Tension leg platform suction pile anchoring foundation and offshore construction method

Abstract

The invention discloses a tension leg platform suction pile anchoring foundation and an offshore construction method, and relates to the technical field of ocean engineering. The base structure is fixed to the top of the mud entering steel structure. The base structure is of a double-wall cylindrical structure, a ballast tank is arranged in the base structure, and a ballast system is arranged in the ballast tank; a drainage pipeline is further arranged in the base structure and communicates with the interior of the mud inlet steel structure and the water suction pump. A lug plate structure is arranged on the side wall of the base structure; the mud entering steel structure is of a single-layer wall cylindrical structure, and the cylindrical opening direction of the mud entering steel structure is opposite to the cylindrical opening direction of the base structure; and a to-be-mounted counterweight is placed in the upper opening structure of the base structure. The technical problem that a traditional suction pile anchoring foundation is not suitable for a tension leg type floating platform including a floating wind power platform due to the fact that the axial pulling resistance capacity is limited by a suction barrel structure type, an installation mode and soil conditions is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of marine engineering, and in particular to a tension leg platform suction pile anchor foundation and an offshore construction method. Background Art

[0002] Suction pile anchor foundation is widely used in marine engineering, providing anchor foundation for positioning of marine engineering structures. Its structure is a steel cylindrical structure with closed upper end and open lower end. Under the deadweight of the anchor foundation, the barrel wall penetrates into the seabed soil to form a closed space, and then the liquid in the closed space is pumped out by a pump, so that the closed space forms a pressure difference with the outside, so that the external pressure further penetrates the barrel wall deeper into the seabed soil.

[0003] The design features of traditional suction pile anchor foundations are as follows: 1) The deadweight of the anchor foundation structure penetrates the barrel wall into the seabed soil to a certain depth, forming a closed space; 2) The closed space can form a sufficiently large internal and external pressure difference to overcome the friction between the barrel wall and the soil and press the suction barrel to the designed depth. The above two points make the depth to which the traditional suction barrel anchor foundation can penetrate into the soil under a given suction barrel diameter depend on the soil conditions, which in turn determines the axial pull-out resistance of the traditional anchor foundation. In order to ensure the stability of the tension leg wind turbine platform, the mooring cable (chain) of the tension leg wind turbine platform must always be kept in a tensioned state, which requires the anchor foundation of the tension leg wind turbine platform to have a large axial pull-out resistance. For example, the anchor foundation of a 15 MW tension leg floating wind turbine platform needs to have an axial pull-out resistance of more than several thousand tons.

[0004] Generally speaking, traditional suction pile anchor foundations have good horizontal load resistance and are more suitable for use in clay soils, but not in sandy soils. As a result, suction pile foundations with high axial pull-out resistance designed according to traditional schemes can only be used in a few areas with particularly good soil conditions, limiting the application areas of suction pile foundations with high axial pull-out resistance. Generally speaking, traditional suction pile anchor foundations are not suitable for tension leg type floating platforms (including floating wind power platforms). Summary of the invention

[0005] The purpose of the present invention is to provide a tension leg platform suction pile anchor foundation and an offshore construction method in order to solve at least one of the above technical problems.

[0006] In the first aspect, an embodiment of the present invention provides a tension leg platform suction pile anchor foundation, comprising: a base structure and a mud-entering steel structure; the base structure is fixed to the top of the mud-entering steel structure; the base structure is a double-walled cylindrical structure, a ballast tank is arranged inside the base structure, and a ballast system is arranged inside the ballast tank; a drainage pipeline is also arranged inside the base structure, one end of the drainage pipeline passes through the bottom of the base structure and is connected to the interior of the mud-entering steel structure, and the other end of the drainage pipeline passes through the top of the base structure and is connected to a water pump; an ear plate structure is arranged on the side wall of the base structure; the mud-entering steel structure is a single-walled cylindrical structure, and the cylindrical opening direction of the mud-entering steel structure is opposite to that of the cylindrical opening direction of the base structure; a counterweight to be installed is placed inside the upper opening structure of the base structure.

[0007] Furthermore, the base structure is a steel plate shell structure, and the inner side wall of the base structure is provided with a structure matching with different counterweights to be installed, for fixing the counterweights to be installed and transferring the deadweight of the counterweights to be installed to the base structure; the mud-entering steel structure is a steel plate shell structure.

[0008] Furthermore, a flange is provided at the port of the drainage pipeline connected to the top of the base structure, and the top port of the drainage pipeline is connected to an external pipeline connected to the water pump through the flange.

[0009] Furthermore, the ear plate structure includes a horizontal eye plate arranged on the outer side wall of the base structure and a vertical eye plate arranged on the top edge of the base structure; the horizontal eye plate is used to connect a mooring cable or a mooring chain; the vertical eye plate is used to assist in fixing the device for placing the counterweight to be installed.

[0010] Furthermore, the ballast system includes a first pipeline and a first sea valve; wherein the first sea valve is arranged on the outer side wall of the base structure, and the first pipeline is connected to the first sea valve.

[0011] Furthermore, the ballast system also includes a ventilation pipe, one end of which extends into the interior of the ballast tank, and the other end of which passes through the top of the base structure and is connected to the outside of the ballast tank.

[0012] Furthermore, the counterweight to be installed includes iron ore or cement.

[0013] Furthermore, the base structure also includes a buoyancy tank, which is arranged on the top of the ballast tank; wherein the buoyancy tank is an internal hollow structure, and a second sea valve and a second pipeline connected to the second sea valve are arranged on the outer wall, and the second pipeline passes through the outer wall and the inner wall of the buoyancy tank and is connected to the interior of the upper opening structure of the base structure.

[0014] In the second aspect, an embodiment of the present invention further provides an offshore construction method for a tension leg platform suction pile anchor foundation, which is applied to a tension leg platform suction pile anchor foundation provided by the present invention; the method comprises: setting the interior of the ballast tank to be empty or partially empty, so that the base structure floats on the sea surface relying on the buoyancy of the ballast tank; wet-towed the tension leg platform suction pile anchor structure from the launching site to the operating sea area by a tugboat; increasing the ballast water in the ballast tank at a preset rate through the ballast system, so that the base structure together with the mud-entering steel structure gradually sinks to the seabed anchoring point and penetrates into the seabed soil; constructing a counterweight placement channel, and placing the counterweight to be installed into the upper opening of the base structure through the counterweight placement channel, so as to increase the depth of the mud-entering steel structure penetrating into the seabed soil; discharging the seawater between the mud-entering steel structure and the seabed soil through the water pump and the drainage pipeline, so as to increase the depth of the mud-entering steel structure penetrating into the seabed soil.

[0015] In the third aspect, an embodiment of the present invention further provides an offshore construction method for a tension leg platform suction pile anchor foundation, which is applied to a tension leg platform suction pile anchor foundation provided by the present invention; the method comprises: dry-towing the tension leg platform suction pile anchor foundation to the operating sea area by a work boat; connecting the crane of the work boat based on the ear plate structure, and lowering the tension leg platform suction pile anchor foundation from the water surface to the seabed anchor point by the crane; constructing a counterweight placement channel, and placing the counterweight to be installed into the upper opening of the base structure through the counterweight placement channel to increase the penetration depth of the mud-entering steel structure into the seabed soil; discharging the seawater between the mud-entering steel structure and the seabed soil by the water pump and the drainage pipeline to increase the penetration depth of the mud-entering steel structure into the seabed soil.

[0016] The present invention provides a tension leg platform suction pile anchor foundation and an offshore construction method, which increases the penetration depth of the suction pile anchor foundation in the seabed soil by means of a counterweight to be installed, and further increases the penetration depth of the suction pile anchor foundation in the seabed soil by means of a drainage pipeline and a water pump, thereby solving the problem of poor axial pullout resistance of the suction pile anchor foundation, expanding the application scope of the suction pile anchor foundation, and allowing the suction pile anchor foundation to be applied to the tension leg platform. Compared with driven piles, the present invention is convenient for offshore installation and solves the problem that the axial bearing capacity of the suction pile anchor foundation is relatively weak and is not suitable for the tension leg platform. At the same time, the form of the counterweight to be installed makes the base structure itself lighter, and the ballast tank and buoyancy tank structure are set to realize the self-floating of the base structure, and can be used for tugboats to complete wet towing transportation and offshore installation operations. It has the advantage of not needing to use large equipment such as floating cranes, making sea surface transportation of the base structure more convenient, reducing the equipment requirements and costs for offshore operations, and has economic advantages. It alleviates the technical problem that the axial pull-out resistance of traditional suction pile anchor foundations is limited by the suction bucket structure type, installation method and soil conditions and is not suitable for tension leg type floating platforms including floating wind power platforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A side view of a tension leg platform suction pile anchor foundation provided by an embodiment of the present invention;

[0019] Figure 2 A side view of a base structure provided by an embodiment of the present invention;

[0020] Figure 3 A top view of the distribution of a first pipeline inside a ballast tank provided by an embodiment of the present invention;

[0021] Figure 4 A top view of a base structure provided by an embodiment of the present invention;

[0022] Figure 5 A partial enlarged view of a side wall portion of a base structure provided by an embodiment of the present invention;

[0023] Figure 6 A flow chart of an offshore construction method for a tension leg platform suction pile anchor foundation provided by an embodiment of the present invention;

[0024] Figure 7 A flow chart of an offshore construction method for a tension leg platform suction pile anchor foundation provided by an embodiment of the present invention.

[0025] In the figure: 1. base structure, 2. mud entry steel structure, 3. ballast tank, 4. first pipeline, 5. first sea valve, 6. vent pipe, 7. drainage pipeline, 8. water pump, 9. horizontal eye plate, 10. vertical eye plate, 11. tugboat, 12. external pipeline, 13. buoyancy tank, 14. second sea valve, 15. second pipeline, 16. upper opening structure. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Embodiment 1

[0028] Figure 1 FIG. 1 is a side view of a tension leg platform suction pile anchor foundation provided according to an embodiment of the present invention. Figure 1 As shown, it includes: a base structure 1 and a mud-entering steel structure 2; the base structure 1 is fixed on the top of the mud-entering steel structure 2.

[0029] Specifically, the base structure 1 is a double-walled cylindrical structure, including an upper opening structure 16 , and the bottom of the upper opening structure 16 is closed.

[0030] Optionally, the base structure 1 includes any polygonal cylindrical structure (such as a square cylindrical structure), or a cylindrical structure, or an irregular cylindrical structure.

[0031] Preferably, the base structure 1 is a double-walled cylindrical steel plate shell structure; and the mud entering steel structure 2 is a single-walled cylindrical steel plate shell structure.

[0032] Specifically, the counterweight to be installed is placed inside the upper opening structure 16 of the base structure 1 .

[0033] Optionally, the counterweight to be installed includes iron ore or cement, etc. In the embodiment of the present invention, the type of the counterweight to be installed can be selected according to actual needs.

[0034] Specifically, the inner side wall of the base structure 1 is provided with a structure matching with different counterweights to be installed, and used for fixing the counterweights to be installed and transferring the deadweight of the counterweights to be installed to the base structure 1 .

[0035] In the embodiment of the present invention, the cylindrical structure of the base structure 1 can be used to carry the counterweight to be installed, so as to improve the axial pull-out resistance of the suction pile anchor foundation. Among them, the separate design and distributed installation of the counterweight to be installed make it unnecessary for the base structure 1 to carry the counterweight during the construction, launching and offshore installation stages, so that the design of the base structure 1 is optimized, the base structure 1 can float by itself, and the transportation cost of the suction pile anchor foundation is reduced, and the demand for offshore installation equipment is reduced by avoiding the use of large floating crane equipment.

[0036] Figure 2 is a side view of a base structure provided according to an embodiment of the present invention. Figure 2 As shown, a ballast tank 3 is arranged inside the base structure, and a ballast system is arranged inside the ballast tank 3. Specifically, Figure 2 As shown, the ballast system includes a first pipeline 4 and a first sea valve 5 ; wherein the first sea valve 5 is arranged on the outer side wall of the base structure 1 , and the first pipeline 4 is connected to the first sea valve 5 .

[0037] Figure 3 FIG. 1 is a top view of the distribution of a first pipeline inside a ballast tank according to an embodiment of the present invention. Figure 3 As shown, in an embodiment of the present invention, one end of the first pipeline 4 is connected to the first sea valve 5, and the other end of the first pipeline 4 is provided with multiple ports and evenly distributed at multiple points inside the ballast tank 3, so as to guide the ballast water of the first sea valve 5 through the first pipeline 4 and penetrate the ballast water into the ballast tank 3 relatively evenly.

[0038] Optionally, the ballast tank 3, the first sea valve 5 and the first pipeline 4 are each provided with at least one, and a first sea valve 5 is provided on the side wall of each ballast tank 3. After the first sea valve 5 is opened underwater, seawater enters the ballast tank 3 through the first pipeline 4.

[0039] Specifically, the ballast system is used to adjust the ballast water and buoyancy of the base structure 1 so that the base structure 1 can float or sink during the installation process.

[0040] like Figure 2 As shown, the base structure 1 further includes a buoyancy tank 13, which is arranged on the top of the ballast tank 3. Specifically, the buoyancy tank 13 is an internal hollow structure, and a second sea valve 14 and a second pipeline 15 connected to the second sea valve 14 are arranged on the outer wall. The second pipeline 15 passes through the outer wall and the inner wall of the buoyancy tank 13 and communicates with the interior of the upper opening structure 16 of the base structure 1. After the second sea valve 14 is opened, seawater will enter the space inside the upper opening structure 16 of the base structure 1 through the second pipeline 15.

[0041] in, Figure 2 The dotted line in FIG. 1 is the setting direction of the first pipeline 4 and the second pipeline 15 .

[0042] It should be noted that one end of the second pipeline 15 is connected to the second sea valve 14, and the other end of the second pipeline 15 passes through the buoyancy tank 13 and is connected to the inner wall, and the second pipeline 15 connected to the second sea valve 14 is closed in the middle section inside the buoyancy tank 13, and seawater will not be pumped into the buoyancy tank 13. The second pipeline 15 is only used to establish a passage together with the outer wall sea valve and the inner wall.

[0043] Alternatively, if Figure 2 As shown, the ballast system further includes a vent pipe 6 , one end of which extends into the ballast tank 3 , and the other end of which passes through the top of the base structure 1 and communicates with the outside of the ballast tank 3 .

[0044] Specifically, Figure 1 As shown, a drainage pipeline 7 is also arranged inside the base structure 1 , one end of the drainage pipeline 7 passes through the bottom of the base structure 1 and is connected to the interior of the mud steel structure 2 , and the other end of the drainage pipeline 7 passes through the top of the base structure 1 and is connected to a water pump 8 .

[0045] In an optional implementation provided by an embodiment of the present invention, a flange is provided at the port of the drainage pipeline 7 connected to the top of the base structure 1, and the top port of the drainage pipeline 7 is connected to an external pipeline 12 connected to the water pump 8 through the flange.

[0046] In the embodiment of the present invention, the drainage pipeline 7 and the external pipeline 12 are detachably arranged.

[0047] Specifically, the drainage pipeline 7 and the water pump 8 can pump out the seawater in the closed space between the mud-entering steel structure 2 and the seabed soil, forming an internal and external pressure difference to enhance the horizontal force resistance and axial pull-out resistance of the tension leg platform suction pile anchor foundation.

[0048] Specifically, an ear plate structure is provided on the side wall of the base structure 1 .

[0049] Figure 4 is a top view of a base structure provided according to an embodiment of the present invention, Figure 5 FIG. 1 is a partial enlarged view of a side wall portion of a base structure provided according to an embodiment of the present invention. Figure 4 and Figure 5 As shown, the ear plate structure includes a horizontal eye plate 9 arranged on the outer side wall of the base structure 1 and a vertical eye plate 10 arranged on the top edge of the base structure 1 .

[0050] Specifically, the horizontal eye plate 9 is used to connect the mooring cable or mooring chain;

[0051] The vertical eye plate 10 is used to assist in fixing a device for placing a counterweight to be installed. For example, the vertical eye plate 10 can be used to fix a hose for placing a counterweight to be installed.

[0052] Alternatively, if Figure 4 As shown, the outer side wall of the base structure 1 is evenly provided with a plurality of horizontal eye plates 9 along the circumferential direction, for example, three horizontal eye plates 9 are connected to the mooring cable or mooring chain connected to the tugboat 11 .

[0053] In an optional implementation provided by an embodiment of the present invention, the outer wall diameter of the base structure is 15m, the inner wall diameter is 10m, the total height of the base structure is 15m, the inner wall height is 10m, and the length of the mud-entering steel structure is 15m.

[0054] The tension leg platform suction pile anchor foundation provided by the present invention has the following advantages compared with the prior art:

[0055] (1) A counterweight that can be permanently placed on the base is added to the base structure. The counterweight improves the axial pull-out resistance of the suction pile anchor foundation, solving the problem that the axial pull-out resistance of the traditional suction pile anchor foundation is limited by soil conditions, structural design and installation methods and is not suitable for tension leg platforms. This expands the application scope of the suction pile anchor foundation.

[0056] (2) The load conditions of the base structure during the construction, transportation and offshore installation stages are optimized through the counterweights to be installed, thus achieving structural design optimization. The form of the counterweights to be installed makes the base structure itself lighter, reducing the length design restrictions of the steel structure due to the self-weight of the structure; specifically, the deeper the penetration of the steel structure into the soil, the better the tensile and horizontal resistance of the structure, but the length design of the steel structure needs to consider the effects of loads such as the self-weight of the anchor foundation loaded on the steel structure. The detachable counterweights make the weight of the base structure and the steel structure lighter, and during the installation of the anchor point, the counterweights can be gradually and slowly loaded on the base structure, so that a longer steel structure can be designed, which enhances the efficiency of the structure in resisting horizontal forces and tensile forces.

[0057] (3) The present invention provides a structure that can permanently bear a counterweight, and the counterweight can be used to further increase the penetration depth of the suction pile anchor foundation into the seabed soil. This allows the design to be carried out in soil conditions such as sandy soil that are not conducive to the suction pile anchor foundation without the need to use large offshore equipment to carry out piling operations. The weight of the counterweight can also reach the designed penetration depth of the mud-entering steel structure into the seabed soil, thereby improving the adaptability of the suction pile anchor foundation to soil conditions.

[0058] (4) The present invention is provided with a ballast tank and a buoyancy tank structure, which can realize the self-floating of the base structure, and can be used for tugboats to complete wet towing transportation and offshore installation operations, and use the deadweight, detachable counterweight and the pressure difference generated by the water pump to complete the underwater installation. There is no need to use a large floating crane or carry out piling operations, which reduces the demand for offshore installation equipment, shortens the construction period of offshore installation, and reduces the cost of offshore installation.

[0059] Embodiment 2

[0060] Figure 6 1 is a flow chart of an offshore construction method for a tension leg platform suction pile anchor foundation provided in accordance with an embodiment of the present invention. The method is applied to a tension leg platform suction pile anchor foundation provided in accordance with an embodiment of the present invention. Figure 6 As shown, the method specifically comprises the following steps:

[0061] Step S602, setting the interior of the ballast tank to be empty or partially empty, so that the base structure floats on the sea surface relying on the buoyancy of the ballast tank.

[0062] Step S604: wet-tow the tension leg platform suction pile anchoring structure from the launching site to the operating sea area by a tugboat.

[0063] Specifically, the base structure can be internally provided with a single or multiple ballast tanks and ballast systems according to specific application conditions, and an ear plate structure can be provided on the outer wall of the base structure, so that the base structure has buoyancy, self-stability and load adjustment capabilities. After launching, a tow cable can be used to connect the horizontal eye plate on the side wall of the base structure and the tow hook of the tugboat, and the tugboat can be wet-towed from the launching site to the operating sea area.

[0064] Step S606, in the operating sea area, the base structure is limited by tugboats and tow cables, and the ballast water in the ballast tank is increased at a preset rate through the ballast system, so that the base structure connected to the mud-entering steel structure gradually sinks to the seabed anchoring point and penetrates into the seabed soil.

[0065] Specifically, at the installation site, three tugboats can be used, each of which is connected to the horizontal eye plate on the side wall of the base structure through a tow cable. The three tugboats are arranged in a herringbone shape around the base structure to achieve the control of the horizontal position of the base structure in the sea through the mutual coordination of the three tugboats.

[0066] The ballast water in the ballast tank is then increased at a preset rate through the ballast system, and under the coordinated control of the three tugboats through the tension adjustment of the towline, the base structure together with the mud-entering steel structure gradually sinks to the seabed anchoring point and penetrates into the seabed soil.

[0067] In an optional implementation provided by an embodiment of the present invention, three tugboats surround the base structure in a herringbone shape to fix the relative position of the base structure in the operating sea area; then the ballast water in the base structure is gradually increased to gradually immerse the base structure; a partial fixed ballast can be set inside the base structure so that when the base structure is fully immersed, the center of gravity of the whole composed of the base structure, the mud-entering steel structure, the ear plate structure and the eye plate auxiliary structure is lower than the center of buoyancy to form sufficient self-stability.

[0068] Then, after all the ballast water is pumped into the base structure, the mud-entering steel structure relies on its own weight to penetrate into the seabed soil.

[0069] In the embodiment of the present invention, the process of injecting ballast water into the ballast tank to gradually sink the anchor foundation into the seabed is a slow and controlled process, which ensures that the base structure can sink to a preset location.

[0070] Step S608, constructing a counterweight placement channel, and placing the counterweight to be installed into the upper opening of the base structure through the counterweight placement channel to increase the penetration depth of the mud-entering steel structure into the seabed soil.

[0071] Specifically, a counterweight placement channel is established from the surface ship to the counterweight placement location in the base structure using a surface ship and a hose, and a vertical eye plate is provided on the upper part of the base structure for fixing the hose. Counterweights such as iron ore or cement are transported to the counterweight placement location in the base structure through a hose or other structures with equivalent functions, and the depth of penetration of the mud-entering steel structure into the seabed soil is further increased by the increasing weight of the counterweight.

[0072] Step S610, draining the seawater between the mud-entering steel structure and the seabed soil through a pump and a drainage pipeline to increase the penetration depth of the mud-entering steel structure into the seabed soil.

[0073] Specifically, the flange between the surface ship and the top of the base structure can be connected through a hose or other structure with equivalent functions to discharge the liquid in the closed space formed by the mud-entering steel structure and the seabed soil through a pump, thereby forming an internal and external pressure difference, and further increasing the depth of the mud-entering steel structure penetrating into the seabed soil.

[0074] In an optional implementation provided by an embodiment of the present invention, the above steps S508 and S510 can be performed alternately or in steps until the steel structure penetrates the seabed soil to a designed depth and the counterweight in the base structure reaches a designed weight.

[0075] Embodiment 3

[0076] Figure 7 1 is a flow chart of an offshore construction method for a tension leg platform suction pile anchor foundation provided in accordance with an embodiment of the present invention. The method is applied to a tension leg platform suction pile anchor foundation provided in accordance with an embodiment of the present invention. Figure 7 As shown, the method specifically comprises the following steps:

[0077] Step S702: Dry-tow the tension leg platform suction pile anchor foundation to the operating sea area by a workboat.

[0078] Specifically, it can be determined whether to place a portion of ballast such as iron ore or cement in advance on the portion of the base structure where the ballast is to be placed, based on specific application conditions, such as the capacity of the crane and the size and deadweight of the base structure.

[0079] Step S704: connect the crane of the workboat based on the ear plate structure, and lower the tension leg platform suction pile anchor foundation from the water surface to the seabed anchor point through the crane. At this time, the mud-entering steel structure penetrates into the seabed soil by the deadweight of the base structure.

[0080] Step S706, constructing a counterweight placement channel, and placing the counterweight to be installed into the upper opening of the base structure through the counterweight placement channel to increase the penetration depth of the mud-entering steel structure into the seabed soil.

[0081] Step S708, draining the seawater between the mud-entering steel structure and the seabed soil through a pump and a drainage pipeline to increase the penetration depth of the mud-entering steel structure into the seabed soil.

[0082] In an optional implementation provided by an embodiment of the present invention, the above steps S606 and S608 can be performed alternately or in steps until the steel structure penetrates the seabed soil to a designed depth and the counterweight in the base structure reaches a designed weight.

[0083] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0084] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A tension leg platform suction pile anchor foundation, characterized in that: include: A base structure and a mud-entering steel structure; the base structure is fixed to the top of the mud-entering steel structure; The base structure is a double-walled cylindrical structure, a ballast tank is arranged inside the base structure, and a ballast system is arranged inside the ballast tank; a drainage pipeline is also arranged inside the base structure, one end of the drainage pipeline passes through the bottom of the base structure and is connected to the inside of the mud-entering steel structure, and the other end of the drainage pipeline passes through the top of the base structure and is connected to a water pump; An ear plate structure is provided on the side wall of the base structure; The mud-entering steel structure is a single-wall cylindrical structure, and the cylindrical opening direction of the mud-entering steel structure is opposite to the cylindrical opening direction of the base structure; the counterweight to be installed is placed inside the upper opening structure of the base structure.

2. The tension leg platform suction pile anchor foundation according to claim 1, characterized in that: The base structure is a steel plate shell structure, and the inner side wall of the base structure is provided with a structure matching with different counterweights to be installed, used for fixing the counterweights to be installed and transferring the deadweight of the counterweights to be installed to the base structure; The mud entering steel structure is a steel plate shell structure.

3. The tension leg platform suction pile anchor foundation according to claim 1, characterized in that: A flange is provided at the port of the drainage pipeline connected to the top of the base structure, and the top port of the drainage pipeline is connected to an external pipeline connected to the water pump through the flange.

4. The tension leg platform suction pile anchor foundation according to claim 1, characterized in that: The lug plate structure includes a horizontal eye plate disposed on the outer side wall of the base structure and a vertical eye plate disposed on the top edge of the base structure; The horizontal eye plate is used to connect a mooring line or a mooring chain; The vertical eye plate is used to assist in fixing the device for placing the counterweight to be installed.

5. The tension leg platform suction pile anchor foundation according to claim 1, characterized in that: The ballast system includes a first pipeline and a first sea valve; wherein the first sea valve is arranged on the outer side wall of the base structure, and the first pipeline is connected to the first sea valve.

6. The tension leg platform suction pile anchor foundation according to claim 1, characterized in that: The ballast system also includes a ventilation pipe, one end of which extends into the interior of the ballast tank, and the other end of which passes through the top of the base structure and communicates with the outside of the ballast tank.

7. The tension leg platform suction pile anchor foundation according to claim 1, characterized in that: The counterweight to be installed includes iron ore or cement.

8. The tension leg platform suction pile anchor foundation according to claim 1, characterized in that: The base structure also includes a buoyancy tank, which is arranged on the top of the ballast tank; wherein the buoyancy tank is an internal hollow structure, and a second sea valve and a second pipeline connected to the second sea valve are arranged on the outer wall, and the second pipeline passes through the outer wall and the inner wall of the buoyancy tank and is connected to the interior of the upper opening structure of the base structure.

9. An offshore construction method for a tension leg platform suction pile anchor foundation, characterized in that: A tension leg platform suction pile anchor foundation applied to claim 1; the method comprising: The ballast tank is set to be empty or partially empty inside, so that the base structure floats on the sea surface by relying on the buoyancy of the ballast tank; Wet-tow the tension leg platform suction pile anchoring structure from the launching site to the operating sea area by a tugboat; In the operating sea area, the base structure is limited by the tugboat and the tow cable, and the ballast water in the ballast tank is increased at a preset rate by the ballast system, so that the base structure together with the mud-entering steel structure gradually sinks to the seabed anchoring point and penetrates into the seabed soil; Constructing a counterweight placement channel, and placing the counterweight to be installed into the upper opening of the base structure through the counterweight placement channel to increase the penetration depth of the mud-entering steel structure into the seabed soil; The seawater between the mud-entering steel structure and the seabed soil is discharged through the water pump and the drainage pipeline to increase the penetration depth of the mud-entering steel structure into the seabed soil.

10. An offshore construction method for a tension leg platform suction pile anchor foundation, characterized in that: A tension leg platform suction pile anchor foundation applied to claim 1; the method comprising: The tension leg platform suction pile anchor foundation is dry-towed to the operating sea area by a workboat; A crane is connected to the workboat based on the ear plate structure, and the tension leg platform suction pile anchor foundation is lowered from the water surface to the seabed anchoring point by the crane; Constructing a counterweight placement channel, and placing the counterweight to be installed into the upper opening of the base structure through the counterweight placement channel to increase the penetration depth of the mud-entering steel structure into the seabed soil; The seawater between the mud-entering steel structure and the seabed soil is discharged through the water pump and the drainage pipeline to increase the penetration depth of the mud-entering steel structure into the seabed soil.

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