Влияние верхнего граничного условия на гидротермическое поле земляного полотна железных дорог в районах вечной мерзлоты

Abstract

Purpose: Based on numerical model that takes into account the hydrothermal interrelation of soil humidity and temperature, to carry out numerical modeling of hydrothermal field of railway subgrade in the area of permafrost spread. To study the influence degree of global warming and temperature annual amplitude on hydrothermal field of subgrade. To determine the need for reasonable and economical engineering measures to ensure the stability of subgrade. Method: Calculation of hydrothermal bonding of railroad subgrade has been performed in COMSOL Multiphysics software with the use of partial differential equation (PDE) module with the methods of finite elements. Different values of the parameters of subgrade upper boundary temperature function are specified and the effect of these parameters on subgrade hydrothermal field is studied. Results: Based on measured data temperature function, the influence of global warming effect and temperature annual amplitude on subgrade hydrothermal field was determined. Change law and characteristics of temperature distribution, ice content and unfrozen water in railway subgrade in permafrost areas after hydrothermal field stabilization has been obtained. The periods of maxima and minima onset for temperature as well as for ice content and unfrozen water are given. Practical significance: The use of given numerical model allows to predict effectively the tendency of subgrade hydrothermal field change in permafrost areas under global warming influence. Based on the numerical calculation results, relevant technical recommendations are shown for elimination or reduction of engineering accidents caused by temperature changes in permafrost regions.