Study on Optimization of Roadway Position in Pre-mining Upper Layered Concave–Convex Coal Body

Abstract

Reasonable roadway layout is of great significance for mine safety and high efficiency production. The “concave–convex” coal body formed by pre-mining upper strip mining in Jinqiao Coal Mine, in order to recover the remaining coal resources, the selection of reasonable roadway location has become the first problem to be solved. In this paper, by means of theoretical calculation and numerical simulation, the failure range of plastic zone of floor and stress distribution law after upper layer mining are studied. At the same time, the stress distribution and displacement of roadway with different coal pillar width are analyzed. The results show that: After the upper layer mining, the failure depth of the floor is 6.9 m, the “ voussoir beam” is formed at the edge of the goaf, the stress distribution in the coal pillar presents “double hump”, the roadway is arranged in the middle of the coal pillar, the stress concentration is the smallest, and the deformation of the roadway is the smallest. Therefore, the optimum layout position of the mining roadway is determined. Through the field monitoring, the roadway deformation within the allowable range, the desired purpose has been achieved. It can provide theoretical support for the selection of roadway location under similar conditions.