Coal rock numerical model reconstruction method considering native joint structure distribution

Abstract

The invention discloses a coal rock numerical model reconstruction method considering native joint structure distribution, and relates to the technical field of rock mass engineering.The method comprises the steps that joint coal rock images are collected, the spacing distances and the number of bedding, face cleats and end cleats are counted, and probability distribution functions of the bedding, the face cleats and the end cleats are fitted; according to the statistical distribution rule, constructing a coal rock single-layer cleat structure network model, and constructing a plurality of two-dimensional random cleat structure network models; stacking the plurality of two-dimensional random cleat structure network models, and inserting a bedding structure model at a layering position to obtain a three-dimensional joint-containing coal rock large-size model; slicing and cutting the three-dimensional joint-containing coal rock large-size model to obtain small slices; and carrying out image binarization processing on the plurality of small slices, and sequentially combining the small slices to reconstruct three-dimensional diversified coal rock numerical models with different sizes, different joint angles and different joint densities. According to the method, the accuracy of numerical simulation of the coal rock by the coal rock numerical model is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of rock mass engineering, and particularly relates to a method for reconstructing a numerical model of coal and rock considering the distribution of primary joint structures. Background Art

[0002] Under the influence of geological factors, coal and rock contain a large number of primary joints, which are distributed in a weak layer-like manner. The penetration of joint surfaces in coal and rock causes the cracking of coal seams and the formation of faults, making the coal body lose integrity and continuity, resulting in problems such as coal seam penetration and water inrush.

[0003] It is difficult to accurately visualize the internal primary joint structure of coal and rock and characterize its fracture process in indoor tests, and it is difficult to clearly obtain the specific process of the damage of complex joints in coal and rock to coal and rock. Therefore, numerical simulation is used to simulate indoor test specimens, avoiding problems such as high test costs, difficult operations, and inconvenience for extensive implementation. The numerical simulation method has been gradually carried out in the field of geological engineering. Its basic principle is to discretize the rock model into a network structure composed of multiple small units. However, in the traditional numerical simulation method, the boundaries of various media in each rock are often unclear when dividing the grid, resulting in low accuracy of numerical simulation of rocks. Summary of the Invention

[0004] Based on this, it is necessary to provide a method for reconstructing a numerical model of coal and rock considering the distribution of primary joint structures to solve the above technical problems. This method can improve the accuracy of numerical simulation of coal and rock by the numerical model of coal and rock.

[0005] The present invention adopts the following technical solutions:

[0006] The present invention provides a method for reconstructing a numerical model of coal and rock considering the distribution of primary joint structures, including:

[0007] Collecting joint coal and rock images;

[0008] According to the joint coal and rock images, statistically analyzing the joint distribution law, and respectively determining the frequency distribution histograms of bedding, face cleats, and end cleats according to the joint distribution law, and respectively fitting the probability distribution functions of bedding, face cleats, and end cleats; the joint distribution law includes the number of bedding, the number of face cleats, the number of end cleats, the bedding interval distance, the face cleat interval distance, and the end cleat interval distance; the abscissa of the frequency distribution histogram is the interval distance, and the ordinate is the frequency;

[0009] According to the number of face cleats, the number of end cleats, the probability distribution function of face cleats, and the probability distribution function of end cleats, constructing a network model of the single-layer cleat structure of coal and rock through modeling software, and using the method of constructing the network model of the single-layer cleat structure of coal and rock to construct multiple two-dimensional random cleat structure network models;

[0010] Stack multiple two-dimensional random fracture structure network models to obtain a stacked model, and insert a bedding structure model at the layered position of the stacked model to obtain a three-dimensional jointed coal and rock large-size model; the bedding structure model is a fracture network distribution structure perpendicular to each other in coal and rock.

[0011] Perform slicing processing on the three-dimensional jointed coal and rock large-size model to obtain large slices, and crop the large slices according to the pixel coordinate position and size to obtain small slices.

[0012] Perform image binarization processing on multiple small slices to distinguish various different joints to obtain sorted small slices.

[0013] Combine the sorted small slices in sequence to reconstruct three-dimensional diversified coal and rock numerical models with different sizes, different joint angles, and different joint densities.

[0014] Preferably, according to the number of face fractures, the number of end fractures, the probability distribution function of face fractures, and the probability distribution function of end fractures, construct a single-layer fracture structure network model of coal and rock through modeling software, specifically including:

[0015] Define the canvas size, the number of face fractures, and the number of end fractures in the modeling software.

[0016] Generate face fracture lines through a random number generation algorithm according to the number of face fractures and the parameters in the probability distribution function of face fractures.

[0017] Based on the position and coordinates of the generated face fracture lines, generate end fracture lines between adjacent face fracture lines through a random number generation algorithm according to the number of end fractures and the parameters in the probability distribution function of end fractures, and calculate the starting and ending point coordinates of the generated end fracture lines.

[0018] Export the coordinate points of the generated face fracture lines and end fracture lines, and construct a single-layer fracture structure network model according to the coordinate points.

[0019] Preferably, the thickness of the single-layer fracture structure network model of coal and rock is the interval distance between any two bedding layers.

[0020] Preferably, perform slicing processing on the three-dimensional jointed coal and rock large-size model to obtain large slices, specifically including:

[0021] Set the size of the three-dimensional jointed coal and rock large-size model according to the joint distribution law, and select the final model superposition surface.

[0022] Perform slicing processing on the final model superposition surface to obtain large slices.

[0023] Change the red, green, and blue values of the joints in the large slices from the original gray value to the red, green, and blue thresholds to obtain the modified large slices.

[0024] Export the modified large slices in sequence.

[0025] Preferably, perform image binarization on multiple small slices to distinguish multiple different joints, and obtain sorted small slices, specifically including:

[0026] Re-color multiple small slices presenting red, green, and blue respectively according to the binarization process to obtain multiple re-colored small slices;

[0027] For each re-colored small slice, set different gray values for the small slice according to the color of the re-colored small slice;

[0028] Perform complete threshold segmentation on bedding planes, face cleats, and end cleats in the coal and rock according to the gray values of the small slices to obtain sorted small slices.

[0029] Preferably, the coal and rock images are multiple images continuously taken from different directions and angles, covering joint areas of different sizes.

[0030] Preferably, the method further includes:

[0031] After reconstructing a three-dimensional diversified coal and rock numerical model with different sizes, different joint angles, and different joint densities, import the small slices and determine the content of each medium; the medium includes bedding planes, end cleats, face cleats, and matrix;

[0032] If the content of each medium is accurate, it is determined that the reconstruction of the three-dimensional diversified coal and rock numerical model is completed. If the content of each medium is incorrect, reconstruct the large-size model of three-dimensional jointed coal and rock.

[0033] The present invention provides a device for reconstructing a coal and rock numerical model considering the distribution of primary joint structures, including:

[0034] An acquisition module for acquiring jointed coal and rock images;

[0035] A first determination module for, according to the jointed coal and rock images, statistically analyzing the joint distribution law, respectively determining the frequency distribution histograms of bedding planes, face cleats, and end cleats according to the joint distribution law, and respectively fitting the probability distribution functions of bedding planes, face cleats, and end cleats; the joint distribution law includes the number of bedding planes, the number of face cleats, the number of end cleats, the bedding plane interval distance, the face cleat interval distance, and the end cleat interval distance; the abscissa of the frequency distribution histogram is the interval distance, and the ordinate is the frequency;

[0036] A construction module for, according to the number of face cleats, the number of end cleats, the probability distribution function of face cleats, and the probability distribution function of end cleats, constructing a coal and rock single-layer cleat structure network model through modeling software, and using the method of constructing the coal and rock single-layer cleat structure network model to construct multiple two-dimensional random cleat structure network models;

[0037] A second determination module, configured to stack a plurality of two-dimensional random fracture structure network models to obtain a stacked model, and insert a bedding structure model at the layering position of the stacked model to obtain a three-dimensional jointed coal and rock large-size model; the bedding structure model is a fracture network distribution structure perpendicular to each other in coal and rock.

[0038] A first generation module slices the three-dimensional jointed coal and rock large-size model to obtain large slices, and crops the large slices according to the pixel coordinate positions and sizes to obtain small slices.

[0039] A second generation module is configured to perform image binarization processing on a plurality of small slices to distinguish multiple different joints, and obtain sorted small slices.

[0040] A reconstruction module is configured to sequentially combine the sorted small slices to reconstruct three-dimensional diversified coal and rock numerical models with different sizes, different joint angles, and different joint densities.

[0041] The present invention provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the above-mentioned method for reconstructing a coal and rock numerical model considering the distribution of primary joint structures is implemented.

[0042] The present invention provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the above-mentioned method for reconstructing a coal and rock numerical model considering the distribution of primary joint structures is implemented.

[0043] The above at least one technical solution adopted by the present invention can achieve the following beneficial effects:

[0044] Collect joint coal-rock images; respectively count the interval distances and quantities of bedding, face cleats, and end cleats based on the coal-rock images, respectively determine the frequency distribution histograms of bedding, face cleats, and end cleats, respectively fit the probability distribution functions of bedding, face cleats, and end cleats, and generate the spatial distributions of each joint according to the actual statistical laws, so that the generated coal-rock model is more in line with the structural characteristics of natural coal-rock; according to the interval distances and quantities of face cleats and end cleats and the probability distribution functions of face cleats and end cleats, construct a single-layer coal-rock cleat structure network model through modeling software, and import the coordinates of multiple groups of face cleats and end cleats in the single-layer coal-rock cleat structure network model into the modeling software to construct multiple two-dimensional random cleat structure network models; stack multiple two-dimensional random cleat structure network models to obtain a stacked model, and randomly insert bedding structure models at the stratification of the stacked model to obtain a three-dimensional large-scale jointed coal-rock model. Randomly inserting bedding to construct a three-dimensional large-scale jointed coal-rock model has a wider simulation range, and the relative positions, scales, and morphologies of joints and matrix are reasonably restored, making the simulation results more representative and meeting the requirements in actual engineering applications; perform slicing processing on the three-dimensional large-scale jointed coal-rock model to obtain large slices, and crop the large slices according to the pixel coordinate positions and sizes to obtain small slices; perform image binaryzation processing on multiple small slices to distinguish various different joints to obtain sorted small slices; combine the sorted small slices in sequence to reconstruct three-dimensional diversified coal-rock numerical models with different sizes, different joint angles, and different joint densities. The slice binaryzation and cropping processing clearly distinguish the relationship between joints and matrix in the coal-rock model, effectively avoiding the problem of blurred boundaries between joints and matrix in traditional methods. This zoning processing can accurately define different structural units of the coal-rock model and improve the accuracy of numerical simulation of coal-rock by the three-dimensional diversified coal-rock numerical model. Brief Description of the Drawings

[0045] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0046] Figure 1 It is a schematic flow chart of a method for reconstructing a coal-rock numerical model considering the distribution of primary joint structures provided by the present invention;

[0047] Figure 2 It is a frequency histogram of the distribution intervals of each joint provided by the present invention;

[0048] Figure 3 It is a schematic diagram of a two-dimensional random cleat structure network model provided by the present invention;

[0049] Figure 4 It is a schematic diagram of inserting a bedding structure plane at the stratification of the cleat network provided by the present invention;

[0050] Figure 5 Schematic diagram of the large-scale three-dimensional jointed coal-rock model provided by the present invention;

[0051] Figure 6 Schematic diagram of the large slice of the large-scale three-dimensional jointed coal-rock model provided by the present invention;

[0052] Figure 7 Schematic diagram of the slice of the coal-rock model reconstructed in different distribution forms after binarization provided by the present invention;

[0053] Figure 8 Schematic diagram of the specimen of the large-scale three-dimensional jointed coal-rock model provided by the present invention;

[0054] Figure 9 Schematic diagram of the flow of the method for reconstructing and simulating the coal-rock numerical model considering the joint distribution provided by the present invention;

[0055] Figure 10 Schematic diagram of the device for reconstructing the coal-rock numerical model considering the distribution of primary joint structures provided by the present invention;

[0056] Figure 11 Schematic diagram of the computer device for implementing the method for reconstructing the coal-rock numerical model considering the distribution of primary joint structures provided by the present invention. Detailed implementation manners

[0057] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0058] Devices such as desktop computers, servers, laptop computers, etc. that can execute the solutions of the present invention. For the convenience of description, only the server is used as the execution entity for description below.

[0059] Considering the influence of coal rock joint planes is an important basis for studying the mechanical characteristics and stability of coal rock. In addition, the distribution of joints in coal rock is affected by many factors such as sedimentary environment, tectonic stress, and rock formation properties, and the distribution angle of coal rock joints has great spatial variability. Therefore, considering the influence of the structural distribution of joint planes in coal rock has important theoretical and practical significance for further research on coal rock. Since it is difficult to accurately visualize the original joint structure inside coal rock and characterize its fracture process in indoor experiments, it is difficult to clearly obtain the specific process of complex joints in coal rock destroying coal rock. Therefore, numerical simulation is used to simulate indoor test specimens to avoid problems such as high test cost, difficult operation, and inconvenience in widespread development. Numerical simulation methods are widely used in the field of geological engineering. The basic principle is to discretize the rock model into a network structure composed of multiple small units, but when dividing the grid, the boundaries of each medium are often unclear, resulting in calculation distortion.

[0060] Therefore, the present invention proposes a method for reconstructing a coal rock numerical model taking into account the distribution of primary joint structures.

[0061] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0062] Figure 1 The figure is a flow chart of a method for reconstructing a coal rock numerical model taking into account the distribution of primary joint structures in the present invention, which specifically includes the following steps:

[0063] S101: Collect jointed coal rock images.

[0064] In an exemplary embodiment, the coal rock image is a plurality of images taken continuously from different directions and angles, covering joint areas of different sizes.

[0065] Specifically, according to the morphological characteristics of coal rock joints, joints are divided into bedding and cleats, and cleats are divided into face cleats and end cleats. Generally speaking, bedding is relatively continuous and parallel, while cleats are discontinuous and staggered. Bedding, face cleats and end cleats are structural planes in three directions that are perpendicular to each other. The bedding plane has the largest range and the longest extension, followed by face cleats. The extension range of face cleats is between adjacent bedding planes, and the extension range of end cleats is between adjacent face cleats. When measuring the occurrence of coal rock joints on site, the camera used for shooting must be arranged in a section where the occurrence of joints can be easily measured and relevant geological data can be collected. Therefore, the uniform distribution method is generally not used mechanically to observe joints. Taking into account the joints developed in different directions and avoiding statistical deviations, it is generally required to have at least two survey lines for observation, and the survey lines on outcrops with both planes and sections are selected to facilitate comprehensive observation of joints. Record the specific position, direction and other relevant information of each image.

[0066] S102: According to the jointed coal rock image, the joint distribution law is statistically analyzed, and the frequency distribution histograms of bedding, face cleats and end cleats are determined according to the joint distribution law, and the probability distribution functions of bedding, face cleats and end cleats are fitted respectively; the joint distribution law includes the number of beddings, the number of face cleats, the number of end cleats, the bedding interval distance, the face cleat interval distance and the end cleat interval distance; the horizontal axis of the frequency distribution histogram is the interval distance, and the vertical axis is the frequency.

[0067] Specifically, the bedding, face cleat and end cleat are distinguished according to the arrangement orientation of field measurements. The joint planes are perpendicular to each other, and the horizontal area of ​​the bedding plane accounts for the largest proportion, followed by the face cleat. The face cleat is vertically distributed between adjacent bedding planes, and the end cleat is vertically distributed between adjacent face cleats. According to the distance, the specific area is demarcated, and the distribution range of joint length and interval distance is observed at different viewing angles and different magnifications. The frequency distribution diagrams of their number and interval distance are counted respectively, and the probability distribution function of each joint spacing is obtained by fitting calculation. Figure 2 Figure (a) is the frequency distribution histogram of the face cleat spacing distance. Figure 2 Figure (b) is the frequency distribution histogram of the end cleat spacing distance. Figure 2 Figure (c) is the frequency distribution histogram of the bedding interval distance, which is given by Figure 2 It is found that the spacing and frequency distribution of face cleats, end cleats and bedding conform to the exponential distribution. The number of joints measured within the range of 1m, 2m, 4m and 10m is basically Poisson distribution. Table 1 shows the mean value of the number and spacing of each joint within the range of 4m.

[0068] Table 1

[0069] Mean value Bedding Face cleat End cleat Quantity / each 375 150 60 Adjacent spacing / mm 10 25 60

[0070] S103: According to the number of face cleats, the number of end cleats, the probability distribution function of face cleats and the probability distribution function of end cleats, a single-layer cleat structure network model of coal rock is constructed through modeling software, and multiple sets of coordinates of face cleats and end cleats in the single-layer cleat structure network model of coal rock are imported into the modeling software to construct multiple two-dimensional random cleat structure network models.

[0071] In an exemplary embodiment, according to the number of face cleats, the number of end cleats, the probability distribution function of face cleats, and the probability distribution function of end cleats, a single-layer coal-rock cleat structure network model is constructed through modeling software, which specifically includes: defining the canvas size, the number of face cleats, and the number of end cleats in the modeling software; generating face cleat lines according to the number of face cleats and the parameters in the probability distribution function of face cleats through a random number generation algorithm; generating end cleat lines between adjacent face cleat lines according to the number of end cleats and the parameters in the probability distribution function of end cleats based on the positions and coordinates of the generated face cleat lines, and calculating the starting and ending point coordinates of the generated end cleat lines; exporting the coordinate points of the generated face cleat lines and end cleat lines, and constructing a single-layer cleat structure network model according to the coordinate points.

[0072] Specifically, set the canvas size of 800×800mm within the actual area of 4m×4m; set the total number of face cleats and end cleats in the Matrix Laboratory (MATLAB) program according to the mean values of the distribution quantities of face cleats and end cleats, the mean distance between adjacent joint surfaces, and its corresponding exponential distribution function, and randomly generate cleat network lines according to the distribution law; calculate the starting and ending point coordinate values of face cleats and end cleats by classification; import the cleat coordinate points into AutoCAD (Automated Computer-Aided Design) to reproduce the single-layer coal-rock cleat structure network model.

[0073] Specifically, loop through the construction process of the single-layer coal-rock cleat structure network model, and use the exported coordinate points to reproduce multiple cleat grid lines in AutoCAD to implement single-layer cleat network structures with various arrangements and distributions, and obtain a two-dimensional random cleat structure network model, as Figure 3 shown in the schematic diagrams of the two-dimensional random cleat structure network model taken from different angles.

[0074] S104: Stack multiple two-dimensional random cleat structure network models to obtain a stacked model, and insert a bedding structure model at the stratification of the stacked model to obtain a three-dimensional large-scale coal-rock model with joints; the bedding structure model is a distribution structure of mutually perpendicular cleat networks in coal-rock.

[0075] In an exemplary embodiment, the thickness of the single-layer coal-rock cleat structure network model is the distance between any two bedding layers.

[0076] Specifically, convert the intervals randomly generated according to the probability distribution of the bedding structure into the thickness of each layer of the cleat network structure and insert the bedding structure into the three-dimensional cleat network. Figure 4 is a schematic diagram of inserting a bedding structure at the stratification of two layers of cleat network structures. Figure 4The two figures in it respectively show the schematic diagrams of the bedding structure inserted into the two-layer fracture network structure from different angles, and continuously superimposed to obtain a large-scale three-dimensional jointed coal-rock model. Figure 5 It is a schematic diagram of a large-scale three-dimensional jointed coal-rock model. Figure 5 The two figures in it respectively show the schematic diagrams of a large-scale three-dimensional jointed coal-rock model from different angles.

[0077] S105: Perform slicing processing on the large-scale three-dimensional jointed coal-rock model to obtain large slices, and crop the large slices according to the pixel coordinate positions and sizes to obtain small slices.

[0078] In an exemplary embodiment, perform slicing processing on the large-scale three-dimensional jointed coal-rock model to obtain large slices, specifically including: setting the size of the large-scale three-dimensional jointed coal-rock model according to the joint distribution law, and selecting the final model superposition surface; performing slicing processing on the final model superposition surface to obtain large slices; changing the red, green, and blue values of the joints in the large slices from the original gray values to the red, green, and blue thresholds to obtain the modified large slices; sequentially exporting the modified large slices.

[0079] Specifically, set the overall size of the model according to the simulation calculation requirements, and select the final model superposition surface; perform slicing processing on the final superposition surface in MATLAB; change the pixel regions with different gray values in the large slices to the setting methods of the three primary colors RGB of red, green, and blue, namely (x, 0, 0), (0, y, 0), (0, 0, z); sequentially export the sliced large model with modified RGB values. Figure 6 Figure (a) in it is a schematic diagram of a large slice of a large-scale three-dimensional jointed coal-rock model, which is a grayscale image. Figure 6 Figure (b) in it is a schematic diagram of a large slice of the three primary colors of a large-scale three-dimensional jointed coal-rock model, which is a red, green, and blue image.

[0080] According to different stress states and different geological structure characteristics, in order to reconstruct diversified coal-rock models with different sizes, angles, and densities, further crop the large slices of the three primary colors sequentially according to the required pixel size and angle settings to obtain the small slices of the required models. At the same time, perform image binarization processing on the small slices to distinguish various joints and make their edges with the matrix clear. According to the final calculation requirements, set the slice size to be 150×300 pixels, and the joint plane dip angle to be 15°; rotate the large slices of the three primary colors sequentially according to the set angle, and intercept small slices with a required pixel size of 150×300 at the coordinate (440, 350) of the large slices of the three primary colors.

[0081] S106: Perform image binarization processing on multiple small slices to distinguish various different joints to obtain sorted small slices.

[0082] In an exemplary embodiment, image binarization is performed on multiple small slices to distinguish various different joints, and sorted small slices are obtained. Specifically, it includes: recoloring multiple small slices presenting red, green, and blue respectively according to binarization processing to obtain multiple recolored small slices; for each recolored small slice, setting different gray values for the small slice according to the color of the recolored small slice; performing complete threshold segmentation on bedding planes, plane cleats, and end cleats in the coal and rock according to the gray values of the small slices to obtain sorted small slices.

[0083] Specifically, the principle of the binarization processing process is to use a MATLAB program to recolor the small slice images intercepted presenting the three primary colors, and respectively set different gray values for the cases where the R value > G, B value, G value > R, B value, B value > R, G value. According to the gray values of the small slices, complete threshold segmentation is performed on bedding planes, plane cleats, and end cleats in the coal and rock to obtain sorted small slices for the model to further distinguish media.

[0084] Specifically, use a MATLAB program to perform threshold recognition and change processing on the small slices, change the threshold at the position where R > G, B value to (200, 200, 200), change the threshold at the position where G > R, B value to (125, 125, 125), change the threshold at the position where B > R, G value to (230, 230, 230), and fill the threshold of the matrix part except at the joint position with (50, 50, 50) to achieve binarization processing of each part of the medium. Figure 7 Figure (a) in it is a schematic diagram of a slice of a coal and rock model with a relatively dense joint content. Figure 7 Figure (b) in it is a schematic diagram of a slice of a coal and rock model with a relatively sparse joint content. Figure 7 Figure (c) in it is for 45 ° a schematic diagram of a slice of a coal and rock model with a

[0085] S107: Combine the sorted small slices in sequence to reconstruct three-dimensional diversified coal and rock numerical models with different sizes, different joint angles, and different joint densities.

[0086] Specifically, according to the requirements of coal and rock experiments, in the software AVIZO for three-dimensional image processing and visualization analysis, combine the required small slices in sequence to reconstruct three-dimensional diversified coal and rock numerical models with different sizes, different joint angles, and different joint densities. Figure 8 It is a schematic diagram of a three-dimensional coal and rock model specimen, with the average proportion of bedding planes being 10%, the average proportion of plane cleats being 3.7%, and the average proportion of end cleats being 2.65%.

[0087] In an exemplary embodiment, the method further includes: after reconstructing a three-dimensional diversified coal-rock numerical model with different sizes, different joint angles, and different joint densities, importing small slices and determining the content of each medium; the medium includes bedding, end cleats, face cleats, and matrix; if the content of each medium is accurate, it is determined that the reconstruction of the three-dimensional diversified coal-rock numerical model is completed, and if the content of each medium is incorrect, the construction of the three-dimensional large-size jointed coal-rock model is restarted.

[0088] Specifically, import the small slices into AVIZO, and determine whether the three-dimensional diversified coal-rock numerical model is accurate by identifying each medium and counting the medium content. Divide and identify each medium (matrix, face cleat, end cleat, and bedding) in the coal-rock according to the pixel threshold, observe whether the boundary is clear, and count the content respectively to measure whether the model meets the expected requirements. Or when setting the joint dip angle, judge whether the angle is accurate according to the final model. Then the reconstruction of the three-dimensional large-size jointed coal-rock model is completed. If the identified content is incorrect, check the reasons and optimize and adjust the reconstructed coal-rock slice image. For each step in S101 - S107, if there is a problem, return to the previous step to check where the problem is, and repeatedly call the instructions of each step to execute a coal-rock numerical model reconstruction method considering the distribution of primary joints in S101 - S107. Compare the effect of the three-dimensional large-size jointed coal-rock model with the actual geological observation data, and optimize the model according to the AVIZO verification results, continuously adjusting the parameters to improve the accuracy of the model.

[0089] When applying the coal-rock numerical model reconstruction method considering the distribution of primary joint structures provided by the present invention, it is not necessary to execute according to Figure 1 the order of the steps shown. The specific execution order of each step can be determined as needed, and the present invention does not limit this.

[0090] In an exemplary embodiment, as Figure 9 shown, the present invention provides a flowchart of a coal-rock numerical model reconstruction and simulation method considering joint distribution, and the specific steps are as follows:

[0091] Step 1: Collect jointed coal-rock graphics.

[0092] Step 2: Distinguish and measure the joints, count the number and spacing of each structural plane (bedding, cleats), and calculate the joint spacing frequency histogram.

[0093] Step 3: Use MATLAB to establish a two-dimensional single-layer cleat network structure model by fitting the probability distribution function and distribution characteristics.

[0094] Step 4: Use AutoCAD to reproduce multiple groups of cleat network structures.

[0095] Step 5: Randomly insert bedding structures in the three-dimensional reconstructed fracture network structure according to the probability distribution using MATLAB to construct a three-dimensional large-scale coal-rock model.

[0096] Step 6: Process the large model for the adaptation angle to obtain large slices.

[0097] Step 7: Cut and binarize according to requirements to obtain sorted small slices.

[0098] Step 8: Transfer the small slices into AVIZO to reconstruct the required numerical model.

[0099] Step 9: Optimize the model according to the recognition results of each joint.

[0100] In an exemplary embodiment, the present invention discloses a method for reconstructing a coal-rock numerical model considering the distribution of primary joint structures. First, based on the joint characteristics and distribution statistical laws of coal-rock, use the MATLAB program to generate a primary fracture network structure in a specified range according to the statistical laws, randomly insert bedding structures according to the bedding distribution law to reconstruct and build a large-scale coal-rock model, and finally combine slice binarization and interception processing to obtain a three-dimensional coal-rock numerical model that meets the demand settings under multiple factors, effectively solving the problem that the joints and matrix of the coal-rock numerical model are not clearly distinguished under various factors for further research and analysis. The coal-rock numerical model of the present invention considering joint distribution has higher efficiency and economy compared with traditional sampling, and at the same time reflects the size effect of coal-rock and the influence of joint distribution positions. During the model establishment process, various influencing factors (such as environmental variables such as stress, temperature, and humidity) are combined for adjustment and optimization to generate a coal-rock numerical model that meets actual conditions. This provides accurate input data for further simulation analysis and can deeply analyze the behavioral characteristics of coal-rock under different working conditions. For fields such as coal mining and underground engineering, especially in the case where the coal-rock joint structure is rich and the complex properties have a greater impact, the method for establishing a coal-rock numerical model considering the distribution of primary joints provided by the present invention plays a guiding role.

[0101] The above is a method for reconstructing a coal-rock numerical model considering the distribution of primary joint structures provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding device for reconstructing a coal-rock numerical model considering the distribution of primary joint structures, as Figure 10 shown.

[0102] Figure 10 The following is a schematic diagram of a device for reconstructing a coal-rock numerical model considering the distribution of primary joint structures provided by the present invention, including:

[0103] A collection module 1001, configured to collect joint coal-rock images.

[0104] The first determination module 1002 is configured to count the joint distribution law according to the joint coal-rock image, and respectively determine the frequency distribution histograms of bedding, face cleats, and end cleats according to the joint distribution law, and respectively fit the probability distribution functions of bedding, face cleats, and end cleats; the joint distribution law includes the number of bedding, the number of face cleats, the number of end cleats, the bedding interval distance, the face cleat interval distance, and the end cleat interval distance; the abscissa of the frequency distribution histogram is the interval distance, and the ordinate is the frequency.

[0105] The construction module 1003 is configured to construct a single-layer coal-rock cleat structure network model through modeling software according to the number of face cleats, the number of end cleats, the probability distribution function of face cleats, and the probability distribution function of end cleats, and construct multiple two-dimensional random cleat structure network models by using the method of constructing the single-layer coal-rock cleat structure network model.

[0106] The second determination module 1004 is configured to stack multiple two-dimensional random cleat structure network models to obtain a stacked model, and insert a bedding structure model at the stratification of the stacked model to obtain a three-dimensional large-size joint coal-rock model; the bedding structure model is a mutually perpendicular cleat network distribution structure in coal-rock.

[0107] The first generation module 1005 is configured to perform slicing processing on the three-dimensional large-size joint coal-rock model to obtain large slices, and crop the large slices according to the pixel coordinate positions and sizes to obtain small slices.

[0108] The second generation module 1006 is configured to perform image binarization processing on multiple small slices to distinguish various different joints to obtain sorted small slices.

[0109] The reconstruction module 1007 is configured to sequentially combine the sorted small slices to reconstruct three-dimensional diversified coal-rock numerical models with different sizes, different joint angles, and different joint densities.

[0110] For the specific limitations of a device for reconstructing a coal-rock numerical model considering the distribution of primary joint structures, reference may be made to the limitations of a method for reconstructing a coal-rock numerical model considering the distribution of primary joint structures in the above text, which will not be elaborated here. Each module in the above device for reconstructing a coal-rock numerical model considering the distribution of primary joint structures can be implemented in whole or in part by software, hardware, and their combinations. The above modules can be embedded in or independent of the processor in a computer device in the form of hardware, or stored in the memory of the computer device in the form of software, so as to facilitate the processor to call and execute the operations corresponding to the above modules.

[0111] The present invention also provides a computer-readable storage medium, which stores a computer program, and the computer program can be used to execute the above Figure 1 Provided is a method for reconstructing a coal-rock numerical model considering the distribution of primary joint structures.

[0112] The present invention also provides Figure 11 a schematic structural diagram of the computer device shown in the figure, such as Figure 11 shown, at the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include other hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to implement the above Figure 1 a method for reconstructing a coal-rock numerical model considering the distribution of native joint structures provided

[0113] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided by the present invention can include at least one of non-volatile and volatile memories. The non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical memory, etc. The volatile memory can include random access memory (RAM) or an external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0114] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded by the present invention.

Claims

1. A method for reconstructing a numerical model of coal and rock considering the distribution of primary joint structures, characterized in that Including: Collecting joint coal-rock images; According to the joint coal-rock images, statistically analyzing the joint distribution law, and respectively determining the frequency distribution histograms of bedding, plane cleats, and end cleats according to the joint distribution law, and respectively fitting the probability distribution functions of bedding, plane cleats, and end cleats; the joint distribution law includes the number of bedding, the number of plane cleats, the number of end cleats, the bedding interval distance, the plane cleat interval distance, and the end cleat interval distance; the abscissa of the frequency distribution histogram is the interval distance, and the ordinate is the frequency; According to the number of plane cleats, the number of end cleats, the probability distribution function of plane cleats, and the probability distribution function of end cleats, constructing a single-layer coal-rock cleat structure network model through modeling software, and importing the coordinates of multiple groups of plane cleats and end cleats in the single-layer coal-rock cleat structure network model into the modeling software to construct multiple two-dimensional random cleat structure network models; Stacking multiple two-dimensional random cleat structure network models to obtain a stacked model, and inserting a bedding structure model at the layering position of the stacked model to obtain a three-dimensional large-scale joint coal-rock model; the bedding structure model is a mutually perpendicular cleat network distribution structure in coal-rock; Performing slicing processing on the three-dimensional large-scale joint coal-rock model to obtain large slices, and cropping the large slices according to the pixel coordinate positions and sizes to obtain small slices; Performing image binaryzation processing on multiple small slices to distinguish various different joints to obtain sorted small slices; Sequentially combining the sorted small slices to reconstruct three-dimensional diversified coal-rock numerical models with different sizes, different joint angles, and different joint densities.

2. The method according to claim 1, characterized in that, The constructing a single-layer coal-rock cleat structure network model through modeling software according to the number of plane cleats, the number of end cleats, the probability distribution function of plane cleats, and the probability distribution function of end cleats specifically includes: Defining the canvas size, the number of plane cleats, and the number of end cleats in the modeling software; Generating plane cleat lines through a random number generation algorithm according to the number of plane cleats and the parameters in the probability distribution function of plane cleats; Based on the position and coordinates of the generated plane cleat lines, using a random number generation algorithm to generate end cleat lines between adjacent plane cleat lines according to the number of end cleats and the parameters in the probability distribution function of end cleats, and calculating the starting and ending point coordinates of the generated end cleat lines; Exporting the coordinate points of the generated plane cleat lines and end cleat lines, and constructing the single-layer cleat structure network model according to the coordinate points.

3. The method according to claim 1, characterized in that, The thickness of the single-layer coal-rock cleat structure network model is the interval distance between any two layers of bedding.

4. The method according to claim 1, characterized in that The performing slicing processing on the three-dimensional large-scale joint coal-rock model to obtain large slices specifically includes: Setting the size of the three-dimensional large-scale joint coal-rock model according to the joint distribution law, and selecting the final model superposition surface; Performing slicing processing on the final model superposition surface to obtain large slices; Changing the red, green, and blue values of the joints in the large slices from the original gray values to the red, green, and blue thresholds to obtain the modified large slices; Sequentially exporting the modified large slices.

5. The method according to claim 1, characterized in that, The performing image binaryzation processing on multiple small slices to distinguish various different joints to obtain sorted small slices specifically includes: Repaint multiple small slices presenting red, green, and blue respectively through binarization processing to obtain multiple repainted small slices; For each repainted small slice, set different grayscale values for the small slice according to the color of the repainted small slice; Completely threshold segment bedding, plane cleats, and end cleats in the coal rock according to the grayscale values of the small slices to obtain the sorted small slices.

6. The method according to claim 1, wherein The coal rock image is multiple images continuously taken from different directions and angles, covering joint areas of different sizes.

7. The method according to claim 1, characterized in that, The method further includes: After reconstructing a three-dimensional diversified coal rock numerical model with different sizes, joint angles, and joint densities, import the small slices and determine the content of each medium; the medium includes bedding, end cleats, plane cleats, and matrix; If the content of each medium is accurate, determine that the reconstruction of the three-dimensional diversified coal rock numerical model is completed; if the content of each medium is incorrect, reconstruct the large-size model of the three-dimensional jointed coal rock again.

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