Modelling a temperature regime of a railway track structure and its comparison with the results of experimental measurements

Abstract

Following the completed experimental monitoring of the temperature regime of the construction of a subgrade structure on the experimental stand of the Departments Railway Engineering and Track Management and measurement of thermal conductivity coefficients λ of building materials used in construction of a subgrade structure, there are constructed mathematical models, which are designed to not only verify the temperatures obtained in individual structural components of subgrade structure of experimental stand, but also the possibility to use appropriate software to model temperature regime of other types of constructions of subgrade structures. The paper presents mathematical models for the typical winter periods, which have been recorded since the beginning of the experimental measurements conducted from 2003 to the end of the winter period of 2013 using the software SV-HEAT SVOFFICE SoilVision [1] and there are also comparisons presented in achieving the position of zero isotherm in the construction of a subgrade structure. At the end of this paper, some of the knowledge obtained from the mathematical modelling of the temperature regime of the construction of a subgrade structure and confrontations with the temperature regime of a monitored, real railway track are underlined.

Preliminary results and conclusions from mathematical modelling of thermal regime of railway track structure

“…The SoilVision software enables mathematical modelling of various combinations of material compositions of railway track structure after entering all the relevant input data. In this way, conditions for drawing up the relevant design nomograms for various types of subgrade structure or railway body types [1,[4][5][6] are created.…”

Experimental monitoring and numerical modeling of thermal regime of railway track structure - preliminary results and conclusions

“…The experimental measurements as well as the numerical modeling of the thermal regime of the rail track (subgrade) confirmed that the air frost index is not the only parameter that influences the depth of rail track freezing (Hodas Ižvolt 2014). In the design methodology of the determination of structural thickness of the protective layer it is also necessary to consider…”

Freezing of the Subballast Layers of the Railway Formation – High Embankment and Double Track

“…The material of layer used for the numerical model experiment is identical with the material of our "in-situ" models at the Railway Engineering Department, by authors [2] in 2014 and in the world [3], [4] and [5]. The material and technical characteristics of these structural layers R i , which are applied to the MODEL 4, are shown in Tab.1, where: λ -thermal conductivity, ρ -bulk density, c -specific thermal capacity and w -volume content of water.…”

“…Numerical MODEL 4 represents the winter climatic load in the Poprad area (High Tatras Mountain Range) and the numerical MODEL 5 is increased by 30 % in the freezing effect of MODEL 4. The research was published in 2014 by authors [11], [2] and their climatic loads by the mean daily temperatures T s are shown in Fig. 1.…”