A system and method for monitoring cracks in a concrete floating foundation structure for offshore wind power

Abstract

The present application relates to the field of concrete structure crack monitoring, and discloses a kind of offshore wind power concrete floating foundation structure crack monitoring system and corresponding monitoring method suitable for marine environment and well adapted with anticorrosive coating.The monitoring system includes main control machine and photoelectric signal transceiver array and optical fiber network adhered to concrete floating foundation structure below anticorrosive coating;The photoelectric signal transceiver array includes photoelectric signal transceiver arranged according to certain position combination on the surface of concrete floating foundation structure;The optical fiber network is connected with photoelectric signal transceiver, and each photoelectric signal transceiver is communicated with the main control machine.

Description

Technical Field

[0001] This invention relates to the field of concrete structure crack monitoring, specifically to a crack monitoring system and method for offshore wind power concrete floating foundation structures. Background Technology

[0002] Concrete structures in marine environments are susceptible to corrosion from chloride, magnesium, and sulfate ions in seawater. These harmful ions penetrate the concrete through its pores and react with calcium hydroxide and hydrated calcium aluminate to form new salts. These insoluble salts often exhibit significant volume expansion, generating substantial internal stress within the concrete pores. Over time, this stress accumulates and causes cracks to appear in the concrete. Furthermore, chloride ions from seawater can also seep into the concrete through these cracks, causing corrosion on the steel reinforcement and severely impacting the structure's durability, ultimately jeopardizing the safety of the entire building. Therefore, crack monitoring of offshore wind turbine concrete floating foundations is crucial.

[0003] However, existing damage monitoring solutions for concrete structures are not applicable to marine environments. For example, the "Structural Damage Monitoring System and Method Based on Piezoelectric Ultrasonic-Sensitive Grid" proposed by Zhang Benniu et al. uses metal wires as sensitive wires, which are prone to corrosion in marine environments, causing the monitoring system to fail. Furthermore, the monitoring system contains complex control circuits. The complex control circuits, when routed on the surface of the floating foundation structure, can interfere with the adhesion of the anti-corrosion coating to the concrete surface, causing the anti-corrosion coating to easily fall off and thus accelerating the corrosion of the foundation structure. Summary of the Invention

[0004] The technical problem to be solved by this invention is to propose a crack monitoring system and corresponding monitoring method for offshore wind power concrete floating foundation structures that is suitable for marine environments and can be well adapted to anti-corrosion coatings.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] A crack monitoring system for offshore wind power concrete floating foundation structures includes a main control unit, an array of photoelectric transceivers and an optical fiber network located beneath an anti-corrosion coating and adhered to the concrete floating foundation structure; the photoelectric transceiver array includes photoelectric transceivers arranged in a certain position on the surface of the concrete floating foundation structure; the optical fiber network connects the photoelectric transceivers, and each of the photoelectric transceivers communicates with the main control unit.

[0007] Furthermore, the photoelectric transceiver includes an optical signal transmitting unit, an optical signal receiving unit, an optical signal conversion unit, and a radio signal transmitting unit; the optical signal transmitting unit and the optical signal receiving unit are both connected to the optical signal conversion unit, and the optical signal conversion unit is connected to the radio signal transmitting unit; the photoelectric transceiver communicates with the main control unit through the radio signal transmitting unit.

[0008] Furthermore, the arrangement of the photoelectric transceivers on the surface of the concrete floating foundation structure includes:

[0009] A positioning grid is established on the surface of the concrete floating foundation structure. Every four photoelectric transceivers are positioned on one positioning grid, that is, a photoelectric transceiver is set at each corner of each positioning grid.

[0010] Furthermore, each positioning grid is equipped with an optical fiber network, which consists of longitudinal and transverse optical fibers. The intersection of the longitudinal and transverse optical fibers is an optical fiber network node. At the optical fiber network node, the optical signals in the two optical fibers can intersect and be transmitted to each other, and each optical fiber network node has its own unique number.

[0011] On the other hand, based on the above-mentioned monitoring system, the present invention also provides a method for monitoring cracks in offshore wind power concrete floating foundation structures, comprising the following steps:

[0012] S1. The optical signals in each fiber optic network node are collected by the photoelectric transceiver and sent to the main control computer via radio signal to establish a complete coordinate system for monitoring the surface of the concrete structure.

[0013] S2. By monitoring in real time whether there is an optical signal in each fiber optic network node, it can be determined whether a break has occurred in the fiber optic network. If so, proceed to step S3; otherwise, return to this step.

[0014] S3. Based on the fiber optic network nodes that are missing optical signals, determine the relevant information of cracks on the surface of the concrete structure and send it to the main control computer in real time.

[0015] S4. The main control unit continuously monitors whether there are optical fiber network nodes near the crack that are continuously losing optical signals, in order to determine whether the crack is continuously expanding or increasing. If the number of optical fiber network nodes losing optical signals exceeds the set threshold, an alarm will be issued.

[0016] Furthermore, in step S3, the relevant information about the cracks on the surface of the concrete structure includes: the location, length, width, approximate shape, and time of occurrence of the cracks.

[0017] Furthermore, the location, length, width, and approximate shape of the cracks on the concrete surface are determined by monitoring the number and distribution of optical fiber network nodes that are missing optical signals; the time when the cracks on the concrete surface appear is determined by monitoring the time when the optical fiber network nodes are missing optical signals.

[0018] The beneficial effects of this invention are:

[0019] The monitoring system in this invention combines a photoelectric signal transceiver array and an optical fiber network, which is tightly adhered to the concrete floating foundation structure and located below the anti-corrosion layer, thereby reducing the possibility of corrosion.

[0020] Furthermore, since the optical fibers currently in use are mostly quartz-based optical fibers, whose main component is high-purity quartz glass, they have good corrosion resistance; while the housing of the optoelectronic signal transceiver is made of polyethylene, which has very stable chemical properties and excellent resistance to seawater erosion, and will not undergo electrochemical corrosion.

[0021] Therefore, the monitoring system in this invention is more suitable for concrete structures in marine environments.

[0022] In addition, there are no additional control lines besides the fiber optic network, making the system simple, efficient, and compatible with anti-corrosion coatings. Based on this monitoring system, when cracks appear on the surface of the concrete foundation structure, they will tear the complete fiber optic network, causing the fibers to break and resulting in missing optical signals at the fiber optic network nodes. Therefore, by monitoring the signals of each fiber optic network node with a unique number in real time, and combining this with the established monitoring coordinate system of the concrete structure surface, the number and distribution of fiber optic network nodes with missing optical signals can be determined, thereby obtaining relevant information about cracks on the concrete structure surface.

[0023] Therefore, this invention can effectively monitor the damage to offshore wind power concrete floating foundation structures, issue timely warnings when the damage exceeds a set threshold, and provide guidance for the maintenance of concrete foundations. Attached Figure Description

[0024] Figure 1 A schematic diagram of fiber optic network layout and crack monitoring;

[0025] Figure 2 This is a schematic diagram showing the arrangement of photoelectric signal transceivers on a concrete floating foundation structure.

[0026] Figure 3 A flowchart for monitoring cracks in offshore wind power concrete floating foundation structures.

[0027] The markings in the diagram are as follows: 1- Photoelectric transceiver, 2- Fiber optic network node, 3- Fiber optic network, 4- Broken fiber optic cable, 5- Fiber optic network node with missing optical signal due to fiber breakage, 6- Cracks on the surface of the concrete foundation structure, 7- Concrete foundation structure, 8- Positioning grid. Detailed Implementation

[0028] This invention aims to propose a crack monitoring system and corresponding monitoring method for offshore wind power concrete floating foundation structures, suitable for marine environments and well-adapted to anti-corrosion coatings. The monitoring system includes a main control unit, an array of photoelectric transceivers tightly adhered to the concrete floating foundation structure beneath the anti-corrosion coating, and an optical fiber network. The photoelectric transceiver array consists of photoelectric transceivers arranged in a specific configuration on the surface of the concrete floating foundation structure. The photoelectric transceivers are connected to the optical fiber network, where optical signals from two optical fibers at fiber network nodes can intersect and transmit. Each fiber network node has its own unique number. By monitoring the presence of optical signals generated by the photoelectric transceivers at the fiber network nodes, the system determines whether there are broken optical fibers and fiber network nodes where optical signals are missing due to fiber breakage. The photoelectric transceivers transmit information about fiber network nodes where optical signals are missing due to fiber breakage to the main control unit via radio. The main control unit analyzes the occurrence time, number, and distribution of the missing optical signals from these fiber network nodes to obtain information such as the location, length, width, approximate shape, and occurrence time of cracks on the surface of the concrete foundation structure.

[0029] Example:

[0030] In practical implementation, an array of photoelectric transceivers is installed on the surface of the concrete foundation structure 7, establishing a positioning grid 8 that covers the surface of the foundation structure 7. The photoelectric transceiver array consists of photoelectric transceivers 1 arranged in a specific combination, with four photoelectric transceivers positioning one grid 8; that is, one photoelectric transceiver is placed at the corner of each positioning grid 8. Figure 2 As shown.

[0031] The photoelectric transceiver 1 includes an optical signal transmitting unit, an optical signal receiving unit, an optical signal conversion unit, and a radio signal transmitting unit; the optical signal transmitting unit and the optical signal receiving unit are both connected to the optical signal conversion unit, and the optical signal conversion unit is connected to the radio signal transmitting unit; the photoelectric transceiver communicates with the main control unit through the radio signal transmitting unit.

[0032] An optical fiber network 3 is installed between each positioning grid, and the photoelectric transceiver 1 is connected to the optical fiber network 3. The optical fiber network 3 is composed of longitudinal and transverse optical fibers, and the intersection of the transverse and longitudinal optical fibers is the optical fiber network node 2. The optical signals in the two optical fibers at the optical fiber network node 2 can intersect and be transmitted to each other, and each optical fiber network node 2 has its own unique number.

[0033] When cracks (6) appear on the surface of the concrete foundation structure, the optical fibers break due to the tearing of the intact optical fiber network (3). This results in broken optical fibers (4) and optical fiber network nodes (5) where optical signals are lost due to fiber breakage. Figure 1 As shown. Therefore, by monitoring whether there is an optical signal generated by the photoelectric transceiver 1 at the optical fiber network node 2, it is possible to determine whether there is a broken optical fiber 4 and an optical fiber network node 5 where the optical signal is lost due to the optical fiber breakage, thus determining the damage condition of the concrete foundation structure surface.

[0034] Based on the above monitoring system, the monitoring method provided by the present invention is as follows: Figure 3 As shown, it includes the following steps:

[0035] S1. The optical signals in each fiber optic network node are collected by the photoelectric transceiver and sent to the main control computer via radio signal to establish a complete coordinate system for monitoring the surface of the concrete structure.

[0036] S2. By monitoring in real time whether there is an optical signal in each fiber optic network node, it can be determined whether a break has occurred in the fiber optic network. If so, proceed to step S3; otherwise, return to this step to continue monitoring.

[0037] In this step, the principle of the photoelectric transceiver monitoring the fiber optic network nodes is as follows: Assume that the four photoelectric transceivers on a certain grid are numbered a1, b1, c1, and d1 respectively; then these four photoelectric transceivers can uniquely locate the grid. The photoelectric transceiver numbered a1 is responsible for sending optical signals through the fiber optic network in this grid, and the photoelectric transceiver numbered b1 is responsible for receiving optical signals; the nodes in the fiber optic network can be numbered according to the row and column positions, such as the node number in the first row and first column being 00010001, the node number in the first row and second column being 00010002, the node number in the second row and first column being 00020001, the node number in the second row and second column being 00020002, and so on. If at a certain moment, the photoelectric transceiver numbered b1 does not receive a signal from the fiber optic node numbered 00010002, it means that the optical signal of that node is missing.

[0038] S3. Based on the fiber optic network nodes that lack optical signals, determine the relevant information of cracks on the surface of the concrete structure and send it to the main control unit in real time; the relevant information of cracks on the surface of the concrete structure mentioned here includes: the location, length, width, approximate shape, and time of occurrence of the cracks on the concrete surface.

[0039] Among them, the location, length, width, approximate shape of cracks on the concrete surface, as well as the number and distribution of fiber optic network nodes that are missing optical signals, are determined.

[0040] The occurrence time of the concrete surface crack damage was determined by monitoring the time of missing optical signals at the fiber optic network nodes.

[0041] S4. The main control unit continuously monitors whether there are optical fiber network nodes near the crack that are continuously losing optical signals, in order to determine whether the crack is continuously expanding or increasing. If the number of optical fiber network nodes losing optical signals exceeds the set threshold, an alarm will be issued.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Obviously, various modifications and variations made by those skilled in the art without departing from the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A crack monitoring system for offshore wind power concrete floating foundation structures, characterized in that, The system includes a main control unit, an array of photoelectric transceivers and an optical fiber network located beneath an anti-corrosion coating and adhered to a concrete floating foundation structure; the photoelectric transceiver array includes photoelectric transceivers arranged in a certain position on the surface of the concrete floating foundation structure; the optical fiber network connects the photoelectric transceivers, and each photoelectric transceiver communicates with the main control unit. The arrangement of the photoelectric transceivers on the surface of the concrete floating foundation structure includes: A positioning grid is established on the surface of the concrete floating foundation structure. Every four photoelectric transceivers are positioned on one positioning grid, that is, a photoelectric transceiver is set at each corner of each positioning grid. Each positioning grid is equipped with an optical fiber network, which consists of longitudinal and transverse optical fibers. The intersection of the longitudinal and transverse optical fibers is an optical fiber network node. At the optical fiber network node, the optical signals in the two optical fibers can intersect and be transmitted to each other, and each optical fiber network node has its own unique number. The photoelectric transceiver will transmit information about fiber optic network nodes that are unable to receive optical signals due to fiber breakage to the main control unit via radio. The main control unit will analyze the occurrence time, number, and distribution of the fiber optic network nodes with missing optical signals to obtain information on the location, length, width, approximate shape, and occurrence time of cracks on the surface of the concrete foundation structure.

2. The offshore wind power concrete floating foundation structure crack monitoring system as described in claim 1, characterized in that, The photoelectric transceiver includes an optical signal transmitting unit, an optical signal receiving unit, an optical signal conversion unit, and a radio signal transmitting unit; the optical signal transmitting unit and the optical signal receiving unit are both connected to the optical signal conversion unit, and the optical signal conversion unit is connected to the radio signal transmitting unit; the photoelectric transceiver communicates with the main control unit through the radio signal transmitting unit.

3. The offshore wind power concrete floating foundation structure crack monitoring system as described in claim 1, characterized in that, The housing of the photoelectric transceiver is made of polyethylene.

4. A method for monitoring cracks in offshore wind power concrete floating foundation structures, applied to the monitoring system described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Acquire optical signals from each fiber optic network node using an optoelectronic transceiver and transmit them to the main control unit via radio signals to establish a complete coordinate system for monitoring the surface of the concrete structure. S2. By monitoring in real time whether there is an optical signal in each fiber optic network node, it can be determined whether a break has occurred in the fiber optic network. If so, proceed to step S3; otherwise, return to this step. S3. Based on the fiber optic network nodes that are missing optical signals, determine the relevant information of cracks on the surface of the concrete structure and send it to the main control computer in real time. S4. The main control unit continuously monitors whether there are optical fiber network nodes near the crack that are continuously losing optical signals, in order to determine whether the crack is continuously expanding or increasing. If the number of optical fiber network nodes losing optical signals exceeds the set threshold, an alarm will be issued.

5. The method for monitoring cracks in offshore wind power concrete floating foundation structures as described in claim 4, characterized in that, In step S3, the relevant information of the cracks on the surface of the concrete structure includes: the location, length, width, approximate shape, and time of occurrence of the cracks.

6. The method for monitoring cracks in offshore wind power concrete floating foundation structures as described in claim 5, characterized in that, The location, length, width, and approximate shape of the cracks on the surface of the concrete structure are determined by monitoring the number and distribution of optical fiber network nodes that are missing optical signals; the time when the cracks on the surface of the concrete structure appear is determined by monitoring the time when the optical fiber network nodes are missing optical signals.

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