Investigation of railroad ballast particle breakage

Abstract

This paper summarizes the authors' up-to-date results in the research topic of railway ballast particles' breakage test with individual laboratory test. In the past few years there were a lot of railway rehabilitation and maintenance project in Hungary, as well as abroad. The largest part of world's railways has traditional superstructure, i.e. they are so called ballasted tracks. The railway ballast is the highest mass in the railways' superstructure. Nowadays, it is a naturally fact that there is enough quantity of railway ballast in adequate quality. However, due to the modifications and restrictions in the related regulations since 2010, there are only few quarries in Hungary, which are able to ensure adequate railway ballast material for railway construction and maintenance projects for speed values between 120 and 160 km/h. Quarrying industry is stricken by aggravated environmental, heritage and conservation regulations year by year, it limits the accessibility of mineral wealth in significant manner. This fact with quality requirements means supply and quality risk in production of railway ballast in medium term. The main goal of authors' research is to be able to simulate the stress-strain effect of ballast particles in real and objective manner in laboratory circumstances, as well as in discrete element method modeling. This paper introduces the exact assembly of executed laboratory test and newest test results. The authors summarize the up-to-date international literature review, using that they give short outlook to the planned research with research directions in near future.

Effect of rock strength on the degradation of ballast equipped with under sleeper pad using discrete element method

“…This leads to enhanced fatigue and degradation of tracks [3], particularly in stiffer subgrades such as crossings and bridges [4,5]. Elevated stresses in the granular layer further amplify the deterioration of the track over time [6], leading to excessive vertical and horizontal deformations [7], fragmentation of the ballast [8], accumulation of debris in the ballast, and obstruction of drainage [9]. A multitude of field and laboratory tests have been carried out to examine the effects of Under Sleeper Pads (USPs), with the majority of them indicating favorable results.…”

Determining the Deformation Characteristics of Railway Ballast by Mathematical Modeling of Elastic Wave Propagation

“…Experimental studies have investigated the effects of particle destruction, clay and diesel pollutant infiltration, and the impact of moving trains on the ballast state in papers such as [2][3][4][5][6][7][8][9]. The impact of moving trains becomes particularly relevant when transporting bulk cargoes such as coal and grain [9], as well as with high values of axle loads [10,11].…”

Investigation of the Glued Insulated Rail Joints Applied to CWR Tracks

“…In relation to the above-mentioned technologies and technical solutions, we can mention some special ones such as application of noise and vibration damping layers and elements [2][3][4][5][6]; ensuring lower stress in the railway permanent ways' that result and ensure lower elastic and plastic deformation in the track as well as in the layer structure [7][8]; techniques which provide special work processes, e.g. tamping of wide sleepers or side tamping that does not disturb the dense, compacted sub-ballast layer [9][10]; new and newer technologies ensuring decreased dynamic effects that can result in subsidiary failures (maybe cracking, fracturing, breaking) in the tracks' elements [11]; minimizing the wear of track elements (mainly the rails') [12] and lowering the ballast breakage [13][14][15][16]. The determination of the geometrical deterioration process is also quite important [17][18] for the ability to predict maintenance work.…”