不同冲击速度条件下矩形巷道围岩变形-开裂过程数值模拟  

Numerical simulation on the deformation-cracking process of rectangular tunnel surrounding rock under different impact velocities

作　　者：王学滨 田锋[2] 白雪元 郭翔 WANG Xuebin;TIAN Feng;BAI Xueyuan;GUO Xiang(Institute of Computational Mechanics,Liaoning Technical University,Fuxin 123000,China;College of Mechanics and Engineering,Liaoning Technical University,Fuxin 123000,China)

机构地区：[1]辽宁工程技术大学计算力学研究所,辽宁阜新123000 [2]辽宁工程技术大学力学与工程学院,辽宁阜新123000

出　　处：《振动与冲击》2020年第14期94-101,108,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(51574144);辽宁省百千万人才工程项目(2017)。

摘　　要：利用自主开发的拉格朗日元与变形体离散元耦合的连续-非连续方法,开展了不同冲击速度条件下矩形巷道围岩变形-开裂过程的数值模拟研究。当岩石单元的应力满足剪切开裂判据时,考虑了应力脆性跌落效应,在此过程中,围压保持不变。为了检验该方法的正确性,开展了单轴压缩条件下岩样变形-开裂过程的数值模拟研究。针对矩形巷道围岩的计算表明:①冲击速度低时载荷-位移曲线呈单峰特点;冲击速度高时载荷-位移曲线呈多峰特点;②冲击速度低时围岩的开裂呈渐进性特点;冲击速度高时围岩的开裂呈间歇性特点,这与在冲击过程中围岩中过去形成的一种较为稳定的结构(拱)被打破,并在其外围形成了新的稳定结构(拱)有关;③在模型相同垂直方向位移时,冲击速度低时围岩两帮的开裂深度较大,这说明冲击速度低时应力的传递较为均匀,冲击速度低时的结果(例如,V形坑内岩石碎块涌入巷道)与围岩的片帮类似;冲击速度高时的结果(例如,岩石碎块的弹射现象)与岩爆类似。Using a continuum-discontunuum method where the Lagrangian element method and deformational discrete element method were combined, the deformation-cracking process of rectangular tunnel surrounding rock under different impact velocities was modeled numerically. When the stresses in rock elements satisfy the shear failure criterion, the brittle drop effect of the stress in the condition of keeping the confining pressure unchanged was considered. To validate the present method, the deformation-cracking process of a rock specimen in uniaxial compression was modeled numerically. It is found from the results of rectangular tunnel surrounding rock that: ① at lower impact velocities, the load-displacement curve of the surrounding rock exhibits a single peak, while at higher impact velocities it exhibits several peaks;② at lower impact velocities, the failure of the surrounding rock is progressive, while it is intermittent at higher impact velocities, which is related to the fact that the previous stable arch shaped structure fails during the impact process and turns to form a new larger stable arch structure;③ under the same vertical displacement of the surrounding rock, the cracking depth at two sides of the surrounding rock is larger at lower impact velocities than at higher impact velocities, indicating a relatively uniform stress propagation at lower impact velocities. The damage type at lower impact velocities, for example, rock blocks in V-shape notches are squeezed into the tunnel is similar to the rib spalling of the surrounding rock at two sides, while that at higher impact velocities, for example, ejection of rock blocks is similar to rockbursts.

关 键 词：巷道 围岩 开裂 冲击速度 位移 载荷 数值模拟 

分 类 号：TD32[矿业工程—矿井建设] O347[理学—固体力学]