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Study on Aerodynamic Stability of Super-long Spanned Bridge and Its Structural Dynamics

超长跨桥梁气动稳定性及其结构动力学研究

基本信息

批准号：
62460149
负责人：
SHIRAISHI Naruhito
金额：
$ 3.84万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

Main problem in the design of superstructure of long-span bridge is the aerodynamic stability. Therefore, it is an essential task to know the behavior of natural wind at the construction site as well as its aerodynamic properties.In this research study, by using the failure probability index of the bridge structure to aerodynamic response, the first stage of failure due to flutter was determined as an object of the failure probability in 1987. The vortex-induced oscillation was also objected. In 1988, failure probability in 1987. the vortex-induced oscillation was also objected. in 1988, failure probability was determined with the consideration of both the effect of vortex-induced oscillation and buffeting, and damage accumulation resulting from fatigue was also determined in order to evaluate fatigue failure.Furthermore, for evaluating natural wind, because both an aerodynamic behavior of bridge structures and the characteristics of natural wind are strongly depended on the wind direc … More tion, wind speed characteristics of strong and normal wind were determined for each wind direction.From these results, failure probability of seven suspension bridges due to flutter under strong wind were determined. For double-deck bridges, the thickness of web and flange of chord member is thicker than other bridges, and the result of the evaluation fell in the safety side. For boxgirder bridge, based on the characteristics of vibration response obtained from wind tunnel test, the method for evaluating failure probability due to both vortex-induced oscillation and buffeting is proposed. Evaluated result by using this method showed that the failure probability depends mainly on the first mode of vortex-induced oscillation. It was also found that the failure probability is extremely sensitive to the material strenght.For estimating strong wind, the wind data of the 133 places in Japan for 15 years were used. Region of strong wind, Weibul parameter, and typhoon factor were determined. Finally, the map of typhoon factor was established.From this research, the characteristics of natural wind and the evaluation of its effect on the structural stability were proposed. This results are considered to be useful for evaluation of the aerodynamic stability of the long-span bridge. Less

大跨度桥梁上部结构设计的主要问题是气动稳定性。因此，了解施工现场的自然风的特性及其空气动力特性是一项重要的课题。本研究中，利用桥梁结构的空气动力响应的失效概率指标，以1987年确定的颤振失效的第一阶段为失效概率的对象。涡激振荡也遭到了反对。1988年，1987年的故障概率。涡激振荡也遭到了反对。1988年提出了考虑涡激振动和抖振影响的失效概率和疲劳损伤累积的方法，并对自然风作用下的桥梁结构进行了分析，提出了一种新的计算方法，该方法不仅可以用于桥梁结构的疲劳失效分析，而且可以用于桥梁结构的气动特性和自然风特性的分析。 ...更多信息通过对7座悬索桥在不同风向下的颤振失效概率的分析，确定了7座悬索桥在不同风向下的强风和正风的风速特性。双层桥面桥梁的弦杆腹板和翼缘厚度较其他桥梁大，评价结果处于安全范围内。针对箱形梁桥，基于风洞试验获得的振动响应特征，提出了涡激振动和抖振共同作用下桥梁失效概率的评估方法。计算结果表明，失效概率主要取决于涡激振动的第一阶模态。同时发现失效概率对材料强度极为敏感。在估计强风时，使用了日本133个地方15年的风数据。确定了大风区、威布尔参数和台风因子。最后，建立台风因子图，并据此提出自然风的特性及其对结构稳定性影响的评估。研究结果可为大跨度桥梁的气动稳定性评估提供参考。少