摘要
针对超大断面隧道变截面软弱围岩段存在的工程技术难题,结合新考塘铁路隧道出口段工程地质条件,对超大断面隧道变截面软弱围岩段施工方法进行了研究。从大墙脚复合双侧壁双层支护、水平旋喷桩与大管棚联合超前支护两方面对软弱围岩超大断面开挖支护关键技术进行了研究分析,并对过渡段位置开挖及靴型大墙脚基础施工技术要点及注意事项进行了详细阐述。研究结果表明:超大断面软岩隧道采用型钢拱架和格栅钢架双层初期支护技术,提高了初支结构的承载能力;采用靴型大墙脚并结合钢花管底部注浆技术,提高了边墙脚的稳定性,减少了边墙的变形和拱部的沉降。
Aiming at solving the engineering and technical problems encountered in the projects of extra large-section and varia-ble-section tunnels in the weak surrounding rock section and with the engineering geological conditions of the outlet section of the Xinkaotang Railway Tunnel taken into account, the construction methods for extra large-section and variable-section tunnels in the weak surrounding rock section are studied in the paper. The key techniques such as the composite large-wall-foot-dual- side-wall-double-decker support method and the horizontal rotating-jet grout pile-and-big-tube-shed advanced support method for extra large-section excavation in the weak surrounding rock are studied and analyzed, with the significant technical points and important points for attention in the excavation of the transitional sections and the basic construction of the large boot-type wall foot dealt with in detail. The result of our studies shows that with the double-decker initial support technique of steel arch frame and grill steel frame adopted for extra large-section weak-rock tunnels, the bearing capability of the initial support is im-proved; with the large boot-type wall foot combined with the holed steel tube bottom grouting technique adopted for extra large- section weak-rock tunnels, the stability of the foot of the side wall is improved,with the deformation of the side wall and the settlement of the arch reduced.
作者
崔乐健
CUI Lejian(The Tunnel Co. Ltd. of China Railway,Zhengzhou 450003, Chin)
出处
《国防交通工程与技术》
2018年第3期58-62,共5页
Traffic Engineering and Technology for National Defence
关键词
大断面隧道
软弱围岩
变截面
支护
large-section tunnel
weak surrounding rock
variable section
support
