Abstract:
This study investigated the potential influence of operating water levels and loading
conditions on the slope stability of an embankment dam. Four different operating reservoir levels
(normal, reduced, embankment height, and overflow) were considered in the study. Numerical
modeling was used to investigate the problem in the case of the Chardara dam within the Syrdarya
catchment in Kazakhstan. Based on the drawdown rates and operating conditions, minimum
factor of safety values ranging from 0.56 (total failure) to 2.5 were retrieved. Furthermore, a very
high correlation was observed between drawdown days, the minimum factor of safety values, the
maximum factor of safety values, and pore-water pressures, with correlation coefficients ranging
from 0.561 to 0.997 (strong to very strong correlation). On the other hand, the highest negative
correlation of 0.997 was observed between the minimum factor of safety values and pore-water
pressures. Additionally, based on the results from the analysis of variance, three reservoir operating
levels (normal, embankment height, and overflow) resulted in p-values less than 0.05, indicating that
the variations in the factor of safety values from the drawdown rates were statistically significant.
The findings of this study demonstrated that, not only may the drawdown rate be detrimental to the
embankments, but that different operating levels can also affect slope stability in different ways.
