Experimental and numerical study on lateral resistance of frictional sleeper with arrowhead groove

Guoqing Jing,Wenli Jia,Xinyu Wang,Valeri Markine,Roar Nålsund,Yunlong Guo

doi:10.1016/j.trgeo.2021.100638

Abstract

To enhance the stability of continuous welded rail (CWR) tracks, frictional sleepers have been developed. The frictional sleepers are new types of sleepers with grooves on the bottom, and different bottom grooves improve lateral resistances at different magnitudes. In this study, single sleeper push test (SSPT) and its model with discrete element method (DEM) were carried out to confirm how much arrowhead groove frictional (AGF) sleeper increases the lateral resistance of ballasted track. The SSPTs were performed to confirm the lateral resistance results, and also to validate and calibrate the DEM models. With the validated models, the groove factors influencing the lateral resistances were studied, including groove sizes (depth, width), arrowhead groove direction and groove numbers. The reason of lateral resistance improvement was studied at mesoscopic level, including the ballast-sleeper contact numbers and contact force chains. Results show that applying the AGF sleeper is able to improve lateral resistance by 7–24%, and it can provide enough lateral resistance after reducing ballast shoulder width from 500 mm to 300 mm. The AGF sleeper can improve the sleeper-ballast interaction by increasing sleeper-ballast contact number. The study is helpful for frictional sleeper design, further improving track stability.

Highlights

Ballasted track is a common railway structure that is widely-used worldwide with many advantages, e.g. low construction cost, easy maintenance and high transportation capability [1,2]
Single sleeper push test (SSPT) and its model with discrete element method (DEM) were carried out to confirm how much arrowhead groove frictional (AGF) sleeper increases the lateral resistance of ballasted track
Results show that applying the AGF sleeper is able to improve lateral resistance by 7–24%, and it can provide enough lateral resistance after reducing ballast shoulder width from 500 mm to 300 mm

Summary

Introduction

Ballasted track is a common railway structure that is widely-used worldwide with many advantages, e.g. low construction cost, easy maintenance and high transportation capability [1,2]. For increasing train speed and axle load, the majority of the jointed tracks have been changed to the CWR tracks in the last decades all over the world [3,4,5,6,7]. The CWR track has become the typical modern track structure with plenty of advantages [8]. The track buckling normally happens at the lateral direction, while it sometimes appears at the vertical di rection. This phenomenon is mainly induced due to the rail temperature change and train accelerating or braking, the ballast bed is not able to provide enough lateral resistances to the sleepers. Particu larly, it becomes severer when there exists the rail eccentricity because of the track irregularities at some special areas (bridges, bends and tunnels)

Methods

Results

Conclusion