Hydraulic dredging construction method for hard clay in offshore wind turbine jacket foundation piles

Abstract

The present invention relates to the field of wind power installation technology, and in particular to a construction method for hydraulic dredging of hard clay in offshore wind power conductor frame foundation piles, including construction preparation, ship positioning, ship adjustment, mud pumping in piles, mud surface elevation acceptance, and ship relocation and repositioning; the offshore wind power mud surface elevation control method of the present invention greatly reduces the use time of divers and achieves continuous operation throughout the day compared to the traditional method of divers using mud pumping pipes to pump mud by hand. For some situations where there is a lot of silt and the mud pumping depth is thick, the use of this mud pumping method can greatly promote construction efficiency. Using a cargo ship equipped with a crawler crane can reduce ship and machinery rental fees compared to traditional crane ships. After the mud pumping is completed, the divers conduct a high point inspection and guide the divers to pump mud at the high points to ensure that the mud surface height in the engineering piles is uniform.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power installation, and in particular to a construction method for hydraulic dredging of hard clay in foundation piles of an offshore wind power conductor frame. Background Art

[0002] After the jacket pile foundation sinks to the designed elevation, the mud surface elevation inside the pile is higher than the bottom of the jacket tip. A special mud pump is needed to desilt the pile, control the mud surface elevation inside the pile, avoid deviation in the jacket installation elevation, and control the maximum amount of grouting material.

[0003] During the deep-sea large-diameter pile foundation dredging construction process, through on-site construction progress and quality control, it was found that the existing low-pressure head and large-displacement dredging mode no longer meets the requirements of deep-sea dredging construction with complex and changeable geology. This dredging mode requires the use of a crane vessel, but the rental cost of a crane vessel is high and the operation is inflexible. At the same time, this dredging mode requires divers to be underwater for a long time. Since divers work for a long time in the water, the labor intensity is high and the risk is high. Summary of the Invention

[0004] To achieve the above-mentioned object, the present invention provides a hydraulic dredging construction method for hard clay in offshore wind turbine jacket foundation piles, comprising:

[0005] S100, construction preparation, confirm the sea conditions, and after the sea conditions meet the requirements, confirm the bow direction of the dredger and adjust the bow direction to be consistent with the surge direction; confirm the dredging depth according to the jacket tip depth;

[0006] S200, the ship is stationed, and the four anchors of the dredger are positioned on the sea surface;

[0007] S300, ship positioning: after the transport ship completes positioning of the engineering piles, the ship's operating position relative to the engineering piles is adjusted according to the ship positioning system;

[0008] S400, pumping mud from inside the pile, using a circuitous route with the engineering pile as the center;

[0009] S500, Mud surface elevation acceptance: Divers use underwater measuring ropes to measure the mud surface elevation within the mud pumping area. Using the jacket tip length as a reference, the difference between the pile top elevation and the tip length is calculated. If the pile top elevation is greater than the tip length, the mud surface depth within the pile meets the acceptance requirements.

[0010] S600: Move the ship and reposition it, repeat steps S200 to S500, and continue to complete the mud extraction work of the remaining piles.

[0011] In some possible implementations, S200 specifically includes the following steps:

[0012] S210, the anchor boat is on standby. When the chain anchor of the dredging vessel is lowered, the working anchor can be dropped. The anchoring order is based on the principle of giving priority to the windward anchor until all four anchors are dropped.

[0013] S220. After the four anchors are positioned, the construction vessel moves according to the pile position provided by the measuring equipment. After ensuring that the side launching point is a safe distance of about 2 to 3 meters from the near side pile edge, the vessel completes the positioning work.

[0014] In some possible implementations, the pile position positioning method in step S220 specifically includes the following steps:

[0015] S221: The diver goes into the water and controls the crane on the dredger to lower the dredger pump below the water surface using the slings. If the water is clear, the diver directs the crane to lower the dredger pump into the engineering pile. If the water is not clear, but the visible range is within 2 meters, the next step is performed.

[0016] S222: The diver directs the crane to continuously adjust the position of the dredge pump in the water until the dredge pump collides with the engineering pile;

[0017] S223. The preliminary position of the engineering pile is preliminarily determined by sound. The diver searches for the engineering pile in the confirmed preliminary water area until the position of the engineering pile is determined. The diver directs the crane to lower the sludge pump until the sludge pump completely falls into the engineering pile, and the positioning is completed.

[0018] In some possible implementations, the pile position positioning method in step S220 specifically includes the following steps:

[0019] S221: The diver goes into the water and controls the crane on the dredger to lower the dredger pump below the water surface using the slings. If the water is clear, the diver directs the crane to lower the dredger pump into the engineering pile. If the water is not clear, but the visible range is within 2 meters, the next step is performed.

[0020] S222. The crane simulates the approximate position of the pile in the water based on the real-time information from the measuring equipment, directs the crane to be lowered, and estimates the difference between the elevation of the bottom of the mud pump and the elevation of the top of the engineering pile;

[0021] S223. When the difference is negative, it is assumed that the dredge pump has entered the engineering pile, and the crane is controlled to adjust in three directions: the stern, the bow, and away from the side of the ship. If the hook heads are deflected in the opposite direction, the assumption is established, that is, the dredge pump has entered the engineering pile; if the hook heads do not deflect in the opposite direction in two or more directions, the assumption is not established, and the dredge pump has not entered the engineering pile; lift the dredge pump to a suitable height, re-confirm the position, and then lower it until the hook heads are deflected in the opposite direction.

[0022] In some possible implementations, the specific operations of step S400 are:

[0023] S410: Preliminarily determine the center position of the engineering pile based on its diameter, and use a crane to control the sling to lower the mud pump until it is inserted into the mud layer.

[0024] S420: The crane controls the dredging pump to move along the length of the ship, using the virtual position of the engineering pile on the water or the center marker as a critical reference. The dredging pump iterates along the width of the ship, moving in a circular route to dredge the dredging pump. This process is repeated until most of the dredging pumping volume in the layer is removed from the pile. Then, the dredging pumping work for the next layer is started.

[0025] S430: After extracting at least two layers of mud, change the mud extraction path in the direction of the ship width and iteratively in the direction of the ship length until the mud extraction work in the current engineering pile is completed;

[0026] S440: After completing the mud pumping work of the current engineering pile, the crane lifts the mud pump until it is lifted to a safe height, waiting for the mud surface elevation inspection and ship moving work.

[0027] In some possible implementations, step S500 also needs to be supplemented with the following: before measurement, the diver needs to first determine the location, area and height of the high point on the mud surface, and feedback the information to the water management personnel, who will conduct an on-site assessment to decide whether re-extraction is needed.

[0028] In some possible implementations, the sea conditions confirmed in step S100 specifically include weather, visibility, swell height, swell period, water flow speed, and wind speed.

[0029] In some possible implementations, the crane is a crawler crane.

[0030] In some possible implementations, in step S500 , the distance between the mud surface and the bottom of the jacket tip is 0.5-1 m.

[0031] Compared with the existing technology, the beneficial effects of the present invention are as follows: the hydraulic dredging construction method of the present invention for hard clay in the foundation piles of offshore wind turbine conductor frames is different from the traditional method of divers using a mud pumping pipe to pump mud by hand, which greatly reduces the use time of divers and, in a sense, achieves continuous operation throughout the day; for some situations where there is a lot of silt and the mud is pumped to a deep depth, the use of this mud pumping method can greatly improve construction efficiency. In addition, the use of cargo ships equipped with crawler cranes can reduce ship and machinery rental fees compared to traditional crane ships. After the mud is pumped, the divers conduct a high-point inspection and guide the mud pumping at the high points to ensure that the mud surface height in the engineering piles is uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 is a flow chart of an embodiment of the present invention;

[0034] Figure 2 Schematic diagram of the structure of the operation in the embodiment of the present invention.

[0035] Reference numerals: mud pump 1, air compressor 2, air compressor pipe 3, mud pumping pipe 4, mud suction head 5. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In the following, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "multiple" means two or more.

[0037] Reference Figure 1 , the hydraulic dredging construction method for hard clay in offshore wind turbine jacket foundation piles shown in the figure comprises:

[0038] S100, construction preparation, confirm the sea conditions, and after the sea conditions meet the requirements, confirm the bow direction of the dredger and adjust the bow direction to be consistent with the surge direction; confirm the dredging depth according to the jacket tip depth;

[0039] S200, the ship is stationed, and the four anchors of the dredger are positioned on the sea surface;

[0040] S300, ship positioning: after the transport ship completes positioning of the engineering piles, the ship's operating position relative to the engineering piles is adjusted according to the ship positioning system;

[0041] S400, pumping mud from inside the pile, using a circuitous route with the engineering pile as the center;

[0042] S500, Mud surface elevation acceptance: Divers use underwater measuring ropes to measure the mud surface elevation within the mud pumping area. Using the jacket tip length as a reference, the difference between the pile top elevation and the tip length is calculated. If the pile top elevation is greater than the tip length, the mud surface depth within the pile meets the acceptance requirements.

[0043] S600: Move the ship and reposition it, repeat steps S200 to S500, and continue to complete the mud extraction work of the remaining piles.

[0044] Among them, the sea conditions confirmed in step S100 specifically include weather, visibility, swell height, swell period, water flow speed and wind force. When the wind force is greater than level 6, the operating conditions are no longer met. At the same time, the swell situation is specifically judged according to the tonnage of the cargo ship. For example, for a 5,000-ton deadweight cargo ship, when the swell height is more than 1 meter and the period is more than 8 seconds, the bulk carrier can no longer provide operating conditions for mud pumping construction; under relatively severe weather conditions, a 5,000-ton deadweight cargo ship cannot operate under sea conditions with a wave height of 2 meters, a wind force of level 5, and a swell period of more than 7 seconds. In step S100, the bow of the mud pumping construction ship faces the wind and waves to reduce the component of the wind and waves acting in the direction of the ship's width, thereby reducing the roll of the ship, and then alleviating the shaking during the operation of the ship's lifting facilities, thereby improving the efficiency of mud pumping.

[0045] See also Figure 2 The equipment supporting the dredge pump 1 used in step S400 of the present invention also includes an air compressor 2, an air compressor pipe 3, a dredge suction pipe 4, and a dredge suction head 5. The air compressor 2 drives the dredge pump 1 and the dredge suction head 5 via the air compressor pipe 3, and discharges sludge through the dredge suction pipe 4. The air compressor 2 is mounted on a cargo ship. The sling actually lifts the dredge pump 1. In addition, to improve the suction efficiency of hard soil layers, an insert is welded to the dredge suction head 5 to break up harder mud blocks. Compared with traditional round suction heads, this improves the suction efficiency of hard soil.

[0046] This offshore wind turbine mud level control method significantly reduces diver time compared to traditional handheld mud extraction using a suction pipe. This, in a sense, enables 24-hour continuous operation, significantly improving construction efficiency for sites with heavy silt and deep extraction depths. Using a cargo ship equipped with a crawler crane reduces vessel and machinery rental costs compared to traditional crane vessels. After mud extraction is complete, divers conduct a high-point inspection and conduct guided mud extraction at these high points, ensuring a uniform mud level within the piles.

[0047] In some possible implementations, S200 specifically includes the following steps:

[0048] S210, the anchor boat is on standby. When the chain anchor of the dredging vessel is lowered, the working anchor can be dropped. The anchoring order is based on the principle of giving priority to the windward anchor until all four anchors are dropped.

[0049] S220. After the four anchors are positioned, the construction vessel moves according to the pile position provided by the measuring equipment. After ensuring that the side launching point is a safe distance of about 2 to 3 meters from the near side pile edge, the vessel completes the positioning work.

[0050] The ship transfer operation can be performed by tugboat, which is convenient for small-scale and small-scale operations. In addition, since the jacket generally has four plug points, corresponding to four engineering piles, in actual operation, in order to reduce the number of ship transfers, after anchoring once, the crane is usually moved on the cargo ship to adjust the position. In this way, mud can be pumped from two engineering piles at the same time at a single anchoring position. At the same time, during the installation of a jacket, only one ship transfer is required to complete the entire mud pumping operation.

[0051] In some possible implementations, the above-mentioned pile position positioning mainly includes two methods: above-water positioning and underwater positioning. The underwater positioning method is specifically as follows. The pile position positioning method in step S220 specifically includes the following steps:

[0052] S221: The diver goes into the water and controls the crane on the dredger to lower the dredger pump below the water surface using the slings. If the water is clear, the diver directs the crane to lower the dredger pump into the engineering pile. If the water is not clear, but the visible range is within 2 meters, the next step is performed.

[0053] S222: The diver directs the crane to continuously adjust the position of the dredge pump in the water until the dredge pump collides with the engineering pile;

[0054] S223. The preliminary position of the engineering pile is preliminarily determined by sound. The diver searches for the engineering pile in the confirmed preliminary water area until the position of the engineering pile is determined. The diver directs the crane to lower the sludge pump until the sludge pump completely falls into the engineering pile, and the positioning is completed.

[0055] In this embodiment, the sound produced by the mud pump colliding with the engineering pile is received by the diver. During this process, the diver can stand on the sling and move along with the mud pump. This arrangement enables the diver to directly determine the preliminary position of the engineering pile based on the sound or the vibration of the sling.

[0056] In some possible implementations, when operating in poor sea conditions, it is risky for divers to go into the water. In this case, positioning on the water can be used. The pile position positioning method in step S220 specifically includes the following steps:

[0057] S221: The diver goes into the water and controls the crane on the dredger to lower the dredger pump below the water surface using the slings. If the water is clear, the diver directs the crane to lower the dredger pump into the engineering pile. If the water is not clear, but the visible range is within 2 meters, the next step is performed.

[0058] S222. The crane simulates the approximate position of the pile in the water based on the real-time information from the measuring equipment, directs the crane to be lowered, and estimates the difference between the elevation of the bottom of the mud pump and the elevation of the top of the engineering pile;

[0059] S223. When the difference is negative, it is assumed that the dredge pump has entered the engineering pile, and the crane is controlled to adjust in three directions: the stern, the bow, and away from the side of the ship. If the hook heads are deflected in the opposite direction, the assumption is established, that is, the dredge pump has entered the engineering pile; if the hook heads do not deflect in the opposite direction in two or more directions, the assumption is not established, and the dredge pump has not entered the engineering pile; lift the dredge pump to a suitable height, re-confirm the position, and then lower it until the hook heads are deflected in the opposite direction.

[0060] While water positioning relies entirely on measurement equipment, it is highly feasible for large-diameter pile foundations. The measurement equipment in this application can be ultrasonic ranging equipment, sonar equipment, etc., which are prior art and will not be described in detail in this application. Furthermore, in this embodiment, the water positioning process does not require the use of divers, significantly reducing diving operation time and operational risks.

[0061] In some possible implementations, the specific operations of step S400 are:

[0062] S410: Preliminarily determine the center position of the engineering pile based on its diameter, and use a crane to control the sling to lower the mud pump until it is inserted into the mud layer.

[0063] S420: The crane controls the dredging pump to move along the length of the ship, using the virtual position of the engineering pile on the water or the center marker as a critical reference. The dredging pump iterates along the width of the ship, moving in a circular route to dredge the dredging pump. This process is repeated until most of the dredging pumping volume in the layer is removed from the pile. Then, the dredging pumping work for the next layer is started.

[0064] S430: After extracting at least two layers of mud, change the mud extraction path in the direction of the ship width and iteratively in the direction of the ship length until the mud extraction work in the current engineering pile is completed;

[0065] S440: After completing the mud pumping work of the current engineering pile, the crane lifts the mud pump until it is lifted to a safe height, waiting for the mud surface elevation inspection and ship moving work.

[0066] In this method, the entire operation does not require a diver to conduct the operation, which improves convenience and reduces risks. To determine the boundary of the engineering pile during the extraction process, the above-mentioned above-mentioned above-water positioning method can be used. This means that the crane can be controlled to adjust in any direction. When the hook head deflects in the opposite direction, it indicates that the dredge pump has contacted the boundary of the engineering pile.

[0067] In some possible implementations, step S500 also needs to be supplemented with the following: before measurement, the diver needs to first determine the location, area and height of the high point on the mud surface, and feedback the information to the water management personnel, who will conduct an on-site assessment to decide whether re-extraction is needed.

[0068] In some possible implementations, in order to ensure the quality of mud extraction and to ensure that the plug tip has sufficient spare space in the engineering pile, in step S500, the distance between the mud surface and the bottom of the plug tip on the jacket is 0.5-1 m.

[0069] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention shall be covered by the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A hydraulic dredging construction method for hard clay in offshore wind turbine jacket foundation piles, characterized in that: include: S100, construction preparation, confirm the sea conditions, and after the sea conditions meet the requirements, confirm the bow direction of the dredger and adjust the bow direction to be consistent with the surge direction; confirm the dredging depth according to the tip length of the jacket; S200, the ship is stationed, and the four anchors of the dredger are positioned on the sea surface; S300, ship positioning: after the dredging vessel completes positioning of the engineering pile, the operating position of the vessel relative to the engineering pile is adjusted according to the vessel positioning system; S400, pumping mud from inside the pile, using a circuitous route with the engineering pile as the center; S500, Mud surface elevation acceptance: Divers use underwater measuring ropes to measure the mud surface elevation within the mud pumping area. Using the jacket tip length as a reference, the difference between the pile top elevation and the tip length is calculated. When the pile top elevation is greater than the tip length, the mud surface depth within the pile meets the acceptance requirements. S600, move the ship and reposition it, repeat steps S200 to S500, and continue to complete the mud pumping work of the remaining piles; S200 specifically includes the following steps: S210, the anchor boat is on standby. When the chain anchor of the dredger is lowered, the working anchor can be dropped. The anchoring order is based on the principle of giving priority to the windward anchor until all four anchors are dropped. S220. After the four anchors are positioned, the dredger moves according to the pile position provided by the measuring equipment. After ensuring that the side launching point is 2 to 3 meters away from the near side pile edge, the vessel completes the stationing work. The pile position positioning method in step S220 specifically includes the following steps: S221: The diver goes into the water and controls the crane on the dredger to lower the dredger pump below the water surface using the slings. If the water is clear, the diver directs the crane to lower the dredger pump into the engineering pile. If the water is not clear, but the visible range is within 2 meters, the next step is performed. S222. The crane simulates the approximate position of the pile in the water based on the real-time information from the measuring equipment, directs the crane to be lowered to the correct position, and estimates the difference between the elevation of the bottom of the sludge pump and the elevation of the top of the engineering pile; S223. When the difference is negative, it is assumed that the dredge pump has entered the engineering pile. The crane is then controlled to adjust in three directions, namely, the stern, the bow, and away from the side of the ship. If the hook head deflects in opposite directions, the assumption is established, i.e., the dredge pump has entered the engineering pile. If the hook head does not deflect in opposite directions in more than two directions, the assumption is not established, i.e., the dredge pump has not entered the engineering pile. The dredge pump is lifted to a suitable height, and the position is re-confirmed before being lowered until the hook head deflects in opposite directions. The specific operations of step S400 are: S410: Preliminarily determine the center position of the engineering pile based on its diameter, and use a crane to control the sling to lower the mud pump until it is inserted into the mud layer. S420: The crane controls the dredging pump to move along the length of the ship, using the virtual position of the engineering pile on the water or the center marker as a critical reference. The dredging pump iterates along the width of the ship, moving in a circular route to dredge the dredging pump. This process is repeated until most of the dredging pumping volume in the layer is removed from the pile. Then, the dredging pumping work for the next layer is started. S430: After extracting at least two layers of mud, change the mud extraction path in the direction of the ship width and iteratively in the direction of the ship length until the mud extraction work in the current engineering pile is completed; S440: After completing the mud pumping work of the current engineering pile, the crane lifts the mud pump until it is lifted to a safe height, waiting for the mud surface elevation inspection and ship moving work.

2. The hydraulic dredging construction method for hard clay in offshore wind turbine jacket foundation piles according to claim 1, characterized in that: Step S500 also includes: before measurement, the diver needs to first determine the location, area and height of the high point on the mud surface, and feed back the information to the water management personnel, who will conduct on-site evaluation to decide whether re-extraction is needed.

3. The hydraulic dredging construction method for hard clay in offshore wind turbine jacket foundation piles according to claim 1, characterized in that: The sea conditions confirmed in step S100 specifically include weather, visibility, swell height, swell period, water flow speed and wind speed.

4. The hydraulic dredging construction method for hard clay in offshore wind turbine jacket foundation piles according to claim 1, characterized in that: The crane is a crawler crane.

5. The hydraulic dredging construction method for hard clay in offshore wind turbine jacket foundation piles according to claim 1, characterized in that: In step S500, the distance between the mud surface and the bottom of the jacket tip is 0.5-1 m.

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