Π型钢-混凝土结合梁由于其良好的受力性能和经济性，广泛应用于大跨径斜拉 桥中，但其气动性能相对略差，若设计不当则容易出现涡激振动现象，从而影响行车舒适性、 安全性或结构疲劳寿命等. 本文以广东潮汕大桥为实际工程依托，该桥为主跨205 m的独塔双 索面Π型钢-混凝土结合梁斜拉桥，开展了Π型钢-混凝土结合梁断面涡激振动及气动控制措 施研究. 首先，采用几何缩尺比为1∶50的主梁节段模型对该桥原设计方案主梁断面运营期涡 激振动进行了试验研究；然后，分别采用下稳定板、导流板、裙板、上稳定板等气动控制措施对 主梁涡激振动响应的控制效果进行了研究；最后，采用计算流体动力学方法（Computational Fluid Dynamics，CFD）对主梁断面最终采用气动控制措施机理进行了研究. 结果表明：主梁原 设计方案在设计风速范围内存在大幅涡激共振现象，涡激振动幅值超过规范限值；采用“三道 下稳定板+两侧竖向裙板+上中央稳定板”组合气动控制措施后，主梁涡激振动响应得到明显 抑制；该组合气动控制措施对Π型钢-混凝土结合梁涡激振动的控制机理主要表现为：设置三 道下稳定板可有效破坏Π型主梁下侧较大旋涡，Π型主梁两侧设置竖向裙板改善了其气动流 线型程度，设置上中央稳定板可有效阻止主梁上侧较大旋涡的运动.
Due to the excellent mechanical and economic performances of the Π-shaped steel-concrete compos? ite girder, it is widely used in long-span cable-stayed bridges. However, the aerodynamics performance of the girder is relatively poor, and the vortex-induced vibration (VIV) of the girder is prone to occur for the improper aerodynamic design, which affects driving comfort and safety, or structural fatigue. Based on Chao-Shan Bridge in Guangdong, a single-pylon cable-stayed bridge with a main span of 205 m and Π-shaped steel-concrete composite deck, the in? vestigations on the VIV and aerodynamic countermeasures of the Π-shaped steel-concrete composite deck were con? ducted. Firstly, the VIV of the original girder section in-service state was studied by applying wind tunnel tests of the rigid segment model with a length scale of 1∶50. Then, the effects of aerodynamic countermeasures on the VIV of the Π-shaped steel-concrete composite girder, such as the lower stability plate, the deflectors, the skirt plates, and the upper central stability plate were studied, respectively. Finally, the computational fluid dynamics (CFD) method was adopted to study the control mechanism of the aerodynamic countermeasures. The results show that there is a large vortex vibration of the original girder section within the design wind speed, and the peak value of the VIV exceeds the limit value of the specification. The VIV of the girder can be controlled remarkably with the combined countermea? sures of three lower stability plates, vertical skirt plates on both sides of the girder, and an upper central stability plate. The control mechanism of the combined countermeasures on the VIV of the Π-shaped steel-concrete compos? ite deck is mainly as follow: the three lower stability plates can effectively destroy the large vortexes on the lower side of the girder; the vertical skirt plates set on both sides of the girder can improve the aerodynamic streamline of the girder and the upper central stability plate can effectively prevent the movement of the larger vortexes on the top side of the girder.
刘志文 ,肖晗 ,王雷 ,盛捷 ,陈政清 .Π型钢-混凝土结合梁断面涡激振动及气动控制措施[J].湖南大学学报：自然科学版,2022,49(3):68~78复制