Method for evaluating coal mining water inrush dangerousness under water-bearing stratum close to unconsolidated formation

Abstract

The invention discloses a coal mining water inrush risk evaluation method under a near-unconsolidated formation aquifer, which comprises the following steps: S1, determining coal mining water inrush influence factors under the near-unconsolidated formation aquifer according to coal mining water inrush conditions under the near-unconsolidated formation aquifer; s2, performing ground drilling to determine original data of each influence factor; s3, constructing a coal mining water inrush risk evaluation hierarchical structure model under the water-bearing stratum close to the unconsolidated formation; s4, performing normalization processing on the coal mining water inrush influence factors under the close-to-unconsolidated formation confined water layer; s5, establishing a coal mining water inrush risk index method evaluation model under the near-unconsolidated formation aquifer; and S6, coal mining water inrush risk zoning under the water-containing layer near the unconsolidated formation: carrying out coal mining water inrush risk zoning under the water-containing layer near the unconsolidated formation, accurately identifying and grading the coal mining water inrush hidden danger under the water-containing layer near the unconsolidated formation in a mining area, providing a scientific basis for making a coal mining water inrush prevention and control scheme under the water-containing layer near the unconsolidated formation, and ensuring safe mining of a coal mine.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining detection, and in particular to a method for evaluating the danger of water inrush during coal mining under a loose layer aquifer. Background Art

[0002] Energy is the primary bottleneck problem that needs to be solved for my country's sustainable development. The hydrogeological conditions of most coalfields in my country are relatively complex. During the mining process of their coal seams, they will be threatened by a variety of water bodies. The problem of mine water prevention and control is a technical problem in coal mine safety production and scientific research. With the development of coal mining in my country, the problem of coal pressure under "three below" (under buildings, under roads, and under water bodies) has become increasingly prominent, among which coal pressure under water bodies accounts for about 25% of the total amount of coal pressure under "three below". According to preliminary statistics, the mines threatened by water hazards account for 48% of the key coal mines in the country, and the recoverable reserves threatened by water hazards are as high as 25 billion tons. Judging from the production and mining situation in recent years, the annual output of coal threatened by water hazards accounts for 10% of the total reserves. In order to prevent water hazards in the aquifer above the coal seam, a large number of water-retaining coal pillars need to be left in traditional coal mining to protect the aquiclude from being destroyed, thereby ensuring the safe production of the working face.

[0003] Accurately determining the hazard level of water inrush during coal mining near loose strata aquifers and accurately predicting the location of water inrush during coal mining in loose strata aquifers are the prerequisites for evaluating and preventing the hazard level of water inrush during coal mining in loose strata aquifers. At present, most of the methods for determining the hazard level of water inrush during coal mining in loose strata aquifers have single calculation parameters and limited accuracy, and lack a method for zoning the hazard level of water inrush during coal mining in loose strata aquifers based on in-situ test results.

[0004] Therefore, how to solve the problem of quantitative evaluation of water inrush hazard in coal mining near loose aquifers has important guiding significance and practical value for improving coal resource recovery rate and alleviating energy tension. Summary of the invention

[0005] In order to solve the technical problems existing in the background technology, the present invention proposes a method for evaluating the hazard of water inrush in coal mining under a loose layer aquifer.

[0006] The present invention proposes a method for evaluating the risk of water inrush during coal mining in a near-loose layer aquifer, which is characterized by comprising the following steps:

[0007] 1) According to the conditions of water inrush caused by coal mining under the aquifer near the loose layer, the influencing factors of water inrush caused by coal mining under the aquifer near the loose layer are determined, mainly including: the thickness of the overburden above the mined coal seam, the thickness of the aquifer at the bottom of the loose layer, the water richness of the aquifer at the bottom of the loose layer, the thickness of the impermeable layer, and the height of the overburden damage caused by mining.

[0008] 2) Drill holes on the ground to determine the original data of each influencing factor;

[0009] 3) Construct a hierarchical model for evaluating the risk of water inrush during coal mining near loose layer aquifers, and determine the influence weight wi of each influencing factor through the hierarchical model;

[0010] 4) Normalization of the influencing factors of water inrush caused by coal mining near the loose layer aquifer. The following formula is used to normalize the influencing factors of water inrush caused by coal mining near the loose layer aquifer:

[0011]

[0012] Where: Ai is the normalized result; a and b are the lower and upper limits of the normalized range, which can be 0 and 1 respectively; xi is the original data; min(xi) and max(xi) are the minimum and maximum values ​​of the quantized values ​​of each main control factor.

[0013] 5) Establish an evaluation model for the water inrush hazard index method for coal mining near loose layer aquifers, and establish the expression of the water inrush hazard index V for coal mining near loose layer aquifers according to the following formula:

[0014]

[0015] In the formula, k is the number of influencing factors of water inrush caused by coal mining near the loose layer aquifer, which is 5 here; wi is the impact weight; Ai(x,y) is the normalized result of the ith influencing factor; x,y are the coordinates.

[0016] 6) Zoning of water inrush hazard during coal mining near loose strata aquifers. The water inrush hazard index during coal mining near loose strata aquifers is processed by natural classification method to obtain five zones: safe zone, relatively safe zone, transition zone, relatively dangerous zone, and dangerous zone.

[0017] In the present invention, a method for evaluating the hazard of water inrush during coal mining in a near loose stratum aquifer is proposed. Through the method for evaluating the hazard of water inrush during coal mining in a near loose stratum aquifer of the present invention, according to the conditions of water inrush during coal mining in a near loose stratum aquifer, the influencing factors of water inrush during coal mining in a near loose stratum aquifer are determined; the original data of each influencing factor is determined by ground drilling, and normalized; a hierarchical model for evaluating the hazard of water inrush during coal mining in a near loose stratum aquifer is constructed, and the influence weight wi of each influencing factor is determined through the hierarchical model; finally, a hazard index of water inrush during coal mining in a near loose stratum aquifer is established, and zoning of hazard of water inrush during coal mining in a near loose stratum aquifer is carried out, which can accurately identify and classify the hidden dangers of water inrush during coal mining in a near loose stratum aquifer in the mining area, provide a scientific basis for the formulation of a plan for preventing and controlling water inrush during coal mining in a near loose stratum aquifer, and ensure the safe mining of coal mines.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flow chart of a method for evaluating the risk of water inrush in coal mining near loose layer aquifers; DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar symbols throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0021] like Figure 1 A method for evaluating the hazard of water inrush during coal mining near a loose layer aquifer is shown.

[0022] The present invention proposes a method for evaluating the risk of water inrush during coal mining in a near-loose layer aquifer, which is characterized by comprising the following steps:

[0023] 1) According to the conditions of water inrush caused by coal mining under the aquifer near the loose layer, the influencing factors of water inrush caused by coal mining under the aquifer near the loose layer are determined, mainly including: the thickness of the overburden above the mined coal seam, the thickness of the aquifer at the bottom of the loose layer, the water richness of the aquifer at the bottom of the loose layer, the thickness of the impermeable layer, and the height of the overburden damage caused by mining.

[0024] 2) Drill holes on the ground to determine the original data of each influencing factor;

[0025] 3) Construct a hierarchical model for evaluating the risk of water inrush during coal mining near loose layer aquifers, and determine the influence weight wi of each influencing factor through the hierarchical model;

[0026] 4) Normalization of the influencing factors of water inrush caused by coal mining near the loose layer aquifer. The following formula is used to normalize the influencing factors of water inrush caused by coal mining near the loose layer aquifer:

[0027]

[0028] Where: Ai is the normalized result; a and b are the lower and upper limits of the normalized range, which can be 0 and 1 respectively; xi is the original data; min(xi) and max(xi) are the minimum and maximum values ​​of the quantized values ​​of each main control factor.

[0029] 5) Establish an evaluation model for the water inrush hazard index method for coal mining near loose layer aquifers, and establish the expression of the water inrush hazard index V for coal mining near loose layer aquifers according to the following formula:

[0030]

[0031] In the formula, k is the number of influencing factors of water inrush caused by coal mining near the loose layer aquifer, which is 5 here; wi is the impact weight; Ai(x,y) is the normalized result of the ith influencing factor; x,y are the coordinates.

[0032] 6) Zoning of water inrush hazard during coal mining near loose strata aquifers. The water inrush hazard index during coal mining near loose strata aquifers is processed by natural classification method to obtain five zones: safe zone, relatively safe zone, transition zone, relatively dangerous zone, and dangerous zone.

[0033] The present invention evaluates and zones the hazard of water inrush during coal mining in a near-loose layer aquifer through in-situ detection of ground drilling, exploration and calculation of the height of water-conducting fractures, identification of factors affecting water inrush during coal mining in a near-loose layer aquifer, and establishment of an evaluation model for the hazard index method of water inrush during coal mining in a near-loose layer aquifer. This fills in the gap and realizes the grading of the scale and hazard of water inrush during coal mining in a near-loose layer aquifer, providing a scientific basis for the formulation of subsequent water inrush prevention and control plans for coal mining in a near-loose layer aquifer, and ensuring safe mining of coal mines.

[0034] Through the method for evaluating the hazard of water inrush during coal mining under a loose stratum aquifer of the present invention, according to the conditions of water inrush during coal mining under a loose stratum aquifer, the influencing factors of water inrush during coal mining under a loose stratum aquifer are determined; the original data of each influencing factor is determined by ground drilling, and normalized; a hierarchical model for evaluating the hazard of water inrush during coal mining under a loose stratum aquifer is constructed, and the influence weight wi of each influencing factor is determined by the hierarchical model; finally, a hazard index of water inrush during coal mining under a loose stratum aquifer is established, and the hazard zoning of water inrush during coal mining under a loose stratum aquifer is carried out, so that the hidden dangers of water inrush during coal mining under a loose stratum aquifer in the mining area can be accurately identified and classified, so as to provide a scientific basis for the formulation of a prevention and control plan for water inrush during coal mining under a loose stratum aquifer, and ensure the safe mining of coal mines.

[0035] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for evaluating the risk of water inrush during coal mining near a loose layer aquifer, characterized by: The steps include: 1) According to the conditions of water inrush caused by coal mining under the aquifer near the loose layer, the influencing factors of water inrush caused by coal mining under the aquifer near the loose layer are determined, mainly including: the thickness of the overburden above the mined coal seam, the thickness of the aquifer at the bottom of the loose layer, the water richness of the aquifer at the bottom of the loose layer, the thickness of the impermeable layer, and the height of the overburden damage caused by mining. 2) Drill holes on the ground to determine the original data of each influencing factor; 3) Construct a hierarchical model for evaluating the risk of water inrush during coal mining near loose layer aquifers, and determine the influence weight wi of each influencing factor through the hierarchical model; 4) Normalization of the influencing factors of water inrush caused by coal mining near the loose layer aquifer. The following formula is used to normalize the influencing factors of water inrush caused by coal mining near the loose layer aquifer: Where: Ai is the normalized result; a and b are the lower and upper limits of the normalized range, which can be 0 and 1 respectively; xi is the original data; min(xi) and max(xi) are the minimum and maximum values ​​of the quantized values ​​of each main control factor. 5) Establish an evaluation model for the water inrush hazard index method for coal mining near loose layer aquifers, and establish the expression of the water inrush hazard index V for coal mining near loose layer aquifers according to the following formula: In the formula, k is the number of influencing factors of water inrush caused by coal mining near the loose layer aquifer, which is 5 here; wi is the impact weight; Ai(x,y) is the normalized result of the ith influencing factor; x,y are the coordinates. 6) Zoning of water inrush hazard during coal mining near loose strata aquifers. The water inrush hazard index during coal mining near loose strata aquifers is processed by natural classification method to obtain five zones: safe zone, relatively safe zone, transition zone, relatively dangerous zone, and dangerous zone.

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