A multi-faceted domain stratum finite element grid generation method based on a BRep model

Abstract

The application provides a kind of multi-facial domain stratum finite element grid generation method based on BRep model, and relates to the technical field of three-dimensional geological modeling.The main research contents include: processing the drilling data of modeling area, generating open pit mining stope surface based on Delaunay triangulation, and interpolating stratum interface and fault interface etc.combined with distance power inverse ratio method;establishing model range grid according to the required range of modeling;processing between stratum interface and fault interface, and establishing BRep model between stratum interface and fault interface;then, establishing BRep model between model range grid and stratum interface and fault interface, which is the BRep model of multi-facial domain stratum;carrying out irregular tetrahedron partitioning on multi-facial domain stratum space, to realize the generation of finite element grid of multi-facial domain stratum space based on BRep model.The results show that this method can accurately generate finite element grid of multi-facial domain stratum space, and effectively improve work efficiency.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional finite element mesh generation technology, and in particular to a method for generating multi-faceted strata finite element meshes based on the BRep model. Background Technology

[0002] Currently, finite element numerical simulation is widely used in geotechnical engineering, but the quantitative analysis results deviate significantly from reality. Analysis of the reasons for this error is largely related to the accuracy of the finite element mesh. Because modeling complex geological models of multi-domain stratigraphic spaces is extremely difficult, models are often simplified, directly impacting computational accuracy. Simulating arbitrary excavations in actual engineering projects is complex, and modeling complex geological structures such as those containing faults is cumbersome, requiring researchers to possess a high level of expertise, which also severely hinders the further application of finite element analysis in multi-domain stratigraphic spaces. Therefore, finding a simple, efficient, and highly accurate modeling method for multi-domain stratigraphic spaces is an urgent problem to be solved, and it has significant implications for practical applications.

[0003] Currently, several methods for constructing 3D geological models are widely used. 3D models can be broadly categorized into three types based on their set characteristics: volume models, surface models, and line models. Volume models, in particular, can be classified according to their representation methods: boundary representation (BRep), structural representation (CSG), and decomposition representation. However, for complex 3D geological solid models involving multi-faceted stratigraphic spaces, there are still some problems such as insufficient accuracy, low efficiency, and limited adaptability. These problems restrict the application of finite element numerical simulation in the geotechnical field. Therefore, finite element mesh generation methods for multi-faceted stratigraphic spaces are crucial.

[0004] Inventive Method

[0005] In response to the emergence of new technologies and the shortcomings of existing technologies, this invention provides a method for generating multi-faceted strata finite element meshes based on the BRep model.

[0006] A method for generating multi-faceted finite element meshes for geological formations based on the BRep model includes the following steps:

[0007] Step 1: Establish a triangular mesh for the open-pit mine, stratigraphic interfaces, and fault interfaces. The specific method is as follows:

[0008] Constrained Delaunay triangulation is applied to the bench lines of the open-pit mine to generate open-pit mine scenes. Using borehole lithology distribution data as samples, the inverse square distance method is used to interpolate the required lithology data, generating triangular meshes for each stratigraphic interface and fault interface. The resulting triangle set T = {t1, t2, ..., t} of the open-pit mine scenes is obtained. i ,...,t n}, where ti Let be the i-th triangle in the open-pit mine, i∈[1,n], where n is the total number of triangles in the open-pit mine; thus, obtain the triangle set L={l 11 ,l 12 ,...,l re ,...,l oq}, where l re Let be the e-th triangle on the r-th stratigraphic interface, and q be the total number of triangles on the o-th stratigraphic interface; thus, the triangle set F = {f} of the fault interface is obtained. 11 ,f 12 ,...,f hg ,...,f vb}, where f hg Let b be the g-th triangle on the h-th fault interface, and b be the total number of triangles on the v-th fault interface.

[0009] Step 2: Establish a model-wide mesh with the mining area as the surface. The specific method is as follows:

[0010] Step 2.1: Create a quadrilateral mesh for the model area according to the given length, width, and height dimensions;

[0011] Furthermore, we obtain the quadrilateral set M = {m1, m2, ..., m}. x ,...,m z}, where m x Let x be the x-th quadrilateral on the quadrilateral grid of the model range, x∈[1,z], and z be the total number of quadrilaterals in the model range.

[0012] Step 2.2: Constrain the model range mesh at the stope interface to form a model range mesh set M′ with the stope as the surface. The specific method is as follows:

[0013] Step 2.2.1: Find the intersection between the open-pit mine interface and the model range mesh to obtain the intersection line P = {p1, p2, ..., p y ,...,p u}, as constraint edges, where p y Let y be the y-th point on the constraint line, where y∈[1,u] and u is the total number of points on the constraint line;

[0014] Step 2.2.2: Add the constraint edge P to the stope interface triangle set T and the model range mesh set M according to the Delaunay criterion. Use the constraint edge as the boundary to delete redundant stope interface triangles and model range mesh quadrilaterals, retain the valid stope triangles and model range quadrilaterals, and combine them to form the model range mesh set M′ with the stope as the surface.

[0015] Step 3: Establish mutual constraints between the stratigraphic interface and the fault interface. The specific method is as follows:

[0016] Step 3.1: Constrain the stratigraphic interface to obtain an effective set of stratigraphic triangles L';

[0017] Furthermore, the intersection of two mutually constrained stratigraphic interface triangular meshes L and fault interface triangular mesh F is obtained to obtain the intersection line between the stratigraphic interface and the fault interface. This intersection line is used as the constraint edge P of the stratigraphic interface. The constraint edge P is added to the stratigraphic interface triangle set L according to the Delaunay criterion. Then, redundant triangles of the stratigraphic interface are deleted with the constraint edge P as the boundary, and the effective set of bedding plane triangles L' is retained.

[0018] Step 3.2: Add the constraint edge P to the triangular mesh F of the fault interface according to the Delaunay criterion to form the fault plane F';

[0019] Furthermore, the topological relationships between strata are determined according to the formation mechanism of each stratum. The above method is repeated according to the sequence of strata interfaces until the intersection between all strata interfaces and fault interfaces is completed and the triangular mesh of the fault interfaces is constrained, thus realizing the constraint between strata interfaces and fault interfaces.

[0020] Step 4: Establish a multi-faceted stratigraphic spatial BRep model. The specific method is as follows:

[0021] Step 4.1: Use the range mesh M' constructed from the open-pit mine surface to establish a multi-region BRep model of the stratigraphic interface L'. The specific establishment method is as follows:

[0022] Step 4.1.1: Based on the establishment of two mutually constrained stratigraphic interfaces L' and model range mesh M', obtain the intersection line between the stratigraphic interface and the model range mesh. Use this intersection line as the constraint line P of the stratigraphic interface and add it to the stratigraphic interface triangular mesh according to the Delaunay criterion. Delete the redundant triangular mesh of the stratigraphic interface with the constraint line P as the boundary, and retain the effective layer L”.

[0023] Step 4.1.2: Use the formation interface L' to constrain the outer mesh M', combine the constrained outer meshes to form the outer mesh M″. Repeat the above operation according to the formation interface sequence until all formation interfaces and the range meshes are constrained, thus realizing the constraint between the formation interface and the range meshes.

[0024] Step 4.2: Use the outer mesh M” constructed from the open-pit mine surface to establish a multi-region BRep model of the fault interface F'. The specific establishment method is as follows:

[0025] Step 4.2.1: Find the intersection line between the fault interface F' and the outer mesh M”. Use this intersection line as the constraint line P of the fault interface and add it to the triangular mesh of the fault interface according to the Delaunay criterion. Delete the redundant triangular mesh of the fault interface with the constraint line P as the boundary, and retain the effective fault plane F”.

[0026] Step 4.2.2: Use the fault interface F' to constrain the outer mesh M”, combine the constrained outer meshes to form the outer mesh M”′. Repeat the above operation in sequence until the constraint operation between all fault interfaces and outer meshes is completed, thus completing the establishment of the multi-faceted stratigraphic space BRep model.

[0027] Step 5: Tetrahedral subdivision of the multi-region stratigraphic space BRep model to generate finite element mesh;

[0028] Furthermore, the established multi-faceted stratigraphic space BRep model is subjected to Delaunay irregular tetrahedral subdivision to realize the generation of multi-faceted stratigraphic space finite element mesh based on the BRep model.

[0029] As can be seen from the above technical solution, the beneficial effects of the present invention are as follows: The present invention provides a multi-domain stratigraphic finite element mesh generation method based on the BRep model, which efficiently generates finite element meshes for multi-domain stratigraphic space in order to effectively perform numerical simulations. By constraining the mining interface, stratigraphic interface, and fault interface through the outer mesh, a BRep model between the stratigraphic interface and the fault interface is established. Further, a multi-domain stratigraphic space BRep model is established, and then its tetrahedral subdivision is used to generate a finite element mesh. This overcomes the shortcomings of existing finite element mesh generation methods for complex geological models, fully utilizes the advantages of boundary representation, and efficiently establishes a three-dimensional model of multi-domain stratigraphic space, thereby improving work efficiency. Attached Figure Description

[0030] Figure 1 A flowchart illustrating a method for generating multi-faceted strata finite element meshes based on the BRep model, provided in an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of an open-pit mine, stratigraphic interface, and fault interface provided for an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the outer grid triangle of a triangular cut in an open-pit mine, provided in an embodiment of the present invention.

[0033] Figure 4 A schematic diagram of the BRep model between the open-pit mine strata interface and the fault interface provided in an embodiment of the present invention;

[0034] Figure 5This is a schematic diagram of the BRep model of multi-faceted stratigraphic space in an open-pit mine provided in an embodiment of the present invention;

[0035] Figure 6 A schematic diagram of the finite element mesh of the BRep model of multi-faceted stratigraphic space in an open-pit mine provided in an embodiment of the present invention.

[0036] Figure 7 This is a schematic diagram of the internal structure of the finite element mesh of the BRep model of the multi-faceted strata space in an open-pit mine, provided in an embodiment of the present invention. Detailed Implementation

[0037] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0038] This embodiment uses lithological distribution data of an open-pit coal mine in Xilinhot as a basis to establish a three-dimensional model of the area, which is implemented by a multi-faceted stratum finite element mesh generation method based on the BRep model.

[0039] A method for generating multi-faceted strata finite element meshes based on the BRep model, such as Figure 1 As shown, it includes the following steps:

[0040] Step 1: Establish a triangular mesh for the open-pit mine, stratigraphic interfaces, and fault interfaces. The specific method is as follows:

[0041] Constrained Delaunay triangulation is applied to the bench lines of the open-pit mine to generate open-pit mine scenes. Using borehole lithology distribution data as samples, the inverse square distance method is used to interpolate the required lithology data, generating triangular meshes for each stratigraphic interface and fault interface. The resulting triangle set T = {t1, t2, ..., t} of the open-pit mine scenes is obtained. i ,...,t n}, where t i Let be the i-th triangle in the open-pit mine, i∈[1,n], where n is the total number of triangles in the open-pit mine; thus, obtain the triangle set L={l 11 ,l 12 ,...,l re ,...,l oq}, where l re Let be the e-th triangle on the r-th stratigraphic interface, and q be the total number of triangles on the o-th stratigraphic interface; thus, the triangle set F = {f} of the fault interface is obtained. 11 ,f 12 ,...,f hg ,...,f vb}, where f hgLet b be the g-th triangle on the h-th fault interface, and b be the total number of triangles on the v-th fault interface.

[0042] This embodiment contains 176 valid boreholes. When extracting borehole data from the data file into the borehole database, the longitude and latitude coordinates of the boreholes need to be converted into x and y coordinates. Triangular meshes of various strata and fault planes are generated using the inverse power law interpolation method. Then, grouped layers are created, and different layer colors are assigned to different strata, such as... Figure 2 As shown. From top to bottom, the following are imported: the surface of the open-pit mine, the Quaternary strata, the Tertiary strata, the top of coal seam 6, the bottom of coal seam 6, and fault planes FGe1 and FGe2. Both faults are normal faults. The displacement of FGe1 is 30m, and that of FGe2 is 35m. FGe2 was formed later than FGe1. The triangle set on the mine surface contains 9419 triangles, the Quaternary triangle set contains 2654 triangles, the Tertiary triangle set contains 2654 triangles, the top of coal seam 6 contains 2654 triangles, the bottom of coal seam 6 contains 2634 triangles, and fault planes FGe1 and FGe2 contain 833 and 1184 triangles respectively.

[0043] Step 2: Establish a model-wide mesh with the mining area as the surface. The specific method is as follows:

[0044] Step 2.1: Create a quadrilateral mesh for the model area according to the given length, width, and height dimensions;

[0045] Furthermore, we obtain the quadrilateral set M = {m1, m2, ..., m}. x ,...,m z}, where m x Let x be the x-th quadrilateral on the quadrilateral grid of the model range, x∈[1,z], and z be the total number of quadrilaterals in the model range.

[0046] Step 2.2: Constrain the model range mesh at the stope interface to form a model range mesh set M′ with the stope as the surface. The specific method is as follows:

[0047] Step 2.2.1: Find the intersection between the open-pit mine interface and the model range mesh to obtain the intersection line P = {p1, p2, ..., p y ,...,p u}, as constraint edges, where p y Let y be the y-th point on the constraint line, where y∈[1,u] and u is the total number of points on the constraint line;

[0048] Step 2.2.2: Add the constraint edge P to the stope interface triangle set T and the model range mesh set M according to the Delaunay criterion. Use the constraint edge as the boundary to delete redundant stope interface triangles and model range mesh quadrilaterals, retain the valid stope triangles and model range quadrilaterals, and combine them to form the model range mesh set M′ with the stope as the surface.

[0049] This embodiment establishes a model range mesh based on a cuboid-shaped area with a length of 1700m, a width of 1600m, and a height of 500m. The quadrilateral set contains 600 quadrilaterals. Then, the intersection line P between the open-pit mine interface and the model range mesh M is obtained. The constraint line P contains 654 points. Calculations are performed using Delaunay triangulation based on constraint edges. The constraint lines are copied to the mine interface and the model range mesh. Redundant mine interface triangles and model range mesh quadrilaterals are deleted using the constraint lines as boundaries, retaining only valid mine triangles and model range quadrilaterals. These are then combined to form a model range mesh set M′ with the mine as the surface. This set contains 9253 quadrilaterals and 1095 quadrilaterals. Figure 3 As shown.

[0050] Step 3: Establish mutual constraints between the stratigraphic interface and the fault interface. The specific method is as follows:

[0051] Step 3.1: Constrain the stratigraphic interface to obtain an effective set of stratigraphic triangles L';

[0052] Furthermore, the intersection of two mutually constrained stratigraphic interface triangular meshes L and fault interface triangular mesh F is obtained to obtain the intersection line between the stratigraphic interface and the fault interface. This intersection line is used as the constraint edge P of the stratigraphic interface. The constraint edge P is added to the stratigraphic interface triangle set L according to the Delaunay criterion. Then, redundant triangles of the stratigraphic interface are deleted with the constraint edge P as the boundary, and the effective set of bedding plane triangles L' is retained.

[0053] Step 3.2: Add the constraint edge P to the triangular mesh F of the fault interface according to the Delaunay criterion to form the fault plane F';

[0054] Furthermore, the topological relationships between strata are determined according to the formation mechanism of each stratum. The above method is repeated according to the sequence of strata interfaces until the intersection between all strata interfaces and fault interfaces is completed and the triangular mesh of the fault interfaces is constrained, thus realizing the constraint between strata interfaces and fault interfaces.

[0055] This embodiment, based on the displacement of faults FGe1 and FGe2, performs corresponding displacement analysis on the top and bottom of the 6-coal seam. Specifically, for faults FGe1 and FGe2, only the top and bottom of the 6-coal seam are constrained for intersection. First, the intersection operation with the fault plane FGe1 is performed in the order of the top and bottom of the 6-coal seam. Redundant triangular meshes at the stratigraphic interface are deleted using the constraint line P as the boundary, retaining the valid top and bottom of the 6-coal seam. Then, the fault plane FGe1 is constrained and segmented using Quaternary, Tertiary, top, and bottom of the 6-coal seam, and the segmented fault plane FGe1 is merged to realize the BRep model between the stratigraphic plane and fault FGe1. Then, following the above steps, the BRep model between the stratigraphic plane and fault FGe2 is established, thus realizing the constraint model between the stratigraphic interface and faults FGe1 and FGe2. Figure 4 As shown.

[0056] Step 4: Establish a multi-faceted stratigraphic spatial BRep model. The specific method is as follows:

[0057] Step 4.1: Use the range mesh M' constructed from the open-pit mine surface to establish a multi-region BRep model of the stratigraphic interface L'. The specific establishment method is as follows:

[0058] Step 4.1.1: Based on the establishment of two mutually constrained stratigraphic interfaces L' and model range mesh M', obtain the intersection line between the stratigraphic interface and the model range mesh. Use this intersection line as the constraint line P of the stratigraphic interface and add it to the stratigraphic interface triangular mesh according to the Delaunay criterion. Delete the redundant triangular mesh of the stratigraphic interface with the constraint line P as the boundary, and retain the effective layer L”.

[0059] Step 4.1.2: Use the formation interface L' to constrain the outer mesh M', combine the constrained outer meshes to form the outer mesh M'′. Repeat the above operation according to the formation interface sequence until all formation interfaces and the range meshes are constrained, thus realizing the constraint between the formation interface and the range meshes.

[0060] Step 4.2: Use the outer mesh M” constructed from the open-pit mine surface to establish a multi-region BRep model of the fault interface F'. The specific establishment method is as follows:

[0061] Step 4.2.1: Find the intersection line between the fault interface F' and the outer mesh M”. Use this intersection line as the constraint line P of the fault interface and add it to the triangular mesh of the fault interface according to the Delaunay criterion. Delete the redundant triangular mesh of the fault interface with the constraint line P as the boundary, and retain the effective fault plane F”.

[0062] Step 4.2.2: Use the fault interface F' to constrain the outer mesh M”, combine the constrained outer meshes to form the outer mesh M”′. Repeat the above operation in sequence until the constraint operation between all fault interfaces and outer meshes is completed, thus completing the establishment of the multi-faceted stratigraphic space BRep model.

[0063] This embodiment uses the model range grid and the Quaternary, Tertiary, 6-coal seam top, 6-coal seam bottom, and two fault planes, FGe1 and FGe2, to establish a multi-region stratigraphic spatial BRep model. First, a BRep model is established between the Quaternary, Tertiary, 6-coal seam top, 6-coal seam bottom, and the model range grid. Based on the intersection line between the Quaternary and the model range grid, this intersection line is used as the constraint line for the Quaternary. Redundant triangular meshes at the Quaternary interface are deleted using the constraint line as the boundary, retaining the effective planes. Then, the Quaternary is used to perform constraint segmentation on the outer mesh. The constrained outer meshes are combined to form the outer mesh. The above operation is repeated for the Tertiary, 6-coal seam top, and 6-coal seam bottom until the intersection segmentation operation between all stratigraphic interfaces and the range grid is completed, thus realizing the constraint between the stratigraphic interfaces and the range grid. Following the same procedure described above for establishing constraints between stratigraphic interfaces and the boundary grid, BRep models are then sequentially established between the two fault planes, FGe1 and FGe2, and the model boundary grid. This completes the construction of the multi-faceted stratigraphic space BRep model for the open-pit mine. Figure 5 As shown.

[0064] Step 5: Tetrahedral subdivision of the multi-region stratigraphic space BRep model to generate finite element mesh;

[0065] Furthermore, the established multi-faceted stratigraphic space BRep model is subjected to Delaunay irregular tetrahedral subdivision to realize the generation of multi-faceted stratigraphic space finite element mesh based on the BRep model.

[0066] This embodiment performs irregular tetrahedral subdivision on the established BRep model of multi-region stratigraphic space in open-pit mines, realizing the generation of finite element meshes for multi-region stratigraphic space based on the BRep model. The generated finite element mesh contains 270,008 tetrahedra, divided into 5 types of geological bodies with different geological characteristics, such as... Figure 6 As shown, the internal structure of the finite element mesh is as follows Figure 7 As shown.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of the present invention.

Claims

1. A multi-facies domain stratum finite element mesh generation method based on a BRep model, characterized in that, Includes the following steps: Step 1: Establish a triangular mesh for the open-pit mine, stratigraphic interfaces, and fault interfaces; Step 2: Establish a model-wide mesh with the mining area as the surface. The specific method is as follows: Step 2.1: Create a quadrilateral mesh for the model area according to the given length, width, and height dimensions; Step 2.2: Constrain the model range mesh at the stope interface to form a model range mesh set Mʹ with the stope as the surface; Step 3: Establish mutual constraints between the stratigraphic interface and the fault interface. The specific method is as follows: Step 3.1: Constrain the stratigraphic interface to obtain an effective set of stratigraphic triangles L'; Step 3.2: Add the constraint edge P to the triangular mesh F of the fault interface according to the Delaunay criterion to form the fault plane F'; Step 4: Establish a multi-faceted stratigraphic spatial BRep model; Step 5: Tetrahedral subdivision of the multi-region stratigraphic space BRep model to generate finite element mesh; The specific method for step 4 is as follows: Step 4.1: Use the range mesh M' constructed from the open-pit mine surface to establish a multi-region BRep model of the stratigraphic interface L'. The specific establishment method is as follows: Step 4.1.1: Based on the establishment of two mutually constrained stratigraphic interfaces L' and the model range mesh Mʹ, obtain the intersection line between the stratigraphic interface and the model range mesh. Use this intersection line as the constraint line P of the stratigraphic interface and add it to the stratigraphic interface triangular mesh according to the Delaunay criterion. Delete the redundant triangular mesh of the stratigraphic interface with the constraint line P as the boundary, and retain the effective layer L''. Step 4.1.2: Use the formation interface L' to constrain the outer mesh M', combine the constrained outer meshes to form the outer mesh M'ʹ. Repeat the above operation according to the formation interface sequence until all formation interfaces and the range meshes are constrained, thus realizing the constraint between the formation interface and the range meshes. Step 4.2: Use the outer mesh M'' constructed from the open-pit mine surface to establish a multi-region BRep model of the fault interface F'. The specific establishment method is as follows: Step 4.2.1: Find the intersection line between the fault interface F' and the outer mesh M''. Add this intersection line as the constraint line P of the fault interface to the triangular mesh of the fault interface according to the Delaunay criterion. Delete the redundant triangular mesh of the fault interface with the constraint line P as the boundary, and retain the effective fault plane F''. Step 4.2.2: Use the fault interface F' to constrain the outer mesh M'', combine the constrained outer meshes to form the outer mesh M''ʹ. Repeat the above operation in sequence until all fault interfaces and outer meshes are constrained, thus completing the establishment of the multi-faceted stratigraphic space BRep model.

2. The method of claim 1, wherein, The specific method for step 1 is as follows: Constrained Delaunay triangulation is applied to the bench lines of the open-pit mine to generate open-pit mine scene data. Using borehole lithology distribution data as samples, the inverse square distance method is used to interpolate the required lithology data, generating triangular meshes for each stratigraphic interface and fault interface. The resulting triangle set of the open-pit mine scene is then obtained. ,in, Let i be the i-th triangle in the open-pit mine. Let n be the total number of triangles in the open-pit mine; obtain the triangle set of the stratigraphic interface. ,in, Let be the e-th triangle on the r-th stratigraphic interface, and q be the total number of triangles on the o-th stratigraphic interface; thus, obtain the triangle set of the fault interface. ,in, Let b be the g-th triangle on the h-th fault interface, and b be the total number of triangles on the v-th fault interface.

3. The method of claim 1, wherein, The specific method for step 2 is as follows: Step 2.1: Create a quadrilateral mesh for the model area according to the given length, width, and height dimensions; Furthermore, we obtain the quadrilateral set. ,in, For the x-th quadrilateral on the quadrilateral grid within the model range, z is the total number of quadrilaterals within the model range; Step 2.2: Constrain the model range mesh at the stope interface to form a model range mesh set Mʹ with the stope as the surface. The specific method is as follows: Step 2.2.1: Intersect the pit-slice interface with the model extent grid to get intersection lines , as a constraint edge, where, is the ythpoint on the constraint line, , u is the total number of points on the constraint line; Step 2.2.2: Add the constraint edge P to the stope interface triangle set T and the model range mesh set M according to the Delaunay criterion. Use the constraint edge as the boundary to delete redundant stope interface triangles and model range mesh quadrilaterals, retain the valid stope triangles and model range quadrilaterals, and combine them to form the model range mesh set Mʹ with the stope as the surface.

4. The method of claim 1, wherein, The specific method for step 3 is as follows: Step 3.1: Constrain the stratigraphic interface to obtain an effective set of stratigraphic triangles L'; Furthermore, the intersection of two mutually constrained stratigraphic interface triangular meshes L and fault interface triangular mesh F is obtained to obtain the intersection line between the stratigraphic interface and the fault interface. This intersection line is used as the constraint edge P of the stratigraphic interface. The constraint edge P is added to the stratigraphic interface triangle set L according to the Delaunay criterion. The redundant triangles of the stratigraphic interface are deleted with the constraint edge P as the boundary, and the effective set of bedding triangles L' is retained. Step 3.2: Add the constraint edge P to the triangular mesh F of the fault interface according to the Delaunay criterion to form the fault plane F'; Furthermore, the topological relationships between strata are determined according to the formation mechanism of each stratum. The above method is repeated according to the sequence of strata interfaces until the intersection between all strata interfaces and fault interfaces is completed and the triangular mesh of the fault interfaces is constrained, thus realizing the constraint between strata interfaces and fault interfaces.

5. The method of claim 1, wherein, The specific method for step 5 is as follows: Furthermore, the established multi-faceted stratigraphic space BRep model is subjected to Delaunay irregular tetrahedral subdivision to realize the generation of multi-faceted stratigraphic space finite element mesh based on the BRep model.

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