A new design of support for burst-prone rock mass in underground ore mining

The article presents the basic methods of strengthening room and roadway excavations in underground ore mining. In particular, it was pointed out that the mining support is very often exposed to additional dynamic loads resulting from the mining of the deposit by means of explosives (slight) as well as from the load arising from rock mass tremors. In the article a new design of arch yielding support adapted to dynamic loads, which can be used in long-term access excavations was proposed. For this case, an exemplary spring deflection, which is located in the support foot cylinder, based on the principle of work and energy was calculated. In the case of exploitation room excavations, laboratory tensile tests of the long expansion rock bolt support, which were carried out in the rock bolting laboratory at the Department of Underground Mining AGH were presented. Load-displacement characteristics for long expansion rock bolt support with a particular indication of the elastic and plastic range were presented. In the summary, it was concluded that with the increase in the depth of exploitation, safe and efficient mining will be possible only due to the use of a support with appropriate yielding.