大跨桥梁主梁风致稳定性被动气动控制措施综述

Review on Passive Aerodynamic Countermeasures on Main Girders Aiming at Wind-induced Stabilities of Long-span Bridges

颤振和涡振是大跨桥梁风致振动控制的核心研究对象,而被动气动控制措施是当前最常用的抑振方法。为了提高气动选型和优化的效率,系统调研了既有的颤振、涡振被动气动控制措施,发现对于有类似气动特性的主梁,被动气动控制措施在颤振、涡振控制方面存在较明显的趋同性。在选择颤振、涡振气动控制措施时,有必要紧密结合主梁气动外型分类。为此,基于大跨度桥梁中最常见的4种主梁类型(双边主梁、整体式箱梁、分体式箱梁以及桁架梁),综述了被动气动控制措施在改善主梁颤振、涡振性能时的优化思路,提出了基于气动附属物(稳定板、格栅、风障、翼板、分流板、裙板、导流板、隔流板等)的形状和位置优化原则,推荐了考虑主梁固有外形(主梁开槽、槽内倒角、设计风嘴、调整栏杆和检修轨道形式)的附加构件尺寸设置策略。研究结果可为大跨度桥梁主梁选型设计阶段提供气动选型方面的参考和借鉴。

Flutter and vortex-induced vibrations(VIVs) are two core elements for the wind-induced vibration control oflong-span bridges. At present, the most commonly used vibration suppression method is passive aerodynamic control. In order to improve the efficiency of aerodynamic shape selection and optimization, the existing passive aerodynamic controls on flutter and VIVs were systematically investigated. If the aerodynamic characteristics of main girders are similar, there is anobvious consistency in the flutter and VIVs under passive aerodynamic control. Moreover, the aerodynamic shape of the main girder should be classified when choosing the aerodynamic control on the flutter and VIVs vibration. Here, the aerodynamic characteristics of four main girder types(bilateral, integral box, split box and truss) used in long-span bridges were considered. Some optimization ideas for the application of passive aerodynamic controls, to improve the flutter and VIVs performance of long-span bridge girders, have been summarized. The principle of shape-position optimization based on aerodynamic appendages(e.g., stabilizer plate, grille, wind barrier, winglet, separator, skirt plate, guide vane, flow-isolating plate, etc) is proposed, in combination with the dimensional setting method of additional components that considers the main girder’s inherent shape(i.e., slotting, chamfering, design of the wind fairing, adjusting railings, and maintenance track, etc). Overall, this work provides important information for the aerodynamic selection of main girders during the preliminary design of long-span bridges.