The article analyzes the condition of water-saturated earth slopes of structures under conditions of fluctuating water levels in reservoirs. A criterion has been substantiated for the necessity of considering hydrodynamic forces arising from unsteady seepage flow in water-saturated earth slopes during water level drawdown in reservoirs with different intensities. The relationship has been obtained for determining the phreatic surface within homogeneous water-saturated slopes at any moment during reservoir emptying, where groundwater flow occurs from infinity on the side of the soil mass. Regularities in the dynamics of the phreatic surface in water-saturated earth slopes during water level drawdown in reservoirs have been established for two types of foundations differing in permeability. Based on the research results, graphical relationships describing the dynamics of the phreatic surface in water-saturated slopes during water level drawdown in reservoirs have been constructed for homogeneous earth structures with a trapezoidal cross-section located on low-permeability and permeable foundations. It has been established that under certain construction and operation conditions of earth structures, the phreatic surface significantly lags behind the decrease in the reservoir water level. In addition, the study shows that the rate of decline of the phreatic surface along the slope height varies, which may significantly affect the intensity of reservoir drawdown
Kuzlo et al. (Tue,) studied this question.