Comparison of three-dimensional and two-dimensional axisymmetric finite element analyses of a corner section of a tailings dam

This paper presents three-dimensional (3D) and two-dimensional (2D) axisymmetric finite element analyses of a corner of a tailings dam. The analyses were performed to: (i) locate tension and/or low-compression zones and evaluate slope stability during sequential raising of the dam corner, and (ii) find whether the results of 2D axisymmetric analyses could be reliable for the dam corner. The corner is a potentially weak section of the dam, where tension and/or low-compression zones may develop. Development of such zones inside the dam corner can lead to cracks and initiation of internal erosion. The results of both the 3D and 2D axisymmetric analyses indicated that (i) tension and/or lowcompression zones were located in vicinity of surface of the dam corner mainly above the phreatic level, and (ii) the dam corner was stable up to the planned height if it was gradually strengthened with rockfill berms on the downstream side. The results of 2D axisymmetric analyses showed a fairly good agreement with those of 3D analyses. It is concluded that 2D axisymmetric analyses are appropriate for this dam corner. This implies that significant computational time can be saved by utilizing 2D analyses instead of 3D analyses.