Under inactive conditions, these uncertainties become even more critical, since the facility must ensure long-term stability without continuous operational control, while being subjected to seismic loading and hydrogeological variations. In this context, closure design requires a comprehensive, risk-based geotechnical assessment, in alignment with standards such as the GISTM (ICMM, 2020) and CDA (CDA, 2019).

The case study corresponds to an inactive upstream tailings storage facility, with coarse tailings embankments and a fine tailings basin that produce a heterogeneous stratigraphy, including zones potentially susceptible to liquefaction and a variable piezometric regime, particularly beneath intermediate embankments.

The objective of this study is to evaluate long-term stability conditions and define geotechnical closure criteria for an upstream facility, integrating international standards.