北京地铁隧道水平冻结法施工

北京复八线地铁“大-热”区间南隧道施工时，拱顶遇到饱和含水的粉细砂层，此段隧道地处国贸立交桥下，又有多条地下管线，为了确保地下管线和地面交通的正常使用和安全运行，在国内首次实施了隧道内的水平冻结加固施工。本文论述了该工法的设计、关键技术的处理以及实际取得的效果，探讨了人工地层冻结和浅埋暗挖技术相结合的发展方向。

Horizontal ground freezing method applied to tunneling of Beijing Underground Railway System

During the construction of the south railway tunnel in DaRe Area of Beijing Underground Railway System, there was a water saturated layer of fine sand on the roof of the tunnel area. The tunnel area is located under the Guomao Overpass and there are several underground pipelines located in the tunnel area. To assure a normal operation and safety of the pipelines and overpass , horizontal ground freezing method was applied to the tunneling for the first time in China. This paper has stated the design, the key technologies and the practical results of this method, and discussed the technical tendency in combination of the ground freezing and the excavation with a shallow depth.