Seismic Behavior of Tailings Dam Using FLAC^3D

Failure of tailings earthen dams during earthquake is a common incident. Environmental hazards created by the release of stored tailings waste during the failure of such earthen dam must be addressed during design and construction under static and seismic loadings. Both static and seismic analyses of a typical section of tailings earthen dam is presented in this paper. The dynamic soil-structure interaction analysis is performed using FLAC^3D (2006). Different conditions of reservoirs with and without compacted tailings under both filled up and empty slurry bed conditions are used in the analyses for an actual waste disposal site in India. Various input earthquake motions have been used for the seismic analysis. It is observed that the maximum displacement of crest increases significantly under seismic loading than at static loading condition. Also the seismic slope stability analysis shows a significant reduction in factor of safety of such tailings dam from static loading condition. Significant loss of shear strength is observed in the tailings portion by conducting the liquefaction potential analysis.