Slope stabilisation using advance dewatering techniques in a large opencast mine in North-Western Spain

Abstract

The paper describes the geological and geotechnical behaviour of a side wall slope of an open cast excavation in a large lignite mine in North-Western Spain. The details of an hydrogeological investigation are given in order to establish the relationship between the structural and lithological behaviours of the rock mass, of Tertiary and Paleozoic ages, and the ground water conditions in the host rock. The largest geological structures occuring in the area are related to a complex systems of folds and faults. It was obvious, from the very onset of the investigation, that the side wall slope would be unstable without reducing the water pressure in the host rock by application of advanced dewatering techniques.