叶片式导风屏障的高度优化研究

Research on the Height Optimization of Blade-type Wind Guide Barrier

研究目的:在混凝土桥上安装叶片式导风屏障时,通常需要在桥面设置一定高度的基础,基础高度和导风叶片高度共同参与挡风;基础过高,会增加桥梁自身荷载;导风叶片过高,则会增大导风屏障自身受力,制造成本也会增高。因此,本文旨在通过风洞试验,研究叶片式导风屏障总高度、导风叶片高度以及基础高度对列车气动力系数、列车周围的风压系数以及轨道中心线处风速的影响规律,旨在得到叶片式导风屏障各高度对列车运行安全及桥梁受力的影响,为工程应用时各高度的选取提供依据。研究结论:(1)桥面安装导风屏障后,列车周围风压系数、列车三分力系数以及轨道中心处风速均有所降低,对提高桥梁的安全行车有积极作用;(2)能够兼顾挡风性能和经济性的叶片式导风屏障最佳总高度在3~3.5 m之间;(3)导风屏障基础高度的增加对挡风效果的贡献不明显,在满足列车安全舒适运行需求的同时,应尽可能降低基础高度;(4)实际工程导风屏障高度还应结合车速、风速,通过风-车-桥耦合振动分析进一步验证;(5)本研究成果可为叶片式导风屏障高度的选取提供初步依据。

Research purposes:When installing a blade-type wind barrier on a concrete bridge,usually need to set a certain height of foundation on the bridge deck.The height of the base and the height of the wind guide blades participate in windshield together.If the foundation is too high,it will increase the load of the bridge itself;if the wind guide blade is too high,it will increase the force of the wind guide barrier itself,and also increase the manufacturing cost.So,this paper aims to study the effect of the total height of the blade-type wind guide,the height of the wind guide blades and the base height on the aerodynamic coefficient of the train,the wind pressure coefficient around the train,and the wind speed at the centerline of the track through the wind tunnel test,obtain the effect of each height of the blade-type wind barrier on the safety performance of trains and bridges,which provides a basis for the determination of each height during engineering application.Research conclusions:(1)Installation of wind barrier reduces the wind pressure coefficient around the train,the three-component force coefficient of the train,and the wind speed at the track,which has a positive effect on improving the safe driving of the bridge.(2)The best overall height of the wind-guiding barrier that can take into account wind-shielding performance and economy is between 3〜3.5 m.(3)The increase in base height does not contribute significantly to the windshield effect.While meeting the requirements of safe and comfortable train operation,the base height should be reduced as much as possible.(4)The height of the actual engineering wind barrier should also be combined with vehicle speed and wind speed,and further verified by wind-vehicle-bridge coupled vibration analysis.(5)The research results can provide a preliminary basis for the selection of the height of the blade-type wind barrier.