Ocean mooring pile anchor structure with guide wing plate and construction method

Abstract

The invention discloses an ocean mooring pile anchor structure with guide wing plates and a construction method, and belongs to the technical field of ocean deepwater anchoring foundations. In order to solve the problems that an existing piled anchor system is prone to inclination, low in construction precision and insufficient in long-term anti-scouring capacity in the penetration process, the piled anchor system is characterized in that two groups of orthogonally distributed guide wing plates are symmetrically arranged on the outer side of a piled anchor, so that the penetration resistance is reduced; the wing plates are staggered by 45 degrees along the head and the tail of the pile body, the built-in effect of the two ends of the pile anchor and surrounding soil is enhanced, and vertical penetration of the pile anchor is ensured. The construction method comprises the steps that penetration force is transmitted through the accompanying piles and the piling guide pipes, anchor chain pre-tightening and riprap protection are combined, the pile top burial depth is controlled to be 2-3 m lower than the seabed surface, and the scouring influence is effectively reduced. The structure is made of high-strength corrosion-resistant steel, is convenient to construct, adapts to complex seabed conditions, remarkably improves the pile anchor bearing capacity, perpendicularity and long-term stability, is suitable for a deep sea floating type platform mooring system, reduces the operation and maintenance cost and improves the safety of energy facilities.

Description

Technical Field

[0001] The present invention relates to the technical field of deep - water marine mooring foundations, and particularly relates to a marine mooring pile anchor structure with guide vanes and a construction method therefor. Background Art

[0002] As important components of clean energy, offshore wind power and photovoltaic power generation play a crucial role in promoting the transformation of the energy structure, reducing carbon emissions, and enhancing energy security. Compared with onshore photovoltaics, offshore renewable energy can not only effectively alleviate the problems of tight land resources and long power transmission distances, but also deeply integrate with industries such as marine hydrogen production and fishery farming, forming a diversified development model and showing broad commercial prospects. However, most of the existing offshore wind farms and photovoltaic farms adopt fixed pile foundations. This foundation form performs well in shallow water areas, but its adaptability in deep - sea areas is limited. As the development gradually expands into deeper waters, floating platforms have become the main development direction, and the safety and long - term stability of floating platforms largely depend on their anchoring systems. As the core component of the mooring system, the anchoring system not only has to resist complex environmental loads such as wind, waves, and currents, but also needs to ensure the position stability of the platform during long - term operation, avoiding affecting the power generation efficiency or even endangering the structural safety due to drift or instability.

[0003] In the existing marine mooring technology, the pile - anchor system has been relatively maturely applied under various geological conditions due to its high bearing capacity and wide applicability. However, in practical engineering applications, pile - anchor construction is often affected by factors such as the heterogeneity of seabed soil, cyclic loads caused by waves and tides, and earthquakes, making it difficult to ensure that the pile can penetrate the soil layer completely vertically. Due to the possible existence of hard interlayers, inclined strata, or dense sand layers in the seabed soil layer, the pile is extremely prone to tilting deformation during the penetration process, resulting in insufficient penetration depth or direction deviation, seriously affecting its bearing capacity and long - term stability.

[0004] The existing technical solutions mainly adopt a cylindrical pile - anchor structure and penetrate it by means of dynamic hammering or static ballasting. However, these solutions generally do not fully consider the possible deflection, inclination, etc. of the pile during the penetration process, so there is also a lack of targeted analysis and effective deviation - correction measures, making it difficult to ensure the verticality and design depth of the pile during the construction process, and thus affecting its bearing capacity and long - term stability.

[0005] For a recyclable barbed pile anchor system with a patent application number of "CN 118257256 A", it uses barbed reinforcement bodies. The barbs are deployed through preset openings on the side wall of the pile and inserted into the surrounding soil to improve the anchoring effect. However, this solution requires the pile to have a relatively large diameter to provide sufficient internal space to accommodate the barb deployment mechanism, and at the same time has high requirements for installation accuracy. Especially in the marine environment, underwater precise positioning and installation control are difficult, and the complex hydrodynamic environment further increases the construction difficulty. In addition, the deployment process of the barbs may cause additional seabed disturbance, loosening the structure of the surrounding soil, affecting the overall anchoring stability, and increasing the complexity of subsequent structure recovery.

[0006] For a pile anchor foundation structure and its installation method for deep - sea environment with a patent application number of "CN 112832282 A", a pile locking device is proposed, which can limit the deflection of a single pile to a certain extent. However, this device mainly acts on a single pile and cannot effectively coordinate the overall verticality control of a multi - pile foundation system. When the anchoring system involves multiple pile anchors, the locking of a single pile cannot ensure the stability of the overall structure. Especially under the action of complex environmental loads such as waves, tides, and earthquakes, it may cause uneven forces on different pile anchors, thus affecting the safety and durability of the entire mooring system.

[0007] In summary, while the existing technologies improve the bearing capacity of pile anchors, there are still the following deficiencies: (1) Insufficient consideration of the control of pile deflection and inclination during the penetration process, lacking effective treatment measures; (2) Some reinforcement measures rely on special structures or complex installation processes, making it difficult to adapt to underwater precise construction and maintenance in the marine environment; (3) Insufficient control of the overall verticality of multi - pile foundations, making it difficult to ensure long - term stability in complex marine environments.

[0008] Therefore, there is an urgent need to optimize the design of pile anchor structures, develop innovative pile anchor systems with high bearing capacity, construction convenience, and environmental adaptability, in order to reduce seabed disturbance, improve construction efficiency, and ensure the long - term stable operation of floating platforms. Summary of the Invention

[0009] The present invention provides a novel pile anchor structure with guiding wing plates and its construction method, which is particularly suitable for the mooring system anchoring foundation of newly built offshore floating structures. The purpose of this invention is to significantly improve the installation verticality and overall bearing capacity of the pile anchor foundation, while effectively reducing the economic cost and construction difficulty.

[0010] To achieve the above - mentioned purpose, the present invention is realized through the following technical solutions:

[0011] An offshore mooring pile anchor structure with guide vanes, comprising a mooring system pile anchor and vane assemblies. Two groups of vane assemblies are symmetrically welded outside the mooring system pile anchor, and each group includes four vane units, which are evenly arranged at intervals of 90° along the axis of the pile anchor.

[0012] Further, the two groups of vane assemblies are respectively arranged at the head and tail of the pile anchor, and their relative positions are staggered by 45° along the axis direction of the pile anchor. This layout design can effectively enhance the anchoring effect of both ends of the pile anchor with the surrounding soil, improve the uplift and anti-overturning capabilities of the pile anchor, and at the same time can significantly reduce the inclination offset of the pile body during the installation process, improving the construction accuracy and stability.

[0013] Further, a through connection hole is designed at the top of the mooring system pile anchor for installing the anchor chain of the mooring system.

[0014] Further, the pile anchor is a hollow steel pipe pile, serving as the main body of the anchoring structure. Its bottom wall thickness is relatively thin, which helps with penetration construction; the top is the hammering part for installation, and the wall thickness is increased by welding a larger-diameter steel pipe on the outside of the pile body to enhance the anti-impact ability.

[0015] Further, the vane is a wedge-shaped thin plate structure, and the wedge angle value needs to be less than 45° - φ / 2, where φ is the internal friction angle of the soil, so as to reduce the penetration resistance of the vane and improve the penetration stability.

[0016] Further, the pile anchor structure with guide vanes can be further expanded. The specific solution is to install multiple layers of vane units along the steel pipe pile and allow a certain relative rotation angle to adapt to different geological conditions and improve the construction adaptability.

[0017] A construction device for installing an offshore mooring pile anchor, comprising: a companion pile, a fixture, and a pile driving conduit. The companion pile is detachably fixed to the top of the mooring system pile anchor through the fixture; the pile driving conduit is clamped on the top of the companion pile, making its top end higher than the sea level for pile driving operations.

[0018] A construction method for installing an offshore mooring pile anchor specifically includes the following steps:

[0019] S1: At a position above the sea level, pass the mooring anchor chain through the connection hole and fix it to the pile anchor. At the same time, the companion pile on the installation ship is fixed to the top of the pile anchor steel pipe through the fixture to form an initial stable structure, ensuring the alignment accuracy during hoisting and penetration, and improving the construction reliability.

[0020] S2: Use the hoisting system to lift and transport the pile anchor structure to the predetermined sea area, and slowly lower it until the bottom of the pile touches the seabed. Subsequently, apply an initial pressure to the top of the pile anchor through the pile driving conduit, causing part of the anchor structure to penetrate into the soil. At this time, the two groups of guiding wing plates gradually penetrate into the soil layer, and effectively suppress the lateral displacement and inclination of the pile body through their orthogonal distribution characteristics, ensuring that the pile body is in a vertical installation posture.

[0021] S3: The pile anchor penetration system on the installation ship uses a pile hammer to repeatedly hammer the pile driving conduit, enabling the penetration force to be effectively transmitted to the accompanying pile and driving the pile anchor structure to continuously sink to the seabed. Due to the restrictive effect of the two groups of guiding wing plates, the pile anchor can penetrate stably in the vertical direction, maintaining the verticality of the pile body to the greatest extent and avoiding the influence of inclination on the bearing capacity. The penetration depth needs to be strictly controlled to ensure that the top of the pile anchor is at least 2 - 3 meters below the seabed surface to reduce the influence of long-term seabed scouring and improve the structural durability. During the penetration process, the anchor chain is always connected to the top of the pile anchor, and the traction equipment on the installation ship maintains an appropriate tension to prevent large displacements of the pile body and improve stability.

[0022] S4: After the pile anchor penetration is completed, retract the accompanying pile and the pile driving conduit. At the same time, use the winch on the installation ship to tighten the anchor chain to make it reach an appropriate pre-tightened state. The anchor chain is connected to the anchor buoy to ensure the smooth docking of the subsequent mooring system. Implement stone pitching protection on the seabed surface near the anchor chain to reduce seabed scouring and improve long-term stability. After all installation procedures are completed, the installation ship withdraws, and the pile anchor installation operation ends.

[0023] Due to the adoption of the above technical solutions, the present invention has the following beneficial effects compared with the prior art:

[0024] Aiming at the problems in the prior art that the pile anchor structure is prone to inclination during the penetration process, the construction accuracy is limited, and the long-term anti-scouring ability is insufficient, the present invention innovatively introduces a pile anchor structure with guiding wing plates and optimizes the penetration control strategy. During the construction process, on the premise of ensuring the vertical initial penetration positioning, two groups of guiding wing plates orthogonally distributed and staggered by 45° at both ends of the pile body effectively suppress the lateral displacement and inclination of the pile body during the penetration process by increasing the anchoring effect with the surrounding soil, ensuring that the pile anchor maintains a vertical posture, thereby significantly improving the penetration accuracy and stability. The design value of the wedge angle of the wing plate is less than the active earth pressure failure angle of the seabed soil, thereby reducing the soil penetration resistance of the wing plate and improving the penetration efficiency and stability.

[0025] The present invention adopts a penetration system combined with an accompanying pile and a pile driving conduit, which can efficiently transmit the hammering energy, enable the pile anchor to smoothly penetrate into the seabed, and ensure that the penetration depth meets the design requirements. After the penetration is completed, through precise buried depth control (ensuring that the top of the pile anchor is at least 2 - 3 meters below the seabed surface) and stone pitching protection measures, the influence of long-term seabed scouring is effectively reduced, and the anti-scouring ability and long-term service stability of the mooring system are significantly improved.

[0026] The structural design of the present invention makes the pile - anchor bearing capacity linearly related to the areas of the pile surface and the guiding wing plates, optimizing the force calculation method and making the design more intuitive and reliable. In addition, the optimized installation method not only improves the structural bearing capacity but also reduces the construction difficulty and project cost, especially suitable for the mooring systems of floating photovoltaic and wind power platforms in complex seabed environments. Compared with the traditional pile - anchor scheme, the present invention has significant technical advantages in aspects such as penetration stability, construction convenience, long - term service reliability, and anti - scouring ability, providing an efficient, safe, and economical anchoring solution for marine mooring engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the present invention, the following will briefly introduce the drawings required for use in the description of the specific embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0028] Figure 1 It is a schematic structural diagram of the pile - anchor device with guiding wing plates of the present invention;

[0029] Figure 2 It is a schematic structural diagram of the wing plate unit in the guiding wing plate assembly of the present invention;

[0030] Figure 3 It is a schematic construction diagram of installing the marine mooring pile - anchor of the present invention;

[0031] Figure 4 It is a layout schematic diagram of the riprap protection net after the pile - anchor penetration of the present invention.

[0032] Among them Figure 3 The corresponding relationship between the reference numerals in the drawings and the components is as follows:

[0033] 1, mooring system anchor pile; 2, wing plate assembly; 3, anchor chain connection hole; 4, anchor chain; 5, companion pile; 6, clamp; 7, driving pile conduit; 8, pile driving hammer; 9, winch; 10, pile - anchor installation ship; 11, riprap protection net; 12, wing plate unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0035] Aiming at the problems that the pile - anchor structure in the prior art is prone to tilt during the penetration process, the construction accuracy is limited, and the long - term anti - scouring ability is insufficient, the present invention proposes an offshore mooring pile - anchor structure with guiding wing plates. This structure aims to ensure that the pile - anchor maintains a vertical posture in the marine environment, thereby significantly improving the penetration accuracy and stability, while reducing the construction difficulty and economic cost.

[0036] Please refer to Figure 1 , in an embodiment of the present invention, the pile - anchor device with guiding wing plates includes the following key components: mooring system pile - anchor 1, wing - plate assembly 2, anchor chain connection hole 3, and anchor chain 4.

[0037] Please refer to Figure 1 , Figure 2 , in the installation preparation stage, the anchor chain 4 is fixed to the top of the mooring system pile - anchor 1 through the connection hole 3, and the other end of the anchor chain 4 is connected to the installation vessel deck or anchor buoy for subsequent docking with the floating structural unit. The pile - anchor 1 uses a hollow steel pipe pile for ocean engineering, and the common pipe diameter range is 500 - 1500 mm (such as 500 mm, 800 mm, 1200 mm, 1500 mm, and interval values between any two end - point values); the wall thickness range is 10 - 50 mm (such as 10 mm, 30 mm, 50 mm, and interval values between any two end - point values). The specific pipe diameter and wall thickness need to be determined through numerical simulation analysis in combination with the seabed soil characteristics, designed penetration depth, and bearing capacity requirements.

[0038] The guiding wing - plate unit 12 is a wedge - shaped steel plate, and its wedge angle is 15° - 30° (such as 15°, 20°, 25°, 30°, and interval values between any two end - point values), and the steel plate thickness is 15 - 30 mm (such as 15 mm, 20 mm, 25 mm, 30 mm, and interval values between any two end - point values). The length of the guiding wing - plate assembly 2 is about 1.5 - 2 times the pipe diameter, and the width is 0.5 - 1 times the pipe diameter. The specific dimensions can be optimized according to the actual engineering requirements.

[0039] The present invention further proposes a construction method applicable to the above - mentioned pile - anchor device with guiding wing plates, aiming to improve the installation efficiency, bearing capacity, and long - term stability of the pile - anchor. This method includes the following steps:

[0040] Step S1: On the pile-anchor installation vessel 10, use the fixture 6 to fix the accompanying pile 5 on the top of the steel pipe of the pile-anchor 1 to form an initial stable structure. Use the hoisting system to hoist the accompanying pile 5 and the pile-anchor with guide wings as a whole to the seabed surface of the designated sea area, ensuring that the pile-anchor 1 of the mooring system remains in a vertical posture. Then, clamp the pile driving conduit 7 on the top of the accompanying pile 5. The length of the pile driving conduit 7 should ensure that its top is always above the sea level throughout the installation process for pile driving operations. The preliminary estimation formula for the length of the pile driving conduit 7 is: the penetration depth of the mooring system anchor pile 1 + the water depth of the sea area - the length of the mooring system anchor pile 1 - the length of the accompanying pile 5.

[0041] Step S2: Start pre-piling. Lift the pile hammer 8 and hammer the top of the pile driving conduit 7 3 - 5 times to make the penetration system settle by 1.5 - 2 times the length of the anchor pile. At this time, the two groups of guide wing plate assemblies 2 gradually penetrate into the soil layer, and effectively suppress the lateral displacement and inclination of the mooring system anchor pile 1 through their orthogonal distribution characteristics, ensuring that the mooring system anchor pile 1 maintains a vertical installation posture (as Figure 3 shown).

[0042] Step S3: Lift the pile hammer 8 to the designed height and continuously hammer the pile driving conduit 7 (generally 30 - 50 times, and the specific number of times is adjusted according to the seabed soil properties) until the pile-anchor system penetrates to the predetermined depth. This depth should ensure that the top of the mooring system anchor pile 1 is at least 2 - 3 meters below the seabed surface to reduce the risk of seabed scouring and ensure meeting the requirements of the designed bearing layer depth.

[0043] Step S4: After the pile-anchor penetration is completed, retract the accompanying pile 5, the fixture 6 and the pile driving conduit 7. At the same time, use the winch 9 on the pile-anchor installation vessel 10 to tighten the anchor chain 4 to make it reach an appropriate pre-tightened state. Connect the anchor chain 4 to the anchor buoy to ensure the smooth docking of the subsequent mooring system. According to the needs of the on-site ocean current environment, it can be decided whether to carry out scour protection. If protection is required, rock dumping protection can be implemented on the seabed surface adjacent to the anchor chain 4. It is recommended that the radius of the rock dumping protection net 11 is 5 - 8 times the pile-anchor pipe diameter and the thickness is 1 - 1.5 times the pipe diameter. After all the installation procedures are completed, the pile-anchor installation vessel 10 withdraws, and the pile-anchor installation operation ends.

[0044] The pile-anchor device with guide wing plates and the construction method of the present invention fully combine the mature construction techniques in the marine engineering field, support the onshore prefabrication and integrated installation of the support device by sea lifting, not only greatly shorten the construction period, reduce the project cost, but also significantly improve the construction efficiency and environmental adaptability.

[0045] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. An ocean mooring pile anchor structure with guiding wing plates, characterized in that, Including: The mooring system pile anchor (1) and the wing plate assembly (2), there are two groups of wing plate assemblies (2) arranged outside the mooring system pile anchor (1), each group includes four wing plate units, and they are evenly arranged along the axis of the pile anchor.

2. The marine mooring pile anchor structure with a guiding vane as described in claim 1, characterized in that The top of the mooring system pile anchor (1) is designed with a through connection hole (3) for installing the anchor chain (4) of the mooring system.

3. The marine mooring pile anchor structure with a guiding wing plate as described in claim 1, wherein The mooring system pile anchor (1) is a hollow steel pipe pile, serving as the main body of the anchoring structure. Its top is the installation and hammering part, and larger-diameter steel pipes are arranged on the outside of the pile body to increase the wall thickness.

4. The marine mooring pile anchor structure with guide vanes as described in claim 1, characterized in that, The two groups of wing plate assemblies (2) are respectively arranged at the head and tail of the pile anchor, and the relative positions of the wing plate units in the wing plate assembly (2) are staggered along the axis of the pile anchor.

5. The marine mooring pile anchor structure with guide vanes according to claim 1, characterized in that, The wing plate assembly (2) is a wedge-shaped thin plate, and the value of the wedge angle is less than wherein is the angle of internal friction of the soil.

6. A construction device for installing marine mooring pile anchors, characterized in that, For installing the marine mooring pile anchor structure with guiding wing plates as described in claims 1 - 5, including: the accompanying pile (5), the fixture (6) and the pile driving conduit (7). The accompanying pile (5) is detachably fixed to the top of the mooring system pile anchor (1) through the fixture (6); the pile driving conduit (7) is clamped on the top of the accompanying pile (5) to make its top higher than the sea level for pile driving operations.

7. The construction device for installing the ocean mooring pile anchor according to claim 6, characterized in that, The length of the pile driving conduit (7) satisfies: the length of the pile driving conduit (7) = the penetration depth of the mooring system anchor pile (1) + the sea depth of the sea area - the length of the mooring system anchor pile (1) - the length of the accompanying pile (5).

8. A construction method for installing an offshore mooring pile anchor, characterized in that, For installing the marine mooring pile anchor structure with guiding wing plates as described in claims 1 - 5, including the following steps: S1: On the installation ship, pass the mooring anchor chain (4) through the anchor chain connection hole (3) and fix it, and fix the accompanying pile (5) to the top of the mooring system pile anchor (1) through the fixture (6); S2: Lift the mooring system pile anchor (1) to the seabed surface of the designated sea area, and after lowering it to the seabed, apply pressure through the pile driving conduit (7) to make the mooring system pile anchor (1) gradually penetrate into the soil layer; S3: Continuously hammer the pile driving conduit (7) using a hammering device to vertically penetrate the mooring system pile anchor (1) into the seabed until the top of the mooring system pile anchor (1) is 2 - 3 meters below the seabed surface; S4: Recover the accompanying pile (5), the fixture (6) and the pile driving conduit (7), tighten the anchor chain (4) to the pre-tightened state, and implement riprap protection on the seabed near the anchor chain (4).

9. The construction method for installing an offshore mooring pile anchor according to claim 8, characterized in that, In step S4, the covering radius of the riprap protection is 5 - 8 times the pipe diameter of the pile anchor, and the thickness is 1 - 1.5 times the pipe diameter.

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