Back-analysis of the Patrimônio slope failure

A failure involving a 240-meter high slope occurred at the northwestern corner of the Águas Claras Mine, Brazil, in 1992, causing several problems to the mine operation, as well as disturbance to the Patrimônio Ridge, which is protected by law. Back-analysis of this failure was performed, using two and three-dimensional numerical methods (FLAC and FLAC3D). The nature of the failure, its mechanisms and controlling parameters could be determined with relative precision. The suitability of numerical methods for back-analysis of failed slopes was verified, with special consideration being given to three-dimensional analysis.