CONSTRUCT-GEO team led by Sara Rios has recently won the project SAFETY, a transnational access project financed by the Horizon2020 GEO-LAB call. The project will fund the execution of four centrifuge tests to be performed in DELTARES, Delft, Netherlands, to analyze the stability of tailings storage facilities. The team comprises academic partners (CONSTRUCT-FEUP and CIMNE-UPC- Barcelona), a consultancy company and VALE mining company. CONSTRUCT team counts with Sara Rios, António Viana da Fonseca and two PhD students (Isabela Caetano and Jesse Carneiro).

Mine tailings are the finer waste material that remains after extraction of the economic part from the mineral ore. Traditionally, tailings are deposited in dams but, due to their high risks expressed in recent catastrophic failures, another approach is being explored concerning the deposition of filtered tailings in stacks. The strength of these stacks will depend on the type of material, degree of saturation and compaction, as well as drainage conditions, effective stresses due to loading and/or excess pore pressure generation requiring effective stress-strain analysis and appropriate constitutive models. 

Simple slope models built with iron tailings from Brazil (fully characterized in FEUP geotechnical laboratory with advanced tests) will be tested in the centrifuge where a hydraulic gradient will be imposed during flight. The aim is to analyze the stability of these structures when the water table rises inside due to heavy rainfall or inefficient drainage.

The tests will be reproduced in advanced numerical analyses to calibrate constitutive model parameters. The optimum parametric protocols will be used to simulate other embankment geometries or ground improvement solutions. The results will be interpreted aiming to optimize stability analysis procedures in such sensitive materials.