新型悬臂式结构托换桩基技术在地铁车站施工中的应用

Application of New Cantilever Structure Underpinning Pile FoundationTechnology in Construction of Metro Station

轨道交通工程施工过程中难免会出现城市既有桥梁侵入地铁车站的情况,对此,传统的方法是采用受力桩+托换梁方式对既有桥梁桩基进行托换,其往往存在因托换梁跨度过大而导致出现工期长、托换施工工序复杂、工程量大等缺点。针对大跨度托换梁施工的缺点,采用桩+承台的方式对桥桩进行托换,创新出悬臂式结构托换桩基施工技术,创造了一个在城市复杂交通环境条件下大规模、高强度、高标准、高难度桩基托换工程施工实例。阐述了该项施工技术创研与实施的过程。

During construction of rail transit projects,it is inevitable that existing urban bridges invade metro stations.In this regard,the traditional way is to underpin the pile foundations of existing bridges by means of stressed piles plus underpinning beams.Replacement of large span beams has shortcomings such as long construction period,complicated underpinning construction procedures,and huge engineering quantity.In view of the shortcomings of the large-span underpinning beam construction,the bridge piles are underpinned by the methods of pile plus cap,thus the construction technology of cantilever structure underpinning pile foundation is innovated,setting an engineering example of pile replacement with large-scale,high intensity,high standard and difficulty under complex traffic condition.This paper expounds the process of study,innovation and engineering practice of the technology.