Construction method of large-area three-dimensional geological visualization model

Abstract

The invention discloses a method for constructing a large-area three-dimensional geological visualization model. The method comprises the following steps: firstly, arranging geological exploration drilling data into a standardized table; a standard stratigraphic sequence of the large-area research area is established by comprehensively considering various factors; properly processing the stratified information according to a standard stratigraphic sequence, and uniformly merging the geological data; thirdly, unifying coordinate parameters, projection parameters, measuring scales and other space parameters of modeling data; the complexity of a geological interface is judged through geological understanding, and surface models of single stratums are sequentially constructed by using the drilling layering data; then, combining the surface models of the multiple single stratums into a whole three-dimensional geological surface model according to the new-old sequence and the interpenetration relation of the stratums; and finally, adding topographic data and beauty optimization to the model. The established large-area three-dimensional geologic model can truly restore the space structure of the underground stratum, so that design and construction personnel can more intuitively observe and analyze the influence of the geologic structure on a power transmission and transformation project.

Description

Technical Field

[0001] The invention belongs to the field of power grid engineering geological engineering, and in particular relates to a method for constructing a large-area three-dimensional geological visualization model. Background Art

[0002] For power transmission and transformation projects, rich geological exploration data is the key cornerstone for the smooth progress of engineering design and construction. Since the power transmission and transformation lines are long and complex, and may cross many different geological structure areas, the cost of surveying along the lines is high. Over the years, State Grid Corporation has accumulated a large amount of multi-source geological exploration data from historical projects. The massive information contained in these data needs to be deeply mined to serve future projects and achieve cost savings.

[0003] With digital technology as the core, constructing a three-dimensional geological visualization model of a large area can not only provide strong technical support for the construction of power transmission and transformation projects, but also play an important supporting role in key links such as site selection and line selection, stability analysis, foundation scheme design, and mechanized construction plan formulation.

[0004] In the site selection and line selection stage of power transmission and transformation projects, the 3D geological visualization model of a large area can clearly display information such as topography, geological structure, and stratum lithology, helping the design unit to accurately determine the impact of geological conditions on power transmission and transformation lines, thereby selecting the best construction site and line direction. This greatly reduces the uncertainty and risk in traditional site selection and line selection methods, and improves the accuracy and efficiency of engineering construction.

[0005] In addition, during the foundation design stage, the three-dimensional geological visualization model of a large area can comprehensively consider geological conditions, engineering requirements, economic factors and other factors, provide data support for designers to select the best foundation design plan, and ensure the stability and safety of the engineering foundation. Summary of the invention

[0006] In view of the existing deficiencies, the present invention provides a method for constructing a three-dimensional geological visualization model of a large area, studies the construction method of a three-dimensional geological visualization model of a large area, and provides strong technical support for the construction of power transmission and transformation projects.

[0007] To achieve the above object, the present invention adopts the following technical solution: A method for constructing a large-area three-dimensional geological visualization model comprises the following steps: Step 1: Determine the large regional scope of 3D geological modeling, comprehensively consider the geological age, geological origin, sedimentary rhythm, rock and soil type, engineering characteristics, thickness and continuity of the foundation soil, the degree of influence on foundation design and construction, and geological factors, and establish a standard stratigraphic sequence; Step 2: Organize the collected geological information into a readable standardized form; the geological information includes the number, location, rock and soil properties, geological layer depth and groundwater level of the geological borehole; Step 3: unifying and merging the geological stratification information of different geological drilling data within the large area according to the standard stratigraphic sequence; Step 4: Extract the geological data required for modeling from the geological data such as drilling holes, and unify the spatial parameters of the modeling data. The spatial parameters include coordinate parameters, projection parameters and scale. The coordinate parameters and projection parameters adopt the pseudo-Mercator projection coordinate system. Step 5: Extract the bottom interface stratification points of the modeled strata from the standardized table of drilling data. These points represent the change trend of the bottom interface and form discrete points in space. According to the construction range of the strata interface, the size of the triangulated network is uniformly set. The bottom interface process surface of the strata is automatically constructed using these discrete points to generate a preliminary strata interface structure model. Step 6: Using the spatial discrete points of the bottom interface as control points and the contour line of the process surface as the constraint range, the discrete smooth interpolation method is used to adjust the process surface to ensure that the generated surface can pass through all control points and the stratum interface strictly follows the original drilling layering information; Step 7: Check whether the generated stratum bottom interface exceeds the stratum top interface; if so, according to the actual geological conditions, use the method of fine-tuning the triangulation or cutting out the out-of-range to make corrections, and finally obtain the accurate target stratum bottom interface; Step 8: Smooth the digital elevation model data to remove local spikes and noise in the data to ensure the continuity and smoothness of the surface terrain; next, overlay the digital orthophoto on the smoothed digital elevation model to form a surface topography with undulating changes.

[0008] The large area mentioned above refers to the administrative area at the county level and above or the engineering geological zone divided according to geological factors such as topography, geological structure, etc.

[0009] In step 4, the stratigraphic thickness data were expanded by 10 to 1000 times according to the size of the geomorphic unit and the degree of elevation fluctuation, and an offset of 10,000 m was uniformly added between the stratigraphic planes to separate the stratigraphic planes from each other.

[0010] The positive beneficial effects of the present invention are: The present invention provides a method for constructing a large-area three-dimensional geological visualization model, studies the construction method of a large-area three-dimensional geological visualization model, firstly organizes the geological exploration drilling data into a standardized table; comprehensively considers the geological age, geological genesis, rock and soil type, engineering characteristics and other factors of the foundation soil to establish a standard stratigraphic sequence for the large-area study area; according to the standard stratigraphic sequence, the layering information is properly processed and the geological data is unified and merged; then, the coordinate parameters, projection parameters, scale and other spatial parameters of the modeling data are unified; the complexity of the geological interface is judged through geological knowledge, and the surface model of a single stratum is constructed in sequence using these drilling layering data; then, according to the old and new order of the strata and the interlaced relationship, the surface models of multiple single strata are combined into the entire three-dimensional geological surface model; finally, the model is added with terrain data and aesthetic optimization. The established large-area three-dimensional geological model can truly restore the spatial structure of the underground strata, so that the design and construction personnel can more intuitively observe and analyze the impact of the geological structure on the power transmission and transformation engineering project. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a display effect diagram of the bottom interface of the stratum during the modeling process of the present invention; Figure 2 It is a display effect diagram of the stratigraphic model of the modeling process of the present invention; Figure 3 The complete model display effect diagram of the modeling process of the present invention; DETAILED DESCRIPTION

[0012] The present invention is further described below in conjunction with some specific embodiments.

[0013] A method for constructing a large-area three-dimensional geological visualization model comprises the following steps: Step 1: Determine the large regional scope of 3D geological modeling, comprehensively consider the geological age, geological origin, sedimentary rhythm, rock and soil type, engineering characteristics, thickness and continuity of the foundation soil, the degree of influence on the foundation design and construction, and geological factors, and establish a standard stratigraphic sequence; The large area mentioned above refers to the administrative area at the county level and above or the engineering geological zone divided according to geological factors such as topography, geological structure, etc.

[0014] Step 2: Organize the collected geological information such as the number, location, rock and soil properties, geological layer depth, groundwater level, etc. into a readable standardized table; Step 3: According to the standard stratigraphic sequence, the geological stratification information of different geological drilling data in the large area is appropriately unified and merged.

[0015] Step 4: Extract the geological data required for modeling from geological data such as boreholes, unify the coordinate parameters, projection parameters, scale and other spatial parameters of the modeling data, and ensure the accuracy and standardization of the data. The coordinate parameters and projection parameters use the Pseudo Mercator projection coordinate system. In a large area, the magnitude of the X and Y coordinate spans of the boreholes is much larger than the drilling depth Z, which will cause the vertical undulation characteristics of the stratigraphic interface to be completely ignored when using the original data for modeling. When processing the data, we enlarged the stratigraphic thickness data by 10 to 1000 times according to factors such as the size of the geomorphic unit and the degree of elevation undulation, and uniformly added a 10,000 m offset between the strata to separate the stratigraphic planes from each other.

[0016] Step 5: Extract the bottom interface stratification points of the modeled strata from the standardized table of drilling data. These points represent the change trend of the bottom interface and form discrete points in space. According to the construction range of the strata interface, the size of the triangulated network is uniformly set, and the bottom interface process surface of the strata is automatically constructed using these discrete points to generate a preliminary strata interface structure model.

[0017] Step 6: Using the spatial discrete points of the bottom interface as control points and the contour line of the process surface as the constraint range, the discrete smooth interpolation method is used to adjust the process surface to ensure that the generated surface can pass through all control points and that the stratigraphic interface strictly follows the original drilling stratification information.

[0018] Step 7: Check whether the generated stratum bottom interface exceeds the stratum top interface. If this happens, according to the actual geological conditions, use the method of fine-tuning the triangulation or cutting out the out-of-range to make corrections and finally obtain the accurate target stratum bottom interface.

[0019] Step 8: In order to add surface terrain information to the model, we first smoothed the digital elevation model (DEM) data to remove local spikes and noise in the data to ensure the continuity and smoothness of the surface terrain. Next, we superimposed the digital orthophoto (DOM) on the smoothed DEM to form a surface topography with undulating changes.

[0020] Example 1 A method for constructing a large-area three-dimensional geological visualization model comprises the following steps: Step 1: Determine the large regional scope of 3D geological modeling. This implementation case adopts the "Jiaozuo-Puyang engineering geological sub-area dominated by clay and sandy soil".

[0021] A standard stratigraphic sequence is established by comprehensively considering factors such as the geological age, geological origin, sedimentary rhythm, rock and soil type, engineering characteristics, thickness and continuity of the foundation soil, and the degree of influence on the design and construction of the foundation, as well as geological factors.

[0022] Step 2: Organize the collected geological information such as the number, location, rock and soil properties, geological stratification depth, groundwater level, etc. into a readable standardized table.

[0023] Step 3: According to the standard stratigraphic sequence, the geological stratification information of different geological drilling data in the large area is appropriately unified and merged.

[0024] Step 4: Extract the geological data required for modeling from the geological data such as drilling holes, unify the spatial parameters such as coordinate parameters, projection parameters, scale, etc. of the modeling data, and ensure the accuracy and standardization of the data. The coordinate parameters and projection parameters use the Pseudo Mercator projection coordinate system. According to the size of the geomorphic unit, the degree of elevation fluctuation and other factors, the stratigraphic thickness data was expanded by 100 times, and a 10,000 m offset was uniformly added between the stratigraphic planes to separate the stratigraphic planes from each other.

[0025] Step 5: Extract the bottom interface stratification points of the modeled strata from the standardized table of drilling data. These points represent the change trend of the bottom interface and form discrete points in space. According to the construction range of the strata interface, the size of the triangulated network is uniformly set, and the bottom interface process surface of the strata is automatically constructed using these discrete points to generate a preliminary strata interface structure model. Figure 1 .

[0026] Step 6: Using the spatial discrete points of the bottom interface as control points and the contour line of the process surface as the constraint range, the discrete smooth interpolation method is used to adjust the process surface to ensure that the generated surface can pass through all control points and that the stratigraphic interface strictly follows the original drilling stratification information.

[0027] Step 7: Check whether the generated stratum bottom interface exceeds the stratum top interface. If this is the case, according to the actual geological conditions, use the method of fine-tuning the triangulation or cutting out the excess range to make corrections, and finally obtain the accurate target stratum bottom interface, see Figure 2 .

[0028] Step 8: To add surface topography information to the model, we first smoothed the digital elevation model (DEM) data to remove local spikes and noise in the data to ensure the continuity and smoothness of the surface topography. Next, we superimposed the digital orthophoto (DOM) on the smoothed DEM to form a three-dimensional geological model with undulating surface topography, see Figure 3 .

Claims

1. A method for constructing a large-area three-dimensional geological visualization model, characterized in that: The steps include: Step 1: Determine the large regional scope of 3D geological modeling, comprehensively consider the geological age, geological origin, sedimentary rhythm, rock and soil type, engineering characteristics, thickness and continuity of the foundation soil, the degree of influence on foundation design and construction, and geological factors, and establish a standard stratigraphic sequence; Step 2: Organize the collected geological information into a readable standardized form; the geological information includes the number, location, rock and soil properties, geological layer depth and groundwater level of the geological borehole; Step 3: unifying and merging the geological stratification information of different geological drilling data within the large area according to the standard stratigraphic sequence; Step 4: Extract the geological data required for modeling from the geological data such as drilling holes, and unify the spatial parameters of the modeling data. The spatial parameters include coordinate parameters, projection parameters and scale. The coordinate parameters and projection parameters adopt the pseudo-Mercator projection coordinate system. Step 5: Extract the bottom interface stratification points of the modeled strata from the standardized table of drilling data. These points represent the change trend of the bottom interface and form discrete points in space. According to the construction range of the strata interface, the size of the triangulated network is uniformly set. The bottom interface process surface of the strata is automatically constructed using these discrete points to generate a preliminary strata interface structure model. Step 6: Using the spatial discrete points of the bottom interface as control points and the contour line of the process surface as the constraint range, the discrete smooth interpolation method is used to adjust the process surface to ensure that the generated surface can pass through all control points and the stratum interface strictly follows the original drilling layering information; Step 7: Check whether the generated stratum bottom interface exceeds the stratum top interface; if so, according to the actual geological conditions, use the method of fine-tuning the triangulation or cutting out the out-of-range to make corrections, and finally obtain the accurate target stratum bottom interface; Step 8: Smooth the digital elevation model data to remove local spikes and noise in the data to ensure the continuity and smoothness of the surface terrain; next, overlay the digital orthophoto on the smoothed digital elevation model to form a surface topography with undulating changes.

2. The method for constructing a large-area three-dimensional geological visualization model according to claim 1, characterized in that: The large area mentioned above refers to the administrative area at the county level and above or the engineering geological zone divided according to geological factors such as topography, geological structure, etc.

3. The method for constructing a large-area three-dimensional geological visualization model according to claim 1, characterized in that: In step 4, the stratigraphic thickness data were expanded by 10 to 1000 times according to the size of the geomorphic unit and the degree of elevation fluctuation, and an offset of 10,000 m was uniformly added between the stratigraphic planes to separate the stratigraphic planes from each other.

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