Determining the temperature of soil under a building with a ventilated basement

This work is aimed at computational comparative studies of natural changes in soil temperature and under a building with a ventilated basement in Norilsk. In contrast to conventional projects, it was planned to locate a small part of the building directly on the ground, which could lead to additional thawing of the soil. Laboratory data on soil samples in the thawed and frozen state, taken from boreholes at the construction site, and the results of soil temperature measurements at a depth of about 14 m were used to perform calculations. When forming the boundary conditions of the calculation model on the outer surface of the soil, the radiation balance for the conditions of Norilsk was considered. It was found that the radiation balance from May to August is positive and leads to soil heating, and in the rest, most part of the year, it is negative and causes soil cooling. New results obtained demonstrate that a decrease in the moisture content of the surface soil layers reduces the influence of phase transitions on the thermal-inertial properties of the soil, which leads to an increase in the thickness of the active soil layer (where annual temperature fluctuations are observed), an increase in the depth of thawing in the summer-autumn period, and a decrease in the soil temperature under the active layer. The temperature distributions over the depth of soil under different sections of the building with a ventilated basement and in the immediate vicinity of the building in a long-term operation cycle after completion of its construction were calculated. According to calculation results, the maximum depth of soil thaw under a building with a ventilated basement decreased by 12% compared to natural conditions, reaching 1.1 m. It is shown that for multi-story buildings with ventilated basements, individual structural elements with insulation can be located directly on the ground surface, and additional thawing of the soil will not occur under them. However, for this case, the absence of additional thawing of soil should be confirmed by a heat engineering calculation taking into account the ratio of surface areas of the ventilated basement and the structural elements located on the ground, as well as the features of their insulation.