煤矿巷道顶板宏观单裂隙的力学行为及影响分析

(1.西安科技大学 能源学院,陕西 西安 7100541; 2.内蒙古科技大学 矿业与煤炭学院,内蒙古 包头 014010; 3.西安科技大学 西部矿井开采及灾害防治教育部重点实验室,陕西 西安 710054)

宏观裂隙; 张开率; 切向滑移度; 连通率; 力学行为; 顶板

Influential analysis and mechanical behavior of macroscopic single fracture in roadway roof
WANG Chao1,2,WU Yong-ping1,3,CHEN Shi-jiang1,ZHENG Wen-xiang1

(1.College of Energy Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.School of Mining and Coal Engineering,Inner Mongolia University of Science and Technology,Baotou 014010,China; 3.Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi'an University of Science and Technology,Xi'an 710054,China)

macro fracture; openning rate; tangential slip rate; connectivity rate; mechanical behavior; roof

DOI: 10.13800/j.cnki.xakjdxxb.2019.0206

备注

宏观尺度裂隙对岩体完整性和强度影响显著,其赋存形态亦影响巷道顶板的稳定。为了揭示裂隙赋存形态对巷道顶板的影响规律,以“张开率”和“切向滑移度”来表征裂隙(层理)的行为状态,利用FLAC3D中Interface命令构建裂隙(层理),分析了不同裂隙倾角和连通率的单裂隙条件下巷道开挖后顶板裂隙的力学行为、位移、应力及其分布。结果 表明:裂隙倾角及连通率影响裂隙开裂宽度及范围、裂隙(层理)剪切位移及范围、层理剪切滑移区分布; 裂隙张开率和切向滑移度均与连通率呈“双曲线”关系; 裂隙倾角对裂隙的形态与演化有较大影响; 顶板下沉与裂隙倾角和连通率呈现单调增(减)关系。因此,控制顶板下沉能有效控制巷道顶板裂隙的扩展与连通,亦有助于预防顶板离层和滑移。

The macro fracture has a significant impact on the integrity and strength of rock mass and also affects the stability of roadway roof.In order to reveal the influential law of the fracture on the roadway roof,the behaviour state of fracture(bedding)was characterized by the “opening rate” and “tangential slip rate”,and the crack(bedding)was constructed by the interface command in FLAC3D.The mechanical behaviour,displacement,stress and its distribution were analysed under different fracture angle and connectivity rate of the single fracture.The results show that the crack width and range,the shear displacement and range of the fracture(bedding)and the distribution of the shear slip region in the bedding are affected by the fracture angle and connectivity rate.The “hyperbolic relationship” is shown at both the fracture connectivity rate and opening rate and the fracture connectivity rate and tangential slip rate.The fracture angle has a great influence on the fracture behavior and evolution.The roof subsidence,fracture angle and connectivity rate are monotonically increased or decreased.Therefore,it is effective to control the extension and connectivity of roof crack by controling roof subsidence,which also helps to prevent roof separation and slippage.