Frost heaving of sandy clay soil depending on degree of its salinity with NaCl solution

Relevance. The paper considers the problem of frost heaving in zones of permafrost and seasonally thawed soils. This problem is very actual at designing, construction and operation of industrial and residential objects, as ground frost heave leads to increase of volume of soil base, in consequence of which buildings and constructions are exposed to serious deformations. In the area of human activity, the soil base is subjected to various thermal and baric influences combined with additional overwatering and salinisation due to anthropogenic destruction, construction works and other activities, as a result of which the risks of heaving are significantly increased for such soils. Aim. To study frost heaving and methods of its prevention on the example of artificial salinization of loamy soil by NaCI solution of different concentration depending on temperature. Methods. Laboratory studies of soil condition in natural conditions of occurrence: determination of moisture content by drying to constant mass, upper plasticity limit, lower plasticity limit, granulometric composition by sieve method, true density, skeleton density (dry) and porosity of soil and determination of actual degree of soil looseness. Results. Deep sampling of soil prone to frost swelling was carried out at the object: JSC Transneft-Siberia, Tobolskoe UMN, Demyanskoe LPDS, during the period from June to July 2022. Individual soil samples were grouped into series depending on the depth of sampling and physical and mechanical properties of the soil. The main soil samples were classified as tight loam light/heavy, dusty/sandy [5]. During laboratory studies the authors have obtained the dependences of parallel experiments at different salinity and frost temperatures of the soil to determine the degree of soil heaving. It was found that artificial salinization of soil samples, significantly reduces the degree of frost heaving of rock.