An assembled offshore wind turbine floating foundation structure and a method of construction thereof

Abstract

The application discloses an assembled offshore wind turbine floating foundation structure and a construction method thereof, and relates to the technical field of wind turbine foundation structures.The foundation structure comprises an upwind foundation arm assembly and a downwind foundation arm assembly; a guide shear-resistant structure is arranged at the connecting surface of the upwind foundation arm assembly and the downwind foundation arm assembly, the guide shear-resistant structure enables the upwind foundation arm assembly and the downwind foundation arm assembly to be aligned and installed and to resist shearing force, the upwind foundation arm assembly is connected with at least two downwind foundation arm assemblies through bolt assemblies to form a Y-shaped floating foundation, and a waterproof sealing structure is arranged at the connecting surface of the upwind foundation arm assembly and the downwind foundation arm assembly; the floating foundation structure of the application realizes independent manufacturing of the foundation arm assemblies, reduces the requirements on the general assembly site, reduces the construction difficulty, realizes batch manufacturing of components, and realizes on-site assembly operation in shallow water and deep water sea areas.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of offshore wind turbine floating foundation, in particular to an assembled offshore wind turbine floating foundation structure and a construction method thereof. BACKGROUND

[0002] With the development of floating wind farm sites gradually to the deep sea and the large-scale development of the unit, the installation and towing of the port side have great economic and technical challenges. In large-scale floating wind farms, it is more economical to operate the relevant processes on site as much as possible.

[0003] Traditional floating wind power projects are more constructed and installed using traditional marine engineering mode, which cannot adapt to the future scale wind farm construction and installation speed requirements. The existing wind turbine floating foundation design usually needs to be assembled on the shore and then transferred to the water, which has high requirements for the assembly site, transfer and transportation process and transportation ship, and is not conducive to the batch production requirements of wind farm construction. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide an assembled offshore wind turbine floating foundation structure and a construction method thereof, which reduces the requirements for processing sites and transportation equipment. Independent manufacturing and segmented assembly can be directly assembled and launched on the sea, which is conducive to the mass production and fast rhythm production of wind turbine foundations.

[0005] The purpose of the present application is achieved by the following technical scheme: an assembled offshore wind turbine floating foundation structure, comprising an upwind foundation arm assembly and a downwind foundation arm assembly; the upwind foundation arm assembly comprises a center connecting piece, a first transition connecting flange, a first concrete arm, a first end connecting flange and an upwind float connecting piece connected in sequence, waterproof sealing structures are arranged between the connecting surfaces of the center connecting piece, the first transition connecting flange, the first concrete arm, the first end connecting flange and the upwind float connecting piece, a guide shear-resistant structure is arranged at the connecting surface of the center connecting piece and the downwind foundation arm assembly, the upwind foundation arm assembly and the downwind foundation arm assembly can be aligned and installed and resist shear force through the guide shear-resistant structure, the upwind foundation arm assembly is connected with at least two downwind foundation arm assemblies through bolt assemblies to form a Y-shaped floating foundation, and waterproof sealing structures are arranged at the connecting surfaces of the upwind foundation arm assembly and the downwind foundation arm assembly.

[0006] Further, the first concrete arm of the upwind foundation arm assembly comprises a plurality of concrete segments; a hole for installing a prestressed tendon is arranged on the circumferential wall of each concrete segment, the concrete segments are arranged in sequence to form the first concrete arm, and the two ends of the first concrete arm are connected with the first transition connecting flange and the first end connecting flange respectively and the plurality of concrete segments are tightly connected together through the tensioning of the prestressed tendons.

[0007] Further, the center connecting piece of the upwind foundation arm assembly is bolted with the first transition connecting flange, and a guide shear-resistant structure is arranged at the connecting surface of the center connecting piece and the first transition connecting flange.

[0008] Further, the guide shear-resistant structure comprises grooves formed at the end surface of the center connecting piece and protrusions formed at the end surface of the first transition connecting flange and the downwind foundation arm assembly; the grooves and the protrusions are matched and connected with each other.

[0009] Further, the downwind foundation arm assembly comprises a second transition connecting flange, a second concrete arm, a second end connecting flange and a downwind pontoon connecting piece connected in sequence; a waterproof sealing structure is arranged between each connecting surface of the second transition connecting flange, the second concrete arm, the second end connecting flange and the downwind pontoon connecting piece of the downwind foundation arm assembly; the second concrete arm comprises a plurality of concrete segments, and a hole for mounting a prestressed tendon is arranged on the circumferential wall of each concrete segment; the concrete segments are arranged in sequence to form the second concrete arm, and the two ends of the second concrete arm are connected with the second transition connecting flange and the second end connecting flange respectively, and the plurality of concrete segments are tightly connected together through the tension of the prestressed tendons; and a protrusion matched with the center connecting piece is formed at the end surface of the second transition connecting flange.

[0010] Further, the waterproof sealing structure comprises a sink formed at the outer periphery of each connecting surface and a waterproof sealing rubber strip arranged on the sink to seal the joint between the connecting surfaces.

[0011] Further, the inner part of the upwind foundation arm assembly and the downwind foundation arm assembly is provided with a ballast pipeline, and the end part of each ballast pipeline is reserved with an interface for quick installation, so that the ballast pipelines in the inner part of the upwind foundation arm assembly and the downwind foundation arm assembly can be quickly connected and installed when the upwind foundation arm assembly and the downwind foundation arm assembly are installed.

[0012] A construction method of the above-mentioned assembled offshore wind turbine floating foundation structure, comprising the following steps:

[0013] S1, prefabricating the upwind foundation arm assembly and the downwind foundation arm assembly of the floating foundation on land, and arranging waterproof sealing stop plates at the opening end parts of the upwind foundation arm assembly and the downwind foundation arm assembly to ensure that each part forms a waterproof sealed cabin;

[0014] S2, transporting the upwind foundation arm assembly and the downwind foundation arm assembly to a preset assembly position by using a semi-submersible ship, wherein three semi-submersible ships are used to transport two same foundation arm assemblies by each semi-submersible ship;

[0015] S3, remove the waterproof sealing baffle at the abutment surface of the upwind foundation arm assembly and the downwind foundation arm assembly to be assembled, and install a plurality of positioning guide pins and waterproof sealing rubber strips;

[0016] S4, adjust the semi-submersible ships to the same height and make them stable, extend the upwind foundation arm assembly and the two downwind foundation arm assemblies to the semi-submersible ships by a certain distance through the steel rails and winches, align the positioning guide pins and the guide shear-resistant structure holes on the abutment surface, and tighten the fastening bolts of the abutment surface, then remove the positioning guide pins and pre-tighten the bolts according to the design value, and perform waterproof sealing treatment on the outside of the abutment surface according to the design requirements;

[0017] S5, complete the back connection assembly of the internal pressure ballast system pipeline and the electrical pipeline, and debug the ballast system;

[0018] S6, make the entire floating foundation submerge with the semi-submersible ships, adjust the pressure ballast system to ensure that the foundation structure is balanced to a certain draft depth, and then use a barge to tow the foundation structure away from the semi-submersible ships after the semi-submersible ships continue to submerge to a specified depth;

[0019] S7, the semi-submersible ships are floated, and steps S3 to S6 are repeated to complete the assembly of the foundation arm assemblies of another set of foundation structures in three directions on the semi-submersible ships.

[0020] Further, the step S2 comprises:

[0021] The semi-submersible ships loaded with the upwind foundation arm assemblies and the downwind foundation arm assemblies are driven to the preset assembly position, the semi-submersible ship loaded with the upwind foundation arm assembly is taken as the relative positioning reference, the semi-submersible ships loaded with the downwind port foundation arm assembly and the downwind starboard foundation arm assembly are adjusted in ship body angle to ensure that the abutment surfaces of the downwind port foundation arm assembly and the downwind starboard foundation arm assembly are parallel to the abutment surfaces at the ends of the central connecting pieces, and the semi-submersible ships are fixed by being tied to each other after being close to each other to a preset distance.

[0022] Further, the step S4 comprises:

[0023] A steel rail is laid along the longitudinal direction of each semi-submersible ship, a sliding support tool trolley is placed on the steel rail, two foundation arm assemblies are placed on the sliding support tool trolley, winches are arranged on both sides of the semi-submersible ship, each foundation arm assembly is longitudinally translated along the steel rail through the traction of the winches, and the foundation arm assemblies are fixedly connected with the ship body during transportation.

[0024] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0025] 1. The assembled floating foundation structure of offshore wind turbines of the present invention can realize the independent production of each foundation arm assembly, reduce the requirements for the final assembly site, transportation and installation ships and docks, reduce the construction difficulty and threshold, realize the batch manufacturing of components, provide a reliable idea for the batch production of wind farm construction, and realize on-site assembly operations in shallow and deep waters.

[0026] 2. The foundation structure construction method of the present invention improves the utilization rate of transport ships and speeds up the pace of assembly construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the floating foundation structure of an assembled offshore wind turbine.

[0028] Figure 2 This is a structural diagram of the upwind foundation arm assembly.

[0029] Figure 3 This is a structural diagram of the downwind foundation arm assembly.

[0030] Figure 4 Schematic diagram of the guided shear structure.

[0031] Figure 5 A top view of the assembled offshore wind turbine floating foundation structure being assembled at sea.

[0032] Figure 6 Schematic diagram of the installation structure of each foundation arm assembly on the semi-submersible vessel. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to specific embodiments.

[0034] Example 1

[0035] See also Figures 1 to 4 As shown, the assembled offshore wind turbine floating foundation structure provided in this embodiment includes an upwind foundation arm assembly 1, a leeward port side foundation arm assembly 2, and a leeward starboard side foundation arm assembly 3; the three foundation arm assemblies are arranged in a "Y" shape at a set angle, and the upwind foundation arm assembly 1 is connected to the leeward port side foundation arm assembly 2 and the leeward starboard side foundation arm assembly 3 by bolts, respectively. The bolt fasteners can adopt a combination of multiple thrust preloaders and large-size ultra-high strength bolts to obtain sufficient bearing strength at the connection nodes.

[0036] The upwind foundation arm assembly 1 comprises a center connecting piece 101, a first transition connecting flange 102, a plurality of concrete segments 103, a first end connecting flange 104, an upwind buoy connecting piece 105 and a ballast pipeline (not shown in the figure). The center connecting piece 101 is connected to the transition connecting flange 102 by bolts, and the connecting surface is provided with a guide shear-resistant structure 5 to resist the shear force and torque that may be generated on the connecting surface, thereby reducing the risk of failure of the bolt fasteners. The barrel wall of each concrete segment 103 is provided with a hole for installing a prestressed tendon 107 in the circumferential direction, and the concrete segments 103 are arranged in sequence to form a first concrete arm. The two ends of the first concrete arm are connected to the first transition connecting flange 102 and the first end connecting flange 104, respectively, and the plurality of concrete segments 103 are tightly connected by tensioning the prestressed tendons 107. The first end connecting flange 104 is connected to the upwind buoy connecting piece 105 by field welding.

[0037] The downwind port foundation arm assembly 2 has the same structure as the downwind starboard foundation arm assembly 3 and is in a mirror image relationship in the installation orientation. It comprises a second transition connecting flange 201, a plurality of concrete segments 202, a second end connecting flange 203, a downwind buoy connecting piece 204 and a ballast pipeline (not shown in the figure). The barrel wall of each concrete segment 202 is provided with a hole for installing a prestressed tendon 206 in the circumferential direction, and the concrete segments 202 are arranged in sequence to form a second concrete arm. The two ends of the second concrete arm are connected to the second transition connecting flange 201 and the second end connecting flange 203, respectively, and the plurality of concrete segments 202 are tightly connected by tensioning the prestressed tendons 206. The second end connecting flange 203 is connected to the downwind buoy connecting piece 204 by field welding.

[0038] The connecting surfaces between the components of the upwind foundation arm assembly 1, the downwind port foundation arm assembly 2 and the downwind starboard foundation arm assembly 3 are provided with waterproof sealing structures. The O-ring sealing type is used between the center connecting piece 101 and the first transition connecting flange 102 and the second transition connecting flange 201, and the sink is provided on the outer side. After the bolt is pre-tightened, the O-shaped waterproof sealing rubber strip is filled in the sink. The connecting surface is the connecting node of the root of the overall foundation structure, which bears great limit and high fatigue load. The O-ring sealing can obtain more reliable and longer service life sealing effect. The rectangular sealing ring is used between the first transition connecting flange 102 and the first end connecting flange 104 and the first concrete arm, and between the second transition connecting flange 201 and the second end connecting flange 203 and the second concrete arm end. The waterproof sealing plates 4 are assembled in all openings of the upwind foundation arm assembly 1, the downwind port foundation arm assembly 2 and the downwind starboard foundation arm assembly 3 before final assembly, to form independent waterproof sealed cabins. The center connecting piece 101 connecting flange is reserved with an O-shaped sealing ring groove, the first transition connecting flange 102 and the second transition connecting flange 201 are reserved with an O-shaped sealing ring groove between the installation end of the center connecting piece 101, the first transition connecting flange 102 and the second transition connecting flange 201 are reserved with a rectangular sealing ring groove at the installation end of the first end connecting flange 104 and the second end connecting flange 203, and the concrete arm ends are reserved with a rectangular sealing ring groove. Finally, the sealing structure of the connecting surface of each opening and the waterproof sealing plate 4 is realized.

[0039] The connecting part of the center connecting piece 101 and the first transition connecting flange 102 and the second transition connecting flange 201 is reserved with a plurality of guide shear structures 5. The guide shear structure 5 plays a certain hole alignment and guide role in the butt joint installation process of the two components, and can provide a relatively large shear and torque resistance of the connecting surface. The guide shear structure 5 is integrally formed to ensure that the guide shear structure 5 can bear a larger load. The end surface of the center connecting piece 101 is a groove of the guide shear structure 5, and the end surface of the first transition connecting flange 102 and the second transition connecting flange 201 is a protrusion. The guide shear structure 5 is appropriately distributed along the end surface of the connecting part and is staggered with each prestressed tension hole.

[0040] The structural length of the first transition connecting flange 102 and the second transition connecting flange 201 should meet the space requirement of the prestressed tension construction, and the length is about 4.8 meters. The connecting surface of the two ends of the first transition connecting flange 102 and the second transition connecting flange 201 is provided with different types of guide shear structure 5 protrusions. The cross section of each foundation arm assembly is long circular. The guide shear structure 5 protrusions at the straight section of the cross section are in the form of a long rectangular body with a wide bottom and a narrow top, and the guide shear structure 5 protrusions at the circular arc section of the cross section are in the form of a circular cylinder with a wide bottom and a narrow top.

[0041] The upwind foundation arm assembly 1, the downwind port foundation arm assembly 2 and the downwind starboard foundation arm assembly 3 have completed the construction of the pressure exhaust pipeline and the electrical pipeline (not shown in the figure) before being transported to the semi-submersible ship 6, and the end is reserved with a quick installation interface, which can be quickly connected and installed after the installation of the three foundation arm assemblies, so as to shorten the offshore construction period of the two professional construction projects.

[0042] Embodiment 2

[0043] Referring to Figures 1 to 6 As shown in the figure, the embodiment discloses a construction method of the assembled offshore wind turbine floating foundation structure according to the embodiment 1, which comprises the following steps:

[0044] S1, prefabricating the upwind foundation arm assembly 1, the downwind port foundation arm assembly 2 and the downwind starboard foundation arm assembly 3 on land, and arranging waterproof sealing plugs at the opening of the end of the upwind foundation arm assembly 1, the downwind port foundation arm assembly 2 and the downwind starboard foundation arm assembly 3, so as to ensure that each part forms a waterproof sealed cabin;

[0045] S2, the three semi-submersible ships 6 loaded with the foundation arm assemblies are driven to the preset assembly position, the semi-submersible ship 6 loaded with the upwind foundation arm assembly 1 is used as a relative positioning reference, the semi-submersible ships 6 loaded with the downwind port foundation arm assembly 2 and the downwind starboard foundation arm assembly 3 are adjusted in ship body angle, so as to ensure that the connecting surface of the downwind port foundation arm assembly 2 and the downwind starboard foundation arm assembly 3 to be connected is parallel to the connecting surface of the end of the central connecting piece 101, the semi-submersible ships 6 are moved close to each other to a preset distance and then are fixed by being tied with a cable after the fender 7 is tightly pressed, so as to be connected into a whole, and the change of the distance and the angle between the foundation arm assemblies caused by the sea wave is avoided, wherein three semi-submersible ships are used for transportation, and each semi-submersible ship transports two same foundation arm assemblies;

[0046] S3, the waterproof sealing plugs 4 at the abutting surfaces of the upwind foundation arm assembly 1, the downwind port foundation arm assembly 2 and the downwind starboard foundation arm assembly 3 to be assembled are removed, and a plurality of positioning guide pins and waterproof sealing rubber strips are installed;

[0047] S4, the semi-submersible ships 6 are adjusted to the same horizontal height and are stably transported, the upwind foundation arm assembly and the two downwind foundation arm assemblies are extended to a set distance at the tail of the semi-submersible ship through the steel rail 8 and the winch 9, the upwind foundation arm assembly 1 is extended by about 20 meters of the preset value, the downwind port and starboard foundation arm assemblies 2 and 3 are slowly extended by about 7 meters, the positioning guide pins and the guide shear structure 5 arranged on the abutting surface are aligned through the hole positions, and the abutting surface is tightly pressed, the fastening bolts and super nuts of the abutting surface are screwed, the positioning guide pins are removed, the bolts are pre-tightened according to the design value, and the abutting surface outside is treated for waterproof sealing according to the design requirements;

[0048] S5, complete the connection of the internal pressure and electrical lines of the pipe and the pipe of the ballast system, and debug the ballast system;

[0049] S6, the entire floating foundation is lowered with the semi-submersible ship 6, the floating foundation is floated, the pressure and displacement system is adjusted to ensure the balance of the foundation structure to the set draft depth, the semi-submersible ship 6 is further submerged to a depth of 8 meters, and the foundation structure is towed away from the semi-submersible ship 6 by a barge;

[0050] S7, the semi-submersible ship 6 is floated, and steps S3 to S6 are repeated to complete the assembly of the foundation arm assembly of another set of foundation structures in three directions on the semi-submersible ship 6, and the semi-submersible ship 6 is wet towed to the final assembly position.

[0051] The windward foundation arm assembly 1, the leeward left side foundation arm assembly 2 and the leeward right side foundation arm assembly 3 are prefabricated on land, the semi-submersible ship 6 of the appropriate size is selected according to the length of each assembly, the steel rail 8 is laid along the longitudinal direction of the ship body, the sliding support tool trolley 10 is placed on the steel rail 8, two foundation arm assemblies of the same type are placed on the sliding support tool trolley 10, the winch 9 is arranged on both sides, the foundation arm assembly can be longitudinally translated along the steel rail 8 through the traction of the winch 9, and the foundation arm assembly should be reliably connected and fixed with the ship body during transportation.

[0052] The above-described embodiments are only preferred embodiments of the present application, and do not limit the scope of the present application, so that any changes made according to the shape and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A method for constructing an assembled floating foundation structure for an offshore wind turbine, wherein the assembled floating foundation structure for an offshore wind turbine comprises an upwind foundation arm assembly and a downwind foundation arm assembly; the upwind foundation arm assembly comprises a central connector, a first transition connection flange, a first concrete arm, a first end connection flange and an upwind buoy connector connected in sequence, wherein a waterproof sealing structure is provided between each connection surface of the central connector, the first transition connection flange, the first concrete arm, the first end connection flange and the upwind buoy connector, and the central connector is connected to the downwind foundation arm assembly. A guide shearing structure is provided at the connection surface of the base arm assembly, through which the upwind base arm assembly and the downwind base arm assembly can be aligned and installed to resist shear force. The upwind base arm assembly is connected to at least two downwind base arm assemblies through bolt assemblies to form a Y-shaped floating foundation. At the same time, a waterproof sealing structure is provided at the connection surface of the upwind base arm assembly and the downwind base arm assembly. A guide shearing structure is provided at the connection surface of the central connecting piece of the upwind base arm assembly and the first transition connecting flange, which is characterized in that The following steps are involved: S1. Prefabricate the upwind foundation arm assembly and the downwind foundation arm assembly of the floating foundation on land, and install waterproof sealing plugs at the end openings of the upwind foundation arm assembly and the downwind foundation arm assembly to ensure that the components form a waterproof and sealed cabin; S2. Use a semi-submersible vessel to transport the upwind foundation boom assembly and the downwind foundation boom assembly to the preset assembly location respectively, wherein three semi-submersible vessels are used for transportation, and each semi-submersible vessel transports two identical foundation boom assemblies; S3. Remove the waterproof sealing plugs at the joint surfaces of the upwind base arm assembly and the downwind base arm assembly to be assembled, and install several positioning guide pins and waterproof sealing strips; S4. Adjust the loads of all semi-submersible vessels to the same horizontal height and stabilize the loading. Extend the upwind foundation boom assembly and the two downwind foundation boom assemblies to the set distance from the stern of the semi-submersible vessel using rails and winches. Align the holes using positioning guide pins and the guide shear structure provided on the docking surfaces and close the docking surfaces. Tighten the fastening bolts on the docking surfaces. After removing the positioning guide pins, pre-tighten the bolts to the designed value. Perform waterproof sealing on the outer sides of the docking surfaces according to the design requirements. S5. Complete the connection and assembly of the ballast system pipelines and electrical pipelines inside the connection surface, and debug the ballast system; S6. The entire floating foundation is launched into the water along with the semi-submersible vessel. The floating foundation is floated while the pressure-displacement system is adjusted to ensure that the foundation structure is balanced to the set draft depth. After the semi-submersible vessel continues to dive to the specified depth, the foundation structure is towed away from the semi-submersible vessel by a barge. S7. The semi-submersible vessel surfaces and repeats steps S3 to S6 to assemble another set of foundation arm assemblies in three directions of the foundation structure on the semi-submersible vessel and wet-drag them to the final assembly location.

2. The construction method of a prefabricated offshore wind turbine floating foundation structure according to claim 1, characterized in that: The step S2 comprises: Drive each semi-submersible vessel loaded with the upwind basic arm assembly and the leeward basic arm assembly to the preset assembly position, use the semi-submersible vessel loaded with the upwind basic arm assembly as the relative positioning reference, adjust the hull angle of the semi-submersible vessel loaded with the leeward port side basic arm assembly and the leeward starboard side basic arm assembly to ensure that the surfaces to be connected of the leeward port side basic arm assembly and the leeward starboard side basic arm assembly are parallel to the connecting surface of the center connecting piece end, and the semi-submersible vessels approach each other to a preset distance and then are moored to each other after the fenders are close together.

3. The construction method of a prefabricated offshore wind turbine floating foundation structure according to claim 1, characterized in that: The step S4 comprises: On each semi-submersible vessel, a full-length steel rail is laid along the longitudinal direction of the hull, and a sliding support tooling trolley is placed on the rail. Two identical basic arm assemblies are placed on the sliding support tooling trolley. The winch is installed on both sides of the semi-submersible vessel. Through the traction of the winch, each basic arm assembly can be translated longitudinally along the steel rail. During the transportation process, each basic arm assembly is connected and fixed to the semi-submersible vessel hull.

4. The construction method of a prefabricated offshore wind turbine floating foundation structure according to claim 1, characterized in that: The first concrete arm of the upwind foundation arm assembly includes multiple concrete segments; a channel for installing prestressed tendons is provided on the cylindrical wall of each concrete segment along the circumferential direction, and the concrete segments are arranged in sequence to form a first concrete arm. The two ends of the first concrete arm are respectively connected to the first transition connecting flange and the first end connecting flange, and the multiple concrete segments are tightly connected together by the tensioning of the prestressed tendons.

5. The construction method of a prefabricated offshore wind turbine floating foundation structure according to claim 1, characterized in that: The central connecting piece of the upwind base arm assembly is connected to the first transition connecting flange by bolts.

6. The construction method of a prefabricated offshore wind turbine floating foundation structure according to claim 1, characterized in that: The guide shear-resistant structure includes a groove formed at the end face of the central connecting piece and a protrusion formed at the end face of the first transition connecting flange and the downwind base arm assembly; there are a plurality of grooves and protrusions, and the two can match and dock with each other.

7. The construction method of a prefabricated offshore wind turbine floating foundation structure according to claim 1, characterized in that: The leeward base arm assembly includes a second transition connection flange, a second concrete arm, a second end connection flange and a leeward buoy connector that are connected in sequence; a waterproof sealing structure is provided between each connection surface of the second transition connection flange, the second concrete arm, the second end connection flange and the leeward buoy connector of the leeward base arm assembly, the second concrete arm includes a plurality of concrete segments, and a channel for installing prestressed tendons is provided on the cylinder wall of each concrete segment along the circumferential direction. The concrete segments are arranged in sequence to form a second concrete arm, and the two ends of the second concrete arm are respectively connected to the second transition connection flange and the second end connection flange, and the plurality of concrete segments are tightly connected together under the tensioning of the prestressed tendons; a protrusion that docks with the center connector is formed at the end face of the second transition connection flange.

8. The construction method of the assembled offshore wind turbine floating foundation structure according to claim 1 or 7, characterized in that: The waterproof sealing structure includes a sunken platform formed at the periphery of each connecting surface and a waterproof sealing strip. The waterproof sealing strip is arranged on the sunken platform and is used to seal the joints between the connecting surfaces.

9. The construction method of a prefabricated offshore wind turbine floating foundation structure according to claim 1, characterized in that: Ballast pipelines are provided inside the upwind base arm assembly and the downwind base arm assembly, and interfaces for quick installation are reserved at the ends of each ballast pipeline. When the upwind base arm assembly and the downwind base arm assembly are installed, the ballast pipelines inside them can also be quickly docked and installed.

Images