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 . 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 . 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.
mathematical modelling of thermal regime, railway subgrade, railway track, SVHEAT Soil- Vision
 Ižvol, L., Dobeš, P. & Pitoňák, M., Preliminary results and conclusions from the experimental monitoring of thermal regime of railway track structure. Proceedings of the COMPRAIL 2016 - 15th International Conference on Railway Engineering Design & Operation, WESSEX Institute of Technology: Madrid, Spain, http://www.wessex. ac.uk, WitPress, http://www.witpress.com, Southampton, United Kingdom, 2016.
 SVHEAT 2D/3D Geothermal Modelling, SVOFFICE 2009 - Geotechnical Modelling Suite, SoilVision systems Ltd., http://www.soilvision.com, Saskatoon, Saskatchenwan, Canada, 2016.
 VEGA 1/0756/12 Experimental monitoring and mathematical modelling of thermal regime of railway subgrade structure. Scientific Research of Dept. of Railway Engineering, Fac. of Civil Engineering, University of Žilina, Žilina, http://svf.uniza.sk/kzsth. VEGA - Ministry of Education, Science & Research of the Slovak Republic, http://www.minedu.sk, Bratislava, SK, 2012–2015.
 Ižvolt, L., Dobeš, P. & Pitoňák, M., Some experience and preliminary conclusions from the experimental monitoring of the temperature regime of subgrade structure. Proc. of the COMPRAIL XIV Computer in Railways - Railway Engineering Design and Optimization, WITpress, http://www.witpress.com, WIT transactions on the built environment, 135, pp. 267–278, 2014. http://dx.doi.org/10.2495/CR140211
 Hodas, S. & Ižvolt, L., Modelling of temperature regime of railway track structure and its comparison with the results of experimental measurements. Proc. of the COMPRAIL XIV Computer in Railways - Railway Engineering Design and Optimization, Rome, Italy, WESSEX Institute of Technology, http://www.wessex.ac.uk WitPress, 135, http://www.witpress.com Southampton, United Kingdom, pp. 253–265, 2014. http://dx.doi.org/10.2495/CR1402014
 Hodas, S., Design of railway track for speed and high-speed railways. Proc. of the XXIII Russian - Slovak - Polish Seminar, Theoretical Foundation of Civil Engineering, Procedia Engineering, 91, online http://www.sciencedirect.com/ science/article/pii/S1877705814030744#, pp. 256–261, 2014. http://dx.doi.org/10.1016/j.proeng.2014.12.056.
 VEGA 1/0275/16 Design optimization of sleeper subgrade due to non-traffic load aspect. Scientific Research of Dept. of Railway Engineering, Fac. of Civil Engineering, University of Žilina, Žilina, http://svf.uniza.sk/kzsth VEGA - Ministry of Education, Science & Research of the Slovak Republic, http://www.minedu.sk Bratislava, SK, 2016–2019.