Impact of underground mining to slope deformation genesis at Doubrava Ujala

Abstract

The study deals with the evaluation of possible impact of undermining on a slope deformation Doubrava Ujala nearby the city of Karviná in the north-east of the Czech Republic. Undermining is a phenomenon caused by underground mining of black coal in the active Karviná part of the Ostrava-Karviná District. It is on the boundary of the working districts Karviná – Mines I and Poruba, which are operated by the Karviná Mine. In order to assess the possible impact, isocatabase maps in different time sections were used documenting the chronology of the subsidence trough formation and next, ground deformation parameters. The activity of slope movement was registered by means of zone extensometry on the surface and in the depth by means of precise inclinometry measuring. Apart from the impact of undermining, the effects of climatic conditions were taken into consideration, correlating the movement size with precipitation depth in the nearest rainfall gauging stations. As for the mechanism of undermining impact there is an apparent influence of additional stress from undermining caused by elongation of the ground surface, which is evidenced by the position of the slope deformation in the convex part of the subsidence trough slope. All the above mentioned factors influence the stability conditions of the slope deformation.