钢-混凝土叠合板组合连续梁桥收缩徐变效应分析

Analysis of Shrinkage and Creep Effect of Steel-concrete Composite-slab Girder Bridge

以某市高架快速路(40 m+55 m+40 m)钢-混凝土叠合板组合连续梁桥为工程背景,采用有限元分析计算其收缩徐变效应。分析结果表明:因预制板和现浇板加载龄期的差异而产生的混凝土收缩徐变差异,会引起现浇板、预制板和钢梁之间的应力重分布;叠合板组合梁的桥面板收缩徐变应力约是现浇板组合梁的0.82~0.97倍,成桥后钢梁应力前者约是后者的0.80~0.94倍,叠合板对混凝土收缩徐变的“抑制”作用明显。

Taking the 40 m+55 m+40 m steel-concrete composite-slab girder bridge of an urban elevated expressway as the engineering background,its shrinkage and creep effects are calculated by the finite element analysis.The analysis results show that the difference of concrete shrinkage and creep caused by the difference of loading age between the precast slab and cast-in-place slab will cause the stress redistribution among the cast-in-place slab,precast slab and steel beam.The shrinkage and creep stress of the bridge deck with the composite-slab girder is about 0.82~0.97 times that of cast-in-place composite-slab girder.And the stress of steel girder of the former after the bridge completion is about 0.80~0.94 times that of the later.The"inhibition"effect of the composite slab on the shrinkage and creep of concrete is obvious.