The study concentrates on analysis of heterogeneous rock mass deformations in the final years of underground coal extraction and during the revitalisation period after the end of mining. The research has been carried out in the Walbrzych Coal Basin where underground mining ceased at the end of the 20th Century. In the paper results of initial stages of ground deformation studies on a fragment of the Walbrzych mining grounds concerning analysis of benchmark height changes in a selected levelling line has been described. The results indicate ground subsidence in the period immediately after end of coal extraction and change to a steady uplift of the ground a few years later (2000-2008). Abnormal changes of heights in tectonic fault zones have also been observed. These could be related to heterogeneous rock mass reaction during the revitalisation period., Jan Blachowski, Stefan Cacoń and Wojciech Milczarek., and Obsahuje bibliografii
Underground mining activity in the region of the Upper Silesian Coal Basin (USCB) results in ground displacements scattered on a large area. Both the locations and the velocities of the displacements depend on many factors, such as the current location of the mining front, the mining depth and system, as well as geological conditions. Although SAR interferometry techniques allow the monitoring of such ground displacements, in a regional scale (as is the case of the USCB) SAR images must be appropriately processed (from a number of frames and swaths), and this is the problem addressed in this article. The implementation of algorithms for analyzing time series allows observations of displacements in both time and space. The authors also analyze the influence of mining operations on the road infrastructure and mining waste heaps located in the area and investigate the potential for the monitoring of secondary influence (due to induced seismic tremors). As a result of these investigations, the article presents the quality of the InSAR-SBAS data and the potential for their employment in the measurements.
Underground mining hard coal in the area of Walbrzych ended in the late 90-ties of the last Century. Its effects on the state of heterogeneous rock mass (complicated geology and tectonics) is still evident and not known precisely. Analysis of levelling measurement results carried out after the end of mining activity (1997-2008) for part of the former “Thorez” mine indicates increased rock mass surface activity in tectonic zones. With the aim to continue monitoring of the rock mass surface movements on the area of former mining grounds a research satellite GPS network (7 points) has been established and supplemented with new precise levelling lines linked to the existing 2nd class levelling network. Location of these points takes into consideration, among other things geology and tectonics of the Walbrzych Basin and areas of underground mining activity. In this paper work on the design and construction of the research satellite GPS and levelling networks has been described and the first measurement campaign carried out in September 2009 has been presented. Its results will form foundation for complex studies of rock mass surface in the next measurement epochs., Jan Blachowski, Wojciech Milczarek and Stefan Cacoń., and Obsahuje bibliografii