温度作用下大跨度钢-混组合梁剪力滞效应研究

Research on Shear Lag Effect of Large⁃span Steel⁃concrete Composite Beams Under Temperature Action

以新建包头至银川高铁中包头至惠农段BYZQ-7标磴口黄河特大桥为研究对象,考虑温度变化对钢-混组合梁的剪力滞影响,求解其温度应力,并建立温度剪力滞系数。通过温度传感器监测全天温度,运用现场实测方法,研究钢-混组合梁温度场分布规律,并计算分析温度作用下,钢-混组合梁的剪力滞效应时程曲线。结果表明,钢-混组合梁温度变化与环境空气温度升降过程一致,温度场分布不均。温度突变对钢-混组合梁的剪力滞系数影响显著,顶板与腹板交接处剪力滞系数峰值为底板与腹板交接处剪力滞系数峰值的163倍。

Taking the new Dengkou Yellow River Bridge in BYZQ-7 section of Baotou-Huinong section of Baotou-Yinchuan High-speed Railway as the research object,considering the influence of temperature change on the shear lag of steel-concrete composite beams,the temperature stress is solved,and the temperature shear lag coefficient is established.The temperature sensor is used to monitor the all-weather temperature,and the field measurement method is used to study the temperature field distribution law of the steel-concrete composite beam,and the shear lag effect time history curve of the steel-concrete composite beam under the action of temperature is calculated and analyzed.The results show that the temperature change of the steel-concrete composite beam is consistent with the temperature rise and fall process of the ambient air,and the temperature field distribution is uneven.The temperature mutation has a significant effect on the shear coefficient of the steel-concrete composite beam.The peak value of the shear lag coefficient at the junction of the top plate and the web is 1.63 times that of the shear lag coefficient at the junction of the bottom plate and the web.