A New High-Efficiency Procedure for Aggregate Gradation Determination of the Railway Ballast by Means Image Recognition Method

Abstract

The mechanical characteristics of the railway superstructure are related to the properties of the ballast, and especially to the particle size distribution of its grains. Under the constant stress-strain of carriages, the ballast can deteriorate over time, and consequently it should properly be monitored for safety reasons. The equipment which currently monitors the railway superstructure (like the Italian diagnostic train Archimede) do not make any “quantitative” evaluation of the ballast. The aim of this paper is therefore to propose a new methodology for extracting railway ballast particle size distribution by means of the image processing technique. The procedure has been tested on a regularly operating Italian railway line and the results have been compared with those obtained from laboratory experiments, thus assessing how effective is the methodology which could potentially be implemented also in diagnostic trains in the near future.

Full-Scale Field Experimental Investigation on the Intended Irregularity of CWR Track in Vertical Plane

“…The track becomes deformed, caused by the diversification of the track support characteristics in its various cross-sections. The diversification results in turn from an uneven settlement of the ballast during operation [7] and increases deformations, especially the so-called weak subgrade, or the occurrence of swelling soil in the subgrade. As a result of these irregularities, various forms of contact between the sleeper and the breakstone ballast layer are created.…”