不同大变形等级层状软岩隧道施工关键技术研究  

Research on key construction technology of layered soft rock tunnel under different large deformation grades

作　　者：潘文韬 吴枋胤 杨文波[1] 寇昊 徐迪 孟海龙 何川[1] 王飞 PAN Wentao;WU Fangyin;YANG Wenbo;KOU Hao;XU Di;MENG Hailong;HE Chuan;WANG Fei(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu 610031,Sichuan,China;Sichuan Mianjiu Expressway Co.,Ltd.,Chengdu 610041,Sichuan,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [2]四川绵九高速公路有限责任公司,四川成都610041

出　　处：《建筑科学与工程学报》2023年第5期148-161,共14页Journal of Architecture and Civil Engineering

基　　金：四川省交通运输科技项目(2019ZL09)。

摘　　要：为探究不同大变形等级层状软岩隧道施工方案,依托九绵高速全线大变形隧道,根据现场施工及效果初步设立对比工况;通过试验确定围岩参数,采用数值模拟对不同工况围岩支护受力变形进行比选验证,确定不同大变形等级工法、超前加固、支护方案,并通过现场施工及结构受力情况进行验证。结果表明:现场大变形等级与变形量表现出聚集性;轻微大变形在拱顶、拱腰处变形接近,中等、强烈大变形集中于拱顶或拱腰;轻微大变形宜采用二台阶法,采用加强单层小导管以及长短锚杆结合的方式意义不大;中等大变形宜采用三台阶法,并采用单层小导管(∅51,长6 m)以及长短锚杆结合的方式;强烈大变形宜采用三台阶留核心土法,扩大拱顶注浆范围并采用双层初期支护,视工程重要性选用双层小导管以及中管棚的超前加固方式。In order to explore the construction scheme of layered soft rock tunnel under different large deformation grades,relying on large deformation tunnels of Jiumian expressway,the comparative working conditions were preliminarily established according to the on-site construction and effect.Surrounding rock parameters were determined by experiments and the stress and deformation of surrounding rock and supporting structures under different working conditions were compared and verified by numerical simulation.Construction method,advance reinforcement and lining support schemes were determined under different large deformation grades and verified by on-site construction and structural stress.The results show that on-site large deformation grade and amount show aggregation.The deformation of vault and spandrel are close under slight large deformation,and the medium and strong large deformation is concentrated on the vault or the arch waist.Under slight large deformation,the two steps method should be adopted.It is of little significance to strengthen single-layer small conduit and adopt the combination of long and short bolts.The three steps method should be adopted for medium large deformation,and single-layer small conduit(∅51,6 m long)and the combination of long and short bolts should be adopted.Under strong large deformation,it should use three steps to retain core soil method,expanding the vault grouting range,and adopting double-layer initial support.According to the project importance,the advance reinforcement method of double-layer small conduit and middle pipe shed is selected.

关 键 词：隧道工程 施工技术 数值模拟 层状软岩 大变形等级 现场监测 

分 类 号：U456.3[建筑科学—桥梁与隧道工程]