A floating semi-submersible offshore wind foundation platform and method of construction

Abstract

The application discloses a kind of offshore floating type semi-submersible structure wind power foundation platform and construction method, including column stable type platform configuration, the column stable type platform configuration is made of center column, corner column, float tank and box type diagonal brace, the center column is divided into 3 subsections along height direction, the corner column is divided into 3 subsections along height direction, the float tank is divided into 1 subsection along center line of symmetry, the length direction of the box type diagonal brace is divided into 2 subsections, the whole floating type wind power platform is divided into four big sections, i.e., center column, corner column, float tank and box type diagonal brace by the application. Then, each big section is divided into different number of subsections according to needs to meet hoisting, transfer and coating process requirements, this kind of modular construction method greatly simplifies manufacturing and assembly process, improves production efficiency, reduces cost, provides important reference for platform design and construction by providing detailed structure size and performance parameters, promotes the development of clean energy.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power generation technology, specifically to an offshore floating semi-submersible wind power foundation platform and its construction method. Background Technology

[0002] With the growing global demand for clean energy, wind power has gained increasing attention as a sustainable energy solution. Offshore wind power, as an important component of this, is attracting significant attention due to its higher wind energy extraction efficiency and lower environmental impact. However, constructing offshore wind turbine foundation platforms in deep waters has always been a technological challenge. Traditional offshore wind turbine foundation platforms mostly employ pile-type or floating structures, but with changing marine conditions, especially the increase in deep-water areas, existing technologies have limitations in coping with deep-water environments and harsh sea conditions.

[0003] Currently, some semi-submersible or semi-floating foundation platform solutions have been proposed. However, these solutions still have problems such as complex construction, high cost, and difficult manufacturing, and there is an urgent need for a more efficient, economical and environmentally friendly construction method.

[0004] Therefore, it is necessary to propose a new method and apparatus for constructing offshore wind power foundation platforms to meet the requirements of deep-water environments. This method should possess characteristics such as high structural stability, simple construction, low manufacturing cost, and strong environmental adaptability to achieve the sustainable development of the offshore wind power industry. This invention proposes an innovative method and apparatus for constructing offshore floating wind power foundation platforms to address these problems. Through improvements and innovations to existing technologies, it can effectively solve the challenges of constructing wind power foundation platforms in deep-water areas, possessing significant practical application value and broad market prospects. Summary of the Invention

[0005] The purpose of this invention is to provide a floating semi-submersible wind power foundation platform and its construction method, in order to solve the problem mentioned in the background art that traditional offshore wind power foundation platforms mostly adopt pile or floating structures, but with the changes in marine conditions, especially the increase in deep water areas, the existing technology has limitations in dealing with deep water environments and harsh sea conditions.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] As a preferred technical solution of the present invention, an offshore floating semi-submersible wind power foundation platform includes a column-stabilized platform configuration. The column-stabilized platform configuration is composed of a central column, corner columns, pontoons, and box-shaped diagonal braces. The central column is divided into 3 segments along the height direction, the corner columns are divided into 3 segments along the height direction, the pontoons are divided into 1 segment along the symmetrical center line, and the box-shaped diagonal braces are divided into 2 segments along the length direction.

[0008] As a preferred embodiment of the present invention, the center distance between the central column and the corner columns is 55m, the center distance between the corner columns is approximately 95.26m, the diameter of the central column is 6m, the diameter of the central column top cylinder is 12m, the diameter of the central column bottom float is 16m, the upper diameter of the corner columns is 13m, the diameter of the corner column cone section is 13-15m, the diameter of the corner column bottom float is 20m, the size of the pontoon connecting the central column and the corner columns is 10x5m, and the size of the box-shaped diagonal brace is 4x4m.

[0009] As a preferred embodiment of the present invention, the steel structure thickness of the pontoon and the box-shaped diagonal brace is 50-70mm.

[0010] As a preferred embodiment of the present invention, the column-stabilized platform configuration includes a displacement of approximately 21,056 tons, a draft of 23 meters, a depth of 42 meters, and a freeboard of 18 meters.

[0011] As a preferred embodiment of the present invention, the center of gravity of the central column is approximately -9.82m above the waterline.

[0012] As a preferred technical solution of the present invention, the column-stabilized platform configuration includes a construction process of modularly constructing four major sections, using a crane to weld these modules together, and conducting a watertight test.

[0013] This invention discloses a method for constructing a floating semi-submersible wind power foundation platform, comprising the following steps:

[0014] Step 1, Parts Layout: First, use steel structure detailing design software to draw a 3D drawing of the floating wind power platform foundation to obtain the precise dimensions of each part. Draw detailed drawings of each component and part as the basis for drawing the material cutting and nesting diagram and CNC programming. The center of gravity position of each component and the overall dimensions of the foundation are also included. When laying out, allowances are reserved for manufacturing and installation welding shrinkage compensation, machining allowances, etc., according to process requirements.

[0015] Step 2, Parts Cutting: When cutting parts, check the steel grade, specifications, material and other relevant information. The steel needs to undergo physical and chemical tests to determine the surface quality. If the steel is found to be uneven, corroded, or contaminated with paint or other dirt that affects the quality of the cutting, it should be corrected and cleaned before cutting. Cutting should be carried out strictly according to the process nesting diagram to ensure that the stress direction of the main components is consistent with the rolling direction of the steel. Magnetic lifting tools are used for lifting and transferring the steel to ensure the flatness of the steel plate and the parts after cutting.

[0016] Step 3: Segmented fabrication of the central column: The central column is a steel cylindrical structure with a diameter of 6 meters. The upper part of the cylinder is the top cylinder of the central column with a diameter of 12 meters, and the bottom of the cylinder has a floating cylinder with a diameter of 16 meters. A platform is arranged every 2 meters inside the cylinder, and the internal bulkhead is arranged inside the cylinder. The fabrication process uses submerged arc welding and automatic fillet welding machines to improve construction efficiency.

[0017] Step 4: Segmented Fabrication of Angle Columns: The floating foundation angle columns for offshore wind power consist of angle columns, angle column cone sections, and bottom floats. The center-to-center distance of the angle columns is approximately 95.26m, the upper diameter of the angle column is 13m, the diameter of the angle column cone section is 13-15m, and the diameter of the bottom float is 20m. Based on the weight and dimensions, and considering the actual external resource conditions, the angle column is divided into three segments: the angle column cone section cylinder, the upper part of the angle column cylinder and the angle column sealing plate, and the angle column bottom float. The angle column segments are manufactured using a vertical installation method. The ground survey lines are marked according to the design drawings, a flat jig is made on the ground, scaffolding is erected, the inner bulkhead is installed, the lower arc-shaped inner bulkhead of the column is installed, the straight inner bulkhead is installed, the straight outer bulkhead is installed, and finally the panel pieces are installed. The entire structure is then welded. After the segmented welding is completed, welding inspection is performed, and then the sections are assembled on a gantry crane.

[0018] Step 5: Segmented Fabrication of Floating Boxes and Box-Type Diagonal Braces: The floating foundation floating boxes and box-type diagonal braces for offshore wind power are fabricated in segments, consisting of 10x5m buoys, 4x4m box-type diagonal braces, and top, bottom, transverse, and web plates. The floating box and box-type diagonal brace segmented fabrication plan involves pre-assembly and fabrication. After segmented fabrication in the workshop, two gantry cranes are used to lift and place them onto the gantry crane. After sandblasting and painting, the sections are transported to the gantry crane for final assembly. Welding is performed according to the welding process requirements.

[0019] Step Six: Floating Foundation Assembly: Mark the ground layout cross lines at the assembly station and arrange the assembly jig. Before assembling the floating wind power platform, roll-on / roll-off transport jigs must be considered and placed at the designed assembly site location as part of the jig. The jig must have sufficient load-bearing capacity. Using a gantry crane, first hoist the three straight-section floating box segments, aligning them with the ground layout lines. After positioning, securely fix the segments to the jig. Then, hoist the central column in sequence, aligning it with the ground layout lines. After positioning, securely fix the segments to the jig. Weld the joint welds between the segments according to the welding process requirements. Using the gantry crane's trolleys, hoist the corner columns, the corner column cone segments, and the bottom floating cylinder segments of the corner columns in sequence. During positioning, ensure the verticality of the corner columns. After positioning, weld the joint welds between the segments according to the welding process requirements to complete the assembly.

[0020] Step 7: Roll-on / roll-off loading: The floating foundation of the offshore wind power plant, including the tooling, weighs approximately 5731t. It is loaded onto the ship using a trolley.

[0021] Step 8, Watertightness Test: Watertightness test methods include: water pressure test, air pressure test, water flushing test, kerosene leakage test, vacuum test, and immersion test. The conditions to be met before the test are as follows: Before the watertightness test, the hull and steel structure must be fully installed and welded, and have passed inspection. All compartments and outer shell plates must be thoroughly cleaned of slag, welding slag, garbage, and sewage. The areas to be inspected must be clean and dry. For components affecting watertightness, proper assembly or temporary sealing must be performed. These temporary seals should be removed after the watertightness test is completed. The sealing strips should be inspected along the contact surface using the coloring method, ensuring even pressure on the sealing surface without gaps. The integrity, appearance, and flexibility of opening and closing of the tested components must be checked. The inspected areas must be clean and dry. Painting and insulation coverings on the inspected areas should only be done after the watertightness test has passed.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] Through configuration design, manufacturing methods, construction processes, and detailed structural dimensions and performance parameters, a column-stabilized platform configuration with an equilateral triangular layout is adopted, consisting of a central column, corner columns, floating boxes, and box-shaped diagonal braces. Unlike the traditional continuous casting method, this invention adopts a segmented construction scheme, dividing the floating wind power platform into four major sections: central column, corner columns, floating boxes, and box-shaped diagonal braces. Then, the central column is divided into 3 segments along the height direction, the corner columns are divided into 3 segments along the height direction, the floating boxes are divided into 1 segment along the symmetrical center line, and the box-shaped diagonal braces are divided into 2 segments along the length direction. This segmented construction method is conducive to modular manufacturing, facilitates construction in overall assembly, meets the requirements for hoisting, transportation, and painting, and reduces manufacturing and transportation difficulties.

[0024] The construction process employs modular construction of four major sections, which are then welded and assembled using cranes to complete the overall platform assembly. After assembly, the platform undergoes a watertight test to ensure its safety and stability. The offshore floating wind turbine foundation platform construction method and device of this invention have the following advantages: the modular construction method simplifies the manufacturing process, reduces costs, minimizes environmental impact, and improves construction efficiency; the platform's optimized structural design provides excellent stability and reliability, making it suitable for deep-sea wind power projects and possessing broad application prospects and economic value.

[0025] By providing detailed structural dimensions and performance parameters, including the platform's displacement, draft, depth, freeboard, center of gravity height, initial stability, heave natural period, roll and pitch natural periods, and the amount of steel required for the foundation structure, these data provide important reference for the design and construction of the platform. Therefore, it provides an efficient, economical, and environmentally friendly floating offshore wind power foundation platform, which has a positive impact on the field of offshore wind power generation and promotes the development of clean energy. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural diagram of the central column, corner columns, pontoon, and box-shaped diagonal brace of the offshore floating semi-submersible wind power foundation platform of the present invention.

[0027] Figure 2 This is a longitudinal structural diagram of the central column, corner columns, pontoon, and box-shaped diagonal brace of the offshore floating semi-submersible wind power foundation platform of the present invention.

[0028] Figure 3 This is a top view of the offshore floating semi-submersible wind power foundation platform of the present invention.

[0029] In the diagram: 1. Floating box; 2. Box-shaped diagonal brace; 3. Top cylinder of the central column; 4. Bottom buoy of the corner column; 5. Corner column; 6. Corner column sealing plate; 7. Corner column conical section; 8. Central column; 9. Bottom buoy of the central column; 10. Upper part of the corner column cylinder. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figure 1-3 This invention provides a floating semi-submersible wind power foundation platform, including a column-stabilized platform configuration. The column-stabilized platform configuration consists of a central column 8, corner columns 5, a pontoon 1, and a box-shaped diagonal brace 2. The central column 8 is divided into 3 segments along the height direction, the corner columns 5 are divided into 3 segments along the height direction, the pontoon 1 is divided into 1 segment along the center line of symmetry, and the box-shaped diagonal brace 2 is divided into 2 segments along the length direction.

[0032] The center distance between the central column 8 and the corner columns 5 is 55m, and the center distance between the corner columns 5 is approximately 95.26m. The diameter of the central column 8 is 6m. The diameter of the central column top cylinder 3 set on the top of the central column 8 is 12m. The diameter of the central column bottom buoy 9 set on the bottom of the central column 8 is 16m. The upper diameter of the corner column 5 is 13m. The diameter of the corner column cone 7 set on the corner column 5 ranges from 13 to 15m. The diameter of the corner column bottom buoy 4 set on the bottom of the corner column 5 is 20m. The size of the buoy 1 connecting the central column 8 and the corner column 5 is 10x5m. The size of the box-shaped diagonal brace 2 is 4x4m.

[0033] The steel structure thickness of both the pontoon 1 and the box-shaped diagonal brace 2 is 50-70mm.

[0034] The column-stabilized platform configuration includes a displacement of approximately 21,056 tons, a draft of 23 meters, a depth of 42 meters, and a freeboard of 18 meters.

[0035] The center of gravity of the central column 8 is approximately -9.82m above the waterline.

[0036] The column-stabilized platform configuration involves modular construction of four main sections, which are then welded together using a crane and subjected to a watertight test.

[0037] A method for constructing an offshore floating semi-submersible wind power foundation platform includes the following steps:

[0038] Step 1, Parts Layout: First, use steel structure detailing design software to draw a 3D drawing of the floating wind power platform foundation to obtain the precise dimensions of each part. Draw detailed drawings of each component and part as the basis for drawing the material cutting and nesting diagram and CNC programming. The center of gravity position of each component and the overall dimensions of the foundation are also included. When laying out, allowances are reserved for manufacturing and installation welding shrinkage compensation, machining allowances, etc., according to process requirements.

[0039] Step 2, Parts Cutting: When cutting parts, check the steel grade, specifications, material and other relevant information. The steel needs to undergo physical and chemical tests to determine the surface quality. If the steel is found to be uneven, corroded, or contaminated with paint or other dirt that affects the quality of the cutting, it should be corrected and cleaned before cutting. Cutting should be carried out strictly according to the process nesting diagram to ensure that the stress direction of the main components is consistent with the rolling direction of the steel. Magnetic lifting tools are used for lifting and transferring the steel to ensure the flatness of the steel plate and the parts after cutting.

[0040] Step 3: Construction of the central column in 8 sections: The central column is a steel cylindrical structure with a diameter of 6 meters. The upper part of the cylinder is the top cylinder 3 of the central column with a diameter of 12 meters, and the bottom of the cylinder is a floating cylinder with a diameter of 16 meters. A platform is arranged every 2 meters inside the cylinder, and the internal bulkhead is arranged inside the cylinder. The construction process uses equipment such as submerged arc welding and automatic fillet welding machines to improve construction efficiency.

[0041] Step 4: Construction of the Angle Column 5 in Sections: The floating foundation angle column 5 for offshore wind power consists of the angle column 5, the angle column cone section 7, and the bottom buoy 4. The center distance of the angle columns 5 is approximately 95.26m, the upper diameter of the angle column 5 is 13m, the angle column cone section 7 is 13-15m in diameter, and the bottom buoy 4 has a diameter of 20m. Based on weight and dimensions, and considering actual external resource conditions, the angle column 5 is divided into 3 sections. The angle column cone section 7 is circular... The structure consists of a cylindrical upper part 10 of the corner column, a corner column sealing plate 6, and a bottom float 4 of the corner column. The corner column 5 is manufactured in sections using a vertical installation method. The ground layout line is marked according to the design drawings, a flat jig is made on the ground, scaffolding is erected, the inner bulkhead is installed, the arc-shaped inner bulkhead under the column is installed, the straight section inner bulkhead is installed, the straight section outer bulkhead is installed, and finally the panel body is installed. The whole structure is welded. After the section welding is completed, welding inspection is carried out, and then the middle assembly is carried out on the gantry.

[0042] Step 5: Segmented Fabrication of Floating Box 1 and Box-Type Diagonal Braces 2: The offshore wind power floating foundation floating box 1 and box-type diagonal braces 2 are constructed in segments, consisting of a 10x5m pontoon, 24x4m box-type diagonal braces, and top plate, bottom plate, transverse diaphragm, and web plate. The segmented fabrication scheme for floating box 1 and box-type diagonal braces 2 involves pre-assembly and fabrication. After segmented fabrication is completed in the workshop, two bridge cranes are used to lift and place them onto the gantry crane. After sandblasting and painting, the sections are transported to the gantry crane for final assembly. Welding is performed according to the welding process requirements.

[0043] Step Six: Floating Foundation Assembly: Mark the ground layout cross lines at the assembly station and arrange the assembly jig. Before assembling the floating wind power platform, roll-on / roll-off transport jigs must be considered and placed at the designed assembly site location as part of the jig. The jig must have sufficient load-bearing capacity. Using a gantry crane, first hoist the three straight-section floats, aligning them with the ground layout lines. After positioning, securely fix the sections to the jig. Then, hoist the central column in sequence, aligning it with the ground layout lines. After positioning, securely fix the sections to the jig. Weld the joint welds between the sections according to the welding process requirements. Using the gantry crane's trolleys, hoist the corner column 5, the corner column cone section 7, and the four bottom float sections of the corner column in sequence. When positioning, ensure the verticality of the corner column 5. After positioning, weld the joint welds between the sections according to the welding process requirements to complete the assembly.

[0044] Step 7: Roll-on / roll-off loading: The floating foundation of the offshore wind power plant, including the tooling, weighs approximately 5731t. It is loaded onto the ship using a trolley.

[0045] Step 8, Watertightness Test: Watertightness test methods include: water pressure test, air pressure test, water flushing test, kerosene leakage test, vacuum test, and immersion test. The conditions to be met before the test are as follows: Before the watertightness test, the hull and steel structure must be fully installed and welded, and have passed inspection. All debris, welding slag, garbage, and sewage from the compartments and outer shell plates must be thoroughly cleaned. The areas to be inspected must be clean and dry. For components that affect watertightness, they must be properly assembled or temporarily sealed. The temporary sealing components should be removed after the watertightness test is completed. The sealing strip should be inspected along the contact surface using the coloring method, and should be evenly pressed onto the sealing surface without gaps. The integrity, appearance, and flexibility of opening and closing of the tested components should be checked. The inspected areas must be clean and dry. If painting or laying insulation or other coverings is required on the inspected areas, this should be done after the watertightness test is passed.

[0046] The construction process employs modular construction of four major sections, which are then welded and assembled using cranes to complete the overall platform assembly. After assembly, the platform undergoes a watertight test to ensure its safety and stability. The offshore floating wind turbine foundation platform construction method and device of this invention have the following advantages: the modular construction method simplifies the manufacturing process, reduces costs, minimizes environmental impact, and improves construction efficiency; the platform's structural design is optimized, resulting in good stability and reliability; it is suitable for wind power projects in deep waters and has broad application prospects and economic value.

[0047] This invention employs a column-stabilized platform configuration, forming an equilateral triangular layout. It comprises components such as a central column, corner columns, pontoons, and box-shaped diagonal braces. The manufacturing method utilizes a segmented construction approach, with each part manufactured and assembled separately to meet requirements for hoisting, transport, and painting. This invention covers detailed structural dimensions and performance parameters of the platform, including data on displacement, draft, depth, freeboard, center of gravity height, initial stability, heave natural period, roll / pitch natural period, and the amount of steel used in the foundation structure. Furthermore, it includes construction processes, including modular construction and welding, and the final requirement for a watertight test to ensure the platform's safety and stability. The technical field of this invention encompasses innovations in the construction and structural design of key foundation platforms in the offshore wind power sector.

[0048] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for constructing an offshore floating semi-submersible wind power foundation platform, characterized in that, The wind power foundation platform includes a column-stabilized platform configuration, which consists of a central column (8) section, corner column (5) sections, a floating box (1) section, and a box-shaped diagonal brace (2) section. The central column (8) section is divided into 3 segments along the height direction, the corner column (5) section is divided into 3 segments along the height direction, the floating box (1) section is divided into 1 segment along the symmetrical center line, and the box-shaped diagonal brace (2) section is divided into 2 segments along the length direction. The construction method includes the following steps: Step 1, Parts Layout: First, use steel structure detailing design software to draw a 3D model of the wind power foundation platform to obtain the precise dimensions of each part. Draw detailed drawings of each component and part as the basis for drawing the material cutting and nesting diagram and CNC programming. The center of gravity of each component and the overall dimensions of the wind power foundation platform are also included. When laying out, allowances are reserved for the shrinkage compensation of manufacturing and installation welding, as well as machining allowances, according to the process requirements. Step 2, Parts Cutting: When cutting parts, check the grade, specifications, and material of the steel. The steel needs to undergo physical and chemical tests to determine the surface quality. If the steel is found to be uneven, corroded, or the paint affects the quality of the material, it should be corrected and cleaned before cutting. Cutting should be carried out strictly according to the process nesting diagram to ensure that the stress direction of the main components is consistent with the rolling direction of the steel. Magnetic lifting tools are used for lifting and transferring the steel to ensure the flatness of the steel plate and the parts after cutting. Step 3, Construction of the central column (8) section: The central column is a steel cylindrical structure with a diameter of 6 meters. The upper part of the cylinder is the top cylinder (3) of the central column with a diameter of 12 meters, and the bottom floating cylinder of the central column has a diameter of 16 meters. A platform is arranged every 2 meters inside, and the internal bulkhead is arranged inside the cylinder. The construction process adopts submerged arc automatic welding and automatic fillet welding machine to improve construction efficiency. Step 4: Construction of the Corner Column (5) Section: The corner column (5) section of the wind power foundation platform consists of the corner column (5), the corner column cone section (7), and the bottom float (4) of the corner column; the center distance of the corner columns (5) is about 95.26m, the upper diameter of the corner column (5) is 13m, the diameter of the corner column cone section (7) is 13-15m, and the diameter of the bottom float (4) of the corner column is 20m; the construction of the corner column (5) section is divided into 3 subsections based on the weight and external dimensions, combined with the actual external resource conditions. The section consists of a cone section (7) of the corner column, the upper part (10) of the corner column cylinder, the corner column sealing plate (6), and the bottom float (4) of the corner column. The corner column (5) section adopts a vertical installation and manufacturing scheme. The ground line is marked according to the design drawings, a flat jig is made on the ground, scaffolding is erected, the arc-shaped inner bulkhead under the column is installed, the inner bulkhead of the straight section is installed, the outer bulkhead of the straight section is installed, and finally the panel is installed. The whole is welded. After the section welding is completed, the welding inspection is carried out, and then the whole assembly is carried out on the gantry. Step 5, Fabrication of Floating Box (1) Section and Box-type Diagonal Bracing (2) Section: The fabrication of the floating box (1) section and box-type diagonal bracing (2) section of the wind power foundation platform consists of a 10x5m floating box, a 4x4m box-type diagonal bracing (2), and top plate, bottom plate, transverse diaphragm and web plate. The fabrication plan for the floating box (1) section and box-type diagonal bracing (2) section is as follows: pre-assembly and fabrication. After the section is fabricated in the workshop, two bridge cranes are used to lift and place it into the gantry. After sandblasting and painting, it is transported to the gantry crane for section assembly. Welding is carried out according to the requirements of the welding process. Step 6: Wind power foundation platform assembly: Mark the ground pattern cross lines at the assembly station and arrange the assembly jig tooling. Before assembling the wind power foundation platform, roll-on / roll-off transport tooling must be considered and placed at the designed location of the assembly site as part of the assembly jig. The assembly jig must have sufficient load-bearing capacity. Using a gantry crane, first hoist the three straight floating box sections, align the sections with the ground pattern lines, and then firmly fix the sections to the assembly jig. Then hoist the central column section, align the sections with the ground pattern lines, and then firmly fix the sections to the assembly jig. Weld the joint weld between the sections according to the welding process requirements. Using the gantry crane trolley, hoist the corner column (5), the corner column cone section (7), and the bottom float (4) of the corner column. When positioning, pay attention to ensure the verticality of the corner column (5). After positioning, weld the joint weld between the sections according to the welding process requirements to complete the assembly. Step 7: Roll-on / roll-off loading: The floating foundation of the offshore wind power plant, including the tooling, weighs approximately 5,731 tons. It is loaded onto the ship using a trolley. Step 8, Watertight Test: Watertight test methods include: water pressure test, air pressure test, water flushing test, kerosene leakage test, vacuum test, and immersion test. The conditions to be met before the test are as follows: Before the watertight test, the hull and steel structure must be fully installed and welded, and have passed inspection. All compartments and outer shell plates must be thoroughly cleaned of slag, welding slag, garbage, and sewage. The areas to be inspected must be clean and dry. For components affecting watertightness, proper assembly or temporary sealing must be implemented. These temporary seals should be removed after the watertight test. The sealing strips should be inspected along the contact surface using the coloring method, ensuring even application without gaps. The integrity, appearance, and flexibility of opening and closing of the tested components must be checked. The inspected areas must be clean and dry. If painting or insulation is required on the inspected areas, this should only be done after the watertight test has passed.

2. The construction method according to claim 1, characterized in that: The center distance between the central column (8) and the corner column (5) is 55m.

3. The construction method according to claim 1, characterized in that: The steel structure thickness of the pontoon (1) and the box-type diagonal brace (2) is 50-70mm.

4. The method of construction of claim 1, wherein: The column-stabilized platform configuration includes a displacement of approximately 21,056 tons, a draft of 23 meters, a depth of 42 meters, and a freeboard of 18 meters.

5. The method of construction of claim 1, wherein: The center of gravity of the central column (8) is approximately -9.82m above the waterline.

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