Abstract
This paper presents a calculation of the mass transfer of water and its accumulation in the soils of the base of the road, considering the engineering-geological zoning on the example of the city of Astana, Kazakhstan. A detailed analysis of the physical and mechanical properties of the foundation soils of the highway in the geoclimatic conditions of the city of Astana was carried out. The temperature fluctuations of the layers of the pavement and the base of the subgrade in the winter period were monitored by installing sensors in the layers of pavement and subgrade of the road. The depth of freezing in winter was determined, and the distribution of temperature in the depth of the pavement and base soils was analyzed. It has been established that the soil foundations of roads, as well as the layers of pavement, remain in a stably frozen state due to sub compensation of heat transfer of the underlying layers and have a sufficient margin of safety. It was determined that the mass transfer of water in gaseous state was 1.44 10 –4 g/h per 1 dm³ of soil volume at a temperature of -5-8 °C at a depth of -60 cm under the road. To prevent negative impact and uneven deformation of the subgrade in zones 1-8 in Astana city, it was recommended to provide additional vapour barrier at a depth of 57-60 cm, before the construction of the underlying layer of gravel-sand mixture.