Method, device and computer program product for determining a mining pressure zone

Abstract

The application provides a method, device and computer program product for determining a mine pressure area. The method comprises: obtaining a first stress of a first coal pillar of a first coal seam working face at a first time; obtaining a second stress of a second coal pillar of a second coal seam working face at a second time; determining the mine pressure area according to the size relationship between the first stress and the second stress; and determining the support degree of the coal mine according to the mine pressure area. The scheme solves the problem of poor mining efficiency of the triangular oblique coal pillar working face in the prior art due to the inability to determine the mine pressure of the triangular oblique coal pillar working face.

Description

Technical Field

[0001] This application relates to the field of coal mining technology, and more specifically, to a method, apparatus, computer-readable storage medium, and computer program product for determining a mining pressure zone. Background Technology

[0002] Compared to single-seam mining, close-range coal seam mining is more susceptible to the concentrated stress of coal pillars left over from the overlying coal seam, leading to stronger mine pressure phenomena in the working face and roadways of the lower coal seam, seriously threatening safe mining. In shallow-buried close-range coal seam mining, the overlying coal pillars are mostly wall-type section pillars left over from conventional three-way layouts; for some corner coal or triangular coal pillars, room-pillar or roadway-pillar mining is mostly adopted to recover the triangular coal pillars.

[0003] However, current plans have very little research on the mining pressure of triangular oblique coal pillar working faces, resulting in poor mining efficiency of triangular oblique coal pillar working faces. Summary of the Invention

[0004] The main objective of this application is to provide a method, apparatus, computer-readable storage medium, and computer program product for determining the mining pressure zone, so as to at least solve the problem in the prior art that the mining efficiency of the working face of the triangular oblique coal pillar is poor because the mining pressure of the working face of the triangular oblique coal pillar cannot be determined.

[0005] To achieve the above objectives, according to one aspect of this application, a method for determining a mining pressure zone is provided, comprising: obtaining a first stress of a first coal pillar at a first moment in a first coal seam working face, wherein the first coal pillar is a coal pillar located in the first coal seam working face, the first coal seam working face is a working face with a coal seam in a coal mine, and the first moment is any moment of coal mining; obtaining a second stress of a second coal pillar at a second moment in a second coal seam working face, wherein the first coal seam working face and the second coal seam working face are separated by a predetermined distance, the area between the first coal seam working face and the second coal seam working face is a triangular area, the first moment is earlier than the second moment, the second coal pillar is a coal pillar located in the second coal seam working face, and the first coal pillar and the second coal pillar are obliquely intersecting; determining a mining pressure zone based on the magnitude relationship between the first stress and the second stress, wherein the difference between the first stress and the second stress is directly proportional to the magnitude of the mining pressure; and determining the degree of support for the coal mine based on the mining pressure zone, wherein the magnitude of the mining pressure in the mining pressure zone is directly proportional to the degree of support.

[0006] Optionally, before obtaining the first stress of the first coal pillar at the first moment of the first coal seam working face, the method further includes: obtaining mining information of the working face, wherein the mining information includes one or more of the following: coal seam burial depth, mining height, rock mechanics parameters, coal pillar size, and oblique angle between two adjacent working faces at the coal mine site; the working face is the first coal seam working face or the second coal seam working face; constructing a three-dimensional model of the working face using FLAC3D software, wherein the three-dimensional model is a virtual model of the working face; simulating coal mining operations using FLAC3D software and generating a cloud map, wherein the color in the cloud map corresponds one-to-one with the stress, and the depth of the color in the cloud map is directly proportional to the magnitude of the stress.

[0007] Optionally, obtaining the first stress of the first coal pillar of the first coal seam working face at a first moment includes: obtaining the first sub-stress of the first sub-coal pillar of the first sub-coal seam working face at the first moment, wherein the first sub-coal seam working face is a part of the first coal seam working face, the first sub-coal pillar is a coal pillar located in the first sub-coal seam working face, and the first sub-stress is obtained according to the color in the cloud map; obtaining the second sub-stress of the second sub-coal pillar of the second sub-coal seam working face at the first moment, wherein the second sub-coal seam working face is a part of the first coal seam working face, the second sub-coal pillar is a coal pillar located in the second sub-coal seam working face, and there is a coal seam with a triangular region between the first sub-coal seam working face and the second sub-coal seam working face. Before the second coal seam working face is mined, the first sub-coal pillar and the second sub-coal pillar transmit stress to the second coal seam working face, and the second sub-stress is obtained according to the color in the cloud map.

[0008] Optionally, the second time point includes a first sub-time point and a second sub-time point, where the first sub-time point is earlier than the second sub-time point. The second coal seam working face includes a third sub-coal seam working face and a fourth sub-coal seam working face. Coal is mined at the third sub-coal seam working face at the first sub-time point and at the fourth sub-coal seam working face at the second sub-time point. Obtaining the second stress of the second coal pillar of the second coal seam working face at the second time point includes: obtaining the third sub-stress of the third sub-coal pillar when mining the third sub-coal seam working face at the first sub-time point, wherein the third sub-coal pillar is a coal pillar located in the third sub-coal seam working face, and the distance between the third sub-coal seam working face and the oblique intersection point is directly proportional to the magnitude of the third sub-stress. The oblique intersection point is the first sub-coal pillar and the fourth sub-coal seam working face. The intersection point between the third sub-coal pillars, and the third sub-stress obtained according to the color in the cloud map; when mining the third sub-coal seam face at the first sub-time, the fourth sub-stress of the fourth sub-coal pillar is obtained, wherein the fourth sub-coal pillar is a coal pillar located in the fourth sub-coal seam face, and the distance between the fourth sub-coal seam face and the oblique intersection point is directly proportional to the magnitude of the fourth sub-stress, which is obtained according to the color in the cloud map; when mining the fourth sub-coal seam face at the second sub-time, the fifth sub-stress of the fourth sub-coal pillar is obtained, wherein the distance between the fourth sub-coal seam face and the oblique intersection point is directly proportional to the magnitude of the fifth sub-stress, which is obtained according to the color in the cloud map.

[0009] Optionally, before determining the mining pressure area based on the magnitude relationship between the first stress and the second stress, the method further includes: when mining the fourth sub-coal seam working face, obtaining the third stress of the fourth sub-coal seam working face, wherein the third stress is obtained based on the color in the cloud map, there are multiple third stresses, and the number of third stresses corresponds one-to-one with the distance between the fourth sub-coal seam working face and the oblique intersection point; constructing a stress curve based on the multiple third stresses, wherein the horizontal axis of the stress curve is the length of the fourth sub-coal seam working face, and the vertical axis of the stress curve is the stress value.

[0010] Optionally, before determining the stress zone based on the magnitude relationship between the first stress and the second stress, the method further includes: obtaining a first position of the first coal pillar; obtaining a second position of the second coal pillar; and determining a stress concentration region based on the first position and the second position, wherein stress concentration characterizes the stress superposition of at least two coal pillars, and the distance between the first position and the second position is proportional to the degree of stress concentration.

[0011] Optionally, determining the mining pressure region based on the magnitude relationship between the first stress and the second stress includes: determining the current region as a first mining pressure region when the first stress is less than the second stress, the difference between the first stress and the second stress is greater than a first difference, and the difference between the first stress and the second stress is less than a second difference, wherein the first difference is less than the second difference; and determining the current region as a second mining pressure region when the first stress is less than the second stress, and the difference between the first stress and the second stress is greater than or equal to the second difference, wherein the stress in the first mining pressure region is less than the stress in the second mining pressure region.

[0012] According to another aspect of this application, an apparatus for determining a mining pressure zone is provided, comprising: a first acquisition unit for acquiring a first stress of a first coal pillar of a first coal seam working face at a first moment, wherein the first coal pillar is a coal pillar located in the first coal seam working face, the first coal seam working face is a working face with a coal seam in a coal mine, and the first moment is any mining moment; a second acquisition unit for acquiring a second stress of a second coal pillar of a second coal seam working face at a second moment, wherein the first coal seam working face and the second coal seam working face are separated by a predetermined distance, the area between the first coal seam working face and the second coal seam working face is a triangular area, the first moment is earlier than the second moment, the second coal pillar is a coal pillar located in the second coal seam working face, and the first coal pillar and the second coal pillar are obliquely intersecting; a first determination unit for determining a mining pressure zone based on the magnitude relationship between the first stress and the second stress, wherein the difference between the first stress and the second stress is directly proportional to the magnitude of the mining pressure; and a second determination unit for determining the degree of support for the coal mine based on the mining pressure zone, wherein the magnitude of the mining pressure in the mining pressure zone is directly proportional to the degree of support.

[0013] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform any of the methods for determining the mining pressure area.

[0014] According to another aspect of this application, a computer program product is provided, including a computer program that, when executed by a processor, implements any of the methods for determining the mining pressure zone.

[0015] By applying the technical solution of this application, the stress of the working face is obtained at different times: the first time is before the working face is mined, and the second time is after the working face is mined. Therefore, for a triangular oblique coal pillar, the evolution law of stress can be obtained based on the change of its stress. Then, based on the magnitude of the stress, the area of ​​the working face that is prone to strong or weak mining pressure can be determined. This fills the technical gap in the existing technology for the study of mining pressure in triangular areas, thereby improving the mining efficiency of the working face of the triangular oblique coal pillar. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1 A hardware structure block diagram of a mobile terminal for performing a method for determining a mining pressure zone according to an embodiment of this application is shown;

[0018] Figure 2 A flowchart illustrating a method for determining a mining pressure zone according to an embodiment of this application is shown.

[0019] Figure 3 A schematic diagram showing the positional relationship of the working surfaces is provided.

[0020] Figure 4 A schematic diagram of the simulated coal seam of the first coal seam working face is shown;

[0021] Figure 5 A schematic diagram of the simulated coal seam of the constructed second coal seam working face is shown;

[0022] Figure 6 A schematic diagram showing the vertical stress distribution around the triangular coal pillar in the first coal seam working face is shown.

[0023] Figure 7 A schematic diagram showing the vertical stress distribution of the coal seam in the second coal seam working face caused by the triangular coal pillar is shown.

[0024] Figure 8 A schematic diagram of the stress distribution in the 0m coal pillar of the oblique section during the mining of the third sub-coal seam is shown.

[0025] Figure 9 A schematic diagram of the stress distribution in the 30m coal pillar of the entry section during the mining of the third sub-coal seam is shown.

[0026] Figure 10 A schematic diagram of the stress distribution in a 5m coal pillar during the mining of the third sub-coal seam is shown.

[0027] Figure 11A schematic diagram of the stress distribution in the 80m coal pillar during the mining of the third sub-coal seam is shown.

[0028] Figure 12 A schematic diagram of the stress distribution of the coal pillar in the fourth sub-coal seam working face section when the third sub-coal seam working face passes through the inclined coal pillar is shown;

[0029] Figure 13 A schematic diagram of the stress concentration core zone of a triangular coal pillar is shown;

[0030] Figure 14 A schematic diagram of the stress distribution 180m from the oblique intersection point during the mining of the fourth sub-coal seam is shown.

[0031] Figure 15 A schematic diagram of the stress distribution 100m from the oblique intersection point during the mining of the fourth sub-coal seam is shown.

[0032] Figure 16 A schematic diagram of the stress distribution at a distance of 60m from the oblique intersection point during the mining of the fourth sub-coal seam is shown.

[0033] Figure 17 A schematic diagram of the stress distribution 40m from the oblique intersection point during the mining of the fourth sub-coal seam is shown.

[0034] Figure 18 A schematic diagram of the stress distribution at a distance of 0m from the oblique intersection point is shown during the mining of the fourth sub-coal seam.

[0035] Figure 19 A schematic diagram of the stress distribution at a distance of 90m from the oblique intersection point during the mining of the fourth sub-coal seam is shown.

[0036] Figure 20 A schematic diagram showing the distribution law of the advance support pressure in the fourth sub-coal seam working face is shown;

[0037] Figure 21 A schematic diagram showing the stress distribution of the coal pillar in the working face section of the fourth sub-coal seam at different advance distances is shown;

[0038] Figure 22 A schematic diagram showing the evolution of stress distribution in the coal pillar of the advanced section of the working face is presented.

[0039] Figure 23 A schematic diagram showing the separation of superimposed stress at the oblique intersection of the coal face and stress in the coal column section is shown.

[0040] Figure 24 A schematic diagram is shown showing the deflection of stress from the oblique coal pillar to the section coal pillar near the end of the oblique intersection point;

[0041] Figure 25 A schematic diagram of high-stress superposition is shown when the oblique intersection point is located in the coal pillar of the section;

[0042] Figure 26 A schematic diagram showing the stress distribution of the coal pillar in the working face section of the fourth sub-coal seam under the oblique coal pillar is shown;

[0043] Figure 27 A schematic diagram of the reinforced support zones for the roadway is shown;

[0044] Figure 28 A structural block diagram of a device for determining a mining pressure zone according to an embodiment of this application is shown.

[0045] The above figures include the following reference numerals:

[0046] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device. Detailed Implementation

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0049] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0050] As described in the background section, the prior art suffers from poor mining efficiency due to the inability to determine the mining pressure of the working face of the triangular oblique coal pillar. To address this problem, embodiments of this application provide a method, apparatus, computer-readable storage medium, and computer program product for determining the mining pressure area.

[0051] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0052] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a method of determining a mining pressure area according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0053] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the device information display method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0054] This embodiment provides a method for determining a mining pressure area that runs on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0055] Figure 2 This is a flowchart illustrating a method for determining a mining pressure zone according to an embodiment of this application. Figure 2 As shown, the method includes the following steps:

[0056] Step S201: Obtain the first stress of the first coal pillar of the first coal seam working face at the first moment, wherein the first coal pillar is a coal pillar located in the first coal seam working face, the first coal seam working face is a working face with a coal seam in a coal mine, and the first moment is any moment of coal mining.

[0057] Specifically, this scheme takes the 31109 working face of a coal mine, which crosses an overlying triangular oblique coal pillar, as an example. It elaborates on the main technical content of this scheme, providing a detailed explanation of the selection and analysis methods for key stress slice cloud maps and characteristic curves. It derives the criteria for delineating the stress rise zone, significant influence zone, peak position, and stress reduction zone in the near-face section of the coal pillar roadway. All the patterns and characteristics revealed in this scheme fall within its protection scope.

[0058] Specifically, such as Figure 3 As shown, the first coal seam working face of this coal mine (2 in this plan) -2 The coal seam working faces include working faces 22107, 22109, and 22119. The first stress is the stress value of the first coal seam working face.

[0059] Step S202: Obtain the second stress of the second coal pillar of the second coal seam working face at the second time, wherein the first coal seam working face and the second coal seam working face are separated by a predetermined distance, the area between the first coal seam working face and the second coal seam working face is a triangular area, the first time is earlier than the second time, the second coal pillar is a coal pillar located in the second coal seam working face, and the first coal pillar and the second coal pillar are obliquely intersecting.

[0060] Specifically, the first coal seam working face of the coal mine (2 in this plan) -2 The coal seam at the first working face has been mined out. The next step is to mine the second working face below (the third working face in this plan). -1The average distance between the two coal seams is 40m. The second coal seam working face includes working faces 31109 and 31206. The second stress is the stress value of the second coal seam working face. -1 The 31109 coal seam working face has a width of 285m, an advance distance of 2715m, a mining height of 3.6m, a burial depth of approximately 300m, and a rated working resistance of 18000kN for the working face supports. The upper part of the 31109 working face is... -2 The goaf areas of coal seams 22109 and 22107 are bordered by solid coal to the north and the 31206 goaf area to the south (see...). Figure 3 ). Figure 3 2 is shown in the figure -2 Coal seam working face roadways and 3 -1 Coal seam working face roadway. When the 31109 working face passes over the overlying triangular coal pillar, the return airway is severely deformed and damaged.

[0061] Step S203: Determine the mining pressure area based on the relationship between the first stress and the second stress, wherein the difference between the first stress and the second stress is directly proportional to the magnitude of the mining pressure.

[0062] Specifically, the mechanism of mine pressure manifestation and the area of ​​mine pressure can be determined based on the magnitude and variation of stress during coal mining operations.

[0063] Step S204: Determine the degree of support for the coal mine based on the aforementioned mining pressure area, wherein the magnitude of the mining pressure in the aforementioned mining pressure area is directly proportional to the degree of support.

[0064] Specifically, once the mining pressure area is identified, the scope requiring enhanced support and the timing for supporting the coal mine can be determined, providing a scientific basis for determining the correct enhanced support strategies.

[0065] This embodiment obtains the stress of the working face at different times: the first time is before mining and the second time is after mining. Therefore, for a triangular oblique coal pillar, the evolution law of stress can be obtained based on its stress changes. Then, based on the stress magnitude, the areas of the working face that are prone to strong or weak mining pressure can be determined. This fills the technical gap in the existing technology for the study of mining pressure in triangular areas, thereby improving the mining efficiency of the working face of the triangular oblique coal pillar.

[0066] Because the intersection position of the oblique coal pillar and the coal face changes continuously as the working face advances, the presence of an oblique intersection between a triangular coal pillar and a section of the lower coal seam working face can lead to significant mining pressure manifestations at the working face, especially in sections of the return airway. This has a significant impact on the stability of the working face roadway, and in severe cases, can cause roof collapses and compromise the safety of the working face mining. For triangular oblique coal pillars, in addition to the changing position of the coal face and the coal wall, the area of ​​the triangular coal pillar acting above the section of the lower coal seam also changes, resulting in more pronounced regional characteristics of mining pressure manifestations during the mining of the lower coal seam. Therefore, this scheme proposes a method for determining the strong mining pressure area in a shallowly buried, closely spaced coal seam working face under a triangular oblique coal pillar, revealing the strong mining pressure mechanism of triangular oblique coal pillar mining, and proposing a method for determining the strong mining pressure area in a coal seam working face under similar conditions, thereby improving the safe and efficient mining of the working face.

[0067] In the specific implementation process, before obtaining the first stress of the first coal pillar at the first moment of the first coal seam working face, the above method also includes the following steps: obtaining mining information of the working face, wherein the mining information includes one or more of the following: coal seam burial depth, mining height, rock mechanics parameters, coal pillar size, and oblique angle between two adjacent working faces at the coal mine site, wherein the working face is the first coal seam working face or the second coal seam working face; constructing a three-dimensional model of the working face using FLAC3D software, wherein the three-dimensional model is a virtual model of the working face; simulating coal mining operations using FLAC3D software and generating a cloud map, wherein the color in the cloud map corresponds one-to-one with the stress, and the depth of the color in the cloud map is directly proportional to the magnitude of the stress.

[0068] In this scheme, FLAC3D three-dimensional numerical simulation software is used to construct a three-dimensional model to restore the size and environment of the triangular coal pillar as much as possible, thereby simulating coal mining operations, restoring the working face of the coal mining, and improving the accuracy of subsequent stress analysis results.

[0069] Specifically, the above-described embodiments are used for the construction of a three-dimensional model. The FLAC3D three-dimensional numerical simulation software is used to construct a three-dimensional numerical calculation model based on the mining conditions such as the burial depth of the nearby coal seams, the mining height of each coal seam, the lithology and mechanical parameters of the overlying strata, the size of the overlying triangular coal pillar, and the oblique angle. Sufficient boundary conditions and constraints (i.e., the hierarchical relationship between the working face boundary and the coal seam when constructing the virtual model) are considered.

[0070] Specifically, after constructing the 3D model, the next step is to excavate the 3D model, i.e., simulate coal mining operations. Based on the actual mining conditions and computer processing capabilities, a reasonable excavation step distance is designed (generally 5-10 meters, but can be determined according to the actual coal mining operations on site). A comparative analysis is then conducted with similar working faces on site, and the numerical simulation parameters are calibrated (i.e., geological parameters are calibrated, including compressive strength, tensile strength, shear strength, internal distance, etc., to maintain consistency with actual coal mining conditions), followed by excavation analysis of the study area.

[0071] In addition, in this scheme, after the upper coal seam is mined, the stress distribution law of the lower coal seam caused by the triangular coal pillar can be obtained: after the upper coal seam is mined and before the lower coal seam is mined, based on the stress slice cloud map of the roof of different layers of the upper and lower coal seams, the stress concentration degree of the section coal pillar before and after the upper coal seam is mined can be compared and analyzed, and the size of the influence range of the triangular coal pillar and the degree of stress concentration can be obtained.

[0072] Specifically, based on the borehole strata and working face layout in the study area, and the dimensions and oblique angles of the triangular coal pillars, a FLAC3D model was constructed. The model was built in regional sections to facilitate mesh generation and model excavation. This ensured that the boundary conditions and the actual mining area were not limited by the boundary conditions or the mining area itself. First, the upper coal seam was mined, forming the remaining triangular coal pillar area and the stress characteristics after the oblique coal pillars were mined. Then, excavation simulation was performed according to actual mining conditions. The model first underwent a 2-ton mining run. -2 Coal seam, then mined 3 -1 The study focuses on the impact of the obliquely intersecting coal pillars left over from the upper part of the coal seam on the stress of the roadway and coal pillars in the lower coal seam during the mining of the 31206 and 31109 working faces. The coal pillars are 20m wide, with an oblique angle of 22°, and their projected length onto the 31206 working face is 53m. Figure 4 and Figure 5 As shown.

[0073] The main innovation of this scheme lies in its ability to accurately reproduce the geometric dimensions and stress environment of a triangular coal pillar, simulating real mining conditions. It primarily focuses on simulating the stress environment of working faces in shallowly buried, closely spaced coal seams, thereby improving the accuracy of the analysis results.

[0074] In the specific implementation process, obtaining the first stress of the first coal pillar of the first coal seam working face at the first moment can be achieved through the following steps: obtaining the first sub-stress of the first sub-coal pillar of the first sub-coal seam working face at the aforementioned first moment, wherein the first sub-coal seam working face is a part of the working face of the first coal seam working face, and the first sub-coal pillar is a coal pillar located in the working face of the first sub-coal seam working face, and the first sub-stress is obtained according to the color in the aforementioned cloud map; obtaining the second sub-stress of the second sub-coal pillar of the second sub-coal seam working face at the aforementioned first moment, wherein the second sub-coal seam working face is a part of the working face of the first coal seam working face, and the second sub-coal pillar is a coal pillar located in the working face of the second sub-coal seam working face, wherein there is a triangular region between the first sub-coal seam working face and the second sub-coal seam working face, and before the second coal seam working face is mined, the first sub-coal pillar and the second sub-coal pillar transmit stress to the second coal seam working face, and the second sub-stress is obtained according to the color in the aforementioned cloud map.

[0075] In this scheme, the first coal seam working face is the working face during one mining operation. During one mining operation, the stress changes of the first sub-coal pillar and the second sub-coal pillar can be determined by the color changes in the cloud map, thereby determining the stress characteristics of the coal pillar more accurately and the evolution law of the stress of the coal pillar during the mining operation more accurately.

[0076] Specifically, in the above embodiments, the evolution law of the support pressure during primary mining of the lower coal seam working face under the triangular oblique coal pillar is analyzed. Due to the action of the overlying triangular oblique coal pillar, there must be an oblique section with the section coal pillar of the lower coal seam working face. As the size of the overlying triangular oblique coal pillar decreases, the stress of the triangular oblique coal pillar overlaps with the section coal pillar of the current coal seam, resulting in significant stress concentration. Taking the intersection of the triangular oblique coal pillar and the section coal pillar of the working face during primary mining, the evolution law of the working face's advanced support stress, section coal pillar stress, and triangular oblique coal pillar tip stress during the stage of entering and exiting this intersection is analyzed. Based on the evolution law of these three factors, the area where the working face's mine pressure manifests is determined, focusing on the stress rise zone, significant influence zone, peak position, and stress reduction zone of the roadway near the section coal pillar of the working face, providing theoretical support for the working face roadway support. Tip stress refers to the direction of the smallest acute angle of the triangle; the tip represents this small local area.

[0077] Specifically, 2 -2 After coal seam mining, the vertical stress distribution around the remaining triangular coal pillar is as follows: Figure 6As shown, the high-pressure zone around the triangular coal pillar is mainly distributed in the coal pillars of the 21109 working face (first sub-coal seam working face) and the 22119 working face (second sub-coal seam working face), where the concentrated stress is relatively high. The 21109 coal pillar, located on the hypotenuse of the triangular coal pillar, has the highest stress, with a support pressure zone width of 40m and a peak stress of 45MPa, which is 7.7 times the original rock stress. The 22119 working face coal pillar, located on the lower right-angle side, has a support pressure zone width of 50m, a peak stress of 35MPa, and a peak stress coefficient of 6.0.

[0078] 3 -1 Before coal seam mining, the maximum downward stress transmitted from the hypotenuse of the overlying triangular coal pillar (coal pillar in section 21109) was 15 MPa, while the peak downward stress transmitted from the straight side of the triangular coal pillar (coal pillar in section 22119) was 12 MPa. The peak stress decreased by 2 / 3. Figure 7 As shown.

[0079] In the specific implementation process, the aforementioned second time moment includes a first sub-time moment and a second sub-time moment, the aforementioned first sub-time moment is earlier than the aforementioned second sub-time moment, the aforementioned second coal seam working face includes a third sub-coal seam working face and a fourth sub-coal seam working face, coal is mined at the aforementioned third sub-coal seam working face at the aforementioned first sub-time moment, and coal is mined at the aforementioned fourth sub-coal seam working face at the aforementioned second sub-time moment, obtaining the second stress of the second coal pillar of the second coal seam working face at the second time moment can be achieved through the following steps: when mining coal at the aforementioned third sub-coal seam working face at the aforementioned first sub-time moment, obtaining the third sub-stress of the third sub-coal pillar, wherein the aforementioned third sub-coal pillar is a coal pillar located in the aforementioned third sub-coal seam working face, the distance between the aforementioned third sub-coal seam working face and the oblique intersection point is directly proportional to the magnitude of the aforementioned third sub-stress, the aforementioned oblique intersection point is... The intersection point between the first sub-coal pillar and the aforementioned third sub-coal pillar, the aforementioned third sub-stress is obtained according to the color in the aforementioned cloud map; when mining the aforementioned third sub-coal seam working face at the aforementioned first sub-time, the fourth sub-stress of the fourth sub-coal pillar is obtained, wherein the aforementioned fourth sub-coal pillar is a coal pillar located in the aforementioned fourth sub-coal seam working face, the distance between the aforementioned fourth sub-coal seam working face and the oblique intersection point is directly proportional to the magnitude of the aforementioned fourth sub-stress, the aforementioned fourth sub-stress is obtained according to the color in the aforementioned cloud map; when mining the aforementioned fourth sub-coal seam working face at the aforementioned second sub-time, the fifth sub-stress of the aforementioned fourth sub-coal pillar is obtained, wherein the distance between the aforementioned fourth sub-coal seam working face and the oblique intersection point is directly proportional to the magnitude of the aforementioned fifth sub-stress, the aforementioned fifth sub-stress is obtained according to the color in the aforementioned cloud map.

[0080] In this scheme, the second coal seam working face is the working face during the second mining period. During the second mining period, the stress changes of the third and fourth sub-coal pillars can be determined by the color changes in the cloud map, thereby determining the stress characteristics of the coal pillars more accurately and the evolution law of the stress of the coal pillars during the mining period more accurately.

[0081] Specifically, in the above embodiments, the evolution law of the support pressure during secondary mining of the lower coal seam working face is analyzed. Influenced by the overlying triangular oblique coal pillar, by selecting the secondary mining stage of the lower coal seam working face section coal pillar, the evolution law of the three factors—advanced support stress in the middle of the intersection of the working face entry and exit point (the intersection of the secondary mining face roadway and the triangular coal pillar), section coal pillar stress, and the stress at the tip of the triangular oblique coal pillar—is also analyzed. This yields the influence range and peak value evolution characteristics of the support stress, the stress superposition and deflection near the peak value region, and the influence range and magnitude of the stress peak value. The mining pressure manifestation area of ​​the working face near the section coal pillar side roadway during the secondary mining stage is given, along with the location and peak value evolution characteristics of the stress rise zone, significant influence zone, peak value position, and stress reduction zone. This provides a theoretical basis for advanced reinforcement support and monitoring and early warning of the coal seam working face roadway.

[0082] Specifically, the following details the evolution of support pressure during mining under a triangular oblique coal pillar. The first aspect is the stress evolution of the section coal pillar (third sub-coal pillar) during the mining of the 31206 working face (the third sub-coal seam working face). During the cross-coal pillar mining process of the 31206 working face, 3... -1 The vertical stress distribution pattern around the coal seam working face and in the coal pillar section is as follows: Figure 8 , Figure 9 , Figure 10 and Figure 11 As shown, the stress distribution variation law of the coal pillar (fourth sub-coal pillar) section along the 31109 working face (fourth sub-coal seam working face) is as follows: Figure 12 As shown ( Figure 12 The horizontal coordinate 0 corresponds to the left boundary of the coal pillar in the oblique section of the 22109 working face, and has the following characteristics and patterns:

[0083] ① After the 31206 working face was mined, the stress in the coal pillar of the 31109 working face section to the side began to rise. When the coal pillar of the 31109 working face section was 170m away from the overlying oblique section, the peak stress of the coal pillar of the 31109 working face section was 23.6 MPa, which was 1.5 times that before mining, and it was located 80m behind the working face.

[0084] ② When the working face advances to 70m away from the coal pillar of the oblique section, the maximum stress of the coal pillar in the 31109 working face section is 37.1MPa. It is located 120m behind the working face, and the peak stress at the corresponding coal wall of the working face is 17.5MPa.

[0085] ③ When the working face advances to the corresponding distance of 0m from the overlying oblique coal pillar, the stress of the coal pillar in the 31109 working face section increases significantly. The stress peak area shifts from the middle of the goaf to the bottom of the oblique section coal pillar, reflecting the superposition effect of the working face's advance support pressure and the stress of the overlying oblique coal pillar.

[0086] ④ When the coal pillar is 5m long, the maximum stress in the coal pillar of section 31109 is 49.8MPa. After the coal pillar is removed from the working face, the concentrated stress of the overlying oblique coal pillar and the peak stress of the coal pillar in the section behind the 31109 working face gradually begin to superimpose, and the peak stress continues to rise.

[0087] ⑤ After the coal pillar reaches 80m from the working face, the maximum stress in the coal pillar of the 31109 working face section is 60MPa, with the peak stress located directly below the upper inclined coal pillar. At this point, the concentrated stress in the inclined coal pillar is completely superimposed with the support pressure behind the 31109 working face, and the concentrated stress no longer increases thereafter.

[0088] Regarding the failure mechanism of the roadway in the superimposed stress zone of the coal pillar section, after the mining of the 31206 working face, the lateral support pressure and the concentrated stress transmitted by the overlying triangular oblique coal pillar form a superimposed stress in the coal pillar of the 31109 section. The stress peak zone is centered on the oblique intersection point of the coal pillar and extends outward by 30m. Figure 12 From 80m (horizontal axis) to 210m inward ( Figure 12 The horizontal axis is -160m, and the length is 240m (including the 50m oblique section coal pillar length).

[0089] The length of the peak stress region corresponds to the measured length of the severely damaged section of the roadway in the 32106 working face, which is 241m (see...). Figure 12 It is evident that after the mining of the 32106 working face, the triangular coal pillar area decreased, and the stress at the tip of the triangle became more concentrated. The stress transmitted by the triangle overlapped with the lateral support pressure of 32106, resulting in an increase in the stress of the coal pillar in the 31109 section, which corresponds to the deformation and damage of the 32106 main haulage roadway in this section.

[0090] For the stress core area of ​​the triangular coal pillar, after the mining of the 31206 working face, the range of the triangular coal pillar above the 31109 working face decreased, and the concentrated stress of the coal pillar further increased. This manifested as increased stress transmission to the coal seam of the 31109 working face, and the location of the maximum stress also changed. The stress under the coal pillar in the 22109 section of the hypotenuse of the triangular coal pillar increased from 15 MPa ( Figure 6 The pressure increased to 25 MPa. Figure 11 The stress in section 31109 of the coal pillar under the straight side of the triangular coal pillar is determined by its location, and the stress value is determined by... Figure 11 As shown.

[0091] After the 31206 working face was mined, the peak pressure zone corresponding to the superimposed coal pillar in the 31109 working face section had a straight side length of 210m (total length 240m minus 30m outside the coal pillar), and a corresponding triangular coal pillar width (including the coal pillar in the oblique section) of 84m, approximately twice the width of the support pressure zone. That is, in the triangular area where the width of the triangular coal pillar is twice the width of the support pressure zone, the superimposed support pressure from both sides is most significant, making it the stress core area of ​​the triangular coal pillar. This section of the roadway will be significantly affected and deformed, such as... Figure 13 As shown.

[0092] The stress core zone of the triangular coal pillar is transmitted downward to the superimposed stress peak zone of the coal pillar in the 31109 working face section, and extends outward with a width of about 30m. Based on the 40m thickness of the interlayer rock, the stress transmission angle of the peak zone is about 37°.

[0093] Secondly, the stress evolution law of the 31109 working face under the influence of the overlying triangular oblique coal pillar is introduced. During the mining of the 31109 working face, the stress evolution law of the secondary mining support of the coal pillar in the 31109 section is as follows: Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 , Figure 19 and Figure 20 As shown (the oblique intersection point refers to the intersection of the left boundary of the overlying 22109 section coal pillar and the lower 31109 section coal pillar).

[0094] The evolution law of peak pressure under the advance support of the coal face mainly includes the following laws:

[0095] ① Initial Double-Peak Characteristics: During the mining of the working face through the oblique triangular coal pillar, before advancing to 100m from the oblique point, the peak value of the working face's advance support pressure exhibits a double-peak distribution (one corresponding to the coal pillar position in the oblique section, and the other to the working face end position), and increases with the advancement of the working face, overlapping and deflecting towards the end. Within the range of 60~180m from the oblique point, two peak values ​​(maximum points) can be clearly seen at the x-coordinate of 0 and at a certain x-coordinate position, see [see details]. Figure 20 Starting at 60m, the peak value is basically monotonically decreasing, without a maximum value, exhibiting a single peak.

[0096] like Figure 20 As shown, when the working face advances to 160m from the oblique intersection point, the coal pillar in the overlying oblique intersection section is located approximately 80m from the lower end of the working face coal wall, resulting in a stress peak at this location. The magnitude of this peak, similar to the peak bearing pressure at the lower end of the working face, is approximately 38MPa. Figure 20 As shown.

[0097] When the working face advances to 100m from the intersection point, as the triangular coal pillar area decreases, the stress in the coal pillar of the oblique section begins to superimpose with the support pressure at the end of the working face, resulting in a double-peak increase that shifts towards the end. The peak stress corresponding to the coal pillar in the oblique section rises to 40MPa, and the stress at the end rises to 45MPa.

[0098] ② The double peaks merge into a single peak: When the working face advances to 60m from the oblique intersection point (the width of the coal pillar is 1 times the width of the support pressure zone), the double peaks completely merge into a single peak, located at the end of the coal seam working face.

[0099] ③ The maximum peak value is located at the oblique intersection point: As the working face advances, the single peak stress continues to rise. When the working face advances to the oblique intersection point, the single peak stress reaches a maximum of 57MPa, which is 2.7 times that before superposition.

[0100] ④ Rapid decline of single peak after coal pillar exit: When the working face advances to 20m past the intersection point and is located in the center of the oblique coal pillar, the peak stress is 54MPa. 50m past the intersection point is the boundary of the triangular coal pillar area, and the advance support pressure drops rapidly to 38MPa. 30m after coal pillar exit: As the working face advances, the stress of the oblique coal pillar in the goaf gradually decreases and stabilizes at around 10MPa.

[0101] ⑤ Effect of falling off the triangular oblique coal pillar: 90m past the intersection point of the working face and 40m from the coal pillar, the working face is freed from the influence of the triangular oblique coal pillar, and the end stress recovers to 21MPa.

[0102] Overall, as the 31109 working face advanced to 160m from the oblique intersection point (entering the triangular coal pillar core area), the advance support pressure of the coal seam working face exhibited a double-peak pattern due to the influence of the coal pillar in the oblique intersection section. As the working face advanced, the double peaks overlapped, and the peak stress continuously increased, evolving into a single-peak pattern at the end. After the working face exited the coal pillar, the single peak rapidly decreased, and gradually returned to normal after 40m of coal pillar exit.

[0103] Third, the stress evolution law of the coal pillar in the 31109 working face section is introduced. According to the above analysis, after the mining of the 31206 working face, due to the superposition of the overlying triangular coal pillar core area and the lateral support pressure of the working face, a stress concentration zone of about 240m was formed on the coal pillar in the 31109 working face section, which has led to the deformation and damage of the main transport roadway in this area.

[0104] After the 31109 working face is mined, the area of ​​the overlying triangular coal pillar will gradually decrease. The concentrated stress of the overlying coal pillar will overlap with the pressure of the working face's advance support, leading to a further increase in the stress of the coal pillar in the advance section, causing deformation and failure of the 31109 return air roadway. Therefore, it is necessary to reveal the stress evolution law of the coal pillar in the advance section of the working face to provide a basis for roadway support design.

[0105] During the mining of the 31109 working face, the stress distribution of the coal pillar in different positions of the working face at different distances from the oblique intersection point is as follows: Figure 21 As shown, the evolution law of the advance support pressure at different advance distances of the working face is as follows: Figure 22 As shown, the following pattern exists:

[0106] ① Peak stress location: At different advance distances of the working face, the peak stress point of the section coal pillar is always located at the intersection of the section coal pillar and the overlying triangular oblique coal pillar, such as... Figure 21 As shown.

[0107] ② Peak stress stabilization section: After the working face is mined, before advancing to 70m from the oblique intersection point, the peak stress of the coal pillar in the 31109 working face section is around 80MPa, which is 1.4 times that before mining.

[0108] ③ Peak stress rising stage: After the work progresses to 70m from the oblique intersection point, the peak stress of the coal pillar in the section begins to rise continuously.

[0109] ④ Maximum peak stress point: When advancing to the oblique intersection point, the advance support pressure reaches its maximum, which is 89MPa, 1.56 times that before mining.

[0110] ⑤ Peak stress reduction stage: After the working face passes the oblique intersection point, the peak stress of the coal pillar in the advanced section of the working face begins to decrease, and the maximum stress corresponds to the position of the coal wall of the working face; after the coal pillar is 150m from the working face, the advanced stress drops to 29MPa.

[0111] ⑥ Stress peak zone range: Based on the benchmark that the coal pillar stress corresponding to the roadway failure zone after the mining of the 31206 working face is greater than 48MPa, the range of the stress peak zone of the coal pillar in the section after the mining of the 31109 working face is determined. This range is centered on the oblique intersection point, extending 220m inward to 120m outward. Figure 22 The horizontal axis is 50m-390m, totaling 340m. It can be seen that after the second mining, the range of the peak stress zone of the coal pillar in the section increased by 100m, and the peak value increased by 1.57 times compared with the first mining.

[0112] To ensure roadway safety, the roadway within a 340m radius of the overlying oblique coal pillar overlap area should be reinforced before mining.

[0113] The main innovation of the above scheme lies in analyzing the combined effects of the pre-support stress, section coal pillar stress, and triangular oblique coal pillar tip stress during the primary and secondary mining of the lower coal seam. It provides planar and cross-sectional views of stress cloud diagrams at key locations during the transition from the lower coal seam to and from the intersection of the triangular coal pillar and the section coal pillar. Through characteristic analysis of the superimposed stress cloud diagram area and the variation of the stress concentration factor with the transition from the coal pillar, the stress characteristics during the transition from the triangular coal pillar are derived. This provides ideas and theoretical basis for the analysis of similar situations.

[0114] To further provide a basis for roadway support, before determining the mining pressure zone based on the magnitude relationship between the first stress and the second stress, the method further includes the following steps: When mining the fourth sub-coal seam working face, obtain the third stress of the fourth sub-coal seam working face, wherein the third stress is obtained based on the color in the cloud map, and there are multiple third stresses, with the number of third stresses corresponding one-to-one with the distance between the fourth sub-coal seam working face and the oblique intersection point; based on the multiple third stresses, construct a stress curve, wherein the horizontal axis of the stress curve is the length of the fourth sub-coal seam working face, and the vertical axis of the stress curve is the stress value.

[0115] In this scheme, a stress curve can be constructed after obtaining the third stress. This stress curve can clearly represent the changes and evolution of stress, providing a basis for subsequent roadway support.

[0116] Specifically, the stress curve can be Figure 21 or Figure 22 The curve graph.

[0117] In some embodiments, before determining the stress zone based on the magnitude relationship between the first stress and the second stress, the method further includes the following steps: obtaining a first position of the first coal pillar; obtaining a second position of the second coal pillar; and determining a stress concentration region based on the first position and the second position, wherein stress concentration characterizes the stress superposition of at least two coal pillars, and the distance between the first position and the second position is proportional to the degree of stress concentration.

[0118] In this scheme, the stress in the coal pillar may be superimposed during the mining of the working face, which will cause the stress to increase. Therefore, the stress concentration area can be identified to provide a theoretical basis for subsequent roadway support.

[0119] Specifically, based on the aforementioned numerical simulation analysis, the characteristics of concentrated stress superposition during the mining process under a triangular coal pillar can be derived as follows:

[0120] ① In the triangular region of a triangular coal pillar, as you get closer to the apex, the distance between the two sides of the triangle shortens, and the supporting pressure on both sides will gradually overlap, resulting in a concentrated stress zone at the triangular end.

[0121] ②When one side of the triangular coal pillar is parallel to and superimposed on the coal pillar of the lower coal seam section, a concentrated stress zone will be formed in the section coal pillar.

[0122] ③ When the coal pillar in the working face section intersects obliquely with the upper triangular coal pillar, the concentrated stress at the end of the oblique triangle and the concentrated stress in the coal pillar section will be superimposed, resulting in higher concentrated stress.

[0123] ④ When the hypotenuse of the triangular coal pillar intersects the coal wall of the working face at an oblique angle, the stress at the triangular end of the intersection point overlaps with the advance support pressure of the coal wall, forming a superimposed stress zone that moves with the advancement of the working face. Figure 23 , Figure 24 , Figure 25 ).

[0124] ⑤ When the working face advances to the point where the overlying triangular coal pillar end area overlaps with the coal pillar of the lower coal seam working face section ( Figure 23 , Figure 24 , Figure 25 There is a triple superposition of end zone stress, section coal pillar stress, and advance support pressure.

[0125] In summary, during the mining of the working face through triangular oblique coal pillars, there will be a moving stress zone of overlapping oblique coal pillars in the coal face, which may cause coal wall spalling and increased support load. When the oblique point is located near the lower end, the concentrated stress will continue to increase, leading to strong mine pressure at the lower end and difficulties in roadway support.

[0126] In some embodiments, the mining pressure zone is determined based on the magnitude relationship between the first stress and the second stress. This can be achieved through the following steps: when the first stress is less than the second stress, the difference between the first stress and the second stress is greater than the first difference, and the difference between the first stress and the second stress is less than the second difference, the current area is determined as the first mining pressure zone, wherein the first difference is less than the second difference; when the first stress is less than the second stress, and the difference between the first stress and the second stress is greater than or equal to the second difference, the current area is determined as the second mining pressure zone, wherein the stress in the first mining pressure zone is less than the stress in the second mining pressure zone.

[0127] In this scheme, after determining the magnitude and evolution of stress under two mining conditions, the region of mine pressure in the roadway of the working face can be identified. The mine pressure in different regions is different, and the scope and timing of support can then be determined based on the magnitude of the mine pressure in the region.

[0128] Specifically, the impact of triangular coal pillars on the working face and roadways of the lower coal seam is mainly manifested through the concentrated stress on the coal pillars in the adjacent sections. Due to the combined effects of the overlying triangular coal pillars, the pre-support stress, the stress in the adjacent coal pillar section, and the stress at the tip of the triangular oblique coal pillar, the mine pressure manifestation is most pronounced in the roadways near the adjacent coal pillars of the lower coal seam working face. The stress changes in the adjacent coal pillar section before and after mining are as follows: Figure 26 As shown.

[0129] It can be seen that before the lower coal seam is mined, the stress transmitted by the triangular coal pillar is within 15 MPa, which is about 2.2 times the original rock stress.

[0130] After the 31206 working face was mined, under the action of the upper triangular coal pillar, the stress in the coal pillar of the working face section increased to four times that before mining and 8.8 times that of the original rock stress, with an affected range of up to 240m. The peak point was located at the overlap of the upper and lower coal pillar sections. Practice has shown that the roadway deformation corresponding to this affected range is relatively large, and the damage is most severe near the oblique intersection point.

[0131] After the second mining operation of the 31109 working face, the roadway is mainly affected by the support pressure in front of the coal face and the superimposed stress of the inclined coal pillars. Before the working face advances to the point where the inclined coal pillars intersect with the section coal pillar, the stress in the section coal pillar will again be superimposed by the advance support pressure of the working face. When the working face advances to the intersection of the inclined coal pillar and the section coal pillar, the section coal pillar will bear the triple superposition of the stress from the overlying inclined coal pillar, the advance support pressure of the working face, and the stress of the section coal pillar itself, resulting in higher concentrated stress and a wider impact range. Due to the second mining operation, the stress in the advanced section coal pillar increases to 1.57 times that of the first mining operation, and is 6 times that before the mining operation, expanding the high-stress zone to 340m.

[0132] Therefore, before the secondary mining of the triangular oblique coal pillar in the 31109 working face, the return airway needs to be reinforced with support. The reinforced self-supporting section should focus on the area near the oblique intersection of the coal pillars, extending from 220m before the intersection to 120m after (70m after coal pillar exit), a total range of 340m. Because the stress in the coal pillar of the 31109 working face continuously increases from 220m away from the left boundary of the coal pillar overlap area, reaching its peak near the intersection point, the working face begins to enter the stress core zone of the triangular coal pillar, which is 50m long. Within 70m after exiting the stress core zone, the coal pillar is also in a high-stress state, belonging to the stress influence zone.

[0133] Based on the above analysis, the main cause of roadway deformation and failure is the high stress formed by the overlapping of triangular coal pillars in the adjacent sections of the roadway, a phenomenon verified by the mining practice of the 31206 working face. Therefore, before secondary mining of the section coal pillars caused by the triangular oblique coal pillar mining in the 31109 working face, it is necessary to strengthen the support of the return airway in advance. Figure 26 and Figure 27 Based on the spatial relationship of the oblique dimensions of the coal pillars, a reinforced support area for the 31109 working face roadway was proposed, and the reinforced support range of 360m was given, such as... Figure 27 As shown in the diagram. The 50m area before and after the intersection point is the key support zone.

[0134] The main innovation of the above scheme lies in mastering the evolution law of the magnitude and range of the superimposed stress of the abnormality during two mining operations of the triangular coal pillar, revealing the pressure change law of the coal pillar in the two mining sections and the manifestation mechanism of strong mine pressure, clarifying the area of ​​strong mine pressure in the working face roadway, and deriving the scope of strengthening support, the scope of key support and the timing, so as to provide a scientific basis for determining the correct strengthening support countermeasures.

[0135] This application addresses the stress concentration and stress rise zone that occurs during the mining of shallow, closely spaced coal seams with triangular oblique coal pillars. As the size of the overlying triangular oblique coal pillar decreases, the stress in the overlapping area between the triangular oblique coal pillar and the coal pillar in the same coal seam section becomes significant. Within the influence range of the triangular oblique coal pillar and the section coal pillar, the stress in the roadway and coal pillar increases sharply, forming a stress core zone of the triangular coal pillar, leading to significant roof subsidence and spalling in the roadway. Based on FLAC3D three-dimensional numerical simulation software, this application studies the distribution characteristics of the stress field in the coal seam working face under the influence of obliquely superimposed coal pillars. It grasps the evolution law of the magnitude and range of abnormally high superimposed stress during two mining operations with triangular coal pillars, reveals the pressure change law of the coal pillar in the two mining sections and the failure mechanism of adjacent roadways, identifies the areas in the lower coal seam working face prone to strong mine pressure, and provides the research approach, main analysis content, stress cloud diagram, and law curves for this type of three-dimensional problem, providing theoretical and technical support for the safe mining of similar working faces.

[0136] This application also provides a device for determining a mining pressure area. It should be noted that this device can be used to execute the method for determining a mining pressure area provided in this application. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0137] The following describes the apparatus for determining the mining pressure zone provided in the embodiments of this application.

[0138] Figure 28 This is a structural block diagram of a device for determining a mining pressure zone according to an embodiment of this application. Figure 28 As shown, the device includes:

[0139] The first acquisition unit 10 is used to acquire the first stress of the first coal pillar of the first coal seam working face at a first moment, wherein the first coal pillar is a coal pillar located in the first coal seam working face, the first coal seam working face is a working face with a coal seam in a coal mine, and the first moment is any coal mining moment.

[0140] The second acquisition unit 20 is used to acquire the second stress of the second coal pillar of the second coal seam working face at a second time, wherein the first coal seam working face and the second coal seam working face are separated by a predetermined distance, the area between the first coal seam working face and the second coal seam working face is a triangular area, the first time is earlier than the second time, the second coal pillar is a coal pillar located in the second coal seam working face, and the first coal pillar and the second coal pillar are obliquely intersecting.

[0141] The first determining unit 30 is used to determine the mining pressure area based on the magnitude relationship between the first stress and the second stress, wherein the difference between the first stress and the second stress is directly proportional to the magnitude of the mining pressure.

[0142] The second determining unit 40 is used to determine the degree of support for the coal mine based on the aforementioned mining pressure area, wherein the magnitude of the mining pressure in the aforementioned mining pressure area is directly proportional to the degree of support.

[0143] This embodiment obtains the stress of the working face at different times: the first time is before mining and the second time is after mining. Therefore, for a triangular oblique coal pillar, the evolution law of stress can be obtained based on its stress changes. Then, based on the stress magnitude, the areas of the working face that are prone to strong or weak mining pressure can be determined. This fills the technical gap in the existing technology for the study of mining pressure in triangular areas, thereby improving the mining efficiency of the triangular oblique coal pillar working face.

[0144] In the specific implementation process, the above scheme also includes a third acquisition unit, a first construction unit, and a processing unit. The third acquisition unit is used to acquire mining information of the working face before acquiring the first stress of the first coal pillar of the first coal seam working face at the first moment. The mining information includes one or more of the following: coal seam burial depth, mining height, rock mechanics parameters, coal pillar size, and oblique angle between two adjacent working faces at the coal mine site. The working face is the first coal seam working face or the second coal seam working face. The first construction unit is used to construct a three-dimensional model of the working face using FLAC3D software. The three-dimensional model is a virtual model of the working face. The processing unit is used to simulate coal mining operations using FLAC3D software and generate a cloud map. The colors in the cloud map correspond one-to-one with the stresses, and the depth of the colors in the cloud map is directly proportional to the magnitude of the stresses.

[0145] In this scheme, FLAC3D three-dimensional numerical simulation software is used to construct a three-dimensional model to restore the size and environment of the triangular coal pillar as much as possible, thereby simulating coal mining operations, restoring the working face of the coal mining, and improving the accuracy of subsequent stress analysis results.

[0146] In the specific implementation process, the first acquisition unit includes a first acquisition module and a second acquisition module. The first acquisition module is used to acquire the first sub-stress of the first sub-coal pillar of the first sub-coal seam working face at the first moment, wherein the first sub-coal seam working face is a part of the working face of the first coal seam working face, and the first sub-coal pillar is a coal pillar located in the working face of the first sub-coal seam working face. The first sub-stress is obtained according to the color in the cloud map. The second acquisition module is used to acquire the second sub-stress of the second sub-coal pillar of the second sub-coal seam working face at the first moment, wherein the second sub-coal seam working face is a part of the working face of the first coal seam working face, and the second sub-coal pillar is a coal pillar located in the working face of the second sub-coal seam working face. There is a coal seam with a triangular region between the first sub-coal seam working face and the second sub-coal seam working face. Before the second coal seam working face is mined, the first sub-coal pillar and the second sub-coal pillar transmit stress to the second coal seam working face. The second sub-stress is obtained according to the color in the cloud map.

[0147] In this scheme, the first coal seam working face is the working face during one mining operation. During one mining operation, the stress changes of the first sub-coal pillar and the second sub-coal pillar can be determined by the color changes in the cloud map, thereby determining the stress characteristics of the coal pillar more accurately and the evolution law of the stress of the coal pillar during the mining operation more accurately.

[0148] In the specific implementation process, the aforementioned second time moment includes a first sub-time moment and a second sub-time moment, with the first sub-time moment preceding the second sub-time moment. The aforementioned second coal seam working face includes a third sub-coal seam working face and a fourth sub-coal seam working face. Coal is mined from the third sub-coal seam working face at the first sub-time moment and from the fourth sub-coal seam working face at the second sub-time moment. The second acquisition unit includes a third acquisition module, a fourth acquisition module, and a fifth acquisition module. The third acquisition module is used to acquire the third sub-stress of the third sub-coal pillar when mining the third sub-coal seam working face at the first sub-time moment. The third sub-coal pillar is a coal pillar located in the third sub-coal seam working face. The distance between the third sub-coal seam working face and the oblique intersection point is directly proportional to the magnitude of the third sub-stress. The oblique intersection point is the first sub-coal pillar and the upper... The fourth acquisition module is used to acquire the fourth sub-stress of the fourth sub-coal pillar when mining the third sub-coal seam face at the first sub-time point. The fourth sub-coal pillar is a coal pillar located within the fourth sub-coal seam face. The distance between the fourth sub-coal seam face and the oblique intersection point is directly proportional to the magnitude of the fourth sub-stress, which is obtained based on the color in the cloud map. The fifth acquisition module is used to acquire the fifth sub-stress of the fourth sub-coal pillar when mining the fourth sub-coal seam face at the second sub-time point. The distance between the fourth sub-coal seam face and the oblique intersection point is directly proportional to the magnitude of the fifth sub-stress, which is obtained based on the color in the cloud map.

[0149] In this scheme, the second coal seam working face is the working face during the second mining period. During the second mining period, the stress changes of the third and fourth sub-coal pillars can be determined by the color changes in the cloud map, thereby determining the stress characteristics of the coal pillars more accurately and the evolution law of the stress of the coal pillars during the mining period more accurately.

[0150] To further provide a basis for roadway support, the above-mentioned device also includes a fourth acquisition unit and a second construction unit. The fourth acquisition unit is used to acquire the third stress of the fourth sub-coal seam working face before determining the mining pressure area based on the magnitude relationship between the first stress and the second stress, when mining the fourth sub-coal seam working face. The third stress is obtained according to the color in the cloud map. There are multiple third stresses, and the number of third stresses corresponds one-to-one with the distance between the fourth sub-coal seam working face and the oblique intersection point. The second construction unit is used to construct a stress curve based on the multiple third stresses. The horizontal axis of the stress curve is the length of the fourth sub-coal seam working face, and the vertical axis of the stress curve is the stress value.

[0151] In this scheme, a stress curve can be constructed after obtaining the third stress. This stress curve can clearly represent the changes and evolution of stress, providing a basis for subsequent roadway support.

[0152] In some embodiments, the above-described apparatus further includes a fifth acquisition unit, a sixth acquisition unit, and a third determination unit. The fifth acquisition unit is used to acquire the first position of the first coal pillar before determining the mining pressure area based on the magnitude relationship between the first stress and the second stress. The sixth acquisition unit is used to acquire the second position of the second coal pillar. The third determination unit is used to determine the stress concentration area based on the first position and the second position, wherein stress concentration characterizes the stress superposition of at least two coal pillars, and the distance between the first position and the second position is proportional to the degree of stress concentration.

[0153] In this scheme, the stress in the coal pillar may be superimposed during the mining of the working face, which will cause the stress to increase. Therefore, the stress concentration area can be identified to provide a theoretical basis for subsequent roadway support.

[0154] In some embodiments, the first determining unit includes a first determining module and a second determining module. The first determining module is used to determine the current area as a first mining pressure area when the first stress is less than the second stress, the difference between the first stress and the second stress is greater than the first difference, and the difference between the first stress and the second stress is less than the second difference, wherein the first difference is less than the second difference. The second determining module is used to determine the current area as a second mining pressure area when the first stress is less than the second stress, and the difference between the first stress and the second stress is greater than or equal to the second difference, wherein the stress in the first mining pressure area is less than the stress in the second mining pressure area.

[0155] In this scheme, after determining the magnitude and evolution of stress under two mining conditions, the region of mine pressure in the roadway of the working face can be identified. The mine pressure in different regions is different, and the scope and timing of support can then be determined based on the magnitude of the mine pressure in the region.

[0156] The aforementioned device for determining the mining pressure area includes a processor and a memory. The first acquisition unit, second acquisition unit, first determination unit, and second determination unit are all stored as program units in the memory. The processor executes these program units stored in the memory to achieve their respective functions. All of the above modules are located in the same processor; alternatively, the modules may be located in different processors in any combination.

[0157] The processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured, and adjusting kernel parameters can address the problem in existing technologies where the mining efficiency of triangular oblique coal pillar working faces is poor due to the inability to determine the mine pressure.

[0158] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0159] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the method for determining the mining pressure area.

[0160] This invention provides a processor for running a program, wherein the program executes the method for determining the mining pressure area.

[0161] This invention provides a device including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements at least the method steps for determining a mining pressure area. The device described herein can be a server, PC, PAD, mobile phone, etc.

[0162] A computer program product includes a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method for determining the mining pressure area described in various embodiments of this application.

[0163] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0164] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0165] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0166] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0167] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0168] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0169] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0170] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0171] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0172] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0173] 1) The method for determining the mining pressure zone in this application obtains the stress of the working face at different times. The first time is before the working face is mined, and the second time is after the working face is mined. Therefore, for a triangular oblique coal pillar, the evolution law of stress is obtained according to the change of its stress. Then, the area of ​​strong mining pressure or weak mining pressure in the working face is determined according to the magnitude of stress. This fills the technical gap in the existing technology for the study of mining pressure in triangular areas, thereby improving the mining efficiency of the working face of the triangular oblique coal pillar.

[0174] 2) The device for determining the mining pressure area in this application acquires the stress of the working face at different times. The first time is before the working face is mined, and the second time is after the working face is mined. Therefore, for a triangular oblique coal pillar, the evolution law of stress can be obtained based on the change of its stress. Then, the area of ​​the working face that is prone to strong mining pressure or weak mining pressure can be determined based on the magnitude of stress. This fills the technical gap in the existing technology for the study of mining pressure in triangular areas, thereby improving the mining efficiency of the working face of the triangular oblique coal pillar.

[0175] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for determining a mining pressure zone, characterized in that, include: The first stress of the first coal pillar of the first coal seam working face at the first moment is obtained, wherein the first coal pillar is a coal pillar located in the first coal seam working face, the first coal seam working face is a working face with a coal seam in a coal mine, and the first moment is any coal mining moment. The second stress of the second coal pillar of the second coal seam working face at the second time is obtained, wherein the first coal seam working face and the second coal seam working face are separated by a predetermined distance, the area between the first coal seam working face and the second coal seam working face is a triangular area, the first time is earlier than the second time, the second coal pillar is a coal pillar located in the second coal seam working face, and the first coal pillar and the second coal pillar are obliquely intersecting. Based on the relationship between the magnitudes of the first stress and the second stress, the mining pressure zone is determined, wherein the difference between the first stress and the second stress is directly proportional to the magnitude of the mining pressure. The degree of support for the coal mine is determined based on the mining pressure area, wherein the magnitude of the mining pressure in the mining pressure area is directly proportional to the degree of support.

2. The method according to claim 1, characterized in that, Before obtaining the first stress of the first coal pillar at the first moment of the first coal seam working face, the method further includes: Obtain mining information of the working face, wherein the mining information includes one or more of the following: coal seam burial depth, mining height, rock mechanics parameters, coal pillar size, and oblique angle between two adjacent working faces at the coal mine site; the working face is the first coal seam working face or the second coal seam working face. A three-dimensional model of the working surface is constructed using FLAC3D software, wherein the three-dimensional model is a virtual model of the working surface; The coal mining operation was simulated using FLAC3D software, and a cloud map was generated. In the cloud map, the colors corresponded one-to-one with the stress, and the intensity of the colors in the cloud map was directly proportional to the magnitude of the stress.

3. The method according to claim 2, characterized in that, Obtaining the first stress of the first coal pillar at the first moment of the first coal seam working face includes: The first sub-stress of the first sub-coal pillar in the first sub-coal seam working face at the first moment is obtained, wherein the first sub-coal seam working face is a part of the first coal seam working face, the first sub-coal pillar is a coal pillar located in the first sub-coal seam working face, and the first sub-stress is obtained according to the color in the cloud map. The second sub-stress of the second sub-coal pillar in the second sub-coal seam working face at the first moment is obtained. The second sub-coal seam working face is a part of the first coal seam working face, and the second sub-coal pillar is a coal pillar located in the second sub-coal seam working face. There is a coal seam with a triangular region between the first sub-coal seam working face and the second sub-coal seam working face. Before the second coal seam working face is mined, the first sub-coal pillar and the second sub-coal pillar transmit stress to the second coal seam working face. The second sub-stress is obtained according to the color in the cloud map.

4. The method according to claim 3, characterized in that, The second time point includes a first sub-time point and a second sub-time point, where the first sub-time point is earlier than the second sub-time point. The second coal seam working face includes a third sub-coal seam working face and a fourth sub-coal seam working face. Coal is mined at the third sub-coal seam working face at the first sub-time point and at the fourth sub-coal seam working face at the second sub-time point. The second stress of the second coal pillar of the second coal seam working face at the second time point is obtained, including: When mining coal at the third sub-coal seam working face at the first sub-moment, the third sub-stress of the third sub-coal pillar is obtained. The third sub-coal pillar is a coal pillar located in the third sub-coal seam working face. The distance between the third sub-coal seam working face and the oblique intersection point is directly proportional to the magnitude of the third sub-stress. The oblique intersection point is the intersection point between the first sub-coal pillar and the third sub-coal pillar. The third sub-stress is obtained based on the color in the cloud map. When mining coal at the third sub-coal seam working face at the first sub-moment, the fourth sub-stress of the fourth sub-coal pillar is obtained. The fourth sub-coal pillar is a coal pillar located in the fourth sub-coal seam working face. The distance between the fourth sub-coal seam working face and the oblique intersection point is directly proportional to the magnitude of the fourth sub-stress. The fourth sub-stress is obtained based on the color in the cloud map. When mining coal at the fourth sub-coal seam working face at the second sub-time, the fifth sub-stress of the fourth sub-coal pillar is obtained, wherein the distance between the fourth sub-coal seam working face and the oblique intersection point is directly proportional to the magnitude of the fifth sub-stress, and the fifth sub-stress is obtained based on the color in the cloud map.

5. The method according to claim 4, characterized in that, Before determining the mining pressure zone based on the magnitude relationship between the first stress and the second stress, the method further includes: When mining the fourth sub-coal seam working face, the third stress of the fourth sub-coal seam working face is obtained. The third stress is obtained according to the color in the cloud map. There are multiple third stresses, and the number of third stresses corresponds one-to-one with the distance between the fourth sub-coal seam working face and the oblique intersection point. Based on the multiple third stresses, a stress curve is constructed, wherein the horizontal axis of the stress curve is the length of the fourth sub-coal seam working face, and the vertical axis of the stress curve is the stress value.

6. The method according to claim 1, characterized in that, Before determining the mining pressure zone based on the magnitude relationship between the first stress and the second stress, the method further includes: Obtain the first position of the first coal pillar; Obtain the second position of the second coal pillar; Based on the first position and the second position, a stress concentration region is determined, wherein stress concentration characterizes the stress superposition of at least two coal pillars, and the distance between the first position and the second position is directly proportional to the degree of stress concentration.

7. The method according to claim 1, characterized in that, Based on the magnitude relationship between the first stress and the second stress, the mining pressure zone is determined, including: When the first stress is less than the second stress, the difference between the first stress and the second stress is greater than the first difference, and the difference between the first stress and the second stress is less than the second difference, the current area is determined to be the first mining pressure area, wherein the first difference is less than the second difference; When the first stress is less than the second stress, and the difference between the first stress and the second stress is greater than or equal to the second difference, the current area is determined to be the second mining pressure area, wherein the stress in the first mining pressure area is less than the stress in the second mining pressure area.

8. A device for determining a mining pressure zone, characterized in that, include: The first acquisition unit is used to acquire the first stress of the first coal pillar of the first coal seam working face at the first moment, wherein the first coal pillar is a coal pillar located in the first coal seam working face, the first coal seam working face is a working face with a coal seam in a coal mine, and the first moment is any coal mining moment. The second acquisition unit is used to acquire the second stress of the second coal pillar of the second coal seam working face at a second time, wherein the first coal seam working face and the second coal seam working face are separated by a predetermined distance, the area between the first coal seam working face and the second coal seam working face is a triangular area, the first time is earlier than the second time, the second coal pillar is a coal pillar located in the second coal seam working face, and the first coal pillar and the second coal pillar are obliquely intersecting. The first determining unit is used to determine the mining pressure area based on the magnitude relationship between the first stress and the second stress, wherein the difference between the first stress and the second stress is directly proportional to the magnitude of the mining pressure. The second determining unit is used to determine the degree of support for the coal mine based on the mining pressure area, wherein the magnitude of the mining pressure in the mining pressure area is directly proportional to the degree of support.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method for determining the mining pressure area as described in any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the method for determining the mining pressure zone as described in any one of claims 1 to 7.

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