大直径盾构隧道中隔墙施工流程及精度控制

Construction Process and Precision Control of Middle Partition Wall in Large Diameter Shield Tunnel

以上海机场联络线3标为工程背景,对大直径盾构隧道中隔墙的作业过程及误差控制进行研究。首先,根据设计方案和施工情况,对中隔墙的整体施工流程进行梳理。其次,确定了中隔墙的安装方法,同时针对中隔墙安装精度提出相应的控制措施,既提高了中隔墙的施工效率,又具有安全稳定、成本低且易推广等特点。最后,选取部分中线拼装偏差测量数据,对中隔墙安装时的精度控制效果进行A类不确定度分析。结果表明:中隔墙的旋转中心距离中隔墙底部为4034 mm,中隔墙的抬升高度为1838 mm。对第995、1000、1005环的中线偏差数据采用A类不确定度予以评判,测量结果分别为1.05、2.05、3.06 mm,检测的次数各为20次,自由度为19,置信概率95%,测量精度很高。

This paper examined the operational process and error analysis of the middle partition wall of large diameter shield tunnel,with a particular focus on the third bid project of Shanghai Suburban Railway Airport Link Line.Firstly,the overall construction process of the middle partition wall was outlined according to the preliminary design scheme and the construction site situation.Secondly,the installation method of the middle partition wall was determined,and the corresponding control measures were put forward for the installation accuracy of the middle partition wall.This not only improves the construction efficiency of the middle partition wall,but also has the characteristics of safety and stability,low cost and easy promotion.Finally,some of the midline deviation measurement data were selected for analysis of the type A uncertainty of the accuracy control effect when the middle partition wall was installed.The results show that,the rotation centre of the middle partition wall is 4034 mm from the bottom of the middle partition wall,and the lifting height of the middle partition wall is 1838 mm.The midline deviation data of the 995th,1000th and 1005th rings are evaluated by class A uncertainty.The measurement results are 1.05,2.05 and 3.06 mm,respectively.The number of detections is 20 times,the degree of freedom is 19,and the confidence probability is 95%,which proves a high measurement accuracy.