A geological structure modeling method for tunnel geological structure refinement and three-dimensional ground stress field dynamic inversion

Abstract

The present application relates to a kind of geological structure modeling method for tunnel geological structure refinement and three-dimensional ground stress field dynamic inversion, can refine complex geological structure, to improve the inversion accuracy of initial ground stress field in tunnel area. Specifically include determining the modeling range of geological structure model;In the modeling range, generate topographic three-dimensional model;In topographic three-dimensional model, it is divided into tunnel along line geological structure modeling area and tunnel area geological structure modeling area;According to tunnel along line geological structure modeling area, generate first three-dimensional geological model;According to tunnel area geological structure modeling area, generate second three-dimensional geological model. Wherein, first three-dimensional geological model is in tunnel along line geological structure modeling area generation geological structure feature;Second three-dimensional geological model is in tunnel area geological structure modeling area generation geological structure feature.

Description

Technical Field

[0001] This invention relates to the field of solid modeling technology, and in particular to a geological structure modeling method for refining tunnel geological structures and dynamically inverting three-dimensional geostress fields. Background Technology

[0002] Geological structures refer to the shapes left behind by the deformation or displacement of rock strata or rock masses under the action of internal and external stresses on Earth. Because tunnel construction is often constrained by environmental factors, conducting in-situ stress measurements is difficult, leading to the development of three-dimensional geological structure models.

[0003] A three-dimensional geological structure model is a three-dimensional visualization model. Unlike a two-dimensional model built based on the longitudinal profile of the tunnel axis, which can only represent height changes in two directions, a three-dimensional geological structure model can reflect height changes in three directions: X, Y, and Z. However, it cannot reflect the strike, dip angle, and complex changes in lithology at depth with elevation of complex geological structures, thus reducing the accuracy of the initial geostress field inversion in the tunnel engineering area. Summary of the Invention

[0004] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a geological structure modeling method for refining the geological structure of tunnels and dynamically inverting the three-dimensional geostress field. The above method can refine complex geological structures, thereby improving the inversion accuracy of the initial geostress field of the tunnel engineering area.

[0005] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0006] In a first aspect, embodiments of the present invention provide a geological structure modeling method for refining tunnel geological structures and dynamically inverting three-dimensional geostress fields, characterized by comprising: S1: determining the modeling range of the geological structure model; S2: generating a three-dimensional terrain model within the modeling range; S3: dividing the three-dimensional terrain model into a geological structure modeling area along the tunnel and a geological structure modeling area at the tunnel site; S4: generating a first three-dimensional geological model based on the geological structure modeling area along the tunnel; and generating a second three-dimensional geological model based on the geological structure modeling area at the tunnel site. The first three-dimensional geological model generates geological structure features within the geological structure modeling area along the tunnel; the second three-dimensional geological model generates geological structure features within the geological structure modeling area at the tunnel site.

[0007] After determining the modeling scope, a basic 3D terrain model is first generated. Based on the different geological structures along the tunnel and the tunnel site area, the geological structures are refined to generate their respective geological structures. Finally, the first and second 3D geological models are obtained, which can accurately reflect the influence of high ground stress and improve the accuracy of the inversion.

[0008] As one possible implementation method, determining the modeling scope of the geological structure model includes: S11: Determining the modeling scope of the first geological structure model and screening key geological information based on the tunnel plan construction drawings, tunnel axis profile drawings, and engineering geological survey reports. Key geological information includes: faults, dense joint zones, contour lines, and the mileage and orientation of the tunnel within the modeling scope of the geological structure model. S12: Expanding the modeling scope of the first geological structure model based on the tunnel length and orientation to obtain the modeling scope of the second geological structure model. The modeling scope of the second geological structure model is the determined modeling scope of the geological structure model.

[0009] By appropriately expanding the modeling scope, the modeling tolerance can be improved, and the impact of boundary effects can be reduced. Key geological information, such as faults, densely jointed zones, contour lines, and the mileage and orientation along the tunnel, can be filtered out to facilitate rapid data retrieval during modeling.

[0010] As one possible implementation, generating a 3D terrain model within the modeling scope includes: S21: generating spatial point cloud data of the 3D terrain model based on contour lines; S22: generating a terrain mesh by meshing the spatial point cloud data of the 3D terrain model; S23: smoothing the terrain mesh and generating the 3D terrain model.

[0011] As one possible implementation, the terrain 3D model is divided into a geological structure modeling area along the tunnel and a geological structure modeling area at the tunnel site, including: S31: The geological structure modeling area along the tunnel is determined according to the radial direction and axial length of the tunnel, and the remaining area is the geological structure modeling area at the tunnel site.

[0012] As one possible approach, geological structural features include faults, densely jointed zones, and lithological boundaries.

[0013] As one possible implementation, generating a first three-dimensional geological model based on the geological structure modeling area along the tunnel; generating a second three-dimensional geological model based on the geological structure modeling area of ​​the tunnel site includes: S41: Determining the thickness and modeling location of faults and densely jointed zones within the geological structure modeling area of ​​the tunnel site based on the tunnel axis profile and the engineering geological survey report. S42: Performing three-dimensional solidification of faults and densely jointed zones and Boolean operations to generate the second three-dimensional geological model. S43: Determining the thickness, strike, dip angle, and lithological boundary location of faults and densely jointed zones within the geological structure modeling area along the tunnel based on the tunnel axis profile and the engineering geological survey report. S44: Performing three-dimensional solidification of faults and densely jointed zones based on dip angle and strike and Boolean operations; performing Boolean operations on lithological boundaries to generate the first three-dimensional geological model.

[0014] By dividing the geological structure modeling area along the tunnel and the geological structure modeling area at the tunnel site, more targeted and refined modeling is achieved. Based on the different effects of high ground stress caused by different geological structures in the two different areas, different faults, dense joint zones, and lithological boundaries are generated, making the modeling more accurate.

[0015] As one possible implementation, after generating a first three-dimensional geological model based on the geological structure modeling area along the tunnel and a second three-dimensional geological model based on the geological structure modeling area of ​​the tunnel site, the method further includes: performing mesh refinement processing on the geological structure features. Mesh refinement processing ensures the accuracy of modeling and provides a reliable model for in-situ stress inversion.

[0016] As one possible approach, the first and second three-dimensional geological models, after undergoing mesh refinement processing of geological structural features, have the same mesh size for fault and joint dense zones, while the mesh size for other terrain features is the same.

[0017] As one possible approach, after refining the grid of geological structural features, the method also includes an accuracy assessment of comparing the inverted in-situ stress values ​​with the measured borehole values; the accuracy assessment is based on the formula: δ=(X 实测 -X 反演 ) / X 实测 If the accuracy δ is greater than or equal to 85%, it indicates that the modeling is reasonable and the inversion is correct. Attached Figure Description

[0018] Figure 1 A schematic diagram of a geological structure modeling method for dynamic inversion of three-dimensional geostress field and refined tunnel structure provided in this application embodiment;

[0019] Figure 2 A schematic diagram of the modeling range of the geological structure model provided in the embodiments of this application;

[0020] Figure 3 A schematic diagram of another geological structure modeling method for dynamic inversion of three-dimensional geostress field and refined tunnel structure provided in this application embodiment;

[0021] Figure 4 A schematic diagram of the modeling range for another geological structure model provided in this application embodiment;

[0022] Figure 5 This is a schematic diagram illustrating the steps of generating a 3D terrain model within the modeling range, as provided in an embodiment of this application.

[0023] Figure 6 A schematic diagram of the terrain surface provided in the embodiments of this application;

[0024] Figure 7This is a schematic diagram of the three-dimensional topographic surface provided in the embodiments of this application;

[0025] Figure 8 A schematic diagram of the geological structure modeling area along the tunnel and the geological structure modeling area at the tunnel site, provided in the embodiments of this application;

[0026] Figure 9 This is a schematic diagram of the refined modeling of the geological structure modeling area along the tunnel provided in the embodiments of this application;

[0027] Figure 10 A schematic diagram of the refined model provided in the embodiments of this application. Detailed Implementation

[0028] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] The geological structure modeling method proposed in this application for refining tunnel geological structures and dynamically inverting three-dimensional geostress fields can effectively improve the geological structure characteristics of tunnel sites that cannot be refined by three-dimensional geological structure models, thereby improving the accuracy of model inversion.

[0030] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0031] A tunnel is a passageway excavated within an existing building or earth-rock structure; it is an engineering structure buried underground. As an underground passageway, tunnels offer unparalleled advantages over other engineering projects. For example, in mountainous areas, they can overcome terrain or elevation obstacles, improve alignment, shorten distances, save time, and reduce damage to vegetation; in rivers, straits, and harbors, they do not affect navigation, improve comfort, increase concealment, and are unaffected by weather. Therefore, tunnel construction plays a positive role in promoting transportation development.

[0032] Tunnel construction involves not only geological and topographical exploration of the tunnel itself, but also a detailed investigation of the surrounding geological area, i.e., the tunnel site area. This is because there are many faults and densely jointed zones present during complex geological processes.

[0033] A fault is a geological structure in which the Earth's crust fractures under stress, resulting in significant relative displacement of rock blocks on either side of the fracture surface. A densely jointed zone is a small-scale fracture geological structure where the rock blocks on either side of the fracture do not experience significant displacement. Both faults and densely jointed zones reduce the strength and stability of the rock mass and can also affect the integrity of the rock mass and the anti-slip resistance of the tunnel surface, thus impacting the overall construction safety of the tunnel.

[0034] In addition, high ground stress can also affect tunnel construction. High ground stress is defined as the stress level within a rock mass divided by the strength of the surrounding rock exceeding a certain value; this is typically tested using deep-hole drilling in tunnel construction. For hard and brittle rock masses, high ground stress can cause rock bursts, while for soft rock, it can cause severe deformation.

[0035] In actual exploration, the measurement of high ground stress is greatly limited due to environmental and climatic factors. The limited number of measuring points leads to the dispersion of ground stress measurements, which cannot reflect the overall ground stress field of the region. Therefore, there is a need to establish a refined model and accurately invert ground stress.

[0036] See Figure 1 , Figure 1 This application illustrates a geological structure modeling method for refining tunnel geological structures and dynamically inverting three-dimensional geostress fields, comprising the following steps:

[0037] S1: Determine the modeling scope of the geological structure model;

[0038] The modeling scope of the geological structure model is determined based on the anticipated tunnel construction plan. This scope includes the tunnel site area and the tunnel itself. A key aspect of selecting the modeling scope is ensuring that both the tunnel's starting and ending points are included within the defined area. Specifically, as follows... Figure 2 As shown, Figure 2 The modeling scope of the geological structure model provided in this embodiment is shown. The dashed box represents the modeling scope of the geological structure model, which includes the tunnel with its starting and ending points and the surrounding tunnel site area. The length and width of the modeling scope are determined by a diagonal line drawn from the starting and ending points of the tunnel.

[0039] S2: Generate a 3D terrain model within the modeling scope;

[0040] Based on the tunnel construction plan, tunnel profile, and engineering geological survey report, a 3D terrain model is generated within the defined modeling area. A 2D model can only reflect simple terrain changes. In contrast, a 3D model, which can only represent geological structural information from a single profile, offers a broader perspective on geological structures such as faults and densely jointed zones. Therefore, it can reflect more complex geological structures, including their orientation and dip angle variations, leading to more accurate inversion of high ground stress.

[0041] S3: The terrain 3D model is divided into the geological structure modeling area along the tunnel and the geological structure modeling area at the tunnel site.

[0042] The main factors influencing the geological structure modeling area along the tunnel route include faults, densely jointed zones, and the boundary line along the route; the main factors influencing the geological structure modeling area at the tunnel site include faults and densely jointed zones. Dividing the entire modeling area into two major modeling zones facilitates refined modeling, allowing for the generation of more accurate models tailored to the specific geological structures within each zone.

[0043] S4: Generate the first three-dimensional geological model based on the geological structure modeling area along the tunnel; generate the second three-dimensional geological model based on the geological structure modeling area of ​​the tunnel site area;

[0044] The first three-dimensional geological model generates geological structural features in the geological structure modeling area along the tunnel; the second three-dimensional geological model generates geological structural features in the geological structure modeling area of ​​the tunnel site.

[0045] The first three-dimensional geological model is formed after generating faults, dense joint zones, and lithological boundaries in the geological structure modeling area along the tunnel. The second three-dimensional geological model is formed after generating faults and dense joint zones in the geological structure modeling area of ​​the tunnel site.

[0046] See Figure 3 S1 defines the modeling scope of the geological structure model, including:

[0047] S11: Determine the modeling scope of the first geological structure model and screen key geological information based on the tunnel plan construction drawings, tunnel axis profile drawings and engineering geological survey reports;

[0048] Key location information includes: faults, dense joint zones, contour lines, and the mileage and orientation of the tunnel within the geological structure modeling area;

[0049] Screening key geological information helps improve the accuracy of modeling. Screening for faults and densely jointed zones ensures that the geological structure modeling areas along the tunnel route and at the tunnel site can generate corresponding geological structures. Screening for contour lines is to obtain elevation information, generate spatial point clouds, and thus create a 3D terrain model.

[0050] S12: Expand the modeling range of the first geological structure model based on the tunnel length and tunnel orientation to obtain the modeling range of the second geological structure model;

[0051] The modeling scope of the second geological structure model is the defined modeling scope of the first geological structure model. Figure 2As shown, this is a rectangular area defined by the diagonals of the tunnel's starting and ending points. The area of ​​the second geological structure model is as follows. Figure 4 As shown, the area extending beyond the dashed rectangle by the solid line represents the expanded modeling area. Specifically, the area is expanded based on the positions of the tunnel's start and end points. Expanding the modeling area of ​​the first geological structure model to obtain the modeling area of ​​the second geological structure model improves fault tolerance and reduces the impact of boundary effects.

[0052] See Figure 5 , Figure 5 The steps of S2 in generating a 3D terrain model within the modeling scope are shown, including:

[0053] S21: Generate spatial point cloud data for a 3D terrain model based on contour lines;

[0054] Elevation data can be obtained by filtering contour lines. This elevation data serves as a parameter for the curve-dividing function in modeling software. After input, spatial point cloud data of the terrain 3D model can be generated. Spatial point cloud data is a set of coordinates. Based on spatial point cloud data, terrain surfaces can be generated in modeling software, such as... Figure 6 As shown.

[0055] S22: Generate terrain mesh by meshing spatial point cloud data from a 3D terrain model;

[0056] After obtaining all the spatial point cloud coordinates, the terrain mesh is generated using the mesh tiling function in the modeling software. This terrain mesh is a two-dimensional model. At this stage, the mountains have not yet been generated; the generated terrain mesh can only reflect the undulations of the terrain.

[0057] S23: Smooth the terrain mesh and generate a 3D terrain model.

[0058] After smoothing the terrain mesh using a curtain method to create a terrain surface, the model's height is increased after solidifying the terrain surface into a 3D solid. Figure 7 As shown, it is more three-dimensional and realistic. While reflecting the undulating terrain and landforms of the modeled area, it can also further refine the geological structure within the area.

[0059] See Figure 8 , Figure 8The diagram illustrates the geological structure modeling areas along the tunnel and at the tunnel site. To enable more targeted and refined modeling, this embodiment divides the modeling area into two main parts: S3, which divides the 3D terrain model into the geological structure modeling area along the tunnel and the geological structure modeling area at the tunnel site. More specifically, S31: the geological structure modeling area along the tunnel is determined based on the tunnel's radial direction, tunnel orientation, and tunnel axial length; the remaining area is the geological structure modeling area at the tunnel site.

[0060] The area where the tunnel is planned to be constructed is divided into a geological structure modeling zone along the tunnel route, and the remaining area is divided into a geological structure modeling zone for the tunnel site area. This division aims to refine the model and improve its accuracy, thereby providing a more reliable model for inversion of geostress and improving its accuracy. The modeling requirements for the geological structure modeling zone for the tunnel site area and the geological structure modeling zone along the tunnel route are different, and the geological structures affecting them also differ. For the geological structure modeling zone along the tunnel route, faults, dense joint zones, and lithological boundaries are important influencing factors; for the geological structure modeling zone for the tunnel site area, faults and dense joint zones are important influencing factors. Because the tunnel construction needs to be simulated using the geological structure modeling zone along the tunnel route, a more accurate model is required to ensure the accuracy of the simulation. For example… Figure 9 , Figure 9 The detailed modeling of the geological structure modeling area along the tunnel is shown.

[0061] A model reflecting high ground stress is generated by refining the geological structure of the geological structure modeling area along the tunnel and the geological structure modeling area at the tunnel site. This model can then be used to infer actual changes. A first three-dimensional geological model is generated after refining the geological structure of the geological structure modeling area along the tunnel; a second three-dimensional geological model is generated after refining the geological structure of the geological structure modeling area at the tunnel site, including:

[0062] S41: Determine the thickness and modeling location of the fault and the dense joint zone within the geological structure modeling area of ​​the tunnel site based on the tunnel axis profile and the engineering geological survey report;

[0063] The tunnel construction plan only shows the strike of faults and densely jointed zones, but not the changes in dip angle. The tunnel axial profile, however, shows the changes in dip angle of faults and densely jointed zones. Based on the key information selected in S11, the thickness and modeling location of faults and densely jointed zones within the geological structure modeling area of ​​the tunnel site are confirmed. Based on the thickness and location information of faults and densely jointed zones, a refined model of the geological structure modeling area of ​​the tunnel site is performed.

[0064] S42: Perform three-dimensional solidification of the faults and the dense joint zones and Boolean operations to generate a second three-dimensional geological model;

[0065] Within the geological structure modeling area of ​​the tunnel site, a three-dimensional solid model is created based on the thickness and location information of faults and densely jointed zones. The graphics are then processed using Boolean operations in the modeling software to generate a 1:1 refined model of the geological structure modeling area of ​​the tunnel site, which is the second three-dimensional geological model. This final second three-dimensional geological model reflects the orientation of faults and densely jointed zones.

[0066] S43: Based on the tunnel axis profile and the engineering geological survey report, determine the thickness, strike and dip angle of the faults and the dense joint zones within the geological structure modeling area along the tunnel, as well as the location of the lithological boundary line;

[0067] The geological structures requiring detailed modeling within the tunnel's geological structure modeling area include faults, densely jointed zones, and lithological boundaries. Based on the tunnel's axial profile, the thickness, strike, and dip of the faults and densely jointed zones, as well as the location of the lithological boundaries, are observed within the geological structure modeling area along the tunnel. Based on this information, a detailed model of the geological structure modeling area along the tunnel is then performed.

[0068] S44: Based on the dip angle and strike, the faults and dense joint zones are solidified into three dimensions and Boolean operations are performed; Boolean operations are performed on the lithological boundaries to generate the first three-dimensional geological model.

[0069] Within the geological structure modeling area along the tunnel, three-dimensional solidification is performed based on the thickness and location information of faults, densely jointed zones, and lithological boundaries. The graphics are then processed using Boolean operations in the modeling software to generate a 1:1 refined model of the geological structure modeling area along the tunnel—the first three-dimensional geological model. This final first three-dimensional geological model reflects the strike and dip changes of faults, densely jointed zones, and lithological boundaries.

[0070] After generating the first and second 3D geological models, the locations, thicknesses, and dip angles of the generated faults, dense joint zones, and lithological boundaries are checked. If discrepancies are found between the refined model and the tunnel construction plan, tunnel axis profile, and the aforementioned engineering geological survey report, the discrepancies are corrected using Boolean operations. The final result is a 1:1 scale model. Figure 10 As shown.

[0071] To enable model recognition in inversion software, the established model needs to be meshed. For fine-grained modeling locations such as faults, densely jointed zones, and lithological boundaries, local mesh refinement is required to prevent distortion and improve modeling accuracy. However, local refinement can lead to discontinuities in the mesh between the mountain and fault / densely jointed zones, necessitating re-meshing to ensure mesh continuity. Furthermore, the embodiments provided in this application convert all non-manifold meshes into manifold meshes, ensuring smooth surface and volume mesh generation and further reducing compatibility issues between software programs.

[0072] After mesh refinement processing of faults, densely jointed zones, and lithological boundaries, the first and second three-dimensional geological models exhibit the same mesh size for faults and densely jointed zones, while the mesh size for the remaining terrain features is consistent. For example, in the embodiment provided in the application, faults and densely jointed zones in the fine-grained area are each 25 meters apart, as are those in the non-fine-grained area, while the remaining mountain sections, including lithological boundaries, are each 100 meters apart.

[0073] Export the generated mesh file to the inversion software and open the model in the software. Group the different lithological regions according to the engineering geological survey report, and assign parameters to faults, densely jointed zones, and different rock types. After parameter assignment, invert the high ground stress using the boundary load adjustment method in the inversion software. After the inversion is complete, inversion values ​​will be obtained. Measured values ​​can be obtained from the geological survey report. The inversion accuracy can be obtained using the following formula:

[0074] δ=(X 实测 -X 反演 ) / X 实测

[0075] If the accuracy δ is greater than or equal to 85%, it indicates that the modeling is reasonable and the inversion is correct.

[0076] By refining the modeling of geological structures that influence high ground stress, the accuracy of inversion can be improved. This reduces the high cost of deep borehole testing and enables the simulation of actual terrain through the generated model.

[0077] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0078] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0079] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0080] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0081] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A geological structure modeling method for refining tunnel geological structures and dynamically inverting three-dimensional geostress fields, characterized in that, include: S1: Determine the modeling scope of the geological structure model; S2: Generate a 3D terrain model within the modeling area; S3: The terrain 3D model is divided into a geological structure modeling area along the tunnel and a geological structure modeling area at the tunnel site. S4: Generate a first three-dimensional geological model based on the geological structure modeling area along the tunnel; generate a second three-dimensional geological model based on the geological structure modeling area of ​​the tunnel site area; The first three-dimensional geological model generates geological structural features in the geological structure modeling area along the tunnel; the second three-dimensional geological model generates geological structural features in the geological structure modeling area of ​​the tunnel site. S41: Determine the thickness and modeling location of faults and dense joint zones within the geological structure modeling area of ​​the tunnel site based on the tunnel axis profile and the engineering geological survey report; S42: Perform three-dimensional solidification of faults and dense joint zones and Boolean operations to generate the second three-dimensional geological model; S43: Based on the tunnel axis profile and the engineering geological survey report, determine the thickness, strike and dip angle of faults and dense joint zones, as well as the location of lithological boundaries within the geological structure modeling area along the tunnel. S44: Based on the dip angle and strike, the faults and dense joint zones are solidified into three dimensions and Boolean operations are performed; Boolean operations are performed on the lithological boundaries to generate the first three-dimensional geological model.

2. The geological structure modeling method according to claim 1, characterized in that, The modeling scope of the geological structure model includes: S11: Determine the modeling scope of the first geological structure model and screen key geological information based on the tunnel plan construction drawings, tunnel axis profile drawings and engineering geological survey reports; The key address information includes: faults, dense joint zones, contour lines, and tunnel mileage and orientation within the modeling range of the geological structure model; S12: Expand the modeling range of the first geological structure model according to the tunnel length and tunnel orientation to obtain the modeling range of the second geological structure model; The modeling range of the second geological structure model is the determined modeling range of the geological structure model.

3. The geological structure modeling method according to claim 2, characterized in that, The generation of the 3D terrain model within the modeling scope includes: S21: Generate spatial point cloud data of the terrain 3D model based on the contour lines; S22: Generate a terrain mesh from the spatial point cloud data mesh of the three-dimensional terrain model; S23: Smooth the terrain mesh and generate a 3D terrain model.

4. The geological structure modeling method according to claim 3, characterized in that, The geological structure modeling area along the tunnel and the geological structure modeling area at the tunnel site are divided into two parts within the three-dimensional terrain model: S31: The geological structure modeling area along the tunnel is determined based on the radial direction and axial length of the tunnel, and the remaining area is the geological structure modeling area of ​​the tunnel site.

5. The geological structure modeling method according to claim 4, characterized in that, The geological structural features include faults, densely jointed zones, and lithological boundaries.

6. The geological structure modeling method according to claim 5, characterized in that, After generating the first three-dimensional geological model based on the geological structure modeling area along the tunnel and the second three-dimensional geological model based on the geological structure modeling area of ​​the tunnel site, the method further includes: performing mesh refinement processing on the geological structure features.

7. The geological structure modeling method according to claim 5, characterized in that, The faults and dense joint zones in the first and second three-dimensional geological models, after the geological structural features have been densified into grids, have the same grid size, and the remaining terrain grids have the same size.

8. The geological structure modeling method according to claim 6, characterized in that, The process of refining the geological structure features by mesh also includes: an accuracy assessment of the comparison between the inverted in-situ stress values ​​and the measured values ​​from boreholes; The accuracy assessment is based on the formula: δ = (X 实测 -X 反演 ) / X 实测 ; If the accuracy δ is greater than or equal to 85%, it indicates that the modeling is reasonable and the inversion is correct.

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