Method and device for determining back pressure platform for preventing and controlling open pit coal fire zone

Abstract

The present invention provides a method and device for determining a backpressure platform for preventing and controlling open-pit coal fires, which relates to the technical field of open-pit coal fire prevention and control. First, based on Coulomb's earth pressure theory, the geometric parameters of the two-dimensional cross-section of the composite slope of the spoil dump, and the physical and mechanical parameters of the discarded soil, the soil pressure at the soil-rock contact surface is calculated. Then, with the purpose of weakening the shear effect of the composite slope of the spoil dump on the toe area, the amount of earth required for the backpressure platform located at the toe of the composite slope of the spoil dump is calculated when the three-dimensional space extension dimension is 1 meter. Finally, the geometric morphological conditions of the backpressure platform at the toe are set as a parallelogram and the platform slope angle is the slope angle of the spoil dump slope. The geometric parameters of the backpressure platform at the toe are calculated based on the amount of earth. The implementation cost of this method is low. By weakening the shear effect of the spoil dump slope on the toe, the displacement of the soil and rock layer at the toe of the slope is suppressed, thereby reducing the development of cracks and lowering air permeability, thereby effectively curbing the combustion and spread of the coal seam.

Description

Technical Field

[0001] The present invention relates to the technical field of prevention and control of open-pit coal fire zones, and in particular to a method and device for determining a back pressure platform for preventing and control of open-pit coal fire zones. Background Art

[0002] A coal fire is the uncontrolled combustion or smoldering of surface or underground coal seams. As the fire spreads and expands, the surrounding rock layers, exposed to prolonged high temperatures, undergo thermal metamorphism, transforming into burnt rock, ultimately forming a coal fire zone. Coal fire zones are particularly common in the arid northwest region. Due to the high temperatures and dryness of summer, outcropping and shallow coal seams are highly susceptible to spontaneous combustion. Once a coal fire zone forms, it often interacts with factors such as slope stability and groundwater, potentially triggering a series of geological hazards and threatening mine safety. During open-pit mining, waste soil is piled along the non-working sides of the stope. When the pile height exceeds the ground surface, a reverse composite slope forms. This type of slope often exerts strong shear forces on the toe area (i.e., the top of the mining slope), causing the overburden above the coal seam to fracture and create numerous fissures. Combined with high temperatures, this can induce a coal fire zone in this location, known as an induced coal fire zone on the spoil dump slope. This type of coal fire area is close to the slope of the spoil dump. Its spread and expansion will weaken the stability of the slope of the spoil dump and increase the risk of landslide. Therefore, it is necessary to carry out timely and effective management of this type of coal fire area to ensure the safety of open-pit mine production.

[0003] In terms of coal fire control measures, common methods in the prior art include: water and soil filling, excavation, liquid carbon dioxide fire extinguishing, etc. Although the above methods are widely used, the implementation costs are relatively high. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for determining a back pressure platform for preventing and controlling open-pit coal fire zones, so as to alleviate the technical problem of high implementation cost in the existing open-pit coal fire zone control methods.

[0005] In the first aspect, the present invention provides a method for determining a back pressure platform for preventing and controlling coal fires in open-pit mines, comprising: obtaining geometric parameters of a two-dimensional cross-section of a composite slope of a spoil dump and physical and mechanical parameters of the discarded soil; wherein the geometric parameters include: the angle between the soil-rock contact surface and the vertical line, the slope angle of the spoil dump slope and the height of the retaining wall; the physical and mechanical parameters include: soil weight, soil internal friction angle, soil-rock contact surface friction angle and soil cohesion; calculating the soil-rock contact surface soil pressure based on Coulomb's earth pressure theory, geometric parameters and physical and mechanical parameters; and calculating the soil-rock contact surface soil pressure based on the soil-rock contact surface soil pressure. The soil pressure on the contact surface, the friction angle of the soil-rock contact surface, the angle between the soil-rock contact surface and the vertical line, and the weight of the soil are used to calculate the amount of soil required for the slope foot counter-pressure platform when its three-dimensional space extension size is 1 meter. The slope foot counter-pressure platform is used to weaken the shear effect of the composite slope of the spoil dump on the slope foot area. The two-dimensional cross-section is a parallelogram, and the platform slope angle is the slope angle of the spoil dump slope. Based on the soil volume, the slope angle of the spoil dump slope, and the angle between the soil-rock contact surface and the vertical line, the geometric parameters of the slope foot counter-pressure platform are calculated.

[0006] In an optional embodiment, the soil pressure at the soil-rock contact surface is calculated based on Coulomb's earth pressure theory, geometric parameters and physical and mechanical parameters, including: using the equivalent internal friction angle method to process the soil weight, soil internal friction angle, soil cohesion and retaining wall height to obtain the equivalent internal friction angle of the soil; calculating the angle between the internal sliding surface of the abandoned soil and the horizontal plane based on the angle between the soil-rock contact surface and the vertical line, the soil-rock contact surface friction angle, the equivalent internal friction angle of the soil and the slope angle of the spoil dump; and calculating the soil pressure at the soil-rock contact surface based on the preset angle critical value and the angle between the internal sliding surface of the abandoned soil and the horizontal plane using Coulomb's earth pressure theory.

[0007] In an optional embodiment, based on a preset angle critical value and the angle between the internal sliding surface of the discarded soil and the horizontal plane, the Coulomb earth pressure theory is used to calculate the soil pressure at the soil-rock contact surface, including: when the angle between the internal sliding surface of the discarded soil and the horizontal plane is greater than or equal to the preset angle critical value, determining that the sliding soil fill surface is a plane fill surface; calculating the active earth pressure coefficient when the sliding soil fill surface is a plane fill surface based on the equivalent internal friction angle of the soil, the angle between the soil-rock contact surface and the vertical line, the soil-rock contact surface friction angle and the slope angle of the spoil dump; calculating the first active earth pressure based on the active earth pressure coefficient, the soil weight and the height of the retaining wall; and using the first active earth pressure as the soil-rock contact surface earth pressure.

[0008] In an optional embodiment, based on a preset angle critical value and the angle between the internal sliding surface of the abandoned soil and the horizontal plane, the soil pressure at the soil-rock contact surface is calculated using the Coulomb earth pressure theory, and also includes: when the angle between the internal sliding surface of the abandoned soil and the horizontal plane is less than the preset angle critical value, determining that the sliding soil fill surface is a broken line fill surface; converting the broken line fill surface into a plane fill surface to calculate the equivalent retaining wall height of the corresponding triangular equivalent sliding soil; determining the retaining wall height equivalent coefficient based on the retaining wall height and the equivalent retaining wall height; calculating the second active earth pressure when the sliding soil fill surface is a broken line fill surface based on the retaining wall height equivalent coefficient and the first active earth pressure; and using the second active earth pressure as the soil pressure at the soil-rock contact surface.

[0009] In an optional embodiment, the broken line fill surface is converted into a plane fill surface to calculate the equivalent retaining wall height of the corresponding triangular equivalent sliding soil body, including: determining the quadrilateral actual sliding soil body in the discarded soil body based on the angle between the sliding surface inside the discarded soil body and the horizontal plane; converting the quadrilateral actual sliding soil body into a triangular equivalent sliding soil body with a plane fill surface; and calculating the equivalent retaining wall height of the triangular equivalent sliding soil body under the condition that the area of ​​the actual sliding soil body is equal to the area of ​​the triangular equivalent sliding soil body.

[0010] In an optional embodiment, based on the earth pressure of the soil-rock contact surface, the friction angle of the soil-rock contact surface, the angle between the soil-rock contact surface and the vertical line, and the weight of the soil, the amount of soil required for the slope foot counterpressure platform when the three-dimensional space extension dimension is 1 meter is calculated, including: based on the earth pressure of the soil-rock contact surface and the friction angle of the soil-rock contact surface, calculating the friction force applied to the rock block when the composite slope of the spoil dump has an arc-shaped sliding trend; under the condition of force balance on the soil-rock contact surface, based on the friction force, the angle between the soil-rock contact surface and the vertical line, and the weight of the soil, calculating the amount of soil required for the slope foot counterpressure platform when the three-dimensional space extension dimension is 1 meter.

[0011] In an optional embodiment, the geometric parameters of the slope foot counter-pressure platform are calculated based on the amount of soil pile, the slope angle of the spoil dump, and the angle between the soil-rock contact surface and the vertical line, including: calculating the height of the slope foot counter-pressure platform based on the amount of soil pile, the slope angle of the spoil dump, and the angle between the soil-rock contact surface and the vertical line; calculating the width of the slope foot counter-pressure platform based on the amount of soil pile and the height of the slope foot counter-pressure platform.

[0012] In a second aspect, the present invention provides a device for determining a back pressure platform for preventing and controlling coal fires in open-pit mines, comprising: an acquisition module for acquiring geometric parameters of a two-dimensional cross-section of a composite slope of a spoil dump and physical and mechanical parameters of the discarded soil; wherein the geometric parameters include: the angle between the soil-rock contact surface and the vertical line, the slope angle of the spoil dump slope and the height of the retaining wall; the physical and mechanical parameters include: soil weight, soil internal friction angle, soil-rock contact surface friction angle and soil cohesion; a first calculation module for calculating the soil pressure at the soil-rock contact surface based on Coulomb's earth pressure theory, geometric parameters and physical and mechanical parameters; a second calculation module for calculating the soil pressure at the soil-rock contact surface based on Coulomb's earth pressure theory, geometric parameters and physical and mechanical parameters; and a second calculation module for calculating the soil pressure at the soil-rock contact surface based on Coulomb's earth pressure theory, geometric parameters and physical and mechanical parameters. The block is used to calculate the amount of earth piled required for the slope foot counter-pressure platform when the three-dimensional space extension size is 1 meter based on the earth pressure of the soil-rock contact surface, the friction angle of the soil-rock contact surface, the angle between the soil-rock contact surface and the vertical line, and the weight of the soil; among them, the slope foot counter-pressure platform is used to weaken the shear effect of the composite slope of the spoil dump on the slope foot area; the third calculation module is used to use the two-dimensional cross-section as a parallelogram and the platform slope angle as the slope angle of the spoil dump slope as the geometric morphological conditions of the slope foot counter-pressure platform, and calculate the geometric parameters of the slope foot counter-pressure platform based on the amount of earth piled, the slope angle of the spoil dump slope and the angle between the soil-rock contact surface and the vertical line.

[0013] In a third aspect, the present invention provides an electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, it implements the method for determining the back pressure platform for preventing and controlling coal fire areas in open-pit mines as described in any one of the aforementioned embodiments.

[0014] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer instructions, which, when executed by a processor, implements the back pressure platform determination method for preventing and controlling open-pit mine coal fire areas described in any one of the aforementioned embodiments.

[0015] In response to the problem of controlling the induced coal fire zone in the spoil dump, the present invention proposes setting up a back-pressure platform at the toe of the slope as a control measure. First, the soil pressure at the soil-rock contact surface is calculated based on the Coulomb earth pressure theory, the geometric parameters of the two-dimensional section of the composite slope of the spoil dump, and the physical and mechanical parameters of the discarded soil. Then, with the purpose of weakening the shear effect of the composite slope of the spoil dump on the toe area, the amount of soil piled required for the back-pressure platform at the toe of the composite slope of the spoil dump is calculated when the three-dimensional space extension size is 1 meter. Finally, the two-dimensional section is a parallelogram, and the platform slope angle is the slope angle of the spoil dump slope as the geometric morphological conditions of the back-pressure platform at the toe of the slope. According to the amount of soil piled, the slope angle of the spoil dump slope and the angle between the soil-rock contact surface and the vertical line, the geometric parameters of the back-pressure platform at the toe of the slope are calculated. The method of setting up a counter-pressure platform at the foot of the spoil dump slope of the present invention can, on the one hand, improve the stability of the slope; on the other hand, it can weaken the shearing effect of the spoil dump slope on the toe of the slope, inhibit the displacement of the soil and rock strata at the toe of the slope, thereby reducing the development of cracks and lowering air permeability, thereby effectively curbing the combustion and spread of coal seams. Compared with other coal fire control measures, this method is low-cost, and the construction process is simple and feasible, with broad application prospects. In addition, before the coal fire zone is formed, a counter-pressure platform can be constructed in advance as a preventive measure, thereby effectively reducing the risk of the occurrence of coal fire zones. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A flow chart of a method for determining a back pressure platform for preventing and controlling coal fires in open pit mines provided by an embodiment of the present invention;

[0018] Figure 2 A schematic diagram of a two-dimensional cross-section of a composite slope of a spoil dump provided by an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the common geometric shapes of soil piled at the foot of the slope;

[0020] Figure 4 A diagram of a soil pressure calculation model based on a two-dimensional cross-section of a composite slope of a spoil dump provided in an embodiment of the present invention;

[0021] Figure 5 A diagram showing a calculation model of a slope foot back pressure platform provided in an embodiment of the present invention;

[0022] Figure 6A slope numerical analysis model and a schematic diagram of monitoring line positions provided by an embodiment of the present invention;

[0023] Figure 7 The displacement distribution characteristic diagram of each monitoring line before the back pressure platform at the foot of the slope is set up;

[0024] Figure 8 This is the displacement distribution characteristic diagram of the monitoring line after the back pressure platform at the foot of the slope is set up;

[0025] Figure 9 A functional module diagram of a device for determining a back pressure platform for preventing and controlling coal fires in open-pit mines provided by an embodiment of the present invention;

[0026] Figure 10 A schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0029] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0030] In order to solve the problem of induced coal fire zone in the spoil dump, the embodiment of the present invention proposes to set up a back pressure platform at the foot of the slope of the spoil dump as a control measure. The traditional spoil dump slope pressure foot treatment is mainly used to improve the stability of the slope. Its design usually takes the slope safety factor as the optimization target to determine the amount of soil pile at the foot of the slope and the geometric parameters of the back pressure platform. The back pressure platform design of the embodiment of the present invention is intended to weaken the shearing effect of the spoil dump slope on the shallow rock layer at the foot of the slope, thereby suppressing the expansion of the coal fire zone. Due to the different goals of the pressure foot design, the standards for determining the amount of soil pile at the foot of the slope are also different. The embodiment of the present invention needs to derive the geometric parameters of the back pressure platform at the foot of the slope based on the soil pressure theory to achieve the corresponding control effect.

[0031] Example 1

[0032] Figure 1 A flowchart of a method for determining a back pressure platform for preventing and controlling coal fires in open-pit mines provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the method specifically includes the following steps:

[0033] Step S102: obtaining the geometric parameters of the two-dimensional cross-section of the composite slope of the dump and the physical and mechanical parameters of the dumped soil.

[0034] To facilitate theoretical calculations and the use of Coulomb's earth pressure theory, the following assumptions are made in the implementation of the present invention: the sliding soil mass is considered a rigid body in a state of limit equilibrium; the sliding surface is assumed to be a plane when calculating active earth pressure; and since the research focuses on the stress characteristics of the coal seam and overlying rock strata, and a certain safety reserve factor is considered, the rock mass is assumed to be a rigid retaining wall with a height equal to the depth of the coal seam floor. Furthermore, the influence of the dump step is temporarily ignored in the theoretical analysis.

[0035] Figure 2 A schematic diagram of a two-dimensional cross-section of a composite slope of a spoil dump provided by an embodiment of the present invention. Figure 2 In the process, the covered mining slope can be regarded as a rigid retaining wall with an inclined wall back due to its greater rigidity, while the spoil dump slope can be regarded as the soil behind the wall. In order to ensure the stability of the spoil dump slope, its spoil height is often strictly limited, so the fill surface is in a broken line shape.

[0036] The geometric parameters of the two-dimensional cross-section of the composite slope of the dump include: the angle α between the soil-rock contact surface and the vertical line, the slope angle β of the dump (i.e., the inclination angle between the fill surface and the horizontal plane), and the height of the retaining wall H (i.e., the buried depth of the coal seam floor); the physical and mechanical parameters of the dumped soil include: soil weight γ, soil internal friction angle , soil-rock contact surface friction angle and soil cohesion c. The soil-rock contact surface represents the contact surface between the abandoned soil and the rock mass, and the soil-rock contact surface friction angle That is, the friction angle between the back of the retaining wall and the abandoned soil. Its value is generally determined by experiments. When there is no experimental data, it is generally taken as (1 / 3~2 / 3).

[0037] Step S104: Calculate the soil-rock interface earth pressure based on Coulomb's earth pressure theory, geometric parameters, and physical and mechanical parameters.

[0038] The angle between the sliding surface inside the known abandoned soil and the horizontal plane The change of determines the shape of the filling surface of the sliding soil. When , the fill surface is flat; when When , the fill surface is in the shape of a broken line, among which, represents the critical value of the angle between the sliding surface within the soil and the horizontal plane, denoted as the preset critical angle value. Furthermore, the calculation methods for the soil-rock interface earth pressure differ for different fill surface shapes. Therefore, embodiments of the present invention first determine whether the sliding fill surface is a planar fill surface or a broken line fill surface based on the aforementioned geometric parameters and physical and mechanical parameters. Then, based on the actual shape of the sliding fill surface, the soil-rock interface earth pressure is calculated according to Coulomb's earth pressure theory.

[0039] Step S106 , based on the earth pressure at the soil-rock interface, the friction angle at the soil-rock interface, the angle between the soil-rock interface and the vertical line, and the soil weight, calculate the amount of soil required when the slope foot counterpressure platform extends 1 meter in three-dimensional space.

[0040] Among them, the slope foot counter-pressure platform is used to weaken the shear effect of the composite slope of the spoil dump on the slope foot area.

[0041] When setting up a back pressure platform at the foot of the slope, it is crucial to properly control the amount of soil piled. Too much soil pile may cause damage to the slope along the soil-rock contact surface and increase the cost of the project; while too little soil pile cannot effectively weaken the shear effect of the slope and it is difficult to suppress the spread of coal fire. Therefore, after calculating the earth pressure at the soil-rock contact surface, the embodiment of the present invention takes the force balance of the soil-rock contact surface as a prerequisite, and calculates the amount of soil pile required for the back pressure platform at the foot of the slope when the extension size is 1 meter in three-dimensional space under the conditions of coal fire prevention and control according to the earth pressure at the soil-rock contact surface, the friction angle of the soil-rock contact surface, the angle between the soil-rock contact surface and the vertical line, and the weight of the soil, so as to provide a theoretical basis for the reasonable design of the back pressure platform at the foot of the slope.

[0042] In an embodiment of the present invention, when calculating the volume of any space, the default three-dimensional space extension size is 1 meter. Based on this, the volume of each space is numerically equal to the area of ​​its corresponding two-dimensional cross-section, which facilitates the calculation of multiple parameters.

[0043] In step S108, the two-dimensional cross-section is a parallelogram, and the platform slope angle is the slope angle of the spoil dump side slope as the geometric conditions of the slope foot counter-pressure platform. Based on the amount of soil piled, the slope angle of the spoil dump side slope, and the angle between the soil-rock contact surface and the vertical line, the geometric parameters of the slope foot counter-pressure platform are calculated.

[0044] Specifically, Figure 3 This is a schematic diagram of the common geometric shapes of soil accumulation at the foot of the slope, such as Figure 3As shown, the geometric shapes include: triangle, trapezoid, parallelogram. In theoretical analysis, the sliding soil and rock mass are idealized as rigid bodies. However, in actual engineering, these materials exhibit elastic-plastic characteristics. The shear effect of the spoil dump slope will gradually decay as it moves away from the toe of the slope. Therefore, the piled soil should be as close to the toe of the slope as possible to minimize the upward displacement of the rock layer. From a mechanical point of view, the centroid of the trapezoidal pile is far away from the toe of the slope, which will impose a large additional bending moment on the stratified rock mass near the toe of the slope, which is not conducive to controlling the displacement of the rock layer and leads to a higher demand for soil pile and a larger floor area, which does not conform to the design principle of land saving and loss reduction in open-pit mines. In addition, under the same soil pile volume conditions, the triangular pile occupies a larger area, which may affect the efficiency of space utilization. In summary, the parallelogram pile performs better in terms of soil pile volume, displacement control effect and floor area optimization, and is a more reasonable choice. Therefore, in the embodiment of the present invention, the shape of the slope foot back pressure platform is designed to be a parallelogram, and the platform slope angle is taken from the slope angle of the spoil dump slope.

[0045] After calculating the amount of soil piled required when the toe counter-pressure platform extends 1 meter in three-dimensional space, the value of the soil piled amount can be used as the area of ​​the toe counter-pressure platform in the two-dimensional section. Next, based on the slope angle of the spoil dump side slope and the angle between the soil-rock contact surface and the vertical line, the relationship between the width and height of the toe counter-pressure platform can be constructed. Then, combining the product of the width and height equals the area, the width and height of the toe counter-pressure platform, that is, the geometric parameters of the toe counter-pressure platform, can be calculated.

[0046] In response to the problem of controlling the induced coal fire zone in the spoil dump, an embodiment of the present invention proposes setting up a back-pressure platform at the toe of the slope as a control measure. First, the soil pressure at the soil-rock contact surface is calculated based on the Coulomb earth pressure theory, the geometric parameters of the two-dimensional cross-section of the composite slope of the spoil dump, and the physical and mechanical parameters of the discarded soil. Then, with the purpose of weakening the shear effect of the composite slope of the spoil dump on the toe area, the amount of soil piled required for the back-pressure platform at the toe of the composite slope of the spoil dump is calculated when the three-dimensional space extension size is 1 meter. Finally, the two-dimensional cross-section is a parallelogram, and the platform slope angle is the slope angle of the spoil dump slope as the geometric morphological conditions of the back-pressure platform at the toe of the slope. According to the amount of soil piled, the slope angle of the spoil dump slope, and the angle between the soil-rock contact surface and the vertical line, the geometric parameters of the back-pressure platform at the toe of the slope are calculated. The method of setting up a counter-pressure platform at the foot of the spoil dump slope of the present invention can, on the one hand, improve the stability of the slope; on the other hand, it can weaken the shearing effect of the spoil dump slope on the toe of the slope, inhibit the displacement of the soil and rock strata at the toe of the slope, thereby reducing the development of cracks and lowering air permeability, thereby effectively curbing the combustion and spread of coal seams. Compared with other coal fire control measures, this method is low-cost, and the construction process is simple and feasible, with broad application prospects. In addition, before the coal fire zone is formed, a counter-pressure platform can be constructed in advance as a preventive measure, thereby effectively reducing the risk of the occurrence of coal fire zones.

[0047] In an optional embodiment, the above step S104 calculates the soil pressure at the soil-rock interface based on Coulomb's earth pressure theory, geometric parameters, and physical and mechanical parameters, and specifically includes the following steps:

[0048] Step S1041 : Using the equivalent internal friction angle method, soil weight, soil internal friction angle, soil cohesion, and retaining wall height are processed to obtain the equivalent internal friction angle of the soil.

[0049] Step S1042: Calculate the angle between the internal sliding surface of the spoiled soil and the horizontal plane based on the angle between the soil-rock contact surface and the vertical line, the soil-rock contact surface friction angle, the equivalent internal friction angle of the soil, and the slope angle of the spoil dump.

[0050] Step S1043 , based on the preset angle critical value and the angle between the sliding surface inside the discarded soil and the horizontal plane, the soil pressure at the soil-rock contact surface is calculated using Coulomb's earth pressure theory.

[0051] Since the discarded soil comes from a loose mixture of soil and rock stripped from open-pit mining, although its natural cohesion is relatively small, it has undergone a certain degree of compaction during the soil discharge process and still has non-negligible cohesion. However, the embodiment of the present invention needs to calculate the active earth pressure at the soil-rock contact surface (referred to as the soil-rock contact surface earth pressure) based on the Coulomb's earth pressure theory. Since the traditional Coulomb's earth pressure coefficient can only calculate the case where the soil cohesion c=0 and the fill surface is a plane. For the working conditions where the fill surface is irregular and the soil cohesion c>0, there is no direct Coulomb's earth pressure calculation formula. Therefore, the embodiment of the present invention needs to first use the equivalent internal friction angle method to perform equivalent treatment on the cohesion, and then use the Coulomb's earth pressure theory.

[0052] Specifically, users need to use the corresponding equivalent internal friction angle formula based on actual working conditions. For example, for a soil-rock mixture with a retaining wall height greater than 30 meters and low cohesion, the equivalent internal friction angle formula proposed by Meyerhof can be used: .in, represents the internal friction angle of soil, represents the soil cohesion, Indicates soil weight. Indicates the height of the retaining wall, represents the equivalent internal friction angle of soil.

[0053] Next, assuming that the slope of the dump is a plane, the angle between the sliding surface inside the soil and the horizontal plane is calculated using the traditional Coulomb active earth pressure coefficient. Calculation formula to calculate the angle Value: Obviously, when the angle between the soil-rock contact surface and the vertical line is known , soil-rock contact surface friction angle , soil equivalent internal friction angle and the slope angle of the spoil dump In the case of , substitute the above formula to solve the angle between the sliding surface inside the abandoned soil and the horizontal plane: .

[0054] Calculate the angle between the sliding surface inside the spoil body and the horizontal plane Afterwards, as described above, it is necessary to first determine whether the sliding soil fill surface is a plane fill surface or a broken line fill surface based on the comparison result with the preset angle critical value, and then calculate the soil pressure at the soil-rock contact surface based on the actual shape of the sliding soil fill surface according to the Coulomb earth pressure theory.

[0055] In an optional embodiment, step S1043 calculates the soil-rock contact surface earth pressure using Coulomb's earth pressure theory based on a preset angle threshold and the angle between the sliding surface inside the discarded soil and the horizontal plane, specifically including the following steps:

[0056] Step S1043a: When the angle between the sliding surface inside the discarded soil body and the horizontal plane is greater than or equal to a preset angle critical value, the filling surface of the sliding soil body is determined to be a planar filling surface.

[0057] Step S1043b, based on the soil equivalent internal friction angle, the angle between the soil-rock contact surface and the vertical line, the soil-rock contact surface friction angle and the slope angle of the spoil dump, calculate the active earth pressure coefficient when the sliding soil fill surface is a planar fill surface.

[0058] Step S1043c: Calculate the first active earth pressure based on the active earth pressure coefficient, soil weight, and retaining wall height.

[0059] Step S1043d: Using the first active earth pressure as the earth pressure at the soil-rock contact surface.

[0060] Specifically, when the sliding soil fill surface is a planar fill surface, the embodiment of the present invention directly adopts Formula 1: Calculating the active earth pressure coefficient , and using Formula 2: Calculate the Coulomb active earth pressure of cohesive soil, recorded as the first active earth pressure When the sliding soil fill surface is a plane fill surface, the soil-rock contact surface earth pressure .

[0061] In an optional embodiment, the above step S1043, which calculates the earth pressure at the soil-rock interface using Coulomb's earth pressure theory based on a preset angle critical value and the angle between the sliding surface inside the discarded soil and the horizontal plane, further includes the following steps:

[0062] Step S10431: When the angle between the sliding surface inside the discarded soil body and the horizontal plane is less than a preset angle critical value, the filling surface of the sliding soil body is determined to be a broken line filling surface.

[0063] Step S10432: converting the broken line fill surface into a plane fill surface to calculate the equivalent retaining wall height of the corresponding triangular equivalent sliding soil body.

[0064] Step S10433: Determine the retaining wall height equivalent coefficient based on the retaining wall height and the equivalent retaining wall height.

[0065] Step S10434: Calculate the second active earth pressure when the sliding soil fill surface is a broken line fill surface based on the retaining wall height equivalent coefficient and the first active earth pressure.

[0066] Step S10435: Using the second active earth pressure as the soil-rock contact surface earth pressure.

[0067] Specifically, when the sliding soil fill surface is a broken line fill surface, the above formula 2 cannot be used directly to calculate the active earth pressure. It is necessary to first treat the broken line fill surface as a plane fill surface. Figure 4 The above equivalent treatment is to equate the quadrilateral sliding soil COBD to the triangular sliding soil A'OB'. After the equivalent treatment, the equivalent retaining wall height of the triangular equivalent sliding soil can be calculated based on the condition that the areas before and after the equivalent are equal. , and then use the following formula to calculate the equivalent coefficient of retaining wall height: .

[0068] Substituting the equivalent retaining wall height for the retaining wall height in Formula 2 above, we can obtain Formula 3: That is to say, after calculating the equivalent coefficient of the retaining wall height, the Coulomb active earth pressure of the cohesive soil when the sliding soil fill surface is a broken line fill surface can be obtained by multiplying the square of the equivalent coefficient of the retaining wall height by the first active earth pressure, which is recorded as the second active earth pressure When the sliding soil fill surface is a broken line fill surface, the soil-rock contact surface earth pressure .

[0069] In an optional implementation, the above step S10432, converting the broken line fill surface into a plane fill surface to calculate the equivalent retaining wall height of the corresponding triangular equivalent sliding soil body, specifically includes the following steps:

[0070] Step S104321: Determine the quadrilateral actual sliding soil body in the discarded soil body based on the angle between the sliding surface inside the discarded soil body and the horizontal plane.

[0071] Step S104322: convert the quadrilateral actual sliding soil body into a triangular equivalent sliding soil body with a flat fill surface.

[0072] Step S104323: Calculate the equivalent retaining wall height of the triangular equivalent sliding soil body under the condition that the area of ​​the actual sliding soil body is equal to the area of ​​the triangular equivalent sliding soil body.

[0073] Specifically, refer to Figure 4 , in determining the angle between the sliding surface inside the abandoned soil and the horizontal plane Afterwards, you can determine Figure 4 The position of point C in the middle of the dump soil is then determined, and the quadrilateral actual sliding soil mass in the dump soil mass is determined as COBD. Converting this to a plane with the fill surface, the triangular equivalent sliding soil mass A'OB' is obtained.

[0074] The embodiment of the present invention calculates the equivalent retaining wall height of the triangular equivalent sliding soil body under the condition that the area of ​​the quadrilateral actual sliding soil body is equal to the area of ​​the triangular equivalent sliding soil body. Therefore, it is necessary to determine the expression of the area of ​​the actual sliding soil body and the expression of the area of ​​the triangular equivalent sliding soil body respectively.

[0075] The area of ​​the actual sliding soil COBD is the difference between the area of ​​triangle AOB and the area of ​​triangle ACD, which can be expressed as: Therefore, the next step is to calculate the area of ​​triangle AOB separately and the area of ​​triangle ACD .

[0076] pass Figure 4 It can be seen that , Indicates the length of the CD segment, represents the height of triangle ACD, which can be calculated using the law of sines: ,in, Indicates the length of the DO segment, and then the , in the above formula It can also be calculated according to the law of sine: , substitute The formula can be obtained: .

[0077] pass Figure 4 It can be seen that ,in, Indicates the length of AB segment, represents the height of triangle AOB, which can be calculated according to the law of sine: , , substitute the two into The formula can be obtained: .

[0078] From this we can get, .

[0079] As A'B' is parallel to AB, the area of ​​triangle A'OB' can be calculated in the same way as the area of ​​triangle AOB. Simply replace H in the area formula of triangle AOB with That is, the area of ​​triangle A'OB' .

[0080] Next, based on the condition that the equivalent front and back areas are equal: , the equivalent retaining wall height of the triangular equivalent sliding soil can be calculated: , that is, the equivalent coefficient of retaining wall height: .

[0081] In an optional embodiment, step S106 calculates the amount of earth pile required when the toe counter-pressure platform has a three-dimensional extension of 1 meter based on the earth pressure at the soil-rock interface, the friction angle at the soil-rock interface, the angle between the soil-rock interface and the vertical line, and the soil weight, and specifically includes the following steps:

[0082] Step S1061 , based on the earth pressure and the friction angle of the soil-rock contact surface, calculate the friction force applied to the rock mass when the composite slope of the spoil dump has an arc-shaped sliding trend.

[0083] Step S1062: Calculate the amount of soil required for the slope foot counterpressure platform to extend 1 meter in three-dimensional space based on the friction force, the angle between the soil-rock contact surface and the vertical line, and the weight of the soil, with the force balance of the soil-rock contact surface as the condition.

[0084] Specifically, refer to Figure 5 The composite slope of the spoil dump exerts a normal force on the rock mass at the soil-rock interface. and friction . When the composite slope of the spoil dump has an arc-shaped sliding trend, the sliding soil tends to move upward relative to the mining slope. In this process, the sliding soil exerts an upward friction force on the rock mass of the mining slope through the soil-rock contact surface, thereby inducing a shear effect in the slope foot area, causing the rock mass to move upward. In actual engineering, this shear effect may cause deformation and damage to the overlying rock strata of the coal seam. In order to reduce the upward displacement of the slope foot and reduce the impact of the shear action on the overlying rock strata of the coal seam, an embodiment of the present invention sets a back pressure platform at the slope foot. The amount of soil piled on the back pressure platform is calculated based on the friction force exerted on the rock mass by the composite slope of the spoil dump. In order to simplify the calculation and ensure safety reserves, it is assumed that the soil-rock contact surface above the coal seam floor has a relative movement trend, and the friction force is calculated based on the sliding friction force under the limit state. According to Figure 4The direction of the force shown in the figure is used to decompose the earth pressure at the soil-rock interface. It can be seen that the normal force applied to the rock mass when the composite slope of the spoil dump has an arc-shaped sliding trend is The friction force applied to the rock mass when the composite slope of the spoil dump experiences an arc-shaped sliding trend .

[0085] In order to balance the forces on the soil-rock interface, the component of the gravity of the slope foot counterpressure platform in the opposite direction to the friction force should be Should Equal, that is, ,and , G represents the gravity of the back pressure platform at the foot of the slope, , represents the amount of soil (i.e., volume) required when the back pressure platform at the foot of the slope extends 1 meter in three-dimensional space. Thus, . Transforming this formula, we can get: the amount of soil piled In other words, after calculating the friction force, the amount of soil required to form a 1-meter three-dimensional counter-pressure platform at the toe of the slope can be further calculated based on the friction force, the angle between the soil-rock contact surface and the vertical line, and the soil weight.

[0086] In an optional embodiment, in the above step S108, the geometric parameters of the back pressure platform at the toe of the slope are calculated based on the amount of soil piled, the slope angle of the spoil dump, and the angle between the soil-rock contact surface and the vertical line, which specifically includes the following steps:

[0087] Step S1081: Calculate the height of the back pressure platform at the toe of the slope based on the amount of soil piled, the slope angle of the spoil dump, and the angle between the soil-rock contact surface and the vertical line.

[0088] Step S1082: Calculate the width of the slope foot counter-pressure platform based on the amount of soil piled and the height of the slope foot counter-pressure platform.

[0089] according to Figure 5 It can be seen that if the height of the slope foot counter-pressure platform is , with a width of , then: , and from the description above, we can know that the value of the soil pile is equal to the area of ​​the slope foot counter-pressure platform in the two-dimensional section, that is, V = bh. Therefore, the height of the slope foot counter-pressure platform is: , the width of the back pressure platform at the foot of the slope is .

[0090] In summary, the method of setting a back-pressure platform at the toe of the composite slope of the spoil dump proposed in the embodiment of the present invention can, on the one hand, improve the stability of the slope; on the other hand, it can weaken the shearing effect of the spoil dump slope on the toe, inhibit the displacement of the soil and rock formations at the toe, so as to reduce the development of cracks and reduce air permeability, thereby effectively curbing further combustion of the coal seam. Compared with other coal fire control measures, this method has low cost and convenient material acquisition. The waste soil accumulated in the spoil dump can be directly used as the pressure material. The construction process is simple and feasible, and has broad application prospects. In addition, before the coal fire zone is formed, a back-pressure platform can be constructed in advance as a preventive measure to effectively reduce the risk of coal fire zones.

[0091] To verify the performance of the method provided by the embodiments of the present invention, an induced coal fire zone in a mine dump was treated with reference to the embodiments of the present invention. The geometric parameters of the slope foot counterpressure platform were designed, and simulation analysis was performed using FLAC3D. The displacement and stress distribution characteristics before and after the pressure foot were compared, with a focus on monitoring the displacement changes of the overlying rock strata in the coal seam. This verified the inhibitory effect of the slope pressure foot measures on the formation of the coal fire zone and further evaluated the rationality of the formula for calculating the amount of soil piled at the slope foot. The height and width of the counterpressure platform were calculated by combining historical survey data with field measurement data.

[0092] To prevent and control the formation and spread of coal fires in this open-pit mine, it was calculated that a counter-pressure platform should be set up in the unburned area of ​​the coal seam at the foot of the dump slope. The platform height is 17.72m and the platform width is 74.52m. To verify the rationality and effectiveness of the pressure foot calculation formula proposed in this study, a FLAC3D model of the open-pit mine dump slope was established. The displacement of the overlying rock strata on the coal seam at the foot of the slope was analyzed before and after the soil was piled at the slope foot. Three monitoring profiles (M1, M2, and M3) were set up above the coal seam in the potential coal fire area to quantify the rock strata displacement characteristics at different locations. The model and monitoring line locations are shown in the figure. Figure 6 In the numerical analysis, the rock mechanical parameters of each formation are shown in Table 1 below.

[0093] Table 1 Rock mechanical parameters of various formations

[0094]

[0095] Figure 7This is a characteristic diagram of the displacement distribution of each monitoring line before the back pressure platform was established at the toe of the slope. The results show that the rock strata within the potential coal fire zone exhibit an overall upward displacement trend, with the displacement gradually decreasing with depth and turning negative at a certain depth, indicating downward displacement. The surface loose layer exhibits the largest displacement, primarily due to its low mechanical strength and significant plastic deformation. The upward displacement of the M3 monitoring line, located farther from the toe of the slope, within the surface loose layer is slightly greater than that of the M1 monitoring line located closer to the toe of the slope. However, at depths of 15–30 m (within the hard rock layer), the displacement of the M3 monitoring profile is smaller than that of the M1 monitoring profile. This indicates that in harder rock layers, the shear effect of the spoil dump slope gradually decreases from the toe of the slope toward the distal end. Furthermore, because the theoretical analysis assumes a rigid rock slope, while the actual slope exhibits elastic-plastic properties, the simulation results for the surface loose layer differ somewhat from the theoretical analysis.

[0096] Figure 8 This is a characteristic diagram of the displacement distribution of the monitoring lines after the backpressure platform was installed at the toe of the slope. The results show that the displacement of monitoring line M1 is essentially zero within the depth range of 0–30 m, indicating that in the rock layer area near the soil-rock interface, the deadweight of the surface accumulated soil effectively weakens the shear effect of the spoil dump slope on the original mining slope. This further verifies the rationality of the formula for calculating the amount of soil piled at the toe of the slope derived in this embodiment of the present invention. Monitoring line M2 still exhibits some displacement in the shallow rock layer, but it is significantly reduced compared to before soil piled. This is mainly because the shallow rock layer is composed of weak and loose layers, which undergo significant plastic deformation under the influence of the accumulated soil load. In addition, M3 is located at the toe of the accumulated slope. The accumulated soil itself exerts a certain shear effect on the loose layers, resulting in a slight increase in the displacement of the shallow rock layer. However, this effect is limited to the shallow loose layers, and the displacement decreases rapidly with increasing depth. Within the depth range of 15–30 m, the rock layer displacement is significantly reduced compared to before soil piled. At this time, the overlying rock layers of the coal seam remain intact and the development of cracks is controlled, blocking the oxygen passage between the coal seam and the surface, thereby effectively curbing the formation and spread of coal fire zones.

[0097] Example 2

[0098] An embodiment of the present invention also provides a device for determining a back pressure platform for preventing and controlling coal fire zones in open-pit mines. The device is mainly used to execute the back pressure platform determination method for preventing and controlling coal fire zones in open-pit mines provided in the above-mentioned embodiment 1. The following is a detailed introduction to the back pressure platform determination device for preventing and controlling coal fire zones in open-pit mines provided in an embodiment of the present invention.

[0099] Figure 9 A functional module diagram of a device for determining a back pressure platform for preventing and controlling coal fires in open-pit mines provided by an embodiment of the present invention, such as Figure 9 As shown, the device mainly includes: an acquisition module 10, a first calculation module 20, a second calculation module 30, and a third calculation module 40, wherein:

[0100] Acquisition module 10 is used to obtain the geometric parameters of the two-dimensional cross-section of the composite slope of the spoil dump and the physical and mechanical parameters of the spoiled soil; wherein the geometric parameters include: the angle between the soil-rock contact surface and the vertical line, the slope angle of the spoil dump and the height of the retaining wall; the physical and mechanical parameters include: soil weight, soil internal friction angle, soil-rock contact surface friction angle and soil cohesion.

[0101] The first calculation module 20 is used to calculate the soil pressure at the soil-rock interface based on Coulomb's earth pressure theory, geometric parameters and physical and mechanical parameters.

[0102] The second calculation module 30 is used to calculate the amount of soil required for the slope foot counter-pressure platform when its three-dimensional extension size is 1 meter based on the soil pressure at the soil-rock interface, the friction angle at the soil-rock interface, the angle between the soil-rock interface and the vertical line, and the soil weight; wherein the slope foot counter-pressure platform is used to weaken the shear effect of the composite slope of the spoil dump on the slope foot area.

[0103] The third calculation module 40 is used to calculate the geometric parameters of the slope foot counter-pressure platform based on the amount of soil piled, the slope angle of the spoil dump side slope, and the angle between the soil-rock contact surface and the vertical line, taking the two-dimensional cross-section as a parallelogram and the platform slope angle as the slope angle of the spoil dump side slope as the geometric conditions of the slope foot counter-pressure platform.

[0104] In response to the problem of controlling the induced coal fire zone in the spoil dump, an embodiment of the present invention proposes setting up a back-pressure platform at the toe of the slope as a control measure. First, the soil pressure at the soil-rock contact surface is calculated based on the Coulomb earth pressure theory, the geometric parameters of the two-dimensional cross-section of the composite slope of the spoil dump, and the physical and mechanical parameters of the discarded soil. Then, with the purpose of weakening the shear effect of the composite slope of the spoil dump on the toe area, the amount of soil piled required for the back-pressure platform at the toe of the composite slope of the spoil dump is calculated when the three-dimensional space extension dimension is 1 meter. Finally, the two-dimensional cross-section is a parallelogram, and the platform slope angle is the slope angle of the spoil dump slope as the geometric morphological conditions of the back-pressure platform at the toe of the slope. According to the amount of soil piled, the slope angle of the spoil dump slope, and the angle between the soil-rock contact surface and the vertical line, the geometric parameters of the back-pressure platform at the toe of the slope are calculated. The embodiment of the present invention sets a back pressure platform at the foot of the slope of the spoil dump. On the one hand, it can improve the stability of the slope; on the other hand, it can weaken the shear effect of the spoil dump slope on the toe, inhibit the displacement of the soil and rock formations at the toe, reduce the development of cracks, reduce air permeability, and thus effectively curb the combustion and spread of coal seams. Compared with other coal fire control measures, the implementation cost of the embodiment of the present invention is low, and the construction process is simple and feasible, with broad application prospects. In addition, before the coal fire zone is formed, a back pressure platform can be constructed in advance as a preventive measure, thereby effectively reducing the risk of the occurrence of coal fire zones.

[0105] Optionally, the first calculation module 20 includes:

[0106] The processing unit is used to process the soil weight, soil internal friction angle, soil cohesion and retaining wall height using the equivalent internal friction angle method to obtain the soil equivalent internal friction angle.

[0107] The first calculation unit is used to calculate the angle between the internal sliding surface of the spoil soil and the horizontal plane based on the angle between the soil-rock contact surface and the vertical line, the soil-rock contact surface friction angle, the equivalent internal friction angle of the soil body and the slope angle of the spoil dump.

[0108] The second calculation unit is used to calculate the soil pressure at the soil-rock contact surface using Coulomb's earth pressure theory based on a preset angle critical value and the angle between the sliding surface inside the discarded soil and the horizontal plane.

[0109] Optionally, the second computing unit includes:

[0110] The first determining subunit is used to determine that the filling surface of the sliding soil body is a plane filling surface when the angle between the sliding surface inside the discarded soil body and the horizontal plane is greater than or equal to a preset angle critical value.

[0111] The first calculation subunit is used to calculate the active earth pressure coefficient when the sliding soil fill surface is a plane fill surface based on the equivalent internal friction angle of the soil, the angle between the soil-rock contact surface and the vertical line, the soil-rock contact surface friction angle and the slope angle of the spoil dump.

[0112] a second calculation subunit, for calculating a first active earth pressure based on an active earth pressure coefficient, soil weight, and a retaining wall height;

[0113] The second determining subunit is configured to use the first active earth pressure as the earth pressure at the soil-rock contact surface.

[0114] Optionally, the second computing unit further includes:

[0115] The third determining subunit is configured to determine that the filling surface of the sliding soil body is a broken line filling surface when the angle between the sliding surface inside the discarded soil body and the horizontal plane is less than a preset angle critical value.

[0116] The conversion and calculation subunit is used to convert the broken line fill surface into a plane fill surface to calculate the equivalent retaining wall height of the corresponding triangular equivalent sliding soil.

[0117] The fourth determining subunit is used to determine the retaining wall height equivalent coefficient based on the retaining wall height and the equivalent retaining wall height.

[0118] The third calculation subunit is used to calculate the second active earth pressure when the sliding soil fill surface is a broken line fill surface based on the retaining wall height equivalent coefficient and the first active earth pressure.

[0119] The fifth determining subunit is configured to use the second active earth pressure as the earth pressure at the soil-rock contact surface.

[0120] Optionally, the conversion and calculation subunit is specifically used to:

[0121] Based on the included angle between the sliding surface inside the abandoned soil and the horizontal plane, the actual sliding soil of the quadrilateral in the abandoned soil is determined.

[0122] The actual quadrilateral sliding soil mass is converted into a triangular equivalent sliding soil mass with a plane fill surface.

[0123] Under the condition that the area of ​​the actual sliding soil is equal to the area of ​​the triangular equivalent sliding soil, the equivalent retaining wall height of the triangular equivalent sliding soil is calculated.

[0124] Optionally, the second calculation module 30 is specifically configured to:

[0125] Based on the earth pressure and friction angle at the soil-rock interface, the friction force applied to the rock mass when the composite slope of the spoil dump exhibits an arc-shaped sliding trend is calculated.

[0126] Under the condition of force balance at the soil-rock contact surface, based on friction, the angle between the soil-rock contact surface and the vertical line, and the weight of the soil, the amount of soil required when the back pressure platform at the toe of the slope extends to 1 meter in three-dimensional space is calculated.

[0127] Optionally, the third calculation module 40 is specifically configured to:

[0128] The height of the back pressure platform at the toe of the slope is calculated based on the amount of soil piled, the slope angle of the spoil dump, and the angle between the soil-rock contact surface and the vertical line.

[0129] Calculate the width of the toe counterpressure platform based on the amount of soil piled and the height of the toe counterpressure platform.

[0130] Example 3

[0131] See also Figure 10 An embodiment of the present invention provides an electronic device, which includes: a processor 60, a memory 61, a bus 62 and a communication interface 63, wherein the processor 60, the communication interface 63 and the memory 61 are connected via the bus 62; the processor 60 is used to execute an executable module stored in the memory 61, such as a computer program.

[0132] Memory 61 may include high-speed random access memory (RAM) and may also include non-volatile memory, such as at least one disk drive. Communication between the system network element and at least one other network element is achieved via at least one communication interface 63 (which may be wired or wireless), and may utilize the Internet, a wide area network, a local area network, a metropolitan area network, or the like.

[0133] The bus 62 may be an ISA bus, a PCI bus, or an EISA bus. The bus may be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, Figure 10 Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0134] Among them, the memory 61 is used to store programs, and the processor 60 executes the program after receiving the execution instruction. The method executed by the device defined by the process disclosed in any embodiment of the above-mentioned embodiment of the present invention can be applied to the processor 60 or implemented by the processor 60.

[0135] The processor 60 may be an integrated circuit chip with signal processing capabilities. During implementation, the steps of the above method may be performed by hardware integrated logic circuits or software instructions within the processor 60. The processor 60 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of the present invention may be directly executed by a hardware decoding processor or by a combination of hardware and software modules within the decoding processor. The software modules may be located in storage media well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or the like. The storage medium is located in the memory 61 , and the processor 60 reads the information in the memory 61 and completes the steps of the above method in combination with its hardware.

[0136] An embodiment of the present invention provides a computer program product of a method and apparatus for determining a back pressure platform in an open-pit mine coal fire zone, comprising a computer-readable storage medium storing a non-volatile program code executable by a processor. The program code includes instructions that can be used to execute the method described in the previous method embodiment. For specific implementation, please refer to the method embodiment and will not be repeated here.

[0137] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0138] If the functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include various media capable of storing program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0139] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0140] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0141] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0142] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining a back pressure platform for preventing and controlling coal fires in open pit mines, characterized in that: include: Obtaining the geometric parameters of the two-dimensional cross-section of the composite slope of the spoil dump and the physical and mechanical parameters of the spoiled soil; wherein the geometric parameters include: the angle between the soil-rock interface and the vertical line, the slope angle of the spoil dump, and the height of the retaining wall; the physical and mechanical parameters include: soil weight, soil internal friction angle, soil-rock interface friction angle, and soil cohesion; Calculating the earth pressure at the soil-rock interface based on Coulomb's earth pressure theory, the geometric parameters, and the physical and mechanical parameters; Based on the earth pressure at the soil-rock interface, the friction angle at the soil-rock interface, the angle between the soil-rock interface and the vertical line, and the soil weight, the required amount of soil for the slope foot counter-pressure platform with a three-dimensional extension of 1 meter is calculated; wherein the slope foot counter-pressure platform is used to weaken the shear effect of the composite slope of the spoil dump on the slope foot area; The two-dimensional cross-section is a parallelogram, and the platform slope angle is the slope angle of the spoil dump side slope as the geometric shape condition of the slope foot counter-pressure platform. Based on the amount of soil piled, the slope angle of the spoil dump side slope, and the angle between the soil-rock contact surface and the vertical line, the geometric parameters of the slope foot counter-pressure platform are calculated; Calculating the soil-rock interface earth pressure based on Coulomb's earth pressure theory, the geometric parameters, and the physical and mechanical parameters includes: The soil weight, the soil internal friction angle, the soil cohesion and the retaining wall height are processed using an equivalent internal friction angle method to obtain an equivalent internal friction angle of the soil; Calculating the angle between the internal sliding surface of the spoiled soil and the horizontal plane based on the angle between the soil-rock contact surface and the vertical line, the friction angle of the soil-rock contact surface, the equivalent internal friction angle of the soil, and the slope angle of the spoil dump; Based on a preset angle critical value and the angle between the sliding surface inside the abandoned soil and the horizontal plane, the earth pressure at the soil-rock contact surface is calculated using Coulomb's earth pressure theory; Based on the earth pressure at the soil-rock interface, the friction angle at the soil-rock interface, the angle between the soil-rock interface and the vertical line, and the weight of the soil, the amount of soil required when the slope foot counterpressure platform has a three-dimensional extension of 1 meter is calculated, including: Calculating the friction force applied to the rock mass when the composite slope of the dump site exhibits an arc-shaped sliding trend based on the earth pressure at the soil-rock interface and the friction angle at the soil-rock interface; Under the condition of force balance at the soil-rock interface, based on the friction force, the angle between the soil-rock interface and the vertical line, and the weight of the soil, calculate the amount of soil required when the slope foot counterpressure platform extends 1 meter in three-dimensional space; Based on the amount of soil piled, the slope angle of the spoil dump, and the angle between the soil-rock contact surface and the vertical line, the geometric parameters of the slope foot counterpressure platform are calculated, including: Calculating the height of the slope foot counter-pressure platform based on the amount of soil piled, the slope angle of the spoil dump, and the angle between the soil-rock contact surface and the vertical line; The width of the slope foot counter-pressure platform is calculated based on the amount of soil pile and the height of the slope foot counter-pressure platform.

2. The method for determining the back pressure platform for preventing and controlling coal fires in open-pit mines according to claim 1, characterized in that: Based on the preset angle critical value and the angle between the sliding surface inside the abandoned soil and the horizontal plane, the soil pressure at the soil-rock interface is calculated using Coulomb's earth pressure theory, including: When the angle between the sliding surface inside the abandoned soil body and the horizontal plane is greater than or equal to the preset angle critical value, determining that the filling surface of the sliding soil body is a plane filling surface; Calculating the active earth pressure coefficient when the sliding soil fill surface is a planar fill surface based on the soil equivalent internal friction angle, the angle between the soil-rock contact surface and the vertical line, the soil-rock contact surface friction angle, and the slope angle of the spoil dump; Calculating a first active earth pressure based on the active earth pressure coefficient, the soil mass, and the retaining wall height; The first active earth pressure is used as the earth pressure at the soil-rock interface.

3. The method for determining the back pressure platform for preventing and controlling coal fire in open pit mines according to claim 2, characterized in that: Based on a preset angle critical value and the angle between the sliding surface inside the abandoned soil and the horizontal plane, the soil pressure at the soil-rock contact surface is calculated using Coulomb's earth pressure theory, further comprising: When the angle between the sliding surface inside the abandoned soil body and the horizontal plane is less than the preset angle critical value, determining that the filling surface of the sliding soil body is a broken line filling surface; Converting the broken-line fill surface into a plane fill surface to calculate the equivalent retaining wall height of the corresponding triangular equivalent sliding soil body; determining a retaining wall height equivalence coefficient based on the retaining wall height and the equivalent retaining wall height; Calculating a second active earth pressure when the sliding soil fill surface is a broken line fill surface based on the retaining wall height equivalent coefficient and the first active earth pressure; The second active earth pressure is used as the soil-rock contact surface earth pressure.

4. The method for determining the back pressure platform for preventing and controlling coal fires in open-pit mines according to claim 3, characterized in that: The broken line fill surface is converted into a plane fill surface to calculate the equivalent retaining wall height of the corresponding triangular equivalent sliding soil body, including: determining a quadrilateral actual sliding soil mass in the discarded soil mass based on an angle between a sliding surface inside the discarded soil mass and a horizontal plane; Converting the quadrilateral actual sliding soil mass into a triangular equivalent sliding soil mass with a plane fill surface; On the condition that the area of ​​the actual sliding soil body is equal to the area of ​​the triangular equivalent sliding soil body, the equivalent retaining wall height of the triangular equivalent sliding soil body is calculated.

5. A device for determining a back pressure platform for preventing and controlling coal fires in open-pit mines, characterized in that: include: An acquisition module is used to obtain the geometric parameters of the two-dimensional cross-section of the composite slope of the spoil dump and the physical and mechanical parameters of the spoiled soil; wherein the geometric parameters include: the angle between the soil-rock contact surface and the vertical line, the slope angle of the spoil dump, and the height of the retaining wall; the physical and mechanical parameters include: soil weight, soil internal friction angle, soil-rock contact surface friction angle, and soil cohesion; A first calculation module is used to calculate the earth pressure at the soil-rock interface based on Coulomb's earth pressure theory, the geometric parameters and the physical and mechanical parameters; A second calculation module is configured to calculate the amount of soil required for a toe counter-pressure platform with a three-dimensional extension of 1 meter based on the soil pressure at the soil-rock interface, the friction angle at the soil-rock interface, the angle between the soil-rock interface and a vertical line, and the soil mass; wherein the toe counter-pressure platform is configured to reduce the shearing effect of the composite slope of the spoil dump on the toe area; A third calculation module is configured to calculate the geometric parameters of the slope foot counter-pressure platform based on the amount of soil piled, the slope angle of the spoil dump side slope, and the angle between the soil-rock contact surface and the vertical line, taking the two-dimensional cross-section as a parallelogram and the platform slope angle as the slope angle of the spoil dump side slope as the geometric morphological conditions of the slope foot counter-pressure platform; The first calculation module includes: a processing unit for processing the soil weight, the soil internal friction angle, the soil cohesion and the retaining wall height using an equivalent internal friction angle method to obtain an equivalent internal friction angle of the soil; A first calculation unit is configured to calculate an angle between an internal sliding surface of the spoiled soil and a horizontal plane based on an angle between the soil-rock contact surface and a vertical line, a friction angle of the soil-rock contact surface, an equivalent internal friction angle of the soil, and a slope angle of the spoil dump; a second calculation unit, configured to calculate the earth pressure at the soil-rock contact surface using Coulomb's earth pressure theory based on a preset angle critical value and an angle between the sliding surface inside the discarded soil and the horizontal plane; The second calculation module is specifically used for: Calculating the friction force applied to the rock mass when the composite slope of the dump site exhibits an arc-shaped sliding trend based on the earth pressure at the soil-rock interface and the friction angle at the soil-rock interface; Under the condition of force balance at the soil-rock interface, based on the friction force, the angle between the soil-rock interface and the vertical line, and the weight of the soil, calculate the amount of soil required when the slope foot counterpressure platform extends 1 meter in three-dimensional space; The third calculation module is specifically used for: Calculating the height of the slope foot counter-pressure platform based on the amount of soil piled, the slope angle of the spoil dump, and the angle between the soil-rock contact surface and the vertical line; The width of the slope foot counter-pressure platform is calculated based on the amount of soil pile and the height of the slope foot counter-pressure platform.

6. An electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, wherein: When the processor executes the computer program, the method for determining a back pressure platform for preventing and controlling coal fire areas in open-pit mines according to any one of claims 1 to 4 is implemented.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the method for determining a back pressure platform for preventing and controlling coal fire zones in open-pit mines according to any one of claims 1 to 4 is implemented.

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