DOI: 10.7256/2453-8922.2017.4.25027

Abstract: This article concentrates on the experimental research of the heat and mass transfer properties of the technogenic soil of Yakutia that are subject to freeze-thaw cycles. Definition is given to the technogenic soils according to the GOST 25100-95. The work cites the established fact of significant difference in the coefficient of filtration of naturally located soils of seasonal layer of thaw from indexes acquired in controlled conditions. It is substantiated that there is a need to research the heat and mass transfer properties of the technogenic soils with consideration of the cyclic impact of the low temperatures and changes in the cryogenic structure for a more complete correspondence with the northern conditions. The authors analyze  the acquired data, approximate the experimental data via the methods of statistical processing and compare it with the data from other sources. The conducted research allowed determining the dependence of the thermophysical properties of the technogenic soils upon their moisture, temperature and loam content.

DOI: 10.7256/2453-8922.2017.4.25035

Abstract: This article focuses on the experimental research of the impact of additives of surface active agents upon the strength of the frozen dispersed soils. The work touches on the problem of finding new theoretical approaches towards mechanical properties of dispersed soils accounting for presence of free surface energy and impact of the physical chemistry factors upon the behavior and properties of the soils. Substantiation is made on the physical chemistry approach as the most promising one in this area. Pyotr Rebinder’s mechanism for strengthening thawed soils through the effects of the surface active agents is presented in this research. Experimental research was conducted on the strength characteristics of the frozen dispersed soils with use of surfactants and without additives. The conducted research yielded experimental curve relationship of the maximal strength from time for frozen sand and loam with surfactants and without.

DOI: 10.7256/2453-8922.2017.4.25036

Abstract: This article examines the issue of numerical modeling of the soil freezing-thaw process for projection of thermal stabilization system of soil building foundations in the cryolithozone of the Sakha Republic (Yakutia). The goal of this work consists in studying the process of formation of the temperature field of the massif of the soils under the effect of thermal stabilizers. Research is conducted on the process of formation of ice wall as the result of thermal exchange of the soil with the thermal stabilizers and external cool air during clearing of the snow cover from the construction site. The main conclusions of the conducted research include the need for development of mathematical models that would account for the mass exchange processes in the zones of effect of the thermal stabilizers with consideration of the conditions of formation of the cryogenic textures in the process of forced freezing of the soils. There is also a need for mathematical explanation of the phenomena of condensation and evaporation of Freon taking place inside the thermal stabilizers.

DOI: 10.7256/2453-8922.2017.4.25037

Abstract: The subject of this research is the interaction of the seasonal thermal stabilizers with the soils, processes of thermal and mass transfer and formation of cryotextures. The thermal stabilizers found broad implementation in northern construction for strengthening foundations of buildings formed with plastic and thawed dispersed soils with installation of Anti-filtration screens and ice walls. The efficiency of the work of thermal stabilizers is assessed based on the rate of formation of the calculated temperature schedule in foundations of engineering structures. The presented data of formation of temperatures of the soil foundations cooled by the liquid-vapor thermal stabilizers reflect regularities characteristic for dispersed soils of all types with various indexes of moisture and salinization for buildings with ventilated crawl spaces.