Method and device for determining development status of separation layer of coal mine

Patent metadata

Field	Value
Publication number	US-12091972-B1
Application number	US-202418596373-A
Country	US
Kind code	B1
Filing date	Mar 5, 2024
Priority date	May 11, 2023
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

Disclosed are a method and a related device for determining a development status of a separation layer in a coal mine. The method includes: obtaining surface subsidence variation data of the coal mine within a preset time interval, rock stress variation data of a caving zone of the coal mine and water pressure variation data; determining a height decrease of the caving zone based on the rock stress variation data and the water pressure variation data; and determining the development status of the separation layer of the coal mine based on the height decrease and the surface subsidence variation data.

First claim

What is claimed is:

1. A method for determining a development status of a separation layer in a coal mine, comprising:
obtaining surface subsidence variation data of the coal mine within a preset time interval by a rock movement monitoring station set on a ground surface of the coal mine or by at least one Unmanned Aerial Vehicle;
obtaining rock stress variation data of a caving zone corresponding to the ground surface of the coal mine by a stress measurement device buried in the caving zone;
obtaining water pressure variation data of the caving zone corresponding to the ground surface of the coal mine by a water pressure measurement device buried in the caving zone;
determining a height decrease of the caving zone based on the rock stress variation data and the water pressure variation data, comprising:
calculating a maximum development height of the caving zone:

P
=

∑

i
=
1

n

γ
i

⁢

s
i

H
=

∑

i
=
1

n
-
1

s
i

+

P
0

-
P

γ
n

wherein, P refers to an intensity of pressure of the caving zone, in Pa; γ i refers to a unit weight of a i th layer of the caving zone, in N/m3; s i refers to a thickness of the i th layer of the caving zone, in m; n refers to a total number of layers of the caving zone; P 0 refers to a stable intensity of pressure that a bottom plate of the caving zone experiences within the preset time interval; γ n refers to a unit weight of a n th layer of the collapsed rock mass; and H refers to the maximum development height of the caving zone;
calculating a total stress of the caving zone based on the maximum development height:

r
0

=

M

H
+
M

×
100
⁢
%

σ

i
⁢
j

=

(

1
-

r
0

)

⁢

P
0

+

r
0

⁢

p
0

wherein, M refers to a mining height from the ground surface to a position of the stress measurement device or the water pressure measurement device; H refers to the maximum development height of the caving zone; r 0 refers to an initial porosity of blocks within a cubic a range of a cube occupied by a goaf of the coal mine; P 0 refers to the stable intensity of pressure that a bottom plate of the caving zone experiences within the preset time interval; p 0 refers to a pore water pressure in the goaf when the maximum development height of the caving zone is reached; σ ij refers to the total stress of the caving zone;
calculating the height decrease of the caving zone based on the total stress:

Δ
⁢
h

=

M
-

P
i

-

σ

i
⁢
j

σ

i
⁢
j

-

p
i

⁢
H

wherein, P i refers to the rock stress variation data; p i refers to the water pressure variation data; σ ij refers to the total stress of the caving zone; H refers to the maximum development height of the caving zone; M refers to a mining height where a stress measurement device or a water pressure measurement device locates; Δh refers to the height decrease of the caving zone;

in response to determining a difference between the height decrease and the surface subsidence variation data is less than a preset threshold, determining the development status of the separation layer is an undeveloped status; and
in response to determining the difference between the height decrease and the surface subsidence variation data is larger than the preset threshold, determining the development status of the separation layer is a developed status; determining a development degree of the separation layer according to the difference between the height decrease and the surface subsidence variation data; and in response to determining the development degree reaches a preset early warning threshold, taking control measures for the caving zone to avoid occurrences of water damages.

2. The method according to claim 1 , wherein, obtaining surface subsidence variation data of the coal mine within a preset time interval comprises:
determining a first coordinate of the ground surface of the coal mine at a starting time of the preset time interval;
determining a second coordinate of the ground surface of the

Assignees

• Univ China Mining

Inventors

• Zeng Yifan
• Mei Aoshuang
• Wu Qiang
• Wei Huaming
• Cui Yashuai
• Meng Shihao
• Yang Weihong
• Pang Kai
• Yang Liang
• Xing Yidi

Classifications

• E21C41/18 Primary

  for brown or hard coal · CPC title

• E21F17/18

  Special adaptations of signalling or alarm devices (for mine lifts B66B; gas-sensitive devices per se G01N) · CPC title

• E21C39/00 Primary

  Devices for testing in situ the hardness or other properties of minerals, e.g. for giving information as to the selection of suitable mining tools · CPC title

• E21C2100/00

  Modeling, simulating or designing mining operations · CPC title

• G01D21/02

  Measuring two or more variables by means not covered by a single other subclass · CPC title