A method and system for judging the danger of water inrush from the bottom plate of deep well mining

Abstract

The invention belongs to the technical field of coal mine water hazard prevention and control, and provides a method and system for judging the danger of water inrush from a deep well mining floor. Firstly, the destruction depth of the mining floor is obtained based on the theory of semi-infinite elastic body mechanics and the Mohr-Coulomb yield criterion, the height of the pressurized water rise is obtained based on the principle of fracture mechanics and the Mises yield criterion, and the thickness of the bottom plate water-proof key zone is obtained by subtracting the destruction depth of the mining floor and the height of the pressurized water rise from the distance between the coal seam and the pressurized water; then, according to the destruction depth of the mining floor, the height of the pressurized water rise and the thickness of the bottom plate water-proof key zone, and the limit equilibrium theory, the limit water pressure of the bottom plate water inrush and the water inrush coefficient are obtained; finally, the danger of water inrush from the mining floor is judged by comparing the water inrush coefficient with a preset value, and comparing the limit water pressure of the bottom plate water inrush with a preset value. The whole process avoids the influence of human subjective factors and ensures the accuracy of the evaluation result.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine water hazard prevention and control, and in particular relates to a method and system for judging the danger of water inrush from a bottom plate during deep well mining. Background Art

[0002] Floor water inrush seriously threatens the safe production of coal mines, not only causing casualties and economic losses, but also causing huge pollution and damage to the water resources and environment in the mining area. With the increasing mining depth and mining intensity, the hydrogeological conditions of coal fields are becoming more and more complex, and the threat of floor pressurized water to mine safety is becoming increasingly serious. Therefore, accurately evaluating and predicting the danger of floor water inrush is crucial for mine safety production and groundwater resource protection.

[0003] The inventors found that, currently, the hazard evaluation of floor water inrush in deep well mining is mostly carried out using methods such as mathematical statistics, fuzzy mathematics, grey theory and neural network to evaluate the degree of hazard of floor water inrush; however, often in the process of evaluation, human subjective factors are introduced, resulting in a large difference between the evaluation results and the actual results. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a method and system for judging the danger of water inrush from the bottom plate of deep well mining. Based on the lower three-zone theory and mechanics theory, the present invention solves the subjectivity of the prediction results of mathematical methods, the qualitative-semi-quantitative results, and the difficulty in obtaining analytical solutions to the danger of water inrush from the bottom plate of mining.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] In a first aspect, the present invention provides a method for determining the danger of water inrush from a deep well mining floor, comprising:

[0007] Obtain relevant index data of mining floor rock mass and relevant index data of confined water;

[0008] According to the relevant index data of the mining floor rock mass, the semi-infinite elastic body mechanics theory and the Mohr-Coulomb yield criterion, the failure depth of the mining floor is obtained;

[0009] According to the relevant index data of confined water, the principle of fracture mechanics and Mises yield criterion, the height of confined water rise is obtained;

[0010] The thickness of the critical water-blocking zone of the floor is obtained by deducting the mining floor damage depth and the water pressure rise height from the distance between the coal seam and the pressurized water;

[0011] According to the mining floor failure depth, the pressure water rise height, the thickness of the floor water-isolating key zone, and the limit equilibrium theory, the floor water inrush limit water pressure is obtained;

[0012] Calculate the ratio of the water pressure of the confined water to the thickness of the bottom plate water-isolating key zone to obtain the water inrush coefficient;

[0013] By comparing the water inrush coefficient with a preset value, and comparing the bottom plate water inrush limit water pressure with a preset value, the danger of bottom plate water inrush caused by mining is judged.

[0014] Furthermore, the index data include the average bulk density of overlying rock strata, burial depth of coal seams, width of mine pressure unloading zone, mine pressure stress concentration coefficient, width from coal wall to stress peak, width from stress peak to original rock stress, top control distance, confined water pressure, distance from coal seam to confined water layer, bulk density of bottom plate aquiclude, cohesion and internal friction angle.

[0015] Furthermore, based on the theory of semi-infinite elastic body mechanics, the stress component at any point in the mining floor rock mass is obtained:

[0016]

[0017] Among them, dε is the length of the micro-unit of the bottom rock mass; x is the horizontal coordinate value of any point of the bottom rock mass; y is the vertical coordinate value of any point of the bottom rock mass; K is the stress concentration coefficient; H is the burial depth; γ is the bulk density of the rock mass; P is the water pressure of the confined water; L is the width of the top control area of ​​the working face; a is the horizontal strike length of the triangular linear load in the stress reduction zone behind the working face; b is the horizontal strike length of the coal wall in front of the working face to the stress peak; c is the horizontal strike length of the trapezoidal linear load in front of the stress peak; h is the distance from the bottom of the coal seam to the confined water.

[0018] Furthermore, the mining floor failure depth is:

[0019]

[0020] Among them, x is the horizontal coordinate value of any point of the bottom rock mass; y is the vertical coordinate value of any point of the bottom rock mass; is the friction angle of the bottom rock mass; τ max is the maximum shear stress of the bottom rock mass.

[0021] Furthermore, the height of the pressurized water rise is:

[0022]

[0023]

[0024]

[0025] in, θ is the crack expansion angle; μ is the Poisson's ratio; σ1 and σ3 are the maximum principal stress and the minimum principal stress respectively; β is the angle between the crack and σ1 direction; σ nis the normal stress on the crack surface; is the internal friction angle; w is the water content; t is the immersion time; c n is the cohesion of the filling material in the crack surface; r is the half crack length; P is the confined water pressure.

[0026] Furthermore, the ultimate water pressure of bottom plate water inrush is:

[0027]

[0028] Where C is the cohesion of the bottom slab water-proof key layer; is the internal friction angle of the key waterproof layer of the bottom plate; K is the stress concentration coefficient; H is the buried depth of the coal seam; h3 is the height of the pressurized water rise; h1 is the bottom plate failure depth; h2 is the thickness of the key waterproof zone of the bottom plate; γ is the bulk density of the bottom plate rock mass; a is the horizontal strike length of the triangular linear load in the stress reduction zone behind the working face.

[0029] Furthermore, the water inrush coefficient is less than the preset value, indicating that there is no danger of water inrush in the coal seam floor; the ultimate water pressure of water inrush in the floor is greater than the actual water pressure that the floor can withstand, indicating that no water inrush has occurred.

[0030] In a second aspect, the present invention also provides a system for determining the danger of water inrush from the bottom plate of a deep well mining operation, comprising:

[0031] The data acquisition module is configured to: obtain relevant index data of the mining floor rock mass and relevant index data of the confined water;

[0032] The mining floor failure depth calculation module is configured to: obtain the mining floor failure depth based on the relevant index data of the mining floor rock mass, the semi-infinite elastic body mechanics theory and the Mohr-Coulomb yield criterion;

[0033] The confined water rise height calculation module is configured to: obtain the confined water rise height according to relevant index data of confined water, fracture mechanics principle and Mises yield criterion;

[0034] The module for calculating the thickness of the bottom plate water-proof key zone is configured to: obtain the thickness of the bottom plate water-proof key zone by subtracting the mining bottom plate damage depth and the water pressure rise height from the distance between the coal seam and the confined water;

[0035] The bottom plate water inrush limit water pressure calculation module is configured to: obtain the bottom plate water inrush limit water pressure according to the mining bottom plate damage depth, the pressure water rise height and the bottom plate water-blocking key zone thickness, and the limit equilibrium theory;

[0036] The water burst coefficient calculation module is configured to: calculate the ratio of the water pressure of the confined water to the thickness of the bottom plate water-isolating key zone to obtain the water burst coefficient;

[0037] The judgment module is configured to judge the danger of water inrush from the bottom plate caused by mining by comparing the water inrush coefficient with a preset value and comparing the bottom plate water inrush limit water pressure with a preset value.

[0038] In a third aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for determining the danger of water inrush from the bottom plate of deep well mining as described in the first aspect.

[0039] In a fourth aspect, the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for determining the danger of water inrush from the bottom plate of deep well mining as described in the first aspect are implemented.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. In the present invention, the failure depth of the mining floor is first obtained based on the theory of semi-infinite elastic body mechanics and the Mohr-Coulomb yield criterion, the height of the pressurized water is obtained based on the principle of fracture mechanics and the Mises yield criterion, and the thickness of the critical zone of the floor water-proofing is obtained by subtracting the failure depth of the mining floor and the height of the pressurized water from the distance between the coal seam and the pressurized water; then, according to the failure depth of the mining floor, the height of the pressurized water, the thickness of the critical zone of the floor water-proofing, and the limit equilibrium theory, the ultimate water pressure of the floor water inrush and the water inrush coefficient are obtained; finally, the comparison between the water inrush coefficient and the preset value, and the comparison between the ultimate water pressure of the floor water inrush and the preset value are used to judge the danger of water inrush of the mining floor; based on the lower three-zone theory and the mechanics theory, the subjectivity of the prediction results of the mathematical method, the qualitative-semi-quantitative results, and the difficulty in obtaining the analytical solution of the danger of water inrush of the mining floor and other related problems are solved, and the whole process avoids the influence of human subjective factors and ensures the accuracy of the evaluation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0043] Figure 1 is a flowchart of the steps of Embodiment 1 of the present invention;

[0044] Figure 2 This is a schematic diagram of the spatial distribution of three zones under the bottom plate of Example 1 of the present invention;

[0045] Figure 3 This is a depth analysis diagram of the mining-induced floor damage in Example 1 of the present invention. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0047] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0048] Embodiment 1:

[0049] This embodiment provides a method for determining the danger of water inrush from the bottom plate of a deep well mining operation, comprising:

[0050] Obtain relevant index data of mining floor rock mass and relevant index data of confined water;

[0051] According to the relevant index data of the mining floor rock mass, the semi-infinite elastic body mechanics theory and the Mohr-Coulomb yield criterion, the failure depth of the mining floor is obtained;

[0052] According to the relevant index data of confined water, the principle of fracture mechanics and Mises yield criterion, the height of confined water rise is obtained;

[0053] The thickness of the critical water-blocking zone of the floor is obtained by deducting the mining floor damage depth and the water pressure rise height from the distance between the coal seam and the pressurized water;

[0054] According to the mining floor failure depth, the pressure water rise height, the thickness of the floor water-isolating key zone, and the limit equilibrium theory, the floor water inrush limit water pressure is obtained;

[0055] Calculate the ratio of the water pressure of the confined water to the thickness of the bottom plate water-isolating key zone to obtain the water inrush coefficient;

[0056] By comparing the water inrush coefficient with a preset value, and comparing the bottom plate water inrush limit water pressure with a preset value, the danger of bottom plate water inrush caused by mining is judged.

[0057] In this embodiment, firstly, the exploration data of the mining floor rock mass and pressurized water, the physical and mechanical parameters of the floor rock mass, the mining parameters of the working face and other related index data required for the following theoretical analysis are obtained; then, for the mining floor failure zone, the stress component at any point in the mining floor rock mass is obtained based on the semi-infinite elastic body mechanics theory, and the depth of the mining floor failure of the working face is determined in combination with the Mohr-Coulomb criterion; for the pressurized water lifting zone, considering the actual influence of the mine pressure and the pressurized water pressure on the stress field at the crack tip, the single crack tip plastic zone range of the floor rock mass in the pressurized water lifting zone is analyzed based on fracture mechanics, thereby obtaining the pressurized water lifting height; for the floor water-blocking key zone, the thickness of the floor water-blocking key zone is determined in combination with the exploration data, and then based on the limit equilibrium theory and the water inrush coefficient, the criterion for the water inrush hazard of the mining floor is obtained, and the water inrush hazard of the mining floor is judged.

[0058] By collecting exploration data on mining floor rock and confined water, physical and mechanical index test data, and working face mining parameters and other index data, a data basis is provided for the following theoretical analysis. Specifically, the index data include the average bulk density of overlying rock strata, coal seam burial depth, mine pressure unloading zone width, mine pressure stress concentration coefficient, coal wall to stress peak width, stress peak to original rock stress width, top control distance, confined water pressure, distance from coal seam to confined water layer, bulk density of floor aquiclude, cohesion and internal friction angle, etc.

[0059] For the mining floor damage zone, the stress components at any point in the mining floor rock mass are obtained based on the semi-infinite elastic body mechanics theory, mainly including: based on the mine pressure theory and elastic mechanics theory, a working face strike mechanics model is established to solve the vertical, horizontal and shear stress distribution evolution laws at any point in the floor rock mass under the action of mine pressure and confined water:

[0060]

[0061] Among them, dε is the length of the micro-unit of the bottom rock mass; x is the horizontal coordinate value of any point of the bottom rock mass; y is the vertical coordinate value of any point of the bottom rock mass; K is the stress concentration factor; H is the burial depth, m; γ is the specific gravity of the rock mass, kN / m 3 ; P—water pressure of confined water, MPa; L—width of top control area of ​​working face, m; a—horizontal strike length of triangular linear load in stress reduction zone behind working face, m; b—horizontal strike length from coal wall in front of working face to stress peak, m; c—horizontal strike length of trapezoidal linear load in front of stress peak, m; h—distance from coal seam bottom to confined water, m.

[0062] Get the bottom rock mass failure criterion f(z,y), if f(z,y)>0:

[0063]

[0064] in, is the friction angle of the bottom rock mass; τ max is the maximum shear stress of the bottom rock mass.

[0065] The main methods to obtain the height of the pressurized water lifting are as follows: using the principle of fracture mechanics, taking into account the actual influence of the mine pressure and the pressurized water pressure on the stress field at the crack tip, and combining the Mises strength criterion, the plastic zone range of the single crack tip of the bottom rock mass in the pressurized water lifting zone is analyzed, thereby obtaining the height of the pressurized water lifting:

[0066]

[0067]

[0068]

[0069] Where θ is the crack expansion angle; μ is the Poisson's ratio; p is the confined water pressure; f n is the friction coefficient of the crack surface, is the friction angle, c n is the cohesion of the filling material in the crack surface; τ n The effective shear stress that causes relative sliding of the crack surface is: n =τ n '-σ n f n -c n , τ n 'Shear stress on the crack surface; w is the water content; t is the immersion time, and the stress intensity factor K of the crack tip type I and II Ⅰ , K Ⅱ ; r is the half crack length; σ1 and σ3 are the maximum principal stress and the minimum principal stress respectively; the angle between the crack and σ1 is β; σ n and τ n are the normal stress and shear stress on the crack surface, respectively.

[0070] The criteria for judging the danger of water inrush from the mining floor mainly include: the distance between the coal seam and the pressurized water minus the floor damage depth minus the height of the pressurized water rise, which is the thickness of the key water-isolating zone of the floor.

[0071] Based on the limit equilibrium theory, the critical water pressure of the bottom slab water-proof key layer damage is obtained, also known as the bottom slab water inrush limit water pressure P2:

[0072]

[0073] Where C is the cohesion of the bottom plate water-proof key layer, MPa; is the internal friction angle of the key waterproof layer of the bottom plate, °; H is the buried depth of the coal seam, h3 is the height of the pressurized water rise; h1 is the bottom plate failure depth; h2 is the thickness of the key waterproof zone of the bottom plate; the bulk density of the bottom plate rock mass is γ; a is the horizontal strike length of the triangular linear load in the stress reduction zone behind the working face, m.

[0074] The water inrush coefficient is equal to the ratio of the water pressure of the confined water to the thickness of the key water-proof zone of the bottom plate, and then the water inrush hazard of the bottom plate is obtained. The limit equilibrium theory and the water inrush coefficient method are combined to determine the water inrush hazard of the bottom plate caused by mining.

[0075] This embodiment overcomes the related difficulties in the prior art such as the interference of human subjective factors in the prediction results of water inrush from mining floor, the uncertainty of qualitative and semi-quantitative results, and the difficulty in obtaining analytical solutions to the hazard of water inrush from mining floor. It is based on the theory of the "lower three zones" of the floor, analyzes the damage zone of the mining floor based on elastic mechanics, analyzes the height of the pressurized water based on fracture mechanics, and then analyzes the stability of the key water-isolating zone of the floor based on the limit equilibrium theory and the water inrush coefficient method, thereby assessing the hazard of water inrush from mining floor.

[0076] Example 2

[0077] This embodiment provides a theoretical method for determining the danger of water inrush from the floor of a deep well mining operation. The method for determining the danger of water inrush from the floor of a deep well mining operation in Embodiment 1 is described with reference to the data of a certain coal mine. Specifically,

[0078] S1. Collect exploration data of mining floor rock mass, confined water, physical and mechanical index test data, and relevant index data such as working face mining parameters; wherein the relevant index data include average bulk density of overlying rock strata, coal seam burial depth, width of mine pressure unloading zone, mine pressure stress concentration coefficient, width from coal wall to stress peak, width from stress peak to original rock stress, top control distance, confined water pressure, distance from coal seam to confined water layer, bulk density of floor aquiclude, cohesion and internal friction angle, etc., specifically:

[0079] Taking the geological and mining conditions of a coal mine working face as the background, the width of the unloading area in the goaf is a = 55m, the top control distance L = 5m, the width from the coal wall in front of the working face to the stress peak b = 10m, the width from the stress peak in front of the working face to the original rock stress c = 25m, and the average bulk density of the overlying rock γ = 25KN / m 3 , coal seam burial depth H = 800m, distance from coal seam to confined water h = 40m, confined water pressure P = 2MPa, stress concentration factor K = 3.5. Average uniaxial compressive strength of bottom plate aquiclude Rc = 40MPa, internal friction angle Cohesion C = 5.2MPa, bulk density γ = 21KN / m3, Poisson's ratio μ = 0.25.

[0080] S2, such as Figure 2As shown in the figure, based on the "lower three zones" theory of the floor, the stress components at any point in the mining floor rock mass are obtained based on the semi-infinite elastic body mechanics theory for the mining floor failure zone. Combined with the Mohr-Coulomb criterion, it is analytically determined that the failure shape of the mining floor of the working face is roughly "spoon" shaped, with a maximum depth of 14m, as shown in the figure. Figure 3 shown.

[0081] S3. For the confined water lifting zone, considering the actual influence of mine pressure and confined water pressure on the stress field at the crack tip, the plastic zone range of the single crack tip of the bottom rock mass in the confined water lifting zone is analyzed based on fracture mechanics, and the confined water lifting height is obtained to be 2.3m.

[0082] S4. Obtain the danger of water inrush from the bottom plate, that is: water inrush coefficient = pressure of pressurized water / thickness of effective waterproof layer = 2 / (40-14-2.3) = 0.084MPa / m<0.1MPa / m, there is no danger of water inrush from the bottom plate of the coal seam; among them, 0.1MPa / m can be understood as a preset value set according to actual conditions.

[0083] S5. Based on the limit equilibrium theory of aquiclude, it is calculated that: P2 = 3.9MPa>p' = 2MPa, that is, the limit water pressure that the coal seam floor can withstand is greater than the actual water pressure that the floor can withstand, and no water inrush occurs; wherein, the limit water pressure greater than the actual water pressure that the floor can withstand can be understood as a preset value set according to actual conditions. Combining the limit equilibrium theory and the water inrush coefficient method, it is determined that there is no danger of water inrush in the mining floor, and the prediction and evaluation results are consistent with the actual mining results, verifying the accuracy of the prediction results of the present invention. The prediction analytical solution can provide a certain theoretical basis for pressure mining.

[0084] Embodiment 3:

[0085] This embodiment provides a system for determining the danger of water inrush from the bottom plate of a deep well mining operation, comprising:

[0086] The data acquisition module is configured to: obtain relevant index data of the mining floor rock mass and relevant index data of the confined water;

[0087] The mining floor failure depth calculation module is configured to: obtain the mining floor failure depth based on the relevant index data of the mining floor rock mass, the semi-infinite elastic body mechanics theory and the Mohr-Coulomb yield criterion;

[0088] The confined water rise height calculation module is configured to: obtain the confined water rise height according to relevant index data of confined water, fracture mechanics principle and Mises yield criterion;

[0089] The module for calculating the thickness of the bottom plate water-proof key zone is configured to: obtain the thickness of the bottom plate water-proof key zone by subtracting the mining bottom plate damage depth and the water pressure rise height from the distance between the coal seam and the confined water;

[0090] The bottom plate water inrush limit water pressure calculation module is configured to: obtain the bottom plate water inrush limit water pressure according to the mining bottom plate damage depth, the pressure water rise height and the bottom plate water-blocking key zone thickness, and the limit equilibrium theory;

[0091] The water burst coefficient calculation module is configured to: calculate the ratio of the water pressure of the confined water to the thickness of the bottom plate water-isolating key zone to obtain the water burst coefficient;

[0092] The judgment module is configured to judge the danger of water inrush from the bottom plate caused by mining by comparing the water inrush coefficient with a preset value and comparing the bottom plate water inrush limit water pressure with a preset value.

[0093] The working method of the system is the same as the method for determining the danger of water inrush from the bottom plate of deep well mining in Example 1, and will not be repeated here.

[0094] Embodiment 4:

[0095] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the method for determining the danger of water inrush from the bottom plate of deep well mining described in Example 1 are implemented.

[0096] Embodiment 5:

[0097] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the method for determining the danger of water inrush from the bottom plate of deep well mining described in Example 1 are implemented.

[0098] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A method for judging the danger of water inrush from the bottom plate of deep well mining, characterized in that: include: Obtain relevant index data of mining floor rock mass and relevant index data of confined water; Based on the relevant index data of the mining floor rock mass, as well as the semi-infinite elastic body mechanics theory and Mohr-Coulomb Yield criterion, and obtain the failure depth of mining floor; Based on the relevant index data of pressurized water, as well as the principles of fracture mechanics and Mises Yield criterion, the height of the confined water rise is obtained; The thickness of the critical water-blocking zone of the floor is obtained by deducting the mining floor damage depth and the water pressure rise height from the distance between the coal seam and the pressurized water; According to the mining floor failure depth, the pressure water rise height, the thickness of the floor water-isolating key zone, and the limit equilibrium theory, the floor water inrush limit water pressure is obtained; Calculate the ratio of the water pressure of the confined water to the thickness of the bottom plate water-isolating key zone to obtain the water inrush coefficient; By comparing the water inrush coefficient with a preset value, and comparing the bottom plate water inrush limit water pressure with a preset value, the danger of the bottom plate water inrush caused by mining is judged; The depth of mining floor damage is: ； in, x is the horizontal coordinate value of any point in the bottom rock mass; y is the ordinate value of any point in the bottom rock mass; is the friction angle of the bottom rock mass; is the maximum shear force of the bottom rock mass; and are stress components in different directions; The height of the pressurized water rise is: ； ； ； in, is the crack expansion angle; is Poisson's ratio; σ1 and σ3 are the maximum principal stress and the minimum principal stress respectively; is the angle between the crack and the σ1 direction; is the normal stress on the crack surface; is the friction angle; w is the moisture content; t is the immersion time; is the cohesion of the filling material in the crack surface; r is the half crack length; P For pressurized water pressure; The ultimate water pressure of bottom plate water inrush is: ； In the formula, C The cohesion of the key layer for waterproofing the bottom slab; is the internal friction angle of the bottom plate water-proof key layer; K is the stress concentration factor; H is the depth of coal seam; h 3 is the height of pressurized water rise; h 1 is the bottom plate damage depth; h 2 is the thickness of the bottom plate water-proof key zone; γ is the bulk density of the bottom rock mass; a It is the horizontal strike length of the triangular linear load in the stress reduction zone behind the working face.

2. A method for determining the danger of water inrush from the bottom plate of a deep well mining as claimed in claim 1, characterized in that: The index data include the average bulk density of overlying rock strata, burial depth of coal seams, width of mine pressure unloading zone, mine pressure stress concentration coefficient, width from coal wall to stress peak, width from stress peak to original rock stress, top control distance, confined water pressure, distance from coal seam to confined water layer, bulk density of bottom plate aquiclude, cohesion and internal friction angle.

3. A method for determining the danger of water inrush from the bottom of a deep well as claimed in claim 1, characterized in that: Based on the theory of semi-infinite elastic body mechanics, the stress component at any point in the mining floor rock mass is obtained: in, is the length of the micro-unit of the basement rock mass; x is the horizontal coordinate value of any point in the bottom rock mass; y is the ordinate value of any point in the bottom rock mass; K is the stress concentration factor; H For burial depth; γ is the bulk density of the rock mass; P For pressurized water pressure; L Control the width of the top area of ​​the working surface; a is the horizontal strike length of the triangular linear load in the stress reduction zone behind the working face; b It is the horizontal strike length from the coal wall in front of the working face to the stress peak; c is the horizontal length of the trapezoidal linear load in front of the stress peak; h It is the distance from the coal seam floor to the pressurized water.

4. A method for determining the danger of water inrush from the bottom plate of a deep well mining as claimed in claim 1, characterized in that: If the water inrush coefficient is less than the preset value, it means that there is no danger of water inrush from the coal seam floor; if the ultimate water pressure of water inrush from the floor is greater than the actual water pressure that the floor can withstand, it means that no water inrush has occurred.

5. A system for judging the danger of water inrush from the bottom plate of deep well mining, characterized in that: include: The data acquisition module is configured to: obtain relevant index data of the mining floor rock mass and relevant index data of the confined water; The mining floor failure depth calculation module is configured as follows: based on the relevant index data of the mining floor rock mass, the semi-infinite elastic body mechanics theory and Mohr-Coulomb Yield criterion, and obtain the failure depth of mining floor; The module for calculating the height of the pressure water rise is configured as follows: based on the relevant index data of the pressure water, the principles of fracture mechanics and Mises Yield criterion, the height of the confined water rise is obtained; The module for calculating the thickness of the bottom plate water-proof key zone is configured to: obtain the thickness of the bottom plate water-proof key zone by subtracting the mining bottom plate damage depth and the water pressure rise height from the distance between the coal seam and the confined water; The bottom plate water inrush limit water pressure calculation module is configured to: obtain the bottom plate water inrush limit water pressure according to the mining bottom plate damage depth, the pressure water rise height and the bottom plate water-blocking key zone thickness, and the limit equilibrium theory; The water burst coefficient calculation module is configured to: calculate the ratio of the water pressure of the confined water to the thickness of the bottom plate water-isolating key zone to obtain the water burst coefficient; The judgment module is configured to judge the danger of water inrush on the mining floor by comparing the water inrush coefficient with a preset value and comparing the water inrush limit pressure on the floor with a preset value; The depth of mining floor damage is: ； in, x is the horizontal coordinate value of any point in the bottom rock mass; y is the ordinate value of any point in the bottom rock mass; is the friction angle of the bottom rock mass; is the maximum shear force of the bottom rock mass; and are stress components in different directions; The height of the pressurized water rise is: ； ； ； in, is the crack expansion angle; is Poisson's ratio; σ1 and σ3 are the maximum principal stress and the minimum principal stress respectively; is the angle between the crack and the σ1 direction; is the normal stress on the crack surface; is the friction angle; w is the moisture content; t is the immersion time; is the cohesion of the filling material in the crack surface; r is the half crack length; P For pressurized water pressure; The ultimate water pressure of bottom plate water inrush is: ； In the formula, C The cohesion of the key layer for waterproofing the bottom slab; is the internal friction angle of the bottom plate water-proof key layer; K is the stress concentration factor; H is the depth of coal seam; h 3 is the height of pressurized water rise; h 1 is the bottom plate damage depth; h 2 is the thickness of the bottom plate water-proof key zone; γ is the bulk density of the bottom rock mass; a It is the horizontal strike length of the triangular linear load in the stress reduction zone behind the working face.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method for judging the danger of water inrush from the bottom plate of deep well mining as described in any one of claims 1 to 4 are implemented.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method for judging the danger of water inrush from the bottom plate of deep well mining as described in any one of claims 1-4 are implemented.

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