A method for modeling topsoil layer based on microstation attribute recognition

Abstract

The application discloses a topsoil stratum modeling method based on MicroStation attribute identification and relates to the cross field of geological survey and computer-aided design. The application creates a three-dimensional model of a borehole in MicroStation, projects an orifice coordinate to a plane, adopts a BowyerWatson algorithm to perform Delaunay triangulation, and constructs a borehole profile triangular net. After manual adjustment, the strata are automatically connected according to corresponding rules, and the triangular area space is closed. Then, the stratum profile is generated into a geobody model along the elevation, the lens structure is subjected to shearing treatment, and finally, a complete three-dimensional topsoil geological model is formed. The application realizes three-dimensional visual expression of the topsoil stratum, can be arbitrarily cut and viewed, and only needs to be partially reconstructed when new survey data is added, so that the modeling workload is greatly reduced, the accuracy and updating efficiency of the geological model are improved, and an intuitive and reliable geological basis is provided for geotechnical engineering design and construction.

Description

Technical Field

[0001] This invention relates to the interdisciplinary field of geological exploration and computer-aided design, and in particular to a topsoil stratum modeling method based on MicroStation attribute recognition. Background Technology

[0002] For surface geological exploration projects, geological models, as an important appendix to the exploration report, are used to directly illustrate the stratigraphic situation and provide geological basis for subsequent geotechnical engineering design and construction. The quality of the geological model directly affects the safety, cost, and quality of the project. Currently, exploration results are generally presented by combining exploration point plans and geological profiles. Geological profiles require exploration engineers to make reasonable inferences about the stratigraphy based on the results of drilling, geophysical exploration, and static exploration, and according to various geological engineering theories and specifications, before drawing the profile. This two-dimensional drawing method is not intuitive enough, and exploration engineers without professional training find it difficult to draw reasonable profiles. Furthermore, design and construction personnel are prone to misunderstandings of the drawings.

[0003] Furthermore, when new field exploration results are added, it is necessary to re-plan the profiles on the exploration point plan and redraw the geological profiles based on them, which is a significant workload. Moreover, profiles can influence each other, but the current two-dimensional method of drawing profiles cannot intuitively show the mutual influence between intersecting profiles, leading to inconsistencies in the profiles that are difficult to identify. The three-dimensional geological model created based on MicroStation incorporates borehole coordinates, stratigraphic lithology, and start and end depths obtained from exploration results as attributes attached to the model. New borehole, geophysical, and static exploration results, after being converted into a three-dimensional model, also possess these attributes. Based on this, new exploration results can be intuitively controlled, and adjacent exploration results can be connected using the algorithm of this invention to form new three-dimensional geological profiles. This three-dimensional representation reflects the connections between intersecting profiles, making the geological model drawn based on new exploration results more reasonable. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a topsoil stratum modeling method based on MicroStation attribute recognition. By reading and recognizing the stratum attribute data carried by the borehole model, and combining triangulation and automatic layer connection algorithms, it achieves efficient, accurate, and locally updatable three-dimensional modeling of topsoil strata.

[0005] To achieve the above objectives, this application adopts the following technical solution: This invention uses Windows 10 as the operating system, Microsoft Visual Studio 2017 as the development environment, C# language, and is developed based on MicroStation SDK Update 12 and PROJ.4 4.9.3. It uses SQL Server to store data such as borehole coordinates, stratigraphic layers, lithology, physical and mechanical parameters, stratigraphic color, and construction time.

[0006] A topsoil stratigraphic modeling method based on MicroStation attribute identification includes the following steps: S1: Create the drilling model and triangulate it. Create a 3D borehole model with formation attributes in MicroStation, project the borehole coordinates onto the XY plane at Z=0, and use Bowyer... The Watson algorithm performs Delaunay triangulation on the projection points to generate a borehole profile triangulation network. When the borehole model is created, it loads stratigraphic attributes such as borehole coordinates, formation depth, lithology, and physical and mechanical parameters to provide data support for subsequent automatic profile layer connection and closure determination.

[0007] S2: Manually adjust the triangular mesh Manually adjust the triangulation network by deleting or adding profile lines to ensure that the triangulation network has no intersecting edges or hanging edges, and save it to the database. S3: Automatic Profile Layering Automatic profiling and layering are performed on adjacent boreholes according to the preset stratigraphic connection angle threshold. The pinch-out, one-to-one correspondence, one-to-many, inclusion, and staggered situations are handled according to the stratigraphic correspondence. The layering follows the principle of minimizing the number of pinch-outs within the threshold.

[0008] S4: Closure Check and Correction Check the sealing of the space enclosed by the three borehole profiles within the triangular area. If it is not sealed, adjust the number of tipping points to achieve sealing. S5: Manual fine-tuning of the profile Manual fine-tuning is performed on closed profiles, adjusting only the profile lines corresponding to pinch-outs to ensure the rationality of the formation logic.

[0009] S6: Generate Terrain Model Generate a terrane model from the closed stratigraphic profile within the triangular region along the elevation from top to bottom; S7: Lens Body Processing Shearing is performed on the land terrane model with inclusion relationships to generate a lens structure, which is then stitched together to obtain a complete three-dimensional geological model of the topsoil layer.

[0010] Furthermore, the attributes carried by the borehole model in step S1 include the three-dimensional coordinates of the borehole opening, formation depth, lithology, physical and mechanical parameters, formation color, and construction time.

[0011] Furthermore, in step S3, the preset angle threshold is the maximum value of the angle between the stratum dividing line and the horizontal.

[0012] Furthermore, the stratigraphic connection rules in step S3 include: (1) The two boreholes have no identical formations, so a pinch-out is set; (2) The strata of the two boreholes correspond one-to-one and are directly connected; (3) Two boreholes form a one-to-many formation, creating a large layer containing smaller layers; (4) Two boreholes with the same number contain the same sub-layers within the strata, and are connected according to the corresponding strata; (5) When the strata of the two boreholes are intersecting, connect the middle position of the same strata and decompose them into the basic case.

[0013] Furthermore, in step S5, manual fine-tuning only allows modification of pinch-out morphology, dip angle, and location; profile lines must not intersect, and strata must not be reversed.

[0014] Furthermore, in step S7, the lens body processing employs Boolean shearing to hollow out the internal small strata that occupy space in order to form a lens body, interlayer, or wedge.

[0015] Furthermore, when adding new exploration data, only local profile reconnection and model reconstruction are performed on the affected triangular area, without altering the global model.

[0016] Furthermore, the constructed three-dimensional geological model supports three-dimensional cross-section at any location and angle, and allows for real-time querying of stratigraphic properties.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Three-dimensional geological models can intuitively display geological conditions, and any part of the model can be cut and displayed. This allows non-professionals to quickly and comprehensively understand the geological situation.

[0018] 2. As exploration work continues to advance, various exploration results such as drilling, geophysical exploration, and static exploration are constantly increasing. Based on Delaunay triangulation, the area affected by newly inserted boreholes can be reconnected and the model reconstructed, which can significantly reduce the workload compared to drawing two-dimensional profiles.

[0019] 3. Based on the three-dimensional geological model, it is possible to perform three-dimensional cross-sections at any location, allowing for a direct and three-dimensional view of the three-dimensional geological conditions at any location and angle within the engineering site. Attached Figure Description

[0020] Figure 1 Overall flowchart of the invention; Figure 2 Example: Drilling model diagram; Figure 3 Example: Drilling profile diagram; Figure 4 Example: Bowyer Watson algorithm flowchart; Figure 5 Example: Manually adjust the cross-sectional interface; Figure 6 Example: Formation connection angle setting interface; Figure 7 The example does not have a schematic diagram of the pinch-out of the same strata; Figure 8 : Schematic diagram of one-to-one correspondence between strata in the example; Figure 9 Example: Schematic diagram of a one-to-many formation; Figure 10 : Schematic diagram of the same sub-layers within the same stratum in the example; Figure 11 : Schematic diagram of different sublayers within the same stratum in the example; Figure 12 Example: Schematic diagram of the intermediate connecting lines of the intersecting strata; Figure 13 Example 3: Drilling and sealing results diagram; Figure 14 Example: Manually adjust the cross-sectional interface; Figure 15 Overall cross-sectional view of the embodiment; Figure 16 : Schematic diagram of terrain model generation in the example; Figure 17 : Schematic diagram of lens body generation in the embodiment; Figure 18 : Final three-dimensional geological model of the embodiment. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] Example The present invention will be further described in detail below with reference to the accompanying drawings. This embodiment uses Windows 10 as the operating system, Microsoft Visual Studio 2017 as the development environment, C# programming language, and MicroStation SDKUpdate12 and PROJ.4 4.9.3 development packages for development. A SQL Server database is used to store exploration data such as borehole coordinates, formation depth, lithology, physical and mechanical parameters, formation color, and construction time.

[0023] Step 1: Data Reading and Drilling 3D Model Creation 1. Data Loading The DrillHoleLayer.ReadDrillHoleLayer method reads exploration data from the SQL Server database and stores it in the DrillHoleLayers collection. Each stratigraphic data entry includes: borehole 3D coordinates, stratigraphic depth, lithology name, water content, compression modulus, cohesion, internal friction angle, stratigraphic color, and borehole construction time.

[0024] 2. Create the borehole geometry model Iterate through the DrillHoleLayers collection, call the CreateDrillHoleGeo method, starting from the borehole coordinates and extending downwards according to the formation thickness to generate a cylindrical or columnar three-dimensional borehole geometry drillHoleGeo, and add it to the drillHoleGeos collection.

[0025] 3. Load the MicroStation model Retrieve the current active model (dgnModel) of the DGN file, iterate through drillHoleGeos, instantiate a DrillHoleElement and call the AddToModel method to display the borehole model in the MicroStation view, forming a model like... Figure 2 The three-dimensional model of the borehole is shown.

[0026] Step 2: Orifice Projection and Delaunay Triangulation 1. Plane projection of the orifice Traverse all borehole models, extract the X and Y coordinates of the borehole opening, set the Z coordinate to 0, generate a two-dimensional projection point DPoint3d, and store it in the collarPoints collection to complete the projection of the borehole opening onto the Z=0 XY plane.

[0027] 2. Construction of the triangular network like Figure 4As shown, the Bowyer-Watson algorithm is used to perform Delaunay triangulation on collarPoints: a super triangle containing all projected points is constructed; points are inserted one by one, the relationship between the point and the circumcircle of the triangle is determined, the triangle containing the point is deleted, a cavity is formed and reconnected; triangles containing vertices of the super triangle are removed, and a valid triangulation is output, resulting in the following: Figure 3 The drill profile triangular mesh shown.

[0028] 3. Triangular network storage The vertex numbers, edge relationships, and triangle indices of the triangulation network are written into the database for subsequent cross-sectional layering and model reconstruction.

[0029] Step 3: Manually adjust the borehole profile triangular mesh Through such Figure 5 Perform editing operations on the interactive interface shown: 1. Locate the drill hole: Select the target drill hole in the "Search Drill Holes" drop-down list and move the drill hole to the center of the interface; 2. Edit section lines: (1) Delete section lines: Click "Delete section lines" and click the mouse to delete the incorrect connection; (2) Connect section lines: Click "Connect section lines" and select two boreholes to generate a new section; 3. Legality verification: The system automatically checks whether the triangulation network is fully covered, without intersections, and without hanging edges. The "OK" button can only be enabled after the verification is passed. 4. Save Results: Click OK to save the adjusted topology to the database.

[0030] Step 4: Set parameters and automatically connect layers in the profile. 1. Parameter Configuration Open as Figure 6 In the interface, set the maximum angle between the stratigraphic dividing line and the horizontal line (30°–60° recommended) as a threshold for constraining the rationality of stratigraphic connections.

[0031] 2. Automatic layer connection according to rules Traverse the two holes corresponding to each edge of the triangular mesh, and connect the layers according to the following cases: (1) No common formation: When two boreholes have no common formation, the formation (contact position) is set as pinch-out, and the result is as follows. Figure 7 ; (2) One-to-one correspondence: When the strata between two boreholes correspond one-to-one (stratum number and lithology are consistent), the strata are connected one-to-one, and the result is as follows. Figure 8 ; (3) One-to-many: When there is a one-to-many relationship between the formations on one side and the formations on the other side between two boreholes, a situation is formed in which a large layer contains several pinch-outs, as shown in the following figure. Figure 9 ; (4) Sub-layers within the same layer: When the same numbered strata in two boreholes both contain other strata: Assume that the major layer number of the same strata in the two boreholes is ②.

[0032] Scenario 1: Both boreholes contain strata with the same number in stratum ②. That is, there are sub-strata within the same numbered strata. If there are identical sub-strata, they are connected, as shown in Figure 10.

[0033] Scenario 2: If there are no identically numbered strata within formation ② in either borehole, then the strata with the same number contain sub-strata; otherwise, they are connected as a whole. Figure 11 ; (5) Stratigraphic Interleaving: The stratigraphic numbers of the two boreholes are interleaved, and the lines connecting the middle positions of the same stratigraphic layers between the two boreholes are as follows: Figure 12 .

[0034] within no more than Figure 6 Under the threshold set in the [reference needed], the number of pinch-outs in the cross-sectional image should be minimized. Based on this principle, [the following will be implemented]. Figure 12 The complex cross-sectional diagram is decomposed into Figures 7-11 In this case, then connect the layers.

[0035] 3. Space sealing inspection and correction After the layers are connected, the cross-sections of the three boreholes corresponding to each triangle are used to enclose a space for a sealing check: if sealed, proceed to the next step; if not sealed, adjust the last cross-section of each triangular region according to the previous step, increasing the number of pinch-outs to force the space to close, forming a shape like... Figure 13 The three-hole closed profile is shown.

[0036] Step 5: Manually fine-tune the stratigraphic profile Through such Figure 14 The interface has been finely adjusted: 1. Select two adjacent boreholes, load the generated automatic layered profile, and display the corresponding profile in the interface; 2. In this profile, users can manually adjust the stratum profile lines, only allowing adjustment of the profile lines corresponding to pinch-outs, and dragging the pinch-out vertices to modify their shape, dip angle, and position; 3. The system verifies in real time that the profile lines do not intersect and the strata do not reverse; 4. Save the settings after adjustment to get the result as shown below. Figure 15 The overall optimal profile is shown.

[0037] Step 6: Generating the triangular region terrain model 1. Create a geological model by connecting the stratigraphic profiles on the three sections one by one along the elevation from top to bottom for each triangular region; 2. Generate a three-dimensional terrain body by lofting / skinning the closed contour lines of the same stratum on the three borehole profiles; 3. Assign corresponding colors and properties according to lithology, forming... Figure 16 The shown is a geological entity model.

[0038] Step 7: Lens cutting and model integration 1. Detect the inclusion relationships between terranes and identify lenses, interlayers, and wedges; 2. Boolean shearing is applied to the external strata, hollowing out the internal smaller strata to occupy space and forming a lenticular structure, such as... Figure 17 ; 3. Traverse all triangular regions, complete the cutting and splicing, and obtain the following: Figure 18 The complete three-dimensional geological model of the topsoil layer is shown.

[0039] Step 8: Model Update and Section Application 1. Incremental update: When adding a new borehole, only the affected area is re-subdivided, locally reconnected and reconstructed, without changing the global model; 2. 3D sectioning: Supports sectioning on any plane and at any angle, and displays stratum thickness, lithology, burial depth and physical parameters in real time; 3. Attribute Query: Click anywhere on the model to read all the auxiliary attributes such as borehole, formation, lithology, and parameters.

[0040] The above description is only a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of this application should be included within the scope of protection of this application.

Claims

1. A topsoil stratigraphic modeling method based on MicroStation attribute recognition, characterized in that, Includes the following steps: S1. Create a borehole model and triangulate it: Create a 3D borehole model with formation attributes in MicroStation, project the borehole coordinates onto the XY plane with Z=0, and use the Bowyer-Watson algorithm to perform Delaunay triangulation on the projection points to generate a borehole profile triangulation network. S2. Manually adjust the triangular mesh: Manually adjust the triangular mesh, delete or add profile lines, ensure that the triangular mesh has no intersecting edges and no hanging edges, and save it to the database; S3. Automatic profiling and layering: Automatic profiling and layering is performed on adjacent boreholes according to the preset stratigraphic connection angle threshold. The pinch-out, one-to-one correspondence, one-to-many, inclusion, and staggered situations are handled according to the stratigraphic correspondence. The layering follows the principle of minimizing the number of pinch-outs within the threshold. S4. Sealing Inspection and Correction: Check the sealing of the space enclosed by the three borehole profiles within the triangular area. If it is not sealed, adjust the number of tipping points to achieve sealing. S5. Manual fine-tuning of the profile: Perform manual fine-tuning on the closed profile, only adjusting the profile line corresponding to the pinch-out, to ensure that the formation logic is reasonable; S6. Generate Terrain Model: Generate a terrain model from the closed stratigraphic profile within the triangular region along the elevation from top to bottom; S7. Lens processing: Perform shearing processing on the land model with inclusion relationships to generate a lens structure, and stitch them together to obtain a complete three-dimensional geological model of the topsoil layer.

2. The method according to claim 1, characterized in that: The attributes carried by the borehole model in step S1 include the three-dimensional coordinates of the borehole opening, formation depth, lithology, physical and mechanical parameters, formation color, and construction time.

3. The method according to claim 1, characterized in that: In step S3, the preset angle threshold is the maximum value of the angle between the stratum dividing line and the horizontal.

4. The method according to claim 1, characterized in that: The stratigraphic connection rules in step S3 include: (1) The two boreholes have no identical formations, so a pinch-out is set; (2) The strata of the two boreholes correspond one-to-one and are directly connected; (3) Two boreholes form a one-to-many formation, creating a large layer containing smaller layers; (4) Two boreholes with the same number contain the same sub-layers within the strata, and are connected according to the corresponding strata; (5) When the strata of the two boreholes are intersecting, connect the middle position of the same strata and decompose them into the basic case.

5. The method according to claim 1, characterized in that: In step S5, manual fine-tuning only allows modification of pinch-out morphology, dip angle, and location; profile lines must not intersect and strata must not be reversed.

6. The method according to claim 1, characterized in that: In step S7, the lens body processing employs Boolean shearing to hollow out the internal small strata that occupy space in order to form a lens body, interlayer, or wedge.

7. The method according to claim 1, characterized in that: When adding new survey data, only local profile reconnection and model reconstruction are performed on the affected triangular area, without changing the global model.

8. The method according to claim 1, characterized in that: The constructed 3D geological model supports 3D cross-section at any location and angle, and allows for real-time querying of stratigraphic properties.

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