Identifying rational locations for field mine workings in the zone influenced by mined-out space during repeated mining of pillars

Purpose. The research aims to study the influence of bearing pressure from the barrier pillar on the field drift in order to determine the rational locations for placing field mine workings in the zone influenced by repeated mining at the Zhomart Mine of the Zhaman-Aybat field. Methods. Research includes an analysis of the results of mine studies conducted on the basis of instrumental measurements of actual parameters of the mining system structural elements, processing of multi-year statistical data on monitoring of the rock mass state, as well as modeling using Rocscience software to determine the stress-strain state of the rock mass. The actual physical-mechanical properties of the ores and host rocks of the Zhaman-Aybat field are used for modeling. Findings. The research makes it possible to determine the parameters of the field conveyor drift rational location relative to the protective pillar and the mined-out space. It is substantiated that the field conveyor drift should be designed not less than -30 m deeper than the bottom of the mined-out deposit 4-1 and at a distance of -70 m from the protective pillar boundary. The maximum stresses σmax acting on the contour of the field conveyor drift when it is located at different points are calculated. Originality. The dependence of the change in maximum stresses acting on the contour of the field conveyor drift on its location relative to the protective pillar has been found, which makes it possible the rock mass geomechanical state to be assessed in the form of a model. Practical implications. The mine surveys and numerical experimental studies have provided a new solution to an important scientific problem related to predicting the geomechanical state of the rock mass and ensuring the stability of mine workings adjacent to the mined-out space. The research results can be used in designing repeated mining operations and predicting the geo-mechanical state of the rock mass in order to ensure safe mining operations when driving preparatory workings.