Method and system for determining a reference level for scour analysis of an offshore wind turbine foundation

Abstract

The application discloses a method and system for determining a scour analysis datum elevation of an offshore wind turbine foundation, which utilizes seabed three-dimensional point cloud data for three-dimensional modeling, analyzes shallow silt thickness through high-frequency and low-frequency sounding data, and obtains stratum distribution in combination with shallow profile data; calculates theoretical scour depth based on flow data, and reconstructs a three-dimensional grid data model; screens out suitable areas through topographic slope factor calculation, and constructs seabed datum calculation data set; calculates the average elevation of each wind turbine foundation area as the scour analysis datum elevation. The method realizes fine reconstruction of the offshore wind turbine foundation area topography, improves the accuracy and scientificity of the determination of the datum elevation, provides reliable data support for the stability evaluation and design optimization of the offshore wind turbine foundation, significantly reduces the structural safety risk caused by scour, and improves the overall safety and economic benefits of the offshore wind farm.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind turbine units, and mainly relates to a method and system for determining the elevation of a reference surface for scour analysis of an offshore wind turbine foundation. BACKGROUND

[0002] With the increasing demand for renewable energy worldwide, offshore wind power as a clean energy form has received widespread attention and rapid development. However, the stability and safety of offshore wind turbines largely depend on the stability of their foundation structures, and seabed scour is one of the important factors affecting the stability of wind turbine foundations. Seabed scour can cause soil loss around the wind turbine foundation, thereby affecting the bearing capacity of the foundation, and even possibly leading to serious consequences such as overturning of the wind turbine. Therefore, accurate analysis and monitoring of the scour of offshore wind turbine foundations is crucial to ensuring the safe operation of the wind turbine.

[0003] In existing methods for analyzing the scour of offshore wind turbine foundations, the elevation of the three-dimensional point cloud data of the seabed around the wind turbine foundation is directly used as the reference surface. Specifically, the seabed elevation within a 50m x 50m range is averaged to obtain the reference surface elevation for that area. However, this method has some obvious shortcomings. First, the seabed elevation average during each monitoring period may not be consistent, resulting in relative results for each scour analysis, which cannot be effectively compared with the results of previous analyses. This inconsistency is particularly evident in areas with severe scour, often leading to inconsistencies in the reference surface, which in turn causes contradictions in the scour analysis data, making it difficult to accurately reflect the actual scour situation.

[0004] In addition, existing methods do not fully consider the influence of factors such as seabed flow characteristics and terrain slope on the scour process, limiting the scientificity and continuity of the scour analysis. In particular, in complex seabed topography and variable current conditions, directly using the average elevation as the reference surface often cannot accurately reflect the actual scour situation, thereby affecting the accuracy and reliability of the scour analysis.

[0005] Therefore, in order to solve the shortcomings of existing methods in the scour analysis of offshore wind turbine foundations, a method for determining the elevation of a reference surface is urgently needed. SUMMARY

[0006] To solve the above-mentioned problems existing in the prior art, the present application provides a method and system for determining the elevation of a reference surface for scour analysis of an offshore wind turbine foundation.

[0007] The technical solution of the present application is as follows:

[0008] On the one hand, the present application provides a method for determining the elevation of a reference surface for scour analysis of an offshore wind turbine foundation, which comprises:

[0009] The seabed three-dimensional point cloud data, high-frequency sounding data, low-frequency sounding data, shallow profile data and flow data are collected by field measurement equipment;

[0010] Three-dimensional modeling is performed based on the seabed three-dimensional point cloud data to obtain original three-dimensional topographic data of the offshore wind turbine foundation area, and gridding processing is performed on the original three-dimensional topographic data to obtain an original three-dimensional grid data model;

[0011] The thickness of the shallow silt is calculated based on the high-frequency sounding data and the low-frequency sounding data;

[0012] Stratum distribution data including the depth and thickness of different strata are obtained based on the shallow profile data, and the thickness of the silt layer of each wind turbine foundation area is determined according to the stratum distribution data and the stratum distribution data of the wind turbine foundation in the construction drawing of the wind turbine foundation;

[0013] The theoretical scour depth of each wind turbine foundation area is calculated based on the flow data by using a semi-analytical balance scour formula;

[0014] The original three-dimensional grid data model is reconstructed using the thickness of the shallow silt, the thickness of the silt layer of each wind turbine foundation area and the theoretical scour depth of each wind turbine foundation area to obtain a reconstructed three-dimensional grid data model;

[0015] The topographic slope of each subarea is calculated based on the reconstructed three-dimensional grid data model to obtain a topographic slope factor, and a seabed base surface calculation dataset is constructed;

[0016] The reference surface elevation of the wind turbine foundation scour analysis is calculated based on the seabed base surface calculation dataset.

[0017] As a preferred embodiment of the present application, the model spacing of the original three-dimensional grid data model is 0.5 m, and each grid coordinate is represented as (x, y, h).

[0018] As a preferred embodiment of the present application, the thickness of the shallow silt calculated based on the high-frequency sounding data and the low-frequency sounding data is specifically:

[0019] The high-frequency sounding data and the low-frequency sounding data are converted into elevations by water depth to obtain high-frequency elevation data H1 and low-frequency elevation data H2, and the thickness H of the shallow silt is calculated based on the high-frequency elevation data H1 and the low-frequency elevation data H2. a , which is expressed by a formula as follows:

[0020] H a = H1-H2.

[0021] As a preferred embodiment of the present application, the thickness of the silt layer of each wind turbine foundation area is specifically determined as follows:

[0022] Comparing the stratum distribution data and the wind turbine foundation stratum distribution data, if the actual silt layer thickness is consistent with the silt layer thickness in the construction drawing, the silt layer thickness in the wind turbine foundation stratum distribution data is the silt layer thickness; otherwise, the silt layer thickness in the stratum distribution data is taken as the silt layer thickness.

[0023] As a preferred embodiment of the present application, the water flow data includes the critical velocity at the average water depth and the water flow velocity; the theoretical scour depth of each wind turbine foundation area is calculated based on the water flow data by using the semi-analytical equilibrium scour formula, and specifically, the scour depth under the action of the water flow alone S is calculated based on the water flow data and the semi-analytical equilibrium scour formula. c , S c As the theoretical scour depth of each wind turbine foundation area H c , wherein:

[0024] The semi-analytical equilibrium scour formula is specifically:

[0025]

[0026] In the formula, V c is the critical velocity at the average water depth, V is the water flow velocity, and D is the equivalent diameter of the wind turbine foundation.

[0027] As a preferred embodiment of the present application, the specific steps for obtaining the reconstructed three-dimensional grid data model are as follows:

[0028] Based on the thickness of the shallow silt, the silt layer thickness of each wind turbine foundation area, and the theoretical scour depth of each wind turbine foundation area, the elevation H in the grid coordinates is calculated, which is expressed by the formula as follows:

[0029] H=h-max(H a ,H b ,H c );

[0030] In the formula, H b is the silt layer thickness.

[0031] Based on the grid elevation H and the original three-dimensional terrain data, a reconstructed three-dimensional grid data model is obtained, and the reconstructed three-dimensional grid data model is partitioned according to a 1*1m grid.

[0032] As a preferred embodiment of the present application, terrain slope calculation is performed based on the reconstructed three-dimensional grid data model, which is expressed by the formula as follows:

[0033]

[0034] In the formula, △h is the maximum height difference of the current partition, d is the average side length of the current partition, and Ds is the slope percentage.

[0035] The terrain slope factor P is valued based on the slope percentage, which is expressed in a formula as follows:

[0036]

[0037] The terrain slope factor of each grid partition in the reconstructed three-dimensional grid data model is valued, and the grid partition with a terrain slope factor less than or equal to 0.6 is included in the seabed base surface calculation dataset.

[0038] As a preferred embodiment of the present application, the reference surface elevation of the wind turbine foundation scour analysis is calculated based on the seabed base surface calculation dataset, and is specifically:

[0039] The seabed base surface calculation dataset corresponding to each wind turbine is obtained, and the average value of the seabed base surface calculation dataset is calculated, which is taken as the reference surface elevation of the foundation scour analysis of the corresponding wind turbine.

[0040] On the other hand, the present application also provides a seabed base surface calculation dataset for offshore wind turbine foundation scour analysis, which comprises a data acquisition module, a data preprocessing module, a shallow silt thickness calculation module, a sediment layer thickness calculation module, a theoretical scour depth calculation module, a three-dimensional grid data model reconstruction module, a terrain slope calculation module, and a reference surface elevation calculation module, wherein:

[0041] The data acquisition module is used to acquire seabed three-dimensional point cloud data, high-frequency sounding data, low-frequency sounding data, shallow profile data, and flow data through field measurement equipment;

[0042] The data preprocessing module is used to perform three-dimensional modeling based on the seabed three-dimensional point cloud data to obtain original three-dimensional terrain data of the offshore wind turbine foundation area, and perform grid processing on the original three-dimensional terrain data to obtain an original three-dimensional grid data model;

[0043] The shallow silt thickness calculation module is used to calculate the thickness of the shallow silt based on the high-frequency sounding data and the low-frequency sounding data;

[0044] The sediment layer thickness calculation module is used to obtain stratum distribution data including the depth and thickness of different strata based on the shallow profile data, and determine the sediment layer thickness of each wind turbine foundation area according to the stratum distribution data and the wind turbine foundation stratum distribution data in the wind turbine foundation construction drawing;

[0045] The theoretical scour depth calculation module is used to calculate the theoretical scour depth of each wind turbine foundation area based on the flow data using a semi-analytical balance scour formula;

[0046] The reconstructed three-dimensional grid data model module is configured to reconstruct the original three-dimensional grid data model by using the thickness of the shallow silt, the thickness of the silt layer of each fan foundation area, and the theoretical scouring depth of each fan foundation area, and obtain a reconstructed three-dimensional grid data model.

[0047] The terrain slope calculation module is configured to calculate the terrain slope of each subarea based on the reconstructed three-dimensional grid data model, obtain a terrain slope factor of each subarea, and construct a seabed base surface calculation dataset.

[0048] The datum elevation calculation module is configured to calculate the datum elevation for fan foundation scouring analysis based on the seabed base surface calculation dataset.

[0049] In another aspect, the present application also provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for determining the datum elevation for fan foundation scouring analysis according to any one of the embodiments of the present application when executing the program.

[0050] Compared with the prior art, the present application has the following beneficial effects:

[0051] The present application provides a method and system for determining the datum elevation for fan foundation scouring analysis, which reconstructs the topography of the fan foundation area in detail by fusing multi-source data (such as seabed three-dimensional point cloud, high-frequency and low-frequency sounding data, shallow profile data, and flow data), combining three-dimensional modeling, gridding processing, stratum distribution analysis, and calculation of the theoretical scouring depth; based on the reconstructed three-dimensional grid data model, the seabed base surface calculation dataset suitable for scouring analysis is constructed by screening the terrain slope factor, and the datum elevation for fan foundation scouring analysis is finally calculated accurately, thereby improving the accuracy and scientificity of the determination of the datum elevation, providing reliable data support for the stability evaluation and design optimization of the fan foundation, significantly reducing the structural safety risk caused by scouring, and improving the overall safety of the offshore wind farm. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 is the method flowchart of the embodiments of the present application. DETAILED DESCRIPTION

[0053] The specific embodiments of the present application are described below to facilitate the understanding of the present application by those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments, and it is obvious to those skilled in the art that various changes are within the spirit and scope of the present application as defined in the appended claims, and all applications utilizing the concept of the present application are within the scope of protection.

[0054] The application provides the following technical solutions: a method and system for determining the elevation of a scour analysis datum plane of an offshore wind turbine foundation.

[0055] Embodiment 1:

[0056] The embodiment provides a method for determining the elevation of a scour analysis datum plane of an offshore wind turbine foundation, the method comprising:

[0057] S1, collecting seabed three-dimensional point cloud data, high-frequency sounding data, low-frequency sounding data, shallow profile data and flow data by using field measurement equipment;

[0058] Further, in the embodiment:

[0059] S11, collecting seabed three-dimensional point cloud data by using a multi-beam sonar system, the multi-beam sonar system emits multiple sound beams to the seabed, receives echo signals, calculates the sound round trip time, and thus obtains the height information of the seabed; by multiple scanning, high-precision seabed three-dimensional point cloud data is generated;

[0060] S12, collecting high-frequency sounding data and low-frequency sounding data by using a single-beam sonar, the single-beam sonar emits a single sound beam to the seabed, receives echo signals, calculates the sound round trip time, and thus obtains the seabed depth, wherein the high-frequency sounding data uses sound waves with higher frequency and higher resolution but weaker penetration; the low-frequency sounding data uses sound waves with lower frequency and stronger penetration but lower resolution;

[0061] S13, obtaining shallow profile data by using a shallow sub-bottom profiler, the shallow sub-bottom profiler emits low-frequency sound waves, penetrates the seabed surface, identifies the boundaries of different strata, and obtains stratum distribution data including the depth and thickness of different strata based on the identification results;

[0062] S14, collecting flow data by using an acoustic Doppler current profiler, the acoustic Doppler current profiler emits sound waves into the water body, receives echo signals, and calculates the flow velocity by using the Doppler effect; the acoustic Doppler current profiler can simultaneously measure the flow velocity and direction in water layers at different depths;

[0063] S2, performing three-dimensional modeling based on the seabed three-dimensional point cloud data to obtain original three-dimensional topographic data of the offshore wind turbine foundation area, and performing grid processing on the original three-dimensional topographic data to obtain an original three-dimensional grid data model;

[0064] Further, the model interval of the original three-dimensional grid data model is 0.5 m, and each grid coordinate is represented as (x, y, h);

[0065] S3, calculating and obtaining the thickness of shallow silt based on the high-frequency sounding data and the low-frequency sounding data;

[0066] Specifically, the high-frequency sounding data and the low-frequency sounding data are converted into elevations by water depth to obtain high-frequency elevation data H1 and low-frequency elevation data H2, which are consistent in plane position; the thickness H of the shallow silt is calculated based on the high-frequency elevation data H1 and the low-frequency elevation data H2 a , which is expressed by a formula as follows:

[0067] H a = H1-H2

[0068] S4, stratigraphic distribution data including depths and thicknesses of different strata are obtained based on the shallow profile data, and the thickness of the silt layer of each wind turbine foundation area is determined according to the stratigraphic distribution data and wind turbine foundation stratigraphic distribution data in the wind turbine foundation construction drawing;

[0069] The wind turbine foundation stratigraphic distribution data in the wind turbine foundation construction drawing are obtained during the design period, the stratigraphic distribution data and the wind turbine foundation stratigraphic distribution data are compared, if the actual thickness of the silt layer is consistent with the thickness of the silt layer in the construction drawing, the thickness of the silt layer in the wind turbine foundation stratigraphic distribution data is the thickness of the silt layer; otherwise, the thickness of the silt layer in the stratigraphic distribution data is taken as the thickness of the silt layer;

[0070] S5, the theoretical scour depth of each wind turbine foundation area is calculated based on the flow data by using a semi-analytical balance scour formula;

[0071] The flow data include the critical velocity at the average water depth and the flow velocity;

[0072] The theoretical scour depth of each wind turbine foundation area calculated based on the flow data by using the semi-analytical balance scour formula is specifically the scour depth S under the action of the flow alone, which is calculated based on the flow data and the semi-analytical balance scour formula c , and S c is taken as the theoretical scour depth H c of each wind turbine foundation area.

[0073] The semi-analytical balance scour formula is specifically as follows:

[0074]

[0075] In the formula, V c is the critical velocity at the average water depth, V is the flow velocity, and D is the equivalent diameter of the wind turbine foundation;

[0076] Further, the step of obtaining the critical velocity V c at the average water depth includes:

[0077] The median particle size d 50 of the silt (unit: m) is determined by field sampling or historical data;

[0078] Based on the median particle size d of sediment 50 Calculate the critical shear stress τ c Expressed as a formula:

[0079]

[0080] In the formula, ρ represents the density of water, taken as 1000 kg / m³. 3 g represents the acceleration due to gravity, taken as 9.81 m / s². 2 ;ρ s The density of the sediment is taken as 2650 kg / m³. 3 τ0 represents the critical Shields parameter, which is set to 0.047.

[0081] Through the critical shear stress τ c Calculate the critical velocity V at average water depth c Expressed as a formula:

[0082]

[0083] In the formula, C f Here, n is the friction coefficient, and n is the Manning roughness coefficient. Depending on the type of substrate, the Manning roughness coefficient has corresponding empirical values. For example, n ∈ [0.012, 0.015] for cement channels, n ∈ [0.022, 0.025] for stone channels, n ∈ [0.025, 0.030] for clay channels, n ∈ [0.012, 0.015] for concrete pipes, and n ∈ [0.025, 0.040] for silty riverbeds.

[0084] To improve accuracy, the Manning roughness coefficient is derived by inversely calculating the flow velocity, water depth, and bottom slope data collected on-site using field measurement equipment. The formula is as follows:

[0085]

[0086] In the formula, V avg R is the average flow velocity, R is the hydraulic radius, and S is the bottom slope;

[0087] The hydraulic radius R is calculated by combining the water depth with the geometric parameters of the channel. The corresponding relationship is calculated based on the cross-sectional shape of the channel, which will not be elaborated here.

[0088] S6. The original three-dimensional grid data model is reconstructed by using the thickness of the shallow silt, the thickness of the mud and sand layer in each wind turbine foundation area, and the theoretical scour depth of each wind turbine foundation area to obtain the reconstructed three-dimensional grid data model.

[0089] The elevation H in the grid coordinates is calculated based on the thickness of the shallow silt, the thickness of the silt layer in each fan foundation area, and the theoretical scouring depth of each fan foundation area, and is expressed by a formula as follows:

[0090] H = h - max(H a ,H b ,H c );

[0091] In the formula, H b is the thickness of the silt layer;

[0092] A reconstructed three-dimensional grid data model is obtained based on the grid elevation H and the original three-dimensional terrain data, the reconstructed three-dimensional grid data model removes the elevation influence caused by the dynamic of the seabed floating silt and the surface silt, and ensures that the seabed within a certain range of the fan foundation is not affected by the short-time dynamic of the sea current;

[0093] Further, in the original three-dimensional grid data model, the distribution of the data points corresponding to the seabed three-dimensional point cloud data collected by the multi-beam sonar system is dense enough to accurately capture the changes and details of the seabed terrain, meeting the demand for high precision, and the original three-dimensional grid data model adopts a distance requirement of 0.5 units; the reconstructed three-dimensional grid data model combines multiple data sources to obtain a datum plane, and after correction and optimization of the datum plane, the model can still accurately reflect the actual seabed terrain characteristics under a larger scale of grid division, and the grid spacing is increased from 0.5 units to 1 unit, the number of grids is significantly reduced, and the data volume and computational complexity are reduced, which not only improves the calculation rate, but also reduces the burden of storage and processing, therefore, the reconstructed three-dimensional grid data model is divided into a grid with a size of 1*1 m;

[0094] S7, terrain slope calculation is performed based on the reconstructed three-dimensional grid data model to obtain a terrain slope factor of each partition, and a seabed datum plane calculation dataset is constructed, wherein the terrain slope factor is a dimensionless parameter, usually between 0 and 1, used to quantify the influence of the terrain slope on a certain process, the greater the terrain slope factor, the greater the influence of the slope on the process; the smaller the terrain slope factor, the smaller the influence of the slope on the process;

[0095] S71, terrain slope calculation is performed based on the reconstructed three-dimensional grid data model, and is expressed by a formula as follows:

[0096]

[0097] In the formula, △h is the maximum height difference of the current partition, d is the average side length of the current partition, and Ds is the slope percentage;

[0098] S72, the terrain slope factor P is valued based on the slope percentage, and is expressed by a formula as follows:

[0099]

[0100] S73, the topographic slope factor of each grid partition in the reconstructed three-dimensional grid data model is valued, and the grid partition with a topographic slope factor less than or equal to 0.6 is included in the seabed base surface calculation dataset according to the average elevation, that is, when S is 1.0, the average elevation of the points in the grid partition is not included in the seabed base surface calculation dataset;

[0101] S8, the reference surface elevation of the wind turbine foundation scour analysis is calculated based on the seabed base surface calculation dataset;

[0102] Specifically, the seabed base surface calculation dataset corresponding to each wind turbine is obtained, and the average value of the seabed base surface calculation dataset is calculated as the reference surface elevation of the wind turbine foundation scour analysis.

[0103] Embodiment 2:

[0104] The embodiment provides a seabed base surface calculation dataset corresponding to each wind turbine is obtained, and the average value of the seabed base surface calculation dataset is calculated as the reference surface elevation of the wind turbine foundation scour analysis.

[0105] The data acquisition module is used to acquire seabed three-dimensional point cloud data, high-frequency sounding data, low-frequency sounding data, shallow profile data and flow data through field measurement equipment;

[0106] The data preprocessing module is used to perform three-dimensional modeling based on the seabed three-dimensional point cloud data to obtain original three-dimensional topographic data of the offshore wind turbine foundation area, and perform grid processing on the original three-dimensional topographic data to obtain an original three-dimensional grid data model;

[0107] The shallow silt thickness calculation module is used to calculate the thickness of the shallow silt based on the high-frequency sounding data and the low-frequency sounding data;

[0108] The silt layer thickness calculation module is used to obtain stratum distribution data including the depth and thickness of different strata based on the shallow profile data, and determine the silt layer thickness of each wind turbine foundation area according to the stratum distribution data and the wind turbine foundation stratum distribution data in the wind turbine foundation construction drawing;

[0109] The theoretical scour depth calculation module is used to calculate the theoretical scour depth of each wind turbine foundation area based on the flow data using a semi-analytical balance scour formula;

[0110] The reconstructed three-dimensional grid data model module is configured to reconstruct the original three-dimensional grid data model by using the thickness of the shallow silt, the thickness of the silt layer of each fan foundation area, and the theoretical scouring depth of each fan foundation area, and obtain a reconstructed three-dimensional grid data model;

[0111] The terrain slope calculation module is configured to calculate terrain slope based on the reconstructed three-dimensional grid data model, obtain a terrain slope factor of each subarea, and construct a seabed base surface calculation dataset;

[0112] The datum surface elevation calculation module is configured to calculate a datum surface elevation for fan foundation scouring analysis based on the seabed base surface calculation dataset.

[0113] Embodiment 3

[0114] The embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the method for determining a datum surface elevation of offshore fan foundation scouring analysis according to any one of the embodiments when executing the program.

[0115] The above description is merely an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, based on the content of the specification and drawings of the present application, are also included in the patent protection scope of the present application.

Claims

1. A method of determining a scour analysis datum elevation for an offshore wind turbine foundation, characterized by, The method comprises: acquiring seabed three-dimensional point cloud data, high-frequency sounding data, low-frequency sounding data, shallow profile data and flow data through field measurement equipment; performing three-dimensional modeling based on the seabed three-dimensional point cloud data to obtain original three-dimensional topography data of a wind turbine foundation area, and performing grid processing on the original three-dimensional topography data to obtain an original three-dimensional grid data model; calculating the thickness of shallow silt based on the high-frequency sounding data and the low-frequency sounding data; obtaining stratum distribution data including the depth and thickness of different strata based on the shallow profile data, and determining the thickness of the silt layer of each wind turbine foundation area according to the stratum distribution data and wind turbine foundation stratum distribution data in a construction drawing of the wind turbine foundation; The water flow data include the critical velocity and the water flow velocity at the average water depth, and the scour depth under the action of the water flow alone is calculated based on the water flow data and a semi-analytical equilibrium scour formula , the theoretical scour depth of each fan foundation area , wherein: the semi-analytical equilibrium scour formula is specifically: ； wherein is the critical velocity at the average water depth, is the water flow velocity, is the equivalent diameter of the fan foundation; reconstructing the original three-dimensional grid data model using the thickness of the shallow silt, the thickness of the silt layer of each wind turbine foundation area and the theoretical scour depth of each wind turbine foundation area to obtain a reconstructed three-dimensional grid data model; performing terrain slope calculation based on the reconstructed three-dimensional grid data model, which is expressed by a formula as: ； wherein is the maximum height difference of the current partition, is the average side length of the current partition, is the percentage of slope; based on the slope percentage to a terrain slope factor an assignment is made, expressed in a formula as: ； assigning a terrain slope factor to each grid partition in the reconstructed three-dimensional grid data model, and including the average elevation of the grid partition with a terrain slope factor less than or equal to 0.6 into a seabed base surface calculation dataset; calculating the reference surface elevation for wind turbine foundation scour analysis based on the seabed base surface calculation dataset.

2. A scour analysis benchmark elevation determination method for offshore windmill foundations according to claim 1, characterized in that, The model interval of the original three-dimensional grid data model is 0.5 m, and each grid coordinate is represented as .

3. A scour analysis datum elevation determination method for offshore windmill foundations according to claim 2, characterized in that, The specific steps for calculating the thickness of the shallow silt based on the high-frequency sounding data and the low-frequency sounding data are as follows: The high-frequency sounding data and the low-frequency sounding data are converted into elevations through water depth to obtain high-frequency elevation data and low-frequency elevation data Based on the high-frequency elevation data and the low-frequency elevation data The thickness of the shallow silt is calculated which is expressed by a formula as 。 4. A scour analysis datum elevation determination method for offshore windmill foundations according to claim 3, characterized in that, The specific steps for determining the thickness of the silt layer of each wind turbine foundation area are as follows: comparing the stratum distribution data and the wind turbine foundation stratum distribution data, if the actual thickness of the silt layer is consistent with the thickness of the silt layer in the construction drawing, the thickness of the silt layer in the wind turbine foundation stratum distribution data is the thickness of the silt layer; otherwise, the thickness of the silt layer in the stratum distribution data is taken as the thickness of the silt layer.

5. A scour analysis datum elevation determination method for offshore windmill foundations according to claim 4, characterized in that, The specific steps for obtaining the reconstructed three-dimensional grid data model are as follows: Based on the thickness of the shallow silt, the thickness of the silt layer for each fan foundation area, and the theoretical scour depth for each fan foundation area, the elevation in grid coordinates is calculated In formula expression: ； In the formula, is the thickness of the sediment layer; Based on grid elevation and the original three-dimensional terrain data to obtain a reconstructed three-dimensional grid data model, which is partitioned by 1*1m grid.

6. A scour analysis benchmark elevation determination method for offshore windmill foundations according to claim 5, characterized in that, The specific steps for calculating the reference surface elevation for wind turbine foundation scour analysis based on the seabed base surface calculation dataset are as follows: obtaining the seabed base surface calculation dataset corresponding to each wind turbine, and calculating the average value of the seabed base surface calculation dataset, which is taken as the reference surface elevation for the foundation scour analysis of the corresponding wind turbine.

7. An offshore windmill foundation scour analysis datum elevation determination system, characterized by, The system comprises a data acquisition module, a data preprocessing module, a shallow silt thickness calculation module, a silt layer thickness calculation module, a theoretical scour depth calculation module, a reconstructed three-dimensional grid data model module, a terrain slope calculation module and a reference surface elevation calculation module, wherein: the data acquisition module is configured to acquire seabed three-dimensional point cloud data, high-frequency sounding data, low-frequency sounding data, shallow profile data and flow data through field measurement equipment; the data preprocessing module is configured to perform three-dimensional modeling based on the seabed three-dimensional point cloud data to obtain original three-dimensional topography data of a wind turbine foundation area, and perform grid processing on the original three-dimensional topography data to obtain an original three-dimensional grid data model; the shallow silt thickness calculation module is configured to calculate the thickness of shallow silt based on the high-frequency sounding data and the low-frequency sounding data; the silt layer thickness calculation module is configured to determine the thickness of the silt layer of each wind turbine foundation area; The silt layer thickness calculation module is configured to obtain stratum distribution data including the depth and thickness of different strata based on the shallow profile data, and determine the silt layer thickness of each wind turbine foundation area according to the stratum distribution data and the stratum distribution data of the wind turbine foundation in the wind turbine foundation construction drawing; The theoretical scour depth calculation module is configured to calculate the theoretical scour depth of each fan foundation area based on the flow data by using a semi-analytical equilibrium scour formula, wherein the flow data comprises a critical velocity at an average water depth and a flow velocity, and the scour depth under the action of the flow alone is calculated based on the flow data and the semi-analytical equilibrium scour formula , the semi-analytical equilibrium scour formula is specifically as follows: The theoretical scour depth of each fan foundation area is calculated based on the flow data by using the semi-analytical equilibrium scour formula , the semi-analytical equilibrium scour formula is specifically as follows: ； wherein is the critical velocity at the average water depth, is the water flow velocity, is the equivalent diameter of the fan foundation; The reconstructed three-dimensional grid data model module is configured to reconstruct the original three-dimensional grid data model by using the thickness of the shallow silt, the silt layer thickness of each wind turbine foundation area and the theoretical scour depth of each wind turbine foundation area, and obtain a reconstructed three-dimensional grid data model; The terrain slope calculation module is configured to calculate the terrain slope based on the reconstructed three-dimensional grid data model, obtain the terrain slope factor of each subarea, and construct a seabed base surface calculation dataset, specifically: The terrain slope is calculated based on the reconstructed three-dimensional grid data model, and expressed in a formula as: ； wherein is the maximum height difference of the current partition, is the average side length of the current partition, is the percentage of slope; based on the slope percentage to a terrain slope factor an assignment is made, expressed in a formula as: ； The terrain slope factor of each grid subarea in the reconstructed three-dimensional grid data model is assigned a value, and the average elevation of the grid subarea corresponding to the terrain slope factor less than or equal to 0.6 is included in the seabed base surface calculation dataset; The datum plane elevation calculation module is configured to calculate the datum plane elevation for the wind turbine foundation scour analysis based on the seabed base surface calculation dataset.

8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the method for determining the datum plane elevation for the offshore wind turbine foundation scour analysis according to any one of claims 1 to 6.

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