Causes analysis of occurrence of the terrain surface discontinuous deformations of a linear type

In the article some area located in the mining terrain of hard coal mine in Poland has been analysed. In this area the discontinuous deformations of a linear type, for example faults and ground steps have been occurred. They had the substantial dimensions and appeared near or under the residential buildings. That's why they are so dangerous. In this paper the causes of their occurrence have been analysed. Probably a main reason of their creation is an intensive, underground mining exploitation which in two hard coal seams has been carried out. These seams were located at a relatively small depth, inclined at a significant angle, exploited by the use of a longwall system with a roof rocks cave-in and had a considerable thickness. All of these things contributed to accumulation of the adverse stresses concentrated in one area. Release of stresses caused by an extraction of hard coal contributed to the formation of numerous faults.