摘要
开挖步序的选择是超大跨隧道建设的关键技术问题。文章以京张高铁八达岭长城站为工程背景,采用数值模拟方法,对比分析了采用"品"字形开挖工法、双侧壁导坑法和三台阶预留核心土法3种工法时围岩的受力和变形特征。研究结果表明:采用"品"字形工法时围岩变形平稳增长,安全风险相对分散;采用双侧壁导坑法开挖中岩墙时,因跨度突然增大,围岩变形迅速增大,存在变形突变阶段,安全风险集中在中岩墙开挖阶段;采用三台阶预留核心土法时围岩变形集中在第一台阶的开挖阶段,安全风险也相对集中在该开挖阶段。采用"品"字形开挖工法时初期支护喷射混凝土的压应力最小,采用双侧壁导坑法在中岩墙开挖时将引起隧道拱顶受力形式的突然转换,导致喷射混凝土应力突然增加。
The selection of excavation sequence is the key technical issue in the construction of extra-large span tunnel.In this paper,based on the engineering background of Badaling Great Wall Station of Beijing-Zhangjiakou High Speed Railway,the stress and deformation characteristics of rocks induced by three kinds of excavation methods,namely the excavation method in shape of Chinese character of"品",double side drift method and threestep reserved core soil method,were compared and analyzed by using numerical simulation method.The results show that the deformation of surrounding rock increases steadily and the safety risk is relatively dispersed when using the excavation method in shape of Chinese character of"品".When the middle rock wall is excavated by using double side drift method,the deformation of the surrounding rock increases rapidly due to the sudden increase of the span,resulting to an abrupt deformation stage,and the safety risk is concentrated in the excavation stage of the middle rock wall.The deformation of the surrounding rock is concentrated in the excavation of the first step when using the three-ftep reserved core soil method,and the safety risk is also relatively concentrated in the first step excavation stage.The compressive stress of the initial shotcrete is the smallest by using the excavation method in shape of Chinese character of"品".When the excavation of the middle rock wall is carried out,the stress of the arch roof of the tunnel will be changed suddenly as using double side drift method,which will lead to the sudden increase of the stress of the shotcrete.
作者
刘建友
吕刚
张民庆
岳岭
罗都颢
LIU Jianyou;LV Gang;ZHANG Minqing;YUE Ling;LUO Duhao(China Railway Engineering Consulting Group co.,LTD,Beijing 100055;Project Management Center of MOR,Beijing 100844;China Railway Firth Bureau Group Corporation,Changsha 410117)
出处
《现代隧道技术》
EI
CSCD
北大核心
2019年第S02期578-584,共7页
Modern Tunnelling Technology
基金
中国铁路总公司重大课题(2014G004-C)
关键词
京张高铁
八达岭长城站
超大跨隧道
开挖工法
Beijing-Zhangjiakou High Speed Railway
Badaling Great Wall Station
Super-large span tunnel
Excavation method
