A horizontal sub-level fully mechanized caving mining simulation method and system based on rolling resistance

Abstract

The present invention discloses a horizontal segmented fully mechanized top-caving mining simulation method and system based on rolling resistance, which belongs to the technical field of numerical simulation of mining engineering, and includes: establishing a basic model for numerical simulation of horizontal segmented fully mechanized top-caving mining; improving the contact model of the basic model for numerical simulation of horizontal segmented fully mechanized top-caving mining into a rolling resistance linear model, and setting the microscopic parameters and damping coefficient of the rolling resistance linear model to obtain an improved basic model for numerical simulation of horizontal segmented fully mechanized top-caving mining; setting a coal placing program, and calling the coal placing program in the improved basic model for numerical simulation of horizontal segmented fully mechanized top-caving mining to perform numerical simulation of horizontal segmented fully mechanized top-caving mining. The present invention proposes a simulation method that takes spherical particles as the smallest bulk particle unit and uses a contact model that considers rolling resistance. By considering the rolling resistance between particles, it can be equivalent to considering the influence of particle shape, so that the simulation results are closer to the theoretical model and similar simulation experiments.

Description

Technical Field

[0001] The invention relates to the technical field of numerical simulation of mining engineering, and more particularly to a horizontal segmented fully mechanized caving mining simulation method and system based on rolling resistance. Background Art

[0002] In some mining areas, there are steeply inclined and extra-thick coal seams. The coal resources contained in these coal seams, such as coking coal and other scarce coal species, have great mining value. In order to effectively mine these thick coal seams, comprehensive mechanized top coal caving mining technology came into being, among which horizontal segmented fully mechanized caving mining technology has become one of the main means. Studying the top coal caving law of the top coal caving working face is of great significance for guiding production operations and improving the top coal recovery rate.

[0003] However, there are many limitations in the current research methods on the caving law of top coal caving working faces. Although the similar simulation test of top coal caving can better reflect the real caving law, the experimental preparation is cumbersome, requiring the construction of a large test bench, the laying of a large number of loose particles and the production of suitable small top coal caving supports. In addition, the test results obtained by this test method are often limited to the recovery rate and the morphology of the coal-rock interface, and it is impossible to perform an effective inversion of the caving body. Therefore, the test results are relatively single and it is impossible to comprehensively analyze the displacement field, force chain distribution and particle migration characteristics of the mining area. At the same time, during the test, the top coal and gangue particles are continuously released from the caving port. In the similar simulation of horizontal segmented fully mechanized caving mining, the caving height is relatively large, which poses a certain safety threat to the experimental personnel.

[0004] In order to make up for the shortcomings of physical experiments, numerical simulation has been widely used in all walks of life as an efficient research method. Compared with physical experiments, numerical simulation does not require the purchase of experimental equipment such as loose particles and small top coal supports, nor does it require the processing and laying of loose particles, so it is more operable. When performing numerical simulation, users can easily arrange marker lines in the model and extract microscopic data such as particle displacement fields, while recording the position information of each particle in the mining area, and easily realize the inversion of the released body. This makes numerical simulation more advantageous in analyzing experimental results such as displacement field distribution and released body morphology during the experiment.

[0005] However, there are still many problems with the existing numerical simulation methods. The numerical simulation method of top coal caving using Linear Model as the contact model does not consider the influence of the shape of the real loose coal rock, resulting in a large difference between the simulation results and the theoretical model and similar simulation test results. The numerical simulation method using Cluster or Clump units as loose particles will reduce the efficiency of numerical simulation and increase the calculation time due to the increase in model complexity, and the simulation accuracy will also be affected. More importantly, whether it is the numerical simulation of top coal caving using Linear Model or Cluster or Clump units considering particle shape, the performance in the numerical simulation of horizontal segmented fully-mechanized caving working face will increase the simulation error as the top coal particles increase (increase in segment height), making the existing simulation method less applicable in the numerical simulation of horizontal segmented fully-mechanized mining.

[0006] Therefore, how to provide a mining numerical simulation method and system with high stability is a problem that technical personnel in this field need to solve urgently. Summary of the invention

[0007] In view of this, the present invention provides a horizontal segmented fully-mechanized caving mining simulation method and system based on rolling resistance. The use of a contact model based on rolling (friction) resistance can better simulate the influence of non-spherical particle shapes, making the model have better stability.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] On the one hand, the present invention provides a horizontal segmented fully mechanized caving mining simulation method based on rolling resistance, comprising:

[0010] Establish a basic model for numerical simulation of horizontal segmented fully mechanized top-caving mining;

[0011] The contact model of the horizontal sub-level fully-mechanized top-caving mining numerical simulation basic model is improved into a rolling resistance linear model, and the microscopic parameters and damping coefficient of the rolling resistance linear model are set to obtain an improved horizontal sub-level fully-mechanized top-caving mining numerical simulation basic model;

[0012] A coal caving program is set, and the coal caving program is called in the improved horizontal segmented fully-mechanized caving mining numerical simulation basic model to perform horizontal segmented fully-mechanized caving mining numerical simulation.

[0013] Preferably, a basic model for numerical simulation of horizontal segmented fully mechanized caving mining is established, including:

[0014] Constructing a horizontal segmented fully mechanized caving working face framework, wherein the horizontal segmented fully mechanized caving working face framework includes: a roof area, a floor area, a gangue layer area, a coal seam area, and a coal caving opening area;

[0015] Generating roof rock particles and bottom rock particles in the roof region and the bottom region respectively, fixing the speeds of the roof rock particles and the bottom rock particles, and completing the construction of the roof model and the bottom model;

[0016] Generating coal seam particles of target coal seam height in the coal seam area to complete the construction of the coal seam model;

[0017] The speed of the coal seam particles is fixed, and gangue particles of a target gangue layer height are generated on the coal seam particles to complete the construction of the gangue layer model;

[0018] The fixed speed of the coal seam particles is released, the coal seam particles and the gangue particles are balanced, and the gangue particles that exceed the sum of the target coal seam height and the second target height are deleted, completing the construction of the basic model of numerical simulation of horizontal segmented fully mechanized caving mining.

[0019] Preferably, generating coal seam particles of a first target height in the coal seam area to complete the construction of the coal seam model includes:

[0020] Generate an initial height of h f +5m coal seam particles, h f is the target coal seam height;

[0021] The coal seam particles are balanced by using a balance model, and after the balance, the coal seam particles with a height above the initial height are deleted and the speed of the coal seam particles is fixed;

[0022] Generating temporary particles of the target gangue layer height on the coal seam particles at a fixed speed and performing balancing;

[0023] After balancing, the velocity fixation of the coal seam particles is released and the balance is performed again;

[0024] After balancing, temporary particles exceeding the target coal seam height are deleted, and after balancing again, the construction of the coal seam model is completed.

[0025] Preferably, the speed of the coal seam particles is fixed, and gangue particles of a target gangue layer height are generated on the coal seam particles to complete the construction of the gangue layer model, including:

[0026] The speed of the coal seam particles is fixed, and gangue layer particles of a target gangue layer height are generated above the coal seam particles;

[0027] The gangue layer particles are balanced, and the gangue particles that are higher than the target gangue layer height are deleted to complete the construction of the gangue layer model.

[0028] Preferably, the coal placing procedure includes:

[0029] Set a coal placing sequence list, which is an ordered list storing coal placing port IDs;

[0030] Get the coal discharge port with id=n, and determine whether the coal discharge port is closed. If not, perform n calculations according to the minimum cycle. After the calculation is completed, traverse all particles, find all gangue particles, and determine whether gangue particles are released. If gangue particles are released, close the coal discharge port and obtain the id of the next coal discharge port; if no gangue particles are released, continue to perform n minimum cycle calculations and then determine whether gangue particles are released; if closed, obtain the id of the next coal discharge port;

[0031] The sequence list is traversed using a for loop, and when the last coal discharge port is reached and the gangue particles are discharged, the program ends.

[0032] On the other hand, the present invention provides a simulation system for implementing any of the above-mentioned horizontal segmented fully mechanized caving mining simulation methods based on rolling resistance, comprising:

[0033] Basic model building module, used to establish the basic model for numerical simulation of horizontal segmented fully mechanized caving mining;

[0034] An improvement module is used to improve the contact model of the horizontal segmented fully-mechanized top-coal caving mining numerical simulation basic model into a rolling resistance linear model, and to set the microscopic parameters and damping coefficient of the rolling resistance linear model to obtain an improved horizontal segmented fully-mechanized top-coal caving mining numerical simulation basic model;

[0035] Program setting module, used to set the coal placing program;

[0036] The simulation module is used to call the coal caving program and perform horizontal segmented fully-mechanized caving mining numerical simulation in the improved horizontal segmented fully-mechanized caving mining numerical simulation basic model.

[0037] Preferably, the basic model building module includes:

[0038] A framework construction unit is used to construct a horizontal segmented fully mechanized caving working face framework, wherein the horizontal segmented fully mechanized caving working face framework includes: a roof area, a floor area, a gangue layer area, a coal seam area, and a coal caving opening area;

[0039] A top plate and bottom plate construction unit, used to generate top plate rock particles and bottom plate rock particles in the top plate area and the bottom plate area respectively, and fix the speed of the top plate rock particles and the bottom plate rock particles to complete the construction of the top plate model and the bottom plate model;

[0040] Coal seam and gangue layer construction units are used to generate coal seam models and gangue layer models.

[0041] Preferably, the program setting module includes:

[0042] The id unit is used to set the coal discharge sequence list, which is an ordered list storing the ids of the coal discharge ports;

[0043] A loop unit is used to traverse the sequence list using a for loop, wherein the content of the for loop includes: obtaining a coal discharge port with id=n, determining whether the coal discharge port is closed, and if not, performing n calculations according to a minimum cycle, traversing all particles after the calculation, finding all gangue particles, determining whether gangue particles are discharged, and if gangue particles are discharged, closing the coal discharge port and obtaining the id of the next coal discharge port; if no gangue particles are discharged, continuing to perform n minimum cycles to determine whether gangue particles are discharged; if closed, obtaining the id of the next coal discharge port;

[0044] The end unit is used to end the program when the last coal discharge port is executed and the gangue particles are discharged.

[0045] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a method and system for simulating horizontal segmented fully-mechanized caving mining based on rolling resistance, and uses the Rolling Resistance Linear Model as a contact model to perform numerical simulation of horizontal segmented fully-mechanized caving mining, which can take into account the influence of particle shape, and its numerical simulation results are closer to the actual coal discharge situation, including: the discharge body, residual coal distribution and top coal recovery rate are closer to the actual situation. The present invention uses spherical particles as the smallest particle unit of the bulk body, which improves the calculation efficiency and solves the problem of slow calculation speed caused by using Clump or Cluster. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0047] Figure 1 A flow chart of the method provided by the present invention;

[0048] Figure 2 Establish a flow chart for the numerical simulation model of horizontal sub-level fully mechanized top-caving mining;

[0049] Figure 3 This is the flow chart of coal discharge procedure;

[0050] Figure 4 This is a system framework diagram provided by the present invention. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] The embodiment of the present invention discloses a horizontal segmented fully mechanized caving mining simulation method based on rolling resistance, such as Figure 1 As shown, including:

[0053] Establish a basic model for numerical simulation of horizontal segmented fully mechanized top-caving mining;

[0054] The contact model of the basic model for numerical simulation of horizontal segmented fully-mechanized top-coal caving mining is improved into a rolling resistance linear model (Rolling Resistance Linear Model), and the microscopic parameters and damping coefficient of the rolling resistance linear model are set to obtain the improved basic model for numerical simulation of horizontal segmented fully-mechanized top-coal caving mining.

[0055] Among them, when setting appropriate mesoscopic parameters, appropriate parameters should be selected according to the specific physical and mechanical parameters of loose top coal and gangue in the top coal caving working face. In this embodiment, the specific mesoscopic parameters can be seen in Table 1.

[0056] Table 1 Numerical simulation microscopic parameters

[0057]

[0058] Specifically, in the parameter list, the friction coefficient μ and the rolling resistance coefficient μ r The Rolling Resistance Linear Model should be used to perform the repose angle calibration test. The microscopic parameters provided in the present invention can satisfy the numerical simulation test of bulk particles with a repose angle of about 38.8°.

[0059] Set up the coal caving program and call it in the improved basic model of horizontal segmented fully-mechanized top-caving mining numerical simulation to carry out horizontal segmented fully-mechanized top-caving mining numerical simulation.

[0060] Further, such as Figure 2 As shown in the figure, a basic model for numerical simulation of horizontal segmented fully mechanized top coal caving is established, including:

[0061] Constructing a horizontal segmented fully mechanized caving working face framework, the horizontal segmented fully mechanized caving working face framework includes: a roof area, a floor area, a gangue layer area, a coal seam area, and a coal caving opening area; using wall units to construct a horizontal segmented fully mechanized caving working face framework, which includes a wall unit of the coal caving opening;

[0062] Generating roof rock particles and bottom rock particles in the roof region and the bottom region respectively, fixing the speeds of the roof rock particles and the bottom rock particles, and completing the construction of the roof model and the bottom model;

[0063] Generating coal seam particles of target coal seam height in the coal seam area to complete the construction of the coal seam model;

[0064] The speed of the coal seam particles is fixed, and gangue particles of a target gangue layer height are generated on the coal seam particles to complete the construction of the gangue layer model;

[0065] The fixed speed of the coal seam particles is released, the coal seam particles and the gangue particles are balanced, and the gangue particles that exceed the sum of the target coal seam height and the second target height are deleted, completing the construction of the basic model of numerical simulation of horizontal segmented fully mechanized caving mining.

[0066] Specifically, generating coal seam particles of a first target height in the coal seam area to complete the construction of the coal seam model includes:

[0067] Generate an initial height of h f +5m (the thickness should not be less than 2m and should not be greater than 5m) coal seam particles, h f is the target coal seam height.

[0068] The coal seam particles are balanced by using the equilibrium model. After the balance, the coal seam particles with a height above the initial height are deleted and the speed of the coal seam particles is fixed to ensure that the coal seam thickness is hf+5m and the top coal is straight. f The purpose of fixing the top coal particles within the +5m range is to ensure that the top coal particles below are not disturbed when the temporary particles are subsequently generated and balanced.

[0069] Generating temporary particles of the target gangue layer height on the coal seam particles at a fixed speed (the temporary particles here have completely the same properties as the gangue layer particles and are used to simulate the gangue layer particles) and performing balancing;

[0070] After the balance, the velocity of the coal seam particles is fixed and the balance is performed again, so that the upper temporary particles exert a load on the lower coal seam particles equal to the load of the particles with the specified thickness of the gangue layer. At this time, h f The coal seam particles at +5m will sink due to the load, and the height will no longer be h f +5m.

[0071] After balancing, temporary particles exceeding the target coal seam height are deleted, and after balancing again, the construction of the coal seam model is completed.

[0072] Furthermore, the speed of the coal seam particles is fixed, and gangue particles of a target gangue layer height are generated on the coal seam particles to complete the construction of the gangue layer model, including:

[0073] In order to prevent the coal seam below from being affected when the gangue layer particles are subsequently generated, the speed of the coal seam particles needs to be fixed before generating the gangue layer particles, and gangue layer particles of the target gangue layer height are generated above the coal seam particles;

[0074] The gangue layer particles are balanced, and the gangue particles that are higher than the target gangue layer height are deleted to complete the construction of the gangue layer model.

[0075] Furthermore, the core of the coal discharge program is an automated script program that can discharge coal in a specified order (continuous coal discharge) and close the coal discharge port when gangue particles are discharged (see gangue closing door).

[0076] The coal placement program in the present invention is implemented based on the Python interface opened in PFC, which includes calling the particle list opened in PFC, and the interface for deleting, modifying, and checking particles or particle attributes, such as Figure 3 As shown, the specific implementation steps are as follows:

[0077] Set the coal discharge sequence list, for example [5#, 6#, 7#, 8#, 9#]. The sequence list is an ordered list of the IDs of the coal discharge ports, that is, an ordered list of the IDs of the wall units of the coal discharge ports.

[0078] Get the coal discharge port with id=n (that is, delete the wall unit with id=n), determine whether the coal discharge port is closed (that is, whether the variable close is False), if not, perform n calculations in cycles (n can be adjusted according to the model scale and calculation speed, generally n is 2000), traverse all particles after n cycles, find all gangue particles, and determine whether gangue particles are released (that is, the vertical coordinate of the gangue particles is less than the vertical coordinate of the coal discharge port), if gangue particles are released, close the coal discharge port (even if close=True), and obtain the id of the next coal discharge port; if no gangue particles are released, continue to execute n cycles and then determine whether the gangue particles are released; if closed, obtain the id of the next coal discharge port;

[0079] Use a for loop to traverse the sequence list. When the last coal discharge port is reached and the gangue particles are discharged, the program ends.

[0080] In addition, if you want to implement multiple rounds of coal discharge, add another loop structure outside the coal discharge program and change the statement for judging the presence of gangue to judging the presence of top coal particles at a specified height.

[0081] In order to more intuitively illustrate the effectiveness of the present invention, the numerical simulation initial coal caving test of horizontal sub-level fully-mechanized caving mining using the widely used Linear Model and the Rolling Resistance Linear Model (hereinafter referred to as RRLinear Model) proposed by the present invention was carried out. It can be seen from the test results that the numerical simulation results of horizontal sub-level fully-mechanized caving mining using the RRlinear Model are more consistent with the experimental performance of similar simulation tests.

[0082] From the perspective of the released body morphology: the results of similar simulation tests are basically close to the BR model, and the numerical simulation results using RRLinearModel are closer to the BR model than those using Linear Model.

[0083] From the perspective of residual coal distribution and top coal recovery rate:

[0084] (1) Distribution of residual coal:

[0085] The numerical simulation results using the RRLinear Model are closer to physical experiments than the Linear Model, especially the position and shape of residual coal.

[0086] (2) Top coal recovery rate:

[0087] From the recovery rate results of two different coal discharge methods, the single-round sequential coal discharge test and the single-round end reverse coal discharge test, it can be seen that the recovery rate of the numerical simulation method using the traditional Linear Model is generally higher than the physical experimental results, while the recovery rate results of the numerical simulation method using the RRLinear Model are closer to the physical experimental data.

[0088] On the other hand, the present invention provides a simulation system for realizing any of the above-mentioned horizontal segmented fully mechanized caving mining simulation methods based on rolling resistance, such as Figure 4 As shown, including:

[0089] Basic model building module, used to establish the basic model for numerical simulation of horizontal segmented fully mechanized caving mining;

[0090] An improvement module is used to improve the contact model of the basic model of numerical simulation of horizontal sub-level fully mechanized top-coal caving mining into a rolling resistance linear model, and to set the microscopic parameters and damping coefficient of the rolling resistance linear model to obtain an improved basic model of numerical simulation of horizontal sub-level fully mechanized top-coal caving mining;

[0091] Program setting module, used to set the coal placing program;

[0092] The simulation module is used to call the coal caving program and perform horizontal segmented fully-mechanized caving mining numerical simulation in the improved horizontal segmented fully-mechanized caving mining numerical simulation basic model.

[0093] Preferably, the basic model building module includes:

[0094] A framework construction unit is used to construct a horizontal segmented fully mechanized caving working face framework, wherein the horizontal segmented fully mechanized caving working face framework includes: a roof area, a floor area, a gangue layer area, a coal seam area, and a coal caving opening area;

[0095] A top plate and bottom plate construction unit, used to generate top plate rock particles and bottom plate rock particles in the top plate area and the bottom plate area respectively, and fix the speed of the top plate rock particles and the bottom plate rock particles to complete the construction of the top plate model and the bottom plate model;

[0096] Coal seam and gangue layer construction units are used to generate coal seam models and gangue layer models.

[0097] Preferably, the program setting module includes:

[0098] The id unit is used to set the coal discharge sequence list, which is an ordered list of the ids of the coal discharge ports;

[0099] The loop unit is used to traverse the sequence list using a for loop. The content of the for loop includes: obtaining the coal discharge port with id=n, judging whether the coal discharge port is closed, if not closed, performing n calculations according to the minimum cycle, traversing all particles after the calculation, finding all gangue particles, judging whether gangue particles are discharged, and if gangue particles are discharged, closing the coal discharge port and obtaining the id of the next coal discharge port; if no gangue particles are discharged, continuing to execute n minimum cycles to judge whether gangue particles are discharged; if closed, obtaining the id of the next coal discharge port;

[0100] The end unit is used to end the program when the last coal discharge port is executed and the gangue particles are discharged.

[0101] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0102] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A horizontal sub-level fully mechanized caving mining simulation method based on rolling resistance, characterized in that: include: Establish a basic model for numerical simulation of horizontal segmented fully mechanized top-caving mining; The contact model of the horizontal sub-level fully-mechanized top-caving mining numerical simulation basic model is improved into a rolling resistance linear model, and the microscopic parameters and damping coefficient of the rolling resistance linear model are set to obtain an improved horizontal sub-level fully-mechanized top-caving mining numerical simulation basic model; The microscopic parameters include: particle type, density, particle size, relative modulus, stiffness ratio, friction coefficient, and rolling resistance coefficient; the friction coefficient and the rolling resistance coefficient are obtained by performing a repose angle calibration test using the rolling resistance linear model; Setting a coal caving program, calling the coal caving program in the improved horizontal sub-level fully-mechanized caving mining numerical simulation basic model to perform horizontal sub-level fully-mechanized caving mining numerical simulation; Establish a basic model for numerical simulation of horizontal sub-level fully mechanized top-caving mining, including: Constructing a horizontal segmented fully mechanized caving working face framework, wherein the horizontal segmented fully mechanized caving working face framework includes: a roof area, a floor area, a gangue layer area, a coal seam area, and a coal caving opening area; Generating roof rock particles and bottom rock particles in the roof region and the bottom region respectively, fixing the speeds of the roof rock particles and the bottom rock particles, and completing the construction of the roof model and the bottom model; Generating coal seam particles of target coal seam height in the coal seam area to complete the construction of the coal seam model; The speed of the coal seam particles is fixed, and gangue particles of a target gangue layer height are generated on the coal seam particles to complete the construction of the gangue layer model; The fixed speed of the coal seam particles is released, the coal seam particles and the gangue particles are balanced, and the gangue particles that exceed the sum of the target coal seam height and the second target height are deleted, completing the construction of the basic model of numerical simulation of horizontal segmented fully mechanized caving mining.

2. The horizontal sub-level fully mechanized caving mining simulation method based on rolling resistance according to claim 1 is characterized in that: Generating coal seam particles of a first target height in the coal seam area to complete the construction of the coal seam model includes: Generate an initial height of h f +5m coal seam particles, h f is the target coal seam height; The coal seam particles are balanced by using a balance model, and after the balance, the coal seam particles with a height above the initial height are deleted and the speed of the coal seam particles is fixed; Generating temporary particles of the target gangue layer height on the coal seam particles at a fixed speed and performing balancing; After balancing, the velocity fixation of the coal seam particles is released and the balance is performed again; After balancing, temporary particles exceeding the target coal seam height are deleted, and after balancing again, the construction of the coal seam model is completed.

3. The horizontal sub-level fully mechanized caving mining simulation method based on rolling resistance according to claim 2 is characterized in that: The speed of the coal seam particles is fixed, and gangue particles of a target gangue layer height are generated on the coal seam particles to complete the construction of the gangue layer model, including: The speed of the coal seam particles is fixed, and gangue layer particles of a target gangue layer height are generated above the coal seam particles; The gangue layer particles are balanced, and the gangue particles that are higher than the target gangue layer height are deleted to complete the construction of the gangue layer model.

4. The horizontal sub-level fully mechanized caving mining simulation method based on rolling resistance according to claim 1 is characterized in that: The coal placing procedure includes: Set a coal placing sequence list, which is an ordered list storing coal placing port IDs; Get the coal discharge port with id=n, and determine whether the coal discharge port is closed. If not, perform n calculations according to the minimum cycle. After the calculation is completed, traverse all particles, find all gangue particles, and determine whether gangue particles are released. If gangue particles are released, close the coal discharge port and obtain the id of the next coal discharge port; if no gangue particles are released, continue to perform n minimum cycle calculations and then determine whether gangue particles are released; if closed, obtain the id of the next coal discharge port; The sequence list is traversed using a for loop, and when the last coal discharge port is reached and the gangue particles are discharged, the program ends.

5. A horizontal sub-level fully mechanized top-caving mining simulation system based on rolling resistance, using a horizontal sub-level fully mechanized top-caving mining simulation method based on rolling resistance according to any one of claims 1 to 4, characterized in that: include: Basic model building module, used to establish the basic model for numerical simulation of horizontal segmented fully mechanized caving mining; An improvement module is used to improve the contact model of the horizontal segmented fully-mechanized top-coal caving mining numerical simulation basic model into a rolling resistance linear model, and to set the microscopic parameters and damping coefficient of the rolling resistance linear model to obtain an improved horizontal segmented fully-mechanized top-coal caving mining numerical simulation basic model; The microscopic parameters include: particle type, density, particle size, relative modulus, stiffness ratio, friction coefficient, and rolling resistance coefficient; the friction coefficient and rolling resistance coefficient are obtained by performing a repose angle calibration test using the rolling resistance linear model; Program setting module, used to set the coal placing program; A simulation module, used for calling the coal caving program and performing horizontal sub-level fully-mechanized caving mining numerical simulation in the improved horizontal sub-level fully-mechanized caving mining numerical simulation basic model; The basic model building module includes: A framework construction unit is used to construct a horizontal segmented fully mechanized caving working face framework, wherein the horizontal segmented fully mechanized caving working face framework includes: a roof area, a floor area, a gangue layer area, a coal seam area, and a coal caving opening area; A top plate and bottom plate construction unit, used to generate top plate rock particles and bottom plate rock particles in the top plate area and the bottom plate area respectively, and fix the speed of the top plate rock particles and the bottom plate rock particles to complete the construction of the top plate model and the bottom plate model; Coal seam and gangue layer construction units are used to generate coal seam models and gangue layer models.

6. The horizontal sub-level fully mechanized caving mining simulation system based on rolling resistance according to claim 5 is characterized in that: The program settings module includes: The id unit is used to set the coal discharge sequence list, which is an ordered list storing the ids of the coal discharge ports; A loop unit is used to traverse the sequence list using a for loop, wherein the content of the for loop includes: obtaining a coal discharge port with id=n, determining whether the coal discharge port is closed, and if not, performing n calculations according to a minimum cycle, traversing all particles after the calculations are completed, finding all gangue particles, determining whether gangue particles are discharged, and if gangue particles are discharged, closing the coal discharge port and obtaining the id of the next coal discharge port; if no gangue particles are discharged, continuing to perform n minimum cycle calculations to determine whether gangue particles are discharged; if closed, obtaining the id of the next coal discharge port; The end unit is used to end the program when the last coal discharge port is executed and the gangue particles are discharged.

Images