Guidelines and recommendations on minimum factors of safety for slope stability of tailings dams

Abstract

Recent major upstream raised tailings dam failures have led to a reopening of the discussion of the validity of some of the existing routine practices within the profession. De-spite its many shortcomings, deterministic slope stability limit equilibrium analysis is and will continue to be, at least for some time ahead, an important tool for tailings dams’ safety assessment. Within this context, this paper presents a contribution to the postula-tion of minimum factors of safety required for tailings dams’ slope stability analysis. A recent review and discussion of limit equilibrium analysis and the guidelines of international standards and current trends, with focus on tailings dams, are presented. Based on this review, and the authors’ academic and professional experience, minimum required factors of safety recommendations are proposed. The framework of the recommendations strives to conciliate, in a simple manner, the deterministic minimum required factors of safety with concepts of consequence, uncertainties, risk and characteristics of loose tailings behaviour as a material.