Method of analyzing influencing factors of contribution rate of elastic energy of top plate during catastrophe of coal body

Abstract

A method of analyzing influencing factors of a contribution rate of elastic energy of a top plate during catastrophe of a coal body; the specific steps are: obtaining coal seam gas pressure; according to a drilling histogram, obtaining coal seam thickness and top plate thickness; taking a core on site and processing the core into a standard test piece; obtaining, by means of an indoor mechanical test, elastic moduli of the top plate and of gas-containing coal, respectively; substituting the obtained elastic moduli and thicknesses of the top plate and of the gas-containing coal into a calculation formula so as to obtain the contribution rate of the elastic energy of the top plate; and analyzing the influence of the contribution rate of the elastic energy of the top plate in the two situations of configuring the same thickness ratio and a different elastic modulus ratio and the same elastic modulus ratio and a different thickness ratio. In the described method, the role of the elastic energy of the top plate in a coal-gas dynamic disaster is fully considered while the influencing factors of the contribution rate of the elastic energy are analyzed. The method has important theoretical significance and practical engineering value. Moreover, the method has positive significance for the prediction and prevention of mining-induced rock burst-coal and gas outburst and other complex dynamic mining disasters.

Claims

1. A method of analyzing influencing factors of a contribution rate of elastic energy of a top plate during catastrophe of a coal body, comprising the following steps: Step 1, calculating the contribution rate of the elastic energy of the top plate: (S.sub.1) obtaining gas-containing coal seam gas pressure p; (S.sub.2) according to a drilling histogram, obtaining gas-containing coal seam thickness h.sub.c and top plate thickness h.sub.r; (S.sub.3) coring the gas-containing coal seam and the top plate, processing the core into a standard test piece, and obtaining, by means of a mechanical test, elastic moduli E.sub.r of the top plate and elastic moduli E.sub.c of the coal seam under the influence of the gas pressure p, respectively; (S.sub.4) calculating the contribution rate of the elastic energy of the top plate according to the data obtained in step (S.sub.1) to step (S.sub.3), $\begin{array}{cc}=.Math.E_c{h}_r/\left(E_c{h}_r+E_r{h}_c\right)100\%& \left(1\right)\end{array}$ in formula (1), is a correction factor, and 0<1; h, and h.sub.c, E.sub.r and E.sub.c satisfy formula (2): $\begin{array}{cc}\{\begin{array}{c}{h}_r={\mathrm{mh}}_c\\ E_r={\mathrm{nE}}_c\end{array}& \left(2\right)\end{array}$ in formula (2), m>0 and n>0; substituting formula (2) into formula (1) to obtain: $\begin{array}{cc}=.Math.n/\left(m+n\right)100\%& \left(3\right)\end{array}$ Step 2, analyzing the influence factor of the contribution rate of the elastic energy of the top plate: according to formula (3), analyzing the influence of m and n on the contribution rate of the elastic energy of the top plate, wherein the following two situations are configured: situation 1: the influence of the same m but different n on ; situation 2: the influence of the same n but different m on ; obtaining the comprehensive influence of m and n on the contribution rate of the elastic energy of the top plate according to situation 1 and situation 2 respectively.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is a flow chart of a method of analyzing influencing factors of a contribution rate of elastic energy of a top plate during catastrophe of a coal body.

[0025] FIG. 2 is an influence distribution diagram of parameter m on according to an embodiment of the present disclosure.

[0026] FIG. 3 is an influence distribution diagram of parameter n on according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to fully embody the features and advantages of the present disclosure, the present disclosure will be described in detail with reference to the attached drawings and specific embodiments.

[0028] As shown in FIG. 1 to FIG. 3, a method of analyzing influencing factors of a contribution rate of elastic energy of a top plate during catastrophe of a coal body is provided, including the following steps: [0029] Step 1, calculating the contribution rate of the elastic energy of the top plate: [0030] (S.sub.1) obtaining gas-containing coal seam gas pressure p; [0031] (S.sub.2) according to a drilling histogram, obtaining gas-containing coal seam thickness h.sub.c and top plate thickness h.sub.r; [0032] (S.sub.3) coring the gas-containing coal seam and the top plate, processing the core into a standard test piece, and obtaining, by means of a mechanical test, elastic moduli E.sub.r of the top plate and elastic moduli E.sub.c of the coal seam under the influence of the gas pressure p, respectively; [0033] (S.sub.4) calculating the contribution rate of the elastic energy of the top plate according to the data obtained in step (S.sub.1) to step (S.sub.3)

[00004]$\begin{array}{cc}=.Math.E_c{h}_r/\left(E_c{h}_r+E_r{h}_c\right)100\%& \left(1\right)\end{array}$ [0034] in formula (1), is a correction factor, and 0<1 h.sub.r and h.sub.c, E.sub.r and E.sub.c satisfy formula (2):

[00005]$\begin{array}{cc}\{\begin{array}{c}{h}_r={\mathrm{mh}}_c\\ E_r={\mathrm{nE}}_c\end{array}& \left(2\right)\end{array}$ [0035] in formula (2), m>0 and n>0; substituting formula (2) into formula (1) to obtain:

[00006]$\begin{array}{cc}=.Math.n/\left(m+n\right)100\%& \left(3\right)\end{array}$ [0036] Step 2, analyzing the influence factor of the contribution rate of the elastic energy of the top plate: [0037] according to formula (3), analyzing the influence of m and n on the contribution rate q of the elastic energy of the top plate, wherein the following two situations are configured: [0038] situation 1: the influence of the same m but different n on ; [0039] situation 2: the influence of the same n but different m on ; [0040] obtaining the comprehensive influence of m and n on the contribution rate of the elastic energy of the top plate according to situation 1 and situation 2 respectively.

EMBODIMENT

[0041] In order to further analyze the specific influence of m and n on , the analysis is carried out within the m range of [0.1,10] and the n range of [0.1,12], and the value of is 1, which is divided into the following two situations.

[0042] Situation 1: the influence of the same layer thickness m but different elastic modulus n on .

[0043] It can be seen from FIG. 2 that when the ratio of thickness of the rock to the coal is the same (equal to m) in a two-body combined structure, the greater the ratio n of the elastic modulus of the rock to the coal, the smaller the contribution rate of the elastic energy of the top plate. However, the overall contribution rate of the elastic energy of the top plate increases with the increase of the ratio m of the thickness of the rock to the coal.

[0044] Situation 2: the influence of the same n but different m on the contribution rate of the elastic energy of the top plate.

[0045] It can be seen from FIG. 3 that when the ratio of the elastic modulus of the rock to the coal is the same (equal to n) in a two-body combined structure, the greater the ratio m of the thickness of the rock to the coal, the greater the contribution rate of the elastic energy of the top plate. However, the overall contribution rate of the elastic energy of the top plate decreases with the increase of the ratio n of the elastic modulus of the rock to the coal, but the decreasing trend gradually slows down.

[0046] Although the specific embodiment of the present disclosure has been described with the attached drawings, it is not a limitation on the scope of protection of the present disclosure. Those skilled in the art should understand that on the basis of the technical scheme of the present disclosure, various modifications or transformations that can be made by those skilled in the art without creative labor are still within the scope of protection of the present disclosure.