摘要
采用有限元/离散元耦合数值模拟技术分析不同结构面位置条件下深部采动硬岩巷道的裂纹扩展行为、能量演化规律与应力位移分布特征,揭示张拉板裂型破坏与结构面剪切型破坏之间的互动机制。研究结果表明:开挖卸荷产生的板裂化破坏与结构面活化引起的剪切滑移破坏是诱发岩爆的重要原因;结构面与开挖边界的相对距离对巷道围岩稳定性具有显著影响,其临界相对距离(当二者之间的相对距离大于等于某一临界值时,结构面对巷道围岩破坏不产生作用)随结构面长度的增加呈现单调递增趋势;在临界相对距离内,即使结构面之间不发生层间错动和滑移,结构面的存在也会潜在地影响巷道围岩稳定性,这表明以板裂化岩爆为主的破坏模式可以是开挖卸荷效应和结构面效应的综合响应。当最大主应力与结构面位于同一侧时,卸载后模型内动能未出现明显波动和起伏,此时巷道的破坏仅与开挖卸荷效应有关。
The combined finite element method/discrete element method(FEM/DEM)was conducted to investigate the crack propagation behavior,energy evolution law,and displacement distribution of the deep hard tunnel affected by structural plane position during excavation unloading process.The interactive mechanism between slabbing failure induced by unloading effect and shearing failure activated by structural effect was revealed.The results indicate that the slabbing failure induced by excavation unloading effect and sliding caused by activation of structural plane are the main reasons for the rockburst.The relative distance of the weak planes to the excavation boundaries strongly impacts tunnel stability and the critical distance where weak planes do not affect the tunnel wall increases with increasing joint persistence.The presence of weak planes can potentially affect tunnel failure within the critical relative distance,even when there is no relative shearing and sliding.This implies that the failure pattern dominated by slabbing or strainburst can be an integrated response to the effects of excavation unloading and weak planes.The tunnel failure is only induced by eacavation unloaidng effect when the maximum principal stress and multiple structural planes are on the same side.Under such a condition,there is no obvious surge and fluctuation for kinetic energy after the ternimation of unloading point.
作者
冯帆
赵兴东
陈绍杰
李夕兵
李地元
黄万朋
FENG Fan;ZHAO Xingdong;CHEN Shaojie;LI Xibing;LI Diyuan;HUANG Wanpeng(College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China;School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining&Technology(Beijing),Beijing 100083,China;School of Resources and Safety Engineering,Central South University,Changsha 410083,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2021年第8期2588-2600,共13页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(52004143,51774194)
中国博士后科学基金资助项目(2020M670781)
中国矿业大学深部岩土力学与地下工程国家重点实验室开放基金资助项目(SKLGDUEK2021)。
关键词
深部硬岩
有限元/离散元
破坏模式
结构面位置
开挖卸荷
能量演化
岩爆
deep hard rock
FEM/DEM
failure mode
structural plane position
excavation unloading
energy evolution
rockburst
