Resume/ Abstract

Failures of tailings dams, primarily due to liquefaction, have occurred in Brazil in recent years. These events have prompted the Brazilian government to place restrictions on the construction of new dams (and even requesting decommissioning them), as ore tailings deposited behind upstream dams by spigotting have been shown to have low in situ densities and strengths and are prone to failure. This research proposes a new trend for tailings disposal: stacking compacted filtered ore tailings (with and without cement blends) reaching up to 300 metres high. It analyses the behaviour of compacted ore tailings–distinct (from zero to high amounts) cement blends, considering distinct compaction degrees. With the intention of evaluating the stress–strain–strength–durability behaviour of the blends, the following tests were carried out: unconfined compression tests; pulse velocity tests; wetting–drying tests [for cemented specimens, postulating an analysis centred on the porosity/binder index (η/B_iv)]; and drained/undrained triaxial compression tests with internal measurement of strains considering low to very high pressures. Critical State Soil Mechanics Theory was related to such clastic and anthropic geomateriais.