超宽双边箱钢主梁剪力滞效应的试验研究和敏感性分析

Experimental Study and Sensitivity Analysis of Shear Lag Effect of Ultra-wide Double-sided Box Girder

为探究双边箱梁在不同参数条件下剪力滞效应的主要影响因素,以云龙湾大桥为依托,通过现场足尺原位试验,在实桥中布设4个测试截面,结合有限元软件ANSYS,建立全桥梁-壳模型进行对比分析。结果表明:剪力滞系数于双边主梁和主梁顶板交接处达到最大。截面的剪力滞系数从双边箱到桥面中心线呈先减小后增大的变化规律,剪力滞系数于桥面中心线处达到极大值。吊索和横梁能有效减小剪力滞系数;偏心荷载作用时,偏心一侧剪力滞系数明显增大,另一侧显著减小。

In order to explore the main influencing factors of shear lag effect of bilateral box girder under different parameters,based on Yunlongwan Bridge,through full-scale in-situ test,four test sections were set up in the real bridge,and the full bridge-shell model was established with finite element software ANSYS,for comparative analysis.The results show that the shear lag coefficient reaches the maximum at the junction of the bilateral main beam and the roof of the main beam.The shear lag coefficient of the section first decreases and then increases from the double-sided box to the centerline of the bridge deck,and the shear lag coefficient reaches the maximum at the centerline of the bridge deck.Slings and beams can effectively reduce the shear lag coefficient;under eccentric load,the shear lag coefficient increases obviously on one side of the eccentricity and decreases on the other side.