摘要
在类岩石材料试验的基础上,建立颗粒流(PFC)数值模型,研究不同围压下断续节理岩体的破坏机制。对节理倾角α为25°,60°和90°的岩体,在围压σ3为0,1,4,7和10MPa下进行数值压缩试验,分析不同围压下断续节理岩体的力学响应、破坏形态、裂纹发展、能量演变过程及裂纹初始应力的变化。研究结果表明:围压显著影响岩体的变形和强度,然而节理岩体的平均弹性模量并不受围压的影响。岩体的破坏形态受到节理和围压共同控制:低围压下,节理倾角决定了岩体的破坏形态;随着围压的升高,岩体的破坏形态更多表现为形成剪切破坏面,节理的影响变小。围压抑制了裂隙尖端翼裂纹的扩展,高围压下岩体内裂纹分布更均匀,岩体破坏需产生更多的裂纹。随着围压的升高,岩体内各类能量的总和及比例将产生变化。裂纹初始应力随着围压的增加而单调递增并为非线性关系。
According to uniaxial compressive test of rock-like materials, particle flow code（PFC） numerical model was created, and failure mechanism of discontinuous joint rock mass under different confining pressures was studied.Numerical compressive tests of specimens with joint inclination（i.e., 25°, 60° and 90°） under different confining pressures（i.e., 0, 1, 4, 7 as well as 10 MPa） were performed and the effect of the confining pressure on mechanics response, failure shape, cracks development and energy transform to the discontinuous joint rock mass were studied. The results show that confining pressure has a marked influence on deformation and strength of discontinuous joint rock mass,but the average modulus is not significantly affected. Both joint inclination and confining pressure can influence rock specimen＇s failure shapes. With lower confining pressure, joint inclination highly affects specimen＇s failure shapes, or shear band is formed and joint has little implication. As the confining pressure goes up, the development of cracks is constrained and cracks advanced process is extended, and finally, more cracks are created. When the confining pressure is changed, the total and proportion of diverse types of energy will vary. With the increase of the confining pressure increasing, the crack initiation stress rises nonlinearly.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2014年第10期3536-3543,共8页
Journal of Central South University:Science and Technology
基金
国家科技部科研院所专项基金资助项目(2011EG122210)
湖南省自然科学基金资助项目(11JJ3051)
湖南省教育厅资助科研项目(13C307)
河南省瓦斯地质与瓦斯治理重点实验室--省部共建国家重点实验室培育基地开放基金资助项目(WS2013A07)
煤矿安全开采技术湖南省重点实验室开放基金资助项目(201005)~~
关键词
岩石力学
围压
节理岩体
颗粒流
rock mechanics
confining pressure
jointed rock mass
particle flow code
