Geotechnical and environmental impacts on the surface of the water rising in French underground coal mines after closure

Francis Wojtkowiak (1) , Jean-Christophe Couillet (1) , Xavier Daupley (1) , Christian Tauziède (1)

1 INERIS - Institut National de l'Environnement Industriel et des Risques

The water rising in underground coal mines, after their closure and, therefore, to the interruption of the dewatering pumping, may have non-negligible impacts of various types on the surface and on the environment. In the scope of numerous studies conducted in the various French coal basins, INERIS developed a study method to define the residual mining risks, as well as their potential impacts on the environment, resulting from the definitive closure of the coal mines. Amongst the main consequences of the flooding of mines on the environment, we will more especially deal with the impacts of the water rising on the stability conditions of the surface (risk of subsidence restoration or elevation of the ground; risk of collapse ...) and with the risks of gas emissions to the surface or even accumulations in places not or badly ventilated. The various phenomena and mechanisms that are at stake and the compensatory measures the most currently implemented to reduce and/or manage these risks are briefly depicted. Finally, a mathematical model to efficiently manage mine gas resource after the mine closure, while guaranteeing the safety of people and facilities and the protection of the environment, is more thoroughly detailed.

Keywords: FINAL CLOSURE; UNDERGROUND COAL MINES; WATER TABLE RISING; SURFACE STABILITY; GAS EMISSIONS; SAFETY OF MINEOPENINGS

Domains: Earth Sciences; Environmental Sciences

Francis Wojtkowiak, Jean-Christophe Couillet, Xavier Daupley, Christian Tauziède. Geotechnical and environmental impacts on the surface of the water rising in French underground coal mines after closure. 7. International Mine Water Association Symposium (IMWA 2000), Sep 2000, Katowice, Poland. pp.180-194. ⟨ineris-00972202⟩