Stability analysis of Żelazny most tailings dam loaded by mining-induced earthquakes

Abstract

The paper presents the stability analysis of Ż elazny Most tailings dam subjected to mining-induced paraseismic events. The tailings dam as well as foundation have complex geotechnical structure. The foundation of the dam is built of series of tertiary and quaternary formations affected in the past by three glaciations whereas the complexity of tailings structure results from the method of its deposition within the pond. Simplified dynamic displacement analysis of the dam is performed based on Newmark’s approach using GeoStudio2007 software. The paper highlights the necessity of proper domain and time discretization, especially in the case of complex geological structure. Dynamic response of the tailings dam was obtained for the equivalent linear one-phase soil model. Stability calculations were performed for Coulomb-Mohr model and Stress History And Normalized Soil Engineering Properties (SHANSEP). The applied input signals were selected by Arias intensity criterion from huge set of signals recorded on the ground surface caused by mining tremors. The peak ground acceleration value was scaled to the values predicted by hazard analysis. The results of the calculations carried out for three selected acceleration signals have revealed no permanent deformations.