高速铁路大跨度空腹式连续刚构设计

银西高铁漠谷河2号特大桥桥高114 m,为适应桥高并结合地形起伏要求,主桥采用(120+210+120)m预应力混凝土空腹式连续刚构桥,主梁为拱形V撑与箱梁截面的新型组合结构形式,该结构为铁路预应力混凝土桥梁跨度之最。采用Midas软件对主桥进行结构计算,模拟悬臂浇筑法施工,辅助以临时扣锁和支架,使V撑上下弦可以同时施工。计算结果表明,该结构增加了结构的跨越能力,减少了跨中收缩徐变上拱值,在施工及运营阶段的刚度、强度均满足规范要求,具有良好的动力特性。该结构采用柱板式空心墩与主梁固结,线性优美,工程经济,结果可为铁路大跨高墩桥梁设计和施工提供参考。

The Design of High-speed Rail Large Span Open-spandrel Continuous Rigid Frame

The 2nd Mogu River Bridge on Yinchuan-Xi'an High Speed Railway is 114 m high. In order to meet the requirements of the bridge height and the terrain,the main bridge uses a( 120 + 210 + 120) m prestressed concrete continuous rigid frame. The main beam is in arched V form and a combined box girder structure,and the structure has the longest span ever built in railway prestressed concrete bridges.The Midas software is used to calculate the structure,simulate cantilever construction with temporary locking and stents,so that the upper and lower strings can be simultaneously constructed. The calculation results show that the structure increases the spanning capacity,reduces the arch value of creep,meets the specification requirements and achieves good dynamic performances. The hollow pier and main beam consolidation result in good linear form and low project,which can provide a reference for the design and construction of large span and high pier bridges.