山区大跨度悬索桥钢桁梁施工技术

为解决山区大跨度悬索桥钢桁梁架设施工受地形条件限制的问题,以坝陵河大桥为背景,研究桥面吊机悬臂架设法施工中不同区域的钢桁梁安装、钢桁梁合龙及钢桁梁提升等施工技术.首、次节梁段采用整体吊装施工,标准梁段及临时铰处梁段采用桁片吊装架设,并在临时铰处设置支撑系统(与钢桁梁铰接)；临时铰采用自然合龙,跨中钢桁梁合龙前调整竖向高差及上、下弦合龙口纵向相对偏差(暂不安装合龙口前端永久吊索),合龙时在桥塔处牵引钢桁梁调整纵向偏差；单点提升力大于2400 kN的梁段采用两点提升,其余梁段均采用单点提升.

Construction Techniques for Steel Truss Girder of Long Span Suspension Bridge in Mountainous Region

To cope with the problem that the erection of the steel truss girder of long span suspension bridge in mountainous region is restricted by the topographic conditions in the region,the Baling River Bridge is taken as an example,the construction techniques for the erection,closure and lifting of different areas of the truss girder,using the deck crane cantilever erection method are studied.According to the study,the first and secondary blocks of the girder should be integrally lifted and assembled,the typical blocks and the block at the temporary hinge should be lifted and assembled in each truss unit and the support system(hingedly connected with the girder) should be accordingly arranged at the temporary hinge.The temporary hinge should be closed in a natural way and before the closure of the midspan steel truss girder,the vertical height differences and the longitudinal relative deviation differences at the gaps of the upper and lower chords of the girder(the front end permanent suspenders are temporarily not assembled) should be adjusted.At the time of the closure,the girder is to be hauled at the tower to adjust the longitudinal deviation differences.For the blocks with the single-point lifting force greater than 2 400 kN,the two-point lifting should be applied while for the rest of the blocks,the single-point lifting should be used.