Stability analysis on a fossil fuel ash dam using a 3D numerical method

South Africa will be producing power using Fossil fuel power stations for the foreseeable future. Large volumes of ash are produced during this process, which is disposed using wet or dry systems. Optimizing these dumps will reduce the power station’s environmental impact and costs due to the reduction of land area required and additional lining and infrastructure costs. As the processing power of computers increase, more complex numerical and mathematical simulations are possible. This study will use numerical modelling software, FLAC3D, to assess the slope stability of an ash dam. This model is then compared with the more conventional and sufficient Morgenstern-Price method using Slope/W. Some of the major disadvantages of most conventional 2D models is that the effect of irregular shapes is not taken into consideration and that selecting of a most vulnerable section is subjective. 2D models are also more conservative than 3D models. During this study a factor of safety of 1.5 is maintained as a stable slope and the effect of earthquakes is not evaluated due to South Africa’s location in respect to fault lines