基于苏埃通道工程盾构施工过程中下沉量分析

Analysis of Sunk Volume in Shield Construction Process Based on Su AI Channel Project

盾构开挖隧道主要分为隧道掘进和管片拼装2大工序。在管片拼装过程中盾构主机处于静止状态,在此过程中将会产生主机整体下沉和栽头的现象。为了尽量避免下沉和栽头现象的出现,需要对主机的下沉量和栽头量的范围进行预测,在盾构隧道掘进工序末事先调整好姿态,使盾构在静止过程中的下沉量和栽头量正好与姿态调整量相抵消,从而保证隧道轴线与设计轴线一致。通过对盾体周围受到水土压力以及地基对盾构的反力进行分析计算,并利用Matlab软件对4种不同地层进行建模分析,求得盾构主机在各地层的下沉量和栽头量的范围。通过计算,在苏埃跨海通道工程盾构掘进段项目中,主机在淤泥质土等松软地层中姿态变化最大,最大栽头量约为0.38 m,整体下沉约0.12 m;在密实中粗砂地层中姿态变化最小,最大栽头量约0.13 m,整体下沉约0.04 m。通过得出的栽头量和下沉量的范围,进而实现对盾构姿态的提前调整。

The shield tunnel excavation tunnel is mainly divided into two major processes: tunnel excavation and segment assembly. In the process of segment assembly, the host machine of the shield is at a standstill. In this process, the overall sinking and head felling of the host machine may appear. In order to avoid the phenomena, it is necessary to make a prediction on sinking size and head fellingsize of the host machine, and adjust the attitude in advance at the end of the tunneling process of the shield machine. In the static process of the shield machine, the sinking size and the head felling sizeare exactly offset by the amount of posture adjustment, so it can ensure the tunnel axis is consistent with the design axis. In this paper, the water and soil pressure around the shield and the reaction force of the foundation to the shield machine are analyzed and calculated. The Matlab software is used to model and analyze four different stratum, and the sinking and head fellingsize planting of the shield mainframe in each layer are obtained. Through calculation, in the shield tunneling section of the Soviet Union cross sea passage project,the host machine has the largest change in posture in soft soil such as silty soil, the maximum head felling amount is about 0. 38 m, and the overall sinking is about 0. 12 m;in the dense medium coarse sand stratum, the attitude change is the smallest, and the maximum heading amount is about 0. 13 m. The overall sinking is about 0. 04 m. The range of the amount of the head felling and the amount of sinking is obtained, thereby realizing the advance adjustment of the attitude of the shield machine.