Stability analysis and required geometrical modification of tailings dam heightening subject to static liquefaction

Abstract

The need to provide an additional volume for depositing tailings material, necessary for the regular operation of mines in conditions of spatial limitation, actualizes the heightening of the tailings storage facilities. The upgrade of the existing tailings storage facilities, with the upstream construction method of a new tailing sandy dams over the existing waste lagoon, is a heterogenic geo environment that is susceptible to liquefaction during static and dynamic (cyclic) loading and therefore they are the civil engineering structures with the highest stability risk. This upgrade is characterized by detailed geotechnical in-situ investigations, sophisticated structural analyzes (static, unsteady seepage, and dynamic), and modification of the geometry of tailings dam heightening, which are illustrated by the results of the stability investigation (in static conditions) of an upgrade of the existing up-stream diverting rockfill dam with clay core, with tailings sandy dam above the tailings deposition lake of the tailings storage facility Toranica, Kriva Palanka, Republic of North Macedonia, Europe.