重庆鹅公岩轨道专用桥加劲梁合龙关键技术

重庆鹅公岩轨道专用桥桥跨布置为(50+210+600+210+50)m,是目前世界上跨度最大的自锚式悬索桥.该桥加劲梁为5跨连续梁,锚跨和锚固段为混凝土梁,其余为钢箱梁.加劲梁锚固段采用可滑移现浇支架施工,锚跨采用常规现浇支架施工,边跨采用顶推法施工,中跨采用斜拉扣挂法施工.加劲梁先合龙边跨,后合龙中跨,最后合龙锚跨.通过在塔梁交叉处设置纵向位置调整系统、在混凝土锚跨下设置可纵向滑移支架主动控制合龙时机,避免了天气条件的不利影响,缩短了工期;通过有效控制锚固段及锚跨混凝土梁段的变形,减少施工对混凝土的扰动,从而控制混凝土梁段的质量;通过优化支架结构降低支架复杂程度和安全风险,从而降低支架费用.该桥加劲梁的合龙技术,可为同类桥梁施工提供借鉴.

Key Technology of Closure of Stiffening Girders for Egonyan Urban Rail Transit?dedicated Bridge

The bridge span arrangement of the Egongyan urban rail transit-dedicated bridge is(50+210+600+210+50)m,which is the largest self-anchored suspension bridge in the world.The stiffening girder of the bridge is a five-span continuous girder,the anchorage span and anchorage section are concrete girders,and the rest are steel box girders.The anchorage section of the stiffening girder is constructed with cast-in-place sliding bracket,the anchor span is constructed with cast-in-place conventional bracket,the side span is constructed with push up method,and the middle span is constructed with the method of cable-stayed buckle.The stiffening girder closes the side span first,then the middle span,and finally the anchor span.By setting up longitudinal position adjustment system at the intersection of tower and girder and setting longitudinal sliding bracket under concrete anchor span,the closure time can be controlled actively,which can avoid the adverse effects of weather conditions and shorten the construction period.By effectively controlling the deformation of the anchorage section and the anchorage span concrete girder section,the disturbance of the construction to the concrete is reduced,so as to control the quality of the concrete girder section.By optimizing the bracket structure,the complexity and safety risk of the bracket are reduced,so as to reduce the cost of the bracket.The closure technology of the stiffening girder of the bridge can provide reference for the construction of similar bridges.