ANALYSIS OF THE DEGREE OF INFLUENCE OF INTERNAL AND EXTERNAL FACTORS ON THE TEMPERATURE REGIME OF A LOW-CEMENT CONCRETE DAM

Abstract

In this paper, we consider the issue of assessing the degree of influence of the selected factors on the temperature regime and the thermally stressed state of a concrete gravity dam being built from low-cement concrete for several possible construction scenarios. The studies were carried out in relation to the design and conditions of the construction area of ​​the Pskem hydroelectric complex in the Republic of Uzbekistan. Variation factors were: cement consumption in the mixture, the initial temperature of the concrete mixture, the heat release of cement, the thickness of the laid concrete layer, the month of commencement of work. The environmental factors were the variable ambient temperature during the year by months and the influence of solar radiation. The calculations were carried out taking into account the seasonality of the moment the construction of the structure began. 2 options were considered: autumn-winter with concreting of the zone at the base of the dam from September to February inclusive; spring-summer with concreting of this zone from March to August inclusive. In addition, options were considered taking into account additional heating from exposure to solar radiation and without it. The studies were carried out using the methodology of experiment planning in the search for optimal solutions (method of factor analysis). The numerical experiment was carried out on the basis of the finite element method using the ANSYS software package. Using the method of factor analysis, the influence of the main acting factors on the temperature regime of a gravity dam made of rolled concrete was studied. A variant of a combination of factors is proposed to obtain the most favorable temperature regime. Regression equations are obtained for predicting the temperature regime of concrete gravity dams being built from low-cement content concrete. The results of studies using the factor analysis technique can be used in the design of concrete dams from rolled concrete.