Blasting effect evaluation method when blasting of coal pillar at lower portion of coal seam roof

Abstract

The present invention discloses a blasting effect evaluation method when blasting of a coal pillar at the lower portion of a coal seam roof. The method comprises the following steps: S001: prior to the blasting of a coal pillar, arranging a plurality of tunnel boreholes in a tunnel at the lower portion of the coal pillar, and correspondingly arranging one stressometer in each tunnel borehole; S002: performing blasting of the coal pillar; S003: after the blasting of the coal pillar, recording the current value of each stressometer, and calculating and obtain the actual value changing range of each stressometer; S004: selecting the stressometer Gm as a reference, and setting the preset value changing range of the stressometer Gm as f; and S005: if Fm>=f, determining that the destroy degree of the coal pillar accords with an entire blasting standard, and if Fm<f, determining that the destroy degree of the coal pillar accords with a partial blasting standard. The blasting effect evaluation method can accurately measure the blasting degree of the coal pillar and the coal seam roof collapsing condition and improve the safety of the work surface when the work surface passes through the area where the coal pillar is located.

Description

technical field [0001] The invention relates to the technical field of coal mining, in particular to a blasting effect evaluation method when blasting a coal pillar below a coal seam roof. Background technique [0002] At present, the known methods for evaluating the effect of underground blasting of residual coal pillars on the roof of shallow coal seams are relatively simple, and the roof movement is only indirectly judged by monitoring the mine pressure of the working face and the separation of the roadway. However, the roof movement after blasting is a dynamic change process of overlying rock damage. The appearance of mine pressure and the layer separation of the roadway roof lag behind the overlying rock damage, and the damage law and degree of damage after blasting cannot be directly measured by general roof monitoring. Therefore, it is impossible to accurately test its blasting control effect. Contents of the invention [0003] The object of the present invention i...

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Problems solved by technology

[0002] At present, the known methods for evaluating the effect of underground blasting of residual coal pillars on the roof of shallow coal seams are relatively simple, and the roof movement is only indirectly judged by monitoring the mine pressure of the working face and the separation of the roadway.

However, the roof movement after blasting is a dynamic change process of overlying rock damage. The appearance of mine pressure and the layer separation of the roadway roof lag behind the overlying rock damage, and the damage law and degree of damage after blasting cannot be directly measured by general roof monitoring. Analysis and judgment, so it is impossible to accurately test its blasting control effect

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