双孔大跨径框架桥顶进下穿既有铁路线施工技术研究

Research on Construction Technology of Double Span Frame Bridge Crossing Existing Railway Line by Jacking

本文主要介绍了在武深高速公路始兴联络线项目下穿既有铁路框架桥顶进施工中,由于该框架桥为双孔大跨径设计,所顶进下穿的赣韶铁路路基距离框架桥顶覆土约1.9m,施工难度大,安全风险高。为确保该框架桥能够顺利顶进,使其标高与位置满足要求,同时还要确保既有铁路线运营安全。为此项目部对该框架桥施工方案进行仔细研究,对施工工序进行优化,同时对施工安全措施进行严格把控,通过上述一系列举措,不但保证了该框架桥顶进施工中既有铁路线的安全运营,而且也使得框架桥顶进后其顶板和底板标高位置符合相关要求。该双孔大跨径框架桥下穿既有铁路线顶进施工所涉及的工艺和措施也为后续类似施工提供了借鉴和参考。

This paper mainly introduces the jacking construction of the existing railway frame bridge under the Shixing connecting line project of Wuhan Shenzhen Expressway.Because the frame bridge is designed with double holes and large spans,the subgrade of Ganshao Railway which is jacked into the underpass is about 1.9m away from the top soil of the frame bridge,which is difficult to construct and has high safety risks.In order to ensure the smooth jacking of the frame bridge,make its elevation and position meet the requirements,and ensure the safety of the existing railway line.For this reason,the Project Department carefully studied the construction scheme of the frame bridge,optimized the construction process,and strictly controlled the construction safety measures.Through the above series of measures,not only the safe operation of the existing railway lines during the jacking construction of the frame bridge was ensured,but also the elevation positions of the top and bottom plates of the frame bridge after jacking met the relevant requirements.The technology and measures involved in the jacking construction of the double span long-span frame bridge under the existing railway line also provide reference for the subsequent similar construction.