某上跨铁路桥梁涡振特性及气动优化试验研究

Study on vortex-induced vibration performance and aerodynamic optimization test of an overpass railway bridge

针对某上跨铁路桥梁进行风洞试验,探讨该桥梁带防抛墙主梁断面的涡振性能。相比带防抛网的主梁断面,该断面同样存在明显的涡振现象,且涡振性能更加恶劣。为抑制涡振,设置导流板、移动检修车轨道、封闭防撞栏杆、全封闭和有透风率的上中央稳定板及抑流板等气动优化措施对桥梁涡振特性的影响。研究结果表明:上中央稳定板和向内倾斜的抑流板为有效的抑振措施。对于上中央稳定板,随着高度增加,抑振效果增强;随着透风率的增加,抑振效果下降。当抑流板宽度和上中央稳定板高度数值均较大时,其组合效果优于单一措施的效果。研究结果可为同类型桥梁的抗风设计提供借鉴。

Wind tunnel tests are carried out on an overpass railway bridge to investigate the vortex-induced vibration(VIV)performance of the main beam section with anti-throwing wall.The test results show that compared with the main beam section with anti-throwing net,the VIV phenomenon is obvious as well for this section.Moreover,the VIV performance is worse.In order to suppress the VIV,several aerodynamic optimization measures are discussed,including setting the flow guide plate,moving the track of the repair car,sealing the anti-collision railings,setting the upper central stability plate with whole sealing or air permeability,setting the flow suppression plate and so on.It is found that the upper central stability plate and the flow suppression plate with inward tilt are effective measures for the suppression of VIV.As for the upper central stability plate,the suppression effect becomes better for larger height.In addition,the effect is worse under the increase of the air permeability.When the width of the flow suppression plate and the height of the upper central stability plate are larger simultaneously,the effect of their combination is prior to that of either of them.The results can provide reference for wind-resistant design of this kind of bridge.