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

Abstract

High quality of railway track construction is a major priority. One of the quality elements is the resistance to load of railway formation with individual structural layers caused by negative temperatures during the critical freezing period of winter. Numerical modelling allows obtaining more control outputs at different climatic loads. The presented paper shows the load of railway track model with different variants of climate and shows the importance in the designing of the non-transport load under negative temperatures, i.e. observation of transition of the zero isotherm through the layers of railway subgrade. If the subgrade layers of the railway formation are built with high quality and durability then the axis of the track will keep its geometric spatial position during the long-time operation.

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

“…The model was loaded during 120 days in the winter period from 10 November (year) to 10 March (year + 1). In the study, 5 model climatic loads were solved: MODEL 1 (I f120 = -252 °C), MODEL 2 (I f120 = -150 °C), MODEL 3 (I f120 = -375 °C), MODEL 4 (I f120 =-600 °C) and finally extreme winter MODEL 5 (I f120 = -800 °C), [10] in 2017. MODEL 1 and MODEL 2 are also built in the "in-situ" area of the KZSTH laboratory.…”

Experimental determination of indicators of thermal state of refrigerator cars under operating conditions

“…In [3], the results of analysis of heat exchange processes occurring in refrigerated rolling stock (RRS) under operating conditions are presented, and also methods of thermal tests of cars are considered. It is proposed to estimate the thermal properties of individual body sheathing structures on the basis of determining heat transfer coefficients in local zones, which allows identifying defects in the body insulation, during construction and repair of cars.…”

“…All this suggests that as the car life increases, the error of evaluating the thermal properties will increase. This is the main disadvantage [3] of the work.…”

“…where W ne is the power of heating devices, W; p is the absolute air pressure, Pa; v is the volume of cargo space, m 3 ; m is the mass of air in the cargo space of the RC body at the beginning of heating, kg; m f is the mass of air losses through the filtration openings during heating, kg; Q f is the heat flow of air filtration, W; b) equation of heat flow through the body sheathing due to conductive heat transfer…”

Contribution to the Modification of Input Data of Subgrade Structure Dimensioning for Non-Traffic Load According to the Žsr Methodology

“…The numerical modeling was conducted parallelly with monitoring of the thermal and water regime of the experimental model and its subgrade. Using the software support (SV-HEAT SoilVision) [4], it was possible to numerically model the respective winter period the structure was exposed to and subsequently compare the achieved values of its freezing with the values reached at the real structure -measuring profile of the experimental stand [5]- [7].…”