Construction method for efficiently and losslessly pulling out offshore pile foundation

Abstract

The invention discloses an offshore pile foundation efficient lossless pulling construction method which comprises the steps of early-stage preparation, pretreatment of soil around a pile, pile pulling operation, pile hoisting and storage and the like, the soil around the pile is pretreated through a high-pressure injection system and a vibration generation device, pile pulling resistance is reduced, and pile pulling efficiency is improved. The special device comprises a ship body supporting system, a high-pressure injection system, a vibration generating device, a clamping mechanism, lifting equipment, a monitoring control system and the like. The problems that in an existing offshore pile pulling technology, efficiency is low, the equipment requirement is high, the influence on the environment is large, and safety is poor can be solved, efficient, safe and environment-friendly operation of offshore pile pulling is achieved, and remarkable economic benefits and social benefits are achieved.

Description

Technical Field

[0001] This invention relates to the field of marine engineering construction technology, specifically to a method for efficient and non-destructive removal of marine pile foundations, applicable to the removal of various pile foundations in projects such as offshore wind power, cross-sea bridges, and offshore platforms. Background Technology

[0002] In offshore engineering construction, such as offshore wind power, cross-sea bridges, and offshore platforms, pile driving is a common foundation construction method. However, when the project is completed or adjustments to the pile foundation are needed, pile extraction becomes a crucial step. Traditional offshore pile extraction methods have several problems, such as: Inefficient: Conventional pile extraction processes often require a lot of time, especially when the piles are deeply embedded in the soil or the geological conditions are complex. Each pile extraction operation may take several days or even weeks, which seriously affects the progress of the project. High equipment requirements: In order to overcome the friction and adsorption forces between the pile and the soil, large, high-power lifting equipment and auxiliary devices are usually required. This not only increases the cost of equipment, but also places extremely high demands on the performance and stability of the construction vessel. Significant impact on the surrounding environment: During the pile extraction process, the large force required may cause disturbance to the surrounding soil, leading to local collapse or deformation of the seabed, which may have an adverse impact on the marine ecological environment and other nearby facilities. Poor safety: The complex marine environment and the highly difficult pile extraction operation make the construction process involve high safety risks, such as equipment failure, pile fracture, and ship tilting, which may endanger the lives of construction personnel. Existing technical documents, such as patent (CN106320340B), disclose a high-pressure water jetting pile extraction process. However, this method is mainly applicable to the extraction of old pile foundations on land and is not designed for the special characteristics of the marine environment. It lacks solutions to problems such as seawater corrosion and the high fluidity of seabed soil. Direct application at sea would result in poor pile extraction stability and a large area of ​​soil disturbance. Furthermore, the high-pressure water jetting parameters of this technology are fixed and cannot be flexibly adjusted according to complex geological conditions at sea. Moreover, it lacks environmental protection measures, easily causing marine pollution. Patent (CN120465469A) discloses a method for extracting test piles for offshore photovoltaic systems. However, this method is mainly for prestressed high-strength concrete pipe pile test piles. The process is complex, requiring the installation of hydraulic cutting units for segmented cutting. This not only results in high construction costs but also makes it difficult to completely recover the debris generated during the cutting process, easily polluting the marine environment. In addition, this method has strict requirements for the positioning of construction vessels, using a T-shaped positioning method, which is complex and unsuitable for large-scale offshore pile extraction operations. Furthermore, it does not consider soil pretreatment optimization under different geological conditions, limiting the efficiency of pile extraction.

[0003] In conclusion, existing offshore pile extraction technologies are insufficient to meet the requirements of efficient, safe, and environmentally friendly construction in modern offshore engineering, and there is an urgent need for a new method for efficient and non-destructive removal of offshore pile foundations. Summary of the Invention

[0004] The purpose of this invention is to provide an efficient and non-destructive method for removing marine pile foundations, so as to solve the problems of low efficiency, high equipment requirements, large environmental impact and poor safety in the existing technology.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for efficient and non-destructive removal of marine pile foundations includes the following steps: Step 1: Preliminary preparation, determining the location, specifications, and geological conditions of the pile to be removed, and selecting a construction vessel and specialized equipment based on this information; installing and debugging the specialized pile removal equipment on the construction vessel to ensure that all components of the equipment function normally; Step 2: Pre-treatment of the soil around the pile, using the high-pressure jetting system in the specialized equipment to inject high-pressure water or high-pressure gas-liquid mixture into the soil around the pile, forming a jet in the soil, disrupting the structure of the soil around the pile, and reducing the friction and adsorption force of the soil on the pile; Step 3: Pile removal operation, firmly connecting the clamping mechanism in the specialized pile removal equipment to the top of the pile, starting the lifting equipment on the construction vessel, gradually applying upward pulling force, monitoring the pile parameters in real time during the lifting process, and continuously using the high-pressure jetting system to supplement the spraying of the soil around the pile; Step 4: Lifting and storage of the pile, after the pile is completely removed, using the lifting equipment on the construction vessel to lift the pile to a designated location for storage or subsequent processing.

[0006] Furthermore, in step one, protective facilities are set up around the pile to be removed to prevent debris from falling and polluting the marine environment during the pile removal process.

[0007] Furthermore, in step two, the injection pressure of the high-pressure injection system is controlled between 2MPa and 3MPa, and the injection angle is within the range of 0° to 65°, and is adjusted in real time according to geological conditions and the depth of the pile penetration.

[0008] Furthermore, in step two, for harder soil layers or situations with large obstacles, the vibration generator in the special device is activated to cause the pile body to vibrate at a certain frequency and amplitude, further loosening the soil around the pile.

[0009] Furthermore, in step three, the real-time monitored pile parameters include pile displacement, verticality, and tension changes. When the monitored parameters exceed the preset threshold, the lifting speed and tension are automatically adjusted.

[0010] Furthermore, the clamping mechanism in step three adopts a double-clamp structure, and the opening, closing and locking of the clamps are achieved by hydraulic drive.

[0011] Furthermore, during the hoisting process in step four, necessary fixing and protective measures should be taken to prevent the pile from shaking or colliding.

[0012] The beneficial effects of this invention are: 1. Improve pile extraction efficiency: By pre-treating the soil around the pile through a high-pressure jetting system and a vibration generator, the resistance to pile extraction is greatly reduced, making the pile extraction process smoother and significantly shortening the extraction time. Compared with traditional processes, the efficiency is significantly improved. 2. Reduced Equipment Requirements: By reducing pile extraction resistance, the power and lifting capacity requirements of the hoisting equipment are lowered, allowing for the use of smaller construction vessels and equipment, thus reducing equipment procurement and leasing costs. Furthermore, the relatively simple structure of the device facilitates installation and commissioning, further saving construction preparation time and costs. 3. Reduced environmental impact: During pile extraction, precise treatment and control of the soil around the piles reduced the area of ​​soil disturbance, thus minimizing damage to the marine ecosystem. Simultaneously, the installation of protective facilities effectively prevented debris from falling and avoided pollution of marine life and water quality. 4. Improved Construction Safety: The monitoring and control system can monitor various parameters during the construction process in real time, promptly detect and handle abnormalities, and avoid safety accidents caused by equipment failure or improper operation. Furthermore, each component of the device has been carefully designed and strength-tested, possessing high reliability and stability, providing a safer working environment for construction personnel. Detailed Implementation

[0013] The present invention will be further described in detail below with reference to specific embodiments: The present invention provides a method for efficient and non-destructive removal of marine pile foundations, comprising the following steps: Step 1: Preliminary Preparations Determine the location, specifications, and geological conditions of the piles to be extracted, and select appropriate construction vessels and specialized equipment based on this information. Install and test the specialized pile extraction device on the construction vessel to ensure that all components function properly. Set up protective facilities around the pile to be extracted to prevent debris from falling and polluting the marine environment during the extraction process. Step 2: Pretreatment of the soil around the pile Using a specialized high-pressure jetting system, high-pressure water or a high-pressure gas-liquid mixture is injected into the soil around the pile. This high-pressure water or gas-liquid mixture forms a jet within the soil, disrupting the structure of the soil surrounding the pile and reducing the friction and adhesion between the soil and the pile. The jetting angle and pressure can be adjusted according to geological conditions and the pile's depth. Generally, the jetting pressure is controlled between 2 MPa and 3 MPa, and the jetting angle is within the range of 0° to 65°. For harder soil layers or situations with large obstacles, vibration-assisted methods can be used. Activate the vibration generator in the specialized device to cause the pile to vibrate at a certain frequency and amplitude, further loosening the soil around the pile. Step 3: Pile Extraction Operation The clamping mechanism in the pile extraction device (including the hull support system, high-pressure jetting system, vibration generator, and clamping mechanism) is firmly connected to the top of the pile to ensure that the connection can withstand the tensile force required for pile extraction. The lifting equipment on the construction vessel is activated, and through the coordinated action of the lifting equipment and specialized devices, an upward pulling force is gradually applied. During the lifting process, the displacement, verticality, and tension changes of the pile are monitored in real time. Based on the monitoring data, the lifting speed and tension are adjusted to ensure a smooth pile extraction process. During pile extraction, a high-pressure jetting system is continuously used to supplement the soil around the pile to maintain its loose state and reduce extraction resistance. Step 4: Lifting and storing the piles Once the pile is fully extracted, it is lifted to a designated location for storage or further processing using the hoisting equipment on the construction vessel. During the hoisting process, necessary securing and protective measures are taken to prevent the pile from swaying or colliding.

[0014] This invention effectively solves many problems of existing technologies through targeted process design, and realizes efficient, safe and environmentally friendly removal of offshore pile foundations, which has significant practical value and promotion significance.

Claims

1. A method for efficient and non-destructive removal of marine pile foundations, characterized in that, Includes the following steps: Step 1: Preliminary Preparation. Determine the location, specifications, and geological conditions of the pile to be extracted. Based on this information, select the construction vessel and specialized equipment. Install and debug the specialized pile extraction equipment on the construction vessel, ensuring that all components function properly. Step 2: Soil Pretreatment Around the Pile. Utilize the high-pressure jetting system in the specialized equipment to inject high-pressure water or a high-pressure gas-liquid mixture into the soil around the pile. The high-pressure water or gas-liquid mixture forms a jet in the soil, disrupting the structure of the soil around the pile and reducing the friction and adhesion between the soil and the pile. Step 3: Pile Extraction Operation. Securely connect the clamping mechanism in the specialized pile extraction equipment to the top of the pile. Start the lifting equipment on the construction vessel, gradually applying upward pulling force. Monitor the pile parameters in real time during the lifting process, and continuously supplement the surrounding soil with high-pressure jetting. Step 4: Pile Lifting and Storage. After the pile is completely extracted, use the lifting equipment on the construction vessel to lift the pile to a designated location for storage or further processing.

2. The efficient and non-destructive extraction method for offshore pile foundations according to claim 1, characterized in that, In step one, protective facilities are set up around the pile to be removed to prevent debris from falling and polluting the marine environment during the pile removal process.

3. The efficient and non-destructive extraction method for offshore pile foundations according to claim 1, characterized in that, In step two, the injection pressure of the high-pressure injection system is controlled between 2MPa and 3MPa, and the injection angle is within the range of 0° to 65°, and is adjusted in real time according to geological conditions and the depth of the pile.

4. The efficient and non-destructive extraction method for offshore pile foundations according to claim 1, characterized in that, In step two, for harder soil layers or situations with large obstacles, the vibration generator in the special device is activated to cause the pile to vibrate at a certain frequency and amplitude, further loosening the soil around the pile.

5. The efficient and non-destructive extraction method for offshore pile foundations according to claim 1, characterized in that, In step three, the real-time monitored pile parameters include pile displacement, verticality, and tension changes. When the monitored parameters exceed the preset threshold, the lifting speed and tension are automatically adjusted.

6. The efficient and non-destructive extraction method for offshore pile foundations according to claim 1, characterized in that, The clamping mechanism in step three adopts a double clamp structure, and the clamps are opened, closed and locked by hydraulic drive.

7. The efficient and non-destructive extraction method for offshore pile foundations according to claim 1, characterized in that, During the hoisting process in step four, necessary fixing and protective measures should be taken to prevent the pile from shaking or colliding.