Study On The Longitudinal Force Transfer-mechanism Of Ballasted Track On The Bridge

In the process of railway development,ballasted track is an important structure and it is the first to be used in railway construction.It has a lot of engineering advantages.However,due to the complex mechanics of the structure,the key issues are not sufficiently solved,which has led to its decreasing attention in the construction of high-speed railways that constantly emphasize speed and accuracy.In this paper,according to the shortcomings of the current research on the continuous rails of the ballasted track on the bridge,it has a comprehensive comparative analysis of the calculation method of the ballasted track on the bridge.It also has a further study on the interaction between the rails and the traditional ballasted track on the bridge.Establishing a ballasted track model on the bridge in use of discrete element method.The effect of bridge expansion on the ballast bed and the influence of the ballast bed on the rail expansion force were studied.The main researches are as follows:(1)Analysis the effect of ballast bed parameters to longitudinal interaction.In the selection of ballast bed parameters,the main researches are on the ballast grading,ballast surface friction coefficient,ballasted bed density.It studies the influence of these three parameters on the four aspects as the ballast ball contact force,ballast displacement,ballast force distribution and the rail expansion force.(2)Analysis the effect of the sleeper parameters to longitudinal interaction.In the sleeper form,the three types of sleepers,including type III sleeper,wide sleeper and frame sleeper were used to study the influence on the ballast ball contact force,the ballast displacement,the distribution of the ballast force and the rail expansion force.(3)Analysis the effect of beam parameters to longitudinal interaction.It explains the influence of the beam parameters on the contact force of the ballast particles,the ballast displacement,the distribution of the ballast force and the rail expansion force.A detailed comparison of rail expansion force was made between ballast-less track and ballasted track.