下穿陇海铁路大断面斜交箱桥顶进施工测量技术

Construction Survey Technology for Jacking of Skew Box Bridge with Large Cross Section Under Longhai Railway

随着城市规模不断扩大,下穿既有铁路顶进桥涵工程越来越受到建设方青睐。在不影响铁路既有线正常运营情况下,如何将城市道路大断面斜交箱型桥快速下穿既有线成为诸多工程面临的难题。在既有铁路左右两侧将预制成型的箱型立交桥顶至设计位置保证中线及标高顺利对接并防止中线偏位及涵身抬头、扎头情况出现对测量控制工作提出了更高要求。本文对经九路下穿陇海铁路大断面斜交框构立交桥顶进过程测量控制技术进行阐述,并提出箱型桥在顶进过程中容易出现中线偏位和抬头、扎头的原因及处理措施,以期对同类工程提供借鉴。

With the continuous expansion of the city scale,the project of jacking bridges and culverts under the existing railway is more and more favored by the construction side.Without affecting the normal operation of existing railway lines,it is a difficult problem for many projects to pass the large-section skew box-shaped bridges of urban roads quickly through the existing railway lines.On the left and right sides of the existing railway,the precast box-shaped overpass is connected from the top of the bridge to the design position to ensure the smooth connection of the center line and elevation,and to prevent the center line from being deviated and the body from raising and sticking,which puts forward higher requirements for the measurement and control work.In this paper,the measurement and control technology for jacking process of large cross-section skew frame overpass with nine-way crossing under the Longhai Railway is described,and the causes and treatment measures for the midline deviation,head-up and lowering-head of box-shaped bridge in jacking process are put forward,in order to provide reference for similar projects.