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

Abstract

The paper characterizes the existing results and preliminary conclusions of mathematical modelling of the thermal regime of railway track structure carried out on the experimental stand and optimizes the structural thickness of the protective layer in the subgrade structure by the SVHEAT SoilVision software. SoilVision system is a modelling software based on the finite element method developed for geotechnical engineers. The first part describes the experimental stand design and methodology for monitoring the heat and humidity variations in the railway track structure [1]. This paper section characterizes the results of mathematical modelling of the thermal regime of the railway track model and subsequently carries out a comparison of results of experimental measurements and mathematical modelling by the SVHEAT [2]. The paper enables mathematical modelling of various combinations of material compositions of railway track structure after entering all the relevant input data of the winter periods. In this way, conditions for drawing up the relevant design nomograms for various types of subgrade structure or railway body types are created.

Modelling of Railway Track Temperature Regime with Real Heat-Technical Values for Different Climatic Characteristics

“…The main task of the research was to find the maximum depth of freezing, i.e. the position of the zero isotherm, not only check of the individual measurements on positions during the analysis (eventually comparison with the temperature values from points of practical measurements "in-situ" on real models built by our department, [4]). …”

“…loaded by climatic temperatures of the period with the highest frost index during the reporting period from 2003 to 2017 [4], which is presented by the winter 2005/2006. MODEL 2 -climate from the period when the greatest depth h F of freezing construction layers was obtained and it was in winter 2011/2012 since 2003 [5].…”

Preliminary results and conclusions from the experimental monitoring of thermal regime of railway track structure

“…In the case of this experimental stand, there was also added the parameter of inbuilt material humidity. This parameter, which substantially influences the thermal regime of the rail track structure and also the depth of subgrade freezing, is necessary for mathematical modelling of the subgrade thermal regime using the SoilVision software (closely characterized in [7]). …”

“…The concept and design of the experimental stand was based on the long-term experience gained from the experimental measurements of the subgrade thermal regime at the experimental stand DRETM I. As at the time of construction of the experimental stand DRETM II the software for mathematical modelling of the subgrade thermal regime was available, besides higher number of thermal sensors, humidity sensors were also embedded to acquire one of the input parameters for mathematical modelling of the thermal regime using SoilVision software (see [7]). The experimental stand DRETM II represents the railway track model run on the embankment in the scale 1:1 -Figs.…”

Moddeling of Negative Ambient Air Temperature Effect to Frost Depth of Lithuania Railroads Construction

“…Straipsnis ar jo dalys negali būti naudojami komerciniams tikslams. Šaltojo periodo "ekstremalumas" GKK vertinamas pagal šalčio indekso dydį I m (Hodas et al 2016). GKK įšalimo gylis yra apibrėžiamas kaip 0 °C gylis nuo GKK paviršiaus.…”