武汉地铁出入口顶管施工风险控制分析

本文以武汉市轨道交通3号线一期工程宗关站Ⅲ、Ⅳ号出入口的实际施工情况为背景，针对施工过程中可能出现的各种不同的风险，并同时结合实际的监测数据，进行了综合分析。考虑到顶管施工技术在武汉市这种软土地区还未广泛运用，且施工人员的顶管施工经验不足，对这一施工技术中存在的风险问题进行及时预防，并采取相应的措施予以控制，显得尤为必要，同时也为今后的类似工程提供宝贵的经验材料。通过对宗关站Ⅳ号出入口的顶管施工过程和实际监测数据进行分析，可以得出如下结论：(1)在施工现场不同部位布设监测点能有效地避免风险的发生；(2)Ⅳ号出入口顶管施工过程中，地表沉降量远远大于周边建筑物的沉降量，且最大沉降可达58.58mm，且随着顶管的顶进，呈现逐渐增大趋势；(3)顶管通道周边的高架桥墩的沉降量很小，且不超过2mm，沉降值大体保持稳定。

Risk Control Analysis of Metro Entrance/Exit Tunnel Constructed by Pipe Jacking Method in Wuhan

According to practical construction case of No.3 and No. 4 entrance / exit tunnel of Zongguan station in the 1st phase of Wuhan Metro Line 3, this paper gives a comprehensive analysis of all kinds of possible emerging risks in the construction process combining the practical monitoring data. Considering that the pipe jacking construction technology has not been widely used in soft soil area like Wuhan, and the constructors lack experience of pipe jacking construction, it would be necessary to the all construction process if related personnel take some actions to prevent and control the existing risk problems in the construction technology. Meanwhile, it could also offer the valuable experiences to similar projects in the future. Through analyzing the process of pipe jacking and practical monitoring data in No. 4 entrance / exit tunnel of Zongguan station, we could draw the following conclusions : (1) Laying the monitoring points in different places of the construction site could effectively avoid the occurrence of risk; (2) During the construction process of No. 4 entrance / exit tunnel, the ground settlement is much larger than the surrounding buildings settlement, the maximum could reach 58.58 mm, and it would gradually increase with the advance of pipe jacking. (3) The settlement of the bridge pier around the tunnel constructed by Rectangular Pipe Jacking Method is very small. The settlement of the bridge pier is far less than 2mm, and the settlement value keeps stable in general.