Multi-degree-of-freedom mooring tensioning type composite anchor and mounting method thereof

Abstract

The invention relates to a multi-degree-of-freedom mooring tensioning type composite anchor and a mounting method thereof, and the composite anchor comprises a gravity anchor assembly and a suction anchor assembly; the gravity anchor assembly is used for being connected with an upper draught fan and providing a stable gravity foundation and multi-freedom-degree rotation for the draught fan. The top of the suction anchor assembly is fixed to the bottom of the gravity anchor assembly, and the suction anchor assembly is used for penetrating into a seabed with the target depth. The defects of a single foundation type can be overcome, multi-degree-of-freedom rotation can be achieved under the load effect of the mooring line, the bearing capacity of the foundation is brought into full play, meanwhile, the torque load borne by the foundation is reduced, the rotation trend of the foundation is reduced, and the stability of the foundation is improved.

Description

Technical Field

[0001] The invention relates to the technical field of offshore wind power, and in particular to a multi-degree-of-freedom mooring tensioned composite anchor and an installation method thereof. Background Art

[0002] As a clean and renewable energy, offshore wind power is of great significance in addressing global climate change and achieving energy structure transformation. With technological progress and policy promotion, the offshore wind power industry has developed rapidly in recent years. However, the further development of offshore wind power still faces challenges in many aspects, such as wind power development technology in deep sea areas, stability of wind turbines under extreme climatic conditions such as typhoons, and cost-effectiveness issues.

[0003] In the construction of offshore wind farms, anchor foundation is one of the key technologies to ensure the stable operation of wind turbines. At present, the commonly used anchor foundation types are mainly suction anchors and gravity anchors. Suction anchors have been widely used in specific geological conditions such as soft soil due to their advantages such as simple construction, relatively low cost and small impact on the environment. Gravity anchors have better application effects in deep water areas or hard soil layers due to their simple structure and high stability.

[0004] As a traditional anchor foundation type, gravity anchors rely on their own weight and the friction between the bottom structure and the soil to provide stability. However, the large size and weight of gravity anchors lead to high transportation and installation costs, especially in deep waters. Secondly, gravity anchors have high requirements for the flatness of the seabed topography and the properties of the soil layer, and their design size is limited by the lifting capacity of the installation ship. In addition, the bearing capacity of gravity anchors under horizontal loads has certain limitations. Suction anchors are a new type of foundation that has been widely used in recent years. However, with the continuous increase in the capacity of wind turbines, the size of wind turbines has also continued to increase, which requires a larger foundation size to provide higher bearing performance, and an overly large foundation size will bring certain installation difficulties. Especially in sandy seabeds, the large end resistance may make it difficult for the suction anchor to penetrate to the target depth, resulting in installation failure. In addition, under the action of wind, waves and currents, the mooring line often causes the anchor foundation to be subjected to out-of-plane torque loads at the anchor point, causing safety hazards such as torsional instability and damage to the foundation. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a multi-degree-of-freedom mooring tensioned composite anchor and its installation method, which can make up for the shortcomings of a single foundation type, can realize multi-degree-of-freedom rotation under the action of the mooring line load, fully exert the bearing capacity of the foundation, reduce the torque load on the foundation, reduce the rotation tendency of the foundation, and increase the stability of the foundation.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The multi-degree-of-freedom mooring tensioned composite anchor described in the present invention comprises a gravity anchor assembly and a suction anchor assembly; the gravity anchor assembly is used to be connected to an upper wind turbine and provide a stable gravity foundation and multi-degree-of-freedom rotation for the wind turbine; the top of the suction anchor assembly is fixed to the bottom of the gravity anchor assembly and is used to penetrate into the seabed at a target depth.

[0008] The multi-degree-of-freedom mooring tensioned composite anchor, preferably, the gravity anchor assembly comprises: a steel trough, a reinforcement plate and a multi-directional hinged structure; the steel trough is a shell structure with openings at the top and bottom; a plurality of the reinforcement plates are arranged in the steel trough, and the two ends are respectively connected to the inner wall of the steel trough; the top of each reinforcement plate is provided with the multi-directional hinged structure, and the multi-directional hinged structure is used to connect to the wind turbine foundation and provide multi-degree-of-freedom rotation for the wind turbine; concrete blocks are cast in the steel trough, and the concrete blocks are used to provide a stable gravity foundation for the wind turbine.

[0009] The multi-degree-of-freedom mooring tensioned composite anchor, preferably, the multi-directional articulated structure includes an axial rotation device, a horizontal rotation device and a guide hole; the axial rotation device includes a base and an axial rotation axis; the center of the base is movably connected to the reinforcement plate through the axial rotation axis; the horizontal rotation device includes a connecting piece and a horizontal rotation axis, two connecting pieces are respectively fixed on the base, and connecting pieces are provided with connecting holes; both ends of the horizontal rotation axis extend into the connecting holes of the two connecting pieces, so that the horizontal rotation axis can be rotatably connected to the connecting pieces; the guide hole is fixedly arranged on the horizontal rotation axis, and is used to be connected to the upper fan through a mooring chain.

[0010] The multi-degree-of-freedom mooring tensioned composite anchor, preferably, the gravity anchor assembly further comprises lifting ears, the lifting ears are respectively arranged on the outer wall of the steel channel, and are used for lifting the composite anchor.

[0011] The multi-degree-of-freedom mooring tensioned composite anchor preferably has two lifting ears, and the lifting ears are at a set distance from the top of the steel channel.

[0012] The multi-degree-of-freedom mooring tensioned composite anchor, preferably, the suction anchor assembly comprises: a cylinder cover and a cylinder skirt; the cylinder cover is arranged at the bottom of the steel trough; the cylinder skirt is a cylindrical structure, the upper end of which is connected to the cylinder cover, and the lower end penetrates into the seabed at the target depth.

[0013] The multi-degree-of-freedom mooring tensioned composite anchor is preferably provided with drainage holes on the top of the tube skirt.

[0014] For the multi-degree-of-freedom mooring tensioned composite anchor, preferably, the outer diameter of the cross section of the tube skirt is D, and the outer diameter of the cross section of the steel channel is 1.5D-2D.

[0015] The present invention also provides a method for installing a multi-degree-of-freedom mooring tensioned composite anchor, comprising the following steps:

[0016] On the shore, concrete slurry is injected into the steel groove of the gravity anchor assembly equipped with a reinforcement plate and a multi-directional hinged structure, and the multi-directional hinged structure is exposed, and the suction anchor assembly is connected with the gravity anchor assembly. After the multi-degree-of-freedom mooring tensioned composite anchor is prefabricated as a whole, it is suspended to the transport ship by a steel cable;

[0017] The multi-degree-of-freedom mooring tension composite anchor is transported to the designated location by a transport ship, and slowly suspended to the top of the installation location by the crane of the installation ship. During the lowering process, seawater is allowed to be discharged through the drainage holes of the suction anchor assembly.

[0018] The multi-degree-of-freedom mooring tensioned composite anchor is placed on the seabed, and combined with its own weight, the suction anchor assembly is penetrated into the seabed at a set penetration speed;

[0019] When the penetration is completed, the sling is separated from the composite anchor by an underwater robot, and a suction pump is used to pump water out through the drainage hole. A pressure difference is generated inside and outside the suction anchor assembly. Under the action of the pressure difference, the multi-degree-of-freedom mooring tensioned composite anchor continues to penetrate into the seabed at the set penetration speed until the penetration is completed. The installation of the multi-degree-of-freedom mooring tensioned composite anchor is completed.

[0020] The installation method, preferably, needs to overcome the penetration resistance of the seabed to the cylinder wall structure of the suction anchor assembly;

[0021] The penetration resistance of the multi-degree-of-freedom mooring tension composite anchor during the penetration process is obtained using the static penetration test data:

[0022]

[0023] In the formula, k p k is the empirical coefficient of end resistance; f is the empirical coefficient of friction resistance; d is the penetration depth; A p A is the skirt end area of ​​the suction anchor assembly; s is the unit tube skirt side area; q c It is the cone tip resistance value measured by CPT.

[0024] The present invention adopts the above technical solution, which has the following advantages:

[0025] (1) The present invention significantly improves the bearing capacity of the anchor foundation under different seabed conditions by combining the advantages of gravity anchors and suction anchors;

[0026] (2) The design of the multi-directional hinged structure of the present invention can effectively reduce the torque load transmitted by the mooring line and reduce the disturbance of the soil caused by the foundation torsion, thereby improving the stability and reliability of the overall structure;

[0027] (3) The present invention optimizes the size and weight of the gravity anchor in design, which reduces the cost of transportation and installation compared to traditional gravity anchors, while providing horizontal load-bearing performance;

[0028] (4) The composite anchor foundation of the present invention is applicable to a variety of seabed geological conditions, including soft soil layers and hard soil layers, as well as deep and shallow water areas; the flexibility of the multi-directional hinged structure enables the anchor foundation to better adapt to changes in seabed topography, thereby increasing the scope of engineering applications in complex seabed environments;

[0029] (5) The present invention can significantly reduce the stress concentration of the anchor chain and the anchor eye by adding a multi-directional hinged structure on the top of the gravity anchor assembly, thereby reducing the fatigue damage of the structure under the action of wind, wave and current loads and improving the durability of the structure;

[0030] (6) The present invention fully considers the impact on the marine environment during the design and installation process, and the construction is simple and the interference to the seabed ecology is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:

[0032] Figure 1 It is a three-dimensional structural schematic diagram of the basic structure of the gravity anchor assembly in the present invention;

[0033] Figure 2 yes Figure 1 Schematic diagram of the main structure;

[0034] Figure 3 yes Figure 1 A schematic diagram of a top view structure;

[0035] Figure 4 It is a three-dimensional structural schematic diagram of the basic structure of the gravity anchor assembly after prefabrication of the present invention;

[0036] Figure 5 yes Figure 4 Schematic diagram of the main structure;

[0037] Figure 6 yes Figure 4 A schematic diagram of a top view structure;

[0038] Figure 7 It is a structural schematic diagram of a multi-directional hinged structure in a gravity anchor assembly of the present invention;

[0039] Figure 8 It is a structural schematic diagram of a reinforcement plate in a gravity anchor assembly of the present invention;

[0040] Fig. 9 It is a schematic diagram of the main structure of the overall structure of the present invention;

[0041] Fig.10 It is a three-dimensional structural schematic diagram of the overall structure of the present invention;

[0042] Fig.11 It is a schematic diagram of the overall structure of the present invention after prefabrication;

[0043] Fig.12 It is a schematic diagram of the grouting prefabrication stage of the installation step 1 of the present invention;

[0044] Fig.13 This is a schematic diagram of the hoisting and sinking stage of the second installation step of the present invention;

[0045] Fig.14 This is a schematic diagram of the self-weight penetration stage of the third installation step of the present invention;

[0046] Fig.15 This is a schematic diagram of the suction penetration stage of the fourth installation step of the present invention;

[0047] Fig.16 This is a schematic diagram of the installation completion of the present invention;

[0048] Fig.17 It is a schematic diagram of the present invention in service.

[0049] The reference numerals in the figures are as follows:

[0050] 1- gravity anchor assembly; 1-1- steel channel; 1-2- lifting ear; 1-3- reinforcing plate; 1-4- multi-directional hinged structure; 1-4-1- axial rotation device; 1-4-1-1- base; 1-4-1-2- axial rotation axis; 1-4-2- horizontal rotation device; 1-4-2-1- horizontal rotation axis; 1-4-2-2- connector; 1-4-2-3- connector hole; 1-4-3- cable guide hole; 1-5- concrete block 2- suction anchor assembly; 2-1- cylinder cover; 2-2- cylinder skirt, 2-3- drainage hole. DETAILED DESCRIPTION

[0051] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0052] The present invention provides a multi-degree-of-freedom mooring tensioned composite anchor, which combines a gravity anchor and a suction anchor to form a composite anchoring foundation, giving full play to the advantages of both and making up for the shortcomings of a single foundation type. Two multi-directional hinged structures are arranged on the top of the gravity anchor, which are connected to a mooring chain and can realize multi-degree-of-freedom rotation under the action of a mooring line load. While giving full play to the bearing capacity of the foundation, the torque load on the foundation is reduced, the rotation tendency of the foundation is reduced, and the stability of the foundation is increased.

[0053] like Fig. 9 , Fig.10 and Fig.11 As shown, the multi-degree-of-freedom mooring tensioned composite anchor provided by the present invention comprises a gravity anchor assembly 1 and a suction anchor assembly 2; the gravity anchor assembly 1 is used to be connected to the upper wind turbine and provide a stable gravity foundation and multi-degree-of-freedom rotation for the wind turbine; the top of the suction anchor assembly 2 is fixed to the bottom of the gravity anchor assembly 1 and is used to penetrate into the seabed at a target depth.

[0054] In the above embodiment, preferably, Figures 1 to 6 As shown, the gravity anchor assembly 1 includes: a steel channel 1-1, a reinforcing plate 1-3 and a multi-directional hinge structure 1-4; the steel channel 1-1 is a shell structure with openings on both the top and the bottom; a plurality of reinforcing plates 1-3 (see Figure 8 ) is arranged in the steel trough 1-1, and its two ends are respectively connected to the inner wall of the steel trough 1-1; a multi-directional hinge structure 1-4 is provided on the top of each reinforcing plate 1-3, and the multi-directional hinge structure 1-4 is used to connect with the wind turbine foundation and provide multi-degree-of-freedom rotation for the wind turbine; concrete blocks 1-5 are cast in the steel trough 1-1, and the concrete blocks 1-5 are used to provide a stable gravity foundation for the wind turbine.

[0055] In the above embodiment, preferably, Figure 7 As shown, the multi-directional hinge structure 1-4 includes an axial rotation device 1-4-1, a horizontal rotation device 1-4-2 and a navigation hole member 1-4-3; the axial rotation device 1-4-1 includes a base 1-4-1-1 and an axial rotation axis 1-4-1-2; the center of the base 1-4-1-1 is movably connected to the reinforcing plate 1-3 through the axial rotation axis 1-4-1-2; specifically, the base 1-4-1-1 rotates on the reinforcing plate 1-3;

[0056] The horizontal rotating device 1-4-2 includes a connecting piece 1-4-2-2 and a horizontal rotating shaft 1-4-2-1. The two connecting pieces 1-4-2-2 are respectively fixed on the base 1-4-1-1, and the connecting piece 1-4-2-2 is provided with a connecting hole 1-4-2-3; both ends of the horizontal rotating shaft 1-4-2-1 extend into the connecting holes 1-4-2-3 of the two connecting pieces, so that the horizontal rotating shaft 1-4-2-1 can be rotatably connected to the connecting piece 1-4-2-2;

[0057] The guide hole 1-4-3 is fixedly arranged on the horizontal rotating shaft 1-4-2-1, and is used to be connected to the upper wind turbine through a mooring chain.

[0058] In the above embodiment, preferably, the gravity anchor assembly 1 further includes lifting ears 1-2, which are respectively arranged on the outer wall of the steel channel 1-1 for lifting the composite anchor.

[0059] In the above embodiment, preferably, there are two lifting ears 1-2, and the lifting ears 1-2 are 0.1m away from the top of the steel channel 1-1.

[0060] In the above embodiment, preferably, Fig. 9 As shown, the suction anchor assembly includes: a cylinder cover 2-1 and a cylinder skirt 2-2; the cylinder cover 2-1 is arranged at the bottom of the steel trough 1-1; the cylinder skirt 2-2 is a cylindrical structure, the upper end of which is connected to the cylinder cover 2-1, and the lower end is penetrated into the seabed at the target depth.

[0061] In the above embodiment, preferably, a drainage hole 2-3 is also provided on the top of the tube skirt 2-2. Thus, seawater can be discharged during the self-weight penetration of the foundation, and during the negative pressure penetration, water can be pumped in the tube by connecting to a negative pressure pump to cause a pressure difference between the inside and outside of the tube, so that the composite foundation can be further penetrated to the designed depth; after the negative pressure pumping is completed, underwater grouting can be carried out through the drainage hole to fill the gap between the tube cover and the seabed, so as to give full play to the bearing capacity of the foundation.

[0062] It should be noted that the diameter of the tube cover is generally 6-8 meters, and the thickness is generally 0.5 meters; the height of the tube skirt is generally not more than 10 meters when used in sandy seabeds, and generally not more than 20 meters when used in clay seabeds. The tube wall thickness of the tube skirt is generally 0.3-0.5 meters; the drainage hole is located at the top of the tube skirt and has a diameter of 0.2 meters.

[0063] In the above embodiment, preferably, the outer diameter of the cross section of the tube skirt 2-2 is D, and the outer diameter of the cross section of the steel groove 1-1 is 1.5D-2D.

[0064] like Figures 12 to 15 As shown, the present invention also provides a method for installing a multi-degree-of-freedom mooring tensioned composite anchor, comprising the following steps:

[0065] Step 1: On the shore, concrete slurry is injected into the steel groove of the gravity anchor assembly equipped with a reinforcement plate and a multi-directional hinged structure, and the multi-directional hinged structure is exposed, and the suction anchor assembly is connected with the gravity anchor assembly. After the multi-degree-of-freedom mooring tensioned composite anchor is prefabricated as a whole, it is suspended to the transport ship by a steel cable;

[0066] Step 2: transport the multi-degree-of-freedom mooring tension composite anchor to the designated location by a transport ship, and slowly suspend it to the top of the installation location by the crane of the installation ship. During the lowering process, allow the seawater to be discharged through the drainage hole of the suction anchor assembly;

[0067] Step 3: Place the multi-degree-of-freedom mooring tensioned composite anchor on the seabed, and use its deadweight to make the suction anchor assembly penetrate into the seabed at the set penetration speed; the penetration speed should be controlled by the steel cable at this stage, and the penetration speed is generally 3m / min. A larger penetration speed will cause the foundation to cause local scouring of the sandy seabed, forming local gullies at the bottom of the foundation, reducing the effective penetration depth of the foundation, and affecting the in-situ bearing capacity of the foundation; a larger penetration speed will cause the foundation to cause greater disturbance to the surface soil of the clay seabed, affecting the bearing capacity of the foundation;

[0068] Step 4: After the penetration is completed, the sling is separated from the composite anchor by an underwater robot, and a suction pump is used to pump water out through the drainage hole. A pressure difference is generated inside and outside the suction anchor assembly. Under the action of the pressure difference, the multi-degree-of-freedom mooring tensioned composite anchor continues to penetrate into the seabed at the set penetration speed until the penetration is completed. The installation of the multi-degree-of-freedom mooring tensioned composite anchor is completed. Fig.16 This is a schematic diagram of the installation completion of the present invention. Fig.17 It is a schematic diagram of the present invention in service.

[0069] In the above embodiment, preferably, the installation method needs to overcome the penetration resistance of the seabed to the cylinder wall structure of the suction anchor assembly;

[0070] The penetration resistance of the multi-degree-of-freedom mooring tension composite anchor during the penetration process is obtained using the cone penetration test (CPT) data as follows:

[0071]

[0072] In the formula, k p k is the empirical coefficient of end resistance; f is the empirical coefficient of friction resistance; d is the penetration depth; A p A is the skirt end area of ​​the suction anchor assembly; s is the unit tube skirt side area; q c It is the cone tip resistance value measured by CPT.

[0073] It should be noted that in the above formula, the values ​​of kp and kf are greatly affected by the type of soil, and the recommended values ​​in sand and clay are quite different. The influence of seepage is taken into account in the selection of these design parameters, and the reduction of penetration resistance in sand can be considered, so this method has advantages such as simplicity and applicability for the installation design of the present invention. Therefore, the CPT method is used to calculate the penetration resistance of the multi-degree-of-freedom mooring tensioned composite anchor.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-degree-of-freedom mooring tensioned composite anchor, characterized in that: It includes a gravity anchor assembly and a suction anchor assembly; The gravity anchor assembly is used to be connected to the upper wind turbine and provide a stable gravity foundation and multi-degree-of-freedom rotation for the wind turbine; the top of the suction anchor assembly is fixed to the bottom of the gravity anchor assembly and is used to penetrate into the seabed at a target depth.

2. The multi-degree-of-freedom mooring tensioned composite anchor according to claim 1, characterized in that: The gravity anchor assembly comprises: a steel channel, a reinforcement plate and a multi-directional hinged structure; The steel trough is a shell structure with openings at the top and bottom; A plurality of reinforcing plates are arranged in the steel channel, and both ends are connected to the inner wall of the steel channel respectively; The top of each reinforcement plate is provided with the multi-directional hinge structure, which is used to connect with the wind turbine foundation and provide the wind turbine with multi-degree-of-freedom rotation; Concrete blocks are poured in the steel trough, and the concrete blocks are used to provide a stable gravity foundation for the fan.

3. The multi-degree-of-freedom mooring tensioned composite anchor according to claim 2, characterized in that: The multi-directional hinge structure includes an axial rotation device, a horizontal rotation device and a navigation hole; The axial rotation device comprises a base and an axial rotation shaft; the center of the base is movably connected to the reinforcing plate through the axial rotation shaft; The horizontal rotation device comprises a connecting piece and a horizontal rotation shaft, wherein the two connecting pieces are respectively fixed on the base, and the connecting pieces are provided with connecting holes; both ends of the horizontal rotation shaft extend into the connecting holes of the two connecting pieces, so that the horizontal rotation shaft can be rotatably connected with the connecting pieces; The navigation hole is fixedly arranged on the horizontal rotating shaft and is used to be connected with the upper fan through a mooring chain.

4. The multi-degree-of-freedom mooring tensioned composite anchor according to claim 2, characterized in that: The gravity anchor assembly also includes lifting ears, which are respectively arranged on the outer wall of the steel channel and are used for lifting the composite anchor.

5. The multi-degree-of-freedom mooring tensioned composite anchor according to claim 4, characterized in that: There are two lifting ears, and a distance between the lifting ears and the top of the steel trough is set.

6. The multi-degree-of-freedom mooring tensioned composite anchor according to claim 2, characterized in that: The suction anchor assembly comprises: a cylinder cover and a cylinder skirt; The cylinder cover is arranged at the bottom of the steel trough; The tube skirt is a cylindrical structure, the upper end of which is connected to the tube cover, and the lower end penetrates into the seabed at the target depth.

7. The multi-degree-of-freedom mooring tensioned composite anchor according to claim 6, characterized in that: The top of the tube skirt is also provided with a drainage hole.

8. The multi-degree-of-freedom mooring tensioned composite anchor according to claim 6, characterized in that: The outer diameter of the cross section of the tube skirt is D, and the outer diameter of the cross section of the steel channel is 1.5D-2D.

9. A method for installing a multi-degree-of-freedom mooring tensioned composite anchor according to any one of claims 2 to 8, characterized in that: The steps include: On the shore, concrete slurry is injected into the steel groove of the gravity anchor assembly equipped with a reinforcement plate and a multi-directional hinged structure, and the multi-directional hinged structure is exposed, and the suction anchor assembly is connected with the gravity anchor assembly. After the multi-degree-of-freedom mooring tensioned composite anchor is prefabricated as a whole, it is suspended to the transport ship by a steel cable; The multi-degree-of-freedom mooring tension composite anchor is transported to the designated location by a transport ship, and slowly suspended to the top of the installation location by the crane of the installation ship. During the lowering process, seawater is allowed to be discharged through the drainage holes of the suction anchor assembly. The multi-degree-of-freedom mooring tensioned composite anchor is placed on the seabed, and combined with its own weight, the suction anchor assembly is penetrated into the seabed at a set penetration speed; When the penetration is completed, the sling is separated from the composite anchor by an underwater robot, and a suction pump is used to pump water out through the drainage hole. A pressure difference is generated inside and outside the suction anchor assembly. Under the action of the pressure difference, the multi-degree-of-freedom mooring tensioned composite anchor continues to penetrate into the seabed at the set penetration speed until the penetration is completed. The installation of the multi-degree-of-freedom mooring tensioned composite anchor is completed.

10. The installation method according to claim 9, characterized in that: The installation method needs to overcome the penetration resistance of the seabed to the cylinder wall structure of the suction anchor assembly; The penetration resistance of the multi-degree-of-freedom mooring tension composite anchor during the penetration process is obtained using the static penetration test data: In the formula, k p k is the empirical coefficient of end resistance; f is the empirical coefficient of friction resistance; d is the penetration depth; A p A is the skirt end area of ​​the suction anchor assembly; s is the unit tube skirt side area; q c It is the cone tip resistance value measured by CPT.

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