Experimental analysis of ballast bed state in newly constructed railways after tamping and stabilizing operation

Before the operation of newly constructed railways, tamping and stabilizing machines should be used to improve the quality of ballast beds. With the expansion of the railway network and increase of speeds and axle loads, higher quality and efficiency for tamping and stabilizing operation are required. However, previous studies did not involve...

Discrete Element Analysis on Mechanical Properties of Ballast Bed by Tamping in Railway Turnout Areas

Turnout is the key component of the railway tracks for trains to change direction, which is vital to operational safety and passenger comfort. Therefore, it is of great importance to perform a scientific and reasonable tamping operation for turnout areas. In this paper, based on the commercial software EDEM and RECURDYN, a coupled simulation...

Structural analysis and parametric study ballasted track in sandy regions

The sand intrusion in railway tracks in sandy regions can significantly change the mechanical behaviour of tracks and thus threaten the safety of train operation. This paper presents substantial field tests on both sandy and clean railway tracks to study the effect of sand intrusion on the longitudinal resistance of ballast bed and the...

Experimental study and discrete element analysis on lateral resistance of windblown sand railway

The lateral resistance of ballast bed is an important parameter to prevent track expansion and maintain track stability. The invasion of sand particles can cause the change of lateral resistance of ballast bed and affect the stability of track structure, but little attention has been paid to the change characteristics of nonlinear lateral...

Mechanical behaviour and energy evolution of polyurethane-mixed ballast under revised bonding constitutive model

The bonding contact presents complex modes in polyurethane-mixed ballast. The commonly used parallel bond model is revised and four different contact models are developed including Ballast-Ballast Contact Bonding, Ballast-Ballast Noncontact Bonding, Ballast-Sleeper Contact Bonding, and Ballast-Sleeper Noncontact Bonding. The mechanical...

Systems thinking approach for improving maintenance management of discrete rail assets: a review and future perspectives

Performance evaluation and maintenance planning are gaining importance with ageing rail infrastructure and increasing demand on track safety and continuous availability. The discrete/point railway assets (e.g. bridges, level crossings) together with extended track sections constitute the main railway network infrastructure. The former has...

Study of loaded versus unloaded measurements in railway track inspection

To ensure railway operations safe, track geometry parameters, e.g., track gauge, are usually inspected using track geometry cars. The measurement frequency of track geometry cars is low (twice per year) due to high operational costs and track possession. An innovative way to perform track inspection at high frequency and affordable cost is...

Numerical investigation of the behavior of stone ballast mixed by steel slag in ballasted railway track

Recently, implementing steel slag ballast has been proposed as an appropriate material to substitute stone ballast. In this regard, one of the technical concerns is the behavior of steel slag ballast in both time and frequency domains that needs to be assessed, properly. Furthermore, the combination of stone ballast and steel slag is...

Analysis on mechanical characteristics of welded joint with a new reinforced device in high-speed railway

High-speed railways adopt continuous welded rail to maintain the smoothness and continuity of the rail surface. However, the welded joint became one of the weakest parts. In order to clear the characteristics and mechanical properties of the new reinforced device, a dynamic three-dimensional vehicle-reinforced device-track coupling model is...

Influence of wheel polygonal wear on wheel-rail dynamic contact in a heavy-haul locomotive under traction conditions

For a heavy-haul locomotive within a wheel repairing period, wheel polygonal wear with different operating mileages is obtained by field testing. The test results show that the maximum radial runout of the wheel can increase to 0.87 mm and accompany with the typical damage of wheel tread shelling. Taking the wheel polygons as input excitation...

Measurement, Assessment, Analysis and Improvement of Transition Zones in Railway Track

Transition zones in railway tracks are locations with considerable changes in the vertical stiffness of the track support, which can be found near bridges, culverts and tunnels. In such locations, the stiffness variation and the differential settlement of tracks (uneven settlement of the track on the embankment and of the engineering structure)...

Corrective countermeasure for track transition zones in railways: Adjustable fastener

Transition zones in railway tracks are the locations with considerable variation in the vertical stiffness of supporting structures. Typically, they are located near engineering structures, such as bridges, culverts, tunnels and level crossings. In such locations, the variation of the vertical stiffness and the differential track settlement...

Modelling of the long-term behaviour of transition zones: Prediction of track settlement

Transition zones in railway tracks are the locations with considerable changes in the vertical support structures. Typically, they are located near engineering structures, such as bridges, culverts, tunnels and level crossings. In such locations, the variation of the vertical stiffness and the differential settlement of the track (when the...

Structural health monitoring of railway transition zones using satellite radar data

Transition zones in railway tracks are locationswith considerable changes in the rail-supporting structure. Typically, they are located near engineering structures, such as bridges, culverts and tunnels. In such locations, severe differential settlements often occur due to the different material properties and structure behavior. Without...

Analysis of Bridge Transition Zones in Railways Considering the Moisture Condition of the Ballast and Subballast

Transition zones in railway tracks are the locations with considerable changes in vertical support structures, e.g., near bridges. Due to possible water flow constrictions in transition zone structures, there is frequently an increased moisture level in the ballast/subballast layers, which is a potential source of track degradation. This paper...

Experimental analysis of railway track settlement in transition zones

Transition zones in railway tracks are the locations with considerable changes in the vertical support structures. Due to the differential stiffness and settlement in the open track and the engineering structure resulting in the dynamic amplification of the wheel forces, track settlement is usually observed in the approaching zones. The...