A method for determining the critical thickness of a coal pillar for isolating a fire zone in a coal mine underground

Abstract

The application provides a coal pillar critical thickness determination method for isolating a fire area in a coal mine underground, which is based on the edge temperature of the isolated fire area, the critical spontaneous combustion temperature, the heat conductivity coefficient and the equivalent thermal diffusion coefficient of the isolated pillar coal body to determine the thermal isolation thickness of the effective isolated fire area; based on the fracture zone width of the edge of the isolated fire area, the permeability and the critical oxygen seepage velocity of the isolated pillar coal body to determine the fracture sealing thickness of the effective isolated fire area; based on the original rock stress and the stress concentration coefficient after mining disturbance, the uniaxial compressive strength and the residual strength of the isolated pillar coal body to determine the mining disturbance resistance thickness of the effective isolated fire area; the maximum value among the thermal isolation thickness, the fracture sealing thickness and the mining disturbance resistance thickness is taken as the critical thickness of the isolated pillar; through the above technical scheme, the reasonable coal pillar thickness is determined, the fire area can be effectively isolated, and the fire area isolation failure is avoided.

Description

Technical Field

[0001] This application relates to the field of coal mine safety technology, and in particular to a method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines. Background Technology

[0002] Mine fires are among the most insidious and destructive disasters in the field of coal mine safety. Fires caused by spontaneous combustion of coal in goaf areas can generate high temperatures of over 300°C, toxic and harmful gases, and complex thermo-mechanical-fracture coupling effects. This not only seriously threatens the safety of underground personnel but may also lead to secondary disasters such as gas explosions or coal dust explosions.

[0003] For mining activities in areas adjacent to the fire zone, when mining is carried out on both sides of the fire zone at the same level in the same coal seam, in the lower section of the fire zone with a coal seam dip angle of less than 35°, and in the adjacent coal seam below the fire zone, it is necessary to leave a sufficiently wide (thick) isolation coal (rock) pillar to ensure that the fire zone can be effectively isolated and that firefighting work is not affected.

[0004] However, current engineering practices mostly rely on empirical values ​​(such as 30m, 50m) or calculations based on a single factor, lacking a systematic quantitative design method that simultaneously considers heat conduction blocking, fissure seepage sealing, resistance to mining disturbances, and ensuring space for firefighting operations. This results in either insufficient thickness of the isolation pillars leading to fire reignition or gas leaks, or excessive thickness of the coal pillars resulting in a large amount of drilling work, easy deviation of the drilling trajectory, difficulty in efficiently carrying out firefighting work, and waste of coal resources. Summary of the Invention

[0005] This application provides a method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines. This method solves the problem of low accuracy in the thickness of coal pillars in the prior art, and achieves reasonable setting of coal pillar thickness, which can effectively isolate fire zones and avoid fire zone isolation failure.

[0006] To achieve the above objectives, this application provides a method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines, the method comprising: Based on the edge temperature of the isolated fire zone, the critical auto-ignition temperature, thermal conductivity, and equivalent thermal diffusivity of the coal body in the isolation column, the thermal isolation thickness of the effective isolated fire zone is determined. Based on the width of the fracture zone at the edge of the isolated fire zone, the permeability of the coal body in the isolation column, and the critical oxygen seepage velocity, the fracture sealing thickness of the effective isolated fire zone is determined. Based on the original rock stress and the stress concentration factor after mining disturbance, the uniaxial compressive strength and residual strength of the coal body of the isolation column, the effective mining disturbance resistance thickness of the fire isolation zone is determined. The maximum value among the thermal isolation thickness, the fracture sealing thickness, and the mining disturbance resistance thickness is taken as the critical thickness of the isolation column.

[0007] In one possible implementation, the method further includes: When the fire zone is effectively isolated from the adjacent coal seam below, the thickness of the gravity collapse effect is obtained; the thickness of the gravity collapse effect is determined based on the coal seam spacing. The maximum value among the thermal isolation thickness, the fissure sealing thickness, the mining disturbance resistance thickness, and the gravity collapse influence thickness is taken as the critical thickness of the isolation column.

[0008] In one possible implementation, the method further includes: When the coal seam dip angle is greater than or equal to a preset angle threshold, the critical thickness of the isolation column is increased by a preset ratio to resist the sliding force.

[0009] In one possible implementation, determining the effective thermal isolation thickness of the fire isolation zone based on the edge temperature of the fire isolation zone, the critical auto-ignition temperature of the coal in the isolation column, its thermal conductivity, and its equivalent thermal diffusivity includes: Set a safe isolation time; Based on the aforementioned safety isolation time, edge temperature, critical auto-ignition temperature, thermal conductivity, and equivalent thermal diffusivity, combined with a semi-infinite one-dimensional thermal conduction model, the thermal isolation thickness is determined. The thermal insulation thickness determined above is expressed by the formula: ; in, For thermal insulation thickness, The equivalent thermal diffusivity, For safe isolation time, It is the inverse function of the error function. For edge temperature, The critical auto-ignition temperature. This represents the original temperature of the rock strata.

[0010] In one possible implementation, determining the effective fissure sealing thickness of the fire isolation zone based on the width of the fracture zone at the edge of the fire isolation zone, the permeability of the coal body in the isolation column, and the critical oxygen seepage velocity includes: Based on the permeability and critical oxygen flow velocity, and in conjunction with Darcy's law, the target fracture sealing thickness is determined. The sum of the target fissure sealing thickness and the fissure band width is taken as the fissure sealing thickness.

[0011] In one possible implementation, the process of determining the target fracture plugging thickness described above is expressed by the following formula: ;in, The target fracture sealing thickness, To isolate the fire zone from the external air pressure difference, For gas dynamic viscosity, The critical oxygen percolation velocity, For penetration rate; The above summation process can be expressed by the following formula: ;in, For the thickness of the crack sealing, The target fracture sealing thickness, This represents the width of the fracture zone.

[0012] In one possible implementation, determining the effective fire-isolation zone's resistance thickness to mining disturbance based on the original rock stress and the stress concentration factor after mining disturbance, the uniaxial compressive strength and residual strength of the isolation pillar coal body, includes: The depth of the mining disturbance plastic zone is determined based on the original rock stress, stress concentration factor, uniaxial compressive strength and residual strength; The thickness of the mining disturbance resistance is determined based on the depth of the plastic zone of the mining disturbance and the disturbance safety factor.

[0013] In one possible implementation, the process of determining the depth of the mining disturbance plastic zone described above is expressed by the following formula: ;in, To the depth of the disturbed plastic zone, To determine the thickness or height of the tunnel, The stress concentration factor is... For the original rock stress, Uniaxial compressive strength; The process of determining the resistance thickness to mining disturbance described above can be expressed by the following formula: ;in, To resist the thickness of the material during mining disturbances, To the depth of the disturbed plastic zone, This is the disturbance safety factor.

[0014] In one possible implementation, the method further includes: The isolation columns are arranged according to the critical thickness and preset spacing of the isolation columns; Real-time acquisition of the status parameters of the isolation column; the status parameters include internal temperature, Concentration, pressure difference between the two sides, and surface displacement; If any of the state parameters exceeds the limit, adjust the critical thickness of the isolation column.

[0015] In one possible implementation, adjusting the critical thickness of the isolation column when any of the state parameters exceeds the limit includes: If the internal temperature is greater than a first preset threshold, the critical thickness of the isolation column will be increased by a first preset percentage. In the If the concentration is greater than the second preset threshold, the critical thickness of the isolation column will be increased by the second preset ratio; If the pressure difference between the two sides is greater than a third preset threshold, the critical thickness of the isolation column will be increased by a third preset ratio. If the surface displacement is greater than a fourth preset threshold, the critical thickness of the isolation column will be increased by a fourth preset ratio.

[0016] The technical solutions provided in this application embodiment have at least the following technical effects or advantages: The critical thickness of the isolation pillar is determined by considering the thermal isolation thickness, the fracture sealing thickness, and the resistance thickness to mining disturbance. This serves as a reasonable coal pillar thickness, improving the accuracy of isolation pillar thickness setting. Based on the determined critical thickness of the isolation pillar, the fire zone can be effectively isolated, preventing fire zone isolation failure and ensuring fire extinguishing safety. Furthermore, the improved accuracy of the critical thickness of the isolation pillar also improves the accuracy of the drilling trajectory, reducing the need for extensive construction, thus reducing drilling volume and minimizing coal resource waste. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating a method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines, provided as an embodiment of this application; Figure 2 A flowchart illustrating another method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines, provided in an embodiment of this application; Figure 3 A flowchart illustrating another method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines, provided in an embodiment of this application; Figure 4 A flowchart illustrating another method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines, provided as an embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0021] Figure 1 This application provides a flowchart of a method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines. As shown in Title 1, the method may include the following steps.

[0022] S101. Based on the edge temperature of the isolated fire zone, the critical auto-ignition temperature, thermal conductivity, and equivalent thermal diffusivity of the coal in the isolation column, determine the thermal isolation thickness of the effective isolated fire zone.

[0023] For example, the edge temperature of the isolated fire zone can be obtained through borehole thermography or infrared detection; the unit of edge temperature is °C. The critical auto-ignition temperature can be obtained through adiabatic oxidation experiments, and is generally between 60 and 80 °C. The unit of thermal conductivity is... The unit of the equivalent thermal diffusivity is . .

[0024] S102. Based on the width of the fracture zone at the edge of the isolated fire zone, the permeability of the coal body in the isolation column, and the critical oxygen seepage velocity, determine the fracture sealing thickness of the effective isolated fire zone.

[0025] For example, the width of the fracture zone can be determined by borehole imaging, tracer gas testing, or fracture statistics, and the unit is meters (m). The unit of permeability is mD, and the critical oxygen permeation velocity is generally taken as... .

[0026] S103. Based on the original rock stress and the stress concentration factor after mining disturbance, the uniaxial compressive strength and residual strength of the coal body of the isolation column are used to determine the effective mining disturbance resistance thickness of the fire isolation zone.

[0027] For example, the original rock stress can be determined using numerical simulation (FLAC3D, RFPA) or in-situ stress testing, and the unit is MPa.

[0028] S104. The maximum value among the thermal isolation thickness, the fracture sealing thickness, and the mining disturbance resistance thickness shall be taken as the critical thickness of the isolation column.

[0029] For example, the process of selecting the maximum value described above can be represented as: ;in, This represents the critical thickness of the isolation column. For thermal insulation thickness, For the thickness of the crack sealing, Thickness to resist mining disturbances.

[0030] It should be noted that the isolation pillar can be either coal seam or rock seam, and the critical thickness of the isolation pillar can be either the critical thickness for isolating a coal pillar or the critical thickness for isolating a rock pillar. Furthermore, when the isolation pillar is coal seam, relevant parameters of the coal seam can be collected; when the isolation pillar is rock seam, relevant parameters of the rock seam can be collected.

[0031] The critical thickness of the isolation pillar is determined by considering the thermal isolation thickness, the fracture sealing thickness, and the resistance thickness to mining disturbance. This serves as a reasonable coal pillar thickness, improving the accuracy of isolation pillar thickness setting. Based on the determined critical thickness of the isolation pillar, the fire zone can be effectively isolated, preventing fire zone isolation failure and ensuring fire extinguishing safety. Furthermore, the improved accuracy of the critical thickness of the isolation pillar also improves the accuracy of the drilling trajectory, reducing the need for extensive construction, thus reducing drilling volume and minimizing coal resource waste.

[0032] Figure 2 A flowchart illustrating another method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines, provided as an embodiment of this application. Figure 2 As shown, the method may also include the following steps.

[0033] S105. When the fire zone is effectively isolated and located in the adjacent coal seam below, obtain the thickness of the gravity collapse effect; the thickness of the gravity collapse effect is determined based on the coal seam spacing.

[0034] For example, the adjacent coal seam below specifically refers to the adjacent coal seam located (below) the floor of the mined coal seam. The thickness of the gravity collapse effect can be expressed as: ;in, The thickness is affected by gravity collapse. This represents the coal seam spacing, in meters (m).

[0035] S106. The maximum value among the thermal isolation thickness, the fissure sealing thickness, the mining disturbance resistance thickness, and the gravity collapse influence thickness shall be taken as the critical thickness of the isolation column.

[0036] For example, the above process can be represented as: ;in, The thickness is affected by gravity collapse.

[0037] Figure 3 A flowchart illustrating another method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines, provided as an embodiment of this application. Figure 3 As shown, the method may also include the following steps.

[0038] S107. When the dip angle of the coal seam is greater than or equal to the preset angle threshold, the critical thickness of the isolation column is increased by a preset ratio to resist the sliding force.

[0039] For example, the preset angle threshold can be between 20° and 30°, such as 20°, 25° or 30°, and the preset percentage can be 8%-15%, such as 8%, 10% or 15%, etc., which are not limited here.

[0040] In one possible implementation, S101 includes: setting a safety isolation time; determining the thermal isolation thickness based on the safety isolation time, edge temperature, critical auto-ignition temperature, thermal conductivity, and equivalent thermal diffusivity, combined with a semi-infinite one-dimensional heat conduction model; the determination of the thermal isolation thickness is expressed by the formula: ;in, For thermal insulation thickness, The equivalent thermal diffusivity is obtained through field borehole thermal response tests, and is generally taken as... , For safe isolation time, It is the inverse function of the error function. For edge temperature, The critical auto-ignition temperature. This represents the original temperature of the rock strata.

[0041] For example, a safe isolation time is set, meaning that the fire zone should not ignite the isolation column within a preset fire extinguishing cycle (e.g., 180 days). The unit of safe isolation time is days.

[0042] In one possible implementation, S102 includes: determining the target fracture sealing thickness based on the permeability and critical oxygen permeation velocity, combined with Darcy's law of permeability; and using the sum of the target fracture sealing thickness and the fracture zone width as the fracture sealing thickness.

[0043] In one possible implementation, the process of determining the target fracture plugging thickness described above is expressed by the following formula: ;in, The target fracture sealing thickness, To isolate the fire zone from the external air pressure difference, the unit is Pa. This refers to the gas dynamic viscosity, in units of... , The critical oxygen percolation velocity, The above summation process is expressed by the formula: (The formula is missing here, but it doesn't need to be translated.) ;in, For the thickness of the crack sealing, The target fracture sealing thickness, This represents the width of the fracture zone.

[0044] In one possible implementation, S103 includes: determining the depth of the mining disturbance plastic zone based on the original rock stress, stress concentration factor, uniaxial compressive strength and residual strength; and determining the mining disturbance resistance thickness according to the depth of the mining disturbance plastic zone and the disturbance safety factor.

[0045] In one possible implementation, the process of determining the depth of the mining disturbance plastic zone described above is expressed by the following formula: ;in, To the depth of the disturbed plastic zone, This refers to the thickness of the excavated material or the height of the tunnel, expressed in meters (m). The stress concentration factor is... For the original rock stress, The uniaxial compressive strength; the process of determining the thickness resisting mining disturbance described above is expressed by the formula: ;in, To resist the thickness of the material during mining disturbances, To the depth of the disturbed plastic zone, The disturbance safety factor is set to 1.2 to 1.5.

[0046] Figure 4 A flowchart illustrating another method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines, provided as an embodiment of this application. Figure 4 As shown, the method may also include the following steps.

[0047] S108. Install the isolation columns according to the critical thickness and preset spacing of the isolation columns.

[0048] For example, verification boreholes or isolation columns can be placed at preset locations with a preset spacing of less than or equal to 50m.

[0049] S109. Real-time acquisition of the status parameters of the isolation column.

[0050] Among them, the state parameter is the internal temperature, Concentration, pressure difference between the two sides, and surface displacement.

[0051] S110. If any parameter in this state parameter exceeds the standard, adjust the critical thickness of the isolation column.

[0052] In some embodiments, S110 may include: increasing the critical thickness of the isolation column by a first preset ratio when the internal temperature is greater than a first preset threshold; If the concentration is greater than the second preset threshold, the critical thickness of the isolation column is increased by the second preset ratio; if the pressure difference between the two sides is greater than the third preset threshold, the critical thickness of the isolation column is increased by the third preset ratio; if the surface displacement is greater than the fourth preset threshold, the critical thickness of the isolation column is increased by the fourth preset ratio.

[0053] For example, the first preset threshold can be 35-45℃, such as 35℃, 40℃, or 45℃; the second preset threshold can be 2-5%, such as 2%, 3%, or 5%; the third preset threshold can be 15-25Pa, such as 15Pa, 20Pa, or 25Pa; the fourth preset threshold can be 45-55mm, such as 45mm, 50mm, or 55mm; the first preset ratio can be 8-13%, such as 8%, 10%, or 13%; the second preset ratio can be 12-18%, such as 12%, 15%, or 18%; the third preset ratio can be 3-8%, such as 3%, 5%, or 8%, etc., and no limitation is made here.

[0054] For example, the above process may include the following construction verification and dynamic adjustment steps: (1) Arrange verification boreholes at the designed location of the isolation column, with a spacing of less than or equal to 50m. (2) After the isolation column construction is completed and during the mining process, continuously monitor the following indicators: internal temperature of the isolation column (≤ 40℃); internal temperature of the isolation column. Concentration (≤ 3%); Pressure difference across the isolation column ( ); Surface displacement of the isolation column (≤ 50mm). (3) If any of the above indicators exceed the standard, the isolation column shall be thickened according to the preset rules.

[0055] For example, when the temperature inside the isolation column is greater than 40°C, the temperature inside the isolation column... If the concentration is greater than 3%, the pressure difference between the two sides of the isolation column is greater than 20 Pa, or the displacement of the isolation column surface is greater than 50 mm, it is determined that any of the indicators exceeds the standard, and the isolation column can be thickened according to the preset rules.

[0056] For example, the preset rule could be: when the internal temperature of the isolation column increases by 10°C, the thickness of the isolation column increases by 10%; when... For every 1% increase in concentration, the thickness of the isolation column increases by 15%; for every 10 Pa increase in the pressure difference across the isolation column, the thickness of the isolation column increases by 5%.

[0057] The existing "Detailed Rules for Fire Prevention and Extinguishing in Coal Mines" stipulates that when mining on both sides of a fire zone at the same level in the same coal seam, in the lower section of a fire zone with a coal seam dip angle of less than 35°, and in adjacent coal seams below the fire zone, a sufficiently wide (thick) isolation coal (rock) pillar must be left to ensure effective isolation of the fire zone without affecting firefighting efforts. This regulation aims to "effectively isolate the fire zone" and "not affect firefighting efforts." Therefore, the technical solution provided in this application can transform the aforementioned requirement of "sufficient width (thickness)" into a quantifiable, operable, and verifiable method for determining the thickness of the isolation coal (rock) pillar, simultaneously satisfying both the requirements of "effectively isolating the fire zone" and "not affecting firefighting efforts," thus achieving accurate setting of the isolation coal (rock) pillar thickness.

[0058] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0059] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A method for determining the critical thickness of a coal pillar for isolating fire zones in underground coal mines, characterized in that, The method includes: Based on the edge temperature of the isolated fire zone, the critical auto-ignition temperature, thermal conductivity, and equivalent thermal diffusivity of the coal body in the isolation column, the thermal isolation thickness of the effective isolated fire zone is determined. Based on the width of the fracture zone at the edge of the isolated fire zone, the permeability of the coal body in the isolation column, and the critical oxygen seepage velocity, the fracture sealing thickness of the effective isolated fire zone is determined. Based on the original rock stress and the stress concentration factor after mining disturbance, the uniaxial compressive strength and residual strength of the coal body of the isolation column, the effective mining disturbance resistance thickness of the fire isolation zone is determined. The maximum value among the thermal isolation thickness, the fracture sealing thickness, and the mining disturbance resistance thickness is taken as the critical thickness of the isolation column.

2. The method according to claim 1, characterized in that, The method further includes: When the fire zone is effectively isolated from the adjacent coal seam below, the thickness of the gravity collapse effect is obtained; the thickness of the gravity collapse effect is determined based on the coal seam spacing. The maximum value among the thermal isolation thickness, the fissure sealing thickness, the mining disturbance resistance thickness, and the gravity collapse influence thickness is taken as the critical thickness of the isolation column.

3. The method according to claim 1 or 2, characterized in that, The method further includes: When the coal seam dip angle is greater than or equal to a preset angle threshold, the critical thickness of the isolation column is increased by a preset ratio to resist the sliding force.

4. The method according to claim 1, characterized in that, The determination of the effective thermal isolation thickness of the fire isolation zone based on the edge temperature of the fire isolation zone, the critical auto-ignition temperature, thermal conductivity, and equivalent thermal diffusivity of the coal in the isolation column includes: Set a safe isolation time; Based on the aforementioned safety isolation time, edge temperature, critical auto-ignition temperature, thermal conductivity, and equivalent thermal diffusivity, combined with a semi-infinite one-dimensional thermal conduction model, the thermal isolation thickness is determined. The thermal insulation thickness determined above is expressed by the formula: ; in, For thermal insulation thickness, The equivalent thermal diffusivity, For safe isolation time, It is the inverse function of the error function. For edge temperature, The critical auto-ignition temperature. This represents the original temperature of the rock strata.

5. The method according to claim 1, characterized in that, The determination of the effective fissure sealing thickness for isolating the fire zone is based on the width of the fracture zone at the edge of the isolated fire zone, the permeability of the coal body in the isolation column, and the critical oxygen seepage velocity. This includes: Based on the permeability and critical oxygen flow velocity, and in conjunction with Darcy's law, the target fracture sealing thickness is determined. The sum of the target fissure sealing thickness and the fissure band width is taken as the fissure sealing thickness.

6. The method according to claim 5, characterized in that, The process of determining the target fracture sealing thickness described above can be expressed by the following formula: ;in, The target fracture sealing thickness, To isolate the fire zone from the external air pressure difference, For gas dynamic viscosity, The critical oxygen percolation velocity, For penetration rate; The above summation process can be expressed by the following formula: ;in, For the thickness of the crack sealing, The target fracture sealing thickness, This represents the width of the fracture zone.

7. The method according to claim 1, characterized in that, The determination of the effective fire-isolation zone's resistance thickness to mining disturbance, based on the original rock stress and the stress concentration factor after mining disturbance, the uniaxial compressive strength and residual strength of the coal body in the isolation pillar, includes: The depth of the mining disturbance plastic zone is determined based on the original rock stress, stress concentration factor, uniaxial compressive strength and residual strength; The thickness of the mining disturbance resistance is determined based on the depth of the plastic zone of the mining disturbance and the disturbance safety factor.

8. The method according to claim 7, characterized in that, The process of determining the depth of the disturbed plastic zone during mining is expressed by the following formula: ;in, To the depth of the disturbed plastic zone, To determine the thickness or height of the tunnel, The stress concentration factor is... For the original rock stress, Uniaxial compressive strength; The process of determining the resistance thickness to mining disturbance described above can be expressed by the following formula: ;in, To resist the thickness of the material during mining disturbances, To the depth of the disturbed plastic zone, This is the disturbance safety factor.

9. The method according to any one of claims 1 to 8, characterized in that, The method further includes: The isolation columns are arranged according to the critical thickness and preset spacing of the isolation columns; Real-time acquisition of the status parameters of the isolation column; the status parameters include internal temperature, Concentration, pressure difference between the two sides, and surface displacement; If any of the state parameters exceeds the limit, adjust the critical thickness of the isolation column.

10. The method according to claim 9, characterized in that, When any of the state parameters exceeds the limit, adjusting the critical thickness of the isolation column includes: If the internal temperature is greater than a first preset threshold, the critical thickness of the isolation column will be increased by a first preset percentage. In the If the concentration is greater than the second preset threshold, the critical thickness of the isolation column will be increased by the second preset ratio; If the pressure difference between the two sides is greater than a third preset threshold, the critical thickness of the isolation column will be increased by a third preset ratio. If the surface displacement is greater than a fourth preset threshold, the critical thickness of the isolation column will be increased by a fourth preset ratio.

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