Soft soil area offshore wind power single pile foundation pile sinking reinforcing structure
By using a combination of reinforced sleeve structure and PHC piles in single pile foundations, the problem of insufficient penetration of single pile foundations in weathered rocks in soft soil areas is solved, the bearing capacity and structural frequency of soft soil foundations are improved, the design requirements are met, and environmental damage is reduced.
Patent Information
- Application Number
- CN202420939171.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-30
- Publication Date
- 2025-05-02
- Estimated Expiration
- 2034-04-30
AI Technical Summary
In offshore wind farms in soft soil areas, the penetration degree of single pile foundation in weathered rock is poor, resulting in the pile end failing to reach the predetermined depth, and the pile body is under embedding depth, and the structural frequency is too small, which does not meet the design requirements.
A combination of reinforced sleeve structure and PHC piles is adopted. The inner barrel sleeve is placed outside the single pile foundation, the middle barrel and the outer barrel sleeve are placed outside the inner barrel. The graded gravel compaction layer is filled between the inner barrel and the outer wall of the single pile foundation. PHC piles are drilled between the middle barrel and the outer barrel. The PHC piles penetrate the soft soil layer and enter the lower solid foundation soil.
By strengthening the combination of sleeve structure and PHC piles, the bearing capacity of the soft soil foundation is improved, the penetration degree and structural frequency of the single pile foundation are improved, the design requirements are met, and the damage to the environment is reduced.
Smart Images
Figure CN222822314U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of single pile foundations, in particular to a pile sinking reinforcement structure for offshore wind power single pile foundations in soft soil areas. Background Art
[0002] The monopile foundation has excellent bearing capacity, simple design and manufacturing, and convenient construction. It has been widely used in the built offshore wind farms, especially in the sea areas with small unit capacity and shallow or medium water depth. The monopile foundation is to drive a large diameter steel pipe pile into the seabed, and the upper end of the steel pipe pile is used to fix the supporting tower. In recent years, due to the advancement of construction technology, the monopile foundation has appeared in the form of no transition section, and has gradually developed towards large diameter and large water depth.
[0003] Normally, in order to save investment, the geological drilling hole under the single pile foundation is one hole, and the hole position is located in the center of the foundation. Now the diameter of the single pile foundation is generally 8~10m, and the single hole cannot well represent the soil conditions within the scope of the single pile foundation. If there is weathered rock on the side of the single pile foundation, the penetration degree of the single pile end in the weathered rock is poor, which eventually leads to the pile end failing to reach the predetermined depth. Insufficient pre-buried depth of the single pile body will cause the single pile body to rotate too much, and the structural frequency is too small, which does not meet the design requirements.
[0004] In this case, the soil on the side of the pile can be reinforced. The reinforced foundation includes multiple interlocking piles, which are cement mixing piles and high-pressure rotary jet piles. The projection of the reinforced foundation on the seabed is in a grid shape. The piles in the middle of the reinforced foundation are densely arranged to form a positioning pile structure.
[0005] However, for some sea areas, environmental protection requirements are high, and the use of materials such as cast-in-place cement that damage the environment is not allowed in marine rock and soil. Therefore, other reinforcement structures are needed. Utility Model Content
[0006] The utility model overcomes the shortcomings of the prior art and proposes a pile sinking reinforcement structure for offshore wind power single pile foundation in soft soil areas to solve the problems in the background technology.
[0007] In order to achieve the above purpose, the utility model is implemented through the following technical solutions.
[0008] A pile reinforcement structure for offshore wind power single pile foundation in soft soil area, comprising a reinforcement sleeve structure and PHC piles; the reinforcement sleeve structure comprises an inner layer barrel, a middle layer barrel and an outer layer barrel, the inner layer barrel is sleeved on the outer side of the single pile foundation, and a graded crushed stone compaction layer is filled between the inner wall of the inner layer barrel and the outer wall of the single pile foundation; the middle layer barrel is sleeved on the outer side of the inner layer barrel, and the outer layer barrel is sleeved on the outer side of the middle layer barrel, and a plurality of PHC piles are driven between the inner layer barrel and the middle layer barrel and between the middle layer barrel and the outer layer barrel; the bottom of the PHC pile penetrates the soft soil layer and enters the underlying solid foundation soil; the inner layer barrel, the middle layer barrel and the outer layer barrel are connected into one by a sleeve top beam.
[0009] Furthermore, an inner layer barrel ring beam is arranged at the top of the inner layer barrel; a middle layer barrel ring beam is arranged at the top of the middle layer barrel; an outer layer barrel ring beam is arranged at the top of the outer layer barrel; and the sleeve top beam is connected to the inner layer barrel ring beam, the middle layer barrel ring beam and the outer layer barrel ring beam.
[0010] Furthermore, a plurality of sleeve top beams are connected between the inner sleeve ring beam, the middle sleeve ring beam and the outer sleeve ring beam, and the plurality of sleeve top beams are distributed in a circular array around the center of the single pile foundation.
[0011] Furthermore, a partition barrel is arranged below the sleeve top beam along the height direction; one end of the partition barrel is connected to the outer wall of the inner barrel, the other end is connected to the inner wall of the outer barrel, and the middle is connected to the middle barrel. The PHC piles between the inner barrel and the middle barrel, and between the middle barrel and the outer barrel are evenly divided into multiple intervals through the partition barrel.
[0012] Furthermore, the inner barrel, the middle barrel, the outer barrel, the inner sleeve barrel ring beam, the middle sleeve barrel ring beam, the outer sleeve barrel ring beam, the sleeve top beam, and the partition barrel are welded together into a whole.
[0013] Furthermore, the inner barrel is welded with inner barrel stiffening ribs; the middle barrel is welded with middle barrel stiffening ribs; and the outer barrel is welded with outer barrel stiffening ribs.
[0014] Furthermore, the top of the inner barrel is higher than the top mud surface of the soft soil layer.
[0015] Furthermore, the top of the PHC pile is 0.8-1.2 m higher than the top mud surface of the soft soil layer.
[0016] The beneficial effects of the utility model compared with the prior art are:
[0017] (1) The utility model improves the bearing capacity of soft soil foundation by setting a reinforced sleeve structure, and is more suitable for large-diameter single pile foundation sinking;
[0018] (2) The inner barrel of the reinforced sleeve barrel structure of the utility model and the outer wall of the single pile foundation are compacted with graded crushed stone, which can effectively improve the soft soil structural characteristics between the single pile foundation and the inner barrel of the reinforced sleeve barrel structure, and ensure that the single pile foundation and the inner barrel of the reinforced sleeve barrel structure fit tightly and bear the force together.
[0019] (3) PHC piles are driven into the gaps between the inner, middle and outer barrels of the reinforced sleeve barrel structure of the utility model. The PHC piles can compact the surface soft soil foundation to form a composite foundation. Due to the constraint of the barrel wall, the soil is compacted more densely, which greatly improves the mechanical properties of the surface soft soil. The PHC piles are driven into a deep depth, penetrate the soft soil layer and enter a certain depth into the underlying solid foundation soil. Therefore, the PHC piles have good horizontal and axial bearing capacity. The PHC piles and the sleeve barrel reinforcement structure form a force-bearing whole, which can greatly provide the horizontal stiffness of the single pile.
[0020] (4) The height of the inner barrel of the reinforced sleeve barrel structure of the utility model above the mud surface is set according to the engineering needs. The inner barrel of the reinforced sleeve barrel structure is raised to a certain height above the mud surface, which can reduce the length of the cantilever section of the single pile foundation and improve the frequency of the single pile structure.
[0021] (5) In the utility model, the outer barrel diameter of the reinforced sleeve barrel structure is larger than the diameter of the single pile, and the horizontal soil squeezing stress on the pile side is significantly reduced. Therefore, the soil on the pile side is in the elastic stage, the soil strain on the pile side is small, and the displacement on the pile side is small.
[0022] (6) The utility model adopts a reinforced sleeve barrel structure that is closely attached to the single pile foundation. The structural system composed of the sleeve barrel structure and the PHC pile provides a large bending reaction force for the single pile foundation, which makes the bending moment below the mud surface of the single pile foundation smaller, and can save the amount of steel used in the single pile foundation.
[0023] (7) The utility model does not use poured concrete, which reduces damage to the environment to a minimum, and the foundation can be basically restored to its original state after decommissioning.
[0024] (8) When constructing the structure of the utility model, the operation is simple, the requirements for pile driving machinery are not high, and the structure is reliable in force.
[0025] (9) The PHC pile of the utility model is about 1m above the mud surface, which can effectively form a disturbance around the single pile foundation, reduce the scouring damage to the single pile foundation, and effectively protect the loss of the anti-scouring gravel layer, thereby reducing the scouring protection cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 Schematic diagram of the depth of pile sinking for the single pile foundation;
[0027] Figure 2 It is a side view of the reinforcement sleeve structure;
[0028] Figure 3 A top view of the reinforcement sleeve structure;
[0029] Figure 4 It is a top view of the single pile foundation reinforcement structure;
[0030] Figure 5 This is the elevation view of the single pile foundation reinforcement structure;
[0031] Figure 6 It is the structural schematic diagram of PHC pile;
[0032] In the figure: 1. Inner barrel; 2. Middle barrel; 3. Outer barrel; 4. Single pile foundation; 5. Graded crushed stone compaction layer; 6. PHC pile; 7. Soft soil layer; 8. Lower solid foundation soil; 9. Sleeve top beam; 10. Separation barrel; 11. Inner barrel ring beam; 12. Middle barrel ring beam; 13. Outer barrel ring beam; 14. Inner barrel stiffening ribs; 15. Middle barrel stiffening ribs; 16. Outer barrel stiffening ribs. DETAILED DESCRIPTION
[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail in combination with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The technical solution of the present invention is described in detail below in combination with the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.
[0034] See also Figure 1-Figure 6 The present embodiment discloses a pile reinforcement structure for offshore wind power single pile foundation in soft soil area, including a reinforcement sleeve structure and a PHC pile 6; the reinforcement sleeve structure includes an inner layer barrel 1, a middle layer barrel 2, and an outer layer barrel 3, the inner layer barrel 1 is sleeved on the outside of the single pile foundation 4, and a graded crushed stone compaction layer 5 is filled between the inner wall of the inner layer barrel 1 and the outer wall of the single pile foundation 4; the inner layer barrel 1 and the outer wall of the single pile foundation 4 are compacted with graded crushed stone, which can effectively improve the soft soil structural characteristics between the single pile foundation 4 and the inner layer barrel 1 of the reinforcement sleeve barrel structure, and ensure that the single pile foundation and the inner barrel of the reinforcement sleeve barrel structure are tightly fitted and subjected to force together.
[0035] The middle barrel 2 is sleeved on the outside of the inner barrel 1, and the outer barrel 3 is sleeved on the outside of the middle barrel 2. A plurality of PHC piles 6 are driven between the inner barrel 1 and the middle barrel 2 and between the middle barrel 2 and the outer barrel 3. The bottom of the PHC pile 6 penetrates the soft soil layer 7 and enters the underlying solid foundation soil 8. The top of the PHC pile 6 is 0.8-1.2m higher than the top mud surface of the soft soil layer 7. The plurality of PHC piles 6 are distributed in a circular array with the center of the single pile foundation 4. PHC piles 6 are driven into the gaps between the inner barrel 1, the middle barrel 2, and the outer barrel 3 of the reinforced barrel structure. The PHC piles 6 can compact the surface soft soil foundation to form a composite foundation. Due to the barrel wall constraint, the soil is compacted more densely, greatly improving the mechanical properties of the surface soft soil. The PHC piles 6 are driven into a deep depth, penetrate the soft soil layer 7 and enter the lower solid foundation soil 8 to a certain depth. Therefore, the PHC piles 6 have good horizontal and axial bearing capacity. The PHC piles 6 and the barrel reinforcement structure form a force-bearing whole, which can greatly provide the horizontal stiffness of the single pile. The PHC piles 6 are about 1m higher than the mud surface, which can effectively form a disturbance around the single pile foundation 4, reduce the scouring damage to the single pile foundation 4, and effectively protect the loss of the anti-scouring gravel layer.
[0036] The inner barrel 1 is provided with an inner barrel ring beam 11 on the top; the middle barrel 2 is provided with a middle barrel ring beam 12 on the top; the outer barrel 3 is provided with an outer barrel ring beam 13 on the top; eight sleeve top beams 9 are connected to the inner barrel ring beam 11, the middle barrel ring beam 12, and the outer barrel ring beam 13. The inner barrel 1, the middle barrel 2, and the outer barrel 3 are connected as a whole through the sleeve top beam 9. The eight sleeve top beams 9 are distributed in a circular array with the center of the single pile foundation 4.
[0037] A partition barrel 10 is arranged below the sleeve top beam 9 in the height direction; one end of the partition barrel 10 is connected to the outer wall of the inner barrel 1, the other end is connected to the inner wall of the outer barrel 3, and the middle is connected to the middle barrel 2. The inner barrel 1 and the middle barrel 2, and the middle barrel 2 and the outer barrel 3 are divided into 16 independent spaces by the partition barrel 10, and a plurality of PHC piles 6 are evenly divided into the 16 spaces. The inner barrel 1, the middle barrel 2, the outer barrel 3, the inner barrel ring beam 11, the middle barrel ring beam 12, the outer barrel ring beam 13, the sleeve top beam 9, and the partition barrel 10 are welded together into a whole.
[0038] The inner barrel 1 is welded with a plurality of inner barrel stiffening ribs 14 along the circumference of the barrel wall; the middle barrel 2 is welded with a plurality of middle barrel stiffening ribs 15 along the circumference of the barrel wall; and the outer barrel 3 is welded with a plurality of outer barrel stiffening ribs 16 along the circumference of the barrel wall.
[0039] Furthermore, the top of the inner barrel 1 is higher than the top mud surface of the soft soil layer 7, which can reduce the length of the cantilever section of the single pile foundation 4 and improve the single pile structure frequency.
[0040] The reinforcement sleeve structure in this embodiment has been calculated, and its inner diameter is required to ensure smooth passage through auxiliary structures such as lifting ears; the gap between the reinforcement sleeve structure and the single pile foundation 4 is filled with graded crushed stone and compacted, and the graded crushed stone has the function of compacting soft soil and improving the performance of foundation soil. This step ensures that the reinforcement sleeve structure and the single pile foundation 4 fit closely; since the SPT value of the surface soil of the soft soil foundation is very small, generally only 0-2, the reinforcement sleeve structure can sink by its own weight, and the top beam and ring beam on the top of the sleeve can prevent the sleeve structure from further sinking by its own weight; After the barrel sinks to the designated position, the PHC pile 6 is driven into the gap between the barrels by means of a ship-mounted piling device, and the end of the PHC pile 6 is driven into a hard or dense soil layer. The PHC pile 6 forms a composite foundation with the soft soil foundation, which not only compacts the upper soft soil, but also organically combines the upper soft soil with the lower non-soft soil through the reinforcement effect, thereby greatly improving the undrained shear strength of the soft soil. After the PHC pile 6 is sunk, the pile head is exposed to the ground for about 1m, which can achieve a disturbing effect on the surrounding of the single pile foundation, and the upper anti-scour gravel layer can also be well fixed.
[0041] The above content is a further detailed description of the utility model in combination with a specific preferred implementation method. It cannot be determined that the specific implementation methods of the utility model are limited to this. For ordinary technicians in the technical field to which the utility model belongs, they can make several simple deductions or substitutions without departing from the utility model, which should be regarded as belonging to the utility model and the scope of patent protection determined by the submitted claims.
Claims
1. A pile reinforcement structure for offshore wind power single pile foundation in soft soil areas, characterized in that: The invention comprises a reinforcement sleeve structure and a PHC pile (6); the reinforcement sleeve structure comprises an inner barrel (1), a middle barrel (2), and an outer barrel (3); the inner barrel (1) is sleeved on the outside of a single pile foundation (4); a graded crushed stone compaction layer (5) is filled between the inner wall of the inner barrel (1) and the outer wall of the single pile foundation (4); the middle barrel (2) is sleeved on the outside of the inner barrel (1); the outer barrel (3) is sleeved on the outside of the middle barrel (2); a plurality of PHC piles (6) are driven between the inner barrel (1) and the middle barrel (2) and between the middle barrel (2) and the outer barrel (3); the bottom of the PHC pile (6) penetrates a soft soil layer (7) and enters a lower solid foundation soil (8); the inner barrel (1), the middle barrel (2), and the outer barrel (3) are connected as a whole through a sleeve top beam (9).
2. The soft soil offshore wind power single pile foundation pile reinforcement structure according to claim 1, characterized in that: The inner barrel (1) is provided with an inner sleeve barrel ring beam (11) at the top; the middle barrel (2) is provided with a middle sleeve barrel ring beam (12) at the top; the outer barrel (3) is provided with an outer sleeve barrel ring beam (13) at the top; and the sleeve top beam (9) is connected to the inner sleeve barrel ring beam (11), the middle sleeve barrel ring beam (12), and the outer sleeve barrel ring beam (13).
3. The soft soil offshore wind power single pile foundation pile reinforcement structure according to claim 2, characterized in that: A plurality of sleeve top beams (9) are connected between the inner sleeve ring beam (11), the middle sleeve ring beam (12) and the outer sleeve ring beam (13), and the plurality of sleeve top beams (9) are distributed in a circular array at the center of the single pile foundation (4).
4. The soft soil offshore wind power single pile foundation pile reinforcement structure according to claim 3, characterized in that: A partition barrel (10) is arranged below the sleeve top beam (9) in the height direction; one end of the partition barrel (10) is connected to the outer wall of the inner barrel (1), the other end is connected to the inner wall of the outer barrel (3), and the middle is connected to the middle barrel (2); the PHC piles (6) between the inner barrel (1) and the middle barrel (2), and between the middle barrel (2) and the outer barrel (3) are evenly divided into a plurality of sections through the partition barrel (10).
5. The soft soil offshore wind power single pile foundation pile reinforcement structure according to claim 4, characterized in that: The inner barrel (1), the middle barrel (2), the outer barrel (3), the inner sleeve barrel ring beam (11), the middle sleeve barrel ring beam (12), the outer sleeve barrel ring beam (13), the sleeve top beam (9), and the partition barrel (10) are welded together to form a whole.
6. The soft soil offshore wind power single pile foundation pile reinforcement structure according to claim 1, characterized in that: The inner barrel (1) is welded with inner barrel stiffening ribs (14); the middle barrel (2) is welded with middle barrel stiffening ribs (15); and the outer barrel (3) is welded with outer barrel stiffening ribs (16).
7. The soft soil offshore wind power single pile foundation pile reinforcement structure according to claim 1, characterized in that: The top of the inner barrel (1) is higher than the top mud surface of the soft soil layer (7).
8. The soft soil offshore wind power single pile foundation pile reinforcement structure according to claim 1, characterized in that: The top of the PHC pile (6) is 0.8-1.2 m higher than the top mud surface of the soft soil layer (7).