Development of roof bolting use in Polish coal mines

In the paper, after short historical outline, a development of roof bolting use in Polish coal mines on the span of last twenty years was presented. Two characteristic examples of use were given. First of them is related to the solution, which found the widest use in mines. It consists in replacement of abutment at longwall and entry crossing with bolts. Second example concerns the use of independent roof bolting. For both examples, the geological conditions were described, as well as the applied patterns of bolting and the principles of support and mine working stability control. The realized review of development of roof bolting enables to present series of advantages resulting from the use of roof bolting. The use of independent roof bolting gives the largest efficiency effects. The calculations conducted for definite workings proved that the reduction of costs between 24 and 57% may be achieved in relation to arch support. Simultaneously, the fact attracts attention, that the total length of workings executed with independent roof bolting for last twenty years makes only 15% of stone coal workings total length realized in Polish coal mining on the span of one year only.