Application of SPT results on liquefaction phenomenon modeling of tailings dams

Abstract

The tailings dams, due to the enormous volume of the waste lagoon, are earth-fill structures with highest potential hazard for the surrounding. However, the numerous reports of collapses of the tailings dams in the last three decades, all over the World, indicate that the structural (static and dynamic) safety and the liquefiable resistance was not controlled with the proper carefulness. In this research, the concept of collapse surface is used for liquefaction assessment, which is defined by two parameters, the angle of inclination of the collapse surface and steady-state strength. The steady-state strength of the different zones of the tailings dam is adopted from the results obtained from “In situ” investigations by Standard Penetration Test (SPT) and laboratory tests of fines. In this paper are presented results from the analysis of the dynamic response, the liquefaction assessment and the seismic resistance of the hydro tailings dam Topolnica, of the mine Buchim, Radovish. This tailings dam, in the east part of Republic of Macedonia, is formed by combination of downstream (in the first phase) and upstream (in the second phase) method of construction, with total height from the crest to the downstream toe of the dam of 141.2 m.