Feasibility discrimination of upward mining in close-distance coal seam and mining influence analysis

Abstract

Upward mining can not only overcome the thorny problems of technology, economy and management, but also realize the sustainable development of mine and avoid the waste of coal resources. In order to judge the feasibility of the upward mining, this paper studies the deformation and failure characteristics and migration law of the upper 1# coal seam after the mining of the lower 3# coal seam using theoretical discrimination method and the Comsol Multiphysics numerical simulation according to the occurrence conditions of the coal seam of the Changcheng fifth coal mine. The results show that: after the mining of the 3# coal seam, the 1# coal seam is located in the upper part of fracture zone, and the integrity is not damaged; the actual interval between two coal seams is much larger than the necessary interval to meet the requirement of upward mining; with the progress of upward mining, the range of interlayer rock mass movement and deformation is increasing, but it will not affect the normal mining of the 1# coal seam. On the basis of the research results, the failure depth of floor after the mining of the 3# coal seam is calculated, which has a certain theoretical guiding significance.