Simulation Study On Nonlinear Resistance Of Ballast Track Seamless Track Under The Effect Of Track

Ballast track is one of the main structural forms of seamless track at present,and it is widely used in various environments because of its strong adaptability.The application of seamless line in bridge section,turnout area,curve section and other special sections is more demanding to the study of resistance of ballast bed.Under the influence of load diversity and track structure style,the above section is more likely to have the change of track bed state,which puts forward the research need on track frame level for track bed resistance.Therefore,this article established by five discrete element have a frantic jumble of sleeper,ballast over a couple of sleepers section of track structure have a frantic jumble of roadbed,the mechanics characteristics of contact and movement characteristic analysis,determine the sleeper load quantity,track section and sleeper quality of lateral shear behavior of ballast macro and detailed change characteristic,the concrete research content is as follows:1.In this paper,the horizontal and vertical loading of the railway track structure composed of multiple sleepers was carried out,and the mechanical properties,contact properties and motion characteristics of the railway track under the influence of different load quantities of sleepers were compared.It was found that:,(1)considering the loading of multiple sleepers would lead to the reduction of the resistance in the horizontal and vertical direction of the railway track bed.(2)due to the overall impact of the track structure,the transverse loading of the ballast shoulder,longitudinal loading of the pillow parts in the contact characteristics of the two are affected greatly,the number of coordination and the characteristics of the contact point change significantly.(3)for the transverse load of the ballast shoulder,longitudinal load of the pillow for motion characteristics.It is found that when considering the loading quantity of sleeper,it will lead to the loosing of ballast and the increase of kinetic energy,and the phenomenon of sliding and flying ballast is more likely to occur.In the longitudinal shear behavior,the ballast on the side of the sleepers will increase the coordination number and decrease the kinetic energy with the increase of the loading root number of the sleeper,which is easy to cause the overall longitudinal movement of the sleeper.2.The ballast bed with 100 mm pile height on the shoulder and 100 mm pile height on the sleeper was set up to study the transverse and longitudinal shear behaviors of the ballast bed respectively,so as to determine the influence of the change of ballast quantity on the track effect.The research found that:(1)The pile height of ballast shoulder has a great influence on the transverse shear behavior of the ballast bed,which not only affects the resistance of the pillow end,but also affects the growth of the resistance of the pillow side.Different levels of ballast shoulder will have different effects on the contact characteristics and movement characteristics of ballast bed,and more ballast shoulder ballast is more susceptible to the influence of track action.(2)Ballast is a key factor that affects the longitudinal shear behavior of ballast bed.Comparatively speaking,a sufficient ballast can provide a large longitudinal resistance,which is more susceptible to the influence of the track effect.Also must take into account the case of less ballast under the pillow side ballast easy to loose,the corresponding movement of the growth of the characteristics of the faster.3.Through the method of changing the sleeper density to study the influence of different sleeper quality on the transverse shear behavior of the track bed,the research found that:(1)The sleeper quality can effectively increase the size of the sleeper longitudinal and lateral resistance,the main source of the increase in the transverse resistance is the pillow bottom component resistance.(2)The increase of sleeper mass can not only increase the vertical stress,but also effectively change the size of the ballast at the bottom of the sleeper,reduce the vertical displacement of the sleeper,maintain the stability of the frame structure.