Gob-side entry retaining system and method for cementing gangue in gob-side goaf into wall

Abstract

The invention provides a gob-side entry retaining system for cementing gangue in a gob-side goaf into a wall. A first hydraulic jack is hinged on a hydraulic support tail beam at the end of a workingface; one end, close to the goaf, of the first hydraulic jack is connected with a first gangue baffle; a second hydraulic jack is hinged to the side, close to the goaf, of an entry retaining support;one end, close to the goaf, of the second hydraulic jack is connected with a second gangue baffle; the second gangue baffle is positioned behind the first gangue baffle; the second gangue baffle abutsagainst the first gangue baffle and encloses an entry retaining operation area; and a grouting pump station injects a high-water filling material into the entry retaining operation area through a grouting pipe. According to the gob-side entry retaining system for cementing the gangue in the gob-side goaf into the wall, collapsed gangue in the goaf can be fully utilized, the working face can be immediately followed, the entry retaining by cementing into the wall is finished, the goaf and a gob-side roadway can be isolated all the time, the cost is low, and the adaptability is high. The invention also provides a gob-side entry retaining method for cementing the gangue in the gob-side goaf into the wall.

Description

technical field [0001] The invention belongs to the technical field of coal mine roadway support, and in particular relates to a gobside roadway retention system and method in which gangue is cemented into a wall in a goaf beside a roadway. Background technique [0002] In recent years, coal pillarless mining technology has been widely used in coal mine production activities, among which automatic roadway formation by roof cutting and pressure relief, and roadside filling and gobside retention are the two main methods of coal pillarless mining. Roadside filling is divided into high water material roadside filling and concrete roadside filling. [0003] However, roadside filling with high-water materials, concrete roadside filling, and automatic roadway formation with roof cutting and pressure relief all have defects. Specifically, 1) Filling gobside entry retention next to concrete roadway has the following disadvantages: the concrete grout is thick, the concrete grout is e...

AI Technical Summary

Problems solved by technology

[0003] However, roadside filling of high-water materials, concrete roadside filling, and automatic roadway formation with roof cutting and pressure relief all have defects.

Specifically, 1) Filling gobside entry retention next to concrete roadway has the following disadvantages: the concrete grout is thick, the concrete grout is easy to separate water during the solidification process, the concrete wall is difficult to connect to the top, and the sealing effect of the goaf is poor. The concrete wall cannot actively support the roof , passive bearing, which is not conducive to the deformation control of the surrounding rock of the roadway; the condensate does not give way, and the wall is prone to irreversible deformation and damage. When the roof condition is poor, it is easy to cause the roof to be cut off along the edge of the wall in the roadway; Although the gob-side retaining method has many advantages such as simple process, fast resistance increase speed of roadside support body, large support resistance, good plasticity, good filling body connection effect, good isolation effect from gob area, and wide application conditions, etc., However, it has a common feature with concrete gob-side entry retention. It needs to construct the filling body beside the entry, and needs to increase the input of more materials. For mines with complex geological conditions, poor coal quality, and poor mine efficiency, they are often reluctant to increase 3) The method of roof cutting and pressure relief for automatic roadway formation and goaf retention has the following disadvantages: the process is cumbersome; the passive gangue support material is seriously bent and deformed and cannot be recycled, and the material and labor investment is large; laying air duct cloth and hanging net spraying Slurry and other means are unreliable, coal left in the goaf has the risk of spontaneous combustion, and gas accumulated in the goaf is likely to flow into the roadway and cause gas to exceed the limit. It is not suitable for high-gas mines and mines where coal seams are prone to spontaneous combustion

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