京张高铁清华园隧道复合地层盾构机械配置研究

Selection of Shield Machines for Complex Strata of Tsinghuayuan Tunnel in Beijing-Zhangjiakou High-speed Railway

依据清华园隧道盾构区间的隧道参数和工程地质条件,分析盾构机刀盘和刀具对卵石土、砂、粉质黏土互层的适应性。从地层渗透系数、颗粒级配、地下水压、周边环境影响、隧道规模等方面进行综合考虑,选取泥水平衡盾构作为最终选型。考虑到刀盘跨度较大和中途换刀对盾构稳定性的影响,结合渣土特性和既有工程经验,决定采用辐条面板式刀盘,并确定了开口率和开口尺寸;此外,还给出了以切削型为主且可常压更换的刀具配置方案。最后简要介绍了常压换刀的技术流程和泥水环流系统的设计方案,总结了卵石土、砂、粉质黏土互层的盾构机械配置方案。

According to the tunnel parameters and engineering geological conditions of the shield section of the Tsinghuayuan Tunnel in the JZSG-1 section of the Beijing-Zhangjiakou High-speed Railway,combined with the difficulty and the design requirements of the shield machine,the shield cutter heads and cutters are analyzed for the adaptability to the interbedded strata of pebble soil,sand and silty clay.Considering from multiple aspects such as permeability coefficient of strata,grain grading,groundwater pressure,surrounding environment and tunnel size,the slurry shield is selected as the final selection.The spoke plate cutter head is chosen,and the cutting tools configuration scheme which is dominated by cutting-type cutters and could be changed under normal pressure is put forward,matching the actual construction.Finally,the tool changing technical process under normal pressure and design scheme of slurry circulation system are introduced.The selection scheme of shield machine for interbedded strata of pebble soil,sand and silty clay is summarized.