Geotechnical Hazards and Their Potential Effects in Case of Flooding Former Open-pits

Controlled flooding of the remaining gaps of former open-pits (especially lignite open-pits) and the
formation of lakes that can take different uses is one of the ways of recovering and rehabilitating
degraded mining lands which offer opportunities for sustainable development of a mining region. The
advantages of such a solution are multiple, starting from the restoration of biodiversity, to economic
and social benefits. Basically, several flooding techniques are known, but depending on the
geological, geotechnical, hydrological and hydrogeological conditions characteristic for a particular
region, these techniques must be adapted to the risks that may arise before, during and after flooding
the remaining gap. Most of the times, the risks are of geotechnical nature and arise as a result of the
interaction between the rocks and the mixture of loose rocks that form the final slopes and the dump
with water. Geotechnical hazards (risks) arises when a potential ground movement can be identified.
The paper is part of an extensive research, which is carried out under the concrete conditions of the
remaining gaps in the Rovinari mining basin, and essentially aims at: identifying the main categories
of geotechnical hazards that can occur under the given conditions, determining the triggering factors,
the mechanism of producing of negative geotechnical phenomena and their effects on environment,
as well as to identify the main measures to avoid them.