| Presently,traditional rail tracks constructed by rail joints were replaced with continuously welded rails(CWR).Consequently,the occurrence of track buckling is intensified due to the expansion of the rails.Track buckling might be caused by thermal loads called “static buckling” or the simultaneous effect of thermal and train braking/acceleration called“dynamic buckling”.The lateral resistance of ballasted tracks is an important factor in preventing lateral track buckling,governed by different components,including the ballast track profile and properties and sleeper specifications.Several strategies have been introduced so far to enrich ballasted tracks’ lateral stability.In this study,Single Tie Push Tests(STPTs)were selected as a standard method to assess the performance of various sleepers on a ballasted track panel with different shoulder ballast widths and heights.Monoblock sleepers,biblock sleepers,ladder sleepers,winged sleepers are the selected concrete sleepers,and Y-shaped and conventional steel sleepers are selected steel sleepers in this study.In addition,the effect of fasteners loss on the lateral track resistance was evaluated using Lateral Track Panel Tests(LTPTs).Apart from experiments,the modeling of STPTs was executed using the Discrete Element Method(DEM)to perform the sensitivity analysis on the influence of ballasted track components on the lateral track resistance.In this regard,the creation of ballast particles,calibration,and verification of models was explained for each experiment in detail.To be brief,considering the effect of the sleeper type on lateral track resistance and sleeper components contribution,providing a calibration method for DEM simulation of ballast particles as a cluster of spherical pebbles,and evaluation of the impact of railway fasteners loss on lateral track resistance are innovative ideas of the present study. |
