Assessment of regular behavior and stability of tailings dams by comparing calculated and measured displacements

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, indicate that the procedures and techniques in the design, construction, maintenance and technical monitoring of the embankment dams for water storage were not applied to the tailings dams, with the same carefulness and the proper caution. The comparison of the calculated and measured horizontal and vertical displacements in the tailings dam post-service period is necessary to make the valid conclusion about the regular behavior and for the satisfactory stability of these complex heterogeneous earth-fill structures. In this paper, the calculated displacements from the numerical model of the static analysis of the hydro tailings dam Topolnica are compared with the measured values from geodetic, as a part of the monitoring process. The combined tailings dam Topolnica of the copper/gold mine Buchim, Radovish, in the east part of RN Macedonia, is formed by downstream (in the first stage, dam No. 1) and upstream (in the second stage with two phases, dams No. 2-1 and No. 2-2) method of construction, with total height from the crest of the highest dam to the downstream toe of the dam of 141.2 m.