NUMERICAL ASSESSMENT OF PERMAFROST DEGRADATION AND RECOVERY AND ITS IMPACT ON SOIL MASS STABILITY

The paper presents solutions of the unsteady temperature problem and the problem of determining the stress-strain state of the soil massif, which is a bulk construction of stacks used for gold extraction from ore by heap cyanide leaching. In the process of irrigation of the stacks with heated cyanide solution occurs, heating of the soil mass and base, which leads to the formation of a zone of thawed permafrost or the so-called talik. As a result of numerical solution of the non-stationary temperature problem taking into account the step-by-step erection of the soil massif, the impact of air temperature and irrigation solution, the temperature distribution in the massif and the base for the period from the beginning of the massif erection to the 50-year period after the end of construction was obtained. For the most dangerous moment of the end of construction, when the zone of ground thawing is maximum, the stability of the slope together with the base is evaluated using their stress-strain state. The problems were solved by numerical finite element method using PLAXIS software package.