Columnar joint geometric structure reconstruction method based on Voronoi polygon algorithm

Abstract

The invention discloses a cylindrical joint geometric structure reconstruction method based on a Voronoi polygon algorithm. The cylindrical joint geometric structure reconstruction method comprises the following steps: acquiring geometric characteristic parameters of a cylindrical joint rock mass in a target area; calculating a first parameter and a second parameter according to the obtained geometrical characteristic parameters; determining a corresponding number of initial seed points according to the first parameter; randomly adding an offset value to the initial seed point to obtain a corrected seed point; generating a polygon based on the offset correction seed point and a Voronoi polygon algorithm; calculating a third parameter corresponding to the generated polygon; and determining whether the generated polygon meets the requirement or not according to the relationship between the second parameter and the third parameter. According to the cylindrical joint geometric structure reconstruction method based on the Voronoi polygon algorithm, the generated polygons are judged by adopting the field actual measurement data, and the generation of the polygons is guided, so that the generated polygons are more suitable for the actual situation.

Description

Technical Field

[0001] The invention belongs to the field of rock mechanics and engineering technology, and in particular relates to a columnar joint geometric structure reconstruction method based on a Voronoi polygon algorithm. Background Art

[0002] Columnar joints are widely distributed in igneous rocks, especially in basalt. They are formed by the cutting of blocks by interconnected primary tensile fracture structures to form regular or irregular columnar structures, and the cross-sections are mostly regular hexagons or irregular polygons. Due to the typical geometric characteristics of columnar joint structures, traditional joint fracture statistics methods and corresponding network simulation methods are not very applicable. At present, the Voronoi mathematical method is mainly used to numerically simulate the geometric characteristics of columnar jointed rock mass, and directly generate irregular columnar joint networks. However, when constructing the geometric polygons of columnar joints, existing studies only qualitatively consider the similarity of geometric appearance, lack corresponding quantitative evaluation indicators, and have not yet been unified with field measurement results. Summary of the invention

[0003] The present invention provides a columnar joint geometric structure reconstruction method based on the Voronoi polygon algorithm to solve the above-mentioned technical problems, and specifically adopts the following technical solutions:

[0004] A method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm.

[0005] Obtaining geometric characteristic parameters of columnar jointed rock mass in the target area;

[0006] Calculate the first parameter and the second parameter according to the acquired geometric feature parameters;

[0007] Determine a corresponding number of initial seed points according to the first parameter;

[0008] Randomly adding an offset value to the initial seed point to obtain a correction seed point;

[0009] Generate polygons based on the offset corrected seed points and the Voronoi polygon algorithm;

[0010] Calculate the third parameter corresponding to the generated polygon;

[0011] Determine whether the generated polygon meets the requirements according to the relationship between the second parameter and the third parameter.

[0012] Furthermore, the first parameter is a density parameter of the columnar jointed rock mass in the target area.

[0013] Furthermore, the first parameter is the number N of polygons per unit area of ​​the columnar jointed rock mass in the target area.

[0014] Furthermore, the specific method for determining the corresponding number of seed points according to the first parameter is:

[0015] Based on the obtained number of polygons per unit area N, m seed points are generated in an initially given area with uniform and regular hexagonal grid distribution, where m = N × A, and A is the area of ​​the given area.

[0016] Furthermore, the second parameter is the irregularity coefficient of the columnar jointed rock mass in the target area.

[0017] The third parameter is the irregularity coefficient of the generated polygon.

[0018] Furthermore, the irregularity coefficient χ of the columnar jointed rock mass in the target area and the generated polygons is calculated by the following formula: L ,

[0019]

[0020] Among them, L i is the side length of the cylinder, n is the total number of side lengths, is the average side length of the cylinder, S L is the standard deviation of the cylinder side lengths.

[0021] Furthermore, the specific method for determining whether the generated polygon meets the requirements according to the relationship between the second parameter and the third parameter is:

[0022] Determine whether the difference between the second parameter and the third parameter is within a preset range. If the difference between the second parameter and the third parameter is within the preset range, it indicates whether the generated polygon meets the requirements. If the difference between the second parameter and the third parameter is not within the preset range, randomly add an offset value to the initial seed point again to obtain a new correction seed point, and perform subsequent calculation and judgment steps until the difference between the second parameter and the third parameter is within the preset range.

[0023] Furthermore, the specific method for determining whether the generated polygon meets the requirements according to the relationship between the second parameter and the third parameter is:

[0024] Determine whether the difference between the second parameter and the third parameter is 0. If the difference between the second parameter and the third parameter is 0, it indicates whether the generated polygon meets the requirements. If the difference between the second parameter and the third parameter is not 0, randomly add an offset value to the initial seed point again to obtain a new correction seed point, and perform subsequent calculation and judgment steps until the difference between the second parameter and the third parameter is 0.

[0025] Furthermore, when it is determined that the generated polygon does not meet the requirements, the offset value of the initial seed point is adjusted to obtain a new correction seed point, a new polygon is generated based on the new correction seed point and the Voronoi polygon algorithm, the third parameter corresponding to the generated new polygon is calculated, and it is determined whether the generated new polygon meets the requirements based on the relationship between the second parameter and the third parameter, and the above steps are repeated until the generated polygon meets the requirements.

[0026] Furthermore, when it is determined that the generated polygon meets the requirements, a height parameter is set, and a 3D geometric model is generated based on the generated polygon and the height parameter.

[0027] The benefit of the present invention lies in the provided columnar joint geometric structure reconstruction method based on the Voronoi polygon algorithm, which uses field measured data to judge the generated polygons and guide the generation of polygons, so that the generated polygons are more in line with the actual situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 It is a schematic diagram of the columnar joint geometric structure reconstruction method based on the Voronoi polygon algorithm of the present application;

[0030] Figure 2 It is a schematic diagram of several polygons that are consistent with the field measurement results generated by the Voronoi polygon algorithm of the present application;

[0031] Figure 3 This is a comparison diagram of the distribution of side lengths of several polygons that conform to field measurement results and the target area generated by the Voronoi polygon algorithm of the present application. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0033] like Figure 1 The present invention shows a method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm, which mainly includes:

[0034] S1: Obtain the geometric characteristic parameters of the columnar jointed rock mass in the target area.

[0035] The accurate characterization of joint geometry is of great significance for studying the mechanical behavior of jointed rock mass. As a special case of jointed rock mass, columnar jointed rock mass can be regarded as a prismatic structure formed by cutting several adjacent joint planes, and its cross-sectional polygon is usually an irregular polygon. In order to better study the relevant mechanical properties of columnar jointed rock mass, it is necessary to conduct a comprehensive and detailed study on its geometric structural characteristics.

[0036] Through field testing, the geometric characteristic parameters of the columnar jointed rock mass in the target area are obtained.

[0037] S2: Calculate the first parameter and the second parameter according to the acquired geometric feature parameters.

[0038] The first parameter is a density parameter of the columnar jointed rock mass in the target area. Specifically, in the embodiment of the present application, the first parameter is the number N of polygons per unit area of ​​the columnar jointed rock mass in the target area.

[0039] The second parameter is the irregularity coefficient of the columnar jointed rock mass in the target area.

[0040] In the embodiment of the present application, the irregularity coefficient χ of the columnar jointed rock mass in the target area is calculated by the following formula: L ,

[0041]

[0042] Among them, L i is the side length of the cylinder, n is the total number of side lengths, is the average side length of the cylinder, S L is the standard deviation of the side lengths of the cylinder.

[0043] Based on this, when χ L The larger the value, the higher the degree of columnar irregularity and the more irregular the polygonal shape of the columnar jointed rock cross section. L = 0, indicating that the lengths of the sides of the columns are the same. In this case, the columnar jointed rock mass is a regular hexagonal prism, and its cross-sectional polygon is a regular hexagon. Similarly, based on the area of ​​the column cross-sectional polygon χ A , which can also be used to reflect the irregularity of columnar jointed rock mass.

[0044] After obtaining the geometric structural characteristic parameters of the columnar jointed rock mass in the target area according to the on-site measurement and analysis, the first parameter and the second parameter can be calculated.

[0045] S3: Determine a corresponding number of initial seed points according to the first parameter.

[0046] In the implementation manner of the present application, the specific method for determining the corresponding number of seed points according to the first parameter is:

[0047] Based on the obtained number of polygons per unit area N, m seed points are generated in an initially given area with uniform and regular hexagonal grid distribution, where m = N × A, and A is the area of ​​the given area.

[0048] S4: Randomly add an offset value to the initial seed point to obtain a corrected seed point.

[0049] Specifically, a certain offset value is randomly added to the generated seed point. In the present application, the random offset value is set as follows: the offset value set for the seed point is d / 1000, where d is the distance of the initial seed point. It is understandable that the setting of the initial offset value can be appropriately adjusted according to actual needs.

[0050] S5: Generate polygons based on the offset corrected seed points and the Voronoi polygon algorithm.

[0051] After randomly applying offset values ​​to the seed points, a series of closely spaced polygons are generated based on the offset corrected seed points and the Voronoi polygon algorithm.

[0052] S6: Calculate the third parameter corresponding to the generated polygon.

[0053] In the embodiment of the present application, after the polygon is generated, the third parameter of the generated polygon is calculated. The third parameter is the same as the second parameter, which is the irregularity coefficient of the polygon, and the calculation method is the same as the calculation method of the irregularity coefficient of the columnar jointed rock mass in the target area in step S2.

[0054] S7: Determine whether the generated polygon meets the requirements according to the relationship between the second parameter and the third parameter.

[0055] The specific method to determine whether the generated polygon meets the requirements based on the relationship between the second parameter and the third parameter is:

[0056] Determine whether the difference between the second parameter and the third parameter is within the preset range. If the difference between the second parameter and the third parameter is within the preset range, it means that the generated polygon meets the requirements. If the difference between the second parameter and the third parameter is not within the preset range, the initial seed point is randomly added with an offset value to obtain a new correction seed point, and subsequent calculation and judgment steps are performed until the difference between the second parameter and the third parameter is within the preset range.

[0057] In the implementation manner of the present application, specifically, the specific method for determining whether the generated polygon meets the requirements according to the relationship between the second parameter and the third parameter is:

[0058] Determine whether the difference between the second parameter and the third parameter is 0. If the difference between the second parameter and the third parameter is 0, it means that the generated polygon meets the requirements. If the difference between the second parameter and the third parameter is not 0, the offset value is randomly added to the initial seed point again to obtain a new correction seed point, and subsequent calculation and judgment steps are performed until the difference between the second parameter and the third parameter is 0.

[0059] The process of Voronoi polygons evolving from regular hexagons to irregular polygons is the process of the irregular coefficient gradually increasing, and the irregular coefficient gradually approaches the set third parameter from 0. Each iterative offset is fine-tuned based on the previous offset result. If the required result cannot be generated, the offset value of the seed point is too large, and the offset value of the seed point should be adjusted.

[0060] In an embodiment of the present application, when it is determined that the generated polygon does not meet the requirements, the offset value of the initial seed point is adjusted to obtain a new correction seed point, a new polygon is generated based on the new correction seed point and the Voronoi polygon algorithm, the third parameter corresponding to the generated new polygon is calculated, and it is determined whether the generated new polygon meets the requirements based on the relationship between the second parameter and the third parameter, and the above steps are repeated until the generated polygon meets the requirements.

[0061] This application uses the irregularity of the side length of the polygon as the control condition for the improved Voronoi polygon. A large number of measurement results show that the irregularity coefficient of the side length of the irregular columnar jointed rock mass on site is 0.35. Based on the improved Voronoi polygon algorithm, the Voronoi polygon with an irregularity coefficient of 0.35 is repeatedly generated. Figure 2 A to 2C. Its side length distribution characteristics are as follows Figure 3 As shown in the figure, when the value of the irregularity coefficient is the same as that measured on site, the side length and area distribution of the polygons generated by the improved Voronoi algorithm are basically consistent with the polygons of the columnar jointed rock mass measured on site.

[0062] In an implementation of the present application, when it is determined that the generated polygon meets the requirements, a height parameter is set, and a 3D geometric model is generated based on the generated polygon and the height parameter.

[0063] Specifically, the vertex information of irregular polygons generated based on the improved Voronoi algorithm is stored, and the corresponding three-dimensional node information is compiled according to the column height data, which can then be imported into numerical software such as the finite difference program FLAC3D or the three-dimensional block discrete element program 3DEC to construct the corresponding three-dimensional geometric model.

[0064] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm, characterized in that: Obtaining geometric characteristic parameters of columnar jointed rock mass in the target area; Calculate the first parameter and the second parameter according to the acquired geometric feature parameters; Determine a corresponding number of initial seed points according to the first parameter; Randomly adding an offset value to the initial seed point to obtain a correction seed point; Generate polygons based on the offset corrected seed points and the Voronoi polygon algorithm; Calculate the third parameter corresponding to the generated polygon; Determine whether the generated polygon meets the requirements according to the relationship between the second parameter and the third parameter.

2. The method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm according to claim 1, characterized in that: The first parameter is a density parameter of the columnar jointed rock mass in the target area.

3. The method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm according to claim 2, characterized in that: The first parameter is the number N of polygons per unit area of ​​the columnar jointed rock mass in the target area.

4. The method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm according to claim 3, characterized in that: The specific method for determining the corresponding number of seed points according to the first parameter is: Based on the obtained number of polygons per unit area N, m seed points are generated in an initially given area with uniform and regular hexagonal grid distribution, where m = N × A, and A is the area of ​​the given area.

5. The method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm according to claim 1, characterized in that: The second parameter is the irregularity coefficient of the columnar jointed rock mass in the target area. The third parameter is the irregularity coefficient of the generated polygon.

6. The method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm according to claim 5, characterized in that: The irregularity coefficient χ of the columnar jointed rock mass in the target area and the generated polygons is calculated by the following formula: L , Among them, L i is the side length of the cylinder, n is the total number of side lengths, L is the average side length of the cylinder, S L is the standard deviation of the side lengths of the cylinder.

7. The method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm according to claim 1, characterized in that: The specific method for determining whether the generated polygon meets the requirements according to the relationship between the second parameter and the third parameter is: Determine whether the difference between the second parameter and the third parameter is within a preset range. If the difference between the second parameter and the third parameter is within the preset range, it means that the generated polygon meets the requirements. If the difference between the second parameter and the third parameter is not within the preset range, randomly add an offset value to the initial seed point again to obtain a new correction seed point, and perform subsequent calculation and judgment steps until the difference between the second parameter and the third parameter is within the preset range.

8. The method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm according to claim 1, characterized in that: The specific method for determining whether the generated polygon meets the requirements according to the relationship between the second parameter and the third parameter is: Determine whether the difference between the second parameter and the third parameter is 0. If the difference between the second parameter and the third parameter is 0, it means that the generated polygon meets the requirements. If the difference between the second parameter and the third parameter is not 0, randomly add an offset value to the initial seed point again to obtain a new correction seed point, and perform subsequent calculation and judgment steps until the difference between the second parameter and the third parameter is 0.

9. The method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm according to claim 1, characterized in that: When it is determined that the generated polygon does not meet the requirements, adjust the offset value of the initial seed point to obtain a new correction seed point, generate a new polygon based on the new correction seed point and the Voronoi polygon algorithm, calculate the third parameter corresponding to the generated new polygon, determine whether the generated new polygon meets the requirements based on the relationship between the second parameter and the third parameter, and repeat the above steps until the generated polygon meets the requirements.

10. The method for reconstructing the geometric structure of columnar joints based on the Voronoi polygon algorithm according to claim 1, characterized in that: When it is determined that the generated polygon meets the requirements, a height parameter is set, and a 3D geometric model is generated based on the generated polygon and the height parameter.

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