Laboratory Evaluation of Railway Ballast Consolidation by the Non-Destructive Testing

Abstract

The property of railway track to resist the irreversible deformation for a long-term operational loading considerably depends on the ballast layer. The ballast layer is the element of a railway track whose mechanical properties and state are formed in-situ with the help of the ballast cleaning, tamping and distributing machines. The varied properties of the ballast material to obtain the form during the maintenance and retain it during the operation are equally important for the ballast layer. The control over the processes of the ballast consolidation and deconsolidation by means of measurement methods could potentially provide great possibilities for improvement of its properties both during the maintenance and operation. The paper deals with an experimental study of the railway ballast consolidation and deconsolidation processes under the vibration loading of the sleeper. A non-destructive measurement method is proposed to investigate the distribution of the ballast consolidation along the sleeper. The method is based on the measurement of time of mechanical wave propagation. Modern low-cost sensors and powerful microcontroller techniques enable creating smart measurement systems for automatic multi-point data acquisition, online processing and statistical estimation of the ballast consolidation distribution.

Devising a procedure for assessing the subgrade compaction degree based on the propagation rate of elastic waves

“…Work [24] reports the development and application of a method for determining the compaction of the ballast layer. The experimental study revealed a significant change in the properties of ballast in the process of its deformation under the sleeper.…”

Determining patterns in the stressed­deformed state of the railroad track subgrade reinforced with tubular drains

“…Papers [18,19] proved that the increase in the dynamic action of moving transport units on the subgrade occurs due to the uneven subsidence of the ballast of the railroad track. It was also proved [20] that in order to ensure the smooth operation of the track, control over the condition of its lower structure, namely the subgrade under the action of dynamic loads from the rolling stock of railroads, is required.…”

“…Papers [4,[18][19][20][21][22] examine the processes of the subsidence of the ballast of the railroad track under the action of static and dynamic loads without taking into consideration the technical condition of the subgrade. In addition, none of these papers resolved the issue of increasing the carrying capacity of a heterogeneous subgrade, which is of great importance in the operation of the railroad track.…”

Experimental and Theoretical Evaluation of Side Tamping Method for Ballasted Railway Track Maintenance

“…A method for prediction of track quality deterioration is proposed, which takes into account maintenance works, subgrade stiffness superstructure, and operational properties. Laboratory and in-situ estimation of ballast compaction with non-destructive testing methods is presented in other studies [28][29][30]. The presented methods are based on the kinematic and dynamic interpretation of wave propagation in ballast layer.…”

“…The presented methods are based on the kinematic and dynamic interpretation of wave propagation in ballast layer. The studies by Sysyn M. et al and Sysyn M. et al [30,31] allow to determine the differences in ballast compaction along the sleeper after vibration loading. Numerical simulation of ballast compaction and ballast porosity using discrete element method is shown in other papers [32][33][34][35].…”