Analysis of the subgrade design concept in areas of permafrost soil distribution in Western Siberia

Abstract

The subgrade design concept on permafrost soils was developed in the last century, and currently it are still used in the highway engineering by design organizations. However, this design concept doesn't provide the required stability of the subgrade that leads to premature destruction of road pavement. One of the main reasons for the destruction of road pavement is the lack of accounting for the processes of heat and moisture transfer of the "atmosphere — embankment — active base layer" system. When filling the subgrade with loosely frozen soils and dry frozen soils, the estimated embankment height according to the first principle is 2,0–2,5 m. Nevertheless, in summer the embankment soils, but also the active base layer is thawed by filtering water. This leads to additional waterlogging of the active layer and the occurrence of deformations of the settlement of the subgrade and road pavement. In winter the water potential thus accumulated migrates to the freezing zone, and due to the forces of frost heaving, expansion and cracking de-formations of the embankment soils appear. Therefore, the development of structures using geotechnical materials is necessary for reliable regulation of the water-thermal regime of the embankment.