期刊文献+

单轴压缩条件下岩石孔-隙相互作用机制细观研究

Mesoscopic study of interaction mechanism between circular hole and fissures in rock under uniaxial compression
分享 导出
摘要 圆孔和裂隙是岩体内部常见的缺陷形态,其破裂孕育演化机制是岩石力学领域研究的重要课题之一。综合采用数字图像相关技术(DIC)、计算机化X射线轴向分层造影(CT)扫描技术、声发射(AE)监测技术,结合颗粒流PFC2D计算数据,构建含孔-隙的类岩石试样并开展单轴压缩试验,探究孔-隙相互作用下试样强度、变形等力学特征及裂纹孕育演化规律。研究表明,(1)峰前声发射事件数相对较少且均匀,而峰后声发射事件数较多,应力降时刚度绝对值越大,声发射事件频数越大;(2)试样破坏产生的宏观裂纹可分为Ⅰ型裂纹(翼型张拉裂纹)和Ⅱ型裂纹(剪切裂纹)两类,Ⅰ型裂纹首先在裂隙端部和圆孔上下端起裂,沿着平行于加载方向扩展,Ⅱ型裂纹主要在圆孔与裂隙内侧之间的岩桥区域和裂隙外侧与试样边界间的区域产生,且与加载方向呈一定夹角扩展;(3)裂纹扩展路径主要分为翼型张拉裂纹扩展和次生共面裂纹扩展两种,加载前期以翼型张拉裂纹扩展为主,加载后期以次生共面裂纹扩展为主;(4)综合采用DIC技术、CT扫描技术、AE监测技术,结合PFC2D计算方法,建立岩体破坏过程中细观力学机制与宏观力学响应的联系,直观准确地揭示岩体表面及内在裂隙孕育演化规律及分布特征。 Circular hole and fissure are common flaws in rock mass;and their crack inoculation and evolution mechanisms have become one of the most important research subjects in the field of rock mechanics. Rock-like specimen containing circular hole and fissures are constructed and subjected to uniaxial compression based on digital image correlation(DIC) technology, computed tomography(CT) scanning technology, acoustic emission(AE) monitoring technology and particle flow code in PFC2D calculation data. Under the interaction between circular hole and fissures, the mechanical characteristics such as strength and deformation and fracture development are investigated in detail. Research results show that:(1) the number of acoustic emission events are relatively small and uniform in pre-peak;but the number of acoustic emission events are large in post-peak;and the greater the absolute value of the stiffness at the time of stress drop, the greater the frequency of acoustic emission events.(2) The macroscopic cracks generated by specimen failure can be classified into two modes, namely mode Ⅰ(tensile crack) and mode Ⅱ(shear crack). The mode Ⅰcrack first initiates from the ends of the fissures and the upper and lower of the circular hole, which is approximately parallel to the loading direction. The mode Ⅱ crack, extending at a certain angle with the loading direction, mainly occurs in the rock bridge area between the circular hole and the inner side of the fissures, and the area between the outer side of the fissures and the boundary of the specimen.(3) There are mainly two kinds of crack propagation paths, i.e. airfoil tensile crack propagation and secondary coplanar crack propagation. Among them, the main crack propagation is the airfoil tensile crack in the early loading stage, and the secondary coplanar crack growth is the main one in the late loading stage.(4) The DIC technology, CT scan technology, AE monitoring technology and PFC2D calculation method are adopted synthetically, which can establish the relationship
作者 伍天华 周喻 王莉 孙金海 赵欢 孙铮 WU Tian-hua;ZHOU Yu;WANG Li;SUN Jin-hai;ZHAO Huan;SUN Zheng(Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mine, University of Science and Technology Beijing, Beijing 100083,China;PowerChina Road Bridge Group Co., Ltd., Beijing 100048, China)
出处 《岩土力学》 CSCD 北大核心 2018年第S2期463-472,共10页 Rock and Soil Mechanics
基金 国家青年科学基金项目(No.51504016) 中央高校基本科研业务费专项项目(No.FRF-BD-17-007A).
关键词 数字图像相关 CT扫描 颗粒流程序 单轴压缩 裂纹扩展 digital image correlation CT scanning particle flow code(PFC) uniaxial compression crack propagation
作者简介 第一作者:伍天华,男,1994 年生,硕士研究生,主要从事采矿工程灾害方面的研究工作。E-mail:thwth1212@163.com;通讯作者:周喻,男,1985 年生,博士,副教授,主要从事矿山岩石力学及数值计算方面的教学与研究工作。E-mail:westboy85@sina.com。
  • 相关文献

相关作者

内容加载中请稍等...

相关机构

内容加载中请稍等...

相关主题

内容加载中请稍等...

浏览历史

内容加载中请稍等...
;
使用帮助 返回顶部 意见反馈