Study On Settlement Characteristics Of Ballast Bed Of High Speed Railway Train

The railway is one of the important infrastructures of a country,and it is also the lifeblood of a country’s development.With the development of heavy load and high-speed railways,ballasted tracks still occupy a large proportion of domestic railways due to its unique advantages.However,during the operation of high-speed railways,with the increase number of trains running,the safety of railway operation will be decreased.At the same time,the comfort of passengers will be affected.Because the ballasted track is a granular ballast bed,so there has poor rigidity,and it is prone to subsidence.Moreover,with the long-time operation of high-speed trains,the ballast breakage,pulverization,and splash become serious.In response to this problem,this paper uses a combination of experiment and simulation to carry out related research on the cumulative settlement deformation of ballast beds in high-speed railway and the working state of the ballast bed,which providing a certain reference for the design,maintenance,and maintenance of ballast beds in high-speed railway.In the process of establishing a discrete element simulation model,in order to balance the accuracy of the model and the cost of the experiment,three-dimensional reconstruction method was used to obtain ballast particle model in this paper.Ballast particles will be scanning by the Visual SFM software and modeling by the Meshlab software.After that,the 3D grid model of ballast particles will be generated.Then,a particle model close to the actual ballast shape will established by the 3D gird model of ballast particles is introduced into the discrete element software PFC3D5.0.In addition,a ballast box discrete element simulation model is established based on relevant design standards of China’s high-speed railway.The reliability of the discrete element model needs to be verified before it is simulated.The paper designs and builds a test platform consistent with the discrete element model and using the same grading standard and sleepers to fill the ballast box.Compared the two results,and the discrete element model is adjusted to ensure the reliability and feasibility of the discrete element model.Through the simulation analysis of the discrete element model,the cumulative settlement and working conditions of ballast bed in high-speed railway in different train speeds are obtained.Meanwhile,it is exploring the effect laws of ballast bed cumulative settlement and working status in different ballast friction coefficients and different ballast bed density.The research results show that the train speed and other parameters have an important influence on the settlement of the track bed.During the operation of the railway,it is necessary to attach great importance to the negative effects of parameters such as train speed on the settlement and working status of the track bed.The relevant conclusions drawn in this paper through experiments and simulations can provide a certain reference for the changes in some parameters of high-speed railways,and at the same time it provides a certain reference value for the related research of ballast beds in high-speed railway.