Substantination of hydromechanical parameters of water regulation using mine pillars during mines closure

Abstract

Purpose. Substantiation of hydromechanical parameters that make it possible to control the safe ratio of hydrodynamic levels in a mine shaft and a rock mass when closing mines using submersible pumps. Research methodology. An experimental-analytical method was used, which consists in the formation and analysis of data from field tests of fractured porosity, permeability and the position of groundwater levels in hard sandstones around mine shafts with concrete support. Research results. It has been established that the hydromechanical state around a mine shaft in stable water-bearing rocks is characterized by the development of mutually competing processes of nonlinear decrease in the permeability of the loaded rock contour and hydrogeomechanical unloading of structural elements of water-bearing rocks and filter attachment. The values of the hydrogeomechanical unloading of the shaft attachment in the range of 0.054 - 6.125105 Pa are close to the tensile strength limit of the "concrete-water-bearing rock" contact, which indicates the danger of its collapse. Scientific novelty. The problem of combining the elastic viscometric load of the rock mass attachment and the hydrodynamic planar-radial flow to the wellbore is solved, where the hydrogeomechanical state in stable water-bearing rocks is characterized by the development of mutually competing processes of nonlinear decrease in the permeability of the loaded rock contour and hydrostatic unloading of structural elements of the water-bearing rocks and filters. Practical value. The obtained solutions and their analysis explain the discrepancy between the calculated (standard) loads on the fastening, which is known from practical experience, and actually measurable values, and also have significant practical significance. The established fact of the approximation of the value of hydrogeomechanical unloading of the stovol attachment to the tensile strength of the contact "concrete - water-bearing rock" is dubious and requires a decrease in the hydrodynamic deflection to the mine stovol when controlling the process of flooding with submersible pumps.