Coal mining activities carried out for 200 years in Upper Silesia have had a negative effect on buildings. T his impact is in all cases related with continuous deformations of the surface and in certain cases with discontinuous deformations (mostly cave-ins), changes in water relations and mining tremors. T he paper presents an evaluation of the impact of a mining activity on a building situated in the Upper Silesian Coal Basin. T he building was affected by continuous deformations and mining tremors. Calculations were made of the values of deformation rates by means of Budryk–Knothe’s theory, which were partly verified on the basis of the results from geodetic measurements. An analysis of the velocity and acceleration of basement vibrations caused by mining-induced tremors was also conducted. T he conclusions included a high consistency between the results obtained on the basis of calculations and the values obtained by means of PGA and PGV measurements. In the case of tremors with the highest energy in the hipocentrum, there an empirical formula allowing for calculation of PGA value in given geological and mining conditions was also proposed. T he application range of the formula mentioned above is obviously limited only to the conditions in consideration. The presented conclusions indicate that at present, sufficiently precise methods, allowing for calculations for practical purposes, not only of deformation indices’ values, but also of PGV and PGA values, presently exist.

According to analyses of results of surveying measurements, description of undefined subsidence, performed with the use of S. Knothe's model is characterised by the sufficient coherence with results of measurements since the moment when the full subsiding trough becomes visible on the terrain surface. Lower coherence with results of measurements appears in the initial period after commencement of exploitation. In order to improve the quality of description within the initial phase of subsidence, a mathematical model has been developed, which is based on relations between the coefficient of the velocity of subsidence and the time co-ordinate, and from geometric co-ordinates. Obtained solutions have been verified basing on results of surveying measurements, with the use of a special computer software.

In the Upper Silesian Coal Basin (Poland), numerous former workings have been left unprotected after the liquidation of mines in the 19th and the beginning of the 20th century. The workings have been located at low depths. The paper presents the results of strength tests of wood samples acquired from linings in former workings, and the obtained results have been compared to the results achieved in tests of samples of wood intended to be used in a reconstruction of a historic gallery. The tests consisted in determining the bending strength of wood in compliance with the applicable Polish standard. The results showed that the wood from historic mines was characterised by high variability of bending strength – usually much lower than that of the wood intended for construction. Too low bending strength of timber may result in caving in shallow excavation and lead to sinkhole creation on the surface.

The issues covered by the work are important and topical as sinkholes that develop in large numbers over shallow mining excavations pose a great threat to public safety. In Upper Silesia (Poland), the formation of sinkholes can be observed even for a period of over 100 years following the termination of mining works. An effective method of risk elimination consists of filling the voids with a binding material with strength properties similar to those of the rocks surrounding the void. The application of fly ash is very suitable for this purpose, the use of which also has an ecological aspect. The literature studies presented in the paper indicate the possibility of making mixtures with the use of fly ash that has the required strength parameters. The compressive strength of the mixtures after solidification is up to 3 MPa, or even up to 7 MPa, and in some cases, up to 15 MPa. Most of the voids at shallow depths are found in coal seams, in which the compressive strength at shallow depths amounts to approx. 5 MPa. Thus, by filling the void with such material, we can ensure conditions similar to those prevailing before the excavation was made. The paper presents a case study involving the formation of a sinkhole above a dog heading and an ex post forecast made with the use of two selected methods. These methods yielded results affirming that the development of a sinkhole in the considered conditions is certain. Then, using the said methods, the impact of the filling level of the void on the possibility of sinkhole development was analyzed. The obtained results indicated the necessity to fill the void to around 90% with the use of one of the methods and its complete filling with the use of the other method.

The geopolitical situation in Europe has changed dramatically due to the war waged by the Russian Federation in Ukraine. This makes it necessary to become independent from supplies of mineral resources, especially energy from Russia. According to the authors, ensuring Poland’s energy security will require a longer use of coal as the primary energy resource than initially expected. The expected increase in energy demand may cause a negative energy balance in the country. Renewable energy sources dependent on weather conditions cannot with certainty ensure energy security. On the other hand, nuclear requires large financial outlays and a longer time for reactors’ construction. In addition, it has other disadvantages (the problem of waste, environmental impact in the event of a malfunction and the need to import uranium). In these circumstances, coal may be a raw material that meets the economic needs and ensures the energy security of the country.

The paper presents an example illustrating the problems of assessing the causes of damage that occurred to building structures located in mining and post-mining area. It is frequently necessary to determine whether probable damages came from other, non-mining causes or were caused by underground mining. This issue is particularly significant when it comes to monumental, historical objects because the cost of repairs is typically very high. The purpose of this work is to demonstrate, using the magnificent church as an example, that damage to building objects situated in mining areas does not necessarily result from mining activities. As a result, every such situation should be thoroughly evaluated to determine whether such a relationship exists. For the assessment of such a conclusion, multidirectional studies in the framework of this work were carried out: hydrogeological, mining and technical factors that cause the damage to the church building in question were analysed.