深埋断层节理段导流隧洞围岩稳定性分析

Analysis on Surrounding Rock Stability of Diversion Tunnel in Joint Section of Deep-buried Fault

摘要:

西南某水电站导流隧洞K1+350～400桩号发育F13断层等多条节理，埋深大，地应力较高，地质条件复杂。运用三维离散单元软件3DEC对其进行数值模拟，并结合现场监测数据对其围岩稳定性进行分析。结果表明，该段围岩稳定性主要受结构面控制，F13断层下盘右拱肩掉块较多，位移较大，支护后导流隧洞围岩稳定性得到加强，支护效果较好。

关键词:导流隧洞;断层;开挖支护;围岩稳定;3DEC

Abstract:

Multiple joints such as fault F13 developed in K1 350～400 of a diversion tunnel of hydropower station in the southwest, which was deep-buried with high crustal stress and complex geological conditions. Using three-dimensional discrete element software 3DEC, the numerical simulation on the diversion tunnel is conducted combining with field monitoring data to analyze the stability of surrounding rock. The results show that the stability of surrounding rock is mainly controlled by the structural plane. There are many fall-blocks at the lower right spandrel with larger displacement. After being supported, the surrounding rock stability of the diversion tunnel is strengthened.

Key words:diversion tunnel; fault; excavation and support; stability of surrounding rock; 3DEC