MODELING THE STRESS STATE OF THE BACKFILLING MASS WITH DIFFERENT PHYSICAL AND MECHANICAL PROPERTIES

Abstract

Purpose. Analytical researches of the stress state of the backfilling stopes with different physical and mechanical properties using numerical modeling to determine possible zones of stability losses and predict their failure. Methods. Numerical modeling of the formation of stresses around a high stopes was carried out for the conditions of mining iron ore reserves in the depth intervals of 740-1040 m of the Pivdenno-Bilozerske deposit, where mining operations are actively carried out using the finite element method in the SolidWorks 2016 software package with reliable substantiation of the parameters of the developed geomechanical model. Results. Numerical simulation of the stress state of the backfilling mass are carried out at variable values of the modulus of its elasticity and the mining depth. It was found that with the existing actual physical and mechanical properties of the backfilling mass during the development of the Pivdenno-Bilozerske deposit, the danger of its failure is predicted at depths of more than 890 m. In the center of the filling array, the stress values change linearly, and at the junction of the roof with the side of the backfilled stopes – polynomial. It was found that an increase in the modulus of elasticity of the backfilling mass allows to reduce the compressive stresses only at the junction of the roof with the side of the backfilled stopes to a value of 800 MPa. Scientific novelty. With an increase in the depth of development, despite an increase in the elastic modulus of the fill, the values of stresses increase, which eliminates the need to increase it with a decrease in the mining depth it was found. Practical significance. The results obtained make it possible to correct the technology of formation of a backfilling mass in the primary stopes, taking into account the formation of stresses on its contour and, with an increase in the mining depth, to form a backfilling mass with viscoplastic properties.