Anchor bolt of rock massif in coal mines to decrease soil rock heaving of the workings

Abstract

During the maintenance of workings, the effects of soil rock heaving, caused by plastic deformation and extrusion into the excavation cavity under the action of the rock pressure, are usually eliminated. The identified patterns of change in the stress-strain state of coal-rock massifs (displacements, stresses, cracking zones), depending on the main mining-geological and mining-technical factors will allow to establish the optimal parameters of soil anchoring, technological schemes for decreasing soil rock heaving of mine workings to increase the stability of preparatory mine workings have been developed. The development and improvement of existing technologies of effective and safe stiffening of near-soil rocks at conducting mine workings on flat and inclined coal seams were substantiated. The modelling of the SSS shows that both side-rock and ground deformations are predominantly influenced by side anchorage which results in reduction of the effective deformations in the rocks surrounding the working and in a decrease of gas release from the coal massif. It is established that the deformations and stresses both side and in-soil rocks in the excavation are influenced by side anchors rather than near-soil ones.