隧洞蚀变岩层洞段开挖支护施工技术研究与实践——以硬梁包水电站引水隧洞为例

Research and Practice of Excavation and Support Technique for Tunnel Section in Altered Rock Layer:Taking Headrace Tunnel of Yingliangbao Hydropower Station as an Example

硬梁包水电站引水隧洞工程围岩存在多种不同辉绿岩脉蚀变问题,施工过程中穿越蚀变岩层时极易发生急剧变形、塌方、涌突水等工程地质问题,极大程度地影响工程施工。针对此问题,在施工过程中采取了一系列处理措施,有效的控制住了塌方等地质灾害影响,极大程度地保障了施工安全和进度。详述了针对引水隧洞蚀变岩层采取的开挖支护方法,汇总了施工中采用的技术参数,以期为本工程或类似工程引水隧洞掘进过程中不良地质洞段施工提供参考。

Various diabase vein alteration occurred in the headrace tunnel of Yingliangbao Hydropower Station.When excavating crosses altered rock layer,geological problems such as rapid deformation,collapse,and water inrush are prone to occur,and such occurrences greatly affect construction of the project.In response to these problems,a series of treatment measures are taken during construction to effectively control the impact of geological disasters such as collapse,which greatly ensures construction safety and the progress.This paper describes in detail the method of excavation and support for altered rock layer of the headrace tunnel,and summarizes the technical parameters used in construction with a view to providing references for construction of headrace tunnels in unfavorable geological condition.