One of the most reliable methods for assessing the physical and mechanical properties of rocks as a result of their destruction are laboratory tests using hard or servo-driven test presses. They allow to obtain reliable information about changes in these properties beyond the limit of compressive strength. The results of laboratory tests of rich sulfide ore samples are presented, which made it possible to obtain graphs of their extreme deformation. Both monolithic samples and samples with stress concentrators in the form of circular holes with a diameter of 3, 5 and 10 mm were tested. It was revealed that during the destruction of the samples, the modules of elasticity and deformation decrease by 1.5-2 times, and in the zone of residual strength – by 5-7 times.
About 30 % of the mountain weight extracted on rubble the enterprises, at explode and the subsequent mechanical crushing, the fraction less makes than5 mm(elimination) which practically does not find selling and litters an environment. The output of elimination is influenced essentially with detonation characteristics explosives.
The article studies dependences of rock strengths on the time of their stressing basing on the thermal-kinetic theory of strength. The main task of the research was to calculate thermo-kinetic features of rocks and, taking into account cleavage data, to build up calculation dependences and compare them with experimental results. As the result, indices of dynamic tensile (pull) and shear strengths have been received, which are necessary for subsequent calculation of parameters of drilling and blasting operations.
