Analysis of the results of field and computational studies of the strength and stability of the stone-fill dam of the Boguchanskaya Hydroelectric Power Station, predicting its condition

The results of complex field and computational studies of the strength and stability of the stone-fill dam of the Boguchanskaya HPP are presented. The purpose of the work is a comprehensive assessment of the state of the stone-fill dam of the Boguchanskaya HPP, including forecasting its condition. An analysis of the data of field observations was carried out, which showed a number of differences from the design prerequisites. Analysis of the data on precipitation and horizontal displacements of the marks installed on the berms of the lower thrust prism of the SFD of the Boguchanskaya HPP showed that they are not extinguished. On the basis of the developed and calibrated spatial permanent finite element model, comprehensive computational studies of the stress-strain state of the stone-fill dam of the Boguchanskaya HPP were carried out (including the sections in which the highest precipitation and horizontal displacements of the marks installed on the berms of the lower thrust prism of the stone-fill dam were recorded), taking into account the data of field observations, including deviations from the project. Calculations showed that with the actual profile of the stone-fill dam of the Boguchanskaya HPP, slightly less than in the project, the value of the stability factor of the lower slope was 1.32‑1.33, which exceeds the standard value of 1.25. At the stage of forecasting the state of the stone-fill dam of the Boguchanskaya HPP for the period up to 2040, the estimated value of the stability factor of the lower slope may be 1.25, which is equal to standard value (i.e. the margin is minimal). At present, the stability of the lower slope of the stone-fill dam is ensured, despite the deviations of the actual dimensions of the profile of the stone-fill dam from the design values. With further growth of sediment, as well as horizontal displacements of marks installed on the berms of the lower thrust prism, the stability of the lower slope of the stone-fill dam may change.

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