Rock bursts during reduction of coal production in Ostrava-Karvina coalfield

Coal production in Ostrava-Karvina coalfield (hereafter OKC) is connected with occurrence of rock bursts. These rock bursts became a serious threat both in view of their consequences and in view of their frequency during seventies and eighties of the preceding century during which the biggest annual coal outputs in history of coalfield were achieved, i.e. 24 million t/a. It was expected, therefore, that the wind-up of coal mining, which occurred during nineties and during which coal production was gradually reduced up to annual output of about 14 million t/a, would be manifested by a reduction of rock burst risk and thus by diminishing of frequency of rock burst events. However, practical results have demonstrated that the risk of rock bursts in OKC is continuously very actual and that the natural and mining technical conditions of coalfield participate in a decisive manner in this problem.