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Agnieszka Malinowska

Abstract

Methods used for evaluating damage risk of buildings threatened with continuous strains generated by underground exploitation have been addressed in this paper. The main emphasis was put on methods thanks to which the degree of damage of a large group of structural objects could be approximated. The investigations were focused on the origin of those methods, especially the assumed criteria. The final stage of theoretical study was a comparative analysis of presented methods, thanks to which the basic differences between assumptions to those methods as well as the main advantages and disadvantages could be enumerated. Then the damage risk of buildings was evaluated with selected methods. The obtained results were compared with actual data registered in those objects. This enabled the authors to practically evaluate the adaptability of those methods to the underground exploitation conditions in Poland. The first part of the paper is devoted to the presentation of methods and theoretical anaysis of their shortcomings and advantages, followed by the results of analyses performed on actual data.

Open access

Agnieszka Malinowska

Abstract

This paper is a continuation of theoretical analyses of World’s methods used for assessing damage risk to buildings with continuous strains, which were presented in Part 1. The authors focus only on those methods in which the scale of damage to buildings can be approximated. Selected methods were tested on 100 random objects sited in hard coal excavation-induced areas. The efficiency and effectiveness of those methods was evaluated. The damage risk was also verified with the use of a method currently used in Poland. The efficiency results obtained for World’s methods and the one used in Poland turned out to be comparable. Practical studies were made to evaluate the adaptability of those methods in the underground exploitation-induced conditions in Poland.

Open access

Agnieszka Malinowska, Ryszard Hejmanowski and Janusz Rusek

Abstract

The research presented in this paper is basically focused on two objectives. Firstly, the selection of parameters affecting the water supply network damage. The causes of failures were selected from a population of tens of breakdown cases and then classified in view of their importance. Secondly, attention was paid to the selection of the most suitable linguistic model which could be commonly used for selecting factors which generate failures. Finally a Mamdani-based model could be worked out as a system possessing best generalization qualities. This model can create bases for an adaptative decision system which can show the type of water supply-sewage network, depending on continuous surface strains due to the mining activity.

Open access

Stanisław Barycz, Karol Firek, Wojciech Kocot and Agnieszka Malinowska

Abstract

The article presents the case study of a historical religious building located in the area of “Bogdanka” S.A. Coal Mine. As the building lacked adequate resistance to the expected effects of mining, the Mine undertook efforts so that it was fully protected against mining impacts before the commencement of mining operations. A preventive conservation system was used, consisting of an external stiffening reinforced concrete plate at the ground level and a system of steel tie rods established at the level of vault supports. The article assesses the effect of undertaken preventive conservation measures on the current technical condition of the building. The basis for the assessment was the extent of damage to the building confirmed after the occurrence of impacts from the performed mining operations combined with the analysis of ground deformation.

Open access

Ryszard Hejmanowski and Agnieszka Malinowska

Streszczenie

Eksploatacja złóż gazu ziemnego i ropy naftowej w pewnych warunkach zalegania tych złóż może wywoływać deformacje ciągłe powierzchni terenu. Deformacje takie objawiają się w postaci niecek obniżeniowych o znacznym zasięgu i maksymalnych obniżeniach zależnych od całkowitej miąższości basenu, właściwości kompak-cyjnych skał i szeregu innych czynników. W historii zdarzały się niecki o maksymalnych obniżeniach dochodzących do 9 metrów. W niecce obniżeniowej występują także strefy naprężeń niebezpieczne dla infrastruktury technicznej i budynków. Deformacje takie mogą wpływać niekorzystnie na budynki i budowle, ale także na infrastrukturę własną zakładów górniczych. Znane są przypadki zniszczenia otworów i ich uzbrojenia, bądź utraty ich szczelności. Z uwagi na to istnieje konieczność wykonywania analizy możliwości wystąpienia takich niekorzystnych zjawisk, monitorowania deformacji w trakcie eksploatacji złoża i ochrony infrastruktury zlokalizowanej w zasięgu wpływów eksploatacji. W artykule przedstawiona jest problematyka prognozowania deformacji powierzchni w warunkach eksploatacji złóż surowców ciekłych i gazowych. Przyjęto założenie o związku przyczynowo-skutkowym między kompakcją skały basenu a obniżeniem powierzchni terenu. Model obliczeniowy oparto na tzw. funkcji wpływów i superpozycji wpływów elementarnych. Dla celów ochrony obiektów i infrastruktury opracowany został model oceny zagrożenia obiektów bazujący na elementach logiki rozmytej. Model ten pozwala na uwzględnienie w analizach czynników ilościowych i jakościowych determinujących zagrożenie uszkodzeniem. Dzięki temu możliwe jest uzyskanie jednoznacznej wartości różnicującej zagrożenie poszczególnych budynków na danym terenie. Analizy przestrzenne, które pozwalają na uwzględnienie dużej ilości budynków mogą być wspomagane poprzez zastosowanie systemów GIS. W artykule zostało to zilustrowane na przykładzie praktycznym.

Open access

Ryszard Hejmanowski and Agnieszka A. Malinowska

Abstract

The modeling of strains and deformations in salt mine areas encounters considerable difficulties because of the varying strength properties of salt, the complex morphological build of dome deposits and the rheological properties of salt. These properties have impacted the development of salt extraction for hundreds of years and the fact that the accurate determining of strains in a given specified moment and place are burdened with high uncertainty. Numerical modeling is useful when the model is reduced to one or several salt chambers. A broader range of underground post mining void considerably lowers the accuracy and efficiency of the calculations of such models. Stochastic models allow for a 3D modeling of the entire mining complex deposit, provided the model has been parametrized in detail. The methods of strains and deformations modeling were presented on the example of one of the biggest salt mines in Europe, where a volume of over 21 million m3 of salt was extracted. The stochastic model could be parametrized thanks to the documented results of measurements of convergence of the underground mining panels and leveling on the surface. The use of land subsidence inversion in the least squares method allowed for estimating the optimum values of parameters of the model. Ground deformation modeling was performed using the two-parameter time function, which allows for a simulation to be carried out in time. In the simulation, the convergence of underground excavations and the transition in time the effects of convergence into ground subsidence was taken into account. The detailed analysis of the geological conditions lead to modeling deviation of the subsidence trough. The accuracy of the modeling results was qualitatively and quantitatively confirmed by a comparison of the modeled to measured values of the vertical ground movement. The scaled model can be applied in future mining extraction projects in order to predict the strains and deformations for an arbitrary moment in time.