北京地铁8号线安—安区间明挖盾构始发井快速提供始发条件技术探讨

Optimization of Construction Program of Shield Launching Shaft to Achieve Earlier Shield Launching:Case Study on Shield Launching Shaft of Anhuaqiao Station-Andelibeijie Station Section of Line 8 of Beijing Metro

随着城市轨道交通的迅猛发展,盾构区间隧道被大量采用,如何快速利用盾构井提供盾构始发条件,成为设计及施工人员需要考虑的问题。以北京地铁8号线安华桥站—安德里北街站区间(简称安—安区间)盾构井为研究对象,取消该盾构井地下1层和地下2层结构,并通过理论计算,采用混凝土腰梁代替钢支撑的作用。结果显示,安—安区间盾构井在回筑、盾构机始发吊装及盾构机掘进期间,该盾构井周边地表沉降最大值仅6.42 mm,周边管线沉降不足1 mm。从而证明:在单个盾构井中,采用混凝土腰梁代替钢支撑可以满足安全、快速提供盾构始发条件的要求。

With the development of urban rail transit works, more and more shield tunnels are built. Due to the tight construction schedule of the shield tunnels, how earlier shield launching can be achieved in the shield launching becomes the focus of the designer and the contractor. The originallydesigned concrete structure of the first and second underground floors of the shield launching shaft of Anhuaqiao StationAndelibeijie Station Section of Line 8 of Beijing Metro is cancelled and reinforced concrete waling is used to replace the originallydesigned steel bracing, and earlier shield launching is achieved. During the construction of the project, the ground surface settlement is monitored. The monitoring results show that the maximum settlement of the ground surface surrounding the shield launching shaft is 6.42 mm, and the settlement of the utility lines is less than 1 mm. The practice shows that reinforced concrete waling can be used to replace the originallydesigned steel bracing, so as to achieve earlier shield launching.