Stability Analysis of a Coal Combustion Residuals Impoundment

The overall stability of the Rovinari dry ash slurry impoundment is analyzed using a coupled seepage-stability analysis with the Finite Element Method in a bidimensional model. To better understand the behavior of such a complex structure, based on the material properties presented in Table 2, the hypotheses presented in Table 4 and described as such, a number of 9 general hypotheses were analyzed, at 178.00 m a.s.l. deposit elevation and final designed height of approximately 35.30 m which corresponds to 191.3 m a.s.l.. The results are presented in tabular form, only 8 diagrams are selected which show the Factor of Safety for hypothesis 0 and 3 which are considered to best describe the real-life conditions regarding the boundary conditions used. The results show that even at maximum designed height, the deposit is stable in the most realistic worst-case hypothesis 3, with a Factor of Safety of 1.177.