Исследование распределения порового давления под подземной плотиной в горной долине при аккумулировании атмосферных осадков

Abstract

Purpose: to study the distribution of pore pressure under an underground dam located in a mountain valley for the atmospheric precipitation accumulation, while analyzing the effect of water levels in headwater and tailwater. At the same time, the factors of influence varied in the range: the water level in headwater from minus 8.2 to minus 1.2; water level in tailwater from minus 7.9 to minus 6.7. Materials and methods. The study of a complex system was carried out in two stages. At the first stage, the pore pressure under the underground dam, responsible for the seepage under it, was calculated using the finite element method based on the Midas GTX NX software package, which has the ability to take into account the complex joint operation of the underground dam and the soil mass. At the second stage, the resulting array of numbers, which reflects the physical processes occuring when the response function, which is taken as the pore pressure under the underground dam, is affected by disturbances, for which the water levels in headwater and tailwater of the dam are taken, was subjected to digital analysis. Results. The range of pore pressure values at the maximum headwater levels is 31.72 % over the entire range of tailwater levels. For the average levels of the headwater, the range of pore pressure values is 32.70 %, and for the minimum levels of the headwater, the range of pore pressure values is 39.41 %, also in the entire range of changes at the tailwater levels. Thus, the lower the headwater level, the greater the impact on the pore pressure of the tailwater level. Conclusions: with a change in the studied range of water levels in headwater or tailwater of the dam, i.e. factors of influence, with a decrease in the values of the impact factors, the degree of their influence on the pore pressure under the underground dam decreases, and with growth – increases, and it occurs almost linear.