The topic of residual subsidence is important in Europe as it defines possible surface deformation for closed mine areas. It has to be determined because of potential financial claims and damages of sensitive objects such as satellite dishes, precision mechanics objects, agriculture, forestry and hydrogeology, etc. Analyses of measured subsidence after the end of mining exploitation indicate that this process can last from several months to several dozen or even several hundred years, and the final surface subsidence is not known. It is dependent on the individual’s features of excavated medium, depth of exploitation, a system of exploitation, behaviour of surrounding rock masses, etc. In the article, the authors analysed the assessment of the subsidence process after the end of mining operations, based on the innovative method. This concerns the duration of the subsidence process and the size of the expected subsidence. The methodology was applied to the RAG Aktiengesellschaft company project where prognostic calculations were made for seven closed coal mines using unique results of precise height measurements carried out for more than 90 years by the German State Office for National Measurements (Landesvermessungsamt NRW) under the so-called levelling measurements net. These measurements are carried out every 2 years and serve to keep the altitude network in the whole state of Rhineland Westphalia up-to-date. The result of the prognosis for one case study, German mine Auguste-Victoria, is presented in the article.

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.

This paper presents the authors' computational methods based on Knothe's theory. The methods enable the estimation of the reduction coefficient for effects which originate from mining operations performed via the application of a longitudinal structure which is sunk in to the ground. It could be, for example, a partition, which as a structural gap fulfils the function of an expansion grout, or via breaking the subsoil continuity (e.g. because of creating a peat-filled ditch or using a natural gap). Demonstrative calculations have been carried out in a few cases, i.a. to protect a structure situated in the vicinity of a planned tunnel. Additionally, some examples of the discontinuity zone which impact the obtained deformation values have been presented. The calculation method has been tested in case studies. The results of the calculations clearly show the positive influence of the applied geotechnical solutions on the minimisation of mining damage.