This paper presents a probabilistic framework that integrates the 2nd Generation of Eurocode 7 geotechnical design principles with advanced numerical modeling to assess the vulnerability of TSFs to flow liquefaction under combined actions.
The procedure aims to support performance-based decision-making by accounting for spatial variability, uncertainty in strength parameters, and the probabilistic nature of external actions. The first component of the procedure addresses the statistical characterization of the undrained shear strength of tailings, using data from field and laboratory tests.
A procedure is presented to derive a probability density function for the peak undrained strength ratio by combining CPTu and triaxial test data using reliability-based weighting. This characterization is then employed in the construction of a vulnerability surface—a continuous function in action-space that defines the limit state of the TSF under combinations of crest load, beach width, and toe contraction. The vulnerability surface is treated as fuzzy due to the uncertainty in input parameters. By performing a Monte Carlo simulation over both the vulnerability surface and the distributions of external actions, the procedure yields an annualized probability of failure for a representative cross section of the TSF.
While this analysis focuses on a simplified configuration and a subset of uncertainties, it illustrates a path forward for incorporating reliability-based methods into TSF safety evaluations.
The methodology is intended as a contribution to the evolving practice of tailings dam design, emphasizing transparency, rigor, and continuous improvement through collaboration and shared learning.
