武汉大道跨铁路斜拉桥主跨现浇段支架设计  

Design of Scaffolding for Cast-in-Situ Segments of Main Span of Wuhan Avenue Cable-Stayed Bridge Spanning Railway

作　　者：王吉连 陈开桥 毛伟琦 

机构地区：[1]中铁大桥局第七工程有限公司,湖北武汉430050

出　　处：《桥梁建设》2013年第3期103-108,共6页Bridge Construction

摘　　要：武汉大道跨铁路桥采用独塔双索面预应力混凝土箱梁斜拉桥,跨度布置为138m+81m+41m。该桥主跨MB15～MB21节段桥面宽度由47.680m渐变至50.499m,采用支架法现浇施工。现浇支架设计为桩柱式四跨连续梁结构,主要由基础、立柱、柱顶横梁、贝雷梁、防护结构等组成,其中立柱顺桥向设5排,横桥向设8排(Z1～Z3)和6排(Z4、Z5)。为检验施工阶段现浇支架及中跨合龙时主梁主体结构的安全性,采用MIDAS软件建立主梁MB15～MB21节段与支架的整体模型,计算支架主要结构的受力及变形;建立主梁现浇段悬臂端模型,计算合龙段施工前主梁现浇段悬臂端的主拉应力和位移,计算结果表明施工阶段现浇支架及合龙时主梁的安全性均满足规范要求。Wuhan Avenue Bridge Spanning Railway is a prestressed concrete box girder cable-stayed bridge with single pylon and double cable planes and with span arrangement 138 m＋81 m＋41 m. The deck width of the segments MB15~MB21 of the main span of the bridge varies gradually from 47.680 m to 50.499 m and the segments are cast in situ by the scaffolding method. The scaffolding for the cast-in-situ construction is designed as a 4-span continuous beam structure of pile and post type and is mainly composed of the foundations, posts, post top cross beams, bailey truss and protection structure. In the longitudinal direction of the bridge, 5 arrays of the posts are arranged while in the transverse direction, 8 arrays （Z1~Z3） and 6 arrays （Z4, Z5） of the posts are arranged. To check the safety of the scaffolding at construction stages and the principal structure of the main girder at closure time of the main span, the software MIDAS was used to set up the integral model for the segments MB15~MB21 and the scaffolding of the main girder and the force conditions and deformation of the principal structure of the scaffolding were calculated. The model for the cantilever end of the cast-in-situ segments of the main girder was set up as well and the principal tensile stress and displacement of the cantilever end before construction of the closure segment was calculated. The results of the calculation indicated that the safety of the scaffolding at the construction stages and the main girder at the closure time could all satisfy the relevant requirements in the codes.

关 键 词：斜拉桥 跨线桥 箱形梁 预应力混凝土结构 现浇施工 支架设计 

分 类 号：U445.35[建筑科学—桥梁与隧道工程]