METHOD FOR DETERMINING THE STRESS STATE OF ROCK FORMATIONS Russian patent published in 2022 - IPC E21C39/00 

FIELD: mining industry.

SUBSTANCE: invention relates to the mining industry, in particular to methods for determining the stress state of rock formations. During sink working, tunneling holes are drilled, charged and blown up. The method includes drilling a hole, determining the initial and final diameter of the hole. Moreover, the final diameter of the hole and the maximum size of a piece of rock in the hole are determined after blowing up the explosive. The magnitude of the stress state of the mountain range is determined from the expression: , where σ_compr is the compressive strength of the rock, Pa; D is the detonation velocity of the explosive, m/s; ρ_B is the loading density, kg/m³; d_c is the initial diameter of the hole equal to the explosive charge, m; c is the velocity of the longitudinal wave in the rock, m/s; d_k is the maximum size of a piece of rock in the hole after the explosion; µ is the coefficient of friction between separate parts in the array; ϑ is Poisson’s ratio of the rock; Dc is the final diameter of the hole, m; F is the fracturing index; d_e is the size of a separate part in the array, m; π = 3.14.

EFFECT: operational determination of the stress state of rock formations during excavation in rocks of different strength and at different values of rock pressure.

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