Negative coal pillar impact risk identification and prevention method under dynamic load disturbance

Abstract

The invention relates to the technical field of coal mine safety, and provides a negative coal pillar impact risk identification and prevention method under dynamic load disturbance. The method comprises the following steps: firstly, traversing micro-seismic monitoring data of stopes around a negative coal pillar roadway and immediate roof and immediate bottom areas under historical dynamic loads, dividing dynamic load space types, and calculating a dynamic load energy coefficient and radial displacement corresponding to each historical dynamic load; and then, sorting the dynamic load energy coefficients and radial displacements corresponding to all historical dynamic loads, and carrying out impact risk identification on the negative coal pillar roadway according to the minimum dynamic load energy coefficient and the maximum radial displacement based on a sorting result. Therefore, the corresponding dynamic load energy coefficient and the radial displacement are respectively calculated according to the dynamic load space type, the division of the impact risk of the negative coal pillar roadway is realized, the impact risk of the negative coal pillar roadway under dynamic load disturbance is quickly, accurately and scientifically judged, a targeted pressure relief measure is provided, theoretical guidance is provided for field engineering practice, and the method is suitable for popularization and application. And safe construction of the negative coal pillar roadway is guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of coal mine safety, and in particular to a method for identifying and preventing the hazard of negative coal pillar impact under dynamic load disturbance. Background Art

[0002] Deep mining has become a major trend in the coal mining industry. With the increase in mining depth, the frequency and energy of rock burst are also increasing, which has a huge impact on the safe and efficient mining of deep resources. During the mining process, the two return mining tunnels of the longwall working face are arranged along the roof and floor respectively, and the lower end of the working face is arc-shaped. The staggered or overlapping arrangement of the two tunnels will produce negative coal pillars. The negative coal pillar tunnel is located below the edge of the goaf, which can avoid high stress and reduce the risk of rock burst in the tunnel. In order to solve the problem of frequent rock burst and serious damage, the existing "negative coal pillar" to prevent rock burst disasters along the goaf has been widely used in rock burst mines. Summary of the invention

[0003] The purpose of this application is to provide a method for identifying and preventing the danger of negative coal pillar impact under dynamic load disturbance, so as to solve or alleviate the problems existing in the above-mentioned prior art.

[0004] In order to achieve the above objectives, this application provides the following technical solutions:

[0005] The present application provides a method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance, which is used for identifying and preventing the impact hazard of negative coal pillar tunnels. The method includes: step S101, traversing the microseismic monitoring data of the mining area and the direct top and bottom areas around the negative coal pillar tunnel under historical dynamic loads to divide the dynamic load space type, and calculating the dynamic load energy coefficient and radial displacement corresponding to each historical dynamic load; step S102, sorting the dynamic load energy coefficients and radial displacements corresponding to all the historical dynamic loads, and based on the sorting results, identifying the impact hazard of the negative coal pillar tunnel according to the minimum dynamic load energy coefficient and the maximum radial displacement.

[0006] Preferably, in step S101, according to the formula:

[0007]

[0008] Determine the dynamic load energy coefficient under the i-th historical dynamic load and the radial displacement u i ;

[0009] Where ρ2 is the density of the broken coal seam corresponding to the negative coal pillar roadway, U i is the dynamic load source energy of the i-th historical dynamic load, i∈I, I is the total number of the historical dynamic loads; i and I are both positive integers;

[0010] k m is the energy attenuation index of the dynamic load source energy in the medium; when m=1, k m =k 1 , k 1 is the energy attenuation index of the dynamic load source energy in the roof rock layer or broken coal layer. When m=2, k m =k 2 , k 2 is the energy attenuation index of the dynamic load source energy in the bottom rock layer;

[0011] p u is the support resistance of the U-shaped shed used to support the negative coal pillar roadway, b is the width of the negative coal pillar roadway, u is o is the shed distance of the U-shaped shed, p z is the support resistance of the hydraulic support adapted to the U-shaped shed, u z is the distance between two adjacent hydraulic supports along the direction of the negative coal pillar roadway; s is the average displacement of the negative coal pillar roadway,

[0012] is the internal friction angle of the surrounding rock outside the negative coal pillar roadway, G is the shear modulus of the surrounding rock, p0 is the original rock stress corresponding to the negative coal pillar roadway, C is the original rock cohesion corresponding to the negative coal pillar roadway, It is the peak dynamic load when the negative coal pillar roadway is subjected to the i-th historical dynamic load.

[0013] Preferably, in response to the dynamic load space being a roof type or a coal seam type, according to the formula:

[0014]

[0015] Determine the peak dynamic load of the negative coal pillar tunnel when it is subjected to the i-th historical dynamic load In the formula, A i is the amplitude of the incident wave of the i-th historical dynamic load; k 1 is the energy attenuation index of the dynamic load source energy in the roof rock layer or broken coal layer;

[0016] When j = 1, ρ j =ρ1,E aj =E a1 , ρ1 is the density of the roof rock layer, E a1 is the elastic modulus of the roof rock layer;

[0017] When j = 2, ρ j =ρ2,E aj =E a2 , p2 is the density of the broken coal seam, E a2is the elastic modulus of the broken coal seam.

[0018] Preferably, in response to the dynamic load space being a bottom plate type, according to the formula:

[0019]

[0020] Determine the peak dynamic load of the negative coal pillar tunnel when it is subjected to the i-th historical dynamic load In the formula, A i is the amplitude of the incident wave of the i-th historical dynamic load; k 2 is the energy attenuation index of the dynamic load source energy in the bottom rock layer; ρ3 is the density of the bottom rock layer, E a3 is the elastic modulus of the bottom rock formation.

[0021] Preferably, in response to the dynamic load space being a roof type or a coal seam type, according to the formula:

[0022] k 1 =β1r1+β2r2

[0023] Determine the energy attenuation index k of the dynamic load source energy in the roof rock layer or the broken coal layer 1 ; Wherein, β1 is the attenuation coefficient of the dynamic load source energy in the roof rock layer, β2 is the attenuation coefficient of the dynamic load source energy in the broken coal seam, r1 is the length of the roof rock layer or coal seam section on the line connecting the source point of the historical dynamic load and the negative coal pillar roadway, and r2 is the length of the broken coal seam section on the line connecting the source point and the negative coal pillar roadway;

[0024] In response to the dynamic load space being a bottom plate type, according to the formula:

[0025] k 2 =β3r3

[0026] Determine the energy attenuation index k of the dynamic load source energy in the bottom rock layer 2 Wherein, β3 is the attenuation coefficient of the dynamic load source energy in the bottom rock layer, and r3 is the distance between the source point of the historical dynamic load and the negative coal pillar roadway.

[0027] Preferably, according to the formula:

[0028]

[0029] Calculate the attenuation coefficient β of the dynamic load source energy in the medium j ;

[0030] Among them, when j = 1, β j =β1,ρ j =ρ1,E aj =Ea1 , β1 is the attenuation coefficient of the dynamic load source energy in the top rock layer; ρ1 is the density of the top rock layer, E a1 is the elastic modulus of the roof rock layer;

[0031] When j = 2, β j =β2,ρ j =ρ2,E aj =E a2 , β2 is the attenuation coefficient of the dynamic load source energy in the broken coal seam; ρ2 is the density of the broken coal seam, E a2 is the elastic modulus of the broken coal seam;

[0032] When j = 3, β j =β3,ρ j =ρ3,E aj =E a3 , β3 is the attenuation coefficient of the dynamic load source energy in the bottom rock layer; ρ3 is the density of the bottom rock layer, E a3 is the elastic modulus of the bottom rock layer;

[0033] Where f is the frequency of the vibration wave of the dynamic source energy, E v is the stiffness of the structural weak plane of the original rock, η v is the viscosity coefficient of the weak surface of the structure.

[0034] Preferably, in step S102, in response to Or, max >200, the negative coal pillar roadway has a strong impact risk, then the width of the pressure relief protection zone of the negative coal pillar roadway is increased and the source energy of the negative coal pillar roadway is reduced; wherein, is the minimum dynamic load energy coefficient, u max is the maximum radial displacement.

[0035] Preferably, according to the formula:

[0036]

[0037] Determine the width of the pressure relief protection zone of the negative coal pillar tunnel under the influence of the historical dynamic load for the i-th time Where x is the distance from the dynamic load to the negative coal pillar tunnel; ρ2 is the density of the broken coal seam, p u is the support resistance of the U-shaped shed used to support the negative coal pillar roadway, b is the width of the negative coal pillar roadway, u is o is the shed distance of the U-shaped shed, p z is the support resistance of the hydraulic support adapted to the U-shaped shed, u zis the distance between two adjacent hydraulic supports along the direction of the negative coal pillar roadway; s is the average displacement of the negative coal pillar roadway,

[0038] U i is the dynamic load source energy of the i-th historical dynamic load, i∈I, I is the total number of historical dynamic loads; i and I are both positive integers, β1 is the attenuation coefficient of the shock wave energy in the roof rock layer or coal seam, and β2 is the attenuation coefficient of the shock wave energy in the broken coal seam.

[0039] Beneficial effects:

[0040] The method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance provided in the embodiment of the present application is used to identify and prevent the impact hazard of negative coal pillar tunnels. First, the microseismic monitoring data of the mining area and the direct top and direct bottom areas around the negative coal pillar tunnels under historical dynamic loads are traversed to divide the dynamic load space type, and the dynamic load energy coefficient and radial displacement corresponding to each historical dynamic load are calculated; then, the dynamic load energy coefficients and radial displacements corresponding to all historical dynamic loads are sorted, and the impact hazard of the negative coal pillar tunnel is identified based on the smallest dynamic load energy coefficient and the largest radial displacement based on the sorting results. Thus, the corresponding dynamic load energy coefficient and radial displacement are calculated according to the dynamic load space type, the impact hazard of the negative coal pillar tunnel is divided, the impact hazard of the negative coal pillar tunnel under dynamic load disturbance is quickly, accurately and scientifically determined, and targeted pressure relief measures are proposed, which provides theoretical guidance for the actual on-site engineering and ensures the safe construction of the negative coal pillar tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0042] in:

[0043] Figure 1 A schematic flow chart of a method for identifying and preventing the danger of negative coal pillar impact under dynamic load disturbance provided according to some embodiments of the present application;

[0044] Figure 2 A logical schematic diagram of a method for identifying and preventing the danger of negative coal pillar impact under dynamic load disturbance provided in accordance with some embodiments of the present application;

[0045] Figure 3 Schematic diagram of energy transfer of shock waves in different types of dynamic loading spaces according to some embodiments of the present application. DETAILED DESCRIPTION

[0046] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. Each example is provided by way of explanation of the present application and does not limit the present application. In fact, it will be clear to those skilled in the art that modifications and variations may be made in the present application without departing from the scope or spirit of the present application. For example, a feature shown or described as a part of an embodiment may be used in another embodiment to produce yet another embodiment. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the embodiments of the present invention should belong to the scope of protection of the embodiments of the present invention.

[0047] In the existing applications of preventing and controlling rock burst disasters in goaf-side tunnels through negative coal pillars, the main focus is on the "negative coal pillar" layout method, which can effectively avoid the peak value of the supporting static load and thus achieve the rock burst prevention effect. However, there is a lack of analysis and research on the rock burst of negative coal pillar tunnels induced by dynamic loads, making it difficult to accurately prevent and control this type of rock burst.

[0048] Based on this, the embodiment of the present application proposes a method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance, which calculates the corresponding dynamic load energy coefficient and radial displacement according to the dynamic load space type, realizes the division of the impact hazard of negative coal pillar tunnels, and then carries out targeted anti-impact on negative coal pillar tunnels according to the division results, ensures the safety of excavation, protects the safety of underground personnel, improves production efficiency, and fills the gap in the impact ground pressure mechanism of traditional negative coal pillar tunnels. Figures 1 to 3 As shown, the method for identifying and preventing impact danger in a negative coal pillar roadway includes:

[0049] Step S101, traverse the microseismic monitoring data of the mining area and the immediate roof and immediate bottom areas around the negative coal pillar roadway under historical dynamic loads to divide the dynamic load space type, and calculate the dynamic load energy coefficient and radial displacement corresponding to each historical dynamic load.

[0050] In this application, microseismic monitoring data (historical data) is obtained through the microseismic monitoring system of the mining area (KJ551 microseismic monitoring system or SOS microseismic monitoring system), and the dynamic load space type of the mining area and the direct top area and the direct bottom area of ​​the negative coal pillar tunnel is divided according to the microseismic monitoring data (source coordinates, source energy) of the mining area and the direct top area and the direct bottom area of ​​the negative coal pillar tunnel under the historical dynamic load (large energy microseismic events). Then, according to the spatial relationship between the source coordinates, the source energy and the tunnel, the tunnel dynamic load space is divided into roof type, coal seam type and bottom plate type. Then, according to the different dynamic load space types, the corresponding dynamic load energy coefficient and radial displacement (displacement of the tunnel induced by mine earthquake) under each historical dynamic load are calculated. Specifically, according to the formula:

[0051]

[0052] Determine the dynamic load energy coefficient under the i-th historical dynamic load and the radial displacement u i .

[0053] Where ρ2 is the density of the broken coal seam corresponding to the negative coal pillar roadway, U i is the dynamic load source energy of the i-th historical dynamic load, i∈I, I is the total number of historical dynamic loads; i and I are both positive integers; k m is the energy attenuation index of the dynamic load source energy in the medium; when m=1, k m =k 1 , k 1 is the energy attenuation index of the dynamic load source energy in the roof rock layer or broken coal seam. When m=2, k m =k 2 , k 2 is the energy attenuation index of the dynamic load source energy in the bottom rock layer; p u is the support resistance of the U-shaped shed used to support the negative coal pillar roadway, b is the width of the negative coal pillar roadway, u is o is the shed distance of the U-shaped shed, p z is the support resistance of the hydraulic support adapted to the U-shaped shed, u z is the distance between two adjacent hydraulic supports along the direction of the negative coal pillar roadway; s is the average displacement of the negative coal pillar roadway, is the internal friction angle of the surrounding rock outside the negative coal pillar roadway, G is the shear modulus of the surrounding rock, p0 is the original rock stress corresponding to the negative coal pillar roadway, C is the original rock cohesion corresponding to the negative coal pillar roadway, It is the peak dynamic load when the negative coal pillar roadway is subjected to the i-th historical dynamic load.

[0054] Here, it should be noted that the U-shaped shed and the matching hydraulic support together constitute the support assembly of the negative coal pillar roadway, which is used to support the negative coal pillar roadway to keep the roadway unobstructed and the surrounding rock stable, thereby achieving the purpose of safe production.

[0055] In the roof type dynamic load space type, the propagation path of the shock wave is the earthquake source (roof)-roof rock layer-broken coal seam-negative coal pillar tunnel; in the coal seam type dynamic load space type, the propagation path of the shock wave is the coal seam earthquake source-broken coal seam-negative coal pillar tunnel. When the dynamic load space is roof type or coal seam type, according to the formula:

[0056]

[0057] Determine the peak dynamic load of the negative coal pillar tunnel when it is subjected to the i-th historical dynamic load In the formula, A i is the amplitude of the incident wave of the ith historical dynamic load; k 1 is the energy attenuation index of the dynamic load source energy in the roof rock layer or broken coal seam; where, when j=1, ρ j =ρ1,Eaj =E a1 , ρ1 is the density of the roof rock layer, E a1 is the elastic modulus of the roof rock; when j = 2, ρ j =ρ2,E aj =E a2 , ρ2 is the density of the broken coal seam, E a2 is the elastic modulus of the broken coal seam.

[0058] At the same time, according to the formula:

[0059] k 1 =β1r1+β2r2

[0060] Determine the energy attenuation index k of the dynamic load source energy in the roof rock layer or broken coal layer 1 ; In the formula, β1 is the attenuation coefficient of the dynamic load source energy in the roof rock layer, β2 is the attenuation coefficient of the dynamic load source energy in the broken coal seam, r1 is the length of the roof rock layer or coal seam section on the line connecting the source point of the historical dynamic load and the negative coal pillar roadway, and r2 is the length of the broken coal seam section on the line connecting the source point and the negative coal pillar roadway.

[0061] In the floor type dynamic load space type, the propagation path of the shock wave is floor source-floor rock layer-negative coal pillar roadway. At this time, according to the formula:

[0062]

[0063] Determine the peak dynamic load of the negative coal pillar tunnel when it is subjected to the i-th historical dynamic load In the formula, A i is the amplitude of the incident wave of the ith historical dynamic load; k 2 is the energy attenuation index of the dynamic load source energy in the bottom rock layer; ρ3 is the density of the bottom rock layer, E a3 is the elastic modulus of the bottom rock.

[0064] At the same time, according to the formula:

[0065] k 2 =β3r3

[0066] Determine the energy attenuation index k of the dynamic load source energy in the bottom rock layer 2 Where β3 is the attenuation coefficient of the dynamic load source energy in the bottom rock layer, and r3 is the distance between the source point of the historical dynamic load and the negative coal pillar roadway.

[0067] In different types of dynamic load spaces, the transmission paths of shock waves are different, and the energy attenuation of dynamic load source energy along different propagation paths is also different.

[0068]

[0069] Calculate the attenuation coefficient β of the dynamic load source energy in the medium j ; where f is the frequency of the vibration wave of the dynamic source energy, E v is the stiffness of the structural weak plane of the original rock, η v is the viscosity coefficient of the weak surface of the structure.

[0070] Among them, when j = 1, β j =β1,ρ j =ρ1,E aj =E a1 , β1 is the attenuation coefficient of the dynamic load source energy in the roof rock layer; ρ1 is the density of the roof rock layer, E a1 is the elastic modulus of the roof rock; when j = 2, β j =β2,ρ j =ρ2,E aj =E a2 , β2 is the attenuation coefficient of the dynamic load source energy in the broken coal seam; ρ2 is the density of the broken coal seam, E a2 is the elastic modulus of the broken coal seam; when j=3, β j =β3,ρ j =ρ3,E aj =E a3 , β3 is the attenuation coefficient of the dynamic load source energy in the bottom rock layer; ρ3 is the density of the bottom rock layer, E a3 is the elastic modulus of the bottom rock.

[0071] Step S102: sort the dynamic load energy coefficients and radial displacements corresponding to all historical dynamic loads, and based on the sorting results, identify the impact hazard of the negative coal pillar roadway according to the minimum dynamic load energy coefficient and the maximum radial displacement.

[0072] After obtaining the dynamic load energy coefficient and radial displacement under each historical dynamic load, the minimum dynamic load energy coefficient is found by sorting I (I is a positive integer) dynamic load energy coefficients and radial displacements respectively. and the maximum radial displacement u max .when Or, nax >200, the negative coal pillar roadway has a strong impact hazard; and u max When ≤200, the negative coal pillar roadway has a weak impact hazard.

[0073] When it is determined that the negative coal pillar tunnel has a strong impact hazard, the safety of tunnel excavation can be ensured by increasing the width of the pressure relief protection zone of the negative coal pillar tunnel, reducing the source energy and enhancing the tunnel support strength. Among them, according to the formula:

[0074]

[0075] Determine the width of the pressure relief protection zone of the negative coal pillar roadway under the influence of the i-th historical dynamic load The calculated I pressure relief protection zone widths are traversed to obtain the maximum pressure relief protection zone width, which is used as the construction width to reduce the impact hazard of negative coal pillar tunnels.

[0076] Where x is the distance from the dynamic load to the negative coal pillar tunnel; ρ2 is the density of the broken coal seam, p u is the support resistance of the U-shaped shed used to support the negative coal pillar roadway, b is the width of the negative coal pillar roadway, u is o is the shed distance of the U-shaped shed, p z is the support resistance of the hydraulic support adapted to the U-shaped shed, u z is the distance between two adjacent hydraulic supports along the direction of the negative coal pillar roadway; s is the average displacement of the negative coal pillar roadway, U i is the dynamic load source energy of the i-th historical dynamic load, i∈I, I is the total number of historical dynamic loads; i and I are both positive integers, β1 is the attenuation coefficient of the shock wave energy in the roof rock layer or coal seam, and β2 is the attenuation coefficient of the shock wave energy in the broken coal seam.

[0077] The width of the pressure relief zone on the production side of the tunnel is increased to the theoretically calculated pressure relief protection zone width through measures such as large-diameter pressure relief drilling. It is recommended to increase it to 1.2 times to leave a certain margin of error. The specific measures to reduce the source energy are roof pre-splitting blasting; the measures to enhance the strength of tunnel support mainly include: reducing the distance between U-shaped sheds and hydraulic support rows, adding U-shaped shed frame anti-collapse structure, and selecting U-shaped sheds and hydraulic supports with better support effects. When it is determined that the negative coal pillar tunnel has a certain impact risk, a support combination consisting of hydraulic supports and U-shaped sheds can be used for joint support.

[0078] Therefore, the corresponding dynamic load energy coefficient and radial displacement are calculated according to the dynamic load space type, the impact hazard of the negative coal pillar roadway is divided, the impact hazard of the negative coal pillar roadway under dynamic load disturbance is determined quickly, accurately and scientifically, and targeted pressure relief measures are proposed, which provides theoretical guidance for the actual on-site engineering and ensures the safe construction of the negative coal pillar roadway.

[0079] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0080] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0081] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0082] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0083] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0084] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance, characterized in that: Used for identifying and preventing impact hazards in negative coal pillar tunnels, the method comprises: Step S101, traversing the microseismic monitoring data of the mining area and the immediate top and bottom areas around the negative coal pillar roadway under historical dynamic loads to divide the dynamic load space type, and calculating the dynamic load energy coefficient and radial displacement corresponding to each historical dynamic load; Step S102: sorting the dynamic load energy coefficients and radial displacements corresponding to all the historical dynamic loads, and based on the sorting results, identifying the impact hazard of the negative coal pillar roadway according to the minimum dynamic load energy coefficient and the maximum radial displacement.

2. The method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance according to claim 1 is characterized in that: In step S101, According to the formula: Determine the dynamic load energy coefficient under the i-th historical dynamic load and the radial displacement u i ; Where ρ2 is the density of the broken coal seam corresponding to the negative coal pillar roadway, U i is the dynamic load source energy of the i-th historical dynamic load, i∈I, I is the total number of historical dynamic loads; i and I are both positive integers; k m is the energy attenuation index of the dynamic load source energy in the medium; when m=1, k m =k 1 , k 1 is the energy attenuation index of the dynamic load source energy in the roof rock layer or broken coal layer. When m=2, k m =k 2 , k 2 is the energy attenuation index of the dynamic load source energy in the bottom rock layer; p u is the support resistance of the U-shaped shed used to support the negative coal pillar roadway, b is the width of the negative coal pillar roadway, u is o is the shed distance of the U-shaped shed, p z is the support resistance of the hydraulic support adapted to the U-shaped shed, u z is the distance between two adjacent hydraulic supports along the direction of the negative coal pillar roadway; s is the average displacement of the negative coal pillar roadway, is the internal friction angle of the surrounding rock outside the negative coal pillar roadway, G is the shear modulus of the surrounding rock, p0 is the original rock stress corresponding to the negative coal pillar roadway, C is the original rock cohesion corresponding to the negative coal pillar roadway, It is the peak dynamic load when the negative coal pillar roadway is subjected to the i-th historical dynamic load.

3. The method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance according to claim 2 is characterized in that: In response to the dynamic load space being a roof type or a coal seam type, according to the formula: Determine the peak dynamic load of the negative coal pillar tunnel when it is subjected to the i-th historical dynamic load In the formula, A i is the amplitude of the incident wave of the i-th historical dynamic load; k 1 is the energy attenuation index of the dynamic load source energy in the roof rock layer or broken coal layer; When j = 1, ρ j =ρ1,E aj =E a1 , ρ1 is the density of the roof rock layer, E a1 is the elastic modulus of the roof rock layer; When j = 2, ρ j =ρ2,E aj =E a2 , ρ2 is the density of the broken coal seam, E a2 is the elastic modulus of the broken coal seam.

4. The method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance according to claim 2 is characterized in that: In response to the dynamic load space being a bottom plate type, according to the formula: Determine the peak dynamic load of the negative coal pillar tunnel when it is subjected to the i-th historical dynamic load In the formula, A i is the amplitude of the incident wave of the i-th historical dynamic load; k 2 is the energy attenuation index of the dynamic load source energy in the bottom rock layer; ρ3 is the density of the bottom rock layer, E a3 is the elastic modulus of the bottom rock formation.

5. The method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance according to claim 2 is characterized in that: In response to the dynamic load space being a roof type or a coal seam type, according to the formula: k 1 ＝β1r1+β2r2 Determine the energy attenuation index k of the dynamic load source energy in the roof rock layer or the broken coal layer 1 ; Wherein, β1 is the attenuation coefficient of the dynamic load source energy in the roof rock layer, β2 is the attenuation coefficient of the dynamic load source energy in the broken coal seam, r1 is the length of the roof rock layer or coal seam section on the line connecting the source point of the historical dynamic load and the negative coal pillar roadway, and r2 is the length of the broken coal seam section on the line connecting the source point and the negative coal pillar roadway; In response to the dynamic load space being a bottom plate type, according to the formula: k 2 ＝β3r3 Determine the energy attenuation index k of the dynamic load source energy in the bottom rock layer 2 Wherein, β3 is the attenuation coefficient of the dynamic load source energy in the bottom rock layer, and r3 is the distance between the source point of the historical dynamic load and the negative coal pillar roadway.

6. The method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance according to claim 5 is characterized in that: According to the formula: Calculate the attenuation coefficient β of the dynamic load source energy in the medium j ; Among them, when j = 1, β j =β1,ρ j =ρ1,E aj =E a1 , β1 is the attenuation coefficient of the dynamic load source energy in the top rock layer; ρ1 is the density of the top rock layer, E a1 is the elastic modulus of the roof rock layer; When j = 2, β j =β2,ρ j =ρ2,E aj =E a2 , β2 is the attenuation coefficient of the dynamic load source energy in the broken coal seam; ρ2 is the density of the broken coal seam, E a2 is the elastic modulus of the broken coal seam; When j = 3, β j =β3,ρ j =ρ3,E aj =E a3 , β3 is the attenuation coefficient of the dynamic load source energy in the bottom rock layer; ρ3 is the density of the bottom rock layer, E a3 is the elastic modulus of the bottom rock layer; Where f is the frequency of the vibration wave of the dynamic source energy, E v is the stiffness of the structural weak plane of the original rock, η v is the viscosity coefficient of the weak surface of the structure.

7. The method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance according to claim 1 is characterized in that: In step S102, In response to Or, max >200, the negative coal pillar roadway has a strong impact risk, then the width of the pressure relief protection zone of the negative coal pillar roadway is increased and the source energy of the negative coal pillar roadway is reduced; wherein, is the minimum dynamic load energy coefficient, u max is the maximum radial displacement.

8. The method for identifying and preventing the impact hazard of negative coal pillars under dynamic load disturbance according to claim 7 is characterized in that: According to the formula: Determine the width of the pressure relief protection zone of the negative coal pillar tunnel under the influence of the historical dynamic load for the i-th time Where x is the distance from the dynamic load to the negative coal pillar tunnel; ρ2 is the density of the broken coal seam, p u is the support resistance of the U-shaped shed used to support the negative coal pillar roadway, b is the width of the negative coal pillar roadway, u is o is the shed distance of the U-shaped shed, p z is the support resistance of the hydraulic support adapted to the U-shaped shed, u z is the distance between two adjacent hydraulic supports along the direction of the negative coal pillar roadway; s is the average displacement of the negative coal pillar roadway, U i is the dynamic load source energy of the i-th historical dynamic load, i∈I, I is the total number of historical dynamic loads; i and I are both positive integers, β1 is the attenuation coefficient of the shock wave energy in the roof rock layer or coal seam, and β2 is the attenuation coefficient of the shock wave energy in the broken coal seam.

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