根据锦屏II级水电站地下隧洞的地质条件、现场试验、数值分析和支护设计与施工全过程,建立深埋硬岩隧洞围岩的破坏模式分类方法。该分类方法依据支护要求和控制因素将深埋硬岩隧洞的破坏现象分为3个大类、9种典型破坏模式,分析各种破坏模式的发生机制、表现形态以及调控策略,重点讨论岩爆的机制以及相应的调控策略。应用该分类方法对锦屏II级水电站地下隧洞围岩的破坏模式进行识别、机制分析,相应的调控措施也得到采纳。工程实践表明,该分类方法全面、实用,为现场设计、地质和施工工程师等在深埋硬岩条件下进行隧洞开挖和支护设计优化提供具体指导方针。
According to the geological conditions,field test,numerical analysis and the entire process of supporting design and construction of tunnels in Jinping II hydropower station,a classification method for failure modes of surrounding rock of deep tunnel in hard rock is established.All of failure phenomena are divided into 3 categories and 9 typical failure modes by the proposed method respectively based on demands of supporting and controlling factors.Furthermore,failure mechanisms and manifestations are analyzed;and controlling measures are provided.Specially,the mechanisms and corresponding controlling measures of rockbursts are discussed.The classification method is applied to identify and analyze various kinds of failure modes,all of which are revealed during excavation of tunnels in Jinping II hydropower station.The recommended controlling measures are adopted referring to the failure modes.The engineering practice indicates that the classification method is comprehensive and practical,which provides an effective way for on-site designers,geologists and constructors to optimize excavation and supporting design of deep tunnel in hard rock.