盾构掘进姿态控制技术研究

盾构机在城市地铁施工中已经成为主流,盾构在掘进中的姿态控制是确保隧道施工质量的关键技术.由于影响盾构掘进姿态的因素较多,情况复杂,掘进姿态控制难度大.本文结合南京地铁三号线某标段隧道盾构施工,分析隧道设计轴线、盾构轴线和管片中线三者在施工中存在的5种位置关系：一是三条线基本重合,二是盾构轴线与隧道轴线重合,三是管片中线与隧道设计轴线重合,四是管片中心与盾构轴线有偏差,五是三条轴线不重合而且轴线水平移动;从土压的设定值、地质变化、注浆位置与时间、转弯管片的使用、管片的姿态和施工的连续性等6个方面对影响盾构掘进姿态的因素进行总结;从偏移量、油缸行程差和最小盾尾间隙三个方面对盾构掘进姿态控制的参数进行分析与计算;从掘进方向的控制,掘进姿态调整与纠偏两个方面阐述盾构掘进过程中姿态控制的技术方法.

The Study of Shield Tunneling Attitude Control Technology

Shield machine has become the mainstream in the urban subway construction, and the shield tunneling attitude control is the key technology to ensure the quality of the tunnel construction. Due to the factors of effecting shield tunneling attitude control, it is very difficult to control the shield tunneling attitude. Based on a bid of Nanjing metro line 3 in shield tunneling construction in this paper, five kinds of position among the tunnel design axis, the shield axis, and the segment midline are analyzed, including （1） the three lines coincide, （2） the tunnel design axis and the shield axis coincide, （3） the segment midline and the tunnel design axis coincide, （4） the deviation between the segment midline and the shield axis, and （5） noncoincidence among the three lines and the axis moves along the horizontal direction. The affecting factors from six aspects including the set value of earth pressure, variation of geology, the location and time of grouting, the use of curve segment, the attitude of segment, and the continuity of construction are summarized. Three parameters about shield tunneling attitude control including the length of the offset, the different trip and the space behind the shield machine are calculated. Finally, the methods of shield tunneling attitude control, including the direction of control, attitude adjustment in the aspect of rectifying are put forward.