Gob-side entry retaining method reserving shed legs for filling

Abstract

The invention discloses a gob-side entry retaining method reserving shed legs for filling and aims to solve the technical problem that when the original mining roadway adopts a U-shaped shed support to perform the gob-side entry retaining, the U-shaped shed support is unstable due to the dismantled legs of the U-shaped shed, so that the U-shaped shed cannot provide stable support for a roof and even causes the failure of the entry retaining. The method comprises the following steps: firstly, reserving the legs of the U-shaped shed during the process of advance working slope tearing and gap forming; then, directly reserving the legs of the U-shaped shed in a pre-filled area for filling during the follow-up processes of manually erecting a formwork and filling; finally, forming an integrated bearing body composed of the legs of the U-shaped shed and a filling wall body to provide stable support for the roof. Meanwhile, the strength of the filling wall body is improved; the filling wall body is prevented from slipping; the gob-side entry retaining can be performed smoothly.

Description

technical field [0001] The invention relates to a method for retaining a gob-side entry in a coal mine, in particular to a method for retaining a gob-side entry in a coal mine supported by a U-shaped shed. Background technique [0002] Gob-side retaining is a method of retaining the goaf in the previous section along the edge of the goaf behind the coal mining face, using methods such as pillar support, masonry gangue belts, and filling concrete to keep the goaf in the previous section as the next step. The mining roadway in the first section will continue to be used, and the mining roadway support technology for protecting coal pillars between sections will be cancelled. The separation wall between the goaf and the mining roadway constructed by filling method is called the filling wall. According to the relative positional relationship between the filling wall and the mining roadway before mining, the gob-side entry retention can be divided into in-situ entry retention and ...

AI Technical Summary

Problems solved by technology

However, for the mining roadway supported by U-shaped shed as the original support, the semi-in-situ gob-side entry retaining has the following two problems: 1. The U-shape shed structure is unstable due to the removal of the shed legs at the advanced working face

In order to prevent the shearer from cutting the U-shaped shed legs during the coal cutting process, it is necessary to remove the U-shaped shed back mining side shed legs in advance of the working face, which not only increases the process, but also affects the advancing speed of the working face; more importantly What is remarkable is that the supporting structure after the removal of the shed legs becomes an unstable structure with unilateral support of the non-recovery side shed legs, which greatly reduces the bearing capacity of the roof of the roadway, and the key to the success of the roadway retention lies in the effective high Intensity control, insufficient bearing capacity of the U-shaped shed will lead to the separation layer damage of the regional roof before filling, affect the stability of the retained entry, and even cause the failure of the retained entry

2. The shoulder of the mining side of the U-shaped shed is not filled tightly

Irregular filling spaces are formed between the shoulder of the U-shaped shed, the roof of the area to be filled, and the filling formwork on the non-recovery side, resulting in incomplete filling and reduced strength of the filling wall. Under the action of lateral pressure and roof pressure, the filling wall deforms It is very easy to develop into the area where the filling is not dense, resulting in the destruction of the filling wall and difficult maintenance of the roadway

[0004] There is no effective solution at home and abroad for the above-mentioned problems existing in the semi-in-situ gobside entry retention technology that uses U-shaped shed support in the original mining roadway

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