Research of borehole drilling parameters for determining the optimum size of granite stone blocks

Abstract

Abstract The optimal geometrical parameters of boreholes in dimension stone quarries, whose impact on granite blocks separation and splitting efficiency, are determined, taking into account the stress-deformed state of rock massif. The crack initiation process is analysed considering the flat problem of elasticity theory. Determine destruction parameters of natural stone by borehole methods using the calculations of the required distance between the boreholes in the row along the splitting line with the specified borehole diameters, and created forces of stone destruction are proposed. The optimal shape of splitting block from massif depends on the specific plane of splitting is determined. The possible directions of borehole deviation from ideal ones, their extension due to drilling and tensions in the boreholes are studied. The introduction of the borehole’s overlapping coefficient, which influences the weakening of the massif along the directed (designed) split line, is proposed to define further necessary tensions for mechanical ways of separating blocks. The equations for determining drilling operations parameters at granite blocks splitting from dimension stone quarries massifs are proposed. The coefficient of limit values of deviation angles is defined.