Numerical analysis of seismic stability of a high centerline tailings dam

Abstract

Rapid growth of mining activities parallel with recent technological progresses in this field has led to continuous production of great amounts of mining waste. Tailings dams are constructed to safely store these materials in order to protect the environment and water resources against mineral and chemical contaminations. However, the high rate of failure in these structures -especially under dynamic loads- has become a major concern for the mining industry as well as environment protection authorities. Considering the importance of these dams’ role and their stability in protecting the environment, this paper analyzes the dynamic behavior of a high centerline tailings dam in order to evaluate its stability. To achieve this goal, a coupled stress-pore pressure analysis is carried out by SIGMA/W software to study the dam's behavior during and at the end of staged construction. Then, the structure's dynamic response to different seismic criteria relevant to the area of interest is investigated using the QUAKE/W software to determine the history of acceleration at the dam's crest and liquefied zones in the impoundment. Permanent deformations are then determined by a stress redistribution analysis conducted by SIGMA/W software and performance of the dam is evaluated accordingly. Analyses results show that the studied dam is stable under weak ground motions, but unstable under stronger seismic inputs.