Shallow sea floating platform pure FRP cable mooring segmented weight self-adaptive self-sensing anchoring system

Abstract

The utility model belongs to the technical field of oceanographic engineering and floating platform mooring, and discloses a shallow sea floating platform pure FRP cable mooring segmented weight self-adaptive self-sensing anchoring system and a construction method of the shallow sea floating platform pure FRP cable mooring segmented weight self-adaptive self-sensing anchoring system. And the mooring rope is made of an FRP material, so that the mooring rope is light in weight, high in strength and excellent in corrosion resistance. By designing a segmented ballasting scheme that balancing weights with different weights are arranged at different water depth positions, the problem that the mooring rigidity is insufficient due to the fact that the mass of the FRP cable is light is effectively solved, self-adaptive tension adjustment is achieved, and tidal changes and complex sea conditions can be effectively coped with; in addition, a clump weight mass selection formula suitable for shallow sea floating platforms with different masses under different water depth conditions is further designed, and reasonable selection of the mass of the clump weight is facilitated. Due to the design of the clamp, the shear stress concentration of the suspension position of the balancing weight is reduced, and the reliability of the system is improved. The FRP cable is embedded into the penetrating type optical fiber sensor, real-time stress monitoring of the mooring system is achieved, and data support and an early warning mechanism are provided.

Description

Technical Field

[0001] The utility model relates to the technical fields of ocean engineering and mooring technology for floating platforms, and particularly relates to a pure FRP cable mooring segmented ballast self-adaptive self-sensing anchoring system for a shallow sea floating platform. Background Technique

[0002] With the continuous deepening of ocean development, shallow sea floating platforms have been widely used in the fields of ocean energy development, ocean aquaculture, ocean tourism, etc. The traditional mooring system for floating platforms mainly relies on steel anchor chains for fixation. Although steel anchor chains have high strength and good tensile properties, there are some significant defects in actual applications.

[0003] Firstly, steel anchor chains are prone to corrosion in the marine environment, especially in seawater with a high salinity, and the corrosion problem is more serious. This corrosion not only affects the service life of the anchor chain but also greatly reduces the mooring stability of the floating platform, increasing the risk of platform operation. Secondly, the weight of the steel anchor chain is large, which brings inconvenience to the transportation, installation, and maintenance of the floating platform. In addition, with the development of ocean engineering towards intelligence and automation, higher requirements are put forward for the mooring system of floating platforms. The traditional steel anchor chain system is difficult to integrate fiber optic sensors and cannot monitor the force on the anchor chain in real time, which increases the operation and maintenance costs and makes it difficult to detect and handle potential safety hazards in a timely manner.

[0004] As a new type of material, FRP (fiber reinforced polymer) is gradually applied to civil engineering structures such as bridge cables. FRP cables have advantages such as high specific modulus, high specific strength, corrosion resistance, moisture absorption resistance, and fatigue resistance, and possess the basic elements for application in mooring cables of ocean floating platforms. At the same time, the structure and good dielectric properties of FRP materials make it more convenient to embed and integrate sensors, and it is more convenient to realize the force monitoring of the mooring system. However, due to the light weight of FRP cables, there is a deficiency in providing mooring tension, and it is difficult to ensure the stability of the platform in severe sea conditions.

[0005] Therefore, it is urgent to develop a new type of mooring system to solve the problems of insufficient corrosion resistance, difficult to maintain mooring tension, lack of force monitoring, and insufficient stability in complex sea conditions in the prior art. Content of the Utility Model

[0006] The utility model provides a pure FRP cable mooring segmented ballast self - adaptive self - sensing anchoring system for a shallow - water floating platform. The main innovation lies in designing a segmented ballast scheme for the FRP (fiber - reinforced polymer) mooring cables of the shallow - water floating platform, effectively solving the problems of the light weight and insufficient mooring stiffness of the FRP cables, significantly improving the durability of the mooring system, as well as the stability and self - adaptability of the floating platform. Moreover, optical fiber sensors are embedded in the FRP cables, providing a solid foundation for constructing a self - sensing mooring system for real - time force monitoring.

[0007] The technical solution of the utility model is as follows: A pure FRP cable mooring segmented ballast self - adaptive self - sensing anchoring system for a shallow - water floating platform, comprising: a shallow - water floating platform 1, a fairlead 2, an anchoring foundation 3, FRP cables 4, clamps 5, shackles 6, and ballast blocks 7; the fairlead 2 is arranged on the shallow - water floating platform 1; one end of the FRP cable 4 is connected to the shallow - water floating platform 1 through the fairlead 2, and the other end is connected to the anchoring foundation 3; several clamps 5 and several shackles 6 are arranged on each FRP cable 4; the ballast block 7 is installed on the FRP cable 4 through the clamp 5 and the shackle 6; the clamp 5 includes a splint 8 and a bolt 9, the splint 8 is square, and is divided into a top plate and a bottom plate; the top plate and the bottom plate are clamped on the FRP cable 4, having a large area to reduce the shear stress concentration at the hanging position of the ballast block 7.

[0008] The shackle 6 is connected below the bottom plate.

[0009] The FRP cable 4 includes several FRP single ribs 10, optical fiber sensors 11, a lock body sheath 12, an equal - stiffness filling material 13, and a joint 14; the number of the optical fiber sensors 11 is 4, symmetrically embedded between multiple layers of the FRP cable 4, and distributed along the entire length of the FRP cable to comprehensively, continuously, and accurately monitor the stress, strain, and temperature physical quantities at different positions of the FRP cable.

[0010] The FRP cable 4 is made of CFRP, GFRP, BFRP, or AFRP material.

[0011] The joint 14 of the FRP cable 4 adopts an end - encapsulation technology to prevent the colloid inside the end joint from peeling off, reduce the stress concentration in the connection area, ensure the connection strength and durability, and meet the dual requirements of function and strength. The equal - stiffness filling material 13 is epoxy resin or polyurethane.

[0012] The anchoring foundation 3 is a steel suction bucket or an FRP - reinforced concrete pile.

[0013] The counterweight block 7 includes multiple - stage counterweights, that is, the masses of the counterweight blocks suspended at different water depths are different. The requirements for the counterweight of the counterweight block 7 are as follows: counterweight blocks with different masses are suspended at different water depths, with lighter counterweight blocks arranged in the upper layer and heavier counterweight blocks arranged in the lower layer, so that the system can effectively cope with tidal changes and sea - state changes and reduce the stress on the anchoring foundation; the counterweight block 7 is made of corrosion - resistant materials, which are concrete or steel, and its structural form is spherical, cylindrical or cubic.

[0014] The beneficial effects of the present utility model are as follows:

[0015] (1) Improve corrosion resistance and service life: Using FRP material as the mooring cable significantly enhances the corrosion - resistant performance of the system, is especially suitable for the marine environment, extends the service life of the mooring system, and reduces the maintenance cost.

[0016] (2) Lightweight and high - strength, easy to install: The FRP cable is lighter than the traditional steel anchor chain, which is convenient for transportation and installation. At the same time, the design of segmented ballast provides the necessary mooring tension, ensuring the stability and safety of the system.

[0017] (3) Adaptive tension, enhance platform stability: By setting counterweight blocks with different weights at different depths of the FRP cable, the system can automatically adjust the tension according to the water depth and tidal changes, reduce the stress on the anchoring foundation, and thus significantly improve the stability of the floating platform under tidal changes and complex sea conditions.

[0018] (4) Force monitoring, improve safety: The fiber - optic sensors embedded in the FRP cable can real - time monitor the stress condition of the mooring system, greatly enhancing the safety and reliability of the system.

[0019] Generally speaking, the mooring system of the present utility model not only overcomes multiple problems in the traditional technology, but also realizes the mooring of a shallow - sea floating platform with high efficiency, stability, corrosion resistance and self - perception through innovative design, and has significant application value and promotion prospects. Brief Description of the Drawings

[0020] Figure 1 is a schematic diagram of the pure - FRP - cable mooring segmented - ballast adaptive self - perception anchoring system for a shallow - sea floating platform of the present utility model.

[0021] Figure 2 is a front - view schematic diagram of the pure - FRP - cable mooring segmented - ballast adaptive self - perception anchoring system for a shallow - sea floating platform of the present utility model. The upper dotted line represents the sea level, and the lower thick solid line represents the seabed.

[0022] Figure 3 is a top - view schematic diagram of the pure - FRP - cable mooring segmented - ballast adaptive self - perception anchoring system for a shallow - sea floating platform of the present utility model.

[0023] Figure 4 It is a schematic diagram of the anchoring foundation and the bottom counterweight block of the pure FRP cable mooring segmented ballast adaptive self-sensing anchoring system for the shallow water floating platform of the present utility model.

[0024] Figure 5 It is a schematic diagram of the hanging position of the counterweight block of the pure FRP cable mooring segmented ballast adaptive self-sensing anchoring system for the shallow water floating platform of the present utility model.

[0025] Figure 6 It is a schematic diagram of the fixture of the pure FRP cable mooring segmented ballast adaptive self-sensing anchoring system for the shallow water floating platform of the present utility model.

[0026] Figure 7 It is a schematic diagram of the shackle of the pure FRP cable mooring segmented ballast adaptive self-sensing anchoring system for the shallow water floating platform of the present utility model.

[0027] Figure 8 It is a schematic diagram of the encapsulated end of the FRP cable of the pure FRP cable mooring segmented ballast adaptive self-sensing anchoring system for the shallow water floating platform of the present utility model.

[0028] Figure 9 It is a cross-sectional schematic diagram of the FRP cable embedded with an optical fiber sensor in the pure FRP cable mooring segmented ballast adaptive self-sensing anchoring system for the shallow water floating platform of the present utility model.

[0029] In the figure: 1 - Shallow water floating platform; 2 - Fairlead; 3 - Anchoring foundation; 4 - FRP cable; 5 - Fixture; 6 - Shackle; 7 - Counterweight block; 8 - Splint; 9 - Bolt; 10 - FRP single bar; 11 - Optical fiber sensor; 12 - Lock body sheath; 13 - Equal stiffness filling material; 14 - Joint. Specific embodiments

[0030] The following further describes the present utility model in conjunction with the accompanying drawings and specific embodiments.

[0031] A pure FRP cable mooring segmented ballast adaptive self-sensing anchoring system for a shallow water floating platform includes: a shallow water floating platform 1, a fairlead 2, an anchoring foundation 3, an FRP cable 4, a fixture 5, a shackle 6, and a counterweight block 7.

[0032] The top of the FRP cable 4 is connected to the shallow water floating platform 1 through the fairlead 2. The fairlead 2 is used to guide the FRP cable and ensure uniform force during the connection process. The bottom of the FRP cable 4 is connected to the anchoring foundation 3. The anchoring foundation 3 can be a steel suction bucket or an FRP reinforced concrete pile, and the specific selection depends on the environmental conditions of the shallow sea and the load requirements of the platform.

[0033] The FRP cable 4 is made of CFRP, GFRP, BFRP or AFRP, all of which have excellent corrosion resistance and the characteristics of being lightweight and high-strength. The internal structure of the FRP cable includes FRP single bars 10, fiber optic sensors 11, lock body sheaths 12, equal stiffness filling materials 13 and joints 14. Four fiber optic sensors 11 are embedded in the FRP cable in a through manner to continuously monitor changes in stress, strain, etc. at different positions, ensuring the health and safety of the mooring system.

[0034] The fixture 5 is fixed at each segmented part of the FRP cable 4. The fixture consists of clamping plates 8 and bolts 9. The clamping plates 8 are designed to have a larger area to reduce the shear stress concentration caused by the hanging of the counterweight 7, thereby improving the reliability of the system. The counterweight 7 is suspended on the fixture 5 through a shackle 6.

[0035] The counterweight 7 is designed with a multi-stage counterweight method, that is, the masses of the counterweights suspended at different water depths are different. Lighter counterweights are suspended at the upper water depth positions, while heavier counterweights are suspended at the lower positions. This graded ballasting design can effectively cope with tidal changes and sea condition changes, maintain the stability of the platform, and reduce the stress borne by the anchoring foundation 3.

[0036] The anchoring foundation 3 can be a steel suction bucket or an FRP reinforced concrete pile. The steel suction bucket is suitable for deep sea or high load conditions and has excellent anchoring ability; the FRP reinforced concrete pile is suitable for shallow sea environments and has good durability and low cost.

[0037] There are 4 fiber optic sensors 11, which are arranged in a through manner and are usually embedded between multiple layers of the FRP cable, distributed along the entire length of the FRP cable. Through this layout, it is possible to comprehensively, continuously and accurately monitor physical quantities such as stress, strain and temperature at different positions of the FRP cable, avoiding blind spots caused by local monitoring. The multi-point arrangement of the fiber optic sensors also ensures the redundancy of the system. Even if a single sensor is damaged, other sensors can still maintain real-time monitoring of the system, avoiding the overall failure of the monitoring system. At the same time, this arrangement method embeds the sensors between the material layers, effectively protecting the sensors from damage by the external environment, such as seawater corrosion and mechanical impact, ensuring the long-term reliability of the sensors and the stability of the system.

[0038] The design of this utility model needs to consider the following factors:

[0039] (1) Marine environmental conditions: The design of the mooring system of this utility model needs to fully consider various factors in the shallow sea environment, including water depth, tidal changes, sea current speed, wave intensity, etc. These environmental conditions will directly affect the design parameters of the mooring system, such as the material selection of the FRP cable, the graded configuration of the counterweights, and the selection of the anchoring foundation. Through comprehensive analysis of the environmental conditions, the stability and safety of the system under various sea conditions can be ensured.

[0040] (2) Construction and maintenance conditions: The environmental conditions at the construction site, such as water depth and seabed properties, directly affect the formulation of the construction plan. Therefore, it is necessary to evaluate the site conditions in detail to ensure the smooth progress of the construction process. The transportation and installation of equipment are also important links, and it is necessary to ensure that equipment such as FRP cables and counterweights can be transported to the site efficiently and safely and installed correctly. At the same time, the maintainability of the system also needs to be considered. Selecting components that are easy to maintain and replace helps to reduce long-term maintenance costs.

[0041] (3) Economy and cost control: On the premise of ensuring system performance, the design needs to consider the cost-effectiveness of material selection, manufacturing process and construction method. Although FRP materials have excellent performance, their cost is relatively high. Therefore, it is necessary to allocate resources reasonably in the design, optimize the overall cost of the system, and improve the economy of the system.

[0042] (4) Laws, regulations and safety: The system design and construction must comply with relevant maritime laws and regulations and standards to ensure its legality and compliance. At the same time, the requirements of marine environmental protection also need to be taken seriously. Selecting environmentally friendly materials and processes can reduce the impact on the marine ecosystem. Safety guarantee is an important factor that cannot be ignored. The design and construction of the system must have sufficient safety measures to prevent accidents and ensure the safety of personnel and equipment.

[0043] (5) Usage requirements and functionality: The specific use of the floating platform (such as oil and gas exploitation, mariculture, etc.) determines the direction of system design and must meet the functional requirements of the platform. The adaptability of the system is also crucial, and it is necessary to ensure that it can operate normally in different sea areas and environments and has a wide range of applications. Scalability provides guarantee for future possible expansion needs. Designing a scalable system is convenient for later transformation and upgrading, thus improving the practicality and flexibility of the system.

[0044] Designing and implementing the construction and installation process of a pure FRP cable mooring segmented ballast adaptive self-sensing anchoring system for a shallow-water floating platform is a detailed and complex process involving multiple key steps. The following is the general construction and installation process of this system:

[0045] Before construction, it is first necessary to conduct a comprehensive survey of the shallow-water construction site to determine key parameters such as water depth, tidal changes, and seabed geological conditions to provide data support for the installation of the system. Prepare the equipment and materials required for construction according to the survey results, including FRP cables integrated with fiber optic sensors, counterweights, clamps, anchoring foundations, fairleads, etc.

[0046] After that, according to the design plan, the anchoring foundation (such as a steel suction bucket or an FRP reinforced concrete pile) is transported to the construction site. The positioning equipment is used to accurately determine the installation position of the anchoring foundation. Special equipment is used to fix the anchoring foundation on the seabed to ensure its stability and verticality. For the steel suction bucket, it can be fixed on the seabed through a suction device; for the FRP reinforced concrete pile, it can be installed by pile driving or pre-drilling.

[0047] Subsequently, the shallow-water floating platform 1 is positioned to the predetermined position by towing, and the FRP cable 4 with the fiber optic sensor 11 is gradually guided towards the anchoring foundation 3 through the fairlead 2. During this process, the clamps 5 are installed in sequence, and the counterweight blocks 7 are suspended at the predetermined positions of the FRP cable 4 through the shackles 6, ensuring that lighter counterweight blocks are suspended at the upper water depth position and heavier counterweight blocks are suspended at the lower position.

[0048] The FRP cable 4 is gradually guided towards the anchoring foundation through the fairlead 2, and finally the bottom of the FRP cable 4 is connected to the anchoring foundation 3 to ensure that the tension distribution of the entire system is uniform and meets the design requirements. After the installation is completed, the system is debugged and tested to ensure that all connection parts are firm and the system can operate normally under different sea conditions.

[0049] Through the above construction and installation process, the mooring system of the present utility model can be put into use efficiently and stably, and exhibits excellent performance and reliability in the complex shallow-water environment.

[0050] In a specific embodiment of the present utility model, the mass of the counterweight block 7 of the shallow-water floating platform 1 with different masses under different water depth conditions is determined by the following formula:

[0051] M total = M upper + M lower = k t W platform 1)

[0052] Wherein, M total is the total mass of the counterweight block; M upper , M lower are the masses of the upper and lower counterweight blocks respectively; W platform is the mass of the shallow-water floating platform; k t is the proportionality coefficient, usually between 0.1 and 0.3 (specifically determined according to the project requirements and design).

[0053] Then we distribute this total mass proportionally to the upper and lower counterweight blocks. The following distribution scheme can be considered:

[0054]

[0055] Wherein, H upper, H lower are the suspension water depths of the upper and lower counterweights respectively; k u and k l are coefficients used to adjust the ratio of the upper and lower counterweights, satisfying k u + k l = 1. Usually, k u can take values from 0.3 to 0.4, and k l can take values from 0.6 to 0.7 to ensure that the lower counterweight is heavier.

[0056] Through this design and formula calculation, it can be ensured that the masses of the upper and lower counterweights are adapted to the weight of the floating platform and the water depth, ensuring the stability and safety of the floating platform under different water depth conditions.

Claims

1. A pure FRP cable mooring segmented weight adaptive self-sensing anchoring system for shallow water floating platforms, characterized in that: The shallow-water floating platform pure FRP cable mooring segmented weight adaptive self-sensing anchoring system comprises: a shallow-water floating platform (1), a fairlead (2), an anchor foundation (3), an FRP cable (4), a clamp (5), a shackle (6) and a counterweight (7); the fairlead (2) is arranged on the shallow-water floating platform (1); one end of the FRP cable (4) is connected to the shallow-water floating platform (1) through the fairlead (2), and the other end is connected to the anchor foundation (3); a plurality of clamps (5) and a plurality of shackles (6) are arranged on each FRP cable (4); the counterweight (7) is installed on the FRP cable (4) through the clamp (5) and the shackle (6); the clamp (5) comprises a clamp plate (8) and a bolt (9); the clamp plate (8) is square and is divided into a top plate and a bottom plate; the top plate and the bottom plate are clamped on the FRP cable (4); the bottom of the bottom plate is connected to the shackle (6).

2. According to claim 1, the shallow-water floating platform pure FRP cable mooring segmented weight adaptive self-sensing anchoring system is characterized in that: The FRP cable (4) comprises a plurality of FRP single bars (10), optical fiber sensors (11), a lock body sheath (12), an equal-rigidity filling material (13) and a joint (14); the optical fiber sensors (11) are four in number and are symmetrically embedded between a plurality of layers of the FRP cable (4) and distributed along the entire length of the FRP cable, so as to comprehensively, continuously and accurately monitor the physical quantities of stress, strain and temperature at different positions of the FRP cable.

3. According to claim 2, the shallow-water floating platform pure FRP cable mooring segmented weight adaptive self-sensing anchoring system is characterized in that: The FRP cable (4) is made of CFRP, GFRP, BFRP or AFRP material.

4. According to claim 2, the shallow-water floating platform pure FRP cable mooring segmented weight adaptive self-sensing anchoring system is characterized in that: The joint (14) of the FRP cable (4) uses end packaging technology to prevent the colloid in the end joint from peeling off, reduce stress concentration in the connection area, and ensure connection strength and durability; the equal-rigidity filling material (13) is epoxy resin or polyurethane.

5. The shallow-water floating platform pure FRP cable mooring segmented weight adaptive self-sensing anchoring system according to any one of claims 2-4, characterized in that: The anchor foundation (3) is a steel suction bucket or an FRP reinforced concrete pile.

6. The shallow-water floating platform pure FRP cable mooring segmented weight adaptive self-sensing anchoring system according to claim 5 is characterized in that: The counterweight block (7) has the following counterweight requirements: counterweight blocks of different masses are suspended at different water depths, with lighter counterweight blocks arranged on the upper layer and heavier counterweight blocks arranged on the lower layer; the counterweight block (7) is made of corrosion-resistant material, such as concrete or steel, and has a spherical, cylindrical or square structure.

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