Refined three-dimensional characterization method and device for porosity of goaf

Abstract

The invention provides a goaf porosity refined three-dimensional characterization method and device, and the method comprises the steps: building a working face coal seam mining model based on the physical and mechanical parameters of coal and rock mass and a working face rock stratum geological map; a step-by-step excavation method is adopted to operate the working face coal seam mining models in different periods until convergence is achieved, and a three-dimensional model which operates convergence after excavation is obtained; slicing the three-dimensional model which is converged after excavation to obtain a plurality of model slices; performing gray processing on the plurality of model slices to obtain a model slice image stack after gray adjustment; performing vectorization processing and threshold segmentation processing on the model slice image stack to obtain a goaf overlying strata mining three-dimensional fracture network model; performing circular cutting treatment on the goaf overburden mining three-dimensional fracture network model to obtain a plurality of unit cutting models; calculating the porosity of each unit cutting model; the problems that the porosity of the goaf cannot be actually measured, and the porosity theoretical formula cannot accurately represent the porosity of the specific mine goaf are solved.

Description

Technical Field

[0001] The present application relates to the field of mining safety technology, and in particular to a method and device for fine-grained three-dimensional characterization of porosity in goaf areas. Background Art

[0002] In the field of disaster prevention and control of goaf areas in coal mines, the study of goaf flow field has always been the focus. Goaf is an important part of coal mine disasters. Goaf fire prevention and control and goaf gas extraction are inseparable from the study of goaf flow field. Limited by the special geographical location of goaf, the study of goaf flow field is mainly carried out by assuming the goaf as a porous medium in seepage mechanics and applying numerical simulation methods.

[0003] Porosity and permeability are important parameters that affect the gas flow law in goaf. Nowadays, scholars at home and abroad mainly characterize the porosity of goaf through theoretical analysis, similar material simulation and other means. However, the above methods are greatly affected by human factors and cannot reflect the actual situation of a specific working face. There is a problem that the porosity of goaf cannot be accurately extracted. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0005] To this end, the first purpose of this application is to propose a method for refined three-dimensional characterization of the porosity of the goaf, so as to achieve refined three-dimensional characterization of the porosity of the goaf and solve the problem in related technologies that the porosity of the goaf cannot be accurately extracted.

[0006] The second purpose of the present application is to propose a device for fine-grained three-dimensional characterization of the porosity of goaf areas.

[0007] The third objective of the present application is to provide an electronic device.

[0008] A fourth objective of the present application is to provide a computer-readable storage medium.

[0009] A fifth object of the present application is to provide a computer program product.

[0010] To achieve the above-mentioned purpose, the first embodiment of the present application proposes a method for fine-grained three-dimensional characterization of porosity in goaf areas, comprising:

[0011] Based on the physical and mechanical parameters of the coal rock mass and the geological map of the rock formations at the working face, a coal seam mining model for the working face is established; and the coal seam mining model for the working face is run at different times by a step-by-step excavation method until convergence, so as to obtain a three-dimensional model corresponding to different excavation step distances and convergence after excavation;

[0012] Slicing the three-dimensional model that converges after excavation to obtain a plurality of model slices; and grayscale processing the plurality of model slices to obtain a grayscale-adjusted model slice image stack;

[0013] Performing vectorization and threshold segmentation processing on the model slice image stack by three-dimensional visualization processing software to obtain a three-dimensional fracture network model of overburden mining in the goaf area;

[0014] The three-dimensional fracture network model of the overburden mining in the goaf is subjected to cyclic cutting processing to obtain a plurality of unit cutting models; and the porosity of each unit cutting model in the plurality of unit cutting models is calculated to obtain a refined three-dimensional representation of the porosity of the goaf.

[0015] In some implementations, the step of establishing a coal seam mining model for a working face based on the physical and mechanical parameters of the coal and rock mass and the geological map of the rock formations at the working face comprises:

[0016] Obtaining physical and mechanical parameters of coal and rock mass obtained by measuring physical and mechanical parameters of coal seam roof and floor rock strata;

[0017] Based on the physical and mechanical parameters of coal rock mass and geological map of rock strata at working face, a coal seam mining model of working face was established by discrete element numerical simulation software.

[0018] In some implementations, the step-by-step excavation method is used to run the coal seam mining model of the working face at different periods until convergence, and obtains a three-dimensional model corresponding to different excavation steps and convergence after excavation; including:

[0019] Determine the simulation parameters of the step-by-step excavation process according to the actual mining conditions of the working face;

[0020] The coal seam mining model of the working face at different periods is run until convergence by adopting a step-by-step excavation method, and a three-dimensional model of post-excavation operation convergence corresponding to different excavation step distances is obtained.

[0021] In some implementations, the slicing of the three-dimensional model after the excavation convergence to obtain a plurality of model slices includes:

[0022] Adjust the viewing angle of the three-dimensional model that converges after excavation and turn off the perspective function to ensure that the size and position of each slice are consistent;

[0023] The fish language built into the discrete element numerical simulation software 3DEC is used to slice the three-dimensional model after the perspective adjustment based on the direction of the model to obtain multiple model slices.

[0024] In some implementations, grayscale processing is performed on the plurality of model slices to obtain a grayscale-adjusted model slice image stack; comprising:

[0025] Cutting off invalid areas of the plurality of model slices to obtain a plurality of cut model slices that are all valid areas of the model;

[0026] Grayscale adjustment is performed on the cropped multiple model slices to obtain a grayscale-adjusted model slice image stack.

[0027] In some implementations, the three-dimensional visualization processing software is used to perform vectorization and threshold segmentation processing on the model slice image stack to obtain a three-dimensional fracture network model of overburden mining in the goaf area; including:

[0028] Performing vectorization processing on the model slice image stack by three-dimensional visualization image processing software to obtain a vectorized model slice image stack;

[0029] Image threshold segmentation is performed on the vectorized model slice image stack to obtain a three-dimensional fracture network model of overburden mining in the goaf area.

[0030] In some implementations, the three-dimensional fracture network model of the overburden mining in the goaf is subjected to cyclic cutting processing to obtain a plurality of unit cutting models; and the porosity of each unit cutting model in the plurality of unit cutting models is calculated; including:

[0031] The Extract Subvolume module of the Avizo software is called through a script loop to perform cyclic cutting processing on the three-dimensional fracture network model of the overburden mining in the goaf to obtain multiple unit cutting models of preset sizes; and the Volume Fraction module of the Avizo software is called to calculate the porosity of the unit cutting models of the multiple preset sizes, and the calculated porosity is stored in the project file.

[0032] In some implementations, after calculating the porosity of each unit cutting model in the plurality of unit cutting models, the method further includes:

[0033] The project file including porosity is read through Python command to obtain the porosity of the goaf area of ​​the unit cutting model.

[0034] To achieve the above-mentioned purpose, the second embodiment of the present application proposes a device for fine three-dimensional characterization of porosity in goaf, comprising:

[0035] A model building module is used to establish a coal seam mining model for a working face based on the physical and mechanical parameters of the coal rock mass and the geological map of the rock formations of the working face; and to run the coal seam mining model for the working face at different periods by using a step-by-step excavation method until convergence, to obtain a three-dimensional model corresponding to different excavation step distances and running convergence after excavation;

[0036] A model processing module is used to slice the three-dimensional model after the excavation and convergence to obtain a plurality of model slices; and grayscale process the plurality of model slices to obtain a grayscale-adjusted model slice image stack;

[0037] A fracture identification module is used to perform vectorization and threshold segmentation processing on the model slice image stack through three-dimensional visualization processing software to obtain a three-dimensional fracture network model of overburden mining in the goaf area;

[0038] The parameter acquisition module is used to perform cyclic cutting processing on the three-dimensional fracture network model of the overburden mining in the goaf area to obtain multiple unit cutting models; and calculate the porosity of each unit cutting model in the multiple unit cutting models to obtain a refined three-dimensional representation of the porosity of the goaf area.

[0039] In some implementations, the model building module is used to:

[0040] Obtaining physical and mechanical parameters of coal and rock mass obtained by measuring physical and mechanical parameters of coal seam roof and floor rock strata;

[0041] Based on the physical and mechanical parameters of coal rock mass and geological map of rock strata at working face, a coal seam mining model of working face was established by discrete element numerical simulation software.

[0042] In some implementations, the model building module is used to:

[0043] Determine the simulation parameters of the step-by-step excavation process according to the actual mining conditions of the working face;

[0044] The coal seam mining model of the working face at different periods is run until convergence by adopting a step-by-step excavation method, and a three-dimensional model of post-excavation operation convergence corresponding to different excavation step distances is obtained.

[0045] In some implementations, the model processing module, when slicing the three-dimensional model that converges after excavation to obtain a plurality of model slices, is used to:

[0046] Adjust the viewing angle of the three-dimensional model that converges after excavation and turn off the perspective function to ensure that the size and position of each slice are consistent;

[0047] The fish language built into the discrete element numerical simulation software 3DEC is used to slice the three-dimensional model after the perspective adjustment based on the direction of the model to obtain multiple model slices.

[0048] In some implementations, when the model processing module performs grayscale processing on the plurality of model slices to obtain a grayscale-adjusted model slice image stack, it is configured to:

[0049] Cutting off invalid areas of the plurality of model slices to obtain a plurality of cut model slices that are all valid areas of the model;

[0050] Grayscale adjustment is performed on the cropped multiple model slices to obtain a grayscale-adjusted model slice image stack.

[0051] In some implementations, the crack identification module is specifically configured to:

[0052] Performing vectorization processing on the model slice image stack by three-dimensional visualization image processing software to obtain a vectorized model slice image stack;

[0053] Image threshold segmentation is performed on the vectorized model slice image stack to obtain a three-dimensional fracture network model of overburden mining in the goaf area.

[0054] In some implementations, the parameter acquisition module is specifically used to:

[0055] The Extract Subvolume module of the Avizo software is called through a script loop to perform cyclic cutting processing on the three-dimensional fracture network model of the overburden mining in the goaf to obtain multiple unit cutting models of preset sizes; and the Volume Fraction module of the Avizo software is called to calculate the porosity of the unit cutting models of the multiple preset sizes, and the calculated porosity is stored in the project file.

[0056] In some implementations, the parameter acquisition module is further used to:

[0057] The project file including porosity is read through Python command to obtain the porosity of the goaf area of ​​the unit cutting model.

[0058] To achieve the above-mentioned purpose, the third aspect embodiment of the present application proposes an electronic device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method described in the first aspect.

[0059] To achieve the above-mentioned purpose, the fourth aspect of the present application proposes a computer-readable storage medium, in which computer-readable storage medium is stored computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the method described in the first aspect.

[0060] To achieve the above-mentioned purpose, the fifth aspect of the present application proposes a computer program product, including a computer program, which implements the method described in the first aspect when executed by a processor.

[0061] The present application provides a method and device for fine-grained three-dimensional characterization of the porosity of the goaf, constructs a coal seam mining model of the working face, and adopts a step-by-step excavation method to simulate the actual excavation process of the working face, so as to obtain a three-dimensional model of post-excavation convergence corresponding to different excavation step distances, that is, to obtain the internal collapse morphology of the model with different excavation step distances and the spatiotemporal evolution characteristics of the distribution of mining fractures; the three-dimensional model of post-excavation convergence is sliced, grayed, and thresholded to obtain a three-dimensional fracture network model of the overburden mining in the goaf, and the three-dimensional fracture network model of the overburden mining in the goaf is cut to obtain multiple unit cutting models. And calculate the porosity of each unit cutting model to obtain a refined three-dimensional representation of the porosity of the goaf; through the present invention, on the basis of the quantitative characterization of the macro and micro parameters of the coal rock mass, it is possible to quickly realize the model construction of the real fracture network in the mining process and the three-dimensional representation of the porosity of the goaf; it solves the problem that the porosity of the goaf cannot be measured on site and the porosity theoretical formula cannot accurately represent the porosity of the goaf of a specific mine, and realizes the refined representation of the three-dimensional goaf porosity, which can meet the needs of accurate characterization of the porosity of the goaf in the fields of goaf pressure relief gas extraction, goaf coal spontaneous combustion prevention and control, etc.

[0062] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0064] Figure 1 A schematic diagram of a process for a refined three-dimensional characterization method of porosity in a goaf provided in an embodiment of the present application;

[0065] Figure 2 An example diagram of a working face coal seam mining model provided in an embodiment of the present application;

[0066] Figure 3 An example diagram of a model slice provided in an embodiment of the present application;

[0067] Figure 4 An example diagram of a model slice image stack after vectorization processing provided in an embodiment of the present application;

[0068] Figure 5 An example diagram of a three-dimensional fracture network model of overburden mining in a goaf area provided in an embodiment of the present application;

[0069] Figure 6 An example diagram of a three-dimensional distribution of porosity in a goaf provided in an embodiment of the present application;

[0070] Figure 7 A block diagram of a device for fine three-dimensional characterization of porosity in a goaf provided in an embodiment of the present application;

[0071] Figure 8 A block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0072] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0073] The following describes the method, device and equipment for fine-grained three-dimensional characterization of porosity in goaf areas according to an embodiment of the present application with reference to the accompanying drawings.

[0074] Figure 1 A schematic flow chart of a method for refined three-dimensional characterization of porosity in goaf provided in an embodiment of the present application.

[0075] It should be noted that the executor of the method for fine-grained three-dimensional characterization of the porosity of the goaf in the embodiment of the present application is the device for fine-grained three-dimensional characterization of the porosity of the goaf in the embodiment of the present application. The device for fine-grained three-dimensional characterization of the porosity of the goaf can be configured in an electronic device so that the electronic device can perform the function of fine-grained three-dimensional characterization of the porosity of the goaf.

[0076] like Figure 1 As shown, the refined three-dimensional characterization method for the porosity of the goaf includes the following steps:

[0077] Step 101, based on the physical and mechanical parameters of the coal rock mass and the geological map of the rock formations of the working face, a coal seam mining model of the working face is established; and the coal seam mining model of the working face at different periods is run until convergence using a step-by-step excavation method to obtain a three-dimensional model of convergence after excavation corresponding to different excavation step distances.

[0078] As an implementation method, a method for establishing a coal seam mining model for a working face is provided; the method includes: obtaining physical and mechanical parameters of the coal rock mass obtained by measuring the physical and mechanical parameters of the coal seam roof and floor strata; and establishing a coal seam mining model for a working face through discrete element numerical simulation software based on the physical and mechanical parameters of the coal rock mass and the geological map of the rock strata of the working face.

[0079] Exemplarily, the geological map of the rock strata at the working face is a comprehensive columnar diagram of the rock strata at the top and bottom plates of the working face.

[0080] As an implementation method, the physical and mechanical parameters of the coal seam roof and floor rock strata are measured to obtain the physical and mechanical parameters of the coal rock mass. The physical and mechanical parameters of the coal rock mass may include but are not limited to: bulk density, elastic model, Poisson's ratio, cohesion, internal friction angle, tensile strength and other parameters.

[0081] For example, the discrete element numerical simulation software used in this scheme is 3DEC software. Based on the comprehensive columnar diagram of the top and bottom rock layers of the working face and the physical and mechanical parameters of the coal and rock mass, 3DEC is used to establish the coal seam mining model of the working face, such as Figure 2 shown.

[0082] As an implementation method, a method for obtaining a three-dimensional model of convergence after excavation is provided; comprising: according to the actual mining conditions of the working face, using a step-by-step excavation method to run the coal seam mining model of the working face in different periods until convergence, and obtaining a three-dimensional model of convergence after excavation corresponding to different excavation step distances.

[0083] That is to say, the step-by-step excavation process is simulated according to the actual mining conditions of the working face, and the coal seam mining models of the working face at different periods are run until convergence to obtain the roof overburden structure at different excavation step distances.

[0084] For example, a 360-meter working face coal seam mining model is first established, that is, a large model with a working face length of 360 meters, and then excavation is carried out with a step distance of 30 meters, so that a developed working face coal seam mining model can be obtained when excavating 30 meters; similarly, the working face coal seam mining model after excavating 60 meters, 90 meters, and 120 meters can be obtained, and so on, the corresponding working face coal seam mining models under different development step distances can be obtained. After each excavation step, for example, after excavating 30 meters, the corresponding developed working face coal seam mining model after excavating 30 meters is run until convergence; then excavate the next 30 meters, run convergence again, excavate the next 30 meters, and so on, and obtain the three-dimensional model of convergence after excavation corresponding to different excavation step distances.

[0085] Step 102, slicing the three-dimensional model after excavation and convergence to obtain a plurality of model slices; and grayscale processing the plurality of model slices to obtain a grayscale-adjusted model slice image stack.

[0086] As an implementation method, a method for obtaining multiple model slices includes: adjusting the viewing angle of a three-dimensional model that converges after excavation and turning off the perspective function to ensure that the size and position of each slice are consistent; slicing the three-dimensional model after the viewing angle is adjusted based on the model's direction through the built-in fish language of discrete element numerical simulation software 3DEC to obtain multiple model slices.

[0087] For example, based on the converged 3D model after excavation, the model viewing angle is adjusted and perspective is turned off to ensure that the size and position of each slice are consistent. The model is sliced ​​in the direction of the model through the built-in fish language of 3DEC and exported in batches with a slicing accuracy of 0.1m.

[0088] As an implementation method, a method for obtaining a grayscale-adjusted model slice image stack includes: cropping invalid areas of multiple model slices to obtain multiple cropped model slices that are all valid model areas; grayscale-adjusting the cropped multiple model slices to obtain a grayscale-adjusted model slice image stack.

[0089] It can be understood that since the image exported by the 3DEC software is a window page, it contains invalid areas. Therefore, the slices are cropped through image processing software to ensure that the entire slice is a valid model area.

[0090] As an implementation method, the cropped model slices are imported into Image-J software for grayscale adjustment so that the image retains only two colors: black and white. Among them, black is the rock matrix area, and white is the fracture area. The model slices are as follows Figure 3 Use the Process-Batch-Macro option to record the operation code, use the operation code to batch process the slices, and export them as vector images.

[0091] Step 103, using 3D visualization processing software to perform vectorization and threshold segmentation processing on the model slice image stack, to obtain a 3D fracture network model of the overburden in the goaf.

[0092] In some embodiments, a method for obtaining a three-dimensional fracture network model of overburden mining in a goaf area comprises: vectorizing a model slice image stack through three-dimensional visualization image processing software to obtain a vectorized model slice image stack; performing image threshold segmentation on the vectorized model slice image stack to obtain a three-dimensional fracture network model of overburden mining in the goaf area.

[0093] As an implementation method, the grayscale adjusted model slice image is vectorized by using the 3D visualization image processing software Avizo, and then the image threshold segmentation is performed using the Interactive Thresholding module to extract the crack part in the image, that is, the 3D crack network model of the overburden mining in the goaf area, as shown in Figure 2. Figure 5 As shown in the figure, the VolumeRendering module is used to display the morphology and distribution characteristics of the crack part. The vector image obtained in the previous step is imported into the Avizo software for vectorization processing, and the following is obtained: Figure 4 Image stack of model slices after vectorization shown.

[0094] The above steps are combined with image processing technology, real investigation of the porosity of the goaf at local point locations and 3DEC simulation to obtain the spatiotemporal distribution results of mining fractures, extract the rock matrix and fracture space of the two-dimensional image, and on the basis of three-dimensional reconstruction technology, extract the distribution information of the goaf fracture network to establish a three-dimensional fracture network model of the overburden mining in the goaf.

[0095] Step 104, cyclically cutting the three-dimensional fracture network model of the overburden in the goaf to obtain a plurality of unit cutting models; and calculating the porosity of each unit cutting model in the plurality of unit cutting models to obtain a refined three-dimensional representation of the porosity of the goaf.

[0096] As an implementation method, according to the preset cutting size, the ExtractSubvolume module of the Avizo software is called through a script loop to start from the origin of the three-dimensional fracture network model of the overburden mining in the goaf, and the three-dimensional fracture network model of the overburden mining in the goaf is cyclically cut to obtain multiple unit cutting models with preset cutting sizes; and the Volume Fraction module of the Avizo software is called to calculate the porosity of the unit cutting models with multiple preset sizes, and the calculated porosity is stored in the project file.

[0097] As an implementation method, the Extract Subvolume module of the Avizo software is used to extract a 10*10*10m cube model area at the origin of the three-dimensional fracture network model of the overburden mining in the goaf, and the porosity of the area is calculated by the Volume Fraction module, and the project file is saved; the project file is opened as a text document, and the script command is modified to a loop command so that it can automatically loop cut the three-dimensional fracture network model of the overburden mining in the goaf, and output the engineering file containing the porosity data of the corresponding small model (i.e., the unit cutting model) until the cutting of the three-dimensional fracture network model of the overburden mining in the goaf is completed.

[0098] In some embodiments, after calculating the porosity of each unit cutting model in a plurality of unit cutting models, the method includes: reading a project file including the porosity through a Python command to obtain the porosity of the goaf of the unit cutting model.

[0099] It can be understood that each unit cutting model has one porosity, and multiple unit cutting models have multiple porosities. The three-dimensional distribution of porosity in the goaf corresponding to the three-dimensional fracture network model of the overburden mining is as follows: Figure 6 shown.

[0100] As an implementation method, the engineering file containing porosity data is read through the Python command to obtain the porosity data and output it in batches; based on the porosity value, a three-dimensional porosity distribution model of the goaf is finally constructed. Constructing a three-dimensional porosity distribution model of the goaf is only a manifestation of the three-dimensional distribution of the porosity of the goaf.

[0101] The method for fine-grained three-dimensional characterization of the porosity of the goaf in the embodiment of the present application constructs a coal seam mining model of the working face, and adopts a step-by-step excavation method to simulate the actual excavation process of the working face, so as to obtain a three-dimensional model of post-excavation convergence corresponding to different excavation step distances, that is, to obtain the internal collapse morphology of the model with different excavation step distances and the spatiotemporal evolution characteristics of the distribution of mining fractures; the three-dimensional model of post-excavation convergence is sliced, grayed, and thresholded to obtain a three-dimensional fracture network model of the overburden mining in the goaf, and the three-dimensional fracture network model of the overburden mining in the goaf is cut to obtain multiple unit cutting models and The porosity of each unit cutting model is calculated to obtain a refined three-dimensional representation of the porosity of the goaf. The present invention can quickly realize the model construction of the real fracture network in the mining process and the three-dimensional representation of the porosity of the goaf on the basis of the quantitative representation of the macro and micro parameters of the coal rock mass. It solves the problem that the porosity of the goaf cannot be measured on site and the porosity theoretical formula cannot accurately represent the porosity of the goaf of a specific mine, and realizes the refined representation of the three-dimensional porosity of the goaf, which can meet the needs of accurate representation of the porosity of the goaf in the fields of goaf pressure relief gas extraction, goaf spontaneous combustion prevention and control, etc.

[0102] In order to implement the above-mentioned embodiment, the present application also proposes a device for fine-grained three-dimensional characterization of the porosity of goaf areas. Figure 7 This is a block diagram of a device for finely characterizing the porosity of a goaf provided in an embodiment of the present application. Figure 7 As shown, the device for fine three-dimensional characterization of porosity of goaf may include: a model building module 701 , a model processing module 702 , a crack identification module 703 and a parameter acquisition module 704 .

[0103] The model building module 701 is used to establish a coal seam mining model for the working face based on the physical and mechanical parameters of the coal rock mass and the geological map of the rock formation of the working face; and to run the coal seam mining model of the working face at different periods by using a step-by-step excavation method until convergence, and obtain a three-dimensional model corresponding to different excavation step distances and running convergence after excavation;

[0104] The model processing module 702 is used to slice the three-dimensional model after excavation and convergence to obtain multiple model slices; and grayscale process the multiple model slices to obtain a grayscale adjusted model slice image stack;

[0105] The fracture identification module 703 is used to perform vectorization and threshold segmentation processing on the model slice image stack through three-dimensional visualization processing software to obtain a three-dimensional fracture network model of the overburden mining in the goaf area;

[0106] The parameter acquisition module 704 is used to perform cyclic cutting processing on the three-dimensional fracture network model of the overburden mining in the goaf area to obtain multiple unit cutting models; and calculate the porosity of each unit cutting model in the multiple unit cutting models to obtain a refined three-dimensional representation of the porosity of the goaf area.

[0107] Further, in a possible implementation of the embodiment of the present application, when the model building module 701 establishes the coal seam mining model of the working face based on the physical and mechanical parameters of the coal and rock mass and the geological map of the rock formation of the working face, it is used to:

[0108] Obtaining physical and mechanical parameters of coal and rock mass obtained by measuring physical and mechanical parameters of coal seam roof and floor rock strata;

[0109] Based on the physical and mechanical parameters of coal rock mass and geological map of rock strata at working face, a coal seam mining model of working face was established by discrete element numerical simulation software.

[0110] Further, in a possible implementation of the embodiment of the present application, the model building module 701 runs the coal seam mining model of the working face in different periods until convergence by adopting the step-by-step excavation method to obtain the converged three-dimensional model after excavation corresponding to different excavation step distances; it is used to:

[0111] Determine the simulation parameters of the step-by-step excavation process according to the actual mining conditions of the working face;

[0112] The step-by-step excavation method is used to run the coal seam mining model of the working face at different periods until convergence, and a three-dimensional model of post-excavation convergence corresponding to different excavation step distances is obtained.

[0113] Further, in a possible implementation of the embodiment of the present application, when the model processing module 702 performs slicing processing on the three-dimensional model that converges after excavation to obtain multiple model slices, it is used to:

[0114] Adjust the viewing angle of the 3D model after excavation and turn off the perspective function to ensure that the size and position of each slice are consistent;

[0115] The fish language built into the discrete element numerical simulation software 3DEC is used to slice the three-dimensional model after the perspective adjustment based on the direction of the model to obtain multiple model slices.

[0116] Furthermore, in a possible implementation of the embodiment of the present application, when the model processing module 702 performs grayscale processing on a plurality of model slices to obtain a grayscale-adjusted model slice image stack, it is configured to:

[0117] Crop out invalid areas of multiple model slices to obtain multiple model slices that are all valid areas of the model;

[0118] Grayscale adjustment is performed on the cropped multiple model slices to obtain a grayscale-adjusted model slice image stack.

[0119] Furthermore, in a possible implementation of the embodiment of the present application, the crack identification module 703 is specifically configured to:

[0120] Performing vector processing on the model slice image stack by using three-dimensional visualization image processing software to obtain a vectorized model slice image stack;

[0121] The vectorized model slice image stack is segmented by image threshold to obtain the three-dimensional fracture network model of the overburden in the goaf.

[0122] Furthermore, in a possible implementation of the embodiment of the present application, the parameter acquisition module 704 is specifically configured to:

[0123] The Extract Subvolume module of Avizo software is called through a script loop to perform cyclic cutting processing on the three-dimensional fracture network model of the overburden mining in the goaf to obtain multiple unit cutting models of preset sizes; and the Volume Fraction module of Avizo software is called to calculate the porosity of multiple unit cutting models of preset sizes, and the calculated porosity is stored in the project file.

[0124] Furthermore, in a possible implementation of the embodiment of the present application, the parameter acquisition module 704 is further configured to:

[0125] The project file including porosity is read through Python command to obtain the porosity of the goaf area of ​​the unit cutting model.

[0126] It should be noted that the aforementioned explanation of the embodiment of the method for fine-grained three-dimensional characterization of the porosity of goaf is also applicable to the device for fine-grained three-dimensional characterization of the porosity of goaf of this embodiment, and will not be repeated here.

[0127] In order to implement the above embodiment, the present application also proposes an electronic device. Figure 8 , Figure 8 is a block diagram of an electronic device provided in an embodiment of the present application. Figure 8 As shown, the electronic device 800 includes: a processor 801, and a memory 802 communicatively connected to the processor 801; the memory 802 stores computer-executable instructions; the processor 801 executes the computer-executable instructions stored in the memory to implement the method provided in the aforementioned embodiment.

[0128] In order to implement the above embodiments, the present application also proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the methods provided by the above embodiments.

[0129] In order to implement the above embodiments, the present application also proposes a computer program product, including a computer program, which implements the methods provided by the above embodiments when executed by a processor.

[0130] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means 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 application. 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. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0131] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0132] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0133] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0134] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0135] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0136] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0137] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A refined three-dimensional characterization method for porosity of goaf, characterized in that: The following steps are involved: Based on the physical and mechanical parameters of the coal rock mass and the geological map of the rock formations at the working face, a coal seam mining model for the working face is established; and the coal seam mining model for the working face is run at different times by a step-by-step excavation method until convergence, so as to obtain a three-dimensional model corresponding to different excavation step distances and convergence after excavation; Slicing the three-dimensional model that converges after excavation to obtain a plurality of model slices; and grayscale processing the plurality of model slices to obtain a grayscale-adjusted model slice image stack; Performing vectorization and threshold segmentation processing on the model slice image stack by three-dimensional visualization processing software to obtain a three-dimensional fracture network model of overburden mining in the goaf area; The three-dimensional fracture network model of the overburden mining in the goaf is subjected to cyclic cutting processing to obtain a plurality of unit cutting models; and the porosity of each unit cutting model in the plurality of unit cutting models is calculated to obtain a refined three-dimensional representation of the porosity of the goaf.

2. The method according to claim 1, characterized in that The method of establishing a coal seam mining model for a working face based on the physical and mechanical parameters of the coal rock mass and the geological map of the rock formations at the working face comprises: Obtaining physical and mechanical parameters of coal and rock mass obtained by measuring physical and mechanical parameters of coal seam roof and floor rock strata; Based on the physical and mechanical parameters of coal rock mass and geological map of rock strata at working face, a coal seam mining model of working face was established by discrete element numerical simulation software.

3. The method according to claim 1, characterized in that The step-by-step excavation method is used to run the coal seam mining model of the working face at different periods until convergence, and obtains a three-dimensional model corresponding to different excavation steps after excavation and convergence; including: Determine the simulation parameters of the step-by-step excavation process according to the actual mining conditions of the working face; Based on the simulation parameters of the step-by-step excavation process, the coal seam mining model of the working face is run at different periods until convergence, and a three-dimensional model of post-excavation operation convergence corresponding to different excavation step distances is obtained.

4. The method according to claim 1, characterized in that The slicing process of the three-dimensional model after the excavation converges to obtain a plurality of model slices comprises: Adjust the viewing angle of the three-dimensional model that converges after excavation and turn off the perspective function to ensure that the size and position of each slice are consistent; The fish language built into the discrete element numerical simulation software 3DEC is used to slice the three-dimensional model after the perspective adjustment based on the direction of the model to obtain multiple model slices.

5. The method according to claim 1, characterized in that The grayscale processing of the plurality of model slices to obtain a grayscale-adjusted model slice image stack comprises: Cutting off invalid areas of the plurality of model slices to obtain a plurality of cut model slices that are all valid areas of the model; Grayscale adjustment is performed on the cropped multiple model slices to obtain a grayscale-adjusted model slice image stack.

6. The method according to claim 1, characterized in that The three-dimensional visualization processing software is used to perform vectorization processing and threshold segmentation processing on the model slice image stack to obtain a three-dimensional fracture network model of the overburden mining in the goaf area; including: Performing vectorization processing on the model slice image stack by three-dimensional visualization image processing software to obtain a vectorized model slice image stack; The vectorized model slice image stack is subjected to image threshold segmentation to obtain a three-dimensional fracture network model of overburden mining in the goaf area.

7. The method according to claim 1, characterized in that The method of performing cyclic cutting processing on the three-dimensional fracture network model of the overburden mining in the goaf area to obtain a plurality of unit cutting models; and calculating the porosity of each unit cutting model in the plurality of unit cutting models; comprises: The Extract Subvolume module of the Avizo software is called through a script loop to perform cyclic cutting processing on the three-dimensional fracture network model of the overburden mining in the goaf to obtain multiple unit cutting models of preset sizes; and the Volume Fraction module of the Avizo software is called to calculate the porosity of the unit cutting models of the multiple preset sizes, and the calculated porosity is stored in the project file.

8. The method according to claim 7, characterized in that After calculating the porosity of each unit cutting model in the plurality of unit cutting models, the method further comprises: The project file including porosity is read through Python command to obtain the porosity of the goaf area of ​​the unit cutting model.

9. A device for finely characterizing the porosity of a goaf area in three dimensions, characterized in that: include: Model building module, used to establish the coal seam mining model of the working face based on the physical and mechanical parameters of the coal rock mass and the geological map of the rock formation of the working face; The coal seam mining model of the working face at different periods is run by using a step-by-step excavation method until convergence, and a three-dimensional model corresponding to different excavation step distances and convergence after excavation is obtained; A model processing module is used to slice the three-dimensional model after the excavation and convergence to obtain a plurality of model slices; and grayscale process the plurality of model slices to obtain a grayscale-adjusted model slice image stack; A fracture identification module is used to perform vectorization and threshold segmentation processing on the model slice image stack through three-dimensional visualization processing software to obtain a three-dimensional fracture network model of overburden mining in the goaf area; The parameter acquisition module is used to perform cyclic cutting processing on the three-dimensional fracture network model of the overburden mining in the goaf area to obtain multiple unit cutting models; and calculate the porosity of each unit cutting model in the multiple unit cutting models to obtain a refined three-dimensional representation of the porosity of the goaf area.

10. An electronic device, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 8.

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