全风化花岗岩富水隧道浅埋段开挖施工技术研究

Study on excavation construction technology for shallow buried section of fully weathered granite water tunnel

石长铁路与益娄铁路间下行疏解线李家冲隧道为单线隧道,穿越地层为燕山晚期花岗岩全风化层,结构较松散,透水性强,自稳性差,在重力作用下易坍塌。该隧道多处浅埋,局部存在软弱夹层及导水裂隙,地质条件差,地下水发育,为确保安全顺利的通过浅埋段施工,结合施工实践介绍全风化花岗岩浅埋富水隧道开挖施工技术,以供参考。

The downstream dredging line of Lijiachong tunnel was a single-line tunnel,which between the Shimen-Changsha Railway and the Yiyang-Loudi Railway.The crossing stratum was a fully weathered layer of Late Yanshanian granite with loose structure,strong water permeability,and poor self-stabilization.It easily collapses under the action of gravity.The tunnel has many shallow burial sites,with weak interlayers and water-guiding fissures locally,poor geological conditions,and groundwater development.To ensure safe and smooth construction through shallowburied sections,this paper describes the construction of shallow-buried water-enriched tunnels for full-weathering granites in combination with construction practices.Technology for reference.