Centrifuge tests on liquefaction potential and slope stability of mine tailings

Abstract

Several factors have led to the extended need for investigation of the static and dynamic behaviour of mine tailings and include the rising generation and surface storage of mine waste, its frequent use as a construction material for the retaining structures and the relatively high rate of associated failures, with seismic liquefaction being a rather common cause. In this experimental study, dynamic response and surface slope stability of a layered mine tailings deposit were examined by means of four centrifuge tests performed at the Center for Earthquake Engineering Simulation (Rensselaer Polytechnic Institute). The material under study was fine copper–gold tailings and the varying parameters were average degree of consolidation prior to dynamic loading and base acceleration amplitude. The material was found to be liquefiable and its performance in terms of acceleration, shear strain, slope stability, residual lateral deformation, pore-pressure build-up and liquefied depth was somewhat dependent on the aforementioned parameters. The response of the deposits changed with increasing depth and effective stress, which made centrifuge testing highly advantageous.