Marine mooring pile anchor and construction structure and construction method thereof

Abstract

The invention discloses an ocean mooring pile anchor and a construction structure and a construction method thereof, the ocean mooring pile anchor comprises a pile anchor main body, the pile anchor main body is tubular, and fins are arranged on the outer side wall of the pile anchor main body; the umbrella cap is a thin-wall shell, the appearance of the umbrella cap is in an inverted circular truncated cone shape, the cross section of the umbrella cap shrinks linearly in the axial direction, the whole umbrella cap is of a big-end-up conical curved surface structure, the umbrella cap is fixedly arranged at one end of the pile anchor body, the circular-truncated-cone-shaped large-area end face of the umbrella cap faces the pile anchor body, and the outer diameter of the fins is smaller than the diameter of the circular-truncated-cone-shaped large-area end of the umbrella cap. The ocean mooring pile anchor construction method is used for installing the ocean mooring pile anchor through the ocean mooring pile anchor construction structure and comprises the steps that S1, preparation work is conducted, S2, hoisting work is conducted, S3, piling work is conducted, and S4, the accompanying pile, the guide pipe and the jetting device are taken back in sequence, and the anchor chain is tightened through the winch.

Description

Technical Field

[0001] This field relates to the field of offshore wind power and photovoltaic technology, and particularly relates to an offshore mooring pile anchor and its construction structure and construction method. Background Art

[0002] As an important part of clean energy, offshore photovoltaic power generation plays a key role in promoting the transformation of the energy structure, reducing carbon emissions and enhancing energy security. Compared with onshore photovoltaics, offshore photovoltaics make full use of sea area resources, alleviate the tension of land resources, and at the same time can be deeply integrated with industries such as offshore wind power, hydrogen production, and fisheries to form a synergistic energy system. However, at present, most offshore photovoltaic farms still use fixed pile foundations, which are suitable for shallow water areas, but their adaptability is limited in deep water areas or complex seabed environments. Therefore, floating photovoltaic platforms and their supporting mooring systems have become an important direction for photovoltaic development in deep water areas, and the anchoring system is one of the key technologies to ensure the long-term safe operation of floating photovoltaic platforms. Floating photovoltaic platforms are in complex marine environments such as wind, waves and currents for a long time. Their anchoring systems not only need to have sufficient anti-pulling, anti-overturning and anti-sliding capabilities, but also need to maintain stability during long-term service to prevent platform drift, collision or failure.

[0003] In the existing technical solutions, the installation of screw piles mainly relies on a rotary device to provide torque drive to achieve the spiral penetration of the pile body into the seabed. However, in complex marine environments, especially under deep-sea conditions, the existing technology still faces many challenges during the installation process. In some technical solutions, although the screw pile foundation structure improves the penetration ability of the pile body through screw blades, in hard strata or high-density soil layers, the torque requirement is too large, and the existing rotary devices are difficult to provide sufficient driving force, resulting in limited construction. In addition, in the deep-sea environment, due to the limitation of installation equipment caused by the increase in water depth, the traditional torque transmission method may affect the construction efficiency due to energy loss and shaft system torsional deformation, making it difficult for the screw pile to reach the target depth smoothly. On the other hand, during the long-term service of screw piles, their durability is still affected by the harsh marine environment. Especially under the action of strong ocean currents and alternating loads, the fatigue damage and corrosion problems of the pile body are relatively prominent. There are also some screw pile foundation structures that, although they improve the bearing capacity through optimized blade design, their pile body materials may experience fatigue cracking under long-term seawater erosion and dynamic loads, affecting the overall stability of the structure. Especially in the deep-sea environment, there is a large uncertainty in the interaction between the screw blades and the surrounding soil, and local instability may occur during long-term service due to changes in seabed sediments. In addition, seawater corrosion and marine organism attachment may further reduce the durability of the pile body surface, increasing the difficulty of later maintenance and repair. At the same time, the adaptability of existing screw piles in extreme marine environments still needs to be improved. For example, in deep-sea soft soil strata or complex geological environments, the bearing capacity distribution of traditional screw blades may be uneven, resulting in reduced pile body stability. Summary of the Invention

[0004] The object of the present invention is to provide an offshore mooring pile anchor and its construction structure and construction method. The specific technical solutions are as follows: An offshore mooring pile anchor, comprising: a pile anchor main body, the pile anchor main body is set as a tubular shape, and finned plates are arranged on the outer side wall of the pile anchor main body; a canopy, the canopy is a thin-walled shell, the outer shape of the canopy is an inverted frustum of a cone, the cross-section of the canopy shrinks linearly along the axial direction, and the whole is a conical curved surface structure with a large upper part and a small lower part. The canopy is fixedly arranged at one end of the pile anchor main body, and the large-area frustum-shaped end surface of the canopy faces the pile anchor main body, and the outer diameter of the finned plates is smaller than the diameter of the large-area frustum-shaped end of the canopy.

[0005] The canopy is sleeved on the pile anchor main body, the diameter of the small-area top end of the frustum of the canopy is equal to the diameter of the pile anchor main body, and the bottom of the frustum of the canopy is fixedly connected to the pile anchor main body through a rib plate.

[0006] The pile anchor main body is set as a hollow steel pipe, and an installation sleeve is fixedly arranged at the end of the pile anchor main body facing away from the canopy. The installation sleeve is sleeved on the pile anchor main body and is used to increase the wall thickness of this end of the pile anchor main body.

[0007] A connection hole is arranged at the end of the pile anchor main body facing away from the canopy, and the connection hole is used for installing an anchor chain.

[0008] The fins are arranged as single - loop spiral blades evenly distributed on the outer side wall of the pile - anchor main body or a single spiral blade is continuously wound around the outer side wall of the pile - anchor main body for multiple turns.

[0009] A marine mooring pile - anchor construction structure for installing the above - mentioned marine mooring pile - anchor, comprising: a pile - anchor installation ship for transporting and carrying installation equipment; an accompanying pile installed at one end of the pile - anchor main body opposite to the umbrella cap for providing an initial stable structure for the installation of the pile - anchor; a guide pipe clamped at one end of the accompanying pile opposite to the pile - anchor main body, and the guide pipe is higher than the sea level after installation; a hammering device arranged on the pile - anchor installation ship, the hammering device includes a winch and a pile hammer, and the winch is used to control the pile hammer to hammer one end of the guide pipe exposed above the sea level. It further includes: a jetting device, the jetting device includes a jetting pipe and a high - pressure water pump, jetting holes are arranged on the side wall of the umbrella cap, the high - pressure water pump is arranged on the pile - anchor installation ship, one end of the jetting pipe is inserted into the jetting hole, and the other end of the jetting pipe is connected to the high - pressure water pump for jetting high - pressure water during installation to reduce the penetration resistance and improve the soil disturbance characteristics.

[0010] A marine mooring pile - anchor construction method for installing the above - mentioned marine mooring pile - anchor by using the above - mentioned marine mooring pile - anchor construction structure, comprising: S1. Conduct preparatory work, start the facilities, install the anchor chain, install the accompanying pile at one end of the pile - anchor main body opposite to the umbrella cap, and install the jetting pipe on the outer side wall of the pile - anchor main body and insert one end into the jetting hole; S2. Conduct hoisting operations, use hoisting equipment to hoist the pile - anchor main body with the installed accompanying pile to a preset position and maintain a vertical posture with the umbrella cap facing downwards, and install the guide pipe; S3. Conduct pile - driving operations, start the high - pressure water pump, jet high - pressure water to the bottom of the pile - anchor main body to destroy the soil structure at the pile end and promote local soil liquefaction. At this time, control the hammering device to conduct continuous hammering until the pile - anchor system penetrates to a predetermined depth; S4. Withdraw the accompanying pile, the guide pipe and the jetting device in sequence, and at the same time, use the winch to tighten the anchor chain. Before conducting the pile - driving operation in S3, pre - drive the pile first, control the hammering device to hammer one end of the guide pipe exposed above the sea level until the settlement is 1.2 - 2.5 times the length of the pile - anchor main body. After completing step S4, conduct stone - throwing protection, the protection radius is 5 - 8 times the diameter of the pile - anchor main body, and the protection thickness is 1 - 1.5 times the diameter of the pile - anchor main body.

[0011] The above technical solution of the present invention has the following beneficial technical effects: Aiming at the problems in the prior art that the helical pile anchor structure is easily affected by the characteristics of seabed soil during the penetration process, resulting in limited construction accuracy, low penetration efficiency, and insufficient long-term stability and anti-scour ability, the present invention innovatively introduces a combined design of an umbrella cap structure and helical blades, and combines a penetration control strategy with the synergistic action of high-pressure water jet and pile hammer power to optimize the force distribution and dynamic transmission mechanism during the penetration process. During the construction process, the high-pressure water jet system can effectively break the soil structure at the pile tip, reduce the penetration resistance, and cooperate with the precise control of the driving pipe to ensure that the pile anchor maintains a vertical posture, improving the penetration accuracy and construction stability. By optimizing the burial depth control (ensuring that the top of the pile anchor is at least 2-3 meters below the seabed surface) and the riprap protection measures, the long-term seabed scouring effect is significantly reduced, and the anti-scour ability and long-term service stability of the mooring system are enhanced. Compared with the traditional pile anchor scheme, the present invention shows significant technical advantages in terms of penetration stability, construction convenience, structural bearing capacity, and long-term anti-scour performance, providing an efficient, safe, and economical anchoring solution for the mooring systems of floating photovoltaic and wind power platforms in complex seabed environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram of the marine mooring pile anchor structure in this application; Figure 2 Schematic diagram of the structure when installing the marine mooring pile anchor in this application; Wherein: 1 - pile anchor main body, 2 - fin, 3 - umbrella cap, 4 - connection hole, 5 - jet pipe, 6 - companion pile, 7 - pipe, 8 - anchor chain, 9 - pile anchor installation ship, 10 - high-pressure water pump, 11 - winch, 12 - pile hammer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0014] An offshore mooring pile anchor, comprising: a pile anchor body 1, the pile anchor body 1 is arranged in a tubular shape, and fins 2 are arranged on the outer side wall of the pile anchor body 1; a canopy 3, the canopy 3 is arranged in a frustum shape, and the small-area end of the frustum shape of the canopy 3 is fixedly arranged at one end of the pile anchor body 1, and the outer diameter of the fin 2 is smaller than the bottom diameter of the large end of the frustum shape of the canopy 3. In actual use, the pile anchor body 1 adopts 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 the interval values between any two end points); the wall thickness range is 10~50 mm (such as 10 mm, 30 mm, 50 mm and the interval values between any two end points). The specific pipe diameter and wall thickness need to be determined through numerical simulation analysis in combination with the characteristics of the seabed soil, the designed penetration depth and the bearing capacity requirements. The fin 2 is set as a cold-rolled steel plate blade, the coil height is 1~1.5 times the pipe diameter of the pile anchor body 1, the inner and outer radii are 1 time and 2 times the radius of the pile anchor body 1 respectively, and it rotates 180° counterclockwise. Multiple blades are evenly distributed along the axial direction of the pile body and fixed on the pile body. The spiral blade can also be designed as a continuous blade, and the specific dimensions can be optimized according to the actual engineering requirements.

[0015] The canopy 3 is sleeved on the pile anchor body 1, the diameter of the small-area end of the top of the frustum shape of the canopy 3 is equal to the diameter of the pile anchor body 1, and the bottom of the frustum shape of the canopy 3 is fixedly connected to the pile anchor body 1 through a rib plate. The canopy 3 is fixedly welded to the end of the pile anchor body 1; the radius of the large-area end of the bottom of the frustum shape of the canopy 3 is 2~2.5 times the radius of the pile anchor body 1. Multiple rib plates are evenly arranged inside the canopy 3, generally 4~8 pieces, and are fixedly connected to the pile body to enhance the structural strength. The included angle between the canopy 3 and the pile anchor body 1 needs to be less than 45°-φ / 2 (φ is the soil internal friction angle) to reduce the soil penetration resistance and improve the penetration stability.

[0016] The pile anchor body 1 is arranged as a hollow steel pipe, and an installation sleeve is fixedly arranged at one end of the pile anchor body 1 facing away from the canopy 3. The installation sleeve is sleeved on the pile anchor body 1 to increase the wall thickness at this end of the pile anchor body 1.

[0017] A connection hole 4 is arranged at one end of the pile anchor body 1 facing away from the canopy 3, and the connection hole 4 is used for installing the anchor chain 8.

[0018] The fin 2 is arranged as multiple single-turn spiral blades evenly distributed on the outer side wall of the pile anchor body 1 or a single spiral blade is continuously wound around the outer side wall of the pile anchor body 1 for multiple turns.

[0019] An offshore mooring pile anchor construction structure for installing the above-mentioned offshore mooring pile anchor, comprising: a pile anchor installation ship 9 for transporting and carrying installation equipment; an accompanying pile 6 installed at one end of the pile anchor body 1 opposite to the umbrella cap 3 for providing an initial stable structure for the installation of the pile anchor; a guide pipe 7 clamped at one end of the accompanying pile 6 opposite to the pile anchor body 1, and the guide pipe 7 is installed above the sea level after installation; a hammering device arranged on the pile anchor installation ship 9, the hammering device includes a winch 11 and a pile hammer 12, and the winch 11 is used to control the pile hammer 12 to hammer one end of the guide pipe 7 exposed above the sea level. It further includes: a jetting device, the jetting device includes a jetting pipe 5 and a high-pressure water pump 10, jetting holes are provided on the side wall of the umbrella cap 3, the high-pressure water pump 10 is arranged on the pile anchor installation ship 9, one end of the jetting pipe 5 is inserted into the jetting hole, and the other end of the jetting pipe 5 is connected to the high-pressure water pump 10 for jetting high-pressure water during installation to reduce the penetration resistance and improve the soil disturbance characteristics. In actual use, the jetting pipe 5 is a hollow steel pipe, the outer diameter can generally be taken as 30 - 50 mm (such as 30 mm, 40 mm, 50 mm and the interval values between any two end points), and the wall thickness is 2 - 5 mm (such as 2 mm, 3 mm, 4 mm, 5 mm and the interval values between any two end points). The jetting pipe 5 is installed on the outer side wall of the pile anchor body 1, the bottom penetrates through the structure of the umbrella cap 3 to contact the seabed, and the other end is connected to the high-pressure water pump 10 on the installation ship. The high-pressure water is directly jetted to the bottom of the pile anchor body 1 to reduce the penetration resistance and improve the soil disturbance characteristics.

[0020] An offshore mooring pile anchor construction method for installing the above-mentioned offshore mooring pile anchor by using the above-mentioned offshore mooring pile anchor construction structure, comprising: S1. Conduct preparatory work, start the facilities, install the anchor chain 8, install the accompanying pile 6 at one end of the pile anchor body 1 opposite to the umbrella cap 3, and install the jetting pipe 5 on the outer side wall of the pile anchor body 1 and insert one end into the jetting hole.

[0021] S2. Conduct hoisting operations, use hoisting equipment to hoist the pile anchor body 1 with the accompanying pile 6 installed to the preset position and maintain the vertical posture with the umbrella cap 3 downward, and install the guide pipe 7. Use the hoisting system to hoist the accompanying pile 6 and the pile anchor 1 as a whole to the seabed surface of the designated sea area to ensure that the pile anchor maintains a vertical posture. Then, clamp the driving pile guide pipe 7 on the top of the accompanying pile 6, and the length of the guide pipe 7 needs to ensure that its top end is always above the sea level throughout the installation process for driving pile operations. The preliminary estimation formula for the length of the guide pipe 7 is: the penetration depth of the anchor pile + the water depth of the sea area - the length of the anchor pile - the length of the accompanying pile 6.

[0022] S3. Start pre-driving the pile. Use the pile hammer 12 to hammer the top of the pile driving conduit 7 3 - 5 times, causing the penetration system to settle by 1.5 - 2 times the length of the anchor pile. During this process, the umbrella cap 3 and the fins 2 gradually penetrate into the soil layer. In this step, special attention needs to be paid to keeping the pile body vertically installed at all times to ensure the construction accuracy. Conduct the pile driving operation. Start the high-pressure water pump 10 and spray high-pressure water to the bottom of the pile anchor body 1 to destroy the soil structure at the pile tip and promote local liquefaction of the soil layer. At this time, control the hammering device to conduct continuous hammering until the pile anchor system penetrates to the predetermined depth. The water pressure can be controlled between 0.5 - 1.0 MPa (such as 0.5 MPa, 0.7 MPa, 1.0 MPa, and the interval values between any two endpoint values). At this time, lift the pile hammer 12 to the designed height and conduct continuous hammering on the pile driving conduit 7 (usually 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. The penetration depth needs to ensure that the top of the pile anchor is 2 - 3 meters below the seabed surface to reduce the scouring risk and ensure meeting the requirements of the designed bearing layer. The penetration rate needs to be strictly controlled, usually not exceeding 100 mm / s, to avoid damage to the fins during penetration. In addition, during the penetration process, the anchor chain 8 is always connected to the top of the pile anchor, and the traction equipment on the installation ship maintains an appropriate tension to prevent the pile body from shifting, thereby improving the installation accuracy and stability.

[0023] S4. Retract the companion pile 6, the conduit 7, and the spraying device in sequence. At the same time, use the winch 11 to tighten the anchor chain 8. Conduct pre-driving the pile before the pile driving operation in S3. Control the hammering device to hammer the end of the conduit 7 exposed above the sea level until it settles by 1.2 - 2.5 times the length of the pile anchor body 1. After completing step S4, carry out stone pitching protection. The protection radius is 5 - 8 times the diameter of the pile anchor body 1, and the protection thickness is 1 - 1.5 times the diameter of the pile anchor body 1.

Claims

1. An ocean mooring pile anchor, characterized in that, Comprising: A pile-anchor main body (1), the pile-anchor main body (1) is arranged in a tubular shape, and fins (2) are arranged on the outer side wall of the pile-anchor main body (1); An umbrella cap (3), the umbrella cap (3) is a thin-walled shell, the shape of the umbrella cap (3) is an inverted frustum, the cross-section of the umbrella cap (3) shrinks linearly along the axial direction, and the overall is a conical curved surface structure with a large upper part and a small lower part. The umbrella cap (3) is fixedly arranged at one end of the pile-anchor main body (1), the large-area end face of the frustum of the umbrella cap (3) faces the pile-anchor main body (1), and the outer diameter of the fin (2) is smaller than the diameter of the large-area end of the frustum of the umbrella cap (3).

2. The marine mooring pile anchor according to claim 1, characterized in that, The umbrella cap (3) is sleeved on the pile-anchor main body (1), the diameter of the small-area end at the top of the frustum of the umbrella cap (3) is equal to the diameter of the pile-anchor main body (1), and the bottom of the frustum of the umbrella cap (3) is fixedly connected to the pile-anchor main body (1) through a rib plate.

3. The marine mooring pile anchor according to claim 1, wherein, The pile-anchor main body (1) is arranged as a hollow steel pipe, and an installation sleeve is fixedly arranged at one end of the pile-anchor main body (1) facing away from the umbrella cap (3). The installation sleeve is sleeved on the pile-anchor main body (1) to increase the wall thickness of this end of the pile-anchor main body (1).

4. The marine mooring pile anchor according to claim 1, wherein, A connection hole (4) is arranged at one end of the pile-anchor main body (1) facing away from the umbrella cap (3), and the connection hole (4) is used for installing an anchor chain (8).

5. The marine mooring pile anchor according to claim 1, characterized in that, The fins (2) are arranged as single-loop spiral blades evenly distributed on the outer side wall of the pile-anchor main body (1) or a single spiral blade is continuously wound around the outer side wall of the pile-anchor main body (1) for multiple turns.

6. An offshore mooring pile anchor construction structure, characterized in that For installing the marine mooring pile-anchor according to any one of claims 1-5, comprising: A pile-anchor installation ship (9), the pile-anchor installation ship (9) is used for transporting and carrying installation equipment; An accompanying pile (6), the accompanying pile (6) is installed at one end of the pile-anchor main body (1) facing away from the umbrella cap (3), and is used for providing an initial stable structure for the installation of the pile-anchor; A guide pipe (7), the guide pipe (7) is clamped at one end of the accompanying pile (6) facing away from the pile-anchor main body (1), and the guide pipe (7) is higher than the sea level after installation; A hammering device, the hammering device is arranged on the pile-anchor installation ship (9), and the hammering device includes a winch (11) and a pile hammer (12). The winch (11) is used for controlling the pile hammer (12) to hammer one end of the guide pipe (7) exposed above the sea level.

7. The marine mooring pile anchor construction structure according to claim 6, characterized in that, Further comprising: A jetting device, the jetting device includes a jetting pipe (5) and a high-pressure water pump (10). Jetting holes are arranged on the side wall of the umbrella cap (3). The high-pressure water pump (10) is arranged on the pile-anchor installation ship (9). One end of the jetting pipe (5) is inserted into the jetting hole, and the other end of the jetting pipe (5) is connected to the high-pressure water pump (10), and is used for jetting high-pressure water during installation to reduce the penetration resistance and improve the soil disturbance characteristics.

8. A construction method for a marine mooring pile anchor, characterized in that, For constructing and installing the marine mooring pile-anchor according to any one of claims 1-5 by using the construction structure of the marine mooring pile-anchor according to claim 7, comprising: S1. Carry out preparatory work, start the facilities, install the anchor chain (8), install the accompanying pile (6) at one end of the pile anchor body (1) facing away from the umbrella cap (3), and install the jet pipe (5) on the outer side wall of the pile anchor body (1) and insert one end into the jet hole; S2. Carry out hoisting operations, use hoisting equipment to hoist the pile anchor body (1) with the accompanying pile (6) installed to a preset position and maintain the vertical posture with the umbrella cap (3) facing downwards, and install the conduit (7); S3. Carry out pile driving operations, start the high-pressure water pump (10), spray high-pressure water to the bottom of the pile anchor body (1) to destroy the soil structure at the pile tip and promote local soil layer liquefaction. At this time, control the hammering device to carry out continuous hammering until the pile anchor system penetrates to a predetermined depth; S4. Retract the accompanying pile (6), the conduit (7) and the jetting device in sequence. At the same time, use the winch (11) to tighten the anchor chain (8).

9. The construction method of the marine mooring pile anchor according to claim 8, characterized in that, Before carrying out the pile driving operation in S3, carry out pre-piling first, control the hammering device to hammer the end of the conduit (7) exposed above the sea level until the settlement is 1.2 - 2.5 times the length of the pile anchor body (1).

10. The construction method of the marine mooring pile anchor according to claim 8, wherein After completing step S4, carry out riprap protection, with the protection radius being 5 - 8 times the diameter of the pile anchor body (1) and the protection thickness being 1 - 1.5 times the diameter of the pile anchor body (1).

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