Wyniki wyszukiwania - BazTech

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Contribution to the a priori assessment of the value of the caving zone expansion coefficient in the forecast of ground surface uplift caused by the flooding of closed coal mines in the Ruhr region/Germany

Rafał Misa, Mateusz Dudek, Anton Sroka, Krzysztof Tajduś, Dawid Mrocheń

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 2

art. no. e148611

EN

The article presents a methodology for determining the value of the expansion coefficient of a reconsolidated caving zone in the context of forecasting the rise in underground mine water levels and consequent surface subsidence caused by the process of flooding the closed coal mines. The paper also provides a brief characterisation of analytical predictive models regarding surface subsidence during the process of flooding coal mines. In order to describe the vertical deformation of the reconsolidated porous rock mass in the caving zone, a linear-elastic medium of Biot was utilised. The conducted theoretical calculations demonstrate a high agreement with the results obtained through the identification of the expansion coefficient parameter based on the analysis of in-situ subsidence measurements in Dutch and German mining areas. The proposed methodology was applied to a real case study involving the forecasting of the impact of the flooding process on the underground workings of the German Ibbenbüren mine. The article constitutes a significant contribution to the field of forecasting the rise in underground mine water levels and surface subsidence during the process of flooding closed coal mines. The presented methodology and obtained results can be valuable for researchers, engineers, and decision-makers involved in the planning and management of mining areas.

2

Analysis of steel industrial portal frame building subjected to loads resulting from land surface uplift following the closure of underground mines

Dudek Mateusz, Rusek Janusz, Tajduś Krzysztof, Słowik Leszek

Archives of Civil Engineering

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2021

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Vol. 67, nr 3

283--298

EN

The liquidation of underground mines by the flooding leads to movements of the rock mass and land surface as a result of pressure changes in the flooded zones. The changes resulting from the rising water table caused by the changes in the stress and strain state, as well as the physical and mechanical properties of rock layers, can lead to damage to building structures and environmental changes, such as chemical pollution of the surface water. For this reason, the ability to predict the movements of rock masses generated as a result of mine closure by flooding serves a key function in relation to the protection of the land surface and buildings present thereon. This paper presents an analysis of a steel industrial portal-frame structure under loading generated by the liquidation of a mine by flooding. The authors obtained land surface uplift results for the liquidated mine and used them in a numerical simulation for the example building. Calculations were performed for different cases, and the results were compared to determine whether limit states may be exceeded. A comparison was made between the cases for the design state and for additional loading caused by the uplift of the subsurface layer of the rock mass.

PL

Likwidacja podziemnych kopalń przez zatapianie prowadzi do ruchów górotworu i powierzchni terenu w wyniku zmian ciśnienia w strefach zatapianych. Zmiany wynikające z podniesienia się zwierciadła wody podziemnej, spowodowane zmianami stanu naprężenia i odkształcenia oraz właściwości fizycznych i mechanicznych warstw skał mogą prowadzić do uszkodzeń powierzchniowych obiektów budowlanych oraz zmian środowiskowych, takich jak chemiczne zanieczyszczenie wód przypowierzchniowych. Z tego względu możliwość przewidywania ruchów górotworu powstających w wyniku likwidacji kopalń przez zatapianie pełni kluczową funkcję w odniesieniu do ochrony powierzchni terenu i znajdujących się na nim budynków. W artykule przedstawiono analizę przemysłowej stalowej hali magazynowej pod obciążeniem wynikającym z likwidacji kopalni w wyniku jej zatapiania. Autorzy uzyskali wyniki wypiętrzenia terenu zlikwidowanej kopalni i wykorzystali je w symulacji numerycznej przykładowego budynku. Obliczenia przeprowadzono dla różnych przypadków, a wyniki porównano w celu określenia, czy możliwe jest przekroczenie stanów granicznych. Dokonano porównania pomiędzy stanem projektowym i dla dodatkowego obciążenia spowodowanego wypiętrzeniem przypowierzchniowej warstwy gruntu.

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Co-seismic and post-seismic deformation, field observations and fault model of the 30 October 2020 Mw = 7.0 Samos earthquake, Aegean Sea

Ganas Athanassios, Elias Panagiotis, Briole Pierre, Valkaniotis Sotiris, Escartin Javier, Tsironi Varvara, Karasante Ilektra, Kosma Chrysanthi

Acta Geophysica

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2021

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Vol. 69, no. 3

999--1024

EN

On 30 October 2020, a large Mw = 7.0 earthquake occurred north of the island of Samos, Greece. Here we present the characteristics of the seismic fault (location, geometry, geodetic moment) as inferred from the processing of geodetic data (InSAR and GNSS). We use the InSAR displacement data from Sentinel-1 interferograms (ascending orbit 29 and descending 36) and the GNSS offsets from fourteen (14) stations in Greece and Turkey to invert for the fault parameters. Our inversion modelling indicates the activation of a normal fault offshore Samos with a length of 40 km, width of 15 km, average slip of 1.7 m, a moderate dip-angle (37°) and with a dip-direction towards North. The inferred fault is located immediately north of, and adjacent to Samos with the top of the slip ~ 0.6 km below surface, and ~ 1 km offshore at its closest to the island. Near the fault, the earthquake caused the permanent uplift of the island up to 10 cm with the exception of a coastal strip along part of the northern shore that subsided 2–6 cm. The co-seismic horizontal motion of GNSS station SAMO was 35.6 cm towards south and 3 cm towards west. A post-seismic signal (22–33% of the co-seismic on the vertical component) was observed at GNSS stations SAMO and SAMU, with a time constant of 30 days. The effects of the earthquake included liquefaction, rock falls, rock slides, road cracks and deep-seated landslides, all due to the strong ground motion and associated down-slope mobilization of soil cover and loose sediments.

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O problemach w modelowaniu deformacji powierzchni terenu w aspekcie budownictwa na terenach górniczych

Paleczek W.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2018

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Z. 24 (174)

267-272

PL

Przedstawiono rozwiązanie zadania modelowania obniżeń powierzchni terenu i górotworu, w którym uwzględniono jednoczesne występowanie: wstępnych przemieszczeń pionowych, asymetryzacji i wypiętrzeń. Podane wzory obliczeniowe opracowano na podstawie studium teoretyczno-empirycznego. Mogą być one przydatne do celów inżynierskich i konstrukcyjnych przy zastosowaniu w modelowaniu konstrukcji i budownictwie na terenach wpływów podziemnej eksploatacji górniczej.

EN

The paper presents a solution to the problem of modeling the depressions of terrain and rock mass, in which simultaneous occurrence of: initial vertical displacement, asymmetrization and elevation was taken into account. The calculation formulas given have been developed on the basis of a theoretical and empirical study. They can be useful for engineering and construction purposes when used in modeling structures and construction in the areas of underground mining exploitation.