摘要
为解决特大断面黄土隧道采用双侧壁导坑法施工进度慢、成本高的问题,以G30连霍高速公路清水驿至忠和段扩容改造工程凤凰山隧道为背景,提出五步单侧壁导坑法。通过数值模拟对比分析双侧壁导坑法、五步单侧壁导坑法、传统单侧壁导坑法和台阶法在施工过程中的围岩变形及钢拱架应力,并结合现场试验段监测数据验证特大断面凤凰山隧道采用五步单侧壁导坑法施工的可行性。结果表明:1)五步单侧壁导坑法拱顶沉降和水平收敛比传统单侧壁导坑法分别减小3.59 cm和1.31 cm,比双侧壁导坑法分别增大1.4 cm和0.59 cm;钢拱架应力除拱肩外均小于双侧壁导坑法,最大处减少了70 MPa,钢拱架应力最大值与钢材屈服强度的比值比双侧壁导坑法增大0.04,比单侧壁导坑法减小0.08。2)传统单侧壁导坑法的安全性小于五步单侧壁导坑法,改进后的五步单侧壁导坑法相比双侧壁导坑法能在控制围岩变形的同时加快施工进度,降低施工成本。3)五步单侧壁导坑法中隔壁的最优位置应结合具体工程情况进行单独优化计算,针对本工程而言,其最优位置为45%洞宽。
The double side-drift method used in super-large cross-section loess tunnels is slow in tunneling advance and costly.To address these challenges,a case study is conducted on the expansion and reconstruction project of the Fenghuangshan tunnel from Qingshuiyi to Zhonghe section of the G30 Lianyungang-Khorgos expressway,and a five-step single side-drift method is proposed.The surrounding rock′s deformation and streel arch′s stress when employing the double side-drift,five-step single side-drift,conventional single side-drift,and bench methods are comparatively analyzed.Finally,the feasibility of the five-step single side-drift method for constructing the Fenghuangshan tunnel is validated through field monitoring data.The results reveal the following:(1)The crown settlement and horizontal convergence of the five-step single side-drift method are 3.59 cm and 1.31 cm lower than those of the conventional single side-drift method and 1.4 cm and 0.59 cm higher than those of the double side-drift method.The stress of the steel arch is less than that of the double side-drift method except for the arch shoulder,with a maximum reduction of 70 MPa.The ratio of the maximum stress of the steel arch to the steel yield strength is 0.04 higher than that of the double side-drift method and 0.08 lower than that of the single side-drift method.(2)The traditional single side-drift method is less safe than the five-step single side-drift method.The improved five-step single side-drift heading method,compared with the double side-drift method,can accelerate construction progress and reduce construction costs while controlling surrounding rock deformation.(3)The optimal position of the partition wall in the five-step single side-drift method is 0.45 times the hole width in the Fenghuangshan tunnel and should be adjusted based on actual conditions for further application.
作者
乔明磊
李盛
张建功
王起才
薛彦瑾
陈智刚
QIAO Minglei;LI Sheng;ZHANG Jiangong;WANG Qicai;XUE Yanjin;CHEN Zhigang(College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,Gansu,China;China Seventeen Metallurgical Group Co.,Ltd.,Ma′anshan 243000,Anhui,China;Lanzhou Jiaotong University Road and Bridge Engineering Disaster Prevention Technology National Local Joint Engineering Laboratory,Lanzhou 730070,Gansu,China)
出处
《隧道建设（中英文）》
CSCD
北大核心
2024年第5期1096-1105,共10页
Tunnel Construction
基金
甘肃省基础研究创新群体项目(21JR7RA347)
甘肃省自然科学基金项目(22JR5RA338)
宁夏重点研发计划资助(2022BEG02056)。
关键词
特大断面黄土隧道
五步单侧壁导坑法
数值模拟
现场试验
super-large cross-section loess tunnel
five-step single side-drift method
numerical simulation
field monitoring
作者简介
第一作者:乔明磊(1999-),男,河南许昌人,兰州交通大学土木工程专业在读硕士,研究方向为隧道工程。E-mail:1203761063@qq.com;通信作者:李盛,E-mail:ligwin@126.com。
