摘要
基于空间局部化视角研究分区破裂化的发生机制。采用三维非均质应变软化模型,在逐步开挖和不同轴压与侧压之比条件下研究了马蹄形(U形)巷道围岩不同剖面和测线上剪切应变增量的分布特征。结果表明:U形巷道围岩的分区破裂化呈圆环形;分区破裂化可出在现掌子面的前、后方;在掌子面前方,随着远离掌子面,分区破裂化有所减弱,直至消失;轴压与侧压之比越大,分区破裂化越明显;在垂直于巷道轴线的不同平面上,分区破裂化有所不同,这与不同剪切带的特征不同及发育不同有关;共轭剪切带的出现,会使分区破裂化变得复杂。启动于巷道表面的空间圆锥剪切面的充分发展产生了分区破裂化。
The mechanism of zonal disintegration is studied from the viewpoint of spatial strain localization.Using a three-dimensional heterogeneous strain-softening model,we investigate distributions of shear strain increments at different planes and monitored lines of the surrounding rock of a horseshoe(U-shaped)tunnel under progressive excavation and different ratios of axial pressure to he lateral pressure.We find that the fractured zones are annular in the surrounding rock of the U-shaped tunnel;prior to and beyond the heading of the tunnel,the zonal disintegration can be found;prior to the heading of the tunnel,the zonal disintegration becomes less apparent until it disappears with an increase of the distance from the heading;higher ratio of the axial pressure to the lateral pressure leads to more apparent zonal disintegration;at different planes orthogonal to the tunnel axis,the zonal disintegration is different,which is related to the different shear band inclination angles and their developing degrees;conjugate shear bands lead to the complex zonal disintegration.A full development of spatial cone-shaped shear planes originated from the tunnel surface results in the zonal disintegration.
作者
王学滨
马冰
张智慧
吕进国
WANG Xuebin;MA Bing;ZHANG Zhihui;LV Jinguo(Institute of Computational Mechanics,Liaoning Technical University,Fuxin 123000,China;College of Mechanics and Engineering,Liaoning Technical University,Fuxin 123000,China;Research Institute for Technology&Equipment of Coal Mine Safety,Liaoning Technical University,Fuxin 123000,China)
出处
《防灾减灾工程学报》
CSCD
北大核心
2019年第5期827-834,共8页
Journal of Disaster Prevention and Mitigation Engineering
基金
国家自然科学基金项目（51574144）
辽宁省高等学校优秀人才支持计划（LR2015029）
高等学校博士点专项科研基金（20132121110006）资助
关键词
分区破裂化
三维模型
非均质应变软化
轴压
侧压
逐步开挖
马蹄形巷道
数值模拟
zonal disintegration
three-dimensional model
heterogeneous strain-softening
axial pressure
lateral pressure
progressive excavation
U-shaped tunnel
numerical simulation
