A method, terminal and storage medium for evaluating impact hazard of combined mining of inclined coal seams

Abstract

The present invention provides an impact hazard assessment method, an assessment terminal and a storage medium for joint mining of inclined coal seam groups, which belongs to the technical field of inclined coal seam mining, and determines the target research area of ​​the mining site, obtains the standard rock sample of the coal in the target area, and calculates its post-peak softening modulus; calculates the vertical compressive stress; calculates the ultimate strength and the related distance respectively; obtains the lateral support pressure attenuation; analyzes the advance support pressure in front of the mining site; based on the superposition of the disturbance stress of the advance support pressure and the overlying legacy coal pillar on the underlying coal seam, the stress after superposition is obtained; obtains the critical stress of rock burst; and determines the impact risk of mining the underlying coal seam according to the magnitude of the superimposed stress and the relationship with the critical stress of rock burst during mining of the underlying coal seam. The present invention avoids judging the influence of the overlying legacy section coal pillar on the mining of the underlying coal seam based on experience, and accurately evaluates the scope and degree of influence of the overlying legacy section coal pillar on the mining of the underlying coal seam.

Description

Technical Field

[0001] The present invention belongs to the technical field of inclined coal seam mining, and in particular relates to an impact hazard assessment method, an assessment terminal and a storage medium for combined mining of an inclined coal seam group. Background Art

[0002] At present, close-range coal seam groups and inclined coal seams are widespread and have rich reserves. However, most mines are restricted by the original mining technical conditions. When mining the overlying coal seams, they often leave segmental coal pillars of a certain width, which affect the mining of the underlying coal seams. Especially when the underlying coal seam has an impact tendency, the underlying coal seam is very likely to induce rock burst disasters due to the stress disturbance of the segmental coal pillars left over from the overlying coal seams.

[0003] How to correctly analyze the impact hazard of joint mining of overlying coal seams and underlying coal seams in inclined coal seam groups, minimize the mutual influence between inclined coal seam groups, and effectively evaluate the impact hazard degree of the residual coal pillars of the overlying inclined coal seams on the underlying inclined coal seams, thereby avoiding the occurrence of rock burst disasters, is of great significance to improving the coal recovery rate under complex conditions such as close-range coal seam groups and inclined coal seams, and ensuring safe production in mines.

[0004] In the prior art, relevant patents on methods for preventing and controlling rock bursts in coal seams under complex conditions of joint mining of multiple coal seams and methods for optimizing rock burst monitoring systems include: a comprehensive method for preventing and controlling rock bursts in mines with multiple coal seams, a method for preventing and controlling rock bursts in multiple coal seams by unloading pressure through ground drilling, a ground method for preventing and controlling rock bursts in close-range coal seam groups, an underground method for preventing and controlling rock bursts in coal seam groups, a method, system and storage medium for arranging coordinated mining of coal seam groups in mines with rock bursts, a method and system for setting up coal pillars in goafs of coal seam group mining mines, a zoning evaluation method for the rock layer structure of coal seams, mining areas or working face roofs, a method for preventing and controlling rock bursts in coal seam groups with large inclinations by reducing loads and levers, a real-time monitoring system and method for rock bursts and mine earthquakes, a multi-parameter early warning method for rock bursts based on fuzzy mathematics and microseismic monitoring, a method for monitoring the danger of rock bursts in underground coal mining, and a method for arranging a microseismic monitoring system for rock bursts, etc.

[0005] However, nowadays, construction sites often rely on engineering experience and adopt the method of mining the underlying coal seam at a certain distance from the overlying legacy coal pillar, or arrange a large number of pressure relief drill holes on site when mining the underlying coal seam to minimize the stress concentration during mining of the underlying coal seam, thereby avoiding the influence of the overlying legacy coal pillar during mining of the underlying coal seam. When mining the underlying coal seam, stress and microseismic monitoring are adopted to monitor the stress concentration during mining of the underlying coal seam, so as to achieve the purpose of safe recovery of the underlying coal seam.

[0006] When the outer offset overlies the legacy coal pillar for a certain distance, the width of the segmental coal pillar of the underlying coal seam increases, and the coal resource recovery rate is greatly reduced; and when the underlying coal seam is mined, the distance of the outer offset overlying legacy coal pillar is also determined by human experience, and the understanding of the impact hazard between the overlying legacy coal pillar and the underlying coal seam of the inclined coal seam group is unclear. The stress concentration of the overlying legacy segmental coal pillar may not be completely avoided when mining the underlying coal seam.

[0007] At the same time, the basis for arranging pressure relief drilling holes when mining the underlying coal seam is unclear, and the degree of stress concentration that needs to be reduced when mining the underlying coal seam is not clear. In addition, the current stress and microseismic monitoring data have poor accuracy, making it difficult to provide effective early warning for impact disasters.

[0008] Therefore, there is an urgent need to provide an impact hazard assessment method that conforms to engineering practice, so as to accurately determine the impact hazard area and impact hazard degree of underlying coal seam mining, so as to avoid impact disasters. Summary of the invention

[0009] The present invention provides a method for evaluating impact hazard of combined mining of inclined coal seam groups. The method is based on experimental data and theoretical calculations and can truly reflect the stress state and impact hazard during coal seam mining.

[0010] Methods include:

[0011] S101: Determine the target research area of ​​the mining site, obtain standard rock samples of coal in the target area, and use uniaxial compression tests to obtain the uniaxial compressive strength of the standard coal samples at failure. s c , elastic modulus E and Poisson's ratio v , and calculate its post-peak softening modulus l ;

[0012] S102: According to the depth of the overlying coal seam at the mining site H , calculate the vertical compressive stress of the overlying rock strata of the overlying legacy coal pillar s 1, where s 1= cH ;

[0013] S103: Calculate the ultimate strength of the coal pillars separately s max , the distance of the peak value of lateral support pressure from the side of the coal pillar along the inclined direction x m , and the horizontal distance of the overlying residual coal pillar from the side of the coal pillar L = x m cos α ;

[0014] S104: According to the elastic propagation theory, when the disturbance stress wave is transmitted from the vibration source to the coal seam, the lateral support pressure attenuation of the overlying residual coal pillar is obtained;

[0015] S105: Analyze the advance support pressure in front of the stope when mining the underlying coal seam s t ;

[0016] S106: Advanced support pressure based on the disturbance of underlying coal seam mining s t The superposition of the disturbance stress of the overlying legacy coal pillar on the underlying coal seam, the stress after superposition is obtained as s ;

[0017] S107: Obtain the critical stress of rock burst according to the disturbance instability judgment criteria of coal body s cr ;

[0018] S108: Determine the impact risk of mining the underlying coal seam based on the magnitude of the superimposed stress during mining of the underlying coal seam and its relationship with the critical stress of rock burst.

[0019] It should be further explained that in step S101, the triaxial compression test is used to obtain any confining pressure and the confining pressure of the target area, respectively. s 30 , s 31 Triaxial compressive strength of coal under two conditions s 10 , s 11 , and the influence coefficient of confining pressure on compressive strength is calculated by the following method k ;

[0020] k =( s 11 - s 10 ) / ( s 31 - s 30 );

[0021] based on f =arcsin[( k -1) / ( k +1)] and C = s c (1-sin f ) / (2cos f ) to obtain the internal friction angle of the coal sample f and cohesion C .

[0022] It should be further explained that in step S102, the horizontal stress in the coal seam is calculated according to the following formula: s 3;

[0023] ;

[0024] The thickness of the overlying coal seam is defined as M , the support resistance of the coal pillar side is p According to the following formula, the different distances from the side of the coal pillar along the coal seam inclination direction are calculated. x Lateral bearing pressure at s z ;

[0025] .

[0026] It should be further explained that the following formula is used in step S103 to calculate the ultimate strength of the coal pillar: s max :

[0027] ;

[0028] In the formula, or c is the rheological coefficient of coal.

[0029] It should be further explained that step S104 also includes:

[0030] Step 4: Lateral support pressure of the overlying legacy coal pillar s zs The attenuation is calculated as

[0031] s zs = s z · e -ηl ;

[0032] Where: l is the disturbance influence distance of the lateral support pressure inside the overlying legacy coal pillar; or is the stress decay exponent, v is the Poisson's ratio of coal rock.

[0033] It should be further explained that the advance support pressure in step S105 s t The calculation method is:

[0034] ;

[0035] In the formula, x ais the distance from any point in front of the stope to the coal wall; t 0 is the shear strength of the coal body.

[0036] It should be further explained that the superimposed stress in step S106 s The calculation method is:

[0037] s = s zs + s t .

[0038] It should be further explained that the critical stress of rock burst in step S107 is s cr The calculation method is:

[0039] ;

[0040] In the formula, K == λ / E , E is the elastic modulus.

[0041] According to another embodiment of the present application, an evaluation terminal is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of a method for evaluating impact hazard of joint mining of inclined coal seams when executing the program.

[0042] According to another embodiment of the present application, a storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for assessing impact hazard of joint mining of inclined coal seams are implemented.

[0043] It can be seen from the above technical solutions that the present invention has the following advantages:

[0044] The impact hazard assessment method for joint mining of inclined coal seams provided in this application ensures the scientificity and accuracy of the evaluation results by configuring the mechanical properties test of coal samples, such as uniaxial compressive strength, elastic modulus, Poisson's ratio and post-peak softening modulus, combining the calculation of rock stratum compressive stress and the analysis of the ultimate strength and support pressure distribution in the coal pillar, etc. The method is based on experimental data and theoretical calculations, and can truly reflect the stress state and impact hazard during coal seam mining.

[0045] The method of this application not only considers the static pressure effect of the overlying legacy coal pillar on the underlying coal seam (such as vertical compressive stress and lateral support pressure), but also considers the dynamic stress wave propagation and attenuation effect generated by mining disturbance, as well as the superposition of these stresses and the advanced support pressure of the underlying coal seam mining. In this way, a comprehensive analysis can be made to more accurately evaluate the overall stress state and impact risk during the joint mining of inclined coal seams.

[0046] This application provides important early warning information for coal mine safety production by predicting and evaluating the impact risk during the mining process of the underlying coal seam. Coal mine enterprises can take preventive measures in advance according to the evaluation results, such as optimizing mining design, strengthening support strength, implementing monitoring and early warning systems, etc., so as to effectively reduce the probability and degree of harm of rock burst disasters. Moreover, the method provides a scientific impact hazard evaluation method for the joint mining of inclined coal seam groups, which is of great significance for guiding coal mine safety production, improving mining efficiency and economic benefits. Through continuous research and practice, the method can be further improved and optimized, the accuracy and reliability of the evaluation can be improved, and more powerful technical support can be provided for coal mine safety production. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0048] Figure 1 This is a flow chart of the impact hazard assessment method for combined mining of inclined coal seams. DETAILED DESCRIPTION

[0049] In the following description, Figure 1 As shown, the specific steps of the method for evaluating the impact hazard of combined mining of inclined coal seams provided by the present application are given. For the purpose of explanation rather than limitation, specific details such as specific system structures and technologies are proposed to facilitate a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application can also be implemented in other embodiments without these specific details.

[0050] It should be understood that when used in the specification of the method for evaluating impact hazard of joint mining of inclined coal seam groups provided in the present application, the term "include" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or their collections. The terms "include", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0051] It should be understood that when describing in detail the impact hazard assessment method for the joint mining of inclined coal seams, the "one or more" mentioned refers to one, two or more, and the "multiple" mentioned in this application refers to two or more. In the description of this application, unless otherwise specified, " / " means or, for example, A / B can mean A or B. The "and / or" in this article is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0052] The phrases such as "one embodiment" or "some embodiments" described in the present application mean that the specific features, structures or characteristics described in the embodiment are included in one or more embodiments of the present application. Therefore, the phrases such as "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments" etc. that appear in different places in the present application do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways.

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] See also Figure 1 The figure is a flow chart of a method for evaluating impact hazard of combined mining of inclined coal seams in a specific embodiment, the method comprising:

[0055] S101: Determine the target research area of ​​the mining site, obtain standard rock samples of coal in the target area, and use uniaxial compression tests to obtain the uniaxial compressive strength of the standard coal samples at failure. s c , elastic modulus E and Poisson's ratio v , and calculate its post-peak softening modulus l .

[0056] According to the embodiment of the present application, multiple coal samples can be collected from different locations of the target area to ensure the representativeness and uniformity of the samples. This embodiment can be tested using a high-precision uniaxial compression testing machine.

[0057] Optionally, in addition to recording the uniaxial compressive strength s c , elastic modulus E and Poisson's ratiov In addition, the stress-strain curve can also be recorded for subsequent calculation of the post-peak softening modulus λ. Here, the stress-strain curve is used to determine the failure point of the coal sample, and the post-peak softening modulus λ is calculated based on it.

[0058] S102: According to the depth of the overlying coal seam at the mining site H , calculate the vertical compressive stress of the overlying rock strata of the overlying legacy coal pillar s 1, among which, s 1= cH .

[0059] In some embodiments, the average bulk density γ of the overlying rock formation may be obtained through field sampling or geological data.

[0060] S103: Calculate the ultimate strength of the coal pillars separately s max , the distance of the peak value of lateral support pressure from the side of the coal pillar along the inclined direction x m , and the horizontal distance of the overlying residual coal pillar from the side of the coal pillar L = x m cos α .

[0061] In this embodiment, the ultimate strength of the coal pillar is calculated by taking into account the size, shape and surrounding geological conditions of the coal pillar and using empirical formulas or numerical simulation methods. s max For the calculation of lateral support pressure, the peak value of lateral support pressure and its distance from the side of the coal pillar can be calculated based on the mechanical properties of the coal pillar and the ground stress state. x m According to the coal seam inclination angle α, x m Converted to horizontal distance L .

[0062] S104: Based on the elastic propagation theory, when the disturbance stress wave is transmitted from the vibration source to the coal seam, the lateral support pressure attenuation of the overlying legacy coal pillar is obtained.

[0063] In some embodiments, elastic propagation theory can be applied based on lateral support pressure attenuation analysis to analyze the attenuation law of stress waves during propagation according to the propagation characteristics of disturbance stress waves and coal seam medium characteristics. Combined with finite element analysis (FEA) or discrete element analysis (DEM) and other methods, the propagation and attenuation process of stress waves in coal seams can be simulated.

[0064] S105: Analyze the advance support pressure in front of the stope when mining the underlying coal seam s t .

[0065] In some embodiments, stress distribution in front of the mining area: based on mining theory, the distribution law of the advance support pressure σt in front of the mining area when mining the underlying coal seam is analyzed.

[0066] This application considers the influence of mining speed, mining depth, coal seam thickness, roof lithology, etc. on the advance support pressure to analyze the advance support pressure in front of the mining site.

[0067] S106: Advanced support pressure based on the disturbance of underlying coal seam mining s t The superposition of the disturbance stress of the overlying legacy coal pillar on the underlying coal seam, the stress after superposition is obtained as s .

[0068] In this embodiment, when calculating the stress superposition, the advanced support pressure of the underlying coal seam mining can be s t The disturbance stress of the overlying residual coal pillar is superimposed to calculate the total stress σ after superposition. This method considers the spatial position relationship between coal seams during stress superposition to ensure the accuracy of the superposition calculation.

[0069] S107: Obtain the critical stress of rock burst according to the disturbance instability judgment criteria of coal body s cr .

[0070] In the embodiment, the critical stress of rock burst is determined based on the physical and mechanical properties of the coal body and the geological conditions to determine the criterion for coal body disturbance instability. Based on the criterion and the mechanical parameters of the coal sample, the critical stress of rock burst is calculated.

[0071] S108: Determine the impact risk of mining the underlying coal seam based on the magnitude of the superimposed stress during mining of the underlying coal seam and its relationship with the critical stress of rock burst.

[0072] In the embodiment of the present application, according to the superimposed stress σ and the critical stress s cr The impact risk level can be divided according to the comparison results. Corresponding impact ground pressure prevention and control measures can be formulated for different risk levels.

[0073] As one method of this embodiment, real-time stress monitoring and microseismic monitoring are performed during the mining process to verify the theoretical calculation results and adjust the prevention and control measures. The monitoring data are compared and analyzed with the theoretical calculation results to continuously optimize the impact hazard assessment method and prevention and control measures.

[0074] The impact hazard assessment method for joint mining of inclined coal seams provided in the present application takes into account the influence of factors such as the mining depth of the on-site coal seams, the mechanical properties of coal rocks, the thickness of the coal seams, the inclination of the coal seams, and the inter-layer spacing. It can obtain the stress influence range and stress value of the overlying legacy section coal pillar on the underlying coal seam, and accurately judge the stress value and critical value of the impact hazard in different areas of the mining site during the mining of the underlying coal seam. It avoids the traditional experience-based judgment of the influence of the overlying legacy section coal pillar on the mining of the underlying coal seam, and can accurately evaluate the influence range and degree of the overlying legacy section coal pillar on the mining of the underlying coal seam.

[0075] On the basis of the above embodiments, in order to further improve the reliability of the impact hazard assessment method for joint mining of inclined coal seams provided in the above embodiments, an implementable method is hereby provided. In the following embodiments, the impact hazard of underlying mining can be accurately evaluated, and the actual engineering situation on site can be reflected. The calculation method is highly feasible, and the main features of the present invention are rapid determination and real-time display. It can adapt to the assessment of coal seam impact hazard in deep, more complex and changeable surrounding rock stress environments.

[0076] According to another embodiment of the present invention, a method for evaluating impact hazard of combined mining of inclined coal seams includes the following steps:

[0077] S1001: Determine the target research area on site and obtain standard rock samples of coal in the target area.

[0078] This example uses a uniaxial compression test to obtain the uniaxial compressive strength of the standard coal sample at failure. s c , elastic modulus E and Poisson's ratio v , and calculate its post-peak softening modulus l .

[0079] Optionally, triaxial compression test is used to obtain any confining pressure and the confining pressure of the target area, respectively. s 30 , s 31 Triaxial compressive strength of coal under two conditions s 10 , s 11 , and calculate the influence coefficient of confining pressure on compressive strength k , k =( s 11 - s 10 ) / ( s 31 - s 30 ), and thus calculate the internal friction angle of the coal sample f and cohesionC , f =arcsin[( k -1) / ( k +1)], C = s c (1-sin f ) / (2cos f ).

[0080] S1002: According to the depth of the overlying coal seam on site H , calculate the vertical compressive stress of the overlying rock strata of the overlying legacy coal pillar s 1, s 1= cH .

[0081] According to formula (1), Poisson's ratio υ and vertical stress of overburden are calculated. s 1 Obtaining horizontal stress in coal seam s 3.

[0082] (1)

[0083] Let the thickness of the overlying coal seam be M , the support resistance of the coal pillar side is p According to formula (2), the different distances from the side of the coal pillar along the coal seam inclination direction can be calculated. x Lateral bearing pressure at s z .

[0084] (2)

[0085] S1003: Ultimate strength within the coal pillar s max It can be calculated using formula (3).

[0086] (3)

[0087] In the formula, or c is the rheological coefficient of coal.

[0088] In this application, s z = s max , the distance of the peak value of the lateral support pressure from the side of the coal pillar along the inclined direction can be calculated x m , then the horizontal distance between the overlying residual coal pillar and the side of the coal pillar is L = x m cos α ,in αCoal seam inclination.

[0089] S1004: According to the elastic propagation theory, when the disturbance stress wave is transmitted from the vibration source to the coal seam, the lateral support pressure of the overlying residual coal pillar s zs Decays to,

[0090] s zs = s z · e -ηl (4)

[0091] Where: l is the disturbance influence distance of the lateral support pressure inside the overlying legacy coal pillar, m; or is the stress attenuation index, referring to the stress wave attenuation index of rock or =2- v / (1- v ), v is the Poisson's ratio of coal rock.

[0092] when s zs = 0, the internal stress of the overlying legacy coal pillar will have no effect on the mining of the underlying coal seam. Based on this and formula (2), the influence range of the overlying legacy coal pillar on the underlying coal seam along the coal seam inclination direction can be calculated, and the stress value of any point within the influence range of the underlying coal seam transmitted by the lateral support pressure of the overlying legacy coal pillar can be calculated. s zs .

[0093] S1005: When the underlying coal seam is mined, due to the disturbance caused by the mining of the underlying coal seam, there is an advanced support pressure in front of the mining area s t , which is calculated as:

[0094] (5)

[0095] In the formula, x a is the distance from any point in front of the stope to the coal wall; t 0 is the shear strength of the coal body, and the calculation method is t 0=C+ l tan f .

[0096] S1006: Advance support pressure in the underlying coal seam mining disturbance s t The superposition of the disturbance stress of the overlying legacy coal pillar on the underlying coal seam increases the stress in the leading coal body of the underlying coal seam. The superimposed stress is s ,but

[0097] s = s zs + s t (6)

[0098] S1007: Affected by the stress disturbance of the overlying legacy coal pillars, the mining of the underlying coal seam is very likely to cause impact hazards due to the action of the overlying legacy coal pillars, especially when the underlying coal seam tunnels are arranged within the stress disturbance influence range of the overlying legacy coal pillars, the impact risk is more likely to occur.

[0099] In this embodiment, according to the disturbance instability judgment criterion of coal body, the critical stress for the occurrence of this type of rock burst can be calculated: s cr for:

[0100] (7)

[0101] In the formula, K == λ / E , E is the elastic modulus.

[0102] when s ≥ s cr When the coal body in front of the underlying coal seam mining area is impacted.

[0103] S1008: Based on the magnitude of superimposed stress during the mining of the underlying coal seam and its relationship with the critical stress of rock burst, the rock burst risk of the underlying coal seam can be determined, thereby providing reliable basic data for analyzing the rock burst hazard on site.

[0104] As an implementation method of the present application, the impact hazard assessment method for joint mining of inclined coal seam groups can be applied to an assessment terminal, which can be a mobile terminal (MT), a mobile station (MS), a mobile unit (MU), a wireless unit, a remote unit, a user agent, a mobile client, etc. For example, the assessment terminal can be a mobile phone, a smart screen device, a tablet computer, a laptop computer, an ultra-mobile personal computer (UMPC), a personal digital assistant (PDA), a laptop computer, etc., and the present application embodiment does not limit this.

[0105] The evaluation terminal has a built-in program for the impact hazard evaluation method for the joint mining of inclined coal seams, and automatically calculates the parameters of each coal body, the range of disturbance influence of the overlying legacy coal pillar on the underlying coal seam, the superimposed stress value and other conditions. The computer quickly displays the magnitude of the superimposed stress during the mining of the underlying coal seam and its relationship with the critical stress of rock burst, and the impact risk of mining the underlying coal seam can be determined based on it, thereby providing reliable basic data for analyzing the impact hazard of the rock mass on site.

[0106] In some embodiments of the present application, the evaluation terminal may include a processor, an external memory interface, a memory, a USB interface, a wireless communication module, an audio module, a mouse and keyboard, a display screen, etc.

[0107] It is to be understood that the structure illustrated in the embodiment of the present application does not constitute a specific limitation on the evaluation terminal. In other embodiments of the present application, the evaluation terminal may include more or fewer components than shown in the figure, or combine certain components, or split certain components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0108] The processor may include one or more processing units, for example, the processor may include a central processing unit (CPU), an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), etc. Among them, different processing units may be independent devices or integrated into one or more processors.

[0109] The processor can be the nerve center and command center of the evaluation terminal. The controller can generate operation control signals according to the instruction operation code and timing signal to complete the control of fetching and executing instructions.

[0110] The method for assessing impact hazard of joint mining of inclined coal seams involved in the present application is a method that combines the units and algorithm steps of each example described in the embodiments disclosed herein, and can be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0111] In the storage medium involved in this application, a program product capable of implementing the above method of this specification is stored. In some possible implementations, various aspects of the present disclosure can also be implemented in the form of a program product, which includes a program code. When the program product is run on a terminal device, the program code is used to enable the terminal device to execute the steps according to various exemplary implementations of the present disclosure described in the above "Exemplary Method" section of this specification.

[0112] The storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0113] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for evaluating impact hazard of joint mining of inclined coal seams, characterized in that: Methods include: S101: Determine the target research area of ​​the mining site, obtain standard rock samples of coal in the target area, and use uniaxial compression tests to obtain the uniaxial compressive strength of the standard coal samples at failure. σ c , elastic modulus E and Poisson's ratio v , and calculate its post-peak softening modulus λ ; S102: According to the depth of the overlying coal seam at the mining site H , calculate the vertical compressive stress of the overlying rock strata of the overlying legacy coal pillar σ 1, where σ 1= γH ; γ is the average bulk density of the overlying rock layer; The horizontal stress in the coal seam is calculated according to the following formula σ 3; ； The thickness of the overlying coal seam is defined as M , the support resistance of the coal pillar side is p According to the following formula, the different distances from the side of the coal pillar along the coal seam inclination direction are calculated. x Lateral bearing pressure at σ z ; S103: Calculate the ultimate strength of the coal pillars separately σ max , the distance of the peak value of lateral support pressure from the side of the coal pillar along the inclined direction x m , and the horizontal distance of the overlying residual coal pillar from the side of the coal pillar L = x m cos α ; α is the coal seam inclination angle; S104: According to the elastic propagation theory, when the disturbance stress wave is transmitted from the vibration source to the coal seam, the lateral support pressure attenuation of the overlying residual coal pillar is obtained; Attenuation of lateral support pressure of overlying legacy coal pillar σ zs The calculation method is σ zs = σ z · e -ηl ； Where: l is the disturbance influence distance of the lateral support pressure inside the overlying legacy coal pillar; η is the stress decay exponent, v is the Poisson's ratio of coal rock; S105: Analyze the advance support pressure in front of the stope when mining the underlying coal seam σ t ; S106: Advanced support pressure based on the disturbance of underlying coal seam mining σ t and the disturbance stress of the overlying legacy coal pillar on the underlying coal seam σ zs Superposition effect, obtain the stress after superposition σ ; S107: Obtain the critical stress of rock burst according to the disturbance instability judgment criteria of coal body σ cr ; S108: Determine the impact risk of mining the underlying coal seam based on the magnitude of the superimposed stress during mining of the underlying coal seam and its relationship with the critical stress of rock burst.

2. The method for evaluating impact risk of combined mining of inclined coal seams according to claim 1 is characterized in that: In step S101, a triaxial compression test is used to obtain any confining pressure and the confining pressure of the target area. σ 30 , σ 31 Triaxial compressive strength of coal under two conditions σ 10 , σ 11 , and the influence coefficient of confining pressure on compressive strength is calculated by the following method k ; k =( σ 11 - σ 10 ) / ( σ 31 - σ 30 )； based on φ =arcsin[( k -1) / ( k +1)] and C = σ c (1-sin φ ) / (2cos φ ) to obtain the internal friction angle of the coal sample φ and cohesion C .

3. The method for evaluating impact risk of combined mining of inclined coal seams according to claim 1 is characterized in that: In step S103, the ultimate strength in the coal pillar is calculated using the following formula: σ max : ； In the formula, η c is the rheological coefficient of coal.

4. The method for evaluating impact risk of combined mining of inclined coal seams according to claim 1 is characterized in that: The advance support pressure in step S105 σ t The calculation method is: ； In the formula, x a is the distance from any point in front of the stope to the coal wall; τ 0 is the shear strength of the coal body.

5. The method for evaluating impact risk of combined mining of inclined coal seams according to claim 4 is characterized in that: The stress after superposition in step S106 σ The calculation method is: σ = σ zs + σ t 。 6. The method for evaluating impact risk of combined mining of inclined coal seams according to claim 1 is characterized in that: Critical stress of rock burst in step S107 σ cr The calculation method is: ； In the formula, K == λ / E , E is the elastic modulus.

7. An evaluation terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method for evaluating impact hazard of joint mining of inclined coal seams as described in any one of claims 1 to 6 are implemented.

8. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for assessing impact hazard of joint mining of inclined coal seams as described in any one of claims 1 to 6 are implemented.

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