地铁施工明挖段向暗挖段转换破桩出洞的抬桩法施工技术

在地铁施工中，由明挖段（如地铁车站）向暗埋段掘进时，需破除明挖段的支护桩方能出洞。如处理不当，易发生“掉桩”和土体突涌等事故。为避免险情，应采用冻结的方法。本文根据某南京地铁工程实例，介绍了一种“抬桩法”出洞方法，以供读者参考。

Construction Technology of Lifting Pile Method in the Conversion from the Open-cut Section to Undercutting Section to Tunneling Out in the Subway Construction

In metro construction, when the operation carries on from the open excavation section （subway station） to the buried section, builders need to get rid of the supporting pile in open cut section to construct the subway out of the tunnel. If handled improperly, it prone to pile dropping or quick soil etc.. In order to avoid danger, builders should adopt the freezing method. According to a subway project in Nanjing city, the author introduces a method of “lifting the pile of the tunnel？, providing a reference to the reader.