Rock burst analysis method and system based on different coal-rock mass combination forms

Abstract

The invention relates to the technical field of coal rock safety, and provides a rock burst analysis method and system based on different coal rock combination forms. According to the method, the combination form of the combined coal-rock mass is determined according to the stress-strain relation of the combined coal-rock mass under the stress effect, so that strain softening models of the combined coal-rock mass in different combination forms are constructed for rock burst simulation, and elastic energy accumulation distribution of different layers of the combined coal-rock mass in different combination forms under the stress effect is determined; and determining combined anti-scour measures of the combined coal and rock masses in different combination forms under the action of the stress. Therefore, the characteristics of energy accumulation of each layer of various different coal-rock combination forms, the rules of shear failure and plastic failure of each layer of coal-rock mass, the elastic energy change and the elastic energy accumulation rule are analyzed theoretically, and targeted anti-scour measures are provided according to the change characteristics of each layer of coal-rock mass. And a theoretical basis is provided for deciding whether working faces with different combined coal-rock mass forms can be safely mined or not.

Description

Technical Field

[0001] The present application relates to the field of coal-rock safety technology, and in particular to a rock burst analysis method and system based on different coal-rock combination forms. Background Art

[0002] With the increase in mining intensity and depth, many rock burst accidents (including coal body impact, roof impact and floor impact) have been induced. The instability of the surrounding rock of the working face has induced rock burst accidents, large-scale mine earthquakes, and even underground rock bursts accompanied by mine earthquakes. This type of rock burst is often a catastrophic impact induced by the accumulation of large energy elastic properties in the coal rock mass, causing serious casualties and property losses.

[0003] At present, a lot of research has been done on the spatial structure of overburden, the distribution characteristics of support pressure, the preliminary assessment of impact hazard, the mechanism of rock burst, etc., and useful explorations have been made on the monitoring and early warning of rock burst. However, there is a lack of research on the inducing mechanism of rock burst in different coal-rock combinations and targeted prevention and control measures. It has become a safety issue of concern to coal mines to determine the destruction law of coal-rock masses with different combinations during stress loading, the change law of elastic energy density, the strata where rock burst occurs in coal-rock masses at different strata, and targeted three-dimensional anti-bumping measures. Summary of the invention

[0004] The purpose of this application is to provide a rock burst analysis method and system based on different coal-rock combination forms, so as to solve or alleviate the problems existing in the above-mentioned prior art.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] The present application provides a rock burst analysis method based on different coal-rock combination forms, including: step S101, determining the combination form of the combined coal-rock mass according to the stress-strain relationship of the combined coal-rock mass under stress; step S102, constructing a strain softening model of the combined coal-rock mass with different combination forms to perform rock burst simulation to determine the elastic energy accumulation distribution of different layers of the combined coal-rock mass with different combination forms under stress; step S103, determining the combined anti-rock measures of the combined coal-rock mass with different combination forms under stress according to the elastic energy accumulation distribution of different layers of the combined coal-rock mass with different combination forms under stress.

[0007] Preferably, in step S101, in response to ε 11 >ε 10 =ε 12 , then the combined coal-rock mass is a combination of hard roof-soft coal seam-hard floor; in response to ε 22 >ε 21 >ε 20, then the combined coal-rock mass is a combination of hard roof-hard coal seam-soft floor; in response to ε 30 >ε 31 >ε 32 , then the combined coal-rock mass is a combination of soft roof-hard coal seam-hard floor;

[0008] Among them, ε 12 , ε 11 , ε 10 ε is the strain of the bottom plate, coal seam and roof of the combined coal-rock mass under the same stress when the combined coal-rock mass is a combination of hard roof plate-soft coal seam-hard bottom plate; 22 , ε 21 , ε 20 are the strains of the bottom plate, coal seam and roof of the combined coal-rock mass under the same stress when the combined coal-rock mass is a combination of hard roof plate-hard coal seam-soft bottom plate; ε 32 , ε 31 , ε 30 They are respectively the strains of the roof, coal seam and floor in the combined coal rock mass under the same stress when the combined coal rock mass is in the combined form of soft roof-hard coal seam-hard floor.

[0009] Preferably, in response to the combined coal-rock mass being a combination of hard roof-soft coal seam-hard floor, the relationship of the elastic energy accumulated among the floor, coal seam and roof in the combined coal-rock mass is:

[0010]

[0011] In the formula, ε 12 , ε 11 , ε 10 is the strain of the bottom plate, coal seam and roof in the combined coal-rock mass under the same stress when the combined coal-rock mass is a combination of hard roof plate-soft coal seam-hard bottom plate; E 12 、E 11 、E 10 They are respectively the elastic energies accumulated in the bottom plate, coal seam and roof of the combined coal rock mass under the same stress when the combined coal rock mass is a combination of hard roof plate-soft coal seam-hard bottom plate; x is the thickness of each combined layer in the combined coal rock mass.

[0012] Preferably, in response to the combined coal-rock mass being a combination of hard roof-hard coal seam-soft floor, the relationship of the elastic energy accumulated among the floor, coal seam and roof in the combined coal-rock mass is:

[0013]

[0014] In the formula, ε 22 , ε 21 , ε 20are the strains of the bottom plate, coal seam and roof of the combined coal-rock mass under the same stress when the combined coal-rock mass is in the combined form of hard roof plate-hard coal seam-soft bottom plate; E 22 、E 21 、E 20 They are respectively the elastic energies accumulated in the bottom plate, coal seam and roof of the combined coal rock mass under the same stress when the combined coal rock mass is a combination of hard roof-hard coal seam-soft bottom plate; x is the thickness of each combined layer in the combined coal rock mass; x1 is the thickness of the top plate in the combined coal rock mass, x2 is the thickness of the coal seam in the combined coal rock mass, and x3 is the thickness of the bottom plate of the combined coal rock mass.

[0015] Preferably, in response to the combined coal-rock mass being a combination of soft roof-hard coal seam-hard floor, the relationship of the elastic energy accumulated among the floor, coal seam and roof in the combined coal-rock mass is:

[0016]

[0017] In the formula, ε 32 , ε 31 , ε 30 are the strains of the roof, coal seam and floor of the combined coal-rock mass under the same stress when the combined coal-rock mass is in the combined form of soft roof-hard coal seam-hard floor; E 32 、E 31 、E 30 They are respectively the elastic energies accumulated in the roof, coal seam and floor of the combined coal rock mass under the same stress when the combined coal rock mass is a combination of soft roof-hard coal seam-hard floor; x is the thickness of each combined layer in the combined coal rock mass; x1 is the thickness of the roof in the combined coal rock mass, x2 is the thickness of the coal seam in the combined coal rock mass, and x3 is the thickness of the floor of the combined coal rock mass.

[0018] Preferably, in step S102, rock burst simulation is performed on the strain softening model of the combined coal-rock mass in different combination forms to determine the plastic failure zone, shear failure characteristics, elastic energy distribution and elastic energy density distribution of the combined coal-rock mass in different combination forms under stress.

[0019] Preferably, in step S102, in response to the combined coal-rock mass being a combination of hard roof-soft coal seam-hard floor, the plastic failure zone, the maximum elastic energy distribution zone, and the maximum elastic energy density distribution zone of the combined coal-rock mass are all coal bodies, and the shear failure feature is instantaneous protrusion of the coal bodies;

[0020] In response to the combined coal-rock mass being a combined form of hard roof-hard coal seam-soft floor, the plastic failure zone of the combined coal-rock mass is the coal seam and the floor, the shear failure feature is the instantaneous protrusion of the floor, the area with the highest elastic energy density is the coal body, and the elastic energy has the highest accumulation degree in the coal body and gradually decreases from the core to the outside;

[0021] In response to the fact that the combined coal-rock mass is a combination of soft roof-hard coal seam-hard floor, the plastic failure zone of the combined coal-rock mass is the coal seam and the roof, the shear failure feature is mainly the instantaneous collapse of the roof, the area with the highest elastic energy density is the boundary area between the roof and the coal body, and the elastic energy accumulates to the highest degree in the coal body and gradually decreases from the core to the outside.

[0022] Preferably, step S103 comprises: in response to the combined coal-rock mass being a combination of hard roof-soft coal seam-hard floor, drilling and decompressing the coal body of the combined coal-rock mass;

[0023] In response to the combined coal-rock mass being a combination of hard roof-hard coal seam-soft floor, drilling to relieve pressure on the coal body of the combined coal-rock mass and breaking to relieve pressure on the floor of the combined coal-rock mass;

[0024] In response to the combined coal-rock mass being a combination of soft roof-hard coal seam-hard floor, the coal body of the combined coal-rock mass is decompressed by drilling, and the roof of the combined coal-rock mass is decompressed by blasting.

[0025] Preferably, the blasting and decompression of the roof of the combined coal-rock mass comprises: blasting and decompression of the roof of the combined coal-rock mass in two directions, parallel to the working face and parallel to the working face;

[0026] The bottom breaking and pressure relief of the bottom plate of the combined coal rock mass includes: blasting and pressure relief of the bottom coal of the tunnel with a thickness greater than 1 meter, wherein blasting drill holes are arranged along the direction of the tunnel and are vertically blasted to the bottom plate of the combined coal rock mass.

[0027] The embodiment of the present application also provides a rock burst analysis system based on different coal-rock combination forms, including: a combination form analysis unit configured to determine the combination form of the combined coal-rock mass according to the stress-strain relationship of the combined coal-rock mass under stress;

[0028] A combined morphology simulation unit is configured to construct a strain softening model of the combined coal-rock mass with different combined morphologies to perform rock burst simulation, so as to determine the elastic energy accumulation distribution of different layers of the combined coal-rock mass with different combined morphologies under stress;

[0029] The anti-bumping setting unit is configured to determine the combined anti-bumping measures of the combined coal rock mass with different combined forms under stress according to the elastic energy accumulation distribution of different layers of the combined coal rock mass with different forms under stress.

[0030] Beneficial effects:

[0031] In the rock burst analysis method based on different coal-rock combination forms provided in the embodiment of the present application, first, the combination form of the combined coal-rock mass is determined according to the stress-strain relationship of the combined coal-rock mass under stress; then, a strain softening model of the combined coal-rock mass with different combination forms is constructed to simulate rock burst to determine the elastic energy accumulation distribution of different layers of the combined coal-rock mass with different combination forms under stress; finally, according to the elastic energy accumulation distribution of different layers of the combined coal-rock mass with different combination forms under stress, the combined anti-impact measures of the combined coal-rock mass with different combination forms under stress are determined. Thus, the characteristics of energy accumulation of each layer of various coal-rock combination forms, the laws of shear failure and plastic failure of coal-rock mass at each layer, and the laws of elastic energy change and elastic energy accumulation are theoretically analyzed, and targeted anti-impact measures are proposed according to the change characteristics of coal-rock mass at each layer, providing a theoretical basis for deciding whether the working faces of different coal-rock combination forms can be mined safely. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. Among them:

[0033] Figure 1 A schematic flow chart of a rock burst analysis method based on different coal-rock combination forms provided according to some embodiments of the present application;

[0034] Figure 2 A stress-strain curve of a combined coal-rock mass with a combined form of hard roof-soft coal seam-hard floor provided according to some embodiments of the present application;

[0035] Figure 3 A stress-strain curve of a combined coal-rock mass with a combined form of hard roof-hard coal seam-soft floor provided according to some embodiments of the present application;

[0036] Figure 4 A stress-strain curve of a combined coal-rock mass with a combined form of soft roof-hard coal seam-hard floor provided according to some embodiments of the present application;

[0037] Figure 5 A schematic diagram of plastic failure of a combined coal-rock mass having a hard roof-soft coal seam-hard floor provided in some embodiments of the present application;

[0038] Figure 6 A schematic diagram of plastic failure of a combined coal-rock mass having a hard roof-hard coal layer-soft floor provided in some embodiments of the present application;

[0039] Figure 7 A schematic diagram of plastic failure of a combined coal-rock mass having a combined form of soft roof-hard coal seam-hard floor provided according to some embodiments of the present application;

[0040] Figure 8 A schematic diagram of shear failure of a combined coal-rock mass having a hard roof-soft coal seam-hard floor provided in some embodiments of the present application;

[0041] Fig. 9 A schematic diagram of shear failure of a combined coal-rock mass having a combined form of hard roof-hard coal seam-soft floor provided according to some embodiments of the present application;

[0042] Fig.10 A schematic diagram of shear failure of a combined coal-rock mass having a combined form of soft roof-hard coal seam-hard floor provided according to some embodiments of the present application;

[0043] Fig.11 A schematic diagram of elastic energy density distribution of a combined coal-rock mass having a combined form of hard roof-soft coal seam-hard floor provided according to some embodiments of the present application;

[0044] Fig.12 A schematic diagram of elastic energy density distribution of a combined coal-rock mass having a combined form of hard roof-hard coal seam-soft floor provided according to some embodiments of the present application;

[0045] Fig.13 A schematic diagram of elastic energy density distribution of a combined coal-rock mass having a combined form of soft roof-hard coal seam-hard floor provided according to some embodiments of the present application;

[0046] Fig.14 A schematic diagram of elastic energy distribution of a combined coal-rock mass having a combined form of hard roof-soft coal seam-hard floor provided according to some embodiments of the present application;

[0047] Fig.15 A schematic diagram of elastic energy distribution of a combined coal-rock mass having a combined form of hard roof-hard coal seam-soft floor provided according to some embodiments of the present application;

[0048] Fig.16 A schematic diagram of elastic energy distribution of a combined coal rock mass having a combined form of soft roof-hard coal seam-hard floor provided according to some embodiments of the present application;

[0049] Fig.17 A schematic diagram of the structure of a rock burst analysis system based on different coal-rock combination forms provided according to some embodiments of the present application. DETAILED DESCRIPTION

[0050] 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.

[0051] At present, there is still a lack of effective theoretical basis for the plastic failure, shear failure, elastic energy density and elastic energy accumulation degree of different "roof-coal seam-floor" coal-rock combination forms, as well as the damaged strata of different combinations of coal and rock masses during stress loading and targeted three-dimensional anti-bumping measures. There is still a lack of effective theoretical basis for the engineering problems of which high isolated island working faces to mine, which not to mine, and which can be mined after taking anti-bumping measures. The resulting impact ground pressure has caused huge casualties and property losses.

[0052] First of all, it should be noted that the distinction between "hard" and "soft" of the roof, coal seam, and floor in this application is only based on the relative relationship between the hardness of the roof, coal seam, and floor in the combined coal rock mass under the same conditions. For example, hard roof-soft coal seam-hard floor means that in the same combined coal rock mass, the hardness of the coal seam is relatively less than the hardness of the roof and the floor; hard roof-hard coal seam-soft floor means that in the same combined coal rock mass, the hardness of the floor is relatively less than the hardness of the roof and the coal seam; soft roof-hard coal seam-hard floor means that in the same combined coal rock mass, the hardness of the roof is relatively less than the hardness of the coal seam and the floor. In other words, "hard" and "soft" are the relative relationship between the hardness of the roof, coal seam, and floor in the same combined coal rock mass, rather than absolute values. Here, the roof and floor with a hardness of less than 20MPa are defined as soft rock, and the hardness of greater than or equal to 20MPa is defined as hard rock; the coal seam with a hardness of less than 10MPa is defined as a soft coal seam, and the hardness of greater than or equal to 10MPa is defined as a hard coal seam.

[0053] Based on this, this application analyzes the three-dimensional anti-bumping corresponding to the various plastic and shear failure layers and the elastic energy density and elastic energy accumulation layers under the three forms of different coal-rock combinations "soft coal seam + hard roof and floor", "hard roof + hard coal seam + soft floor", and "hard floor + hard coal body + soft roof" during stress loading. The characteristics of energy accumulation in each layer of different coal-rock combination forms, the laws of shear failure and plastic failure of coal and rock masses in each layer, and the laws of elastic energy changes and elastic energy accumulation are theoretically analyzed. According to the changing characteristics of coal and rock masses in each layer, targeted anti-bumping measures are proposed, which provide a theoretical basis for deciding whether working faces with different combinations of coal and rock forms can be safely mined.

[0054] like Figures 1 to 16 As shown in FIG. 1 , the rock burst analysis method based on different coal-rock combination forms includes:

[0055] Step S101, determining the combined form of the combined coal-rock mass according to the stress-strain relationship of the combined coal-rock mass under stress.

[0056] According to the influencing factors of rock burst mines, rock burst mines can be divided into six different types. The first type is the self-weight impact of deep burial depth, thin bedrock and thick coal seams; the second type is the high-intensity mining impact of deep burial depth, full bedrock and thick coal seams; the third type is the coal pillar impact of coal seam group mining; the fourth type is the coupled impact of compound disasters in shallow burial depth and extra-thick coal seams; the fifth type is the impact of complex structure and irregular block mining; the sixth type is the impact of deep burial depth key layer action.

[0057] With the influence of factors such as mining depth, mining intensity, and inadequate pressure relief, the degree of damage to tunnels caused by rock burst accidents increases year by year; and the areas where rock burst damage occurs are also different. Some mines are mainly severely damaged in the coal seam area, some mines have serious damage to the roof and coal seam, and some mines have serious damage to the coal seam and floor, etc. When rock burst occurs in the mine, it causes great damage to the personnel, tunnels, etc. of the mine. In this application, the geological conditions of rock burst in different regions and the positions of the roof, coal seam, and floor after the rock burst occur are analyzed, and the combined form of the combined coal rock mass is determined according to the stress-strain relationship of the combined coal rock mass under stress, so as to achieve multi-position three-dimensional joint precise pressure relief in space under the lithological conditions of the roof, coal seam, and floor with different combinations.

[0058] Specifically, the combined form of the combined coal-rock mass is determined according to the stress-strain relationship of different layers of the combined coal-rock mass under stress. 11 >ε 10 =ε 12When , the strain of the coal body in the combined coal-rock mass is the largest, and the strains of the roof and floor are the same. In other words, the hardness of the coal seam in the combined coal-rock mass is relatively small, and the hardness of the roof and floor are both greater than that of the coal seam. The combined coal-rock mass is a combination of hard roof-soft coal seam-hard floor. 12 , ε 11 , ε 10 It is the strain of roof, coal seam and floor in the combined coal-rock mass with the combination form of hard roof-soft coal seam-hard floor under the same stress.

[0059] When the combined coal-rock mass is a combination of hard roof-soft coal seam-hard floor, the hardness of the coal body is small and the strain is large; under the same stress, the energy storage relationship of the roof, coal seam and floor in the combined coal-rock mass is as follows:

[0060]

[0061] Among them, X is the thickness of each combined layer in the combined coal rock mass, E 12 、E 11 、E 10 They are respectively the elastic energy accumulated in the bottom plate, coal seam and roof of the combined coal-rock mass under the same stress when the combined coal-rock mass is in the combined form of hard roof-soft coal seam-hard bottom plate. It can be seen that when the combined coal-rock mass is in the combined form of hard roof-soft coal seam-hard bottom plate, the elastic strain energy accumulated in the soft coal seam is the largest. The soft coal seam is used as the pressure relief layer for targeted pressure relief, so that the energy release is more thorough and the crisis relief effect is better.

[0062] Under the same stress, when ε 22 >ε 21 >ε 20 When , the strain of the bottom plate in the combined coal-rock mass is the largest, and the strain of the top plate is the smallest. In other words, the hardness of the bottom plate in the combined coal-rock mass is the smallest, and the hardness of the top plate and the coal seam are both greater than the hardness of the bottom plate. Therefore, the combined coal-rock mass is a combination of hard roof plate-hard coal seam-soft bottom plate. Among them, ε 22 , ε 21 , ε 20 It is the strain of roof, coal seam and floor in the combined coal-rock mass with the combination form of hard roof-hard coal seam-soft floor under the same stress.

[0063] When the combined coal-rock mass is a combination of hard roof-hard coal seam-soft floor, the floor is relatively soft, the coal layer is second, and the roof has the largest hardness; the strain is the largest in the floor, the second in the coal layer, and the smallest in the roof. Under the same stress, the energy storage relationship among the roof, coal seam, and floor in the combined coal-rock mass is as follows:

[0064]

[0065] Among them, E 22 、E21 、E 20 They are the elastic energies accumulated in the bottom plate, coal seam and roof of the combined coal-rock mass under the same stress when the combined coal-rock mass is a combination of hard roof plate-hard coal seam-soft bottom plate. x is the thickness of each combined layer in the combined coal-rock mass; x1 is the thickness of the combined layer-top plate in the combined coal-rock mass, x2 is the thickness of the combined layer-coal seam in the combined coal-rock mass, and x3 is the thickness of the combined layer-bottom plate in the combined coal-rock mass.

[0066] Under the same stress, when ε 30 >ε 31 >ε 32 When , the strain of the bottom plate in the combined coal-rock mass is the largest, and the strain of the top plate is the smallest, that is, the hardness of the bottom plate in the combined coal-rock mass is the smallest, and the hardness of the coal seam and the bottom plate is greater than that of the roof plate. Therefore, the combined coal-rock mass is a combination of soft roof-hard coal seam-hard bottom plate. Among them, ε 30 , ε 31 , ε 32 It is the strain of roof, coal seam and floor in the combined coal-rock mass with the combination form of soft roof-hard coal seam-hard floor under the same stress.

[0067] When the combined coal-rock mass is a combination of soft roof-hard coal seam-hard floor, the hardness of the floor is the largest, followed by the coal seam, and the roof is the softest; the strain is the smallest in the floor, followed by the coal seam, and the roof has the smallest strain. Under the same stress, the energy storage relationship of the roof, coal seam, and floor in the combined coal-rock mass is as follows:

[0068]

[0069] Among them, E 32 、E 31 、E 30 They are the elastic energies accumulated in the roof, coal seam and floor of the combined coal-rock mass under the same stress when the combined coal-rock mass is a combination of soft roof-hard coal seam-hard floor. x is the thickness of each combined layer in the combined coal-rock mass; x1 is the thickness of the combined layer-roof in the combined coal-rock mass, x2 is the thickness of the combined layer-coal seam in the combined coal-rock mass, and x3 is the thickness of the combined layer-floor in the combined coal-rock mass.

[0070] Step S102: construct a strain softening model of the combined coal-rock mass with different combinations to perform a rock burst model, so as to determine the elastic energy accumulation distribution of different layers of the combined coal-rock mass with different combinations under stress.

[0071] After determining the combined form of the combined coal-rock mass through the stress-strain relationship of the combined coal-rock mass, the elastic energy accumulation distribution of the combined coal-rock mass with different combined forms under stress is determined by simulating rock burst pressure on the combined coal-rock mass with different combined forms. Specifically, a strain softening model of the combined coal-rock mass is constructed based on the physical parameters of the combined coal-rock mass. The strain softening model for rock burst pressure simulation is mainly constructed based on the uniaxial compressive strength, elastic modulus, Poisson's ratio, tensile strength, cohesion and internal friction angle of the combined coal-rock mass. Combined coal-rock masses with different combined forms are constructed by setting parameters of different physical properties.

[0072] Here, the combined coal-rock mass with the combination of hard roof-soft coal seam-hard floor, hard roof-hard coal seam-soft floor, and soft roof-hard coal seam-hard floor is constructed mainly through roofs, coal bodies and floors with different hardness. The plastic failure zone, shear failure characteristics, elastic energy distribution and elastic energy density distribution of the combined coal-rock mass with different combination forms are determined through the rock burst model of different strain softening models.

[0073] For the strain softening model with a combination of hard roof-soft coal seam-hard floor, during the stress loading process, due to the softness of the coal seam, the accumulated elastic deformation energy is the largest and reaches the failure limit first, and the plastic deformation zone is mainly distributed in the coal seam; the shear failure zone of the strain softening model occurs in the coal body and is in the shape of two opposing funnels, and the shear failure feature is mainly the instantaneous protrusion of the coal body.

[0074] During the stress loading process, the area with the largest elastic energy density distribution of the strain softening model with a combination of hard roof-soft coal seam-hard floor is the coal body, and it is in the shape of an I. The elastic energy distribution in the coal body is the largest, and the elastic energy accumulation degree of the roof and floor is relatively low. For the coal body with the largest elastic energy distribution, the elastic energy mainly accumulates at the edge of the coal body. When impact ground pressure occurs, the tunnel damage is most serious.

[0075] For the strain softening model with a combination of hard roof-hard coal seam-soft floor, the floor is relatively soft, especially in a large water mine. The strength of the floor will be further reduced after encountering water. During the stress loading process, the plastic failure of the floor will further extend to the coal body, causing the coal body to be linked to plastic failure. Therefore, when the floor is relatively soft, the combined coal-rock mass is in the combination of hard roof-hard coal seam-soft floor. Under high stress, the damage is mainly concentrated in the coal seam and floor, that is, the plastic crushing area is the coal seam and floor. During the stress loading process, the main shear failure of the strain softening model occurs in the floor, and it is in the shape of a funnel with an opening downward. Therefore, when the rock burst occurs, the main feature of the shear failure is the instantaneous protrusion of the floor.

[0076] When the combination is hard roof-hard coal seam-soft floor, since the floor is relatively soft and the coal body lacks support, part of the energy is released during the bottom bulging of the floor during stress loading, and the elastic energy is transferred to the coal body, resulting in the highest elastic energy density of the coal body, and the elastic energy accumulation gradually decreases from the core to the outside, especially in the area connecting the corners of the floor and the center of the coal body core, presenting a funnel shape with an opening downward. When impact ground pressure occurs, it is not only manifested as the protrusion of the coal body, but also accompanied by floor impact.

[0077] For the strain softening model with a combination of soft roof-hard coal seam-hard floor, the roof is relatively soft. During the stress loading process, when the roof undergoes plastic failure, the plastic failure will further extend to the coal body, causing linked plastic failure of the coal body. Therefore, when the roof is relatively soft, under the action of stress, the failure is mainly concentrated in the coal seam and the roof, that is, the plastic failure zone is mainly the coal seam and the roof; the shear failure area mainly occurs in the roof and is in the shape of a funnel opening upward. When rock burst occurs, the shear failure feature is mainly manifested as the instantaneous fall of the roof.

[0078] When the combination is soft roof-hard coal seam-hard floor, during stress loading, the area with the highest elastic energy density is the interface between the roof and the coal body, followed by the coal body, and the floor has the lowest elastic energy density. The elastic energy accumulates most in the coal body and gradually decreases from the core to the outside; the area with the largest accumulation of floor elastic energy is in the area connecting the bottom corners and the center of the coal body core, which is in the shape of a funnel with an opening upward. Therefore, when rock burst occurs, it is not only manifested as coal protrusion, but also accompanied by roof collapse.

[0079] Step S103, determining combined anti-bumping measures for combined coal-rock masses with different combined forms under stress according to the elastic energy accumulation distribution of different layers of combined coal-rock masses with different combined forms under stress.

[0080] The rock burst simulation of combined coal-rock masses with different combinations was carried out through the strain softening model, and the elastic energy accumulation of combined coal-rock masses with different combinations in different strata was obtained. It can be seen that when stress is loaded, no matter it is a combination of hard roof-soft coal seam-hard bottom plate, hard roof-hard coal seam-soft bottom plate, or soft roof-hard coal seam-hard bottom plate, the coal body will experience plastic and shear failure, and the elastic energy density and elastic energy are very high. Therefore, drilling pressure relief is required for the coal bodies in the combined coal-rock masses with all combinations.

[0081] When the combined coal rock mass is in the form of a hard roof-hard coal seam-soft floor, the roof will experience plastic and shear failure during stress loading, with high elastic energy density and high elastic energy. The roof is in danger of rock burst. In order to prevent rock burst from occurring on the roof during mining of the working face, the roof must be blasted to relieve pressure.

[0082] The reason for the impact of the bottom coal or the thin and soft bottom rock layer in the tunnel is that the concentration of stress on both sides of the tunnel is too large, which causes plastic shear failure of the bottom plate. The bottom coal has an impact tendency and can store the bending elastic energy formed by the horizontal stress. Since the bottom plate of the tunnel is unsupported, the bottom plate after plastic failure is not constrained, and the stored bending elastic energy and the compressive elastic energy transmitted by the coal side are released instantly, causing the bottom coal to rush into the tunnel. Although the bottom coal cannot provide a force source for the occurrence of rock burst, it becomes a disaster-causing body for the manifestation of rock burst. Therefore, effective measures should be taken to cut off the energy and stress transmission path between the force source and the bottom coal or the thin and soft bottom rock layer disaster body. In other words, it is necessary to blast and unload the bottom coal with a thickness greater than 1 meter in the tunnel (the coal seam is at or below the bottom plate of the tunnel, and the rock pillar is less than 1 meter), that is, to break the bottom pressure relief.

[0083] Therefore, when the combined coal-rock mass is in the form of a combination of hard roof-soft coal seam-hard floor, when stress is loaded, the coal body undergoes plastic and shear failure, and the elastic energy density and elastic energy are very high. The impact risk is mainly concentrated in the coal body. At this time, the coal body of the combined coal-rock mass needs to be drilled to relieve pressure.

[0084] When the combined coal-rock mass is a combination of hard roof-hard coal seam-soft floor, the coal body undergoes plastic failure, and the elastic energy density and elastic energy are very high. The floor undergoes plastic and shear failure, and the elastic energy density and elastic energy are very high. The impact risk is mainly concentrated in the coal body and floor area. At this time, it is necessary to drill to relieve pressure on the coal body in the combined coal-rock mass, and to break the bottom to relieve pressure on the floor in the combined coal-rock mass.

[0085] When the combined coal-rock mass is in the form of a combination of soft roof-hard coal seam-hard floor, the coal body undergoes plastic failure, with a high elastic energy density and a high degree of elastic energy accumulation; the roof undergoes plastic and shear failure, with a high elastic energy density and a high degree of elastic energy accumulation; the impact risk is mainly concentrated in the coal body and roof areas. At this time, it is necessary to drill to relieve pressure on the coal body in the combined coal-rock mass, and to blast to relieve pressure on the roof in the combined coal-rock mass.

[0086] In a specific example, when blasting to relieve pressure on the roof in a combined coal rock mass, the roof pressure relief is divided into two directions. One is parallel to the working face, that is, the inclination direction of the borehole is parallel to the working face, so as to make an advance determination, reduce the length of the roof break, and reduce the intensity of dynamic load disturbance when the working face is mined; the other is parallel to the direction of the working face, so as to reduce the horizontal stress effect, reduce the accumulation of elastic energy, and reduce the degree of damage to the tunnel support caused by dynamic load disturbance when the working face is mined.

[0087] In another specific example, when the bottom plate of the combined coal-rock mass is broken and decompressed, holes are drilled in the tunnel floor, and explosives are charged and blasted to destroy the floor structure, so that energy is released, the stress level of the floor is reduced, and the high stress is transferred to the deep part of the floor, thereby eliminating the danger of floor impact. Specifically, blasting is performed to decompress the bottom coal of the tunnel with a thickness greater than 1 meter, and the blasting holes are arranged along the direction of the tunnel and are vertical to the bottom plate of the combined coal-rock mass and blasted to the bottom plate of the combined coal-rock mass.

[0088] Among them, the depth of the drill hole is determined by the thickness of the bottom coal, and must be drilled to the bottom of the coal seam; at least 3 drill holes are arranged along the direction of the tunnel, of which 1 is arranged in the tunnel and drilled vertically at the bottom plate; 1 is arranged at each bottom corner of the two sides, and the drill holes on the two sides are 0.3 to 0.5 meters away from the bottom corner of the tunnel, arranged at 75 degrees to the center line of the tunnel, and the drill hole spacing is 3 meters; forward charging is adopted, and the holes are connected in parallel inside and in series outside when connected; each drill hole is loaded with 2-6 charges, and the charging amount is adjusted according to the hole depth and blasting effect. When there are less than 3 charges, such as flower explosives, 1 electric detonator is used for detonation, and when there are more than 3 charges, such as emulsion explosives, no less than 2 electric detonators are used for detonation.

[0089] Therefore, according to the stress and strain of different combinations of coal-rock masses, a model of the relationship between energy storage field, stress field and strain field is established, the energy storage capacity of each stratum of the combined coal-rock mass is theoretically analyzed, and the disaster-causing mechanism of different combinations of coal-rock masses is analyzed from the perspective of energy field.

[0090] By analyzing the stress concentration areas, energy accumulation areas, layer damage areas of combined coal-rock masses with different combinations and the transfer laws of stress fields and energy storage fields after the combined coal-rock masses are destroyed, the mutual feedback relationship between stress field-energy field-destruction zone and the intrinsic connection between stress field-energy field-destruction zone-transferred stress field-transferred energy field are revealed. The plastic failure and shear failure layers and the elastic energy density and elastic energy accumulation layers in the stress loading process are corresponded to the impact rock pressure failure, and three-dimensional joint pressure relief measures for multi-layers with different combinations in different spaces are formulated.

[0091] like Fig.17 As shown, the embodiment of the present application also provides a rock burst analysis system based on different coal-rock combination forms, including:

[0092] The combined morphology analysis unit 1701 is configured to determine the combined morphology of the combined coal-rock mass according to the stress-strain relationship of the combined coal-rock mass under stress;

[0093] The combined morphology simulation unit 1702 is configured to construct a strain softening model of a combined coal-rock mass with different combined morphologies to perform a rock burst model, so as to determine the elastic energy accumulation distribution at different layers of the combined coal-rock mass with different combined morphologies under stress;

[0094] The anti-bumping setting unit 1703 is configured to determine the combined anti-bumping measures of the combined coal-rock masses with different combined forms under stress according to the elastic energy accumulation distribution of different layers of the combined coal-rock masses with different forms under stress.

[0095] The rock burst analysis system based on different coal-rock combination forms provided in the embodiment of the present application can implement the steps and processes of the rock burst analysis method based on different coal-rock combination forms of any of the above-mentioned embodiments, and achieve the same technical effects, which will not be described one by one here.

[0096] In the description of the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. 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.

[0097] 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 rock burst analysis method based on different coal-rock combination forms, characterized in that: include: Step S101, determining the combined morphology of the combined coal-rock mass according to the stress-strain relationship of the combined coal-rock mass under stress; Step S102, constructing a strain softening model of the combined coal-rock mass with different combined forms to perform rock burst simulation, so as to determine the elastic energy accumulation distribution of different layers of the combined coal-rock mass with different combined forms under stress; Step S103, determining the combined anti-collision measures of the combined coal-rock mass with different combined forms under stress according to the elastic energy accumulation distribution of different layers of the combined coal-rock mass with different combined forms under stress.

2. The rock burst analysis method based on different coal-rock combination forms according to claim 1 is characterized in that: In step S101, In response to ε 11 >ε 10 =ε 12 , then the combined coal-rock mass is a combination of hard roof-soft coal seam-hard floor; In response to ε 22 >ε 21 >ε 20 , then the combined coal-rock mass is a combination of hard roof-hard coal seam-soft floor; In response to ε 30 >ε 31 >ε 32 , then the combined coal-rock mass is a combination of soft roof-hard coal seam-hard floor; Among them, ε 12 , ε 11 , ε 10 is the strain of the bottom plate, coal seam and roof in the combined coal rock mass under the same stress when the combined coal rock mass is in the combined form of hard roof plate-soft coal seam-hard bottom plate; ε 22 , ε 21 , ε 20 are respectively the strains of the bottom plate, coal seam and roof plate in the combined coal rock mass under the same stress when the combined coal rock mass is in the combined form of hard roof plate-hard coal seam-soft bottom plate; ε 32 , ε 31 , ε 30 They are respectively the strains of the roof, coal seam and floor in the combined coal rock mass under the same stress when the combined coal rock mass is in the combined form of soft roof-hard coal seam-hard floor.

3. The rock burst analysis method based on different coal-rock combination forms according to claim 2 is characterized in that: In response to the combined coal-rock mass being a combination of hard roof-soft coal seam-hard floor, the relationship of the elastic energy accumulated among the floor, coal seam and roof in the combined coal-rock mass is: In the formula, ε 12 , ε 11 , ε 10 is the strain of the bottom plate, coal seam and roof in the combined coal rock mass under the same stress when the combined coal rock mass is in the combined form of hard roof plate-soft coal seam-hard bottom plate; E 12 、E 11 、E 10 are respectively the elastic energies accumulated in the bottom plate, coal seam and roof of the combined coal-rock mass under the same stress when the combined coal-rock mass is in the combined form of hard roof plate-soft coal seam-hard bottom plate; x is the thickness of each combined layer in the combined coal rock mass.

4. The rock burst analysis method based on different coal-rock combination forms according to claim 2 is characterized in that: In response to the combined coal-rock mass being a combination of hard roof-hard coal seam-soft floor, the relationship of the elastic energy accumulated among the floor, coal seam and roof in the combined coal-rock mass is: In the formula, ε 22 , ε 21 , ε 20 are respectively the strains of the bottom plate, coal seam and roof plate in the combined coal rock mass under the same stress when the combined coal rock mass is in the combined form of hard roof plate-hard coal seam-soft bottom plate; E 22 、E 21 、E 20 are respectively the elastic energies accumulated in the bottom plate, coal seam and roof of the combined coal-rock mass under the same stress when the combined coal-rock mass is in the combined form of hard roof plate-hard coal seam-soft bottom plate; x is the thickness of each combined layer in the combined coal-rock mass; x1 is the thickness of the roof in the combined coal-rock mass, x2 is the thickness of the coal seam in the combined coal-rock mass, and x3 is the thickness of the bottom plate of the combined coal-rock mass.

5. The rock burst analysis method based on different coal-rock combination forms according to claim 2, characterized in that: In response to the combined coal-rock mass being a combination of soft roof-hard coal seam-hard floor, the relationship of the elastic energy accumulated among the floor, coal seam and roof in the combined coal-rock mass is: In the formula, ε 32 , ε 31 , ε 30 are respectively the strains of the roof, coal seam and floor in the combined coal rock mass under the same stress when the combined coal rock mass is in the combined form of soft roof-hard coal seam-hard floor; E 32 、E 31 、E 30 are respectively the elastic energies accumulated in the roof, coal seam and floor of the combined coal rock mass under the same stress when the combined coal rock mass is in the combined form of soft roof-hard coal seam-hard floor; x is the thickness of each combined layer in the combined coal-rock mass; x1 is the thickness of the roof in the combined coal-rock mass, x2 is the thickness of the coal seam in the combined coal-rock mass, and x3 is the thickness of the bottom plate of the combined coal-rock mass.

6. The rock burst analysis method based on different coal-rock combination forms according to claim 1, characterized in that: In step S102, The rock burst simulation is carried out on the strain softening model of the combined coal-rock mass in different combination forms to determine the plastic failure zone, shear failure characteristics, elastic energy distribution and elastic energy density distribution of the combined coal-rock mass in different combination forms under stress.

7. The rock burst analysis method based on different coal-rock combination forms according to claim 5, characterized in that: In step S102, In response to the combined coal-rock mass being a combined form of hard roof-soft coal seam-hard floor, the plastic failure zone, the maximum elastic energy distribution zone, and the maximum elastic energy density distribution zone of the combined coal-rock mass are all coal bodies, and the shear failure feature is instantaneous protrusion of the coal bodies; In response to the combined coal-rock mass being a combined form of hard roof-hard coal seam-soft floor, the plastic failure zone of the combined coal-rock mass is the coal seam and the floor, the shear failure feature is the instantaneous protrusion of the floor, the area with the highest elastic energy density is the coal body, and the elastic energy has the highest accumulation degree in the coal body and gradually decreases from the core to the outside; In response to the fact that the combined coal-rock mass is a combination of soft roof-hard coal seam-hard floor, the plastic failure zone of the combined coal-rock mass is the coal seam and the roof, the shear failure feature is mainly the instantaneous collapse of the roof, the area with the highest elastic energy density is the boundary area between the roof and the coal body, and the elastic energy accumulates to the highest degree in the coal body and gradually decreases from the core to the outside.

8. The rock burst analysis method based on different coal-rock combination forms according to claim 1, characterized in that: Step S103 includes: In response to the combined coal-rock mass being a combination of hard roof-soft coal seam-hard floor, drilling to relieve pressure on the coal body of the combined coal-rock mass; In response to the combined coal-rock mass being a combination of hard roof-hard coal seam-soft floor, drilling to relieve pressure on the coal body of the combined coal-rock mass and breaking to relieve pressure on the floor of the combined coal-rock mass; In response to the combined coal-rock mass being a combination of soft roof-hard coal seam-hard floor, the coal body of the combined coal-rock mass is decompressed by drilling, and the roof of the combined coal-rock mass is decompressed by blasting.

9. The rock burst analysis method based on different coal-rock combination forms according to claim 8, characterized in that: The blasting and decompression of the roof of the combined coal-rock mass comprises: Depressurizing the roof of the combined coal and rock mass by blasting in two directions parallel to the working face and parallel to the working face; The bottom breaking and pressure relief of the bottom plate of the combined coal-rock mass comprises: The bottom coal of the tunnel with a thickness greater than 1 meter is blasted to relieve pressure, and the blasting drill holes are arranged along the direction of the tunnel and are injected vertically to the bottom plate of the combined coal and rock mass.

10. A rock burst analysis system based on different coal-rock combination forms, characterized in that: include: A combined morphology analysis unit configured to determine the combined morphology of the combined coal-rock mass according to a stress-strain relationship of the combined coal-rock mass under stress; A combined morphology simulation unit is configured to construct a strain softening model of the combined coal-rock mass with different combined morphologies to perform rock burst simulation, so as to determine the elastic energy accumulation distribution of different layers of the combined coal-rock mass with different combined morphologies under stress; The anti-bumping setting unit is configured to determine the combined anti-bumping measures of the combined coal rock mass with different combined forms under stress according to the elastic energy accumulation distribution of different layers of the combined coal rock mass with different forms under stress.

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