柱状节理玄武岩洞段开挖支护施工技术——以白鹤滩水电站导流洞为例

白鹤滩水电站导流洞工程开挖断面大、地应力水平较高,柱状节理玄武岩分布规模大、岩体特点突出、不良地质现象频发、开挖支护施工难度大。在柱状节理玄武岩洞段施工过程中,通过对开挖支护方法及支护参数不断地改进,取得了良好的效果,保证了施工人员设备安全和开挖施工节点目标的顺利实现。

Excavation Support Technology for Diversion Tunnel Construction in Basalts with Columnar Joints in Baihetan Hydropower Station

Excavation support in the construction of diversion tunnel in Baihetan hydropower station is of great difficulties due to the poor geological conditions of large excavation section,high in- situ ground stress,wide distribution of basalts with columnar joints,etc. To ensure the safety of tunnel excavation,some technical improvements on the support methods and support parameters are adopted. Satisfying results are obtained in practice,which guarantees the safety of workers and equipments and the schedule of excavation.