CHARACTERISTICS OF FAULT DISTURBANCES OF DOG HEADINGS IN COAL MINE OF THE UPPER SILESIAN COAL BASIN (POLAND)

Dog headings are defined as underground headings with a small cross-section in relation to their length. In the Polish (underground) coal mines, the cross-section of headings does not usually exceed 5.5 m in width and 3.8 m in height, while their length may reach even up to several kilometres. The general purpose of headings is to make possible the development of a deposit or its part containing coal seams that are to be exploited. The preparatory headings, on the other hand, are aimed at preparing the longwall for exploitation. The construction of these headings is a significant element in the investment process both in the case of newly established coal mines, as well as the existing plants in which parts of deposits at increasing depths are being developed. It may be generally assumed that in a given coal mine, each year at least several development headings and several to ten-odd preparatory headings are constructed. As the experience and scientific literature shows, such investments in the mining industry are burdened with high risk and uncertainty level resulting from the geological and mining conditions of the deposit as well as from economic conditions (political and economic decisions as well as the instability of the raw materials market). As geological and mining factors of the most significant importance with regard to performance of mining works, including driving headings tectonic disturbances (faults) should be considered. Accurate recognition of them in economic terms shall allow to estimate precisely expenditure of the planned investment project. While incorrect identification of the disturbances throughout a coal mine may even lead to its closure, what had earlier happened in the Polish mining. The paper, due to heading fault indicator, provides the characteristics of fault disturbances intensity when preparatory headings (galleries) are being driven. The research was conducted in the headings developed between the years: 2009 - 2014 in one of the Upper Silesian Coal Basin. The analysis took into account also differences in fault disturbances intensity determined in the design and as-built phase.