深埋穿越向斜构造引水隧洞变形致灾机理研究  

Deformation Disaster Mechanism of Deep Buried Diversion Tunnel Through Syncline Structure

作　　者：刘俊峰 LIU Junfeng(The Second Engineering Co.,Ltd.of China Railway 18th Bureau Group Co.,Ltd.,Tangshan,Hebei 064000,China)

机构地区：[1]中铁十八局集团第二工程有限公司,河北唐山064000

出　　处：《施工技术(中英文)》2025年第6期15-23,共9页Construction Technology

基　　金：中铁十八局集团第二工程有限公司、西南交通大学联合科研课题(2⁃JF⁃2021⁃滇中引水⁃2⁃001)。

摘　　要：为探究穿越高地应力地区引水隧洞大变形致灾机理,明确隧洞变形基本形式,采用现场调查、地应力场预测分析等方法,对狮子山隧洞穿越乌龙坝向斜次级构造发生的大变形灾害机理进行了分析。研究结果表明:研究区域存在节理裂隙发育的凝灰岩软弱破碎带、高外水压及向斜储水构造等地质条件,构成复杂的原岩应力场。开挖卸荷效应是隧洞穿向斜构造极高~高应力软岩变形致灾的根源,隧洞开挖破坏了原始地应力平衡状态,而支护体系不能对围岩进行有效支护,导致围岩结构整体失稳。在极高~高地应力原岩应力环境条件下,凝灰岩软弱破碎带及地应力方位与隧洞轴线夹角是导致变形破坏的非对称性的主要因素,水与破碎围岩的固-流耦合作用是软岩劣化、应力场改变、渗透压力增大等的决定性因素。In order to explore the disaster⁃causing mechanism of large deformation of diversion tunnel passing through high ground stress area and clarify the basic form of tunnel deformation,the large deformation disaster mechanism of Shizishan Tunnel passing through the secondary structure of Wulongba syncline is analyzed by means of field investigation and prediction analysis of ground stress field.The results show that:There are geological conditions such as weak fracture zone of tuff with joint fissure development,high external water pressure and syncline water storage structure in the study area,which constitute a complex original rock stress field.Excavation unloading effect is the root cause of the deformation of the soft rock with extremely high⁃high stress in the tunnel through syncline structure.Tunnel excavation destroys the original equilibrium state of ground stress,and the support system can not effectively support the surrounding rock,resulting in the overall instability of the surrounding rock structure.Under the condition of extremely high⁃high ground stress in⁃situ rock stress environment,the weak fracture zone of tuff and the angle between ground stress orientation and tunnel axis are the main factors leading to the asymmetry of deformation and failure.The solid⁃fluid coupling effect of water and broken surrounding rock is the decisive factor of soft rock deterioration,stress field change and seepage pressure increase.

关 键 词：引水隧洞 向斜构造 深部岩体 高地应力 围岩 变形 致灾机理 

分 类 号：U456[建筑科学—桥梁与隧道工程]