Tsikra A. Development of ways to increase the load-bearing capacity of roof bolts in the arch-bolting maintaining workings of unstable rocks

The thesis is devoted to developing ways to improve the load-bearing capacity of roof bolts in the arch-bolting maintaining workings of unstable rocks on the basis of obtained regularities of the changes of load-bearing capacity of bolts considering boreholes rifling and manifestations of rock pressure in deep mines. Object of research: processes of a deforming of system "support- massif" in the maintaining development workings arch-bolting supports. Subject of research: ways to improve the load-bearing capacity of roof bolts as element of arch-bolting maintaining in the difficult geological conditions. The operation purpose: development of ways to increase the load-bearing capacity of roof bolts in the arch-bolting maintaining workings of unstable rocks. Development of ways to increase the load-bearing capacity of roof bolts in the arch-bolting maintaining workings of unstable rocks. Methods of research: the analysis and generalization information, laboratory and mine research, mathematical modelling of geomechanical processes, engineering designing, the technical and economic analysis. Investigated the mechanism of destruction of the contact bond area "bolt-resin-rock", which begins in places of the raised fracturing of a massif and is passed round in a wave mode along an axis of the rod of an bolt, and at its moving to the hole to 70 mm remain 70-90 % of its original load-bearing capacity. It is installed, that strength of attaching directly proportional strengths of rocks and to quantity of resin protrusions and inversely proportional to magnitude of moving of an anchor in the hole. In the unstable rocks application for bolting of purposefully altered boreholes rifling increases the load-bearing capacity of bolts, the maximum principal stresses in a bolted section of the rock strata is increased by 61 %, the zone of inelastic deformation around preparatory mine working is reduced by 26 %. Methods and equipment for boreholes rifling and nomogram for determining the number of resin protrusions have been developed. Experimental-industrial testing of the new method arch-bolting maintaining workings showed its effectiveness. When the roof lamination is at 70-80 mm bolts retain the load-bearing capacity and have greater suppleness, thus reducing the load on the arched roof supports and roof displacement by 42-45 %. Ways to incorporate when developing 2 and 3 west LW in seam l4 on Zasyadko mine. The author's participation in the actual economic effect of implementing "The recommendations on the sustainability of ventilation passway of "gas horizon" for 16 west LW in seam m3 " and advanced way to arch-bolting development was estimated as 2037,5 thousands of UAH. Methodical and practical aspects of the dissertation can be used: research institutes, the mines and the design organizations, which are engaged in expedients and resorts of effective and safety maintenance of developments workings.