Analysis of seepage through an earth dam with a diaphragm on an impermeable foundation using PLAXIS 2D

Introduction. In the current climate change conditions, the protection of irrigation structures, especially dams, is a very important task. Seepage is one of the main causes of dam failure, so it is very important to investigate the seepage regimes and find solutions to prevent dam failures as a result of the seepage processes in earth dams. In this paper, the analysis of the seepage regimes in the body of earth dams is performed by means of mathematical modelling using numerical finite element models. A homogeneous earth dam with an imperfect diaphragm on an impermeable foundation is taken as the object of study. The purpose of the study is to determine the influence of relative parameters: diaphragm height, diaphragm location in the dam body, their number. In addition, the influence of diaphragm parameters on the seepage flow through the dam body and its velocity is analyzed.Materials and methods. The study was carried out with the help of numerical modelling using PLAXIS 2D software. The model of the dam is based on typical design solutions used in practice.Results. The results of the study show that the placement of the diaphragm in the dam body reduces the seepage flow through the dam and the height of the diaphragm is inversely proportional to the seepage rate. The maximum seepage rate was recorded at the upper end of the diaphragm and its magnitude is directly proportional to the height of the diaphragm. When the diaphragm is displaced towards the downstream side, the filtration rate slightly decreases. The value of maximum velocity increases when the diaphragm is displaced towards the downstream end.Conclusions. Dam failure due to seepage can result in serious property damage and loss of life. Implementing methods that reduce seepage discharge and seepage velocities is important to ensure safe dam operating conditions