高水敏性极软岩地下洞室底板超挖原因分析及应对措施  

Causes and countermeasures of over-excavation of underground cavern floor in extremely soft rockmass with high water sensitivity

作　　者：黄振伟 张涛 赵冰波 杜胜华 HUANG Zhenwei;ZHANG Tao;ZHAO Bingbo;DU Shenghua(Changjiang Geotechnical Engineering Co.,Ltd.,Wuhan 430010,China;National Research Center for Dam Safety Engineering,Wuhan 430010,China)

机构地区：[1]长江岩土工程有限公司,湖北武汉430010 [2]国家大坝安全工程技术研究中心,湖北武汉430010

出　　处：《水利水电快报》2022年第11期48-53,共6页Express Water Resources & Hydropower Information

基　　金：国家重点研发计划(2018YFC1505006);中国大唐集团公司科研项目(DTXZ-02-2021)。

摘　　要：为研究隧洞工程底板部位超挖的原因及应对措施,以西藏拉洛水利枢纽工程引水发电隧洞为例,基于地质条件、施工条件、底板超挖状态,得出底板超挖是内因、外因综合作用的结果:(1)岩石岩性软弱属内因,机械设备反复碾压和水属外因;(2)岩石软弱和机械设备反复碾压是必要因素,水是起加剧作用的非必要因素。在结合其他隧洞施工经验的前提下,提出了减少或避免底板超挖的各种工程处理措施。此外,对隧洞底板超挖引起的设计变更或索赔进行了探讨。研究成果可为类似工程提供参考。In order to research the causes and countermeasures of tunnel floor over-excavation, based on the geological conditions, construction conditions and floor over-excavation states of the diversion tunnel of Laluo Hydro Project in Tibet, it is proposed that the tunnel floor over-excavation is due to the interaction between internal and external factors:(1) The weak rock lithology is the internal factor, while the repeated mechanical rolling and water are the external factors.(2) The weak rockmass and the repeated mechanical rolling are the necessary factors, and water is the unnecessary factor that aggravates the over-excavation.On the premise of former engineering experiences in other tunnel construction projects, various engineering treatment measures were proposed to reduce or avoid floor over-excavation.Besides, the management for design change and claim caused by the over-excavation of the tunnel floor were also discussed.The research results can be a reference of reliable, economic and effective treatment schemes for similar projects.

关 键 词：极软岩 水工隧洞 底板超挖 应对措施 拉洛水利枢纽工程 西藏 

分 类 号：TV554[水利工程—水利水电工程]