Method for supporting tunnel roof below mined-out area

Abstract

The invention relates to a method for supporting a tunnel roof below a mined-out area. In the method, steel belt combination hydraulic power expansion anchor rods are used for supporting the tunnel roof below the mined-out area. The method comprises the following steps of: erecting temporary supports for the tunnel roof dug out below the mined-out area and at both sides of the tunnel roof, laying a metal net and a steel belt on the roof so as to lead the steel belt to push down the metal net, using a single prop to support the steel belt, and punching holes and drilling holes on the tunnel roof through orifices of the steel belt; then sequentially placing the hydraulic power expansion anchor rods in boreholes, leading the steel belt to be clung to a top plate by a tray, injecting high pressure water with the pressure of 20 to 22MPa into the hydraulic power expansion anchor rods one by one, wherein the liquid injection time for each steel belt combination hydraulic power expansion anchor rod is not less than 2min; and repeating the steps till finishing the support of the tunnel roof below the mined-out area. The method solves the difficult problem that a traditional resin anchoring anchor rod can not be anchored in the mined-out area and can not effectively support the top plate of the tunnel roof below the mined-out area at a very short distance; and the method has simple process and is convenient to operate.

Description

technical field [0001] The invention relates to a method for supporting the roof of the roadway below the goaf, especially suitable for the roof support of the roadway below the goaf when coal seam groups are mined at very close distances, and can also be applied to the roof support of the roadway under the layered mining of thick coal seams support. Background technique [0002] The occurrence and mining of short-distance coal seams account for a large proportion in my country, and most mining areas have the problem of short-distance coal seam group mining. With the continuous increase of coal mining intensity, especially the rapid development of high-yield and high-efficiency technologies in recent years, the coal seams with good mining conditions in most mining areas have been nearly exhausted within a short service life, prompting the mining of short-distance coal seams to rapidly develop. Enter people's field of vision and attract great attention. For coal seam group ...

AI Technical Summary

Problems solved by technology

Once the separation layer of the roof of the roadway is loose, since the pressure that the metal shed beam can bear is limited, it cannot resist the energy released by the deformation and damage caused by the large separation layer of the surrounding rock of the roadway, which will eventually lead to further separation of the roof. layers, loosening, causing roof fall accidents