Assessment of Long-Term Strength of Rocks

Abstract

In relation to extraction of coal seams at significant depths, the issue of protection of safety equipment against pressure exerted by rock becomes very important. In many surveys of the effects of pressure exerted by rock it was demonstrated that the intensity of stress around the mine works increases the greater the depth of the mine works. However, surveys of technological mine works have shown that the level of deformation of the mine bracing varies in various types of rock at identical depths and no precise rule was established between the increase in pressure exerted by rock and the increasing depth of the mine works.