Wyniki wyszukiwania - Biblioteka Nauki

1

Analytical design of selected geotechnical solutions which protect civil structures from the effects of underground mining

100%

Misa R. , Sroka A. , Tajduś K. , Dudek M.

Journal of Sustainable Mining

|

2019

|

tom Vol. 18, iss. 1

1--7

EN

This paper presents the authors' computational methods based on Knothe's theory. The methods enable the estimation of the reduction coefficient for effects which originate from mining operations performed via the application of a longitudinal structure which is sunk in to the ground. It could be, for example, a partition, which as a structural gap fulfils the function of an expansion grout, or via breaking the subsoil continuity (e.g. because of creating a peat-filled ditch or using a natural gap). Demonstrative calculations have been carried out in a few cases, i.a. to protect a structure situated in the vicinity of a planned tunnel. Additionally, some examples of the discontinuity zone which impact the obtained deformation values have been presented. The calculation method has been tested in case studies. The results of the calculations clearly show the positive influence of the applied geotechnical solutions on the minimisation of mining damage.

2

A new prediction model of surface subsidence with cauchy distribution in the coal mine of thick topsoil condition

88%

Jiang Y. , Misa R. , Tajduś K. , Sroka A. , Jiang Y.

|

tom Vol. 65, no. 1

147--158

EN

Coal is the main energy source in China, but its underground mining causes surface subsidence, chich seriously damages the ecological and living environments. How to calculate subsidence accurately is a core issue in evaluating mining damage. At present, the most commonly used method of calculation is the Probability Integral Method (PIM), based on a normal distribution. However, this method has limitations in thick topsoil (thickness > 100 m), in that the extent of the calculated boundary of the subsidence basin is smaller than its real extent, and this has an undoubted impact on the accurate assessment of the extent of mining damage. Therefore, this paper introduces a calculation model for surface subsidence based on a Cauchy distribution for thick topsoil conditions. This not only improves the accuracy of calculation at the subsidence basin boundary, but also provides a universal method for the calculation of surface subsidence.

3

The application of Knothe’s theory for the planning of mining exploitation under the threat of discontinuous deformation of the surface and for the prediction of ground surface movements with rising water levels in the post-mining phase

88%

Sroka A. , Hager S. , Misa R. , Tajduś K. , Dudek M.

Gospodarka Surowcami Mineralnymi

|

2021

|

tom T. 37, z. 4

199-218

EN

The article presents three German-located case studies based on stochastic methods founded by the theory proposed by Knothe and the development of the ‘Ruhrkohle method’ according to Ehrhardt and Sauer. These solutions are successfully applied to predict mining-induced ground movements. The possibility of forecasting both vertical and horizontal ground movements has been presented in the manuscript, which allowed for optimization mining projects in terms of predicted ground movements. The first example presents the extraction of the Mausegatt seam beneath the district of Moers-Kapellen in the Niederberg mine. Considering, among others, the adaption of the dynamic impact of the underground operations to the mining-induced sensitivity of surface objects, the maximum permissible rate of the face advance has been determined. The second example presents the extraction of coal panel 479 in the Johann seam located directly in the fissure zone of Recklinghausen-North. Also, in this case, the protection of motorway bridge structure (BAB A43/L225) to mining influences has been presented. The Ruhrkohle method was used as a basis for the mathematical model that was developed to calculate the maximum horizontal opening of the fissure zone and the maximum gap development rate. Part of the article is dedicated to ground uplift due to rising mine water levels. Although it is not the main factor causing mining-related damage, such movements in the rock masses should also be predicted. As the example of the Königsborn mine, liquidated by flooding, shows stochastic processes are well suited for predicting ground uplift. The only condition is the introduction of minor adjustments in the model and the use of appropriate parameters.

PL

Artykuł przedstawia trzy studia przypadków zlokalizowane w Niemczech, oparte na metodach stochastycznych, których podstawą jest teoria zaproponowana przez Knothego oraz rozwój „metody Ruhrkohlego” według Ehrhardta i Sauera. Rozwiązania te są z powodzeniem stosowane do przewidywania ruchów górotworu wywołanych wydobyciem surowców. Przedstawiono możliwość prognozowania zarówno pionowych, jak i poziomych ruchów górotworu oraz zaprezentowano możliwości optymalizacji projektów górniczych pod kątem przewidywanych ruchów górotworu. Pierwszy przykład przedstawia wydobycie pokładu Mausegatt pod okręgiem Moers-Kapellen w kopalni Niederberg. Mając na uwadze m.in. dostosowanie dynamicznego wpływu eksploatacji górniczej do wrażliwości obiektów powierzchniowych na wpływy górnicze, określono maksymalne dopuszczalne tempo posuwu przodka. Drugi przykład przedstawia wydobycie ściany 479 z pokładu Johanna leżącego bezpośrednio w strefie nieciągłości Recklinghausen-North i zastosowane zabezpieczenie konstrukcji mostowej autostrady (BAB A43/L225). Metoda Ruhrkohlego została wykorzystana w tym przypadku jako podstawa do modelu matematycznego, który został opracowany do obliczenia maksymalnego poziomego otwarcia strefy nieciągłości i maksymalnego tempa rozwoju szczeliny. Część artykułu poświęcona jest zjawisku wypiętrzania w wyniku podnoszenia się poziomu wód kopalnianych. Pomimo tego, że nie jest to główny czynnik powodujący szkody związane z górnictwem, jednak tego rodzaju ruchy również należy prognozować. Jak pokazuje przykład dawnej kopalni Königsborn, procesy stochastyczne dobrze nadają się do przewidywania wypiętrzenia gruntu, pod warunkiem wprowadzenia niewielkich korekt w modelu i zastosowania odpowiednich parametrów.

4

Effect of the entire coal basin flooding on the land surface deformation

75%

Tajduś K. , Sroka A. , Dudek M. , Misa R. , Hager S. , Rusek J.

Archives of Mining Sciences

|

2023

|

tom Vol. 68, no. 3

375--392

EN

This paper presents one of the environmental problems occurring during underground mine closures: according to the underground coal mine closure programme in Germany, the behaviour of the land surface caused by flooding of the entire planned mining area – the Ruhr District – had to be addressed. It was highlighted that water drainage would need to be continuous; otherwise, water levels would rise again in the mining areas, resulting in flooding of currently highly urbanised zones. Based on the variant analysis, it was concluded that the expected uniform ground movements caused by the planned rise in the mining water levels (comprising a part of two concepts – flooding up to the level of –500 m a.s.l. and −600 m a.s.l.), in the RAG Aktiengesellschaft mines, will not result in new mining damage to traditional buildings. The analysis included calculations of the maximum land surface uplift and the most unfavourable deformation factor values on the land surface, important from the point of view of buildings and structures: tilt T, compressive strain ε– and tensile strain ε+. The impact of flooding on potential, discontinuous land surface deformation was also analysed.