Observations of building structures in mining areas, reveal the occurrence of periodic and permanent excessive loading situations. These include ground deformations associated with the extraction of underground mineral deposits. In urban areas, these deformations significantly alter the operating conditions of building structures. For this reason, forecasts of ground transformation and analyses of possible changes in the technical condition of buildings on the ground surface are made in advance, even before mining is commenced. Taking into account previous in-house experience of the observed effects of mining impacts on building structures, an original method of monitoring changes in the condition of these structures has been developed. The aim of the monitoring is to record phenomena that change the operating conditions of the structures. In the developed method, measurements are made quasi-continuously using strain and deflection sensors mounted directly on structural elements. In the mining area affected by the mining operation being carried out in the years 2020 - 2022, and with a further one planned in the years 2023 - 2024, through the extraction of 14 coal parcels, three public utilities of special interest were monitored. The measurement results of deformation changes in the elements allow for an assessment of changes in the stress state of the structures, and the integration of sensors mounted on the structures into a wireless network fulfils the demands for maintaining public safety conditions in mining areas. It also contributes to the analysis of fatigue issues in masonry structures due to long-term multidirectional loads.
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Dopasowanie prognozy deformacji górniczych do rzeczywistych, ujawnionych w terenie stanowi podstawę prawidłowo dobranej profilaktyki budowlanej oraz poprawnie sformułowanych wniosków na temat powstałych szkód górniczych. Z tego względu badania porównawcze wartości wskaźników deformacji powierzchni obliczonych dla parametrów dokonanej eksploatacji górniczej i pomiarów terenowych należą do ważnej części obserwacji in situ w górnictwie podziemnym. Są one również częścią badań nad skutkami oddziaływań górniczych w obiektach budowlanych i infrastrukturze technicznej zabudowy powierzchni. W artykule opisano badania wyników wstecznej prognozy górniczej w kontekście analizy czynników wpływających na pogorszenie stanu technicznego obiektu liniowego, odcinka drogi publicznej i towarzyszącej jej infrastruktury.
EN
Matching the prediction of mining deformation with the actual deformation revealed in the subsurface is the basis for properly selected construction prophylaxis and correctly formulated conclusions about the resulting mining damage. For this reason, comparative studies of the values of surface deformation indices calculated for the parameters of the completed mining operation and field measurements are an important part of in situ observations in underground mining. They are also a part of the study of the effects of mining impacts on buildings and technical infrastructure of surface development. The article describes the study of the results of the backward mining forecast in the context of the analysis of factors affecting the deterioration of a linear object, a section of a public road and its accompanying infrastructure.
Human activity causes transformations in the near-surface layers of the rock mass, which result in long-term impacts on buildings and engineering infrastructure. Mining activities are particularly disadvantageous in this context, as they trigger severe deformation processes that reach the soil surface as a result of the excavation of deposits. The prevention of accidents and disasters caused by these impacts is based on knowledge derived from observation. Therefore, the aim of this study was to acquire and update knowledge on the impact of mining-related ground deformation and tremors on buildings. The paper presents the results of measurements carried out on a group of buildings located in an underground mining area. The buildings have been affected by mining impacts since their construction in the 1980s. Despite the implementation of appropriate structural protection, the structures have been suffering deformation and damage. For the purposes of the study, two two-axis inclinometers were installed on the 15.2 m high bell tower, taking measurements at 6-hour intervals. Over a period of 10 months, changes in the leaning of the tower were measured and the condition of the other buildings observed. The study resulted in obtaining: values for the change in tilt of the two perpendicular walls of the tower (over a period of 10 months),correlation of the results with tremors measurements and periodic surveying measurements of the inclination of the vertical edge of the tower, image of damage to buildings caused by mining deformation of the ground. On the basis of an analysis of the location and timing of minefields excavation, the occurrence of real ground movement in the mining areas, continuing even after the end of mining works, was confirmed and irregular deformation of the originally perpendicular walls of the masonry tower building was demonstrated. The tower did not behave as a rigid body; its horizontal profile was deformed.
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