Water that floods the mining complexes is drained on a constant basis when a mine is still active, but the situation changes the moment the mine is closed. This article presents the influence that flooding of mine workings has on a surface of a mining area using computer simulation. The evaluation of potential changes to the surface and scale of this phenomenon has been done using as examples the exploitation of mine deposit layers 702, 705, and 718 of the old Gliwice and Pstrowski mines. The performed numerical simulation showed that using numerical modeling of rock mass demonstrates the possibility of predicting uplifting of the surface caused by flooding of underground workings. Maximum designated value of surface uplifting amounts to around 34 mm/m. This value is relatively small and does not exceed 2% of subsidence caused by previous mining activity.

A detailed description of carbonate minerals of Triassic dolomites with different magnesium contents is presented in this article. Tests were carried out to determine geochemical and mineralogical characteristics. The following carbonate phases were identified: low-Mg calcite, high-Mg calcite, proto-dolomite, ordered dolomite, and huntite. The methods used were microscopic description, X-ray diffraction (XRD), X-ray fluorescence (XRF), and electron probe microanalysis (EMPA). Samples were collected from the Tarnowice Formation, which is the lower part of the profile of Upper Muschelkalk. On the basis of the obtained results, the chemical formulae of carbonate phases were calculated. The results indicate that Mg in low-Mg calcite ranges from 0.6 to 1.2% and in high-Mg calcite from 7.47 to 10.41%. In protodolomite, it ranges from 10.96 to 11.78%. In ordered dolomite, the Mg content is 13.18% on a stoichiometric basis. Due to the reduced Mg content in the identified huntite (in the range of 13.62% to 17.76), this carbonate phase is considered de-huntite.

In post-mining areas where hard coal mining took place under a thick overburden of carbonate rocks, there are often geomechanical threats occurring to the designed and existing buildings. They manifest by the occurrence of post-mining voids and deformations created in the Carboniferous layers and related to erosive processes, including karst ones occurring in the rock environment carbonate. Various geophysical research methods, including electrical resistivity imaging, find application in the assessment of deformations in the rock mass. Geophysical surveys may be applied to assess the necessity of carrying out treatment and protection works, e.g., borehole injection and determination of the boreholes‘ number and location. The paper presents two case studies of geophysical surveys using the method of two-level electrical resistivity profiling (ERP) and electrical resistivity tomography (ERT) in two adjacent research areas with a similar geological structure and a similar scope of mining operations. Based on the analysis of the obtained results, injection of voids and zones of a loosened ground in both areas was designed and executed. The analyzed cases have shown that methods of geophysical ground investigation based on electrical resistivity imaging provide accurate forecasting of the bedrock structure and can be used in practice to reliable determination of the threats to the ground surface from discontinuous deformations and their successful elimination. The authors of this article performed the following research and their interpretation independently. They have appropriate geological and geophysical qualifications and many years of practical experience. The above allowed us to present in this article the issue, the need to select and the course of geoengineering procedures in areas where, on the one hand, shallow mining operations were conducted, and on the other hand, the presence of complex geological conditions (karst phenomena) was found.

The state-of-the-art methods for verifying the correctness of ground improvement performed using the DSM (Deep Soil Mixing) technology are largely focused on the selection of adequate factors impacting the achievement of a correct compressive strength f_c [MPa] of the column core, which ensures the transfer of stress from the designed structures to the subsoil. In view of the operation of each of the columns, it is equally significant to ensure that their bases are located in load-bearing soil at the entire area of the improvement, without the need to perform many costly subsoil surveys. Based on the complementary soil investigation results and parameters obtained during deep soil mixing from an automatic logger installed on the drilling machine, a method of comparing the rotary drive pressure (working pressure) PKDK [bar] and the cone resistance q_c [MPa] of the CPTU static probe (Cone Penetration Test Unit with Pore Pressure Measurement) was developed along with the method to interpret the results in the context of the correctness of the ground improvement on the construction site analyzed in this paper.

Detailed description of phase composition and geochemistry of the Muschelkalk carbonate rocks of the Upper Silesian Province in Poland were presented in this article. The tests were carried out to determine mineralogical features and geochemical properties. The samples were collected from the formations of the Lower Muschelkalk (Gogolin Unit), Middle Muschelkalk (Diplopore Dolomite Unit) and Upper Muschelkalk (Tarnowice Unit, Boruszowice Unit). The following research methods were used: macroscopic description, X-Ray Diffraction, Fourier transform infrared spectroscopy, X-Ray Fluorescence and Atomic spectrometry with plasma intensification. The following carbonate phases were identified: a low-Mg calcite, a high-Mg calcite, a proto-dolomite, an ordered dolomite and a huntite. The results of XRD analysis allowed the determination of the chemical formulas of the mineral phases. XRF and ICP AES analyses allowed to establish the content of following trace elements: Sr, Ba, Al, Si, Fe, Mn, K, Na, S, Cl, Ti, Cr, Ni, Zn, Rb, Zr, Pb, As, V, Be, B, Co, Cu, Br, Mo and Cd. Apart from Sr and Ba, they are not fundamental components of carbonate rocks. They indicate the presence of minerals such as silicates, aluminosilicates, oxides and sulfides.