Method of Releasing the Stress of the Triangular Suspended Roof by Blasting the Island Body

Abstract

The invention discloses a method for blasting an island body to release the stress of a triangular suspended roof region. The method comprises the following blasting steps that firstly, drilling holesare distributed according to the area of the triangular suspended roof region, and the drilling holes at least comprise main drilling holes arranged in the three angular positions and the central position of the triangular suspended roof region respectively, and a plurality of adjusting drilling holes arranged in other positions in the triangular suspended roof region; secondly, carbon dioxide blasters are installed inside the main drilling holes, and the adjusting drilling holes are vacant inside to serve as free surface vacant holes; and finally, all the carbon dioxide blasters inside the main drilling holes are initiated. The method for blasting the island body to release the stress of the triangular suspended roof region is safe and reliable, is not influenced by gas accumulation in agoaf, and is particularly suitable for the application to a highly gassy mine, the blasting fragment size is not limited, construction is simple and convenient, the area of the triangular suspended roof region can be reduced effectively in time, stress concentration in the goaf is weakened or eliminated, a suspended roof in the goaf is timely stripped and collapsed, the goaf at the middle upper part is filled, and safe and smooth production of a working face is guaranteed.

Description

technical field [0001] The invention belongs to the blasting technology for underground surrounding rock construction, in particular to a method for releasing stress in a triangular suspended roof area by blasting an isolated island body. Background technique [0002] During mining at steeply inclined working faces, there are many people entering and exiting at the upper end of the return air chute, and there are many equipment arrangements. The stability and safety of the roof of the mining face, especially the return air chute, is of great importance. The instability of the roof will directly threaten the safety of personnel and equipment. . According to the existing roof control methods, the roof safety management technology is relatively mature for gently inclined and near-horizontal coal seams, but there are still many safety problems for the roof management of steeply inclined coal seam working faces. [0003] The suspended roof of the triangular area at the upper end...

AI Technical Summary

Problems solved by technology

According to the existing roof control methods, the roof safety management technology is relatively mature for gently inclined and near-horizontal coal seams, but there are still many safety problems for the roof management of steeply inclined coal seam working faces.

[0003] The suspended roof of the triangular area at the upper end of the return air trough is located in the goaf. According to the particularity of the steeply inclined roadway, due to the influence of gravity, the rocks falling in the goaf will first slide to the middle and lower part of the working face and give priority to the goaf. Filling in the middle and lower parts leads to no or little filling in the upper goaf of the working face, resulting in an empty roof in the triangular area, increased safety hazards after the suspended roof, frequent entry and exit of personnel and equipment at the end of the steeply inclined working face, and surrounding rocks in the suspended roof lead to heightened security risks

In particular, it is strictly forbidden to use explosives for goaf blasting operations, so it is extremely difficult to deal with the roof suspension of steeply inclined hard roof coal seams

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