Determination of physical and mechanical properties of rocks using anti-burst destress measures

Abstract

Rock bursts are traditionally one of the main problems in the mining industry. In recent years, with an increase in the depth of mineral mining, this problem has become more relevant. To prevent dynamic events induced by rock pressure, various combat methods have been developed at the present time. Among them, the most common approach to prevent rock bursts is destressing by creating local zones of yielding in rocks. This is possible with drilling a series of destress wells or by inducing fractures with blasting. However, for a more accurate assessment of the effectiveness of these measures, it is also necessary to research the change in the properties of rocks during their fracture. In this study, the special model mechanical tests were carried out to determine the strength and strain characteristics of solid sulfide ore samples in the complex loading conditions. Operation of the destress wells was simulated by making holes in the samples. To model destress blasting, softening of the model samples with holes, pressed into steel shells, was performed by exposing them to an explosive pulse from a detonating cord. Lateral compression of the samples by the steel shells created the three-step stress of 15, 30 and 45 MPa in them. In the subsequent uniaxial compression tests on the servo-hydraulic press with the transverse straining control, strength limits, strain characteristics and rock bursting susceptibility of the samples were determined.