Method of gob-side entry retention for small coal pillars in deep mines based on pressure relief of faulty roofs in key layers below the roof

Abstract

The invention provides a gob-side entry retaining method for a small coal pillar in a deep shaft based on the pressure relief of a faulty roof in a key layer below the roof, relates to the technical field of coal mining, and improves the ventilation and support in the gob-side entry retaining of a deep mine. The steps include: determining the geological conditions of the roof, determining the blasting parameters according to the geological conditions of the roof, numerically simulating the pressure relief effect of the broken roof of the lower key layer with different thicknesses, and determining the parameters of the broken roof of the roadway; Displacement monitoring stations, anchor rods and anchor cable force monitoring stations are arranged for the surrounding rock in the surrounding rock; support parameters are revised, blasting is carried out in the roadway of gob-side entry retention, and support is carried out according to the revised support parameters. In this method, blasting is carried out on the side of the coal seam roof that is biased towards the solid coal, and the stress transmission of the key layer is cut off in the lower key layer of the pre-split coal seam roof, so that the high stress acting on the small coal pillar and the gob-side entry is transferred. Thereby improving the environment of the roadway, which is conducive to the maintenance of the roadway.

Description

technical field [0001] The invention relates to the technical field of coal mining, in particular to a pressure relief and support method for small coal pillars in deep mines and gob-side entry retention. Background technique [0002] With the depletion of shallow coal mine resources, mine mining depth is increasing year by year, coal seam occurrence conditions are becoming more and more complex, rock burst, coal and gas outburst, high temperature heat damage and other problems seriously threaten the safety of mine production, and at the same time, there is a tension in mining. It is also increasingly prominent, especially for old mines and mines with complex conditions, which seriously restricts the safe and efficient production of mines. Currently, the commonly used gob-side roadway layout has contradictions between the tension of excavation and the series ventilation of high-gas mine working faces; although the above-mentioned problems can be solved by adopting wide coal ...

AI Technical Summary

Problems solved by technology

However, the roof-cutting self-forming roadway technology requires super-strong support for the gob-side retaining roadway, which is difficult and costly, and the roadside retaining system is difficult to block the infiltration of harmful gases; Coal pillar mining technology is seriously affected by high ground pressure, so it is rarely used in deep mine mining

Images