A pile sinking method for offshore wind power pile foundation

Abstract

The present application belongs to the field of large steel cylinder vibration sinking construction device, and relates to a pile sinking method for offshore wind power pile foundation, which comprises ship station, platform adjustment platform position and elevation, anchor weight system lowering, initial pile driving of 1# pile by pile driving ship, platform holding 1# pile, pile driving of 2# pile by pile driving ship, platform displacement, holding of 1# and 2# piles, pile driving of 3# and 4# piles, platform removal and pile foundation re-driving to the elevation. The pile sinking method is realized based on a suspended positioning platform, and solves the problems of complex construction process, low construction efficiency, large cost investment, low precision, high risk and large safety hazard of traditional positioning by sitting bottom positioning platform and pile foundation construction by crane ship.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine pile driving construction equipment, and relates to a pile driving method, particularly a pile driving method for offshore wind turbine pile foundations. Background Technology

[0002] Wind power, as a clean energy source, has gained increasing application globally due to its advantage of utilizing renewable resources. Offshore wind power, with its advantages of stable and high wind speeds and no land occupation, has become a key development area in the wind power industry. However, constructing offshore wind farms also presents significant challenges, one of which is the much higher cost of foundation engineering compared to onshore wind farms. Therefore, reducing the construction cost of offshore wind farms is crucial for the development of offshore wind power.

[0003] Traditional offshore wind turbine foundation construction for steel piles employs a bottom-mounted pile stabilization platform for positioning and a crane vessel for driving the piles. This traditional method is highly susceptible to external environmental factors such as wind, waves, and currents, requires the installation of auxiliary piles, and necessitates the use of a crane vessel for relocation. Consequently, the construction process is lengthy and inefficient. Summary of the Invention

[0004] The purpose of this invention is to provide a pile driving method for offshore wind power pile foundations that is scientifically and rationally designed, convenient for construction, improves pile driving efficiency, saves pile driving costs, shortens the construction period, and is easy to implement.

[0005] The technical problem solved by this invention is achieved through the following technical solution:

[0006] A method for driving piles for offshore wind power foundations, characterized by the following steps:

[0007] Step 1: The piling vessel and barge are positioned at the designated location, anchored, and anchor floats are set.

[0008] Step 2: Use a piling vessel to hoist the floating positioning platform to the pile position and fill the pontoon with water to make the platform float below the sea level. Adjust the flatness of the floating positioning platform by filling and draining water in each compartment of the pontoon.

[0009] Step 3: Simultaneously lower 4 anchor systems into the seabed mud. At this time, the floating positioning platform will rise, tighten the anchor systems, adjust the tension of each anchor system to be equal, and adjust the flatness of the platform.

[0010] Step 4: With the assistance of the floating positioning platform, the piling vessel is used to carry out piling construction on piles 1#-4# respectively.

[0011] Step 5: After piles 1#-4# are driven, the floating positioning platform is raised to the surface by draining water through the pontoon, the anchor system is pulled out of the mud surface, the anchor is raised to the limit position, and the tugboat tows the floating positioning platform to the next machine position and temporarily positions it.

[0012] Step 6: The pile driving vessel hoists the pile driver onto the pile foundation. Relying on the pile frame and self-elevation stability of the pile driving vessel, piles #4, #3, #2, and #1 are driven back to the design elevation in sequence, and the pile position and verticality indicators are re-measured.

[0013] Furthermore, the aforementioned suspended positioning platform includes a platform main frame, pontoons, an anchor system, and a guide clamping device. The pontoons are installed on the platform main frame, and the anchor system is installed at the four corners of the bottom of the platform main frame. The guide clamping device includes a front guide clamping device and a rear guide clamping device. Front guide clamping devices are installed at both ends of the front part of the platform main body and are arranged vertically opposite each other. Rear guide clamping devices are symmetrically installed at both ends of the rear part of the platform main body.

[0014] Moreover, the main frame of the platform consists of a top frame, a bottom frame and longitudinal connecting beams. The top frame and the bottom frame are arranged horizontally opposite each other, and longitudinal connecting beams are evenly distributed between the top frame and the bottom frame.

[0015] The pontoon is installed at the bottom of the top frame, the anchor system is connected to the bottom of the base frame, the upper front guide clamping device and the lower rear guide clamping device are installed on the top frame, and the lower front guide clamping device and the lower rear guide clamping device are installed on the base frame.

[0016] Moreover, the interior of the pontoon is divided into several compartments by partitions, and each compartment of the pontoon is equipped with an inlet and outlet.

[0017] Moreover, the aforementioned front guide clamping device is a semi-fixed and semi-telescopic structure, which includes a fixed arm and a telescopic arm. The fixed arm is welded to the side end of the main frame of the platform, and a telescopic arm that can extend left and right is installed on the main frame of the platform at the rear end of the fixed arm. The telescopic arm is driven by an electric push rod. After the telescopic arm extends, it and the fixed arm together form a pile driving positioning area. Jacks are installed on the fixed arm, the telescopic arm and the main frame of the platform within the pile driving positioning area.

[0018] Furthermore, the rear guide clamping device is a telescopic structure, which includes a mounting frame, clamping clamps, and cylinders. The mounting frame, which can extend and retract left and right, is movably mounted on the platform frame. Clamping clamps, which are arranged front and rear, are hinged on the outer end of the mounting frame. The clamping clamps are arc-shaped structures, with the inner arc surfaces of the two clamping clamps installed opposite each other. A cylinder that drives the opening and closing of the clamping clamps is hinged on the outer side of the clamping clamps. The cylinder is connected to the mounting frame. Jacks are evenly installed on each clamping clamp at intervals.

[0019] Furthermore, the method for driving piles 1#-4# using a pile-driving vessel with the assistance of a floating positioning platform is as follows:

[0020] Step 4.1: Align the pile driving positioning area of ​​the front guide clamping device with the No. 1 pile position, and adjust the position of the front guide clamping device to leave a gap with the No. 1 pile foundation;

[0021] Step 4.2: The piling vessel lifts pile #1 and holds it within the pile driving positioning area. Pile #1 is then placed into the floating positioning platform and allowed to sink into the mud. The vibratory hammer on the piling vessel is then started to drive pile #1 into its initial position.

[0022] Step 4.3: Re-measure the actual coordinates and verticality of the pile position after the initial driving of pile #1, and calculate the coordinates of pile #2 based on the actual coordinates of pile #1. Adjust the jacks on the upper and lower front guide clamping devices of pile #1 in the floating positioning platform to clamp them tightly with pile #1, and assist the platform in driving and positioning the pile.

[0023] Step 4.4: Align the pile driving positioning area of ​​the front guide clamping device with the pile position of No. 2, and adjust the position of the guide clamping device to leave a gap with the No. 2 pile foundation;

[0024] Step 4.5: The piling vessel lifts and lowers pile #2 into the suspended positioning platform, which then sinks into the mud. The piling vessel then uses a vibratory hammer to drive pile #2 into its initial position.

[0025] Step 4.6: After the initial driving of pile #2 is completed, the coordinates of the pile top and the verticality index of pile #2 are re-measured, and the re-measured data of pile #1 and the verticality index are compared and analyzed with the initial data. At the same time, the coordinates of pile #3 are calculated accordingly.

[0026] Step 4.7: Loosen the front guide clamping device and fully retract the telescopic arm. Use the tow wheel to move the suspended platform. Use the rear guide clamping device to clamp piles #1 and #2 respectively. Check the plane torsion angle of the suspended platform to ensure that it meets the plane torsion angle deviation requirements.

[0027] Step 4.8, similarly, the piling vessel sequentially hoists and lowers piles #3 and #4, driving them to the initial driving elevation;

[0028] Step 4.9: Remeasure the final coordinates and verticality of piles 1#-4#.

[0029] The advantages and beneficial effects of this invention are as follows:

[0030] 1. The pile driving method for offshore wind power foundations solves the current problem of complex construction by redesigning the existing method of pile driving construction relying on a bottom-mounted pile stabilizing positioning platform to a method using a floating positioning platform. Specifically, by replacing the auxiliary pile positioning in the existing technology with the anchor weight system positioning, the problem of frequent hoisting operations caused by the need to use crane ships to hoist piles, vibratory hammers, and positioning frames is solved. This not only simplifies the construction process but also reduces construction risks and saves construction costs.

[0031] 2. The present invention has a scientific and reasonable structural design, and has the advantages of convenient construction, improved pile driving efficiency, reduced pile driving cost, shortened construction period and easy implementation. It is a highly innovative pile driving method for offshore wind power pile foundations. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention (assembled on the seabed);

[0033] Figure 2 This is a top view of the guide clamping device of the present invention in its retracted state;

[0034] Figure 3 This is a top view of the extended state of the guide clamping device of the present invention;

[0035] Figure 4 This is a schematic diagram of the rear guide clamping device of the present invention.

[0036] Figure 5 The following is a flowchart of the construction process for offshore wind power pile driving based on a floating positioning platform according to the present invention (Figure a. Positioning the floating positioning platform; Figure b. Initial driving of pile #1 by the pile driving vessel; Figure c. Driving pile #2 by the pile driving vessel; Figure d. Driving pile #3 by the crane vessel; Figure e. Driving pile #4 by the pile driving vessel; Figure f. Re-driving the pile foundation to the required elevation).

[0037] Figure Labels

[0038] 1-Equipment platform system, 2-Top frame, 3-Floating box, 4-Longitudinal connecting beam, 5-Guiding and clamping device, 6-Base frame, 7-Anchor system, 8-Rear guiding and clamping device, 9-Platform main frame, 10-Telescopic boom, 11-Fixed boom, 12-Jack, 13-Installation frame, 14-Cylinder, 15-Clamping clamp, 16-Floating positioning platform, 17-Pile position 1, 18-Pile position 2, 19-Pile position 3, 20-Pile position 4, 21-Pile driving vessel. Detailed Implementation

[0039] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0040] As an auxiliary tooling equipment for wind power pile foundation construction, the floating positioning platform is mainly used to control the absolute position of the pile foundation, the relative position between each pile, and the verticality of the pile foundation. By controlling these indicators, the pile foundation construction can meet the standard specifications and design requirements, which facilitates the construction of subsequent structures such as jackets or pile caps.

[0041] During pile driving, the suspended positioning platform is initially positioned, with its main structure suspended below sea level in a location less affected by waves. A pile driving vessel is used to control the accuracy of the pile foundation, and it drives pile #1. Based on pile #1, the suspended positioning platform's clamping device clamps pile #1, and the pile driving vessel drives pile #2. The suspended platform then shifts, and the clamping device shifts to clamp piles #1 and #2, and the pile driving vessel drives piles #3 and #4 in sequence. After the platform shifts, the pile driving vessel re-drives the pile foundation to the design elevation.

[0042] The pile driving method for offshore wind power foundations can effectively solve the problems of complex construction processes, low construction efficiency, high cost, low accuracy, high risk, and significant safety hazards associated with traditional methods that use positioning platforms for positioning and crane vessels for pile driving.

[0043] The construction process is as follows:

[0044] Ship positioning → Platform placement and adjustment of platform position and elevation → Lowering of anchor system → Initial driving of pile #1 by piling vessel → Platform holding pile #1 tightly → Piling vessel driving pile #2 → Platform repositioning and holding piles #1 and #2 tightly → Driving piles #3 and #4 → Removal of platform → Re-driving of piles to the required elevation.

[0045] The specific steps are as follows:

[0046] The piling vessel 21 and the barge were positioned at the designated location, and anchored and set up anchor floats;

[0047] The floating positioning platform 16 is hoisted to the pile position using a piling vessel, and water is injected into the pontoon to make the platform float below the sea level. The flatness of the floating positioning platform is adjusted by injecting and dewatering water into each compartment of the pontoon.

[0048] Four anchor systems are simultaneously lowered into the seabed mud. At this time, the floating positioning platform will rise, tighten the anchor systems, adjust the tension of each anchor system to be equal, and adjust the flatness of the platform.

[0049] Start pile driving:

[0050] like Figure 5As shown in (a), the pile positioning area (gap) of the front guide clamping device is aligned with pile position 17 of #1, and the position of the front guide clamping device is adjusted to leave a gap with pile foundation #1. The pile driving vessel lifts pile #1 and clamps it into its gap, then places pile #1 into the floating positioning platform to sink into the mud. The vibratory hammer on the pile driving vessel is then started to drive pile #1 into its initial position. During the driving of pile #1, the planar position and verticality of pile foundation #1 are controlled by the stability and verticality control facilities of the pile driving vessel itself.

[0051] like Figure 5 (b) The actual coordinates and verticality of the pile position after the initial driving of pile #1 were remeasured, and the coordinates of pile #2 were calculated based on the actual coordinates of pile #1. The jacks on the upper and lower front guide clamping devices of pile #1 in the floating positioning platform were adjusted to clamp the pile position of pile #1, and the platform was used to drive the pile in a positioning manner.

[0052] like Figure 5 As shown in (c), the pile positioning area (opening) of the front guide clamping device is aligned with the pile position of #2, and the position of the guide clamping device is adjusted to leave a gap with the pile foundation of #2. The pile driving vessel lifts and lowers pile #2 into the floating positioning platform, which then sinks into the mud. The pile driving vessel then uses a vibratory hammer to initially drive pile #2 into place. After the initial driving of pile #2 is completed, the coordinates of the pile top and the verticality index of pile #2 are re-measured, and the re-measured data of pile #1 and the verticality index are compared and analyzed with the initial data. At the same time, the coordinates of pile #3 (position 19) are calculated based on this data.

[0053] Release the front guide clamping device and fully retract the telescopic boom. Use the tugboat to move the suspended platform, and use the rear guide clamping device to clamp piles #1 and #2 respectively. Check the plane torsion angle of the suspended platform to ensure that it meets the plane torsion angle deviation requirements.

[0054] Similarly, the piling vessel sequentially lowered piles #3 and #4 at positions 20 on each of pile positions #3 and #4. Figure 5 As shown in (d)-(e); and then hoist it to the initial elevation, as shown in the diagram. Figure 5 As shown in (f), the final coordinates and verticality indices of piles #1 to #4 were remeasured.

[0055] The floating positioning platform is raised to the surface by draining water from the pontoon, the anchor system is pulled out of the mud, and the anchor system is raised to its limit position. A tugboat then tows the floating positioning platform to the next machine location and temporarily positions it.

[0056] The piling vessel hoisted the pile driver onto the pile foundation, and relying on the piling vessel's pile frame and self-elevating stability, successively drove piles #4, #3, #2, and #1 to the design elevation, and then re-measured the pile position and verticality indicators.

[0057] The suspended positioning platform includes a platform main frame 9, a pontoon 3, an anchor system 7 and a guide clamping device 5. An equipment platform system 1 for controlling the guide clamping device is also installed on the platform main frame.

[0058] The main frame of the platform consists of a top frame 2, a bottom frame 6 and longitudinal connecting beams 4. The top frame and the bottom frame are arranged horizontally opposite each other, and longitudinal connecting beams are evenly distributed between the top frame and the bottom frame.

[0059] The pontoon is installed at the bottom of the top frame and covers the entire bottom of the top frame; the anchor system is connected to the bottom of the base frame; the guide clamping device includes a front guide clamping device and a rear guide clamping device 8. Front guide clamping devices are installed at both ends of the front top frame and base frame of the platform body, and rear guide clamping devices are installed symmetrically at both ends of the rear top frame and base frame of the platform body.

[0060] The pontoon is a box girder structure, and its interior is divided into several compartments by partitions. Each compartment of the pontoon is equipped with an inlet and outlet for water. Its main functions are: first, to control the levitation position of the floating positioning platform by water injection and drainage; second, to adjust the planar accuracy of the platform by water injection and drainage in different compartments; and third, to make the floating positioning platform float up by drainage, thereby pulling the anchor system out of the mud.

[0061] The aforementioned front guide clamping device is a semi-fixed and semi-telescopic structure, which includes a fixed arm 11 and a telescopic arm 10. The fixed arm is an L-shaped structure. The fixed arm is welded to the side end of the main frame of the platform. A telescopic arm that can extend left and right is installed on the main frame of the platform at the rear end of the fixed arm. The telescopic arm is driven by a cylinder or an electric push rod. After the telescopic arm extends, it and the fixed arm together form a pile driving positioning area. Jacks 12 are installed on the fixed arm, the telescopic arm and the main frame of the platform within the pile driving positioning area.

[0062] The rear guide clamping device is a telescopic structure, which includes a mounting frame 13, clamping clamps 15, and a cylinder 14. The mounting frame, which can extend and retract left and right, is movably mounted on the platform frame. The mounting frame is driven by a cylinder or an electric push rod. Clamping clamps, which are arranged front and rear, are hinged on the outer end of the mounting frame. The clamping clamps are arc-shaped structures, and the inner arc surfaces of the two clamping clamps are installed opposite each other. A cylinder that drives the opening and closing of the clamping clamps is hinged on the outer side of the clamping clamps. The cylinder is connected to the mounting frame. Jacks are evenly installed on each clamping clamp at intervals.

[0063] The main functions of the guiding and clamping device are: firstly, to guide and position the piles, facilitating their initial placement at the designated pile locations; and secondly, to clamp the driven piles, integrating them into the overall structure. The guiding and clamping device consists of two layers, with four sets in each layer. These are located at the four pile locations. The four sets at the front of the platform's main frame are semi-fixed, semi-retractable front guiding and clamping devices, while the four sets at the rear of the platform are retractable rear guiding and clamping devices. The semi-fixed, semi-retractable structure offers high strength and height, resulting in excellent load-bearing capacity; the retractable structure facilitates platform relocation and operation.

[0064] The main function of the anchor system is to provide anchoring force for the initial positioning of the suspended positioning platform, prevent changes in buoyancy caused by water level fluctuations due to tidal differences, and thus avoid instability caused by the platform floating up and down.

[0065] This invention effectively solves the problems of traditional offshore wind turbine pile foundation construction, where the bottom-mounted pile stabilization platform is greatly affected by external environmental factors such as wind, waves, currents, and tides, resulting in limited construction windows and impacting construction progress. It shortens the construction period by 20%. It also effectively solves the problems of frequent and high-risk hoisting operations involving crane vessels, vibratory hammers, and positioning frames in traditional offshore wind turbine pile foundation construction. Furthermore, it addresses the issue of poor accuracy in traditional offshore wind turbine pile foundation construction, which leads to difficulties and long cycles in the later installation of structures such as jackets. Using this pile driving method, the planar position and verticality of the driven offshore wind turbine piles meet 100% of the design requirements. Finally, it effectively solves the problem of poor mobility in changing pile driving sites with traditional bottom-mounted pile stabilization platforms, reducing preparation work and construction procedures, thus improving the overall pile driving efficiency of offshore wind power, reducing offshore operation time, and lowering offshore operation risks.

[0066] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A method for driving piles for offshore wind power foundations, characterized in that: Includes the following steps: Step 1: The piling vessel and barge are positioned at the designated location, anchored, and anchor floats are set. Step 2: Use a piling vessel to hoist the floating positioning platform to the pile position and fill the pontoon with water to make the platform float below the sea level. Adjust the flatness of the floating positioning platform by filling and draining water in each compartment of the pontoon. Step 3: Simultaneously lower 4 anchor systems into the seabed mud. At this time, the floating positioning platform will rise, tighten the anchor systems, adjust the tension of each anchor system to be equal, and adjust the flatness of the platform. Step 4: With the assistance of the floating positioning platform, the piling vessel is used to carry out piling construction on piles 1#-4# respectively. Step 5: After piles 1#-4# are driven, the floating positioning platform is raised to the surface by draining water through the pontoon, the anchor system is pulled out of the mud surface, the anchor is raised to the limit position, and the tugboat tows the floating positioning platform to the next machine position and temporarily positions it. Step 6: The pile driving vessel hoists the pile driver onto the pile foundation. Relying on the pile frame and self-elevation stability of the pile driving vessel, piles #4, #3, #2, and #1 are driven back to the design elevation in sequence, and the pile position and verticality index are re-measured. The suspended positioning platform includes a platform main frame, pontoons, anchor systems, and guide clamping devices. The pontoons are installed on the platform main frame, and the anchor systems are installed at the four bottom corners of the platform main frame. The guide clamping devices include front guide clamping devices and rear guide clamping devices. Front guide clamping devices are installed at both ends of the front part of the platform main frame and are arranged vertically opposite each other. Rear guide clamping devices are symmetrically installed at both ends of the rear part of the platform main frame. The method for driving piles 1#-4# using a pile-driving vessel with the assistance of a floating positioning platform is as follows: Step 4.1: Align the pile driving positioning area of ​​the front guide clamping device with the No. 1 pile position, and adjust the position of the front guide clamping device to leave a gap with the No. 1 pile foundation; Step 4.2: The piling vessel lifts pile #1 and holds it within the pile driving positioning area. Pile #1 is then placed into the floating positioning platform and allowed to sink into the mud. The vibratory hammer on the piling vessel is then started to drive pile #1 into its initial position. Step 4.3: Re-measure the actual coordinates and verticality of the pile position after the initial driving of pile #1, and calculate the coordinates of pile #2 based on the actual coordinates of pile #1. Adjust the jacks on the upper and lower front guide clamping devices of pile #1 in the floating positioning platform to clamp them tightly with pile #1, and assist the platform in driving and positioning the pile. Step 4.4: Align the pile driving positioning area of ​​the front guide clamping device with the pile position of No. 2, and adjust the position of the guide clamping device to leave a gap with the No. 2 pile foundation; Step 4.5: The piling vessel lifts and lowers pile #2 into the suspended positioning platform, which then sinks into the mud. The piling vessel then uses a vibratory hammer to drive pile #2 into its initial position. Step 4.6: After the initial driving of pile #2 is completed, the coordinates of the pile top and the verticality index of pile #2 are re-measured, and the re-measured data of pile #1 and the verticality index are compared and analyzed with the initial data. At the same time, the coordinates of pile #3 are calculated accordingly. Step 4.7: Loosen the front guide clamping device and fully retract the telescopic arm. Use the tow wheel to move the suspended platform. Use the rear guide clamping device to clamp piles #1 and #2 respectively. Check the plane torsion angle of the suspended platform to ensure that it meets the plane torsion angle deviation requirements. Step 4.8, similarly, the piling vessel sequentially hoists and lowers piles #3 and #4, driving them to the initial driving elevation; Step 4.9: Remeasure the final coordinates and verticality of piles 1#-4#.

2. The method for driving piles for offshore wind power foundations according to claim 1, characterized in that: The main frame of the platform consists of a top frame, a bottom frame, and longitudinal connecting beams. The top frame and the bottom frame are arranged horizontally opposite each other, and longitudinal connecting beams are evenly distributed between the top frame and the bottom frame. The pontoon is installed at the bottom of the top frame, the anchor system is connected to the bottom of the base frame, the upper front guide clamping device and the lower rear guide clamping device are installed on the top frame, and the lower front guide clamping device and the lower rear guide clamping device are installed on the base frame.

3. The method for driving piles for offshore wind power foundations according to claim 1, characterized in that: The interior of the pontoon is divided into several compartments by partitions, and each compartment of the pontoon is equipped with an inlet and outlet.

4. The method for driving piles for offshore wind power foundations according to claim 1, characterized in that: The aforementioned front guide clamping device is a semi-fixed and semi-telescopic structure, which includes a fixed arm and a telescopic arm. The fixed arm is welded to the side end of the main frame of the platform, and a telescopic arm that can extend left and right is installed on the main frame of the platform at the rear end of the fixed arm. The telescopic arm is driven by an electric push rod. After the telescopic arm extends, it and the fixed arm together form a pile driving positioning area. Jacks are installed on the fixed arm, the telescopic arm and the main frame of the platform within the pile driving positioning area.

5. The method for driving piles for offshore wind power foundations according to claim 1, characterized in that: The rear guide clamping device is a telescopic structure, which includes a mounting frame, clamping clamps, and cylinders. The mounting frame, which can extend and retract left and right, is movably mounted on the main frame of the platform. Clamping clamps, which are arranged front and rear, are hinged on the outer end of the mounting frame. The clamping clamps are arc-shaped structures, with the inner arc surfaces of the two clamping clamps installed opposite each other. A cylinder that drives the opening and closing of the clamping clamps is hinged on the outer side of the clamping clamps. The cylinder is connected to the mounting frame. Jacks are evenly installed on each clamping clamp at intervals.

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