Analytical fragility curves for abandoned tailings dams in North-Central Chile

Abstract

Chile has 173 abandoned tailings dams with unknown seismic vulnerability levels due to uncertainties in their design, construction, operation, and closure stages. The physical stability of these geo-structures concerns the local communities and authorities in areas with high seismic hazard, given their deficient performance during past mega-earthquakes. This work develops fragility curves to estimate the expected damage as a function of the spectral acceleration Sa(0.3 s), based on dynamic analyses of a representative 2D FEM model, subjected to ground motion records of interface earthquakes, following a Multi-Stripes Analysis. The proposed fragility curves provide the probability of attaining three damage levels for different yield seismic coefficients. Results indicate that abandoned tailings dams in Chile have significant probabilities of severe earthquake-induced damage for Sa(0.3 s) > 1 g.