Assessment and Duration of the Surface Subsidence after the End of Mining Operations

Abstract

The change in the European Union’s policy related to the energy transformation of Europe and the departure from fossil energy resources may contribute to the accelerated closure of many coal mines. Therefore, it is necessary to solve the problem of surface subsidence after the end of underground mining and the related suitability of post-mining areas for the re-use of the so-called problem of the reclamation of post-mining areas. In the case of areas suitable for re-use, it is necessary to determine the value of the final subsidence. It is also important to specify the time after which mining influences will no longer have a significant impact on the surface infrastructure and the environment. Analyses of the observed subsidence after the end of the mining operation indicate that this process may last from several months to several dozens or even several hundreds of years. It depends on the individual characteristics of the mining area, including the depth of exploitation, mining system, the behavior of the surrounding rock mass, etc. The article presents an in-depth analysis of residual subsidence and its duration using the proprietary forecasting method and the Gauss–Markov algorithm based on the example of the German Lohberg mine (Ruhr District), whose mining activity was completed in January 2006.