A method for fine-grained three-dimensional stratigraphic modeling of fault zones in karst areas

Abstract

The present invention proposes a method for fine modeling of three-dimensional strata in a karst fault zone, which includes using ArcGIS software to establish a simple database for a study area; integrating borehole data sets, and performing horizon numbering according to the order of stratum characterization; importing the borehole data into GMS in sequence according to the horizon number, and creating and modifying shp files in ArcGIS according to geological knowledge to accurately control the stratum fluctuation; converting the corresponding shp files into Raster files, and importing them into GMS in a specific format to create a Raster Catalog; using the Raster Catalog module, and selecting a suitable interpolation method to generate the corresponding Solid, if its fluctuation does not conform to the actual situation, continue to adjust; and continuously accumulating soild to generate the final three-dimensional geological structure model. The present invention hierarchically edits and stores the three-dimensional point data after the fusion processing of the borehole data and the geological profile based on ArcGIS spatial information integration technology, and then uses the RasterCatalog module in GMS to accurately and flexibly establish a three-dimensional geological structure model.

Description

Technical Field

[0001] The invention belongs to the technical field of three-dimensional geological modeling, and in particular relates to a method for fine-grained three-dimensional stratum modeling of a fault zone in a karst area. Background Art

[0002] Due to the complex engineering geological conditions, high ground stress, and karst development in the southwest region, water inrush accidents are very likely to occur during the construction of engineering tunnels, especially those crossing fault fracture zones. Such accidents occur suddenly and are destructive, so the prediction and calculation of tunnel water inrush is particularly important in the early stages of construction. When using numerical simulation methods to calculate tunnel water inrush, due to the development of karst and complex fault structure in the study area, the accuracy of using only conventional methods (creating borehole cross sections to generate a three-dimensional geological structure model) is not high, and it is difficult to control the occurrence of the main faults. Therefore, in response to the above problems, it is necessary to propose a high-precision and flexible three-dimensional geological modeling method. Summary of the invention

[0003] Purpose of the invention: The main purpose of the present invention is to provide a method for fine-tuning three-dimensional stratigraphic modeling of fault zones in karst areas, which can accurately and flexibly establish a three-dimensional geological structure model.

[0004] Technical solution: To achieve the above purpose, the present invention provides a method for fine-tuning three-dimensional stratigraphic modeling of fault zones in karst areas, the method comprising the following steps:

[0005] Step 1: Collect relevant geological data of the study area and establish a geological data database using ArcGIS software to determine the scope of the study area;

[0006] Step 2: Based on the established geological data database and in combination with the engineering geological report, the stratum distribution and geological structure characteristics of the study area are analyzed, the study area is divided into different plots and their characterization order is determined, and then all the strata in each plot are numbered in the order from bottom to top;

[0007] Step 3: Import the drilling data into GMS in sequence according to the Horizon number, and create and modify the attachment of the points in the shp file in ArcGIS software according to geological knowledge to depict the stratum undulation;

[0008] Step 4: Convert the stratum shp file into a Raster file and import it into GMS in a specific format to create a Raster Catalog;

[0009] Step 5: Generate the corresponding Solid using Raster Catalog. If the undulation does not meet the actual requirements, continue to modify the shp file in step 3 for adjustment. If it meets the actual requirements, repeat steps 3, 4, and 5 to depict the next stratum until all strata are depicted.

[0010] Step 6: Generate the final 3D geological structure model by continuous accumulation of soild.

[0011] Furthermore, in step 1, after the geological plan, cross-section, and drilling data are pre-processed by setting the coordinate system and position calibration, they are imported into ArcGIS software, and the stacking order of the layer combination is adjusted according to the needs of the image display, thereby forming a geological data database.

[0012] Furthermore, in the step 2: the study area is divided into blocks for modeling, and the first block to be characterized is determined according to the characteristics of the oldest stratigraphic age and the number of adjacent blocks being 1, and then the adjacent block is characterized in the second order, and so on, so as to determine the characterization order of all blocks.

[0013] Furthermore, the step 3 comprises:

[0014] S31, starting from 1 according to the Horizon value, only the lithology data of the corresponding borehole with a Horizon value of 1 is inserted into the GMS, and the remaining lithology data in the same borehole and other boreholes are not inserted. When the Horizon value is i, where i>1, only the lithology data of the corresponding borehole with a Horizon less than or equal to i is inserted into the GMS;

[0015] S32, matching the drilling data with the geological profile, and fusing and extracting the corresponding stratum upper surface elevation point data according to different horizon values, and storing them in shp file format, the point attributes include: feature ID "FID", feature type "Shape", data source label "LABEL", coordinate values ​​"X", "Y", "Z" and elevation value "ELE";

[0016] S33. In locations where drilling data is lacking, encryption is performed by manually adding nodes, and the stratigraphic morphology is accurately depicted by modifying the node attributes. The fault zone is also processed according to the stratigraphic depiction method.

[0017] Furthermore, the step 4 comprises:

[0018] S41, using the stratum shp file to generate a TIN triangulated mesh using the Create TIN tool in the data management tool under the 3D Analyst tool;

[0019] S42. Use the TIN to Raster tool under the conversion tool to convert to a Raster file;

[0020] S43. Import the Raster file into GMS in the "﹡.tiff" format and right-click to create a Raster Catalog;

[0021] S44. Double-click Raster Catalog to open the edit bar and select the corresponding Raster file, stratigraphic lithology, and horizon value in the order of characterization, and check Fill.

[0022] Furthermore, the step 5 comprises:

[0023] S51. Right-click Raster Catalog and select Horizons → Solid tool. In the edit bar, pull down and select the created Raster Catalog.

[0024] S52, select the upper surface elevation, bottom elevation, and interpolation method according to the actual situation, and generate the corresponding Solid;

[0025] S53. If structural adjustment is still needed after the three-dimensional geological structure modeling is completed, select the shp file of the corresponding stratum for modification.

[0026] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0027] The present invention proposes a method for fine modeling of three-dimensional strata in karst fault zones. The three-dimensional point data attached after the fusion processing of drilling data and geological profiles is modified by ArcGIS spatial information integration technology to accurately control the ups and downs of different strata. Each stratum is controlled by an independent shp file. If structural adjustment is still required after the three-dimensional geological structure modeling is completed, the shp file of the corresponding stratum can be selected for modification. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of three-dimensional geological modeling in the present invention;

[0029] Figure 2 It is a general diagram of the case engineering in the present invention;

[0030] Figure 3 It is a schematic diagram of the attachment of the shp file point in the present invention;

[0031] Figure 4 This is a schematic diagram of importing a Raster file in the present invention;

[0032] Figure 5It is a schematic diagram of editing Raster Catalog in the present invention;

[0033] Figure 6 The present invention uses Raster Catalog to generate a Solid process diagram;

[0034] Figure 7 It is a schematic diagram of block modeling of three-dimensional geological structure in the present invention. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to the accompanying drawings and specific implementation examples.

[0036] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same technical meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0037] like Figures 1 to 7 As shown, the present invention provides a 3D geological modeling method, which edits and stores the 3D point data after the fusion processing of the drilling data and the geological profile based on ArcGIS spatial information integration technology, and then uses the Raster Catalog module in GMS to accurately and flexibly establish a 3D geological structure model.

[0038] The present invention provides a method for finely modeling three-dimensional strata in a karst fault zone. The technical roadmap of the method is as follows: Figure 1 As shown, the specific steps include:

[0039] Step 1: Collect geological data, establish a simple database using ArcGIS software, and determine the scope of the study area. Figure 2 .

[0040] Step 2. Based on the existing geological plan, geological profile and drilling data in the study area, firstly, according to the characteristics of the Lime Kiln Fault in the study area, which is nearly EW in trend and dips north, and the Huangfengchang-Qingshuijiang Fault in trend NNE and dips NWW, the geological structure is depicted in the order of strata on the south side of the Lime Kiln Fault → Lime Kiln Fault → strata on the north side of the Lime Kiln Fault → Huangfengchang-Qingshuijiang Fault → strata on the west side of the Huangfengchang-Qingshuijiang Fault. Then, the strata in the study area are subdivided into 28 layers according to the depiction order and the horizons are numbered.

[0041] Step 3: Due to the cost of mountain projects, the number of boreholes is small. According to the data format required by the Borehole Date module, 132 borehole data are prepared, including 77 actual boreholes and 55 virtual boreholes. The borehole data are imported into GMS in sequence according to the Horizon number of the lithology from 1 to 28. At the same time, the shp file is created and modified in ArcGIS software according to geological knowledge to accurately depict the stratum undulation. Figure 3 This is a schematic diagram of the attachment of the 3D point data of the stratigraphic part when Horizon=7. The data sources mainly include drilling data, geological planes, and manual additions based on geological knowledge.

[0042] Step 4: Use the Create TIN tool in the Data Management tool under the 3D Analyst tool to generate a TIN triangulated mesh from the stratum shp file. Then use the TIN to Raster tool under the Conversion tool, select NATURAL_NEIGHBORS for the method and OBSERVATIONS 50 for the sampling distance, and import the generated Raster file into GMS in the *.tiff format. Figure 4 Select the Raster file and right-click the New Raster Catalog tool to generate a new Raster Catalog (1). Double-click Raster Catalog (1) to open the edit bar and select the corresponding Raster file and stratum lithology according to the characterization order (Horizon value from 1 to 28), check Fill, see Figure 5 ;

[0043] Step 5: Generate the corresponding Solid using Raster Catalog (1). If you are not satisfied, continue to modify the shp file in S3 to make adjustments. If you are satisfied, repeat all the steps in S3 to depict the next stratum soild.

[0044] Step 6. Right-click Raster Catalog (1) and select Horizons → Solid Tools. In the RasterCatalog drop-down list in the edit bar, select the created Raster Catalog (1). Figure 6 On the next page, select TINelevations for Top elevation, select Constant elevation value of 1800m for Bottom elevation, select Inversedistance weighted for interpolation method, and select Constant for Nodal function. The generated 3D geological structure model is shown in Figure 7 .

Claims

1. A method for fine-tuning three-dimensional stratigraphic modeling of a fault zone in a karst area, characterized in that: The method comprises the following steps: Step 1: Collect relevant geological data of the study area and establish a geological data database using ArcGIS software to determine the scope of the study area; Step 2: Based on the established geological data database and in combination with the engineering geological report, the stratum distribution and geological structure characteristics of the study area are analyzed, the study area is divided into different plots and their characterization order is determined, and then all the strata in each plot are numbered in the order from bottom to top; Step 3: Import the drilling data into GMS in sequence according to the Horizon number, and create and modify the attachment of the points in the shp file in ArcGIS software according to geological knowledge to depict the undulating morphology of the strata; Step 4: Convert the stratum shp file into a Raster file and import it into GMS in a specific format to create a RasterCatalog; Step 5: Generate the corresponding Solid using Raster Catalog. If the undulation does not meet the actual requirements, continue to modify the shp file in step 3 for adjustment. If it meets the actual requirements, repeat steps 3, 4, and 5 to depict the next stratum until all strata are depicted. Step 6: Generate the final 3D geological structure model by continuous accumulation of soild; In the step 2, the study area is divided into blocks for modeling, and the first block to be characterized is determined according to the characteristics of the oldest stratigraphic age and the number of adjacent blocks being 1, and then the adjacent block is characterized in the second order, and so on, thereby determining the characterization order of all blocks; The step 3 comprises the following steps: S31, starting from 1 according to the Horizon value, only the lithology data of the corresponding borehole with a Horizon value of 1 is inserted into the GMS, and the remaining lithology data in the same borehole and other boreholes are not inserted, and when the Horizon value is i, only the lithology data of the corresponding borehole with a Horizon less than or equal to i is inserted into the GMS, where i>1; S32, matching the drilling data with the geological profile, and fusing and extracting the corresponding stratum upper surface elevation point data according to different horizon values, and storing them in shp file format, the point attributes include: feature ID "FID", feature type "Shape", data source label "LABEL", coordinate values ​​"X", "Y", "Z" and elevation value "ELE"; S33. In locations where drilling data is lacking, encryption is performed by manually adding nodes, and the stratigraphic morphology is accurately depicted by modifying the node attributes. The fault zone is also processed according to the stratigraphic depiction method.

2. The method for fine-tuning three-dimensional stratigraphic modeling of a fault zone in a karst area according to claim 1, characterized in that: In the step 1, after the geological plan, profile, and drilling data are pre-processed by setting the coordinate system and position calibration, they are imported into ArcGIS software, and the stacking order of the layer combination is adjusted according to the needs of the image display, thereby forming a geological data database.

3. The method for fine-tuning three-dimensional stratigraphic modeling of a fault zone in a karst area according to claim 1, characterized in that: The step 4 comprises: S41, using the stratum shp file to generate a TIN triangulated mesh using the Create TIN tool in the data management tool under the 3D Analyst tool; S42. Use the TIN to Raster tool under the conversion tool to convert to a Raster file; S43. Import the Raster file into GMS in the "﹡.tiff" format and right-click to create a Raster Catalog; S44. Double-click Raster Catalog to open the edit bar and select the corresponding Raster file, stratigraphic lithology, and horizon value in the order of characterization, and check Fill.

4. The method for fine-tuning three-dimensional stratigraphic modeling of a karst fault zone according to claim 1, characterized in that: The step 5 comprises: S51. Right-click Raster Catalog and select Horizons → Solid tool. In the edit bar, pull down and select the created Raster Catalog. S52, selecting the upper surface elevation, the bottom elevation, and the interpolation method according to the actual situation to generate the corresponding Solid; S53. If structural adjustment is still needed after the three-dimensional geological structure modeling is completed, select the shp file of the corresponding stratum for modification.

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