摘要
为研究岩体工程中矿柱型岩爆的能量释放和碎块抛射速度,制成3种岩石材料的矿柱试验模型,对其进行单轴压缩试验并用高速摄像机拍摄碎块的抛射过程,实测了碎块的抛射速度。根据Griffith能量释放理论,运用有限元软件在平面应力和平面应变条件下计算试验模型破坏前后瞬时应变能的改变量(释放量),考虑部分能量耗散后运用能量守恒原理计算碎块的理论抛射速度。研究结果表明,在单轴压缩试验中红砂岩、石岛红花岗岩和白麻花岗岩的抗压强度、弹性模量依次增大,岩爆倾向性增强,其在矿柱模型破坏中3种材料的能量释放量和碎块抛射速度也依次增大;宽柱模型破坏程度比窄柱模型剧烈;平面应变模型(现场)比平面应力模型(试验)破坏时释放更多能量,即岩石的强度、弹性模量和尺寸型式决定岩爆破坏剧烈程度;矿柱岩爆模型试验中碎块的理论抛射速度与实测速度值基本接近。在不考虑尺寸效应的情况下证明了在相同应力下具有比例尺寸关系的工程体与模型发生破坏时的抛射速度基本相同。
In order to study energy release and ejection velocities of rock fragments induced by pillar rockburst in rock mass engineering, pillar model specimens are designed and prepared with three different types of rock materials. The ejection processes of rock fragments in failure are recorded by the high-speed camera in uniaxial compression tests;and the ejection velocities of rock fragments are calculated with experimental data. Based on Griffith’ energy release theory, the released energy in failure of test models are calculated by ANSYS finite element software under both plane stress and plane strain;and the theoretical ejection velocities of fragments are calculated by the principle of conservation of energy after removing a certain percentage of energy dissipation. The results show that the compressive strength, elastic modulus, and rockburst proneness, as well as the released energy and ejection velocity of fragments increase sequentially(following the sequence of red sandstone, shidao red granite and camellia white granite). The failure degree is severer for the pillars with the larger width. The energy release under the plane strain condition(which is closer to the pillars in the field engineering) is greater than that under the plane stress condition(which is closer to the tests in this study). Therefore, the compressive strength, elastic modulus of rock materials and the shape and size of rock structure determine the disaster degree of pillar rockburst. The theoretical ejection velocities of fragments are basically close to the measured velocities in model tests on pillar rockburst. Without considering the size effect, it is proved that the ejection velocity occurred in the large-scale model(engineering scale) is basically equal to that in the small-scale model(test scale) under the same stress condition.
作者
王之东
黎立云
陈滔
刘兵权
WANG Zhi-dong;LI Li-yun;CHEN Tao;LIU Bing-quan(School of Mechanics and Civil Engineering, China University of Mining and Technology(Beijing), Beijing 100083, China;State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology( Beijing), Beijing 100083, China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2018年第S2期177-185,20,共10页
Rock and Soil Mechanics
基金
国家重点基础研究发展规划(973)项目(No.2010CB226802,No.2011CB201201)
国家自然科学基金项目(No.41072242)~~
关键词
矿柱型岩爆
模型试验
有限元计算
能量释放
抛射速度
pillar rockburst
model test
finite element calculation
energy release
ejection velocity
作者简介
第一作者:王之东,男,1987 年生,博士研究生,主要从事岩石断裂力学与动力灾害防治的研究工作。E-mail: wangzhidong1116@126.com;通信作者:黎立云,女,1959 年生,博士,教授,主要从事岩石断裂力学与能量理论的研究工作。E-mail: lly@cumtb.edu.cn。
