TBM穿越超长距离断层破碎带施工技术研究

Study of construction technology for TBM to cross super-long fault fracture zone

针对广西桂中治旱乐滩水库引水灌区一期工程北干1标段16.07 km隧洞TBM掘进过程中突遇超长距离断层破碎带的恶劣地质条件,结合以往的TBM施工经验,通过对TBM设备改良和对TBM施工技术研究改进,采取了超前水平钻探取芯、Mcnally系统支护、侧墙防坍塌临时支护、隧洞仰拱软基换填、侧墙大撑靴加压、长距离隧洞皮带洞内冷粘、断层破碎带拱架更换等多种关键施工技术以及固结灌浆等其他施工技术相结合的方式,保证TBM设备安全、快速地通过了该段超长距离断层破碎带,提升了TBM在相似地层中的施工能力。

Tunnel boring machine(TBM)was utilized in the construction of a 16.07km-long tunnel,a component of the North trunk canal of Letan Reservoir Irrigation Zone 1st-stage Project.A super-long fault fracture zone with poor geological condition is unforeseen during construction.Based on the previous experience in the construction with TBM,TBM equipment was modified and TBM construction technology was studied for improvement.Multiple key construction technologies were adopted to ensure TBM crosses the fault fracture zone safely and rapidly includ⁃ing horizontal probe drilling,Mcnally support system,temporary side wall retaining support,changing and filling of soft ground of vault of bore hole,increasing of pressure at side wall gripper shoes,cooling of conveyor belt inside the long distance bore hole,replacement of steel arch in the fault fracture zone,consolidation grouting.The construction capability of TBM in similar strata is enhanced.