Roadside coal body impact risk assessment method based on borehole stress distribution

Abstract

The invention discloses a roadway side coal body impact risk assessment method based on borehole stress distribution, and belongs to the field of coal mine safety mining engineering. Monitoring the mass point vibration peak velocity of the roadway surrounding rock caused by the mine earthquake by using a micro-earthquake system, and fitting to obtain a vibration wave propagation attenuation law curve; according to the mine earthquake source position monitored and positioned by the micro-earthquake system, the mass point vibration peak velocity at the earthquake source is obtained by using the vibration wave propagation attenuation law curve; calculating a mass point vibration peak velocity caused by the vibration wave propagating from the seismic source to the elastic nuclear region, and obtaining a mine vibration load level of the elastic nuclear region; according to the relation between the impact critical stress and the coal body strength and the coal seam strength, the induced impact critical static load stress of the roadway side coal body in the area where the drill hole is located is calculated; calculating an elastic energy nuclear resistance line critical value of the roadway side coal body; and judging the impact danger level of the roadway side coal body near the drill hole. Physical indexes are clear, evaluation results can be quantified, operability is high, and anti-impact pressure relief work can be guided according to impact risk evaluation results.

Description

technical field [0001] The invention relates to a method for assessing the impact risk of a roadway side coal mass based on the stress distribution of boreholes, and belongs to the technical field of coal mine safety mining engineering. Background technique [0002] Rock burst is a serious mine dynamic disaster, and its occurrence is mainly related to the high stress concentration in the coal seam. The pressure relief of large-diameter boreholes in coal seams is one of the main technical means to prevent rock bursts. The deep transfer of the coal body releases the elastic energy accumulated in the coal body and reduces the dangerous level of rock burst. During the construction of large-diameter boreholes, by monitoring the working state of the drilling rig and drill pipe, the stress state at different depths of the borehole can be inverted, and then the stress distribution state of the borehole can be used to determine the dangerous state of coal impact near the borehole. ...

AI Technical Summary

Problems solved by technology

Among them, the impact risk assessment effect of the drilling cuttings method is better, but the special construction of drilling cuttings holes is time-consuming and laborious, and there are dangers in the construction; the shock wave CT inversion method can only obtain a wide range of stress field characteristics and impact hazards, and cannot Accurately assess the impact risk of specific parts of coal and rock mass, and the seismic wave CT method requires a long period of accumulation of mine seismic data, and cannot perform impact risk assessment in each target area in time; electromagnetic radiation method and geoacoustic method can only The indirect assessment of the stress concentration state and impact risk level of a large-scale coal seam cannot accurately assess the impact risk of a specific location of the coal seam

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