Hard top plate waterflooding pressure relief treatment method

Abstract

The invention discloses a hard top plate waterflooding pressure relief treatment method. The method comprises the following steps of S1, according to a stratum histogram, through combination with a rock mechanical property test, carrying out preliminary analysis on positions and development case of top plate separation fractures, S2, when cutting depth at an open-off cut on the work surface is in a range of 13-17m, drilling a row of holes on the top plate at a certain angle along a work surface advance direction, and observing top plate rock stratum crack development case by a borehole camera, S3, further detecting top board crack development case by a double-head water-plugging device detection system, S4, determining a top plate rock stratum crack development range and depth according to the results of the above three steps, and pouring high pressure water into the cracks by a high pressure water pump so that hard top plate integrity is broken and rock strength is reduced, and S5, after top plate pressure is released, sequentially pushing the work surface and repeating the above processes until work surface exploitation is finished. The method can realize accurate positioning of a pre-cracked top plate position and full utilization of a top plate separation layer crack space and is frees of artificial arrangement of a pre-cracking space.

Description

technical field [0001] The invention belongs to the technical field of coal mine mining safety, relates to a coal mine stope surrounding rock control technology, in particular to a water injection and pressure relief treatment method for a hard roof. Background technique [0002] In my country, the coal seam belonging to the hard roof accounts for about one-third, and is distributed in more than 50% of the mining areas. The overhang of the working face with a hard roof is large, and the mining pressure is concentrated in time and intensity, which poses a great threat to the mining face, and may induce large structural mutations and instability, resulting in rock burst and other related disasters, which pose a threat to the safe mining of coal seams. Great threat. [0003] Under the condition of a hard roof, it will only collapse when the working face advances 30-40m or more from the cut hole. This kind of collapse is sudden and unpredictable, which is extremely destructive ...

AI Technical Summary

Problems solved by technology

[0005] It is not difficult to see that the above two types of processing methods all have the following deficiencies: 1. The position of the pre-cracked roof is artificially selected. There is still a risk of impact during the face-on advance

2. Manually open a pre-cracking space by replacing the drill bit at the position to be cracked, and then achieve the purpose of pressure relief through high-pressure water injection. This kind of treatment process is cumbersome, the workload is heavy, the practicability is poor, and there is a big gap with the expected effect

Images