Method, electronic device and storage medium for reconstructing surrounding rock fractures in three-dimensional simulation test

Abstract

The present invention discloses a method for reconstructing surrounding rock fractures in a three-dimensional simulation test, an electronic device and a storage medium. The method comprises: obtaining the porosity of a coal mining model after simulating coal mining in a three-dimensional simulation experiment as the porosity after coal mining; obtaining the distribution probability of solid phase growth nuclei obtained by statistics of each grid on the coal mining model, and the growth probability of solid phase growth nuclei in multiple directions of each grid; generating a digital model of fractures after coal mining according to the porosity after coal mining, the distribution probability of solid phase growth nuclei of each grid, and the growth probability of solid phase growth nuclei in multiple directions of each grid; outputting the digital model of fractures after coal mining to a three-dimensional printing device, and the three-dimensional printing device reconstructing the digital model of fractures after coal mining into a three-dimensional model of fractures. The present invention combines the model parameters of the three-dimensional simulation model to establish a three-dimensional model of fractures, realizes the reconstruction of the model, and solves the problems of low monitoring accuracy of surrounding rock fracture fields and inaccurate three-dimensional reconstruction models in three-dimensional simulation experiments.

Description

Technical Field

[0001] The present invention relates to the technical field related to coal mines, and in particular to a method for reconstructing surrounding rock fissures, an electronic device and a storage medium in three-dimensional simulation tests. Background Technique

[0002] Currently, there are two types of equipment for monitoring the surrounding rock fissure field, borehole television and CT imaging.

[0003] The borehole television imager, such as KDVJ–400, uses a high-resolution color television camera for monitoring, displays the structure of the borehole inner wall on a liquid crystal display screen, can monitor the overall situation inside the hole, and can record videos. The digital panoramic borehole camera system adopts the new concept of panoramic images, is processed by digital technology, has good real-time performance, a large observation range, high measurement accuracy, automated detection process and powerful digital processing capabilities, can accurately obtain parameters such as the attitude of structural planes and fissure widths inside the borehole, and can form a planar unfolded diagram and a three-dimensional borehole core diagram after seamless splicing processing.

[0004] As a non-destructive testing method, the CT scanning imaging system can quickly and non-destructively obtain the internal structure distribution characteristics of rocks by using its scanning imaging principle and the visualization function of three-dimensional reconstruction. In the industrial CT scanning imaging experiment, when the X-ray penetrates the rock specimen, since the internal structure of the rock specimen is composed of mineral components with different densities, the absorption coefficients of each point for the X-ray are also different. The intensity of the X-ray attenuates during the scanning process, and the ray contains the internal structure density information of the scanned rock specimen. The imaging system receives it and converts it into the form of a digital image for convenient observation of the internal structure distribution of the rock specimen. By docking the VG Studio max software with the industrial CT scanning equipment, the original data is processed and the CT scanning slice images are exported. The CT slice image stack is vectorized by the three-dimensional visualization image processing software Avizo, and the "Interactive Thresholding" module is used for image threshold segmentation to extract the fissure part in the image, and the "Volume Rendering" module is used to display the morphology and distribution characteristics of the fissures.

[0005] However, although the existing monitoring equipment can monitor the internal fissure field of the model, due to the lack of consideration of the interference of contact monitoring, the accuracy is low, resulting in a large deviation in the results. The existing reconstruction model methods can complete the reconstruction work, but the algorithms are cumbersome, and they are not perfect enough in connecting contact points when encountering multi-phase problems, resulting in errors in the model results. Summary of the Invention

[0006] Based on this, it is necessary to provide a surrounding rock fracture reconstruction method, an electronic device, and a storage medium for three-dimensional simulation experiments to address the technical problems of low monitoring accuracy of the surrounding rock fracture field and inaccurate three-dimensional reconstruction models in the existing technology.

[0007] The present invention provides a surrounding rock fracture reconstruction method for three-dimensional simulation experiments, including:

[0008] Obtain the porosity of the coal mining model after simulated coal mining in the three-dimensional simulation experiment as the porosity after coal mining;

[0009] Obtain the distribution probability of solid-phase growth nuclei statistically obtained for each grid on the coal mining model, and the growth probability of solid-phase growth nuclei in multiple directions for each grid;

[0010] Generate a post-coal-mining fracture digital model based on the porosity after coal mining, the distribution probability of solid-phase growth nuclei for each grid, and the growth probability of solid-phase growth nuclei in multiple directions for each grid;

[0011] Output the post-coal-mining fracture digital model to a three-dimensional printing device, and the three-dimensional printing device reconstructs it into a fracture three-dimensional model according to the post-coal-mining fracture digital model.

[0012] Further:

[0013] The step of obtaining the porosity of the coal mining model after simulated coal mining in the three-dimensional simulation experiment as the porosity after coal mining specifically includes: obtaining the post-coal-mining model image of the coal mining model after simulated coal mining in the three-dimensional simulation experiment, and calculating the porosity of the coal mining model after simulated coal mining as the porosity after coal mining according to the post-coal-mining model image;

[0014] The step of obtaining the distribution probability of solid-phase growth nuclei statistically obtained for each grid on the coal mining model, and the growth probability of solid-phase growth nuclei in multiple directions for each grid specifically includes: dividing the post-coal-mining model image into multiple grids, and statistically obtaining the distribution probability of solid-phase growth nuclei for each grid and the growth probability of solid-phase growth nuclei in multiple directions for each grid according to the image information of the post-coal-mining model image.

[0015] Furthermore, the step of obtaining the post-coal-mining model image of the coal mining model after simulated coal mining in the three-dimensional simulation experiment specifically includes:

[0016] Obtain the images of the coal mining model after simulated coal mining taken by multiple camera devices located in the coal mining model in the three-dimensional simulation experiment, and fuse the images taken by the multiple camera devices to obtain the post-coal-mining model image.

[0017] Still further, it also includes:

[0018] Identify fractures from the post - coal - mining model image as the actually measured post - coal - mining fractures, and calculate the fracture change value of the actually measured post - coal - mining fractures as the actually measured post - coal - mining fracture change value;

[0019] Identify fractures from the post - coal - mining fracture digital model as the fractures to be verified, and calculate the fracture change value to be verified of the fractures to be verified;

[0020] Compare the actually measured post - coal - mining fracture change value with the fracture change value to be verified. If the difference between the actually measured post - coal - mining fracture change value and the fracture change value to be verified is less than the preset difference threshold, then determine that the post - coal - mining fracture digital model is valid; otherwise, determine that the post - coal - mining fracture digital model is invalid, and regenerate a new post - coal - mining fracture digital model according to the post - coal - mining porosity, the distribution probability of solid - phase growth nuclei in each grid, and the growth probability of solid - phase growth nuclei in each grid in multiple directions.

[0021] Furthermore, it also includes:

[0022] Obtain the porosity of the coal - mining model before coal - mining as the pre - coal - mining porosity;

[0023] Divide the coal - mining model into multiple grids, and obtain the initial distribution probability of solid - phase growth nuclei in each grid and the initial growth probability of solid - phase growth nuclei in each grid in multiple directions;

[0024] Generate an initial fracture digital model according to the pre - coal - mining porosity, the initial distribution probability of solid - phase growth nuclei in each grid, and the initial growth probability of solid - phase growth nuclei in each grid in multiple directions;

[0025] Identify fractures from the initial fracture digital model as initial fractures;

[0026] The specific method for calculating the fracture change value to be verified of the fractures to be verified includes: comparing the initial fractures with the fractures to be verified to determine the fracture change value to be verified.

[0027] Furthermore, it also includes:

[0028] Obtain the pre - coal - mining model image of the coal - mining model before simulated coal - mining in the three - dimensional simulation experiment;

[0029] Identify fractures from the pre - coal - mining model image as the actually measured pre - coal - mining fractures;

[0030] The specific method for calculating the fracture change value of the actually measured post - coal - mining fractures as the actually measured post - coal - mining fracture change value includes:

[0031] Compare the actually measured post - coal - mining fractures with the actually measured pre - coal - mining fractures, and obtain the fracture change value of the actually measured post - coal - mining fractures as the actually measured post - coal - mining fracture change value.

[0032] Further, it further includes:

[0033] Obtain the image of the coal mining process model during the simulated coal mining process in the three-dimensional simulation experiment;

[0034] Identify fissures from the image of the coal mining process model, generate the change data of the fissures with respect to the time axis and display it.

[0035] Further, the generating the digital model of the post-mining fissures according to the post-mining porosity, the distribution probability of the solid-phase growth nuclei of each grid, and the growth probability of the solid-phase growth nuclei of each grid in multiple directions specifically includes:

[0036] Construct a digital model based on the coordinates of the grid;

[0037] Traverse all the grids of the digital model. For each grid, obtain the grid node random number and the distribution probability of the solid-phase growth nuclei of the grid. If the grid node random number is less than the distribution probability of the solid-phase growth nuclei of the grid, then a solid-phase particle inner core is generated at the coordinate position corresponding to the grid in the digital model, and the grid where the solid-phase particle inner core is generated is used as an effective grid;

[0038] Perform directional growth calculation on each effective grid until the porosity of the digital model reaches the post-mining porosity;

[0039] Form contour equipotential lines based on the effective grids of the digital model, and generate a digital model of the post-mining fissures based on the contour equipotential lines;

[0040] The directional growth calculation specifically includes:

[0041] For an effective grid, obtain the surrounding node random number and the growth probability of the solid-phase growth nuclei of the effective grid in multiple directions. Take the direction in which the growth probability of the solid-phase growth nuclei of the effective grid is greater than the surrounding node random number as the growth direction, take the adjacent grid located in the growth direction of the effective grid as the growth grid, generate a solid-phase particle inner core at the coordinate position corresponding to the growth grid in the digital model, update the growth grid where the solid-phase particle inner core is generated as an effective grid, and calculate the porosity of the digital model. If the porosity of the digital model reaches the post-mining porosity, then end the directional growth calculation, otherwise select the next effective grid to perform the directional growth calculation.

[0042] The present invention provides an electronic device, including:

[0043] At least one processor; and,

[0044] A memory communicatively connected to at least one of the processors; wherein,

[0045] The memory stores instructions executable by at least one of the processors, and the instructions are executed by at least one of the processors to enable at least one of the processors to execute the method for reconstructing surrounding rock fissures in the three-dimensional simulation experiment as described above.

[0046] The present invention provides a storage medium that stores computer instructions, which are used to execute all steps of the method for reconstructing surrounding rock fissures in the three-dimensional simulation experiment as described above when the computer executes the computer instructions.

[0047] The present invention combines the model parameters of the three-dimensional simulation model, establishes a three-dimensional fissure model, realizes the reconstruction of the model, and finally uses 3D printing technology to manufacture an entity for comparison with the experimental model, solving the problems of low monitoring accuracy of the surrounding rock fissure field and inaccurate three-dimensional reconstruction model in the three-dimensional simulation experiment. At the same time, by designing a marker point camera to transmit real-time images, the development and expansion of fissures are obtained, achieving the purpose of monitoring the surrounding rock fissure field in the three-dimensional simulation experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a flowchart of a method for reconstructing surrounding rock fissures in a three-dimensional simulation experiment according to the present invention;

[0049] Figure 2 is a flowchart of a flowchart for generating a digital model of fissures after coal mining in the best embodiment of the present invention;

[0050] Figure 3 is a schematic diagram of the growth direction in the grid in the best embodiment of the present invention;

[0051] Figure 4 is a schematic diagram of the hardware structure of an electronic device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0052] The following further describes the specific embodiments of the present invention with reference to the accompanying drawings. The same components are denoted by the same reference numerals. It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the terms "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.

[0053] As Figure 1 shown is a flowchart of a method for reconstructing surrounding rock fissures in a three-dimensional simulation experiment according to the present invention, including:

[0054] Step S101, obtaining the porosity of the coal mining model after simulated coal mining in the three-dimensional simulation experiment as the porosity after coal mining;

[0055] In S102, obtain the distribution probability of solid-phase growth nuclei statistically obtained for each grid on the coal mining model, and the growth probability of solid-phase growth nuclei in multiple directions for each grid;

[0056] In step S103, generate a post-mining fracture digital model based on the post-mining porosity, the distribution probability of solid-phase growth nuclei for each grid, and the growth probability of solid-phase growth nuclei in multiple directions for each grid;

[0057] In step S104, output the post-mining fracture digital model to a 3D printing device, and the 3D printing device reconstructs it into a three-dimensional fracture model.

[0058] Specifically, simulate coal mining on the coal mining model of the three-dimensional simulation experiment. After the simulated coal mining, measure the porosity of the coal mining model. Then, take the porosity of the simulated coal mining obtained in step S101 as the post-mining porosity. Then divide the coal mining model into multiple grids. In step S102, obtain the distribution probability of solid-phase growth nuclei and the growth probability in different directions for each grid. The distribution probability and the growth probability are obtained by using existing statistical methods on the measured data of the coal mining model.

[0059] Then execute step S103 to generate a post-mining fracture digital model, that is, a three-dimensional porous medium model. And in step S104, output the generated post-mining fracture digital model to a three-dimensional (3D) printing device, and the 3D printing device manufactures an entity for comparison with the coal mining model used in the experiment.

[0060] The present invention combines the model parameters of the three-dimensional simulation model to establish a three-dimensional fracture model, realizes the reconstruction of the model, and finally uses 3D printing technology to manufacture an entity for comparison with the experimental model, solving the problems of low monitoring accuracy of the surrounding rock fracture field and inaccurate three-dimensional reconstruction model in the three-dimensional simulation experiment. At the same time, by designing a marker point camera to transmit real-time images, the development and expansion of fractures are obtained, achieving the purpose of monitoring the surrounding rock fracture field in the three-dimensional simulation experiment.

[0061] In one of the embodiments:

[0062] In the obtaining of the three-dimensional simulation experiment, taking the porosity of the coal mining model after simulated coal mining as the post-mining porosity specifically includes: obtaining the post-mining model image of the coal mining model after simulated coal mining in the three-dimensional simulation experiment, and calculating the porosity of the coal mining model after simulated coal mining based on the post-mining model image as the post-mining porosity;

[0063] The obtaining of the distribution probability of solid-phase growth nuclei statistically obtained for each grid on the coal mining model and the growth probability of solid-phase growth nuclei in multiple directions for each grid specifically includes: dividing the post-coal-mining model image into multiple grids, and according to the image information of the post-coal-mining model image, statistically obtaining the distribution probability of solid-phase growth nuclei for each grid and the growth probability of solid-phase growth nuclei in multiple directions for each grid.

[0064] Specifically, an image of the coal mining model can be taken, and based on the taken image, the porosity after coal mining, the distribution probability of solid-phase growth nuclei for each grid, and the growth probability of solid-phase growth nuclei in multiple directions for each grid can be statistically obtained.

[0065] In this embodiment, relevant parameters are determined by taking an image of the coal mining model, making the parameters more accurate.

[0066] In one of the embodiments, in the obtaining of the three-dimensional simulation experiment, the post-coal-mining model image of the coal mining model after simulated coal mining specifically includes:

[0067] Obtaining, in the three-dimensional simulation experiment, the images of the coal mining model after simulated coal mining taken by a plurality of camera devices located in the coal mining model, and fusing the images taken by the plurality of camera devices to obtain the post-coal-mining model image.

[0068] Specifically, a plurality of high-definition camera devices are placed at set points inside the model on the simulation experiment platform. After the model device is stable, simulated coal mining is carried out and images are collected. Then the collected images are uploaded to the server, and existing image processing methods are used to fuse the images collected by the plurality of camera devices to obtain the post-coal-mining model image. Specifically, binaryzation and edge detection methods can be used to obtain the contour of the feature region of the original image, and through positioning, segmentation, and decoding, the pixel coordinates of the center points of the regions are calculated. Finally, according to the scale, the difference between different pixel points is converted into the actual distance, so as to obtain the post-coal-mining model image.

[0069] In one of the embodiments, it further includes:

[0070] Identifying fissures from the post-coal-mining model image as the actually measured fissures after coal mining, and calculating the fissure change value of the actually measured fissures after coal mining as the actually measured fissure change value after coal mining;

[0071] Identifying fissures from the post-coal-mining fissure digital model as the fissures to be verified, and calculating the to-be-verified fissure change value of the to-be-verified fissures;

[0072] Compare the measured crack change value after coal mining with the crack change value to be verified. If the difference between the measured crack change value after coal mining and the crack change value to be verified is less than the preset difference threshold, it is determined that the digital crack model after coal mining is valid; otherwise, it is determined that the digital crack model after coal mining is invalid, and a new digital crack model after coal mining is generated according to the porosity after coal mining, the distribution probability of solid-phase growth nuclei in each grid, and the growth probability of solid-phase growth nuclei in each grid in multiple directions.

[0073] In this embodiment, by comparing the measured crack change value after coal mining with the crack change value to be verified, it is determined whether the digital crack model after coal mining is consistent with the actual coal mining model, thereby improving the accuracy of the digital crack model after coal mining. The method of identifying cracks from the model image can be implemented by using existing crack identification methods.

[0074] In one of the embodiments, it further includes:

[0075] Obtain the porosity of the coal mining model before coal mining as the porosity before coal mining;

[0076] Divide the coal mining model into multiple grids, and obtain the initial distribution probability of solid-phase growth nuclei in each grid and the initial growth probability of solid-phase growth nuclei in each grid in multiple directions;

[0077] Generate an initial digital crack model according to the porosity before coal mining, the initial distribution probability of solid-phase growth nuclei in each grid, and the initial growth probability of solid-phase growth nuclei in each grid in multiple directions;

[0078] Identify the cracks from the initial digital crack model as the initial cracks;

[0079] The calculation of the crack change value to be verified of the crack to be verified specifically includes: comparing the initial crack with the crack to be verified to determine the crack change value to be verified.

[0080] In this embodiment, a digital crack model is generated before coal mining, and the initial cracks are identified from the digital crack model generated before coal mining. By comparing the initial cracks with the cracks to be verified, the crack change value is obtained. The crack change value includes, but is not limited to, the crack length, width, or depth.

[0081] In one of the embodiments, it further includes:

[0082] Obtain the pre-coal-mining model image of the coal mining model before coal mining in the three-dimensional simulation experiment;

[0083] Identify the cracks from the pre-coal-mining model image as the measured cracks before coal mining;

[0084] The measured crack change value after coal mining is used as the measured crack change value after coal mining, specifically including:

[0085] Compare the measured crack after coal mining with the measured crack before coal mining, and obtain the crack change value of the measured crack after coal mining as the measured crack change value after coal mining.

[0086] Specifically, if there are no designed cracks in the coal mining model before simulated coal mining, the measured crack change value after coal mining is the relevant parameter of the measured crack after coal mining. If there are designed cracks in the coal mining model before simulated coal mining, the measured crack change value after coal mining is the comparison value between the measured crack after coal mining and the relevant parameters of the measured crack before coal mining.

[0087] In one embodiment, it further includes:

[0088] Obtain the coal mining process model image of the coal mining model during the simulated coal mining process in the three-dimensional simulation experiment;

[0089] Identify the cracks from the coal mining process model image, generate the change data of the cracks with respect to the time axis and display it.

[0090] Specifically, the crack change data is displayed in order of the time axis on the coordinate system, including the crack length change diagram and the sudden change trend diagram. The length change diagram mainly shows the process of crack change, while the sudden change trend diagram mainly presents the change amplitude during the process.

[0091] This embodiment adds the change data of the cracks with respect to the time axis, which is convenient for dynamically monitoring the surrounding rock crack field of the three-dimensional simulation test.

[0092] In one embodiment, the generation of the post-mining crack digital model according to the post-mining porosity, the distribution probability of the solid-phase growth nuclei of each grid, and the growth probability of the solid-phase growth nuclei of each grid in multiple directions specifically includes:

[0093] Construct a digital model based on the coordinates of the grid;

[0094] Traverse all the grids of the digital model. For each grid, obtain the grid node random number and the distribution probability of the solid-phase growth nuclei of the grid. If the grid node random number is less than the distribution probability of the solid-phase growth nuclei of the grid, a solid-phase particle inner core is generated at the coordinate position corresponding to the grid in the digital model, and the grid where the solid-phase particle inner core is generated is used as an effective grid;

[0095] Perform directional growth calculation on each effective grid until the porosity of the digital model reaches the post-mining porosity;

[0096] Form contour equipotential lines based on the effective grids of the digital model, and generate the post-mining crack digital model based on the contour equipotential lines;

[0097] The calculation of the growth in a specific direction specifically includes:

[0098] For a valid grid, obtain the random numbers of the surrounding nodes and the growth probabilities of the solid-phase growth nuclei of the valid grid in multiple directions. Take the direction in which the growth probability of the solid-phase growth nucleus of the valid grid is greater than the random number of the surrounding nodes as the growth direction, take the adjacent grid located in the growth direction of the valid grid as the growth grid, generate a solid-phase particle nucleus at the coordinate position corresponding to the growth grid in the digital model, update the growth grid where the solid-phase particle nucleus is generated to a valid grid, and calculate the porosity of the digital model. If the porosity of the digital model reaches the porosity after coal mining, end the calculation of the growth in the direction; otherwise, select the next valid grid and execute the calculation of the growth in the direction.

[0099] Specifically, as Figure 2 shown in the flowchart of the work for generating the digital model of fractures after coal mining, it includes:

[0100] Step S201, input parameters, including the porosity after coal mining, the distribution probability of the solid-phase growth nuclei of each grid, and the growth probabilities of the solid-phase growth nuclei of each grid in multiple directions;

[0101] Step S202, traverse all grids;

[0102] Step S203, if the random number of the grid node is less than the distribution probability of the solid-phase growth nucleus of the grid, then a solid-phase particle nucleus is generated for this grid; otherwise, execute Step S204;

[0103] For example, all grids in the digital model are initially set to zero. When a grid generates a solid-phase particle nucleus, set the corresponding position of this grid in the digital model to one;

[0104] Step S204, check if the traversal is over. If it is, execute Step S205; otherwise, execute Step S202;

[0105] Step S205, traverse all solid-phase particles and grow them towards the surroundings;

[0106] Step S206, if the random number of the surrounding node is less than the growth probability of the solid-phase growth nucleus of the grid in a certain direction, then take the direction in which the growth probability of the solid-phase growth nucleus of the grid is greater than the random number of the surrounding node as the growth direction, take the adjacent grid located in the growth direction of the valid grid as the growth grid, and generate a solid-phase particle nucleus at the coordinate position corresponding to the growth grid in the digital model; otherwise, execute Step S205;

[0107] For example, when a grid generates a solid-phase particle nucleus, set the corresponding position of this grid in the digital model to one;

[0108] Step S207, if the porosity of the digital model reaches the porosity after coal mining, execute Step S208; otherwise, execute Step S205.

[0109] Step S208, generate the equipotential lines of the particle contour according to the digital model, save the contour line data, generate the particle contour line graph, and save it as a DXF file.

[0110] Specifically, the coal mining model is divided into multiple layers, and each layer is divided into multiple grids. For example, the image of the model after coal mining is divided into multiple layers, and each layer is divided into multiple grids. The digital model also includes multiple layers, and the grids of the coal mining model correspond to the coordinate positions of the corresponding layers in the digital model. As Figure 3 shown, each grid includes growth direction 1, growth direction 2, growth direction 3, growth direction 4, growth direction 5, growth direction 6, growth direction 7, growth direction 8, where the lengths of growth directions 1 to 4 change, and the angles of growth directions 5 to 8 change. The grids in the digital model are initialized to zero. When it is determined that a solid-phase particle nucleus is generated in this grid, the corresponding position in the digital model of this grid is set to one. When the porosity of the digital model reaches the porosity after coal mining, the contour lines of the solid-phase particles are generated for each layer. For example, the contour lines are generated based on the set coordinate positions. Then, the contour line data of all layers are programmed through Auto CAD VBA, and the contour lines of all layers are stacked in sequence to form a three-dimensional image. Finally, the file type is selected as ACIS (*.dxf) for output, imported into the finite element analysis software, and the reconstruction of the crack is completed.

[0111] In addition, based on the porosity before coal mining, the initial distribution probability of the solid-phase growth nuclei of each grid, and the initial growth probability of the solid-phase growth nuclei of each grid in multiple directions, the generated initial crack digital model is consistent with the generated crack digital model after coal mining, that is:

[0112] Construct a digital model based on the coordinates of the grid;

[0113] Traverse all the grids of the digital model. For each grid, obtain the grid node random number and the distribution probability of the solid-phase growth nucleus of this grid. If the grid node random number is less than the distribution probability of the solid-phase growth nucleus of this grid, a solid-phase particle nucleus is generated at the coordinate position corresponding to this grid in the digital model, and the grid where the solid-phase particle nucleus is generated is used as an effective grid;

[0114] Perform direction growth calculation on each effective grid until the porosity of the digital model reaches the porosity before coal mining;

[0115] Form equipotential lines based on the effective grids of the digital model, and generate a crack digital model before coal mining based on the equipotential lines;

[0116] The direction growth calculation specifically includes:

[0117] For a valid grid, obtain the random numbers of surrounding nodes and the growth probabilities of solid-phase growth nuclei of the valid grid in multiple directions. Take the directions in which the growth probabilities of the solid-phase growth nuclei of the valid grid are greater than the random numbers of the surrounding nodes as the growth directions, and take the adjacent grids located in the growth directions of the valid grid as the growth grids. Generate solid-phase particle nuclei at the coordinate positions corresponding to the growth grids in the digital model. Update the growth grids where the solid-phase particle nuclei are generated to valid grids, and calculate the porosity of the digital model. If the porosity of the digital model reaches the pre-mining porosity, end the direction growth calculation; otherwise, select the next valid grid to execute the direction growth calculation.

[0118] As the best embodiment of the present invention, a method for reconstructing surrounding rock fractures in three-dimensional simulation tests includes:

[0119] 1. Set up multiple high-definition camera devices at points inside the model on the simulation experiment platform. After the model device is stable, conduct simulated coal mining and collect images.

[0120] 2. Upload the collected images to the server, use binaryzation and edge detection methods to obtain the contour of the feature region of the original image, calculate the pixel coordinates of the center point of the region through positioning, segmentation, and decoding, and finally convert the difference of different pixel points into actual distances according to the scale to obtain the change value of the fracture.

[0121] 3. Display the fracture change data on the coordinate system in the order of the time axis, including the fracture length change diagram and the sudden change trend diagram. The length change diagram mainly shows the process of fracture change, while the sudden change trend diagram mainly presents the change amplitude during the process.

[0122] 4. After the coal mining process is completed, measure the porosity of the model. The distribution probability of solid-phase growth nuclei of each grid is obtained as P cd , and the given growth probabilities P di (i represents the direction, and the values are 1, 2, 3, 4, 5, 6, 7, 8 for each direction as shown in Figure 3 ).

[0123] 5. Divide the entire computational domain into multiple layers of grids, and generate a program using the four-parameter generation method (QSGS) with Matlab according to the flowchart shown in Figure 3 .

[0124] 4. The scatter plot command scatter in Matlab can be used to generate the image of the porous medium, process it to generate the geometric model format that can be read by the finite element software, generate the contour line of the solid phase particles through the contour line command in Matlab, and save the contour line data to a data file. Since there are many contour line points and a large amount of data, it is difficult to directly model using general finite element analysis software. Therefore, Auto CAD VBA programming is selected to realize the generation of the fracture model.

[0125] 7. Finally, select the file type ACIS (*.dxf) for output, import it into the finite element analysis software, and complete the reconstruction of the fracture.

[0126] 8. Use 3D printing technology to manufacture the obtained image into a solid and compare it with the original model to verify the accuracy of the three-dimensional reconstruction model in this time.

[0127] As Figure 4 shown in the schematic diagram of the hardware structure of an electronic device according to the present invention, it includes:

[0128] At least one processor 401; and,

[0129] A memory 402 communicatively connected to at least one of the processors 401; wherein,

[0130] The memory 402 stores instructions executable by at least one of the processors, and the instructions are executed by at least one of the processors, so that at least one of the processors can execute the method for surrounding rock fracture reconstruction in the three-dimensional simulation test as described above.

[0131] Figure 4 Taking one processor 401 as an example.

[0132] The electronic device may further include: an input device 403 and a display device 404.

[0133] The processor 401, the memory 402, the input device 403 and the display device 404 may be connected through a bus or other means. In the figure, it is taken as an example of being connected through a bus.

[0134] The memory 402, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs and modules, such as the program instructions / modules corresponding to the method for surrounding rock fracture reconstruction in the three-dimensional simulation test in the embodiments of the present application. For example, Figure 1 the method flow shown. The processor 401 executes various functional applications and data processing by running the non-volatile software programs, instructions and modules stored in the memory 402, that is, realizes the method for surrounding rock fracture reconstruction in the above embodiments.

[0135] The memory 402 may include a program storage area and a data storage area. The program storage area may store an operating system and application programs required for at least one function. The data storage area may store data created according to the use of the method for reconstructing surrounding rock fractures in three-dimensional simulation tests, etc. In addition, the memory 402 may include high-speed random access memory and may also include non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some embodiments, the memory 402 may optionally include a memory remotely disposed relative to the processor 401, and these remote memories may be connected to the device for executing the method for reconstructing surrounding rock fractures in three-dimensional simulation tests through a network. Examples of the above-mentioned network include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0136] The input device 403 may receive input user clicks and generate signal inputs related to user settings and function controls for the method for reconstructing surrounding rock fractures in three-dimensional simulation tests. The display device 404 may include a display screen and other display devices.

[0137] When the one or more modules are stored in the memory 402 and run by the one or more processors 401, they execute the method for reconstructing surrounding rock fractures in three-dimensional simulation tests in any of the above method embodiments.

[0138] The present invention combines the model parameters of a three-dimensional simulation model to establish a three-dimensional fracture model, realizes the reconstruction of the model, and finally uses 3D printing technology to manufacture an entity for comparison with the experimental model, solving the problems of low monitoring accuracy of the surrounding rock fracture field and inaccurate three-dimensional reconstruction model in three-dimensional simulation experiments. At the same time, by designing a marker point camera to transmit real-time images, the development and expansion of fractures are obtained, achieving the purpose of monitoring the surrounding rock fracture field in three-dimensional simulation tests.

[0139] An embodiment of the present invention provides a storage medium that stores computer instructions, and when a computer executes the computer instructions, it is used to execute all steps of the method for reconstructing surrounding rock fractures in three-dimensional simulation tests as described above.

[0140] The above-described embodiments merely represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A method for reconstructing surrounding rock fractures in a three-dimensional simulation test, characterized in that: include: Obtaining the porosity of the coal mining model after simulating coal mining in the three-dimensional simulation experiment as the porosity after coal mining; Obtaining the distribution probability of the solid phase growth nucleus obtained by statistics of each grid on the coal mining model, and the growth probability of the solid phase growth nucleus of each grid in multiple directions; Generate a digital model of post-coal mining fractures based on the post-coal mining porosity, the distribution probability of the solid phase growth nuclei of each grid, and the growth probability of the solid phase growth nuclei of each grid in multiple directions; Outputting the post-coal mining fracture digital model to a three-dimensional printing device, wherein the three-dimensional printing device reconstructs the post-coal mining fracture digital model into a fracture three-dimensional model; The method of generating a post-coal mining fracture digital model according to the post-coal mining porosity, the distribution probability of the solid phase growth nuclei of each grid, and the growth probability of the solid phase growth nuclei of each grid in multiple directions specifically includes: Building digital models based on grid coordinates; Traversing all the grids of the digital model, for each grid, obtaining a grid node random number and a distribution probability of a solid phase growth core of the grid, if the grid node random number is less than the distribution probability of a solid phase growth core of the grid, then generating a solid phase particle core at a corresponding coordinate position of the grid in the digital model, and the grid of the generated solid phase particle core is used as a valid grid; Performing directional growth calculation on each effective grid until the porosity of the digital model reaches the porosity after coal mining; forming contour equipotential lines based on the effective grid of the digital model, and generating a digital model of post-coal mining fractures based on the contour equipotential lines; The directional growth calculation specifically includes: For a valid grid, random numbers of surrounding nodes and growth probabilities of solid phase growth nuclei of the valid grid in multiple directions are obtained, the direction in which the growth probability of the solid phase growth nuclei of the valid grid is greater than the random numbers of surrounding nodes is taken as the growth direction, the adjacent grids located in the growth direction of the valid grid are taken as the growth grids, a solid phase particle kernel is generated at the corresponding coordinate position of the growth grid in the digital model, the growth grid of the generated solid phase particle kernel is updated to the valid grid, and the porosity of the digital model is calculated. If the porosity of the digital model reaches the porosity after coal mining, the directional growth calculation is terminated, otherwise the next valid grid is selected to execute the directional growth calculation.

2. The method for reconstructing surrounding rock fractures in a three-dimensional simulation test according to claim 1, characterized in that: The step of obtaining the porosity of the coal mining model after the simulated coal mining in the three-dimensional simulation experiment as the porosity after coal mining specifically includes: obtaining a post-coal mining model image of the coal mining model after the simulated coal mining in the three-dimensional simulation experiment, and calculating the porosity of the coal mining model after the simulated coal mining according to the post-coal mining model image as the porosity after coal mining; The method of obtaining the distribution probability of solid phase growth nuclei obtained by statistics for each grid on the coal mining model, and the growth probability of solid phase growth nuclei in multiple directions for each grid, specifically includes: dividing the model image after coal mining into multiple grids, and according to the image information of the model image after coal mining, counting the distribution probability of solid phase growth nuclei in each grid, and the growth probability of solid phase growth nuclei in multiple directions for each grid.

3. The method for reconstructing surrounding rock fractures in a three-dimensional simulation test according to claim 2, characterized in that: The acquisition of the post-coal mining model image of the coal mining model after simulating coal mining in the three-dimensional simulation experiment specifically includes: In the three-dimensional simulation experiment, images of the coal mining model after simulated coal mining taken by multiple cameras located in the coal mining model are obtained, and the images taken by the multiple cameras are fused to obtain the image of the model after coal mining.

4. The method for reconstructing surrounding rock fractures in a three-dimensional simulation test according to claim 3, characterized in that: Also includes: Identifying cracks from the model image after coal mining as cracks actually measured after coal mining, and calculating crack change values ​​of the cracks actually measured after coal mining as crack change values ​​actually measured after coal mining; Identifying a fracture from the post-coal mining fracture digital model as a fracture to be verified, and calculating a fracture change value to be verified of the fracture to be verified; The measured crack change value after coal mining is compared with the crack change value to be verified. If the difference between the measured crack change value after coal mining and the crack change value to be verified is less than the preset difference threshold, the digital model of the crack after coal mining is judged to be valid; otherwise, the digital model of the crack after coal mining is judged to be invalid. A new digital model of the crack after coal mining is generated based on the porosity after coal mining, the distribution probability of the solid phase growth nucleus of each grid, and the growth probability of the solid phase growth nucleus of each grid in multiple directions.

5. The method for reconstructing surrounding rock fractures in a three-dimensional simulation test according to claim 4, characterized in that: Also includes: obtaining the porosity of the coal mining model before coal mining as the porosity before coal mining; The coal mining model is divided into a plurality of grids, and the initial distribution probability of the solid phase growth nucleus of each grid and the initial growth probability of the solid phase growth nucleus of each grid in multiple directions are obtained; Generate an initial fracture digital model according to the porosity before coal mining, the initial distribution probability of the solid phase growth nucleus of each grid, and the initial growth probability of the solid phase growth nucleus of each grid in multiple directions; identifying a fracture from the initial fracture digital model as an initial fracture; The calculating the change value of the crack to be verified of the crack to be verified specifically includes: comparing the initial crack with the crack to be verified, and determining the change value of the crack to be verified.

6. The method for reconstructing surrounding rock fractures in a three-dimensional simulation test according to claim 5, characterized in that: Also includes: obtaining a pre-coal mining model image of a coal mining model before coal mining in a three-dimensional simulation experiment; identifying cracks from the pre-coal mining model image as pre-coal mining measured cracks; The calculating of the crack change value of the crack actually measured after coal mining as the crack change value actually measured after coal mining specifically includes: The cracks actually measured after coal mining are compared with the cracks actually measured before coal mining, and the crack change value of the cracks actually measured after coal mining is obtained as the crack change value actually measured after coal mining.

7. The method for reconstructing surrounding rock fractures in a three-dimensional simulation test according to claim 1, characterized in that: Also includes: Acquire a coal mining process model image of a coal mining model simulating a coal mining process in a three-dimensional simulation experiment; Cracks are identified from the coal mining process model image, and crack change data about the time axis is generated and displayed.

8. An electronic device, characterized in that: include: at least one processor; as well as, a memory communicatively connected to at least one of the processors; wherein, The memory stores instructions that can be executed by at least one of the processors, and the instructions are executed by at least one of the processors so that at least one of the processors can execute the method for reconstructing surrounding rock fractures in three-dimensional simulation tests as described in any one of claims 1 to 7.

9. A storage medium, characterized in that: The storage medium stores computer instructions, and when a computer executes the computer instructions, it is used to execute all steps of the method for reconstructing surrounding rock fractures in a three-dimensional simulation test as described in any one of claims 1 to 7.

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