不同风嘴形式分体箱梁桥梁的静力风致稳定性能

发布时间：2018-03-20 16:08

本文选题：分体箱梁　切入点：开槽率　出处：《土木工程学报》2016年06期 　论文类型：期刊论文

【摘要】：作为大跨径以及超大跨径桥梁一种新兴的断面形式,分体箱梁可以改善空气动力性能和提高颤振临界风速,但是还需要保证其静力风致稳定性能,研究了不同风嘴形式下分体箱梁的静力三分力系数和静力风致稳定性能随开槽率的演变规律。结果表明:两种风嘴形式分体箱梁的阻力系数随开槽率增加而增大,采用断面实体宽度为无量纲化标准时断面升力系数绝对值会随开槽率的增加而增加,这与采用断面总宽为无量纲化标准时结果相反,升力矩系数绝对值会随着开槽率的增加而减小,但这种规律性会受到风攻角的影响;风嘴对称性的变化仅改变断面阻力系数随开槽率的变化规律;两种计算模型下,对称风嘴断面分体箱梁桥梁跨中的各向位移绝对值和静力风致失稳临界风速随开槽率的变化规律完全相反,而不对称风嘴断面的各向位移变化规律相似但也有区别;总体上对称风嘴断面的最低静力风致失稳临界风速要高于不对称风嘴断面;考虑结构刚度变化会使断面开槽后静力风致失稳临界风速随着开槽率的增加而升高并超过不考虑刚度变化时的相应值,故对分体箱梁静力风致稳定性能分析时需要考虑开槽率不同带来的结构刚度变化。
[Abstract]:As a new cross-section form of long-span and super-span bridges, the separated box girder can improve the aerodynamic performance and the flutter critical wind speed, but it also needs to ensure the static wind-induced stability. The evolution law of static three-point force coefficient and static wind-induced stability performance with slotted rate of split box girder under different wind nozzles are studied. The results show that the drag coefficient of two types of split box girders increases with the increase of slotted ratio. When the sectional solid width is dimensionless, the absolute value of section lift coefficient will increase with the increase of slot rate, which is contrary to the result when the total section width is dimensionless. The absolute value of lift torque coefficient will decrease with the increase of slotting rate, but this regularity will be affected by wind attack angle, the change of wind nozzle symmetry will only change the variation law of cross section resistance coefficient with slot rate. The absolute value of displacement in the span of symmetrical wind nozzles and the variation law of critical wind speed caused by static wind instability with slotted rate are completely opposite, while the variation laws of displacements in different directions of asymmetric wind nozzles are similar but different. On the whole, the critical wind speed of the minimum static wind instability is higher than that of the asymmetric wind nozzle section. Considering the change of structural stiffness, the critical wind speed of static wind-induced instability increases with the increase of slotting rate and exceeds the corresponding value when the stiffness change is not taken into account. Therefore, the structural stiffness change caused by the different slotting ratio should be considered in the static wind induced stability analysis of the split box girder.
【作者单位】：同济大学土木工程防灾国家重点实验室;
【基金】：科技部国家重点基础研究计划(973计划)(2013CB036300) 国家自然科学基金(5107827,91215302) 国家重点实验室自主课题(SLDRCE 10-B-05) 交通行业重点实验室自主课题(KLWRBMT-04)
【分类号】：U441.3

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