Test and evaluation method for deep hard roof coal seam bump proneness

Abstract

The invention discloses a test and evaluation method for deep hard roof coal seam bump proneness. The method comprises the steps of: preparing standard pure coal test pieces, standard pure rock test pieces and standard coal-rock combination test pieces; calculating the residual energy release rate of the standard coal-rock combination test pieces; and evaluating the proneness of the standard coal-rock combination test pieces. The standard coal-rock combination test pieces of corresponding proportions are made according to the actual thickness of on-site hard roofs and coal bodies, and by means of a quantization process, the influence of the coal rock combination effect and the combination size effect to bump proneness is fully reflected, and the accuracy of the evaluation result is significantly enhanced. Also, the method provided by the invention takes the coal-rock combination residual energy release rate to evaluate the coal seam bump proneness, gives full consideration to the time effect of the residual energy and destruction process during coal-rock failure, overcomes the one-sidedness existing in simple use of energy index and failure time index, and solves the problem of erroneous judgment and misjudgment to bump proneness from the source.

Description

technical field [0001] The invention relates to a method for testing and evaluating the impact tendency of deep hard roof coal seams. Background technique [0002] Rock burst is a phenomenon in which high-strength coal-rock deformation energy induced by mining is released instantaneously, causing strong vibration and extrusion of surrounding rock in the corresponding mining space. The mining depth of my country's coal mines is increasing at a rate of about 10 meters per year, and the frequency and intensity of rock bursts are gradually increasing, which has become one of the main disasters that restrict the safety of mine production in my country. [0003] Practice has shown that rock burst does not occur in all mines, and its occurrence often requires that coal rocks meet certain physical conditions, that is, they have a tendency to burst. The greater the impact tendency of coal rock, the higher the risk of rock burst. In order to measure whether coal rock has impact tend...

AI Technical Summary

Problems solved by technology

Therefore, the interaction between surrounding rock and coal is one of the important factors affecting whether rock burst occurs, especially the deep hard roof conditions. When evaluating the coal seam burst tendency, it is very difficult to ignore the interaction between the hard roof and coal. It may cause an underestimation of the impact tendency of the coal seam, and bury hidden dangers for the safe mining of the mine

Both theoretical research and field practice have shown that for deep coal seams, especially when there is a hard roof above the coal seam, when the impact risk of the coal seam is evaluated simply by the impact tendency index of the coal seam, the phenomenon of "underestimation" often occurs, and it is difficult to evaluate the impact risk of the coal seam. Provide an accurate basis for the prediction and prevention of downburst

[0005] Existing evaluation methods for impact tendency mostly start with single indicators such as energy, failure time, and strength, which cannot fully reflect this essence, are quite one-sided, and are likely to cause misjudgment and misjudgment

For example, for coal bodies with the same dynamic failure time, when the remaining energy is different, the dynamic effect of failure is different, and the impact tendency is also different. It is difficult to give an accurate judgment on this situation only by using the dynamic failure time index

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