MODELING THE SLOPE STABILITY ON THE LOW-HEAD DAM OF THE OKTYABRSKY RESERVOIR DURING CLIMATIC CHANGES IN THE HYDROLOGICAL REGIME

Purpose: modeling the slope stability of a low-head dam using the finite element method based on the example of the long-operated Oktyabrsky Reservoir. Materials and methods. The main attention is paid to studying the impact of the hydrological regime on strength and durability of the low-head dam structure. Sharp alternation of wet and dry periods creates additional stress in the body of the low-head earth dam of the Oktyabrsky Reservoir. The research methodology is based on a combination of finite element modeling and field studies. SCAD Office, which is a set of applications for computer-aided design and finite element modeling, was used. Calculations of the dam slope strength were performed, taking into account the dynamic water pressure, filtration processes and mechanical deformations. Additionally, an assessment of the durability of the structure was carried out in changing hydrological regime, including water level fluctuations, flood duration and various periods of low flow rates. Results. An integrated approach to modeling the slope stability of a low-head dam under real hydrological changes is proposed. The proposed methods and models are universal and can be used for similar structures in other regions. Radiograms of landslide processes that occurred as a result of accidents and were eliminated during the reconstruction of the dam, were obtained. Conclusions. The conducted studies are devoted to assessing the technical condition of the earth low-head dam of the Oktyabrsky Reservoir using engineering and geophysical methods. Finite element modeling was performed based on the obtained data on failures. The maximum dimensions of landslide development that are dangerous for the operation of a low-head dam are established, when a landslide occupies more than 17 % of the dam body in the transverse profile and more than 22 % in the longitudinal profile. Local zones of active development of landslide processes caused by long-term operation, heterogeneity of the soil foundation and the impact of external factors are revealed.