高速上跨铁路立交主桥施工技术研究

Study on Construction Technology of Main Bridge of High Speed Overpass Railway

【目的】本研究对延安东绕城高速公路上跨包西铁路、西延高铁立交工程主桥施工技术开展系列探讨。主桥桥型为2×70 m预应力混凝土变截面箱型T型钢构桥,整幅设置,整幅宽33.6 m。【方法】主桥T构梁采用转体法浇筑。该桥主梁为单箱四室双斜腹梁的单元截面;主墩为空心桥墩,单箱双室散射截面大;该桥采用单墩式转体制,转体系统包含下转盘、中铰、上转盘、转体牵引装置等构造。对主梁、主墩、转体结构采用Midas Civil程序和Midas FEA进行计算。【结果】计算结果显示其所有技术指标都符合标准要求。【结论】该桥的施工方案结构设计合理、经济性好,尽可能地保证了其施工期间铁路轨道的安全运营。

[Purposes] The study aims to carry out a series of discussions on the construction technology of the main bridge of Yan′an East Ring Expressway crossing Baoxi Railway and Xiyan High-speed Railway.The main bridge is a 2 × 70 m prestressed concrete variable cross-section box T-shaped steel structure bridge,with the whole width of 33.6 m.[Methods] The T-beam of the main bridge was poured by the rotation method.The main girder of the bridge is the unit section of the single-box four-cell doubleoblique web beam;the main pier is a hollow pier,and the single-box double-chamber scattering cross section is large;the bridge adopts a single-pier rotation system,and the rotation system includes a lower turntable,a middle hinge,an upper turntable,and a rotation traction device.The main girder,main pier and swivel structure are calculated by Midas Civil program and Midas FEA.[Findings] The calculation results showed that all the technical indexes met the standard requirements.[Conclusions] The structural design of the construction scheme of the bridge is reasonable and economical,and the safe operation of the railway track during the construction period is ensured as much as possible.