Method, device and computer equipment for constructing three-dimensional fracture network rock model

Abstract

The present invention provides a method, device and computer equipment for constructing a three-dimensional fracture network rock model. The method includes: obtaining geometric information of multiple planes of the rock mass; obtaining intersection information of intersection segments formed by each plane intersecting with all other planes; adjusting each plane and each intersection line to a new position by rotation and translation; generating a first grid surface based on fractal theory, and using the first grid surface to perform grid fluctuation attenuation processing on multiple intersection segments of each plane to obtain multiple second grid surfaces; cutting each contour grid surface with the contour intersection line as the cutting line to obtain multiple contour fractal surfaces; adjusting multiple contour fractal surfaces and multiple joint grid surfaces back to their original positions by rotation and translation to obtain a rock model to be cut; cutting the rock model to be cut based on the internal intersection line to obtain multiple block models. The present invention uses the fractal theory principle to dynamically adjust the grid characteristics of the intersection area, solving the problem of difficult grid division of multiple fractal surfaces.

Description

Technical Field

[0001] The invention belongs to the technical field of rock mass model construction, and in particular relates to a method, a device and a computer equipment for constructing a three-dimensional fracture network rock mass model. Background Art

[0002] In the field of rock mechanics and engineering geology, the fracture network plays a decisive role in the mechanical properties and hydraulic characteristics of the rock mass. At present, the Discrete Fracture Network (DFN) model is often used to describe the distribution characteristics of fractures in the rock mass. However, the DFN model often assumes that these fractures are simple planar smooth geometric models, ignoring the roughness and three-dimensional complexity of the fractures, and cannot fully capture the mechanical intercalation effect between fractures and its impact on fracture expansion. Similarly, in fluid flow simulation, the roughness of the fractures and the complex connection paths will directly affect the permeability model and the migration process of the fluid in the fracture network.

[0003] Therefore, given that fracture characteristics are crucial to understanding and predicting the mechanical behavior of rock masses, the differences between the DFN model and the complex geometric conditions of rock masses in nature will greatly limit the accuracy of predictions of rock mass mechanics and fluid flow characteristics, especially for engineering applications that require accurate fracture descriptions, such as geotechnical stability analysis, hydrogeological assessment, and petroleum engineering simulations. Summary of the invention

[0004] The purpose of the present invention is to provide a method for constructing a three-dimensional fracture network rock model, which uses the fractal theory principle to dynamically adjust the grid characteristics of the intersection area and solves the problem of difficult grid division of multiple fractal surfaces.

[0005] To achieve the above-mentioned object, the present invention provides a method for constructing a three-dimensional fracture network rock model, wherein the rock mass includes a complete rock block and a plurality of joint fracture surfaces located in the rock block, the rock block is a polyhedral structure, and the joint fracture surfaces are polygonal structures, and the construction method includes the following steps: step S10, obtaining geometric information of a plurality of planes of the rock mass, wherein the geometric information of the planes includes the vertex coordinates of each vertex constituting the plane, and the plurality of planes include a plurality of the joint fracture surfaces and a plurality of contour surfaces surrounding the contour of the rock block; step S20, based on the geometric information of the plurality of planes, obtaining the coordinates of each plane; The intersection line segments are formed by the intersection of the contour surface and all other planes, and the intersection line information of each intersection line segment, the intersection line segment is divided into a contour intersection line formed by the intersection of two contour surfaces and an internal intersection line formed by the intersection of two non-contour surfaces, the intersection line information includes the three-dimensional coordinates of the two endpoints of the intersection line segment, the angle between the two planes corresponding to the intersection line segment, and the contour information Boolean value; step S30, respectively rotate and translate each plane and each intersection line segment, adjust each plane and each intersection line segment from the original position to a new position that meets the preset conditions, and obtain the Z coordinate value Z0 of each plane at the new position, wherein the full The preset condition is satisfied when the plane and the intersection line segment are parallel to the XOY plane and the X coordinate value and the Y coordinate value in the three-dimensional coordinates of the points on the plane and the intersection line segment are both greater than 0; step S40, based on the fractal theory, generating a rectangular first grid surface in the XOY plane according to the preset accuracy, the first grid surface includes a plurality of grid nodes, and the X coordinate value and the Y coordinate value of each grid node are both greater than 0; step S50, using the first grid surface to perform grid fluctuation attenuation processing on the plurality of intersection line segments of each plane to obtain a plurality of second grid surfaces including the intersection line segments, the number of the second grid surfaces is the same as the number of the planes, including Including multiple contour mesh surfaces corresponding to multiple contour surfaces one by one and multiple joint mesh surfaces corresponding to multiple joint fissure surfaces one by one; step S60, using the contour intersection line as the cutting line, cutting the multiple contour mesh surfaces respectively to obtain multiple contour fractal surfaces, and the multiple contour fractal surfaces correspond to the multiple contour surfaces one by one; step S70, based on rotation and translation operations, adjusting the multiple contour fractal surfaces and the multiple joint mesh surfaces from new positions back to original positions respectively, to obtain a rock model to be cut; step S80, cutting the rock model to be cut based on the internal intersection line to obtain multiple block models.

[0006] In a specific embodiment, the step of generating a rectangular first grid surface in the XOY plane according to a preset accuracy based on fractal theory includes: step (a), constructing a rectangular surface in the XOY plane of the three-dimensional coordinate system, and the X coordinate value and Y coordinate value of each point on the rectangular surface are greater than 0, the area of ​​the rectangular surface is greater than the area of ​​each plane, and the positive projection of each plane to the rectangular surface completely falls into the rectangular surface; step (b), dividing the rectangular surface into a plurality of rectangular grids with the same size according to the preset accuracy, and obtaining the X coordinate value and Y coordinate value of each grid node, wherein the preset accuracy includes: the ratio of the length of the rectangular grid to the length of the rectangular surface is 1: (10~100), and the ratio of the width of the rectangular grid to the width of the rectangular surface is 1: (10~100); step (c), calculating the first fluctuation value of each grid node based on a first formula, obtaining a fluctuation value set and an absolute value of a maximum fluctuation fluctuation value, wherein the fluctuation value set is composed of the first fluctuation values ​​of all grid nodes, and the absolute value of the maximum fluctuation fluctuation value is the value with the largest absolute value among all the first fluctuation values, and the first formula is:

[0007] ; Wherein, z is the first fluctuation value of the grid node; x is the X coordinate value of the grid node; y is the Y coordinate value of the grid node; L is the sample length; G is the fractal roughness; D is the fractal dimension; γ is the parameter of the frequency distribution; M is the number of superimposed rough peaks on the rough structure surface; n is the frequency, which is used for iteration during the simulation process; is the upper limit value, used to limit the highest roughness frequency; Ls is the cutoff length; is a random quadrant; step (d), based on the X coordinate value, Y coordinate value and Z coordinate value of each grid node, generating the first grid surface, wherein the Z coordinate value of the grid node is the first fluctuation value of the grid node.

[0008] In a specific embodiment, the upper limit The second formula is used for calculation, and the second formula is:

[0009] ; Where L is the sample length, Ls is the cutoff length, and γ is the parameter of the frequency distribution.

[0010] In a specific embodiment, the step of using the first grid surface to perform grid fluctuation attenuation processing on multiple intersection line segments of a plane to obtain a second grid surface containing the intersection line segments includes: using the first grid to perform grid fluctuation attenuation processing on each intersection line segment of the plane respectively, and obtaining multiple second fluctuation values ​​after attenuation processing of each grid node, and the multiple second fluctuation values ​​correspond to the multiple intersection line segments one by one; sorting the multiple second fluctuation values ​​of each grid node, and taking the smallest second fluctuation value as the target fluctuation value; based on the target fluctuation value of each grid node and the Z coordinate value Z0 of the plane, obtaining a new Z coordinate value of each grid node; based on the X coordinate value, Y coordinate value and new Z coordinate value of each grid node, determining the position of each grid node, and generating a second grid surface containing the intersection line segments.

[0011] In a specific embodiment, the step of performing grid fluctuation attenuation processing on an intersection line segment of a plane using the first grid surface to obtain a second fluctuation value after attenuation processing includes: step (1), based on the intersection line information of the plane intersection line segment and the absolute value of the maximum fluctuation fluctuation value of the first grid surface, calculating the attenuation range limit value corresponding to the intersection line segment according to a third formula, wherein the third formula is:

[0012] ;in, is the limit value of the attenuation range, z max is the absolute value of the maximum fluctuation value, is the angle between the two planes corresponding to the intersection line segment; step (2), based on the three-dimensional coordinates of each grid node and the intersection line information of the intersection line segment, obtain the distance d between each grid node and the intersection line segment; step (3), compare the distance d between each grid node and the intersection line segment with a preset threshold value respectively, when the distance d is less than or equal to the preset threshold value, the second fluctuation value of the grid node after attenuation processing is set to 0; step (4), compare the distance d between other grid nodes and the intersection line segment that have not been attenuated in step (3) with the attenuation range limit value, when the distance between other grid nodes and the intersection line segment is less than the attenuation range limit value, the second fluctuation value of the grid node is the fluctuation value z obtained by attenuation processing using the fourth formula rd , wherein the fourth formula is:

[0013] , is the limit value of the attenuation range, z max is the absolute value of the maximum fluctuation value, d is the distance between the grid node and the intersection line segment; when the distance between other grid nodes and the intersection line segment is greater than or equal to the attenuation range limit value, the second fluctuation value of the grid node is equal to the first fluctuation value.

[0014] In a specific embodiment, the step of obtaining the intersection line segment formed by the intersection of any two planes in step S20 includes: step (1), based on the geometric information of the first plane, obtaining the plane equation of the first plane and the straight line equations corresponding to the multiple first sides of the first plane; step (2), based on the geometric information of the second plane, obtaining the plane equation of the second plane and the straight line equations corresponding to the multiple second sides of the second plane; step (3), combining the plane equation of the first plane and the plane equation of the second plane to obtain the intersection line equation of the first plane and the second plane; step (4) Solve the intersection line equation and the straight line equation of each first side and the straight line equation of each second side respectively to obtain R intersection coordinates; step (5) arrange the R intersection coordinates based on the bubbling order to obtain a sequentially arranged intersection set, and connect them in order to obtain R-1 line segments; step (6) obtain the midpoints of the R-1 line segments respectively, and determine whether the midpoint of each line segment belongs to the range of both the first plane and the second plane, and take the line segment whose midpoint belongs to both the first plane and the second plane as the intersection line segment where the first plane and the second plane intersect.

[0015] In a specific embodiment, step S10 comprises: step (1), obtaining point cloud data of the rock mass by using an unmanned aerial vehicle (UAV) for aerial photography; step (2), obtaining geometric information of each contour surface of the rock block based on the point cloud data of the rock mass, wherein the geometric information of the contour surface includes the vertex coordinates of each vertex constituting the contour surface; step (3), identifying cracks and joint surfaces in different areas of the rock mass contour surface based on spatial clustering analysis of the point cloud data and density, and extracting joint data representing the rock mass structure by normal estimation and plane fitting method, wherein the joint data includes joint inclination and joint dip; step (4), constructing each joint fracture surface into a polygonal structure according to the exposure surface information, geological survey information and the joint data, and obtaining the geometric information of each joint fracture surface, wherein the geometric information of the joint fracture surface includes the vertex coordinates of each vertex constituting the joint fracture surface.

[0016] The present invention also provides a device for constructing a three-dimensional fracture network rock model, wherein the rock includes a complete rock block and a plurality of joint fracture surfaces located in the rock block, the rock block is a polyhedral structure, and the joint fracture surfaces are polygonal structures, and the construction device includes: a first acquisition module for acquiring geometric information of a plurality of planes of the rock body, wherein the geometric information of the planes includes vertex coordinates of each vertex constituting the planes, and the plurality of planes include a plurality of the joint fracture surfaces and a plurality of contour surfaces surrounding the contour of the rock block; and a second acquisition module for acquiring, based on the geometric information of the plurality of planes, the relationship between each plane and all other planes. A plurality of intersection line segments formed by the intersection, and the intersection line information of each intersection line segment, wherein the intersection line segment is divided into a contour intersection line formed by the intersection of two contour surfaces and an internal intersection line formed by the intersection of two contour surfaces, wherein the intersection line information includes the three-dimensional coordinates of the two endpoints of the intersection line segment, the angle between the two planes corresponding to the intersection line segment, and the contour information Boolean value; a first position adjustment module, used to rotate and translate each plane and each intersection line segment respectively, adjust each plane and each intersection line segment from the original position to a new position that meets the preset conditions, and obtain the Z coordinate value Z0 of each plane at the new position, wherein the preset conditions are met It means that the plane and the intersection line segment are parallel to the XOY plane, and the X coordinate value and the Y coordinate value in the three-dimensional coordinates of the points on the plane and the points on the intersection line segment are both greater than 0; a generating module is used to generate a rectangular first grid surface in the XOY plane according to a preset accuracy based on the fractal theory, the first grid surface includes a plurality of grid nodes, and the X coordinate value and the Y coordinate value of each grid node are both greater than 0; a processing module is used to use the first grid surface to perform grid fluctuation attenuation processing on the plurality of intersection line segments of each plane to obtain a plurality of second grid surfaces containing the intersection line segments, the number of the second grid surfaces is the same as the number of the planes, including the plurality of wheels A plurality of contour mesh surfaces corresponding one to one with the contour surfaces and a plurality of joint mesh surfaces corresponding one to one with the plurality of joint fissure surfaces; a cutting module, used to use the contour intersection line as the cutting line, and respectively cut the plurality of contour mesh surfaces to obtain a plurality of contour fractal surfaces, and the plurality of contour fractal surfaces correspond one to one with the plurality of contour surfaces; a second position adjustment module, used to adjust the plurality of contour fractal surfaces and the plurality of joint mesh surfaces from new positions back to original positions based on rotation and translation operations, to obtain a rock model to be cut; a third acquisition module, used to cut the rock model to be cut based on the internal intersection line, to obtain a plurality of block models.

[0017] The present invention further provides a computer device, comprising: a processor and a memory, wherein a computer program is stored in the memory, and when the processor executes the computer program, the computer device implements the method described above.

[0018] The present invention also provides a computer-readable storage medium. When instructions in the computer-readable storage medium are executed by a processor, the processor executes any of the methods described above.

[0019] The beneficial effects of the present invention include at least:

[0020] The present invention provides a method for constructing a three-dimensional fracture network rock model, and the method comprises the following steps: step S10, obtaining geometric information of multiple planes of the rock mass, wherein the geometric information of the planes comprises vertex coordinates of each vertex constituting the planes; step S20, based on the geometric information of the multiple planes, obtaining multiple intersection line segments formed by the intersection of each plane with all other planes, and intersection line information of each intersection line segment; step S30, respectively performing rotation and translation operations on each plane and each intersection line segment, adjusting each plane and each intersection line segment from an original position to a new position satisfying a preset condition, and obtaining a Z coordinate value Z0 of each plane at the new position; step S40, based on fractal theory, generating a rectangular first grid surface in an XOY plane according to a preset accuracy, wherein the first grid surface comprises multiple grid nodes, and the X coordinate value and the Y coordinate value of each grid node are both greater than 0; step S50, using the first grid surface to perform grid fluctuation attenuation processing on the multiple intersection line segments of each plane to obtain multiple second grid surfaces containing the intersection line segments; step S60, taking the contour intersection line as the cutting line, cutting the multiple contour grid surfaces respectively to obtain multiple contour fractal surfaces; step S70, based on the rotation and translation operations, adjusting the multiple contour fractal surfaces and the multiple joint grid surfaces from the new positions back to the original positions respectively, to obtain the rock model to be cut; step S80, cutting the rock model to be cut based on the internal intersection line to obtain multiple block models; the present invention aims at the problem that the grid division of the intersection of fractal surfaces is difficult to handle, and dynamically adjusts the grid characteristics of the intersection area by using the fractal theory principle, specifically, based on the distance between the grid node and the intersection line, the grid fluctuation degree of the part near the intersection line is proportionally attenuated, and reducing the fluctuation degree means that in the complex area where two fractal surfaces intersect, the consistency and feasibility of the grid division can be ensured by reducing the strength of the fractal feature. In this way, on the one hand, it greatly simplifies the complex processing work required for processing highly irregular grids near the intersection line in the past, and on the other hand, it also retains the authenticity and accuracy of the fractal characteristics of the area far away from the intersection line, and retains the fractal characteristics to the greatest extent.

[0021] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the steps of a method for constructing a three-dimensional fracture network rock model provided by an embodiment of the present invention;

[0023] Figure 2 A three-dimensional model diagram constructed for the present invention, wherein: Figure 2 (a) is a three-dimensional model diagram of a rock block constructed by the present invention, Figure 2 (b) is a three-dimensional model diagram of multiple joint fissure surfaces constructed by the present invention, Figure 2 (c) a three-dimensional model diagram of the rock mass constructed by the present invention;

[0024] Figure 3 This is an example diagram of the rotation and translation operations in step S30 of the present invention;

[0025] Figure 4 The rectangular first grid map generated in step S40 of the present invention;

[0026] Figure 5 This is a comparison diagram of two joint fracture surfaces without and with grid wave attenuation processing, where: Figure 5 (a) is the three-dimensional structure diagram of two joint crack surfaces without attenuation treatment. Figure 5 (b) is a three-dimensional structural diagram of two joint crack surfaces that have been subjected to attenuation treatment;

[0027] Figure 6 for Figure 5 The structural diagram of two joint crack surfaces at different states is shown in Figure 1, where: Figure 6 (a) Figure 5 (a) shows a schematic diagram of the structure of two joint crack surfaces at an angle without attenuation treatment. Figure 6 (b) Figure 5 (b) is a schematic diagram of the structure of two joint crack surfaces at an angle for attenuation treatment;

[0028] Figure 7 for Figure 5 The structural schematic diagram of the intersection position of two joint crack surfaces in different states is shown in FIG. Figure 7 (a) Figure 5 (a) shows the structural diagram of the intersection of two joint crack surfaces without attenuation treatment. Figure 7 (b) Figure 5 (b) Structural schematic diagram of the intersection position of two joint fissure surfaces subjected to attenuation treatment;

[0029] Figure 8 This is a comparison diagram of the contour mesh surface before and after cutting provided by the present invention, wherein: Figure 8 (a) is the contour mesh surface diagram including the intersection line segment before cutting. Figure 8 (b) The contour fractal surface image obtained after cutting along the contour intersection line;

[0030] Fig. 9 A rock model diagram to be cut obtained by adjusting a plurality of contour fractal surfaces and a plurality of joint mesh surfaces from new positions back to original positions;

[0031] Fig.10 These are multiple rock model images obtained after cutting;

[0032] Fig.11 A module diagram of a device for constructing a three-dimensional fracture network rock model provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0034] Please refer to Figure 1 The present invention provides a method for constructing a three-dimensional fracture network rock model, wherein the rock includes a complete rock block and a plurality of joint fracture surfaces located in the rock block, the rock block is a polyhedral structure, and the joint fracture surfaces are polygonal structures. The construction method includes the following steps:

[0035] Step S10, obtaining geometric information of multiple planes of the rock mass, wherein the geometric information of the planes includes vertex coordinates of each vertex constituting the planes, and the multiple planes include multiple contour surfaces and multiple joint and fissure surfaces that enclose the contour of the rock block.

[0036] In the present invention, the joint fissure surface may be set to penetrate the rock block or may not penetrate the rock block.

[0037] In one embodiment of the present invention, the geometric information of the rock block and the geometric information of the joints and fissures are both acquired based on point cloud data of the actual rock mass. In another embodiment of the present invention, the geometric information of the rock mass and the geometric information of the joints and fissures can also be acquired based on a constructed three-dimensional model of the rock mass. The three-dimensional model of the rock mass is a simplified model of the three-dimensional model of the actual rock mass, which can be understood as simplifying the irregular contour structure of the rock block into a regular rectangular shape, and simplifying the polygonal structure of the joints and fissures into a rectangle.

[0038] In a specific implementation, the step S10 includes:

[0039] Step (1): Use drone aerial photography to obtain point cloud data of the rock mass.

[0040] In the present invention, the point cloud data is high-density point data, including rich spatial information of the rock mass contour surface, and is obtained through a multi-view image three-dimensional reconstruction method.

[0041] Preferably, when using a drone to obtain an image of the actual rock mass, the drone needs to be close to the wall for shooting. The wall-closed aerial photography means that when the drone obtains the image of the rock mass, the distance between it and the rock mass is between 15m and 25m, specifically 15m, 18m, 20m, 22m and 25m, etc.

[0042] Preferably, the drone is a DJI Mavic Pro series portable drone with a maximum flight altitude of 500m, a maximum flight range of 5km, and a cumulative flight time of 2.5 hours; the drone is equipped with a gimbal bracket and a 4K resolution camera at the bottom, which can realize high-definition video and high-resolution full-spectrum aerial image acquisition.

[0043] Step (2): acquiring geometric information of each contour surface of the rock block based on the point cloud data of the rock mass, wherein the geometric information of the contour surface includes vertex coordinates of each vertex constituting the contour surface.

[0044] For ease of understanding, for example, when the contour surface is a hexagonal surface, the geometric information of the contour surface includes the vertex coordinates of six vertices, and when the contour surface is a quadrilateral surface, the geometric information of the contour surface includes the vertex coordinates of four vertices.

[0045] In the present invention, the vertex coordinates are three-dimensional coordinates.

[0046] Step (3), based on the spatial cluster analysis of the point cloud data and density, identify the cracks and joint surfaces in different areas of the rock mass contour surface, and extract joint data representing the rock mass structure through normal estimation and plane fitting method, wherein the joint data includes joint dip angle and joint inclination.

[0047] In the present invention, the plane fitting method is the least square method.

[0048] Step (4), constructing each joint fracture surface into a polygonal structure according to the exposure surface information, geological survey information and the joint data, and obtaining geometric information of each joint fracture surface, wherein the geometric information of the joint fracture surface includes the vertex coordinates of each vertex constituting the joint fracture surface.

[0049] In another specific implementation, the step S10 may further include:

[0050] Step (1), constructing a right-handed coordinate system, and constructing a simplified rock model based on the size information and joint information of the actual rock mass, wherein the simplified rock model includes a rectangular rock mass and a plurality of rectangular joint fracture surfaces, and the joint information includes joint position, joint length, joint dip, and joint inclination.

[0051] Step (2), based on the simplified rock mass model, obtain the geometric information of each contour surface of the rock block and the geometric information of each joint and fissure surface, wherein the geometric information of the contour surface includes the vertex coordinates of each vertex constituting the contour surface, and the geometric information of the joint and fissure surface includes the vertex coordinates of each vertex constituting the joint and fissure surface.

[0052] For example, in the present invention, the technical solution of the present invention is further described in detail based on a simplified rock model constructed to facilitate understanding.

[0053] Please refer to Figure 2 , Figure 2 (a) is a three-dimensional model diagram of a rock block constructed by the present invention, Figure 2 (b) is a three-dimensional model diagram of multiple joint fissure surfaces constructed by the present invention, Figure 2 (c) is a three-dimensional model diagram of a rock mass constructed by the present invention. In this embodiment, the rock mass model 10 constructed by the present invention includes a cubic rock block 11 and three rectangular joint fracture surfaces 12, the rock block 11 includes six contour surfaces, and the rock mass model 10 includes a total of 9 planes, which are composed of 6 contour surfaces and 3 joint fracture surfaces.

[0054] Correspondingly, the geometric information of the multiple planes of the rock mass includes vertex coordinates of four vertices of six contour surfaces and vertex coordinates of four vertices of three joint fracture surfaces.

[0055] Step S20, based on the geometric information of each plane, obtain multiple intersection line segments formed by the intersection of each plane with all other planes, and the intersection line information of each intersection line segment, the intersection line segments are divided into contour intersection lines formed by the intersection of two contour surfaces and internal intersection lines formed by non-intersection of two contour surfaces, the intersection line information includes the three-dimensional coordinates of the two endpoints of the intersection line, the angle between the two planes corresponding to the intersection line segment, and the contour information Boolean value.

[0056] The rock model constructed based on the present invention is explained. The present invention includes 9 planes in total, namely plane 1, plane 2, plane 3, plane 4, plane 5, plane 6, plane 7, plane 8 and plane 9, wherein plane 1 to plane 6 are contour planes, plane 7 to plane 9 are joint and fissure planes, and obtaining multiple intersection line segments formed by the intersection of each plane with all other planes can be understood as: obtaining the intersection line segments of plane 1 with planes 2 to plane 9 respectively, obtaining the intersection line segments of plane 2 with plane 1 and plane 3 to plane 9, obtaining the intersection line segments of plane 3 with planes 1 to plane 2, and plane 4 to plane 9... and so on, which will not be repeated.

[0057] For ease of understanding, an example is given based on the rock mass model and Figure 2From the perspective of angle of view, there are 5 intersection line segments between the upper surface of the rock block model and other planes, 4 of which are contour intersection lines and the other one is an internal intersection line. There are 6 intersection line segments between the right surface of the rock block model and other planes, 4 of which are contour intersection lines and the other two are internal intersection lines.

[0058] In the present invention, non-intersection of two contour surfaces means that a contour surface intersects a joint fissure surface or a joint fissure surface intersects another joint fissure surface.

[0059] In the present invention, the two planes corresponding to the intersection line can be understood as two planes simultaneously including the intersection line, that is, the intersection line is the intersection line of the two planes.

[0060] In the present invention, the angle between two planes is the angle between the normals of the two planes.

[0061] In the present invention, when the angle between the two planes is not 90 degrees, the angle between the two planes corresponding to the intersection segment is an acute angle.

[0062] In the present invention, when the two planes corresponding to the intersection line both belong to the contour surface, the contour information Boolean value is true; when one of the two planes corresponding to the intersection line does not belong to the contour surface or both planes do not belong to the contour surface, the contour information Boolean value is false.

[0063] In the present invention, after acquiring and storing data, the intersection information of multiple intersection line segments of each plane can be formed into an intersection line information set. When the total number of planes is 9, the number of intersection line information sets is 9; when the number of intersection line segments of a plane is 5, the intersection line information set includes the intersection line information of 5 intersection line segments.

[0064] The steps of obtaining the intersection line segment formed by the intersection of any two planes include:

[0065] Step (1): based on the geometric information of the first plane, obtain the plane equation of the first plane and the straight line equations corresponding to the first sides of the first plane.

[0066] Step (2): based on the geometric information of the second plane, obtain the plane equation of the second plane and the straight line equations corresponding to the plurality of second sides of the second plane.

[0067] In the present invention, the plane equation in the space rectangular coordinate system is , substituting the vertex coordinates of the three vertices in the plane into the equation, the coefficients in the plane equation can be determined.

[0068] In the present invention, the straight line equation of an edge is obtained based on the coordinates of two vertices on the edge.

[0069] It should be noted that the methods for obtaining the plane equation and the line equation are both existing technologies and are not described in detail here.

[0070] Step (3), solving the plane equation of the first plane and the plane equation of the second plane together to obtain the intersection equation of the first plane and the second plane.

[0071] Step (4): Solve the intersection equation of the first plane and the second plane together with the straight line equation of each first side and the straight line equation of each second side to obtain R intersection coordinates.

[0072] Step (5), arranging the coordinates of the R intersection points based on the bubbling order to obtain a sequentially arranged intersection point set, and connecting them in order to obtain R-1 line segments.

[0073] In the present invention, the purpose of bubble sort is to sort the intersections according to certain rules, from left to right, or from right to left, or clockwise or counterclockwise, so that when R-1 line segments are formed, each intersection can form a line segment with the adjacent intersections. It can also be understood that each intersection is connected in sequence to form R-1 line segments.

[0074] Step (6): obtain the midpoints of R-1 line segments respectively, and determine whether the midpoint of each line segment is within the range of both the first plane and the second plane, and take the line segment whose midpoint is within the range of both the first plane and the second plane as the intersection line segment.

[0075] In the present invention, when the midpoint of a line segment is within the range of both the first plane and the second plane, it is indicated that the line segment is a valid intersection line segment and is then used as an intersection line segment.

[0076] In the present invention, the intersection line of two planes may be one, two or more.

[0077] Step S30, respectively rotate and translate each plane and each intersection line segment, adjust each plane and each intersection line segment from the original position to a new position that meets a preset condition, and obtain the Z coordinate value Z0 of each plane at the new position, wherein satisfying the preset condition means that the plane and the intersection line segment are parallel to the XOY plane and the X coordinate value and the Y coordinate value in the three-dimensional coordinates of the point on the plane and the point on the intersection line segment are both greater than 0.

[0078] It should be noted that after each plane and each intersection line segment are rotated and translated respectively, the positional relationship between the intersection line segment and the plane remains unchanged. For ease of understanding, for example, if the first intersection line segment is the intersection line segment of plane 1 and plane 2, after completing the rotation and translation operations, the first intersection line segment is still the intersection line segment of plane 1 and plane 2, and the position of the first intersection line segment in plane 1 and plane 2 remains unchanged.

[0079] See also Figure 3 , Figure 3 This is an example of a plane rotation and translation operation.

[0080] Step S40: Based on fractal theory, a rectangular first grid surface is generated in the XOY plane according to a preset accuracy, wherein the first grid surface includes a plurality of grid nodes, and an X coordinate value and a Y coordinate value of each grid node are both greater than 0.

[0081] The step of generating a rectangular first grid surface in the XOY plane according to a preset accuracy based on fractal theory includes:

[0082] Step (a), constructing a rectangular surface in the XOY plane of the three-dimensional coordinate system, wherein the X coordinate value and the Y coordinate value of each point on the rectangular surface are both greater than 0, the area of ​​the rectangular surface is greater than the area of ​​each plane, and the orthographic projection of each plane onto the rectangular surface completely falls within the rectangular surface.

[0083] Step (b), dividing the rectangular surface into a plurality of rectangular grids of the same size according to the preset accuracy, and obtaining the X coordinate value and the Y coordinate value of each grid node.

[0084] Preferably, the preset accuracy includes: a ratio of a length Pr1 of the rectangular grid to a length of the rectangular surface is 1:(10-100), and a ratio of a width Pr2 of the rectangular grid to a width of the rectangular surface is 1:(10-100).

[0085] The fractal grid surface is designed to better reflect the real joint surface information. The higher the grid accuracy, the more realistically it can reflect the joint insertion effect and stress-strain conditions, and can better capture the small-scale microscopic rock mechanical behavior.

[0086] Preferably, the rectangular surface is a square, and the rectangular grid is a square grid.

[0087] Step (c), calculating the first fluctuation value of each grid node based on the first formula, obtaining a fluctuation value set and an absolute value of a maximum fluctuation fluctuation value, wherein the fluctuation value set is composed of the first fluctuation values ​​of all grid nodes, and the absolute value of the maximum fluctuation fluctuation value is the value with the largest absolute value among all the first fluctuation values.

[0088] The first formula is:

[0089] .

[0090] Preferably, the upper limit value The second formula is used for calculation, and the second formula is:

[0091] .

[0092] The meanings of the symbols in the first and second formulas are as follows: z is the first fluctuation value of the grid node; x is the X coordinate value of the grid node; y is the Y coordinate value of the grid node; L is the sample length; G is the fractal roughness; D is the fractal dimension; γ is the parameter of the frequency distribution; M is the number of rough peaks superimposed on the rough structure surface; n is the frequency, which is used for iteration during the simulation process; is the upper limit value, used to limit the highest roughness frequency; Ls is the cutoff length; The random quadrant.

[0093] It can be understood that the first fluctuation value of the grid node is the height of the grid node, and is also the Z coordinate value of the grid node.

[0094] In the present invention, L is a scale defining the simulation size, and its value is 10; G is a value greater than 0, which is used to control the degree of surface roughness; D is between 2 and 3, and this value can affect the frequency of surface roughness; γ is a value greater than 1, which is used to control the distribution of frequency, and Ls is used to limit the size of the highest roughness frequency; Distributed in [0, 2π], adding randomness to the entire graph.

[0095] In the present invention, the fractal dimension D affects the frequency of the surface roughness. A higher fractal dimension will reduce the waviness of the rough surface. The fractal roughness G affects the amplitude of the rough surface. When the G value is increased, the maximum value of the rough surface increases. The preset accuracy determines the number of grids, which in turn determines the complexity of the rough surface. It is worth noting that when the preset accuracy is 1, the three-dimensional WM surface will become a smooth plane, which provides the possibility of generating rough and smooth surfaces at the same time. Parameters is a frequency index, indicating the highest frequency of the sample. The parameter M indicates the number of superimposed ridges used to construct the surface, while the parameter D represents the fractal dimension of the surface, affecting the morphological characteristics of the surface. Increasing the value of D will make the surface morphology smoother and increase the amplitude ratio of high-frequency and low-frequency components.

[0096] Step (d), generating the first mesh surface based on the X coordinate value, Y coordinate value and Z coordinate value of each mesh node, wherein the Z coordinate value of the mesh node is the first fluctuation value of the mesh node.

[0097] The first rectangular grid surface generated by the present invention based on fractal theory is as follows Figure 4 shown.

[0098] Step S50, using the first grid surface to perform grid fluctuation attenuation processing on the multiple intersection segments of each plane to obtain multiple second grid surfaces containing the intersection segments, the number of the second grid surfaces is the same as the number of the planes, including multiple contour grid surfaces corresponding one-to-one to the multiple contour surfaces and multiple joint grid surfaces corresponding one-to-one to the multiple joint and fissure surfaces.

[0099] Preferably, the step of performing mesh fluctuation attenuation processing on a plurality of intersection line segments of a plane using the first mesh surface to obtain a second mesh surface including the intersection line segments comprises:

[0100] Step (1), using the first grid to perform grid fluctuation attenuation processing on each intersection line segment of the plane, and obtaining multiple second fluctuation values ​​after attenuation processing of each grid node, wherein the multiple second fluctuation values ​​correspond one-to-one to the multiple intersection line segments.

[0101] This step can be understood as using the first grid to perform grid fluctuation attenuation processing on an intersection line segment of the plane, and obtaining a second fluctuation value corresponding to the intersection line segment. Assuming that the number of intersection line segments of Plane 1 is 5, then using the first grid to perform grid fluctuation attenuation processing on the 5 intersection line segments in Plane 1, 5 second fluctuation values ​​will be obtained.

[0102] Step (2): sorting the plurality of second fluctuation values ​​of each grid node, and taking the smallest second fluctuation value as the target fluctuation value.

[0103] Step (3): based on the target undulation value of each grid node and the Z coordinate value Z0 of the plane, a new Z coordinate value of each grid node is obtained.

[0104] In the present invention, the new Z coordinate value=target undulation value+Z0.

[0105] Step (4): based on the X coordinate value, Y coordinate value and new Z coordinate value of each mesh node, determine the position of each mesh node and generate a second mesh surface containing the intersection line segment.

[0106] This step changes the height of each grid node based on the grid node's new Z coordinate value.

[0107] Preferably, the step of performing grid fluctuation attenuation processing on an intersection line segment of a plane using the first grid surface to obtain a second fluctuation value after attenuation processing comprises:

[0108] Step (1), based on the intersection line information of the plane intersection line segment and the absolute value of the maximum fluctuation value of the first grid surface, the attenuation range limit value corresponding to the intersection line segment is calculated according to the third formula, and the third formula is:

[0109] ;in, is the limit value of the attenuation range, z max is the absolute value of the maximum fluctuation value, is the angle between the two planes corresponding to the intersection segment.

[0110] Step (2): based on the three-dimensional coordinates of each grid node and the intersection line information of the intersection line segment, obtain the distance d between each grid node and the intersection line segment.

[0111] Step (3): compare the distance d between each grid node and the intersection line segment with a preset threshold value. When the distance d is less than or equal to the preset threshold value, the second fluctuation value after attenuation processing of the grid node is set to 0.

[0112] Step (4), comparing the distance d between other grid nodes and the intersection line segment that have not been attenuated in step (3) with the attenuation range limit value. When the distance between other grid nodes and the intersection line segment is less than the attenuation range limit value, the second fluctuation value of the grid node is the fluctuation value z obtained by attenuation processing using the fourth formula rd , wherein the fourth formula is:

[0113] , is the limit value of the attenuation range, z max is the absolute value of the maximum fluctuation value, d is the distance between the grid node and the intersection line segment; when the distance between other grid nodes and the intersection line segment is greater than or equal to the attenuation range limit value, the second fluctuation value of the grid node is equal to the first fluctuation value.

[0114] Preferably, the preset threshold is related to the preset accuracy.

[0115] More preferably, the preset threshold value= .

[0116] The preset threshold may also be set based on demand.

[0117] In the present invention, the relationship between the distance between the grid node and the intersection line segment and the preset threshold is first determined, and then the relationship between the distance and the attenuation range limit value is determined.

[0118] See also Figures 5 to 7 , Figure 5 (a) is the three-dimensional structure diagram of two joint crack surfaces without attenuation treatment. Figure 5 (b) is a three-dimensional structural diagram of two joint crack surfaces that have been subjected to attenuation treatment; Figure 6 (a) Figure 5 (a) shows a schematic diagram of the structure of two joint crack surfaces at an angle without attenuation treatment. Figure 6 (b) Figure 5(b) is a schematic diagram of the structure of two joint crack surfaces at an angle for attenuation treatment; Figure 7 (a) Figure 5 (a) shows the structural diagram of the intersection of two joint crack surfaces without attenuation treatment. Figure 7 (b) Figure 5 (b) Schematic diagram of the structure of the intersection of two joint fissure surfaces undergoing attenuation treatment.

[0119] Will Figure 6 (a) with Figure 6 By comparing (b), it can be seen that the meshes of the two joints and fissures without attenuation overlap each other near the intersection line, and the meshes of the two joints and fissures after attenuation are regularly reduced on both sides of the intersection line, retaining the fractal characteristics while achieving the unchanged intersection line. Figure 7 (a) with Figure 7 (b) By comparison, we can observe Figure 7 There is obvious grid overlap in (a). Figure 7 (b) The grid near the intersection line is neat and simple, and is easy to distinguish and process.

[0120] Step S60: Using the contour intersection line as a cutting line, the plurality of contour mesh surfaces are cut respectively to obtain a plurality of contour fractal surfaces, wherein the plurality of contour fractal surfaces correspond to the plurality of contour surfaces one by one.

[0121] See also Figure 8 , Figure 8 (a) is the contour mesh surface before cutting. Figure 8 (b) is the contour fractal surface obtained after cutting along the contour intersection line.

[0122] Based on the rock mass model provided by the present invention, the number of contour surfaces is 6, and correspondingly, the number of contour mesh surfaces is 6, and the number of contour fractal surfaces obtained after cutting is also 6.

[0123] Step S70: Based on the rotation and translation operations, the multiple contour fractal surfaces and the multiple joint mesh surfaces are respectively adjusted from the new positions back to the original positions to obtain a rock model to be cut.

[0124] It should be noted that the contour mesh surface, the contour fractal surface and the joint mesh surface are all fractal mesh surfaces.

[0125] In the present invention, the original position can be understood as the position of the contour surface and the crack surface before the rotation and translation operations of step S30 are performed.

[0126] For ease of understanding, an example is given, assuming that the relevant parameters for rotating and translating the plane in step S30 are: vertical rotation beta1, horizontal rotation beta2, and translation distance d; then this step translates -d, horizontal rotation -beta2, and vertical rotation -beta1.

[0127] See also Fig. 9 , Fig. 9 Correspondingly, the rock mass model to be cut is obtained by adjusting the multiple contour fractal surfaces and the multiple joint grid surfaces from the new positions back to the original positions.

[0128] Step S80: cutting the rock model to be cut based on the internal intersection lines to obtain a plurality of block models.

[0129] In the present invention, multiple block models, namely the three-dimensional fracture network rock model constructed by the present invention, are subsequently used as a whole for simulation research.

[0130] See also Fig.10 , Fig.10 These are the multiple block models obtained after cutting, such as Fig.10 As shown, there are 5 blocks, one of which (the largest block) contains unpenetrated joints and multiple unpenetrated joints.

[0131] This method preserves non-penetrating joints during the processing and calculation process. Therefore, in the subsequent simulation process, not only can the penetrating joints, that is, the connection relationship between blocks, be assigned: setting the corresponding mechanical parameters, but also the parameters of the cracks inside the blocks can be assigned. For example, the mechanical model of the contact surface uses the Mohr-Coulomb theorem. The cohesion between blocks can be set to 0 as needed, and a cohesion greater than 0 can be set on the non-penetrating joint surface inside the block to reflect different mechanical characteristics, so that all rock damage can be truly considered in a controllable manner.

[0132] The present invention innovatively provides a new technology for processing plane intersections, which makes the grid arrangement of these complex intersections orderly, effectively simplifies the complexity of subsequent discrete element simulation or analysis, and greatly improves the practicability of the model.

[0133] Regarding the subsequent simulation analysis, the explanation of parameter assignment: According to the constructed model, the rock mass is divided into b_sum blocks, b_sum{b1, b2, b3, ...}, each block bi stores grid information {original rock mass contour surface set {A}, original joint contour surface set {B}, block internal joint surface set {C}}, according to the different parts, according to the rock mass type, exploration data, etc., different parameters A{a1, a2, a3}, B{b1, b2, b3}, C{c1, c2, c3} are assigned to the three parts respectively. The mechanical behavior of the rock mass is simulated by the discrete element method.

[0134] See also Fig.11The present invention also provides a device 100 for constructing a three-dimensional fracture network rock model, wherein the rock includes a complete rock block and a plurality of joint fracture surfaces located in the rock block, the rock block is a polyhedral structure, and the joint fracture surfaces are polygonal structures. The construction device 100 includes: a first acquisition module 101, for acquiring geometric information of a plurality of planes of the rock mass, wherein the geometric information of the planes includes vertex coordinates of each vertex constituting the planes, and the plurality of planes include a plurality of the joint fracture surfaces and a plurality of contour surfaces surrounding the contour of the rock block; a second acquisition module 102, for acquiring the geometric information of each plane and the fracture network model based on the geometric information of the plurality of planes; The plurality of intersection line segments formed by the intersection of all other planes, and the intersection line information of each intersection line segment, wherein the intersection line segment is divided into a contour intersection line formed by the intersection of two contour surfaces and an internal intersection line formed by the intersection of two non-contour surfaces, and the intersection line information includes the three-dimensional coordinates of the two end points of the intersection line segment, the angle between the two planes corresponding to the intersection line segment, and the contour information Boolean value; the first position adjustment module 103 is used to rotate and translate each plane and each intersection line segment respectively, adjust each plane and each intersection line segment from the original position to a new position that meets the preset conditions, and obtain the Z coordinate value Z0 of each plane at the new position, wherein the preset conditions are met The component refers to that the plane and the intersection line segment are parallel to the XOY plane, and the X coordinate value and the Y coordinate value of the three-dimensional coordinates of the point on the plane and the point on the intersection line segment are both greater than 0; the generation module 104 is used to generate a rectangular first grid surface in the XOY plane according to a preset accuracy based on the fractal theory, the first grid surface includes a plurality of grid nodes, and the X coordinate value and the Y coordinate value of each grid node are both greater than 0; the processing module 105 is used to use the first grid surface to perform grid fluctuation attenuation processing on the plurality of intersection line segments of each plane to obtain a plurality of second grid surfaces containing the intersection line segments, the number of the second grid surfaces is the same as the number of the planes, including the plurality of contours A plurality of contour mesh surfaces corresponding to each other one by one and a plurality of joint mesh surfaces corresponding to each other one by one with respect to each of the joint and fissure surfaces; a cutting module 106, used for taking the contour intersection line as the cutting line, respectively cutting the plurality of contour mesh surfaces to obtain a plurality of contour fractal surfaces, and the plurality of contour fractal surfaces correspond to each other one by one with respect to the plurality of contour surfaces; a second position adjustment module 107, used for adjusting the plurality of contour fractal surfaces and the plurality of joint mesh surfaces from the new positions back to the original positions respectively based on rotation and translation operations, to obtain a rock model to be cut; a third acquisition module 108, cutting the rock model to be cut based on the internal intersection line, to obtain a plurality of block models.

[0135] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described devices and modules can refer to the contents of the aforementioned method embodiments and will not be repeated here.

[0136] The present invention also provides a computer device, Fig.11The construction device shown can be arranged in the computer device. The computer device includes a multimedia component, a memory, a processor, a communication interface and a bus. The memory, the processor and the communication interface are connected to each other through the bus. In addition, the computer device may include multiple processors so that the functions of the above-mentioned different modules can be realized by different processors.

[0137] The processor is used to control the overall operation of the device for constructing a three-dimensional fracture network rock model to complete all or part of the steps in the above-mentioned method for constructing a three-dimensional fracture network rock model.

[0138] The memory is used to store various types of data to support the operation of the device for constructing the three-dimensional fracture network rock model, and the stored data includes instructions for any application or method used to operate on the device for constructing the three-dimensional fracture network rock model, and application-related data, such as contact data, sent and received messages, pictures, audio, video, etc. The memory includes any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0139] The multimedia component includes a screen and an audio component. The screen is preferably a touch screen, and the audio component is used to output and / or input audio signals. For example, the audio component includes a microphone, which is used to receive external audio signals. The received audio signal is further stored in a memory or sent through a communication component. The audio component also includes at least one speaker for outputting audio signals. The I / O interface provides an interface between the processor and other interface modules, and the above-mentioned other interface modules include a keyboard, a mouse, and a button. The button is a virtual button or a physical button. The communication component is used for wired or wireless communication between the construction device of the three-dimensional fracture network rock model and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G or 4G, or a combination of one or more of them, so the corresponding communication component includes: Wi-Fi module, Bluetooth module, NFC module.

[0140] The communication interface uses a transceiver module such as, but not limited to, a transceiver to realize communication between the computer device and other devices or a communication network. For example, the communication interface can be any one or any combination of the following devices: a network interface (such as an Ethernet interface), a wireless network card, and other devices with network access functions.

[0141] A bus may include a pathway that transfers information between various components of a computer device (eg, memory, processor, communication interface).

[0142] A communication path is established between each of the above-mentioned computer devices through a communication network. Each computer device is used to implement part of the functions of the construction method provided in the embodiment of the present application. Any computer device can be a computer device (e.g., a server) in a cloud data center, or a computer device in an edge data center, etc.

[0143] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product providing the data synchronization cloud service includes one or more computer instructions, and when these computer program instructions are loaded and executed on a computer device, the process or function of the construction method provided in the embodiment of the present application is implemented in whole or in part.

[0144] The computer device may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. Computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired means such as coaxial cable, optical fiber, digital subscriber line, or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium stores computer program instructions for providing data synchronization cloud services.

[0145] Optionally, the construction device of the three-dimensional fracture network rock model can be implemented by one or more application specific integrated circuits (Application Specific Integrated Circuit, referred to as ASIC), digital signal processors (Digital Signal Processor, referred to as DSP), digital signal processing devices (Digital Signal Processing Device, referred to as DSPD), programmable logic devices (Programmable Logic Device, referred to as PLD), field programmable gate arrays (Field Programmable Gate Array, referred to as FPGA), controllers, microcontrollers, microprocessors or other electronic components, and is used to execute the above-mentioned three-dimensional fracture network rock model construction method.

[0146] This embodiment also provides a readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps in the method for constructing a three-dimensional fracture network rock model are implemented.

[0147] The readable storage medium is a readable storage medium that can store program codes, specifically a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0148] The embodiment of the present application also provides a computer program product comprising instructions, and when the computer program product is run on a computer, the computer executes the construction method provided by the embodiment of the present application.

[0149] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware or by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0150] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions and substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A method for constructing a three-dimensional fracture network rock mass model, wherein the rock mass comprises a complete rock block and a plurality of joint fracture surfaces located in the rock block, the rock block is a polyhedral structure, and the joint fracture surfaces are polygonal structures, characterized in that: The construction method comprises the following steps: Step S10, obtaining geometric information of a plurality of planes of the rock mass, wherein the geometric information of the planes includes vertex coordinates of each vertex constituting the planes, and the plurality of planes include a plurality of joint fracture surfaces and a plurality of contour surfaces surrounding the contour of the rock block; Step S20, based on the geometric information of the multiple planes, obtaining multiple intersection line segments formed by the intersection of each plane with all other planes, and the intersection line information of each intersection line segment, wherein the intersection line segment is divided into a contour intersection line formed by the intersection of two contour surfaces and an internal intersection line formed by the intersection of two contour surfaces, and the intersection line information includes the three-dimensional coordinates of the two endpoints of the intersection line segment, the angle between the two planes corresponding to the intersection line segment, and the contour information Boolean value; Step S30, respectively rotating and translating each plane and each intersection line segment, adjusting each plane and each intersection line segment from an original position to a new position that satisfies a preset condition, and obtaining a Z coordinate value Z0 of each plane at the new position, wherein satisfying the preset condition means that the plane and the intersection line segment are parallel to the XOY plane and the X coordinate value and the Y coordinate value in the three-dimensional coordinates of the point on the plane and the point on the intersection line segment are both greater than 0; Step S40: Based on fractal theory, a rectangular first grid surface is generated in the XOY plane according to a preset accuracy, wherein the first grid surface includes a plurality of grid nodes, and an X coordinate value and a Y coordinate value of each grid node are both greater than 0; Step S50, using the first mesh surface to perform mesh fluctuation attenuation processing on the multiple intersection segments of each plane to obtain multiple second mesh surfaces containing the intersection segments, the number of the second mesh surfaces being the same as the number of the planes, including multiple contour mesh surfaces corresponding to the multiple contour surfaces one-to-one and multiple joint mesh surfaces corresponding to the multiple joint and fracture surfaces one-to-one; Step S60, using the contour intersection line as a cutting line, cutting the plurality of contour mesh surfaces respectively to obtain a plurality of contour fractal surfaces, wherein the plurality of contour fractal surfaces correspond one to one to the plurality of contour surfaces; Step S70, based on the rotation and translation operations, adjusting the plurality of contour fractal surfaces and the plurality of joint mesh surfaces from the new positions back to the original positions, respectively, to obtain a rock mass model to be cut; Step S80: cutting the rock model to be cut based on the internal intersection lines to obtain a plurality of block models.

2. The method for constructing a three-dimensional fracture network rock model according to claim 1, characterized in that: The step of generating a rectangular first grid surface in the XOY plane according to a preset accuracy based on fractal theory includes: Step (a), constructing a rectangular surface in the XOY plane of the three-dimensional coordinate system, wherein the X coordinate value and the Y coordinate value of each point on the rectangular surface are both greater than 0, the area of ​​the rectangular surface is greater than the area of ​​each plane, and the orthographic projection of each plane onto the rectangular surface completely falls within the rectangular surface; Step (b), dividing the rectangular surface into a plurality of rectangular grids of the same size according to the preset accuracy, and obtaining the X coordinate value and the Y coordinate value of each grid node, wherein the preset accuracy includes: a ratio of the length of the rectangular grid to the length of the rectangular surface is 1: (10-100), and a ratio of the width of the rectangular grid to the width of the rectangular surface is 1: (10-100); Step (c), calculating the first fluctuation value of each grid node based on the first formula, obtaining a fluctuation value set and an absolute value of a maximum fluctuation fluctuation value, wherein the fluctuation value set is composed of the first fluctuation values ​​of all grid nodes, and the absolute value of the maximum fluctuation fluctuation value is the value with the largest absolute value among all the first fluctuation values, and the first formula is: ； Wherein, z is the first fluctuation value of the grid node; x is the X coordinate value of the grid node; y is the Y coordinate value of the grid node; L is the sample length; G is the fractal roughness; D is the fractal dimension; γ is the parameter of the frequency distribution; M is the number of superimposed roughness peaks on the rough structure surface; n is the frequency, which is used for iteration during the simulation process; is the upper limit value, used to limit the highest roughness frequency; Ls is the cutoff length; is a random quadrant; Step (d), generating the first mesh surface based on the X coordinate value, Y coordinate value and Z coordinate value of each mesh node, wherein the Z coordinate value of the mesh node is the first fluctuation value of the mesh node.

3. The method for constructing a three-dimensional fracture network rock model according to claim 2, characterized in that: The upper limit value The second formula is used for calculation, and the second formula is: ； Among them, L is the sample length, Ls is the cutoff length, and γ is the parameter of the frequency distribution.

4. The method for constructing a three-dimensional fracture network rock model according to claim 2, characterized in that: The step of using the first mesh surface to perform mesh fluctuation attenuation processing on a plurality of intersection line segments of a plane to obtain a second mesh surface including the intersection line segments comprises: Using the first grid, each intersection line segment of the plane is subjected to grid fluctuation attenuation processing, and a plurality of second fluctuation values ​​after attenuation processing are obtained for each grid node, wherein the plurality of second fluctuation values ​​correspond one-to-one to the plurality of intersection line segments; sorting the plurality of the second fluctuation values ​​of each grid node, and taking the smallest second fluctuation value as the target fluctuation value; Based on the target relief value of each grid node and the Z coordinate value Z0 of the plane, a new Z coordinate value of each grid node is obtained; Based on the X coordinate value, the Y coordinate value and the new Z coordinate value of each mesh node, the position of each mesh node is determined, and a second mesh surface including the intersection line segment is generated.

5. The method for constructing a three-dimensional fracture network rock model according to claim 4, characterized in that: The step of performing grid fluctuation attenuation processing on an intersection line segment of a plane using the first grid surface to obtain a second fluctuation value after attenuation processing comprises: Step (1), based on the intersection line information of the plane intersection line segment and the absolute value of the maximum fluctuation value of the first grid surface, the attenuation range limit value corresponding to the intersection line segment is calculated according to the third formula, and the third formula is: ； in, is the limit value of the attenuation range, z max is the absolute value of the maximum fluctuation value, is the angle between the two planes corresponding to the intersection segment; Step (2), based on the three-dimensional coordinates of each grid node and the intersection line information of the intersection line segment, obtaining the distance d between each grid node and the intersection line segment; Step (3), comparing the distance d between each grid node and the intersection line segment with a preset threshold value, and when the distance d is less than or equal to the preset threshold value, the second fluctuation value after attenuation processing of the grid node is set to 0; Step (4), comparing the distances d between other grid nodes and the intersection line segment that have not been attenuated in step (3) with the attenuation range limit value respectively. When the distances between other grid nodes and the intersection line segment are less than the attenuation range limit value, the second fluctuation value of the grid node is the fluctuation value z obtained by attenuation processing using the fourth formula rd , wherein the fourth formula is: is the limit value of the attenuation range, z max is the absolute value of the maximum fluctuation value, d is the distance between the grid node and the intersection line segment; When the distance between other grid nodes and the intersection line segment is greater than or equal to the attenuation range limit value, the second fluctuation value of the grid node is equal to the first fluctuation value.

6. The method for constructing a three-dimensional fracture network rock model according to claim 1, characterized in that: The step of obtaining the intersection line segment formed by the intersection of any two planes in step S20 includes: Step (1), based on the geometric information of the first plane, obtaining the plane equation of the first plane and the straight line equations corresponding to the first sides of the first plane; Step (2), based on the geometric information of the second plane, obtaining the plane equation of the second plane and the straight line equations corresponding to the plurality of second sides of the second plane; Step (3), solving the plane equation of the first plane and the plane equation of the second plane together to obtain the intersection equation of the first plane and the second plane; Step (4), solving the intersection line equation, the straight line equation of each first side and the straight line equation of each second side respectively, to obtain R intersection point coordinates; Step (5), arranging the coordinates of the R intersection points based on the bubbling order to obtain a sequentially arranged set of intersection points, and connecting them in order to obtain R-1 line segments; Step (6): obtain the midpoints of R-1 line segments respectively, and determine whether the midpoint of each line segment is within the range of both the first plane and the second plane, and take the line segment whose midpoint is within the range of both the first plane and the second plane as the intersection line segment of the first plane and the second plane.

7. The method for constructing a three-dimensional fracture network rock model according to claim 1, characterized in that: The step S10 comprises: Step (1), using drone aerial photography to obtain point cloud data of the rock mass; Step (2), acquiring geometric information of each contour surface of the rock block based on the point cloud data of the rock mass, wherein the geometric information of the contour surface includes vertex coordinates of each vertex constituting the contour surface; Step (3), based on the spatial cluster analysis of the point cloud data and density, identifying the cracks and joint surfaces in different areas of the rock mass contour surface, and extracting the joint data representing the rock mass structure by normal estimation and plane fitting method, wherein the joint data includes joint dip angle and joint inclination; Step (4), constructing each joint fracture surface into a polygonal structure according to the exposure surface information, geological survey information and the joint data, and obtaining geometric information of each joint fracture surface, wherein the geometric information of the joint fracture surface includes the vertex coordinates of each vertex constituting the joint fracture surface.

8. A device for constructing a three-dimensional fracture network rock model, wherein the rock mass comprises a complete rock block and a plurality of joint fracture surfaces located in the rock block, the rock block is a polyhedral structure, and the joint fracture surfaces are polygonal structures, characterized in that: The construction device comprises: A first acquisition module is used to acquire geometric information of a plurality of planes of the rock mass, wherein the geometric information of the planes includes vertex coordinates of each vertex constituting the planes, and the plurality of planes include a plurality of joint fracture surfaces and a plurality of contour surfaces surrounding the contour of the rock block; A second acquisition module is used to acquire, based on geometric information of multiple planes, multiple intersection line segments formed by the intersection of each plane with all other planes, and intersection line information of each intersection line segment, wherein the intersection line segment is divided into a contour intersection line formed by the intersection of two contour surfaces and an internal intersection line formed by the intersection of two contour surfaces, and the intersection line information includes three-dimensional coordinates of two endpoints of the intersection line segment, an angle between two planes corresponding to the intersection line segment, and a contour information Boolean value; A first position adjustment module is used to perform rotation and translation operations on each plane and each intersection line segment respectively, adjust each plane and each intersection line segment from an original position to a new position that meets a preset condition, and obtain a Z coordinate value Z0 of each plane at the new position, wherein satisfying the preset condition means that the plane and the intersection line segment are parallel to the XOY plane and the X coordinate value and the Y coordinate value in the three-dimensional coordinates of the point on the plane and the point on the intersection line segment are both greater than 0; A generating module, for generating a rectangular first mesh surface in an XOY plane according to a preset accuracy based on fractal theory, wherein the first mesh surface includes a plurality of mesh nodes, and an X coordinate value and a Y coordinate value of each mesh node are both greater than 0; A processing module, used for performing grid fluctuation attenuation processing on the multiple intersection line segments of each plane by using the first grid surface to obtain multiple second grid surfaces containing the intersection line segments, wherein the number of the second grid surfaces is the same as the number of the planes, including multiple contour grid surfaces corresponding to the multiple contour surfaces one by one and multiple joint grid surfaces corresponding to the multiple joint fracture surfaces one by one; A cutting module, used for cutting the plurality of contour mesh surfaces respectively by taking the contour intersection line as a cutting line to obtain a plurality of contour fractal surfaces, wherein the plurality of contour fractal surfaces correspond one to one to the plurality of contour surfaces; A second position adjustment module is used to adjust the multiple contour fractal surfaces and the multiple joint grid surfaces from new positions back to original positions based on rotation and translation operations to obtain a rock mass model to be cut; The third acquisition module cuts the rock model to be cut based on the internal intersection line to obtain multiple block models.

9. A computer device, characterized in that: The computer device comprises: a processor and a memory, wherein a computer program is stored in the memory, and when the processor executes the computer program, the computer device implements the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: When the instructions in the computer-readable storage medium are executed by a processor, the processor performs the method according to any one of claims 1 to 7.

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