent joints will have large-scale failure in stage I and stage II when subjected to large joint angle.However,the large-scale failure only occurs in stage I when the joint angle is small.The failure process of intermittent joints can be divided into four categories.With the increase of joint angle,the failure process develops from"unimodal abrupt"to"bimodal stable-stable",then to"bimodal abrupt-stable",and finally to"bimodal abrupt-abrupt".
作者
刘畅
江权
阮航
李超毅
杜三林
LIU Chang;JIANG Quan;RUAN Hang;LI Chao-yi;DU San-lin(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;Huaneng Tibet Hydropower Safety Engineering Technology Research Center,Nyingchi,Tibet 860061,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第S01期173-185,共13页
Rock and Soil Mechanics
基金
国家自然科学基金(No.52325905)。
关键词
非连续结构面
剪切破坏
破坏结构
信号主频
破裂比例
intermittent joints
shear failure
failure structure
dominant frequency
fracture percent
作者简介
第一作者:刘畅,男,1993年生,博士研究生,主要从事岩石结构面剪切破裂特征等方面的研究工作。E-mail:liuchang164@mails.ucas.ac.cn;通讯作者:江权,男,1978年生,博士,研究员,主要从事地下工程物理与数值模拟、大型洞室群稳定性分析、工程地质灾害治理等方面的研究工作。E-mail:qjiang@whrsm.ac.cn
