Post-failure fatigue behaviour of intact sandstone from burst prone coal mine in Ostrava-Karvina Coalfield

Abstract

In the literature, mostly, pre-failure behaviour of the intact rock in static and rarely in cyclic loading is reported. In various earlier publications on the subject by the authors, pre-failure fatigue behaviour of intact rock is discussed. The post-failure behaviour of the intact rock in the laboratory is still a topic of hard discussion and of debate. Many researcher's of the opinion that post-failure behaviour of the intact rock is not of that rock under testing but it is simply of servo-controlled testing machines. However, in the present paper, post-failure fatigue behaviour of intact sandstone rock obtained from the rock burst prone coal mines in Ostrava-Karvina region in the Czech Republic subjected to uni-axial cyclical loading is discussed. From the presented results, the importance of post-failure behaviour in mine pillar and support design is emphasized. This study has practical significance to the behaviour of rock and rock masses within the excavation systems subjected to dynamic cyclic loads, since tested rocks were from the rock burst prone coal mines from the Ostrava-Karvina Coal Basin in the Czech Republic.