Experimental Investigation On Aerodynamic Characteristics Of Train-bridge System And Influence Of Wind-break Wall Under Strong Wind

Flow around train and bridge section is changed dramatically by high-speed train running on the bridge, thus train-bridge system is subject to a more unfavorable wind environment. Investigation on aerodynamic characteristics of train-bridge system and influence of wind-break wall is of great significance to ensure train’s safety and bridge serviceability. With support of the National Natural Science Foundation Project of China (NO.51178471and51322808), taking CRH2high-speed train,32m simply supported box girder at Beijing-Shanghai high-speed railway and double-side porous wind-break wall as experiment models, the scale ratio of1:25is selected, relying on wind tunnel test system of Central South University, mutual aerodynamic interference of train-bridge system and influence of wind-break wall are investigated by pressure test.(1) Basic principles of wind tunnel test are explained, then dimension parameters of the test train, simply supported box girder and wind-break wall, pressure test points of train and bridge are introduced. Experimental methods and data processing principles in this thesis are discussed.(2) Force test method is conducted to verify the accuracy and precision of pressure test method, it is proved to be feasible to investigate aerodynamic characteristics of train and bridge by pressure test method. Influence of different train model combinations are investigated, the results indicate that two combinations can meet the test requirement. Under transverse wind, pressure tests of the train are conducted with different positions in longitudinal and horizontal bridge deck to investigate the influence of the bridge location and wind-break wall’s height and ventilation rate on the train’s aerodynamic characteristics. And a reasonable wind-break wall’s height is selected.(3) Pressure tests of the train-bridge system are conducted under crosswind, research contents include:Reynolds effect of the train’s aerodynamic characteristics, mutual aerodynamic interference of the train-bridge system and influence of wind-break wall on aerodynamic characteristics of train and bridge under different wind angles.