Dismounting device and method for pile foundation

Abstract

The invention relates to the technical field of offshore wind power, and discloses a dismantling device and method for a pile type foundation. According to the dismounting device for the pile foundation, the annular fluid cavity is formed by the connecting cylinder and the outer wall of the pile foundation, pressure difference control is achieved through suction / injection of the fluid driving part, the dismounting device is directly and fixedly connected with the pile foundation through the jacking mechanism, axial force is applied in a mechanical transmission or hydraulic driving mode, and the dismounting effect is achieved. The whole pile foundation can be accurately controlled to be pulled up or sunk through the connecting cylinder. Compared with a traditional scheme, manual cutting by a diver is not needed, separation operation of the pile foundation and the seabed soil body is completed through the fluid dynamics principle, direct safety threats caused by environmental factors such as water flow disturbance, insufficient visibility and underwater biological interference to personnel are thoroughly avoided, and therefore operation safety is improved, and dismantling operation is more reliable.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power technology, and more specifically to a device and method for dismantling pile foundations. Background Technology

[0002] Offshore wind power, as a clean and renewable energy source, boasts significant advantages such as abundant resources, high power generation efficiency, and minimal environmental impact, making it a crucial force driving energy structure transformation and experiencing rapid development. With the continuous growth of installed offshore wind power capacity, the technical aspects of related facilities, including installation, operation, maintenance, and dismantling, are receiving increasing attention. Among these, monopile foundations, due to their simple structure and strong adaptability, are widely used in offshore wind power support structures.

[0003] In the field of offshore wind power foundation dismantling, the current practice is to draw on the experience of industries such as offshore oil and gas or bridges, and adopt the pile cutting process. Specifically, firstly, the seabed soil within a certain depth range around the pile is removed using underwater dredging equipment, exposing part of the pile body; then, professional divers dive underwater and cut the pile body at the predetermined location, thereby achieving the separation of the foundation from the superstructure.

[0004] However, during the demolition of the piles, it was found that divers had to work in a complex underwater environment for extended periods. This not only presented them with multiple uncertainties such as water flow, visibility, and underwater life, but also posed a significant threat to their personal safety, severely restricting the reliability of the demolition operation. Summary of the Invention

[0005] This invention provides a device and method for dismantling pile foundations, which solves the problem that traditional pile dismantling methods require divers to be in a complex underwater environment for a long time, facing multiple uncertain factors such as water flow, visibility and underwater organisms.

[0006] In a first aspect, the present invention provides a demolition device for pile foundations, comprising a connecting cylinder, a fluid drive component, and a lifting mechanism. The connecting cylinder has a cylindrical structure with one open end. The end of the connecting cylinder opposite to its opening is movably sleeved on the outside of the pile foundation, and the sleeved portion is subject to sliding sealing treatment. An annular fluid chamber is formed between the inner wall of the connecting cylinder and the outer wall of the pile foundation. The fluid drive component is used to connect the fluid chamber to draw or inject fluid, creating a pressure difference between the inside of the connecting cylinder and the external environment, thereby controlling the sinking or lifting of the connecting cylinder. The lifting mechanism is installed at the sleeved portion and is used to fix it to the pile foundation so as to drive the entire pile foundation to move.

[0007] Beneficial Effects: By forming an annular fluid chamber between the connecting cylinder and the outer wall of the pile foundation, differential pressure control is achieved through the suction / injection of fluid-driven components. The cylinder is directly fixed to the pile foundation via a jacking mechanism, and axial force is applied through mechanical transmission or hydraulic drive. This allows for precise control of the overall lifting or sinking of the pile foundation. Compared to traditional methods, this eliminates the need for manual cutting by divers. Instead, it utilizes fluid dynamics principles to separate the pile foundation from the seabed soil, completely avoiding direct safety threats posed by environmental factors such as water flow disturbance, insufficient visibility, and underwater biological interference. This enhances operational safety and makes dismantling operations more reliable. Furthermore, using a jacking mechanism to dismantle the pile foundation as a whole avoids problems such as uneven cuts and structural damage caused by underwater cutting, enabling complete recovery and reducing potential pollution to the marine environment.

[0008] In one optional embodiment, the lifting mechanism includes an outer ring, a hydraulic chamber, an inner ring, and a hydraulic drive component. The outer ring is installed on the inner wall of the connecting cylinder at the sleeve location; the hydraulic chamber is configured as a ring structure and located inside the outer ring; the inner ring is connected to the hydraulic chamber to increase the contact area and friction with the outer wall of the pile foundation; the hydraulic drive component is used to adjust the hydraulic pressure inside the hydraulic chamber to drive the inner ring to press and fix it to the pile foundation.

[0009] In one alternative embodiment, the inner wall of the inner ring is provided with a radially concentric anti-slip protrusion for abutting against the outer wall of the pile foundation.

[0010] In one alternative embodiment, the connecting cylinder includes a top cover at one end opposite to the opening, and the top cover has a drain hole; the fluid drive component is connected to the drain hole via an injection pipe.

[0011] In one optional embodiment, the connecting cylinder is provided with several partitions to divide the fluid chamber into multiple independent adjustment chambers. Each adjustment chamber is independently connected to the fluid drive component and is used to adjust the verticality of the connecting cylinder during sinking or pulling.

[0012] In one alternative embodiment, the demolition device for the pile foundation further includes lifting lugs fixedly connected to the connecting cylinder for connecting lifting equipment.

[0013] Secondly, the present invention also provides a method for dismantling pile foundations, applied to the pile foundation dismantling device provided in the preceding aspect. The dismantling method includes the following steps: sinking: lowering the connecting cylinder to the outside of the pile foundation to be dismantled, using the self-weight of the connecting cylinder and the negative pressure generated by the pumping of water by the fluid drive component to sink the connecting cylinder into the seabed; fixing: activating the hydraulic drive component to clamp the pile foundation; jacking: activating the fluid drive component to inject water into the connecting cylinder, causing the connecting cylinder to be pulled upward, thereby pulling the pile foundation upward as a whole; cycling: repeating the sinking, fixing, and jacking steps until the pile foundation is completely loosened; lifting: using lifting equipment to pull the connecting cylinder and the pile foundation out of the seabed as a whole.

[0014] Beneficial effects: During the sinking phase, a negative pressure sinking mechanism is created by utilizing the self-weight of the connecting cylinder and the negative pressure generated by the pumping of water by the fluid drive component, allowing the connecting cylinder to sink into the seabed. During the fixing phase, the pile foundation is clamped by the hydraulic drive component without the need for diver intervention, and the clamping force can be dynamically adjusted. During the jacking phase, when water is injected into the connecting cylinder, the fluid pressure pushes the cylinder upward, causing the pile foundation to move as a whole, and the fluid pressure is converted into axial force. During the circulation phase, the adhesion force between the pile foundation and the seabed soil is gradually decomposed by repeating the sinking, fixing, and jacking steps. During the lifting phase, the connecting cylinder and the pile foundation are pulled out of the seabed as a whole. In other words, compared with the traditional pile cutting process that requires manual operation by divers, this method does not require cutting the pile body throughout the entire process, reducing the time and frequency of workers' exposure to high-risk environments, avoiding the local damage to the pile body caused by traditional cutting operations, thereby reducing the risk of structural instability, reducing the need for secondary treatment due to local pile foundation fracture, and avoiding environmental risks such as water flow disturbance, insufficient visibility, and underwater organisms.

[0015] In one optional implementation, the sinking step includes: gravity penetration: relying on the weight of the connecting cylinder to initially penetrate the seabed; suction penetration: activating the fluid drive to draw fluid from the fluid chamber inside the connecting cylinder, using negative pressure suction to drive the connecting cylinder to continue penetrating.

[0016] In one optional implementation, the lifting step further includes: leveling: real-time monitoring of the tilt angle of the connecting cylinder, and when the tilt angle exceeds a preset threshold, controlling the fluid drive component to perform differentiated suction or injection on the multiple adjustment chambers separated in the connecting cylinder to adjust the pressure difference in each chamber, thereby correcting the verticality of the connecting cylinder.

[0017] In one optional implementation, the jacking step further includes: emergency control: real-time monitoring of the pull-out force of the pile foundation; when it is determined that the pull-out force has suddenly dropped and exceeded the preset safety threshold, it is determined that the pile foundation has suddenly loosened, and at least one of the following operations is immediately performed: suspending the pull-out of the hoisting equipment, adjusting the clamping state of the jacking mechanism, and adjusting the water injection pressure of the fluid drive component.

[0018] In one alternative implementation, prior to the sinking step, the method further includes: resistance estimation: based on geological survey data, calculating the sum of the side friction resistance and gravity of the pile foundation to estimate the minimum clamping force required by the jacking mechanism and the minimum upward pull pressure required by the fluid drive component. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A perspective view of the dismantling device for pile foundations after installation, provided in an embodiment of the present invention. Figure 2 A perspective view of a demolition device for a pile foundation installed on a pile foundation, as provided in an embodiment of the present invention. Figure 3 A top view of a demolition device for pile foundations provided in an embodiment of the present invention; Figure 4 A cross-sectional view of the installation of the demolition device for pile foundations and the pile foundation provided in an embodiment of the present invention; Figure 5 A cross-sectional view of the jacking mechanism in the demolition device for pile foundations provided in an embodiment of the present invention; Figure 6 This is a partial cross-sectional view of the jacking mechanism in the demolition device for pile foundations provided in an embodiment of the present invention; Figure 7 Another partial cross-sectional view of the jacking mechanism in the demolition device for pile foundations provided in an embodiment of the present invention; Figure 8 A top view of the connecting cylinder with four adjustable chambers in the demolition device for pile foundations provided in an embodiment of the present invention; Figure 9 A top view of the connecting cylinder with eight adjustable chambers in the demolition device for pile foundations provided in an embodiment of the present invention; Figure 10 This is a flowchart illustrating a method for demolishing pile foundations according to an embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1. Connecting cylinder; 101. Top cover; 102. Drainage hole; 103. Baffle plate; 104. Regulating compartment; 2. Fluid drive components; 3. Lifting mechanism; 301. Outer ring; 302. Hydraulic chamber; 303. Inner ring; 304. Anti-slip protrusion; 4. Lifting lugs; 5. Pile foundation; 6. Cables; 7. Control terminal; 8. Hoisting steel cables; 9. Lifting equipment; 10. Lifting equipment; 11. Ships; 12. Control cabin. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The following is combined with Figures 1 to 10 The following describes embodiments of the present invention.

[0024] According to an embodiment of the present invention, in one aspect, a demolition device for pile foundations is provided, such as... Figure 1 As shown, it includes a connecting cylinder 1, a fluid drive component 2, and a lifting mechanism 3.

[0025] like Figure 1 and Figure 2 As shown, the connecting cylinder 1 has a cylindrical structure with one end open. The end of the connecting cylinder 1 opposite to its opening is movably sleeved on the outside of the pile foundation 5, and the sleeved part is treated with sliding sealing. The inner wall of the connecting cylinder 1 and the outer wall of the pile foundation 5 enclose an annular fluid chamber. The fluid driving component 2 is used to connect the fluid chamber to draw or inject fluid, forming a pressure difference between the inside of the connecting cylinder 1 and the external environment, and controlling the sinking or lifting of the connecting cylinder 1. The lifting mechanism 3 is installed at the sleeved part and is used to fix it to the pile foundation 5 so as to drive the pile foundation 5 to move as a whole.

[0026] This configuration, by forming an annular fluid chamber between the connecting cylinder 1 and the outer wall of the pile foundation 5, allows for differential pressure control through the suction / injection of the fluid drive component 2. The lifting mechanism 3 is directly and fixedly connected to the pile foundation 5, and axial force is applied via mechanical transmission or hydraulic drive. This allows for precise control of the overall upward or downward movement of the pile foundation 5 through the connecting cylinder 1. Compared to traditional methods, this eliminates the need for manual cutting by divers. Instead, it utilizes fluid dynamics principles to separate the pile foundation 5 from the seabed soil, completely avoiding direct safety threats to personnel from environmental factors such as water flow disturbance, insufficient visibility, and underwater biological interference. This enhances operational safety and makes the demolition operation more reliable.

[0027] Meanwhile, by using the lifting mechanism 3 to dismantle the pile foundation 5 as a whole, problems such as uneven cuts and damage to the pile structure caused by underwater cutting can be avoided, and complete recovery can be achieved, reducing potential pollution to the marine environment.

[0028] It can be explained that the electrical connection of the fluid drive component 2 is connected to the control terminal 7 via cable 6 to transmit control signals and realize the regulation of the fluid drive component 2.

[0029] In one embodiment, such as Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the lifting mechanism 3 includes an outer ring 301, a hydraulic chamber 302, an inner ring 303, and a hydraulic drive component. The outer ring 301 is installed at the sleeve joint and connects to the inner wall of the cylinder 1; the hydraulic chamber 302 is configured as a ring structure and located inside the outer ring 301; the inner ring 303 is connected to the hydraulic chamber 302 to increase the contact area and friction with the outer wall of the pile foundation 5; the hydraulic drive component is used to adjust the hydraulic pressure inside the hydraulic chamber 302 and drive the inner ring 303 to press and fix it to the pile foundation 5.

[0030] This design allows for flexible use by construction personnel by adjusting the pressure inside the hydraulic chamber 302 using hydraulic drive components.

[0031] For example, during the installation process, the pressure inside the hydraulic chamber 302 is reduced to increase the gap between the inner ring 303 and the pile foundation 5, making it easier for the inner ring 303 to move along the axial direction of the pile foundation 5. After the inner ring 303 reaches the target position, the pressure inside the hydraulic chamber 302 is increased until the inner ring 303 clamps the pile foundation 5, making it easier to pull it up during dismantling.

[0032] Meanwhile, the contact pressure between the inner ring 303 and the outer wall of the pile foundation 5 can be dynamically adjusted. When the pile foundation 5 undergoes slight displacement or is subjected to external disturbances (such as water flow impact or seabed soil loosening), the system can quickly compensate for the clamping force through real-time pressurization to ensure that the clamping interface is always in a high friction state, effectively preventing the pile foundation 5 from slipping or becoming unstable.

[0033] In addition, the ring structure allows the clamping force to be evenly distributed along the circumference of the pile foundation, avoiding stress concentration caused by traditional point contact or local clamping, thereby improving the reliability of the clamping action under complex working conditions.

[0034] It can be noted that the outer ring 301 is coaxially sleeved outside the inner ring 303.

[0035] It can be noted that the outer ring 301 is rigidly connected to the inner wall of the connecting cylinder 1.

[0036] It should be noted that this embodiment does not impose specific limitations on the selection of hydraulic drive components.

[0037] Preferably, the hydraulic drive component is a hydraulic motor.

[0038] The hydraulic drive components include a start-up phase, a pressure regulation phase, a pressure maintenance phase, and a reset phase.

[0039] The start-up and pressure regulation phases include: the control terminal issues a command to start the hydraulic motor (e.g., an electric motor), the hydraulic motor drives the hydraulic pump to draw hydraulic oil from the oil tank to form a pressurized oil body, the pressurized oil body enters the annular cavity of the hydraulic chamber 302 through the hydraulic pipeline, and as the pressurized oil body is continuously injected, the pressure inside the hydraulic chamber 302 gradually increases, pushing the inner ring 303 to move radially inward (i.e., in the direction of the pile foundation 5), so that the inner ring 303 is in close contact with the outer wall of the pile foundation 5 under the action of hydraulic pressure, and achieves compression and fixation by increasing the contact area and friction.

[0040] When the hydraulic drive is in the pressure maintenance stage, that is, when it needs to be in the pressure holding state, the lifting mechanism 3 is equipped with a pressure sensor and a solenoid valve (such as an overflow valve or a reversing valve) to monitor the pressure of the hydraulic chamber 302 in real time. If the pressure drops, the hydraulic motor continues to drive the hydraulic pump to replenish the pressure oil; if the pressure is too high, the overflow valve or reversing valve may open to release pressure and maintain a constant clamping force.

[0041] Of course, when the hydraulic drive is in the reset phase, the lifting mechanism also includes a reversing valve. The control terminal issues a command to switch the flow direction of the reversing valve, so that the pressure oil in the hydraulic chamber 302 flows back to the oil storage tank. During this process, the pressure in the hydraulic chamber 302 drops, and the inner ring 303 is disengaged from the pile foundation under the action of elastic restoring force or external structure, and returns to the initial position until the reset is completed, at which point the hydraulic motor stops running.

[0042] It can be noted that the hydraulic chamber 302 is an annular piston cylinder or an expandable high-strength synthetic membrane.

[0043] For example, when the hydraulic chamber 302 is selected as an annular piston cylinder, its annular cavity is arranged in a ring along the circumference of the pile foundation 5 and can undergo elastic deformation so that when the pressure in the cavity is high, the inner ring 303 is driven to move radially inward (i.e., in the direction of the pile foundation 5).

[0044] Of course, the hydraulic chamber 302 can also be made entirely of a high-strength synthetic film with good sealing and expansion (elasticity), such as a high-performance thermoplastic polyurethane (TPU) film, which can ensure that the hydraulic chamber 302 expands and has the ability to provide friction lifting.

[0045] In one embodiment, such as Figure 1 , Figure 2 , Figures 4 to 7 As shown, the inner wall of the inner ring 303 is provided with an anti-slip protrusion 304 extending radially inward, which is used to abut against the outer wall of the pile foundation 5.

[0046] With this configuration, the inner wall of the inner ring 303 has a radially extending anti-slip protrusion 304. During use, the construction personnel can adjust the pressure inside the hydraulic chamber 302 as needed through the hydraulic drive component.

[0047] For example, when the hydraulic drive increases the pressure inside the hydraulic chamber 302, it drives the inner ring 303 to press against the pile foundation 5, increasing the equivalent friction coefficient of the contact section. This transforms the macroscopic sliding that might have occurred into the squeezing between the anti-slip protrusion 304 and the surface of the pile foundation 5, preventing relative slippage between the lifting mechanism 3 and the pile foundation 5 under the action of the pile pulling force.

[0048] It can be noted that, in this embodiment, the anti-slip protrusion 304 has a serrated texture (such as...). Figure 7 As shown), discrete card blocks (such as...) Figure 6 (as shown) or at least one of expandable friction pads.

[0049] Furthermore, its material is composed of at least one of high-strength synthetic film, high-strength alloy steel, and inlaid hard alloy.

[0050] Preferably, the anti-slip protrusion 304 is made of a high-strength synthetic membrane, a polymer liquid reaction curing elastic waterproof material based on organic and inorganic materials, compounded with polymer emulsion, active chemical substances and various additives, and is an environmentally friendly industrial product. This material is solvent-free and features non-toxicity, odorlessness, strong adhesion, good impermeability, and strong aging resistance.

[0051] In areas with high stress requirements, a DFZ (ethylene propylene diene monomer) polymer reinforcing layer is added for reinforcement.

[0052] It can be noted that the number of anti-slip protrusions 304 must meet the requirements of the sum of the weight of the jacking pile foundation 5 and the side friction resistance.

[0053] In one embodiment, such as Figures 1 to 3As shown, the connecting cylinder 1 includes a top cover 101 at one end opposite to the opening, and a drain hole 102 is provided on the top cover 101; the fluid drive 2 is connected to the drain hole 102 through an injection pipe.

[0054] With this configuration, by providing a drain hole 102 on the top cover 101 of the connecting cylinder 1 and using an injection pipe to connect the fluid drive component 2 and the drain hole 102, the suction path is ensured to be short and the flow resistance is small, thus shortening the time for a single sinking operation.

[0055] For example, when fluid is drawn into the drain hole 102, the pressure inside the fluid chamber drops rapidly, creating a negative pressure environment. At this time, seawater outside the connecting cylinder 1 enters the chamber through the sealed gap between the cylinder and the pile foundation 5, pushing the cylinder downwards until it is completely embedded in the soil around the pile foundation 5. When it is necessary to pull the connecting cylinder 1 upwards, the fluid drive unit 2 injects water into the top of the fluid chamber through the injection pipe and the drain hole 102. The water flow injected from the top can smoothly fill the chamber space, avoiding turbulence, cavitation, or local scouring of the seabed soil that may be caused by injection from the bottom. This allows the pressure inside the chamber to be restored to equilibrium with the environmental pressure evenly and controllably, reducing the adsorption force formed during sinking and preventing violent movement of the device due to sudden pressure release.

[0056] In one embodiment, such as Figures 1 to 4 , Figure 8 and Figure 9 As shown, the interior of the connecting cylinder 1 is provided with several partitions 103 to divide the fluid chamber into multiple independent adjustment chambers 104. Each adjustment chamber 104 is independently connected to the fluid drive component 2 and is used to adjust the verticality of the connecting cylinder 1 during the sinking or pulling process.

[0057] This configuration, by setting multiple independent adjustment chambers 104 in the fluid chamber of the connecting cylinder 1 and making each of them independently controllable by the fluid drive component 2, provides an active and adjustable leveling mechanism for the operation process, ensuring a balanced external force during sinking and pulling.

[0058] For example, when the connecting cylinder 1 sinks into the seabed, the penetration resistance on different sides of the cylinder will vary due to the unevenness of the seabed surface or the uneven hardness of the underlying soil. This can easily cause the cylinder to tilt. If the cylinder is detected to tilt to one side, the drainage of the compartment on that side can be reduced (i.e., the downward force on that side can be reduced), or the drainage of the compartment on the other side can be accelerated (i.e., the downward force on the other side can be increased). This will create a corrective torque at the bottom of the cylinder, achieving dynamic and active correction and ensuring that the connecting cylinder 1 always sinks to the predetermined depth with a very high degree of verticality, providing a stable and centered foundation for subsequent jacking operations.

[0059] It should be noted that there is no specific limit to the number of regulating compartments 104; they can be set as needed.

[0060] For example, it is divided into four cabins (such as...) Figure 8 As shown), six cabins (diagram omitted), eight cabins (as shown) Figure 9 (as shown in the image) etc.

[0061] Furthermore, adjacent compartments are connected by a connecting pipe, and the pressure difference between the inside and outside of different compartments is controlled by the fluid drive component 2, thereby achieving leveling.

[0062] In one embodiment, such as Figure 1 and Figure 2 As shown, the demolition device for pile foundations also includes a lifting lug 4, which is fixedly connected to the connecting cylinder 1 and used to connect the hoisting equipment 10.

[0063] This configuration, by adding lifting lug 4, provides a dedicated interface for the lifting and transfer of the dismantling device throughout its entire operational lifecycle. Compared to temporary binding or the use of non-standard clamps, the dedicated lifting lug 4 ensures that the lifting force is always applied to the predetermined position that has been structurally reinforced, avoiding the risk of structural damage, paint film damage, or even instability and fall caused by slippage of the lifting point or stress concentration, thus improving the safety of the lifting process.

[0064] Preferably, the hoisting equipment 10 is a crane.

[0065] In one embodiment, such as Figure 1 As shown, the demolition device for pile foundations also includes a hoisting steel cable 8, which connects the hoisting equipment 10 and the connecting cylinder 1 for lowering the connecting cylinder 1.

[0066] In one embodiment, such as Figure 1 As shown, the demolition device for pile foundations also includes a lifting device 9, which is used to connect the lifting steel cable 8 and the lifting equipment 10.

[0067] In one embodiment, such as Figure 1 As shown, the demolition device for the pile foundation also includes a vessel 11. The vessel 11 has a control cabin 12 and a hoisting device 10 on its deck. The control cabin 12 is used to control the hoisting device 10 to lower the connecting cylinder 1, or to control the hoisting of the connecting cylinder 1 and the pile foundation 5, or to control the installation of the connecting cylinder 1 in the water injection.

[0068] It can be explained that, for example Figure 1 As shown, the demolition device for pile foundations also includes a detection mechanism and a control terminal 7.

[0069] The testing equipment includes tilt testing components, pressure testing components, displacement testing components, and tensile testing components.

[0070] Specifically, the tilt angle detection device is used to monitor the tilt angle of the connecting cylinder 1 and / or pile foundation 5 in real time; the pressure detection device is used to monitor the pressure of the hydraulic chamber 302 and the inlet and outlet pressure of the fluid drive component 2 in real time; the displacement detection device is used to monitor the upward displacement of the connecting cylinder 1 and / or pile foundation 5 relative to the seabed in real time; and the tension detection device is installed on the hook of the lifting equipment to monitor the total upward pull force in real time.

[0071] Furthermore, the control terminal 7 is communicatively connected to and receives signals from the tilt detection device, pressure detection device, displacement detection device, and tension detection device, and the control terminal 7 is also communicatively connected to and receives signals from the fluid drive device 2 and the hydraulic drive device. The control terminal 7 is configured to perform at least one of the leveling control process, the lifting coordination process, and the emergency response process.

[0072] Specifically, the leveling control process is as follows: the data from the tilt angle detection device is received, and when the tilt angle is determined to exceed the first preset threshold, the fluid drive device 2 is controlled to perform differentiated suction or injection on multiple adjustment chambers 104 in the connecting cylinder 1 to adjust the pressure difference in each chamber, thereby correcting the verticality of the connecting cylinder 1. Specifically, the jacking coordination process involves receiving data from displacement and tension sensors, coordinating and controlling the clamping force applied to the pile foundation 5 by the jacking mechanism 3 and the water injection pressure of the fluid drive component 2, in order to achieve synchronous management of the upward pulling speed and total upward pulling force of the connecting cylinder 1. Specifically, the emergency response process is as follows: Upon receiving data from the tensile testing device, when it is determined that the total pull-out force has suddenly dropped and exceeded the second preset threshold, it is determined that the pile foundation 5 has suddenly loosened, and a pause command is immediately issued to the lifting equipment and the jacking mechanism 3 is controlled to maintain or adjust the clamping state.

[0073] It can be explained that the control terminal 7 can control the suction speed of the fluid drive component 2 to regulate the penetration and extraction of the connecting cylinder 1 during the demolition of the pile foundation 5; at the same time, it can control the hydraulic drive component to regulate the fixing and disengagement of the inner ring 303 and the pile foundation 5.

[0074] In the above embodiment, the demolition device for pile foundations uses a crane to install the fluid drive component 2 onto the drainage holes 102 on each connecting cylinder 1 during the installation of the connecting cylinder 1. Subsequently, the connecting cylinder 1 and its upper structure are lowered to the seabed using the hoisting equipment 10.

[0075] Preferably, each connecting cylinder 1 is equipped with a fluid drive component 2 on its top cover 101, and the connecting cylinder 1 can be stably and vertically inserted by adjusting the pumping rate of each fluid drive component 2.

[0076] During the gravity penetration stage, the pump valve of the fluid drive component 2 remains open, allowing the water inside the connecting cylinder 1 to be freely discharged through the drain hole 102 of the top cover 101 during the lowering process.

[0077] After the gravity penetration stage is completed, the fluid drive unit 2 is activated to pump water from inside the cylinder, creating a pressure difference between the inside and outside of the cylinder, which further penetrates the connecting cylinder 1.

[0078] During installation, operators monitor the installation of connecting cylinder 1 in real time. The drainage volume is measured by a flow meter, and the negative pressure suction value is calculated by two pressure sensors (one inside and one outside the cylinder). The penetration depth of connecting cylinder 1 is accurately determined using a GPS positioning system and an underwater robot.

[0079] It can be noted that all installation data, including time, flow rate, pressure value and penetration depth, are continuously recorded and transmitted to the operation control system via umbilical cable.

[0080] According to an embodiment of the present invention, on the other hand, such as Figure 10 As shown, a method for removing pile foundations is also provided, which is applied to the removal device for pile foundations provided in the former aspect.

[0081] Among them, such as Figure 10 As shown, the demolition methods for pile foundations include steps such as sinking, fixing, jacking, circulation, and hoisting.

[0082] Specifically: Sinking: Using hoisting equipment 10, the connecting cylinder 1 is lowered to the outside of the pile foundation 5 to be demolished, and the connecting cylinder 1 sinks into the seabed by its own weight and the negative pressure generated by the pumping of water by the fluid drive component 2.

[0083] Fixing: Activate the hydraulic drive unit to clamp the pile foundation 5.

[0084] Lifting: Start the fluid drive unit 2 to inject water into the connecting cylinder 1, causing the connecting cylinder 1 to be pulled up, which in turn drives the pile foundation 5 to be pulled up as a whole.

[0085] Cycle: Repeat the sinking, fixing and jacking steps until pile 5 is completely loosened.

[0086] Lifting: Use lifting equipment 10 to pull the connecting cylinder 1 and the pile foundation 5 out of the seabed as a whole.

[0087] This configuration allows for a negative pressure sinking mechanism during the sinking phase, utilizing the weight of the connecting cylinder 1 and the negative pressure generated by the pumping of water by the fluid drive component 2 to allow the connecting cylinder 1 to sink into the seabed. During the fixing phase, the hydraulic drive component clamps the pile foundation 5 without the need for diver intervention, and the clamping force can be dynamically adjusted. During the jacking phase, water is injected into the connecting cylinder 1, and the fluid pressure pushes the cylinder upwards, causing the pile foundation 5 to move as a whole, converting the fluid pressure into axial force. During the circulation phase, the adhesion between the pile foundation 5 and the seabed soil is gradually reduced by repeating the sinking, fixing, and jacking steps. Finally, during the lifting phase, the connecting cylinder 1 and the pile foundation 5 are pulled out of the seabed as a whole.

[0088] In other words, compared with the traditional pile cutting process that requires manual operation by divers, this method does not require cutting the pile body during the entire process, reducing the time and frequency of workers being exposed to high-risk environments, and avoiding the local damage to the pile body caused by traditional cutting operations, thereby reducing the risk of structural instability, reducing the need for secondary treatment due to local fracture of the pile foundation, and avoiding environmental risks such as water flow disturbance, insufficient visibility, and underwater organisms.

[0089] It can be observed that during the settling process, the soil exhibits different drainage characteristics at different shear rates, and the shear strength of the same soil differs under different drainage states. Therefore, different installation speeds during the self-weight penetration stage and the negative pressure penetration stage may lead to different drainage states, thereby affecting the penetration resistance of the soil.

[0090] For example, during the self-weight penetration stage, the connecting cylinder 1 penetrates at a relatively fast speed, and the clay and silt around the cylinder are in a non-drained state, while the sand may be in a partially drained state. However, during the negative pressure penetration stage, the connecting cylinder 1 penetrates at a relatively slow speed, and the clay around the cylinder foundation is in a non-drained state, the silt is in a partially drained state, while the sand may be completely drained.

[0091] In one embodiment, the sinking step includes: gravity penetration: relying on the weight of the connecting cylinder 1 to initially penetrate the seabed; suction penetration: activating the fluid drive 2 to draw fluid from the fluid chamber inside the connecting cylinder 1, using negative pressure suction to drive the connecting cylinder 1 to continue penetrating.

[0092] With this setup, by setting a self-weight penetration stage, the initial penetration is achieved by utilizing the self-weight of the connecting cylinder 1, without the need for additional energy consumption. This allows for rapid penetration of the soft soil on the seabed surface, providing a reference direction for subsequent suction penetration and reducing the risk of deviation caused by external disturbances (such as water flow).

[0093] Furthermore, by using the fluid drive component 2 to draw fluid from the chamber and create negative pressure, the penetration power and the sinking force of the cylinder are further enhanced, which can effectively overcome the resistance of rock strata or dense sand layers.

[0094] The phased strategy allows for dynamic switching of penetration modes based on geological profiles. For example, in alternating soft and hard layers, the soft layer can be penetrated by gravity first, and then the hard layer can be broken through by suction penetration, thus avoiding the inefficiency caused by a single mode.

[0095] It can be explained that during the suction penetration stage, the following equation needs to be satisfied: .

[0096] In the formula, W is the buoyant weight of the suction cylinder, DP is the suction value, i.e., the pressure difference, and R is the total resistance provided by the soil.

[0097] Preferably, the soil is divided during the self-weight penetration stage: the soil is divided into all depth ranges according to the lowering speed (v=3m / min) of the connecting cylinder 1 during the self-weight penetration stage. In this stage, silt, clay, and silt are all classified as undrained soil (UDS), while silt or sand is classified as partially drained soil (PDS).

[0098] Among them, determining the self-weight penetration depth involves calculating the penetration resistance curve using the corresponding parameters, and determining the penetration depth when the penetration resistance is equal to the buoyancy of the suction cylinder, i.e., the self-weight penetration depth.

[0099] Specifically, the relevant parameters include the measured self-weight penetration depth and the following formula:

[0100] In the formula: The buoyant weight (equal to the total resistance of the soil to the pile at the end of penetration) is expressed in kN. This represents the end drag coefficient at depth d, which is dimensionless and typically... =0.4, The cross-sectional area at the end of the cylinder, in meters. 2 , The cone tip resistance at depth d is the measured resistance in kPa, obtained from a static cone penetration test (CPT). This is a parameter representing the distribution of the pile's side surface area along its depth, which is equal to the sum of the circumferences of the inner and outer diameters. ), representing the surface area per unit depth. Let be the side resistance coefficient at depth z, which is dimensionless, and d be the pile's penetration depth. This is the integral of the cone tip resistance along the depth.

[0101] in, Indicates the pile end resistance. This represents the total resistance along the pile side.

[0102] Furthermore, the solution is obtained by inverse calculation using a linear equation in one variable. .

[0103] It should be noted that within the self-weight penetration depth range, all soil is undrained soil (UDS).

[0104] Preferably, the soil is divided during the suction penetration stage: the soil below the self-weight penetration depth is re-divided according to the lowering speed (v=3m / hr) of the connecting cylinder 1 during the suction penetration stage.

[0105] Further, calculate the required negative pressure suction: Based on the results of the previous soil re-division, select the corresponding design parameters and recalculate the penetration resistance below the self-weight penetration depth. Subtract the buoyancy weight from the penetration resistance to obtain the required negative pressure suction.

[0106] In one embodiment, the lifting step further includes: leveling: real-time monitoring of the tilt angle of the connecting cylinder 1, and when the tilt angle exceeds a preset threshold, controlling the fluid drive 2 to perform differentiated suction or injection on the multiple adjustment chambers 104 separated in the connecting cylinder 1 to adjust the pressure difference in each chamber, thereby correcting the verticality of the connecting cylinder 1.

[0107] With this setup, by monitoring the tilt angle in real time and adjusting the chamber 104 in a differentiated manner, once the tilt exceeds the preset threshold, a corrective torque is applied by adjusting the pressure of a specific chamber. This can actively counteract and offset unpredictable external asymmetrical loads, ensuring that the connecting cylinder 1 and the pile foundation 5 are always safely pulled up in the vertical direction, preventing jamming or even structural damage caused by increased tilt.

[0108] For example, if the cylinder tilts to the left, pressurize the left compartment (increase the support force) and release the pressure in the right compartment (reduce the resistance), forming a reverse torque to correct the tilt.

[0109] In one embodiment, the jacking step further includes: emergency control: real-time monitoring of the upward force of the pile foundation 5; when it is determined that the upward force has suddenly dropped and exceeded the preset safety threshold, it is determined that the pile foundation 5 has suddenly loosened, and at least one of the following operations is performed immediately: suspending the upward jacking of the hoisting equipment 10, adjusting the clamping state of the jacking mechanism 3, and adjusting the water injection pressure of the fluid drive component 2.

[0110] This setup, by collecting real-time data on the pull-out force of pile foundation 5 and comparing it with a preset safety threshold, determines that pile foundation 5 has suddenly loosened when a sudden drop in pull-out force is detected. The power source of the hoisting equipment 10 is immediately cut off to prevent the pile foundation 5 from breaking or the connecting cylinder 1 from being damaged due to continuous force application. Alternatively, the clamping pressure is quickly released via hydraulic drives, causing the inner ring 303 to disengage from the pile foundation 5, preventing the clamping force from transforming into destructive shear force due to the loosening of pile foundation 5. Furthermore, the pressure in each regulating chamber 104 is dynamically adjusted, prioritizing the release of pressure from the high-pressure side chambers to balance the cylinder's attitude and prevent equipment jamming or seabed collapse due to increased tilting. This multi-strategy coordinated emergency response effectively suppresses different forms of instability risks.

[0111] In one embodiment, prior to the sinking step, the following steps are also included: resistance estimation: based on geological survey data, the sum of the side friction resistance and gravity of the pile foundation 5 is calculated to estimate the minimum clamping force required by the lifting mechanism 3 and the minimum upward pulling pressure required by the fluid drive component 2.

[0112] This setup allows for the calculation of the sum of the side friction resistance and gravity of the pile foundation 5 based on geological surveys conducted before the sinking step. This precise quantification of the total resistance that needs to be overcome during jacking allows for the calculation of the minimum clamping force required by the jacking mechanism 3 (to overcome the side friction resistance of the pile foundation 5) and the minimum upward pulling pressure required by the fluid drive component 2 (to overcome the total resistance) based on the total resistance. This provides power selection guidance for each drive component, preventing insufficient clamping force from causing the pile foundation 5 to slip or insufficient upward pulling pressure from causing work stoppage, or preventing resource waste caused by over-design.

[0113] Furthermore, the resistance to dismantling pile 5 is equal to the sum of the weight of pile 5, the side friction of pile 5, the weight of connecting cylinder 1, and the side friction of connecting cylinder 1.

[0114] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A demolition device for a pile foundation, characterized in that, Comprise: The connecting cylinder (1) is in the form of an open-ended cylindrical structure, the connecting cylinder (1) is movably sleeved on the outer part of the pile foundation (5) at the end opposite to the opening, and the sleeving part is subjected to sliding sealing treatment, and an annular fluid chamber is formed between the inner wall of the connecting cylinder (1) and the outer wall of the pile foundation (5). The fluid driving element (2) is used to communicate with the fluid chamber to suck or inject fluid, and a pressure difference is formed between the inside and outside of the connecting cylinder (1) to control the sinking or pulling of the connecting cylinder (1). The jacking mechanism (3) is installed on the sleeving part and is used to be fixedly connected with the pile foundation (5) to drive the overall movement of the pile foundation (5).

2. The removal device for the pile foundation according to claim 1, wherein the jacking mechanism (3) comprises: An outer ring (301) is installed on the inner wall of the connecting cylinder (1) at the sleeving part; A hydraulic chamber (302) is arranged in the form of an annular structure and is located inside the outer ring (301); An inner ring (303) is connected with the hydraulic chamber (302) and is used to increase the contact area and friction with the outer wall of the pile foundation (5); A hydraulic driving element is used to adjust the hydraulic pressure in the hydraulic chamber (302) to drive the inner ring (303) to be tightly fixed with the pile foundation (5).

3. The removal device for the pile foundation according to claim 2, wherein the inner wall of the inner ring (303) is provided with anti-skid protrusions (304) extending in the radial direction, and the anti-skid protrusions (304) are used to abut against the outer wall of the pile foundation (5).

4. The removal device for the pile foundation according to any one of claims 1-3, wherein the end of the connecting cylinder (1) opposite to the opening comprises a top cover (101), and a drain hole (102) is formed in the top cover (101); The fluid driving element (2) is connected with the drain hole (102) through a suction and injection pipe element.

5. The removal device for the pile foundation according to any one of claims 1-3, wherein the inside of the connecting cylinder (1) is provided with a plurality of partitions (103) for separating the fluid chamber into a plurality of independent adjusting chambers (104), and each adjusting chamber (104) is independently connected with the fluid driving element (2) to adjust the perpendicularity of the connecting cylinder (1) during sinking or pulling. Further comprising: A lifting lug (4) is fixedly connected with the connecting cylinder (1) and is used to be connected with hoisting equipment (10). The removal method applied to the removal device for the pile foundation according to any one of claims 1-6 comprises the following steps: Sinking: The connecting cylinder (1) is lowered to the outside of the pile foundation (5) to be removed, and the self-weight of the connecting cylinder (1) and the negative pressure generated by the water suction of the fluid driving element (2) are used to sink the connecting cylinder (1) into the seabed; 6. A demolition device for a pile foundation according to any one of claims 1-3, characterized in that, Fixing: The hydraulic driving element is started to clamp the pile foundation (5); Jacking: The fluid driving element (2) is started to inject water into the connecting cylinder (1) to pull up the connecting cylinder (1) and drive the overall pulling up of the pile foundation (5).

7. A method for removal of a pile foundation, characterized in that, ​ ​ ​ ​ Circulation: repeat the sinking, fixing and jacking steps until the pile foundation (5) is completely loose; Hoisting: use the hoisting equipment (10) to pull out the connection cylinder (1) and the pile foundation (5) from the seabed as a whole.

8. The method for removing a pile foundation according to claim 7, wherein, The sinking step comprises: Self-weight penetration: rely on the self-weight of the connection cylinder (1) to initially penetrate the seabed; Suction penetration: start the fluid driving member (2) to suck the fluid in the internal fluid chamber of the connection cylinder (1) to drive the connection cylinder (1) to continue to penetrate by negative pressure suction.

9. The method for removing a pile foundation according to claim 7, wherein, The jacking step further comprises: Leveling: real-time monitor the inclination angle of the connection cylinder (1), when the inclination angle exceeds the preset threshold, control the fluid driving member (2) to differentially suck or inject the multiple adjustment chambers (104) separated in the connection cylinder (1) to adjust the pressure difference in each chamber, so as to correct the perpendicularity of the connection cylinder (1).

10. The method for removing a pile foundation according to claim 7, wherein, The jacking step further comprises: Emergency control: real-time monitor the pulling force of the pile foundation (5), when it is judged that the pulling force suddenly drops and exceeds the preset safety threshold, it is judged that the pile foundation (5) has suddenly loosened, and at least one of the following operations is immediately executed: suspend the pulling of the hoisting equipment (10), adjust the clamping state of the jacking mechanism (3), adjust the water injection pressure of the fluid driving member (2).

11. The method for removing a pile foundation according to claim 7, wherein, Before the sinking step, further comprising: Resistance estimation: based on the geological survey data, calculate the sum of the side friction and gravity of the pile foundation (5) to estimate the minimum clamping force required by the jacking mechanism (3) and the minimum pulling pressure required by the fluid driving member (2).

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