Andrzej Leśniak

and 2 more

In rock mass disturbed by mining activity, distortions in the stress balance may lead to seismic energy being emitted in rejuvenated seismogenic structures. One way of increasing the imaging resolution of these seismically active structures is through relocation, which itself can be achieved using the cloud collapsing method. This method partially eliminates perturbations in the location of seismic energy sources concerning the actual positions of these sources. It enables phenomena to be grouped into spatially ordered structures that can correspond to actual tectonic structures, such as fractures, fissures or faults. The article presents results of applying the collapsing method in mining seismology using cloud of tremors recorded during mining activity at one of the coalfaces in the Bobrek hard coal mine. The relocation procedure was applied to all the foci of tremors recorded during mining activity on face 3/503 between 04.2009 and 07.2010. In the relocated point cloud two types of linear structure responsible for generating tremors are distinguished: structures directly related to mining activity and structures associated with local tectonics. The location of the separated structures of the first type corresponds to the range of coalface 3/503 and the shafts delimiting earlier mined seams 507 and 509 located below. The isolated structures of the second type, with almost vertical orientation, are associated with existing zones of discontinuity that become seismically active as a result of mining activity. The identified structures lie near the biggest tremors recorded, which is evidence that these structures may correspond to real discontinuity zones.