【摘要】 为了研究结构面对中等地应力区地下厂房开挖过程中应力调整以及围岩变形破坏的影响,以某抽水蓄能电站地下厂房为研究对象,采用离散元软件3DEC对其开挖过程进行仿真计算.研究表明:在开挖断面不大时,掌子面附近的结构面会阻挡围岩应力向深部的调整,加剧拱脚处的应力集中程度,使围岩以应力型破坏为主;当开挖断面增大,围岩卸荷松弛明显,结构面控制型破坏将逐渐占优;用3DEC模拟出的陡倾型结构面的张开是围岩位移产生的主要原因,且其张开位移受前几期的开挖影响较大.研究成果可为类似陡倾角大跨度地下工程开挖的稳定性分析及支护设计提供借鉴.更多还原

【Abstract】 In order to study the influence of the structure on the stress adjustment and the surrounding rock deformation and failure during the excavation of the underground powerhouse in the middle initial stress, the underground powerhouse of a pumped storage power station was taken as the research object, with discrete element software 3 DEC used to simulate the excavation process. The study shows that when the excavation section is small, the structural surface near the excavation face will block the adjustment of surrounding rock stress and increase stress concentration at the arch foot, mainly leading to stress-dominated failures on the surrounding rock. When the excavation section is enlarged, stress relaxation of surrounding rock is obvious and the controlled failure of the structure plane will gradually dominate. The structural plane opening simulated by 3 DEC is the main cause of surrounding rock displacement, and its opening displacement is greatly affected by the excavation in previous periods. The results could provide an important reference for stability analysis and design support of similar steeply dipped rock strata of large span underground projects.更多还原