Research On Type Selection And Windproof Performance Of Fully Enclosed Wind Barrier Structure Of High-speed Railway Girder Bridge

In recent years,with the rapid development of my country’s high-speed railways,the speed of the train has also continued to increase.When the high-speed train reach windy areas,the accident of derailment and overturning often occurs.The installation of wind barriers can effectively solve this problem.Based on the basic theory of computational fluid dynamics,this paper uses CFD numerical simulation method to study the structure selection and windproof performance of the completely enclosed wind barrier of high-speed railway bridges.The main tasks completed include:(1)The current development status of high-speed railway wind barriers at home and abroad and related research results are summarized,and the basic principles and methods of CFD numerical simulation are introduced.At the same time,the use of Fluent software is briefly introduced.(2)Using Fluent software,a two-dimensional numerical model of the vehiclebridge-wind barrier system is established.According to the model establishment process,the calculation area selection,meshing method,and boundary condition setting principles suitable for the research object of this paper are analyzed.On this basis,the three-component force coefficients of the wind barrier,the main girder and the train are calculated separately when the circular and square fully enclosed wind barriers are installed.By comparing the calculation results,it is found that the circular fully enclosed wind barrier has better aerodynamics performance.(3)Taking the circular fully enclosed wind barrier with better aerodynamic performance as the research object,the Fluent software is used to establish a CFD numerical model,and the calculation and analysis of the setting of the circular fully enclosed wind barrier with different air permeability and the height of the wind barrier affect different positions on the inner bridge deck of the wind barrier.According to the influence law of the wind field,the reasonable value range of the effective air permeability of the circular fully enclosed wind barrier and the reasonable value of the effective height of the wind barrier are given.(4)Finally,the characteristics of the wind pressure distribution on the inner and outer surfaces of the circular fully enclosed wind barrier are discussed,and the wind pressure distribution rules on the wind barrier surface at different wind direction angles are obtained.At the same time,the recommended value of the wind pressure coefficient for the structure’s wind resistance design is given.