大跨闭口钢箱组合梁组合桥面板有效宽度研究

Study on Effective Width of Composite Deck of Long-span Closed Steel-box Composite Girder

摘要:

为研究大跨度闭口组合钢箱梁组合桥面板的有效宽度系数变化规律，依托G1503高速公路跨吴淞江大桥建立了组合连续钢箱梁桥有限元模型，分析了不同桥梁跨度、不同箱室宽度下的跨中截面和中支点截面有效宽度系数变化规律，对比了钢桥面板和混凝土桥面板有效宽度的差异，给出了混凝土桥面板有效宽度系数建议取值。结果表明，组合桥面板的钢桥面板和混凝土桥面板横断面应力分布规律相似。钢桥面板的有效宽度与规范规定基本相等，跨中断面小约0.41%，支点断面小约4.13%；混凝土桥面板的有效宽度与规范规定差异较大，跨中断面小约3.25%，支点断面小约27.9%。组合桥面板的钢桥面板有效宽度比混凝土桥面板有效宽度大，跨中断面相差0.51%，支点断面相差5.9%，混凝土桥面板有效宽度系数可参考钢桥面板有效宽度系数折减0.9倍取值。

关键词:大跨度;闭口钢箱组合梁;组合桥面板;有效宽度

Abstract:

In order to study the variation law of effective width coefficient of the composite deck of long-span closed composite steel box girder, a finite element model of composite continuous steel box girder bridge is established by relying on G1503 Highway across Wusong River Bridge. The variation law of effective width coefficient of mid-span section and mid-fulcrum section is analyzed under different spans and chamber widths. The difference of effective width between steel deck slab and concrete deck slab is compared, and the suggested value of effective width coefficient of concrete deck slab is given. The results show that the transverse stress distribution of steel deck slab and concrete deck slab is similar. The effective width of the steel slab is basically equal to the specification, the mid-span section is about 0.41% smaller, and the fulcrum section is about 4.13% smaller. The effective width of concrete deck slab is greatly different from the specification, and the mid-span section is about 3.25% small, the fulcrum section is about 27.9% small. The steel deck effective width of the composite bridge deck is greater than the concrete deck effective width, the difference in the mid-span section is 0.51%, and the difference in the fulcrum section is 5.9%. The effective width coefficient of the concrete bridge deck can be reduced by 0.9 times by reference to the effective width coefficient of the steel bridge deck.

Key words:long span; closed steel box composite girder; composite bridge deck; effective width