ABSTRACT
One of the most common practices for valorisation of abandoned open-pit mines is flooding them to form pit lakes. The present work numerically examines stability issues for a horizontal water table being elevated from the bottom to the top of an open-pit, initially with the limit equilibrium method. During the water table’s elevation, the safety factor gradually decreases until the water’s height reaches 40% of the total height. It then increases and becomes larger than the initial one when the water table reaches full height. The maximum safety factor decrease is approximately 10% and thus, flooding does not affect significantly the slope stability Furthermore, limit equilibrium analysis results are compared and validated with the finite element method. Finally, analyses of slopes with and without benches, but of the same overall angle, are performed and compared. The omission of benches is always more conservative, leading to smaller SFs by 6%-14%.
