Review of the Modern Ballasted Railway Tracks’ Substructure and Further Investigations

Abstract

Purpose. The authors' aim is to summarize the results of relevant international publications and, based on these, to give a comprehensive review about the modern ballasted tracks' substructure. Methodology. This article is a start of a PhD research, which means it was proceeded by a secondary research. At first, the substructure and its protection layers were summarized, after that the geosynthetic cementious composite mat materials, especially the Concrete Canvas are discussed. Findings. The experiences of the geosynthetics' and other protection layers' functions, show that a possible using of the GCCM (geosynthetic cementious composite mat) under the ballast can be a good solution for renewing short sections in the railway tracks. Originality. One of the authors-namely Balázs Elleris a PhD student at Szechenyi Istvan University in Gyor (Hungary). His research topic is the reinforcement possibilities of railway substructure with the usage of special (mainly cement-bonded) layers. This article was written to collect and summarize the up to date knowledge related to modern ballasted railway tracks' substructure to be able to determine the following research ways and possibilities at this topic. The research plan will be sentenced in the near future, as well as the required laboratory and field tests will be prepared. Practical value. As expectation, after having executed the related research, the advantages and disadvantages of GCCM layers in the railway substructure will be able to defined, as well as factual deterioration process can be determined related to the ballasted tracks and their geometrical stability.

Tutorial on the emergence of local substructure failures in the railway track structure and their renewal with existing and new methodologies

“…The dynamically emerging traffic load is a repeating, cyclic type of load. The effects of the static and dynamic loads differ on the lower layers, even if the axle load is the same [8,9].…”

“…It is made up of natural and / or artificial materials. The applied technology must be determined depending on the needed functions to be performed and the technical parameters of the used materials [9].…”

“…The low dead weight and easy machinability make it suitable for use to protect the railway substructure. Experiences have shown that by modifying the screening machine during the renewing, the sandy gravel layers can be neglected, but damage can happen while laying [9]. It has been used in a few places in Hungary so far (railway line 40. between Szentlőrinc and Pécs; Budapest tramway line 1), but the experiences were adequate [2].…”

Mathematical Support of Machine Surfacing for the Railway Track

“…Correct execution of surfacing allows not only to restore the track geometry in the vertical plane but also to provide the necessary ballast consolidation. The condition of the ballast layer is one of the main factors determining the (structural and geometrical) stability of the track as a whole [10] and the timing of the next repairs [11]. Among other things, high-quality ballast consolidation during surfacing provides uniform track elasticity, which affects the dynamic performances of the track and rolling stock interaction [12].…”

Research of the Reduced Mass of the Railway Track

“…Many developments, most of which use the latest scientific approaches, are devoted to this study of the stress-strain work of the under sleeper base. So, for example, work [7] makes the analysis of a modern condition of such researches. More often it is the finite element method (FEM) [8,9], in addition, it is the method of discrete elements [10], computed tomography [11], the process of elastic waves propagation [12,13], and others.…”