Main cable tightening quality evaluation method and system based on distributed optical fiber temperature measurement

Abstract

The invention relates to the technical field of cable production, in particular to a main cable tightening quality evaluation method and system based on distributed optical fiber temperature measurement. Comprising the steps that the section of a main cable is layered based on the diameter of the main cable, a plurality of cable strands with temperature measuring optical fibers are arranged on each layer in the circumferential direction, and the cable strands are arranged in the length direction of the main cable in a full-length mode; after the main cable is tightened, acquiring temperature data in the main cable through a temperature measuring optical fiber, and synchronously acquiring illumination radiation intensity data on the outer side of the main cable; screening the temperature data based on the illumination radiation intensity data, and obtaining a correlation coefficient between two adjacent layers on each section of the main cable based on the screened temperature data; and comparing the correlation coefficient with a set threshold value, evaluating the cable tightening quality of the section of the main cable according to a comparison result, and formulating corresponding treatment measures. The method for evaluating the cable tightening quality of the main cable is simple, the cable tightening quality of all sections of the main cable can be accurately evaluated, the evaluation range is large, and the precision is extremely high.

Description

Technical Field

[0001] This invention relates to the field of cable production technology, specifically to a method and system for evaluating the quality of main cable tensioning based on distributed optical fiber temperature measurement. Background Technology

[0002] The main cable of the suspension bridge is composed of several PPWS strands. After the main cable strands are erected, the cross-section of the main cable is hexagonal, which differs from the designed circular cross-section. At this point, cable tightening operations are required to compress the main cable from the hexagonal cross-section into a circular cross-section to facilitate subsequent cable clamp installation and positioning operations.

[0003] Currently, cable tensioning is generally performed by cable tensioning machines, with tightening every 1 meter, and the interval between clamps increasing to 0.5 meters. Additional steel strips are added near the clamps at both ends to maintain the main cable's porosity at those clamp locations. As suspension bridge spans continue to increase, the diameter of the main cable is also growing. The main cable diameter of the under-construction Shiziyang Bridge is approximately 1.5 meters. It remains unclear whether traditional tensioning methods can meet the requirements of ultra-large diameter main cables. After tensioning, the current general requirements are a porosity control standard of 18±2% inside the clamps and 20±2% outside the clamps, with the main cable's out-of-roundness not exceeding 2% of the main cable's design diameter. Due to limitations in workload and efficiency, tensioning operations cannot cover all sections of the main cable. This may result in some sections of large-diameter main cables, after using existing tensioning methods, not meeting the relevant design and specification requirements for porosity and diameter.

[0004] To address this technical challenge, an existing technology, titled "Main Cable Pre-tensioning Method and System Based on Real-Time Temperature Across the Entire Main Cable Domain," proposes a temperature-based method for main cable pre-tensioning. Specifically, during main cable manufacturing, several main cable strands are selected and fitted with temperature-sensitive optical fibers. These fibers are arranged along the entire length of the main cable strands, with multiple temperature grating measurement points evenly spaced along their length. During main cable assembly, the main cable strands are installed in their designated positions, ensuring the temperature-sensitive fibers are radially spaced across the main cable cross-section. Before pre-tensioning, temperature sensors are placed on the outer side of the main cable. The internal temperature of the main cable is collected using the temperature-sensitive optical fibers, and the surface temperature is collected using the temperature sensors. When the temperature difference between the internal and surface temperatures of the main cable falls within a set range, the main cable is pre-tensioned. This process is repeated until pre-tensioning is completed at all locations on the main cable. This method utilizes optical fiber to collect the internal temperature of the main cable before pre-tensioning. It also uses an external temperature sensor to compare the external and internal temperatures in real time, which can minimize the problem of cable tensioning errors when the temperature difference is large. This can improve the quality of cable tensioning operations, reduce the probability of main cable wire twisting, cross-linking, and bulging, and improve the control level of the main cable.

[0005] However, this method also has some problems. Because it compares the internal and external temperatures of the main cable, the comparison method is relatively crude. Of course, tightening the cable based on this comparison method can improve the quality of the tightening, but it cannot accurately assess the tightening situation, nor can it accurately judge the overall tightening quality of the main cable, and ensure that the construction state of the main cable structure is as consistent as possible with the design state. Summary of the Invention

[0006] The purpose of this application is to address the shortcomings of the aforementioned background technology and provide a method and system for evaluating the quality of main cable tensioning based on distributed optical fiber temperature measurement.

[0007] The technical solution of this application is: a method for evaluating the quality of main cable tensioning based on distributed optical fiber temperature measurement, comprising, The main cable cross-section is divided into layers based on the main cable diameter. Multiple strands with temperature-measuring optical fibers are arranged circumferentially in each layer, and the strands are arranged along the length of the main cable. After the main cable is tightened, temperature data inside the main cable is collected through a temperature-measuring optical fiber, and the light radiation intensity data on the outside of the main cable is collected simultaneously. Temperature data is filtered based on light radiation intensity data, and the correlation coefficient between two adjacent layers on each section of the main cable is obtained based on the filtered temperature data. The correlation coefficient is compared with the set threshold, and the cable tensioning quality of the main cable at this section is evaluated based on the comparison results, and corresponding handling measures are formulated.

[0008] According to the method for evaluating the quality of main cable tensioning based on distributed optical fiber temperature measurement provided in this application, the method for layering the main cable cross-section based on the main cable diameter includes: setting the cross-sectional area of ​​the main cable from 2 / 3R to R as the surface layer, setting the cross-sectional area of ​​the main cable from 1 / 3R to 2 / 3R as the middle layer, and setting the cross-sectional area of ​​the main cable from 0 to 1 / 3R as the core layer; wherein R is the radius of the main cable.

[0009] According to the method for evaluating the tensioning quality of a main cable based on distributed optical fiber temperature measurement provided in this application, the method of arranging multiple strands with temperature-measuring optical fibers in each layer along the circumferential direction includes: arranging multiple sets of strands with temperature-measuring optical fibers in the surface layer, middle layer and core layer respectively, and the multiple sets of strands with temperature-measuring optical fibers arranged in each layer are evenly spaced along the circumferential direction.

[0010] According to the main cable tensioning quality assessment method based on distributed optical fiber temperature measurement provided in this application, the cable strands with temperature-measuring optical fibers in the surface layer, middle layer and core layer are arranged at uniform intervals in the radial direction.

[0011] According to the method for evaluating the cable tensioning quality of the main cable based on distributed optical fiber temperature measurement provided in this application, the method for filtering temperature data based on light radiation intensity data includes: filtering temperature data within a time period in which the light radiation intensity is not less than a set intensity as the filtered temperature data.

[0012] According to the main cable tensioning quality assessment method based on distributed optical fiber temperature measurement provided in this application, the method for obtaining the correlation coefficient between two adjacent layers on each cross-section of the main cable based on screened temperature data includes: normalizing the screened temperature data according to the following formula. in: —The i-th layer of the main cable at time t k Temperature monitoring value; —Bridge site at time t k Temperature monitoring value; —Temperature value after normalization; The correlation coefficient between two adjacent layers on each cross section of the main cable is calculated using the following formula. in: —Correlation coefficient between layer i and layer j at section x of the main cable, where i and j are two adjacent layers, and x is the coordinate position along the length of the main cable, in meters; N — Count of data points within the temperature data window; —Temperature value after normalization; μ i —Filter the average temperature of the i-th layer within the temperature data window; μ j — Filter the average temperature of the j-th layer within the temperature data window.

[0013] According to the method for evaluating the tensioning quality of a main cable based on distributed optical fiber temperature measurement provided in this application, the method for evaluating the tensioning quality of a section of the main cable based on the comparison results includes: if the correlation coefficient is not less than a first set threshold, the tensioning quality of the main cable section corresponding to the correlation coefficient is excellent; if the correlation coefficient is less than the first set threshold and not less than a second set threshold, the tensioning quality of the main cable section corresponding to the correlation coefficient is qualified; if the correlation coefficient is less than the second set threshold, the tensioning quality of the main cable section corresponding to the correlation coefficient is questionable; the first set threshold is greater than the second set threshold.

[0014] According to the main cable tensioning quality assessment method based on distributed optical fiber temperature measurement provided in this application, the method for formulating corresponding handling measures includes: when the main cable cross-section tensioning quality is excellent, formulating handling measures that do not require re-inspection; when the main cable cross-section tensioning quality is qualified, formulating handling measures that record the location and conduct random inspections of the main cable cross-section at the recorded location at a set percentage; when the main cable cross-section tensioning quality is questionable, formulating handling measures that involve manual random inspection and measurement of the cable diameter and porosity at the questionable cross-section.

[0015] According to the method for evaluating the cable tensioning quality of the main cable based on distributed optical fiber temperature measurement provided in this application, the set light intensity is 500W / m².

[0016] This application also relates to a main cable tensioning quality assessment system based on distributed optical fiber temperature measurement. The assessment system operates according to the aforementioned method for assessing main cable tensioning quality based on distributed optical fiber temperature measurement, including... The temperature measuring module includes multiple strands with temperature measuring optical fibers. The main cable is divided into multiple layers in the radial direction. Each layer is equipped with multiple strands with temperature measuring optical fibers arranged at intervals along the circumference. The strands with temperature measuring optical fibers are arranged along the length of the main cable. A light intensity acquisition module, which is used to acquire light radiation intensity data on the outside of the main cable; A filtering module that filters the temperature data acquired by the temperature measurement module based on light radiation intensity data; The calculation module obtains the correlation coefficient between two adjacent layers on each section of the main cable based on the filtered temperature data; The comparison module is used to compare the correlation coefficient with a set threshold, evaluate the cable tensioning quality of the main cable section based on the comparison results, and formulate corresponding handling measures.

[0017] The advantages of this application are: 1. The temperature-measuring optical fiber of this application is arranged along the length of the main cable, so the traditional cable tensioning interval control can be improved to 100% of the cross-section of the entire main cable, with a wide coverage. The evaluation method incorporates solar radiation intensity and filters the collected temperature data, which improves the evaluation accuracy. It can accurately obtain the cable tensioning quality of the main cable. The operation is simple and convenient. Moreover, the cable strands with temperature-measuring optical fibers can be extended from the construction period to the operation period and reused as part of the suspension bridge health monitoring system, forming a smart cable structure. 2. This application divides the main cable into layers in the radial direction. By arranging multiple sets of optical fibers in each layer, the temperature of multiple parts of each section of the main cable can be measured evenly. The temperature of multiple locations on each section can be accurately obtained, and the cable tensioning quality of that section can be accurately evaluated. 3. This application arranges multiple sets of evenly distributed cable strands with temperature-measuring optical fibers in each layer, which can uniformly obtain the temperature of each section and each layer. It can accurately obtain the main cable tension quality with a small number of cable strands, which not only ensures the accuracy of the assessment, but also reduces the overall cost of the cable. 4. In this application, the strands of the cable with temperature-measuring optical fibers in the surface, middle and core layers are arranged at uniform intervals in the radial direction. This ensures the consistency of data comparison and analysis between adjacent layers, making the evaluation quality more reliable and the cable tightness quality evaluation more accurate. 5. This application filters temperature data by using light radiation intensity, selecting temperature data within a time period when the light radiation intensity is not less than a set intensity. This part of the temperature data has less interference and can better reflect the true internal temperature of the main cable, greatly improving the accuracy of the cable tensioning quality assessment. 6. The method of obtaining the correlation coefficient in this application is very simple. By normalizing the screened temperature data, baseline drift can be eliminated, so that the obtained correlation coefficient can accurately reflect the difference in the relationship between two adjacent layers and improve the accuracy of the cable tensioning quality assessment. 7. The method of evaluating the cable tensioning quality in this application is to compare the correlation coefficient with a first set threshold and a second set threshold. By calibrating the first set threshold and the second set threshold, the cable tensioning status of the current section can be accurately determined. The entire comparison method is simple and the evaluation is rapid. 8. This application formulates corresponding measures based on the cable tensioning quality assessment results, which can facilitate construction personnel to quickly obtain the corresponding countermeasures and further improve the cable tensioning quality of the main cable; 9. This application defines a set intensity, which facilitates rapid filtering of temperature data. The method for filtering temperature data is simple and efficient. 10. This application also relates to an evaluation system that integrates the above-mentioned evaluation methods and can be integrated into the control system to automatically evaluate the quality of cable tensioning, thereby greatly improving the evaluation efficiency.

[0018] The main cable tensioning quality assessment method of this application is simple and can accurately assess the tensioning quality of all sections of the main cable. It has a very large assessment range and extremely high accuracy, and has great potential for widespread application. Attached Figure Description

[0019] Figure 1 : A schematic diagram of the cable strand arrangement with temperature-measuring optical fiber in this application. Detailed Implementation

[0020] The embodiments of this application are described in detail below, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0021] In the description of this application, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0023] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0024] This application relates to a method for assessing the tensioning quality of main cables based on distributed optical fiber temperature measurement. This method collects the internal temperature of the main cable using temperature-measuring optical fibers and assesses the tensioning quality based on the collected temperature data. Compared to traditional assessment methods, this method can assess the tensioning quality of all sections of the main cable with extremely high accuracy. Furthermore, it allows for the development of corresponding remedial measures based on the assessment results, facilitating operation by construction personnel. Even after the assessment is completed, the temperature-measuring optical fibers remaining inside the main cable can still collect data during actual application, reusing them as part of the suspension bridge health monitoring system to form a smart cable structure.

[0025] Specifically, the main cable tensioning quality assessment method based on distributed optical fiber temperature measurement proposed in this application can be carried out according to the following steps: S1. The main cable cross-section is divided into layers based on the main cable diameter. Multiple strands with temperature measuring optical fibers are arranged circumferentially in each layer. The strands are arranged along the length of the main cable. As can be seen, the temperature-sensing optical fiber of this application is arranged at equal lengths along the length of the main cable. Therefore, the temperature-sensing optical fiber of this application can collect temperature information of all sections of the main cable. At the same time, the multiple strands of the main cable with temperature-sensing optical fiber are distributed at intervals in the circumferential direction of the section, so that temperature information at different positions on the section can be collected. This application divides the main cable into layers along the radial direction. The subsequent evaluation of the cable tensioning quality is obtained by comparing two adjacent layers. The main cable is divided into at least two radial layers. The more layers there are, the more data is collected, the larger the data processing volume is, and the higher the evaluation accuracy of the cable tensioning quality. However, more temperature-sensing optical fibers are required. Therefore, it is necessary to set the parameters according to the actual situation of the main cable. S2. After the main cable is tightened, temperature data inside the main cable is collected through a temperature-measuring optical fiber, and the light radiation intensity data outside the main cable is collected simultaneously. This application uses synchronous collection of light radiation intensity to filter temperature data. When the light radiation intensity is low, the temperature difference inside the main cable is significantly different from that when the light radiation intensity is high. In other words, the temperature difference inside the main cable is relatively poor when the light radiation intensity is low, making it difficult to accurately obtain the relative relationship between two radially adjacent layers. Therefore, this application collects the light radiation intensity on the outside of the main cable and filters out the temperature data corresponding to the higher light radiation intensity. Based on this temperature data, subsequent analysis can be performed, which can eliminate the error caused by light and improve the accuracy of the evaluation. S3. Filter the temperature data based on the light radiation intensity data, and obtain the correlation coefficient between two adjacent layers on each section of the main cable based on the filtered temperature data; This application actually evaluates the cable tensioning quality by comparing the temperature of two adjacent layers on the main cable cross section. The correlation coefficient obtained based on the screened temperature data actually reflects the temperature of two adjacent layers on the main cable cross section. S4. Compare the correlation coefficient with the set threshold, evaluate the cable tensioning quality of the main cable at this section based on the comparison results, and formulate corresponding handling measures. The threshold is set through a large number of calibration tests, namely, constructing standard tests, recording the correlation coefficient of the main cable section and the cable tension during the standard tests, and obtaining the set threshold through calibration data; in subsequent practical applications, the correlation coefficient obtained by collection and calculation is compared with the set threshold to obtain the corresponding cable tension, and corresponding handling measures are formulated based on the cable tension.

[0026] In some embodiments of this application, step S1 described above has been optimized, specifically, as follows: Figure 1 As shown, the method for layering the main cable cross-section based on the main cable diameter is as follows: the cross-sectional area from 2 / 3R to R is designated as the surface layer, the cross-sectional area from 1 / 3R to 2 / 3R is designated as the middle layer, and the cross-sectional area from 0 to 1 / 3R is designated as the core layer; where R is the radius of the main cable. That is, the main cable is evenly divided into three layers according to the radius, with the surface and middle layers having a ring structure and the core layer having a columnar structure. In practical applications, it is not limited to three layers; it can be divided into multiple layers, but at least two layers are required.

[0027] In this embodiment, the method of arranging multiple strands of cable with temperature-sensing optical fibers along the circumferential direction in each layer is as follows: multiple sets of cable strands with temperature-sensing optical fibers are arranged in the surface layer, middle layer, and core layer, and the multiple sets of cable strands with temperature-sensing optical fibers arranged in each layer are evenly spaced along the circumferential direction. Figure 1 As shown, in this embodiment, three sets of strands with temperature-sensing optical fibers are arranged in the surface layer, middle layer, and core layer respectively (the three sets of strands with temperature-sensing optical fibers in the surface layer are A1, A2, and A3; the three sets of strands with temperature-sensing optical fibers in the middle layer are B1, B2, and B3; and the three sets of strands with temperature-sensing optical fibers in the core layer are C1, C2, and C3). The three sets of strands with temperature-sensing optical fibers are evenly distributed in each layer along the circumference. In fact, each set of strands with temperature-sensing optical fibers is located in the middle position of the radial direction of each layer.

[0028] Furthermore, in this embodiment, the strands of temperature-sensing optical fibers within the surface, middle, and core layers are arranged at uniform intervals in the radial direction. That is, according to... Figure 1 As shown, in this embodiment, the surface layer, middle layer, and core layer each have three sets of strands with temperature-sensing optical fibers. The three sets of strands in each layer are evenly distributed circumferentially, while the strands in adjacent layers are spaced apart radially. It is assumed that the three sets of strands in the surface layer are at 0° (e.g.,...). Figure 1 As shown in A1), 120° (e.g.) Figure 1 As shown in A2), and 240° (as ... Figure 1 As shown in A3), the three sets of cable strands with temperature-measuring optical fibers in the middle and core layers are also at 0° (as shown in A3). Figure 1 As shown in B1 and C1), 120° (as ... Figure 1 (as shown in B2 and C2) and 240° (as shown in B2 and C2) and 240 Figure 1 (As shown in B3 and C3). This arrangement allows for the uniform acquisition of temperature data at each location on the main cable cross-section. Furthermore, it provides better consistency when comparing the temperature differences between adjacent layers, reducing interference and improving assessment accuracy.

[0029] In other embodiments of this application, step S3 described above is optimized. Specifically, the method for filtering temperature data based on light radiation intensity data is as follows: temperature data within a time period where the light radiation intensity is not less than a set intensity is selected as the filtered temperature data. In this embodiment, the set light radiation intensity is 500W / m². That is, in practical applications, this embodiment continuously collects temperature data inside the main cable through a temperature-measuring optical fiber, and simultaneously collects the light radiation intensity outside the main cable. Finally, the data is summarized and analyzed, and the time period when the light radiation intensity is not less than 500W / m² is recorded. Then, temperature data within the same time period is selected from the collected temperature data. This part of the temperature data is the filtered data, and subsequent analyses are based on these data.

[0030] The selected temperature data are those with a light radiation intensity no less than the set intensity. This data eliminates interference from light, which greatly improves the accuracy of subsequent cable tightening quality assessment.

[0031] In a further embodiment of this application, the above-described S3 is optimized. Specifically, the method for obtaining the correlation coefficient between two adjacent layers on each cross-section of the main cable based on the screened temperature data is as follows: the screened temperature data is normalized according to the following formula. in: —The i-th layer of the main cable at time t k Temperature monitoring values, in °C; —Bridge site at time t k Temperature monitoring values, in °C; —Normalized temperature value, in °C; The correlation coefficient between two adjacent layers on each cross section of the main cable is calculated using the following formula. in: —Correlation coefficient between layer i and layer j at section x of the main cable, where i and j are two adjacent layers, and x is the coordinate position along the length of the main cable, in meters; N — Count of data points within the temperature data window; —Normalized temperature value, in °C; μ i —Filter the average temperature of the i-th layer within the temperature data window. The unit is ℃; μ j —Filter the average temperature of the j-th layer within the temperature data window. The unit is ℃; t k —Time series points, unit: min.

[0032] In some other embodiments of this application, step S4 above has been optimized. Specifically, the method for evaluating the cable tensioning quality of the main cable section based on the comparison results is as follows: if the correlation coefficient is not less than a first set threshold, the cable tensioning quality of the main cable section corresponding to the correlation coefficient is excellent; if the correlation coefficient is less than the first set threshold and not less than a second set threshold, the cable tensioning quality of the main cable section corresponding to the correlation coefficient is qualified; if the correlation coefficient is less than the second set threshold, the cable tensioning quality of the main cable section corresponding to the correlation coefficient is questionable; the first set threshold is greater than the second set threshold.

[0033] The first set threshold in this embodiment is 0.95, and the second set threshold in this application is 0.85. In actual application, the values ​​are not limited to the above values, and can be set according to actual needs.

[0034] After obtaining the cable tensioning quality assessment results, corresponding measures can be formulated based on these results: when the cable tensioning quality of the main cable section is excellent, measures that do not require re-inspection can be formulated; when the cable tensioning quality of the main cable section is qualified, measures for random sampling inspection can be formulated, including recording the locations and setting a percentage (e.g., setting the percentage as 5%, assuming that the cable tensioning quality assessment results of 100 locations on the entire main cable are qualified, then randomly selecting 5 locations for re-inspection) can be formulated; when the cable tensioning quality of the main cable section is questionable, measures for manual sampling inspection and measurement of cable diameter and porosity at the questionable sections can be formulated.

[0035] In the actual assessment of the main cable tensioning quality during the main cable fabrication process, the section from 2 / 3R to R of the main cable is designated as the surface layer, the section from 1 / 3R to 2 / 3R is designated as the middle layer, and the section from 0 to 1 / 3R is designated as the core layer. Multiple sets of cable strands with temperature-sensing optical fibers are arranged in the surface, middle, and core layers. The multiple sets of cable strands with temperature-sensing optical fibers in each layer are evenly spaced circumferentially, while the cable strands with temperature-sensing optical fibers in the surface, middle, and core layers are evenly spaced radially. After the cable tightening operation is completed, temperature data inside the main cable is collected via a temperature-measuring optical fiber. The temperature monitoring time window is no less than three days, and the sampling frequency is no more than 1 minute / time, for example, sampling once per minute, and this is carried out continuously for three days. Each sampling point needs to collect 3 days × 24 hours × 60 minutes = 4320 temperature data points. Simultaneously, the solar radiation intensity data on the outside of the main cable is collected. Temperature data within a time period where the solar radiation intensity is not less than a set intensity are selected as the filtered temperature data. The filtered temperature data are then normalized according to the following formula. in: —The i-th layer of the main cable at time t k Temperature monitoring values, in °C; —Bridge site at time t k Temperature monitoring values, in °C; —Normalized temperature value, in °C; The correlation coefficient between two adjacent layers on each cross section of the main cable is calculated using the following formula. in: —Correlation coefficient between layer i and layer j at section x of the main cable, where i and j are two adjacent layers, and x is the coordinate position along the length of the main cable, in meters; N — Count of data points within the temperature data window; —Normalized temperature value, in °C; μ i —Filter the average temperature of the i-th layer within the temperature data window. The unit is ℃; μ j —Filter the average temperature of the j-th layer within the temperature data window. The unit is ℃; t k —Time series points, unit: min; After obtaining the correlation coefficients, perform the analysis according to the table below:

[0036] In addition, this application also relates to a main cable tensioning quality assessment system based on distributed optical fiber temperature measurement, including a temperature measurement module, a light intensity acquisition module, a screening module, a calculation module, and a comparison module. The temperature measurement module includes multiple strands with temperature-measuring optical fibers. The main cable is divided into multiple layers in the radial direction, and each layer is equipped with multiple strands with temperature-measuring optical fibers arranged at circumferential intervals. The strands with temperature-measuring optical fibers are arranged along the length of the main cable. The light intensity acquisition module is used to collect light radiation intensity data on the outside of the main cable. The screening module filters the temperature data obtained by the temperature measurement module based on the light radiation intensity data. The calculation module obtains the correlation coefficient between two adjacent layers on each cross section of the main cable based on the screened temperature data. The comparison module is used to compare the correlation coefficient with a set threshold, evaluate the tensioning quality of the main cable at that cross section based on the comparison results, and formulate corresponding handling measures.

[0037] This invention also provides a non-transitory computer-readable storage medium storing a computer program. The computer program includes program instructions that, when executed by a processor, implement the various steps of the method described in this invention, which will not be elaborated further here.

[0038] The computer-readable storage medium can be the data transmission apparatus or the internal storage unit of a computer device provided in any of the foregoing embodiments, such as the hard disk or memory of the computer device. The computer-readable storage medium can also be the external storage device of the computer device, such as the plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on the computer device.

[0039] Furthermore, the computer-readable storage medium may include both internal storage units and external storage devices of the computer device. The computer-readable storage medium is used to store the computer program and other programs and data required by the computer device. The computer-readable storage medium may also be used to temporarily store data that is to be output or has already been output.

[0040] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0041] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0042] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0043] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0044] This invention also provides a computer program product, including a computer program / instructions, which, when executed by a processor, implement the steps of the aforementioned method for assessing the quality of main cable tensioning based on distributed optical fiber temperature measurement. Content not described in detail in this specification constitutes prior art known to those skilled in the art.

[0045] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of this application as claimed. The scope of protection of this application is defined by the appended claims and their equivalents.

Claims

1. A method for assessing the tensioning quality of main cables based on distributed optical fiber temperature measurement, characterized in that: include, The main cable cross-section is divided into layers based on the main cable diameter. Multiple strands with temperature-measuring optical fibers are arranged circumferentially in each layer, and the strands are arranged along the length of the main cable. After the main cable is tightened, temperature data inside the main cable is collected through a temperature-measuring optical fiber, and the light radiation intensity data on the outside of the main cable is collected simultaneously. Temperature data is filtered based on light radiation intensity data, and the correlation coefficient between two adjacent layers on each section of the main cable is obtained based on the filtered temperature data. The correlation coefficient is compared with the set threshold, and the cable tensioning quality of the main cable at this section is evaluated based on the comparison results, and corresponding handling measures are formulated.

2. The main cable tensioning quality assessment method based on distributed optical fiber temperature measurement as described in claim 1, characterized in that: The method for layering the main cable cross-section based on the main cable diameter includes: setting the cross-sectional area of ​​the main cable from 2 / 3R to R as the surface layer, setting the cross-sectional area of ​​the main cable from 1 / 3R to 2 / 3R as the middle layer, and setting the cross-sectional area of ​​the main cable from 0 to 1 / 3R as the core layer; where R is the radius of the main cable.

3. The main cable tensioning quality assessment method based on distributed optical fiber temperature measurement as described in claim 2, characterized in that: The method of arranging multiple strands of cable with temperature-measuring optical fibers in each layer along the circumference includes: arranging multiple sets of cable strands with temperature-measuring optical fibers in the surface layer, middle layer and core layer respectively, with the multiple sets of cable strands with temperature-measuring optical fibers arranged in each layer being evenly spaced along the circumference.

4. The main cable tensioning quality assessment method based on distributed optical fiber temperature measurement as described in claim 3, characterized in that: The strands of temperature-measuring optical fibers in the surface, middle, and core layers are arranged at uniform intervals in the radial direction.

5. The main cable tensioning quality assessment method based on distributed optical fiber temperature measurement as described in claim 1, characterized in that: The method for filtering temperature data based on light radiation intensity data includes: filtering temperature data within a time period where the light radiation intensity is not less than a set intensity as the filtered temperature data.

6. The main cable tensioning quality assessment method based on distributed optical fiber temperature measurement as described in claim 1, characterized in that: The method for obtaining the correlation coefficient between two adjacent layers on each section of the main cable based on the screened temperature data includes: normalizing the screened temperature data according to the following formula. in: —The i-th layer of the main cable at time t k Temperature monitoring value; —Bridge site at time t k Temperature monitoring value; —Temperature value after normalization; The correlation coefficient between two adjacent layers on each cross section of the main cable is calculated using the following formula. in: —Correlation coefficient between layer i and layer j at section x of the main cable, where i and j are two adjacent layers, and x is the coordinate position along the length of the main cable, in meters; N — Count of data points within the temperature data window; —Temperature value after normalization; μ i —Filter the average temperature of the i-th layer within the temperature data window; μ j — Filter the average temperature of the j-th layer within the temperature data window.

7. The main cable tensioning quality assessment method based on distributed optical fiber temperature measurement as described in claim 1, characterized in that: The method for evaluating the cable tensioning quality of the main cable section based on the comparison results includes: if the correlation coefficient is not less than a first set threshold, the cable tensioning quality of the main cable section corresponding to the correlation coefficient is excellent; if the correlation coefficient is less than the first set threshold and not less than a second set threshold, the cable tensioning quality of the main cable section corresponding to the correlation coefficient is qualified; if the correlation coefficient is less than the second set threshold, the cable tensioning quality of the main cable section corresponding to the correlation coefficient is questionable; the first set threshold is greater than the second set threshold.

8. The main cable tensioning quality assessment method based on distributed optical fiber temperature measurement as described in claim 7, characterized in that: The methods for formulating corresponding handling measures include: when the main cable section tensioning quality is excellent, formulating handling measures that do not require re-inspection; when the main cable section tensioning quality is qualified, formulating handling measures that record the location and conduct random inspections of the main cable section at the recorded location at a set percentage; when the main cable section tensioning quality is questionable, formulating handling measures that involve manual random inspection and measurement of the cable diameter and porosity at the questionable section.

9. The main cable tensioning quality assessment method based on distributed optical fiber temperature measurement as described in claim 5, characterized in that: The set light intensity is 500W / m².

10. A main cable tensioning quality assessment system based on distributed optical fiber temperature measurement, characterized in that: The evaluation system operates according to the main cable tensioning quality evaluation method based on distributed optical fiber temperature measurement as described in any one of claims 1 to 9, including: The temperature measuring module includes multiple strands with temperature measuring optical fibers. The main cable is divided into multiple layers in the radial direction. Each layer is equipped with multiple strands with temperature measuring optical fibers arranged at intervals along the circumference. The strands with temperature measuring optical fibers are arranged along the length of the main cable. A light intensity acquisition module, which is used to acquire light radiation intensity data on the outside of the main cable; A filtering module that filters the temperature data acquired by the temperature measurement module based on light radiation intensity data; The calculation module obtains the correlation coefficient between two adjacent layers on each section of the main cable based on the filtered temperature data; The comparison module is used to compare the correlation coefficient with a set threshold, evaluate the cable tensioning quality of the main cable section based on the comparison results, and formulate corresponding handling measures.

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