An offshore wind power combined foundation and construction method thereof

Abstract

An offshore wind power combined foundation and a construction method thereof, relating to the field of wind power generation. The offshore wind power combined foundation comprises a single pile foundation and at least three auxiliary spiral piles arranged at intervals along the circumference of the single pile foundation, the auxiliary spiral piles are connected to the single pile foundation, and the auxiliary spiral piles comprise an auxiliary spiral pile shell, a top plate arranged in the auxiliary spiral pile shell, a driving mechanism for driving the top plate to move axially along the auxiliary spiral pile, a ball screw rod that presses the top plate against the top plate, a ball screw nut that is threadedly sleeved on the ball screw rod, and an auger rod connected to the top and the bottom of the ball screw rod, the bottom of which extends below the auxiliary spiral pile shell. The offshore wind power combined foundation and the construction method thereof provided by the present application have the advantages of high bearing capacity, strong pull-out resistance, good stability and reliability, and convenient construction and maintenance, which can save installation time and reduce operation and maintenance costs.

Description

Technical Field

[0001] The present application relates to the field of wind power generation, and in particular, to an offshore wind power combined foundation and a construction method thereof. Background Art

[0002] Among the offshore wind power projects that have been built in my country, more than 60% use monopile foundations in whole or in part. However, as the monopile foundation develops towards "large diameter, extra-long, and deep penetration", its original features of convenient construction and high bearing capacity are no longer advantageous compared to the high construction cost. Therefore, the composite foundation has gradually become a new choice for wind turbine foundation structures.

[0003] The combined foundation consists of a single pile foundation and a shallow foundation. Common shallow foundations include bucket foundations, box foundations, and screw piles. Bucket foundations are often used because they can effectively resist horizontal loads and have good anti-overturning capabilities. However, the installation of such combined foundations requires large equipment to level the seabed, and requires accurate prediction of the sinking resistance, critical suction, and possible structural deformation during construction under complex soil conditions. When screw piles are used in shallow foundations, the foundation's pull-out resistance can be greatly increased to cope with complex marine environments. However, when installing such screw piles, not only underwater operations are required, but the construction difficulty is still high. For example, a fairly high degree of precision is required to ensure that the pins and pin holes of the screw pile mounting base are docked, which increases the construction difficulty and installation costs. Although the use of screw piles can cope with complex geological conditions well, it brings about a variety of problems such as complex construction technology and high cost of underwater installation of screw piles.

[0004] Therefore, there is a need for an offshore wind power combined foundation and a construction method thereof with high bearing capacity, simple construction technology and low construction cost. Summary of the invention

[0005] The purpose of this application is to provide an offshore wind power combined foundation and a construction method thereof, which has the advantages of high bearing capacity, strong pull-out resistance, good stability and reliability, and convenient construction and maintenance, and can save installation time and reduce operation and maintenance costs.

[0006] This application is implemented as follows:

[0007] The present application provides an offshore wind power combined foundation, which includes a single pile foundation and at least three auxiliary spiral piles arranged at intervals along the circumference of the single pile foundation, the auxiliary spiral piles are connected to the single pile foundation, the auxiliary spiral piles include an auxiliary spiral pile shell, a top plate arranged in the auxiliary spiral pile shell, a driving mechanism for driving the top plate to move axially along the auxiliary spiral pile, a ball screw rod with a top pressing the top plate, a ball screw nut arranged on the ball screw rod through a threaded sleeve, and an auger rod connected at the top to the bottom of the ball screw rod, and the bottom of the auger rod extends below the auxiliary spiral pile shell.

[0008] In some optional embodiments, at least one auxiliary screw pile base for pressing against the ground is provided below the auxiliary screw pile shell, and the ball screw nut in the auxiliary screw pile shell is connected to the corresponding auxiliary screw pile base through a base pressure transmission rod.

[0009] In some optional implementation schemes, a platform is fixedly provided on the monopile foundation, and the top of the auxiliary screw pile shell is connected to the platform through a connecting pipe.

[0010] In some optional embodiments, the outer wall of the monopile foundation is connected to a plurality of side wings spaced apart along its circumference.

[0011] In some optional embodiments, the side wings are isosceles trapezoidal plates whose lower bottom edges are connected to the outer wall of the monopile foundation.

[0012] In some optional embodiments, the length ratio of the upper and lower bases of the wing is 0.8-0.9, the length of the lower base of the wing is 1 / 5-1 / 4 of the length of the single pile foundation, and the ratio of the height of the wing to the length of the lower base is 0.2-0.25.

[0013] In some optional embodiments, the auger drilling rod includes a rotating rod body and a spiral blade connected to the outer wall of the rotating rod body. The outer diameter of the spiral blade gradually decreases as it extends downward, and the minimum diameter of the spiral blade is above 30 cm.

[0014] In some optional embodiments, the monopile foundation includes an exposed section, an embedded section, and an inverted cone section that are connected in sequence.

[0015] The present application also provides a construction method for an offshore wind power combined foundation, which is carried out using the above-mentioned offshore wind power combined foundation, and comprises the following steps:

[0016] After determining the installation location, drive the monopile foundation vertically downward into the ground;

[0017] When the auger drilling rod of each auxiliary screw pile contacts the ground, the control driving mechanism drives the corresponding top plate to move downward along the axial direction of the auxiliary screw pile, pushing the auger drilling rod to rotate and move downward along the axial direction of the auxiliary screw pile to drill to a predetermined depth.

[0018] In some optional embodiments, before the single pile foundation is driven vertically downward into the ground, at least one auxiliary screw pile base for pressing against the ground is provided below the auxiliary screw pile shell, and the auxiliary screw pile base is connected to the ball screw nut in the corresponding auxiliary screw pile shell.

[0019] The beneficial effects of the present application are as follows: the offshore wind power combined foundation provided by the present application includes a single pile foundation and at least three auxiliary spiral piles arranged at intervals along the circumference of the single pile foundation, the auxiliary spiral piles are connected to the single pile foundation, the auxiliary spiral piles include an auxiliary spiral pile shell, a top plate arranged in the auxiliary spiral pile shell, a driving mechanism for driving the top plate to move axially along the auxiliary spiral pile, a ball screw rod pressing the top plate at the top, a ball screw nut arranged on the ball screw rod through a threaded sleeve, and an auger rod connected at the top to the bottom of the ball screw rod, and the bottom of the auger rod extends below the auxiliary spiral pile shell. The offshore wind power combined foundation and the construction method thereof provided by the present application have the advantages of high bearing capacity, strong pull-out resistance, good stability and reliability, and convenient construction and maintenance, which can save installation time and reduce operation and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A structural schematic diagram of a first perspective of an offshore wind power combination foundation provided in an embodiment of the present application;

[0022] Figure 2 A schematic structural diagram of a second perspective of an offshore wind power combination foundation provided in an embodiment of the present application;

[0023] Figure 3 A schematic diagram of the structure of a single pile foundation in an offshore wind power combined foundation provided in an embodiment of the present application;

[0024] Figure 4 A schematic diagram of the partial cross-sectional structure of the auxiliary screw piles in the offshore wind power combined foundation provided in an embodiment of the present application.

[0025] In the figure: 100, single pile foundation; 101, exposed section; 102, buried section; 103, inverted cone section; 110, platform; 120, connecting pipe; 130, wing; 200, auxiliary screw pile; 210, auxiliary screw pile shell; 220, top plate; 230, jack; 240, ball screw screw; 250, ball screw nut; 260, spiral drilling rod; 261, rotating rod body; 262, spiral blade; 270, auxiliary screw pile base; 280, base pressure transmission rod; 290, pressure plate. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0029] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0030] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0031] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] The features and performance of the offshore wind power combined foundation and the construction method thereof of the present application are further described in detail below in conjunction with the embodiments.

[0034] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the present application provides an offshore wind power combined foundation, which includes a hollow cylindrical single pile foundation 100 and three auxiliary screw piles 200 arranged at intervals along the circumference of the single pile foundation 100; the auxiliary screw pile 200 includes a hollow cylindrical auxiliary screw pile shell 210, a top plate 220 arranged in the auxiliary screw pile shell 210, a driving mechanism for driving the top plate 220 to move axially along the auxiliary screw pile 200, a ball screw 240 with a top pressing against the top plate 220, a ball screw nut 250 arranged on the ball screw 240 through a threaded sleeve, and a spiral drilling rod connected at the top to the bottom of the ball screw 240 260, the bottom of the auger rod 260 extends to the bottom of the auxiliary screw pile housing 210, and a pair of auxiliary screw pile bases 270 arranged opposite to each other for pressing against the ground are provided below each auxiliary screw pile housing 210, and the ball screw nut 250 in the auxiliary screw pile housing 210 is connected to a pair of corresponding auxiliary screw pile bases 270 through base pressure transmission rods 280, respectively. In this embodiment, two pressure plates 290 are connected to the inner wall of the top of the auxiliary screw pile housing 210, and the driving mechanism is two jacks 230, one end of each jack 230 is connected to a pressure plate 290, and the other end is connected to the top plate 220. The auger rod 260 includes a rotating rod body 261 and a spiral blade 262 connected to the outer wall of the rotating rod body 261, and the outer diameter of the spiral blade 262 gradually decreases as it extends downward, and the minimum diameter of the spiral blade 262 is 30 cm.

[0035] The outer wall of the single pile foundation 100 is fixedly sleeved with an annular platform 110, and the top of each auxiliary screw pile shell 210 is connected to the platform 110 through a connecting pipe 120; the single pile foundation 100 includes an exposed section 101, an embedded section 102 and an inverted cone section 103 connected in sequence, and the outer wall of the embedded section 102 of the single pile foundation 100 is connected with three side wings 130 arranged at intervals along its circumference, and the side wings 130 are isosceles trapezoidal plates whose lower bottom edges are connected to the outer wall of the single pile foundation 100, and the length ratio of the upper bottom edge to the lower bottom edge of the side wing 130 is 0.8, the length of the lower bottom edge of the side wing 130 is 1 / 5 of the length of the single pile foundation 100, and the ratio of the height of the side wing 130 to the length of the lower bottom edge is 0.25.

[0036] The present application provides a construction method for an offshore wind power combined foundation, which is carried out using the above-mentioned offshore wind power combined foundation, and comprises the following steps:

[0037] After the installation position is determined, the monopile foundation 100 is driven vertically downward into the ground; a hammering device is used when the monopile foundation 100 is driven vertically downward into the ground. The hammering device can be a hydraulic device, a pneumatic device, an electric drive device, a Moore drive device, etc.

[0038] When the auger drilling rod 260 of each auxiliary screw pile 200 contacts the ground, the control driving mechanism drives the corresponding top plate 220 to move downward along the axial direction of the auxiliary screw pile 200, pushing the auger drilling rod 260 to rotate and move downward along the axial direction of the auxiliary screw pile 200 to drill until the auxiliary screw pile base 270 provided under each auxiliary screw pile shell 210 presses against the ground.

[0039] The offshore wind power combined foundation and its construction method provided in the embodiment of the present application include a single pile foundation 100 and three auxiliary screw piles 200 arranged at intervals along the circumference of the single pile foundation 100; wherein the single pile foundation 100 adopts a hollow cylindrical structure, which saves costs while ensuring structural strength. The single pile foundation 100 includes an exposed section 101, an embedded section 102 and an inverted cone section 103 connected in sequence. The outer diameter of the inverted cone section 103 gradually decreases downward, which can reduce the material used in the single pile foundation 100, reduce manufacturing costs, and reduce the bending moment borne by the embedded section 102 located below the seabed surface, thereby ensuring the structural strength of the single pile foundation 100 while saving costs.

[0040] The outer wall of the embedded section 102 of the single pile foundation 100 is connected to three isosceles trapezoidal wings 130. When the embedded section 102 of the single pile foundation 100 is buried in the foundation soil, the three wings 130 also enter at the same time, so that the larger part of the pressure at the bottom of the trapezoidal oblique side of the wing 130 contacts the soil layer first and is easier to break through the soil layer, and then the straight line parts of the trapezoidal top and bottom of the wing 130 increase the contact surface with the soil layer while reducing the use of materials. After the embedded section 102 of the single pile foundation 100 reaches the specified depth and stabilizes, the three wings 130 bear the stress from the horizontal direction of the soil layer and transfer the horizontal load acting on the wing 130 to the single pile foundation 100, so that the embedded section 102 of the single pile foundation 100 is subjected to greater horizontal stress and improves stability.

[0041] The jack 230 in the auxiliary screw pile 200 serves as a driving mechanism. When the auxiliary screw pile 200 reaches the specified position, the jack 230 receives a control command and starts to apply downward pressure to push the top plate 220 to move downward along the axial direction of the auxiliary screw pile 200. When the top plate 220 moves downward, it pushes the ball screw 240 and the spiral drilling rod 260 connected thereto to move downward along the axial direction of the auxiliary screw pile 200. The ball screw 240 moving downward along the axial direction of the auxiliary screw pile 200 is driven by the thread on the inner wall of the ball screw nut 250 to drive the connected spiral drilling rod 260 to rotate to realize the downward drilling operation, thereby making flexible adjustments to marine environments of different depths and complexities, thereby reducing construction costs and operation and maintenance costs.

[0042] The spiral drilling rod 260 includes a rotating rod body 261 and a spiral blade 262 connected to the outer wall of the rotating rod body 261. The outer diameter of the spiral blade 262 gradually decreases as it extends downward. The minimum diameter of the spiral blade 262 is 30 cm, which makes the spiral drilling rod 260 have the characteristics of large torque and not easy to get stuck. The drilling is more stable and can be more firmly fixed in the soil layer.

[0043] A pair of auxiliary screw pile bases 270 arranged opposite to each other for pressing against the ground are provided below each auxiliary screw pile shell 210. The ball screw nut 250 in the auxiliary screw pile shell 210 is connected to a pair of corresponding auxiliary screw pile bases 270 through a base pressure transmission rod 280. When the single pile foundation 100 is driven vertically downward into the ground so that the auxiliary screw pile base 270 contacts the ground and receives an impact force, the impact force acting on the auxiliary screw pile base 270 is transmitted to the ball screw nut 250 through the base pressure transmission rod 280, thereby transferring the force acting on the foundation, thereby reducing the impact force on the auxiliary screw pile. The pile base 270 and the auxiliary screw pile shell 210 are damaged. At the same time, when the base pressure transmission rod 280 receives the impact force from the auxiliary screw pile base 270, it will apply the impact force to the ball screw nut 250. The ball screw nut 250 will have an upward movement tendency when receiving the upward impact force, giving the ball screw screw 240 an upward movement force. The upward movement tendency generated by the ball screw screw 240 will act on the top plate 220, and the top plate 220 will be blocked by the jack 230, so that it will transfer the force to the jack 230, thereby alleviating the effect of the impact force on the foundation.

[0044] In a further embodiment, a detachable annular platform 110 is provided on the outer wall of the single pile foundation 100, and the top of each auxiliary screw pile shell 210 is connected to the platform 110 via a detachable connecting pipe 120; the platform 110 and the connecting pipe 120 can be removed from the single pile foundation 100, and the single pile foundation 100 and the auxiliary screw piles 200 can also be dismantled for recycling.

[0045] In a further embodiment, the driving mechanism for driving the top plate 220 to move axially along the auxiliary screw pile 200 may also be a hydraulic device, a pneumatic device, an electric drive device, or a Moore drive device.

[0046] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. An offshore wind power combined foundation, characterized in that: The invention relates to a single pile foundation and at least three auxiliary screw piles arranged at intervals along the circumference of the single pile foundation, wherein the auxiliary screw piles are connected to the single pile foundation, and the auxiliary screw piles include an auxiliary screw pile shell, a top plate arranged in the auxiliary screw pile shell, a driving mechanism for driving the top plate to move axially along the auxiliary screw pile, a ball screw rod with a top pressing against the top plate, a ball screw nut threadedly sleeved on the ball screw rod, and an auger rod with a top connected to a bottom of the ball screw rod, wherein the bottom of the auger rod extends below the auxiliary screw pile shell, and at least one auxiliary screw pile base for pressing against the ground is provided below the auxiliary screw pile shell.

2. The offshore wind power combined foundation according to claim 1, characterized in that: The ball screw nut in the auxiliary screw pile housing is connected to the corresponding auxiliary screw pile base through a base pressure transmission rod.

3. The offshore wind power combined foundation according to claim 1, characterized in that: A platform is fixedly sleeved on the single pile foundation, and the top of the auxiliary screw pile shell is connected to the platform through a connecting pipe.

4. The offshore wind power combined foundation according to claim 1, characterized in that: The outer wall of the single pile foundation is connected with a plurality of side wings which are arranged at intervals along the circumference thereof.

5. The offshore wind power combined foundation according to claim 4, characterized in that: The side wing is an isosceles trapezoidal plate whose lower bottom edge is connected to the outer wall of the single pile foundation.

6. The offshore wind power combined foundation according to claim 4, characterized in that: The length ratio of the upper bottom edge to the lower bottom edge of the side wing is 0.8-0.9, the length of the lower bottom edge of the side wing is 1 / 5-1 / 4 of the length of the single pile foundation, and the ratio of the height of the side wing to the length of the lower bottom edge is 0.2-0.

25.

7. The offshore wind power combined foundation according to claim 1, characterized in that: The spiral drilling rod comprises a rotating rod body and a spiral blade connected to the outer wall of the rotating rod body. The outer diameter of the spiral blade gradually decreases as it extends downward, and the minimum diameter of the spiral blade is above 30 cm.

8. The offshore wind power combined foundation according to claim 1, characterized in that: The monopile foundation comprises an exposed section, an embedded section and an inverted cone section which are connected in sequence.

9. The construction method of the offshore wind power combined foundation according to claim 1, characterized in that: The following steps are involved: After the installation position is determined, the single pile foundation is driven vertically downward into the ground; before the single pile foundation is driven vertically downward into the ground, at least one auxiliary screw pile base for pressing against the ground is provided below the auxiliary screw pile shell; When the auger drilling rod of each auxiliary screw pile contacts the ground, the control driving mechanism drives the corresponding top plate to move downward along the axial direction of the auxiliary screw pile, pushes the auger drilling rod to rotate and move downward along the axial direction of the auxiliary screw pile to drill to a predetermined depth.

10. The construction method of offshore wind power combined foundation according to claim 9, characterized in that: The auxiliary screw pile base is connected to the ball screw nut corresponding to the auxiliary screw pile housing.

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