A cable-replacing safety evaluation and cable-replacing strategy optimization method, system, device and medium for a cable-stayed bridge

Abstract

The application discloses a cable-replacing safety evaluation and cable-replacing strategy optimization method, system, device and medium for a cable-stayed bridge, which comprises the following steps: calculating corresponding basic variable values before and after cable removal in a model under each cable-removing working condition; obtaining a comprehensive influence index value CII under a single pair of cable-removing working condition; taking the comprehensive influence index value CII under the single pair of cable-removing working condition as initial data of K-means clustering analysis, performing clustering analysis, and outputting a clustering result; according to the final clustering result, dividing the cable-stayed cables belonging to the same cluster into the same region to form a region division result; generating a plurality of cable-replacing sequence schemes, selecting corresponding to-be-compared schemes for the cables in different influence regions, respectively calculating the comprehensive influence index values CII under each working condition; and selecting the schemes according to the comprehensive influence index values CII to form an optimal cable-replacing strategy. The application realizes efficient cooperation of cable-stayed cable-replacing safety evaluation, region division and strategy optimization, effectively improves the cable-replacing efficiency while guaranteeing the structural safety.

Description

Technical Field

[0001] This invention belongs to the technical field of bridge safety, and in particular relates to a method, system, equipment and medium for safety assessment and optimization of cable replacement strategies for cable-stayed bridges. Background Technology

[0002] In the safety assessment of cable replacement construction for in-service cable-stayed bridges, the analysis of the cable replacement process often discusses response indicators such as cable force redistribution, main girder deflection, and tower offset in isolation, lacking a comprehensive evaluation system for coupled effects, and failing to establish unified quantitative indicators to measure the comprehensive impact of different cable replacement schemes on the overall structure. Furthermore, traditional zoning methods for cable replacement often rely on static empirical standards such as cable length symmetry and geometric position, failing to quantify the global impact of cable removal on the main girder-tower-remaining cable system, making the zoning results difficult to scientifically guide construction. Simultaneously, the selection of schemes uses independent evaluation of sub-indicators (such as single-point displacement and local stress), lacking a multi-objective collaborative optimization framework, easily leading to decision-making disagreements due to contradictions between indicators, making it difficult to form a globally optimal scheme that balances efficiency and safety. These shortcomings in existing technologies result in a lack of effective support for the safety assessment and strategy optimization of cable replacement construction. Summary of the Invention

[0003] Purpose of the invention: The first purpose of this invention is to provide a method for safety assessment and optimization of cable replacement strategies for cable-stayed bridges. This invention achieves efficient coordination of cable replacement safety assessment, zoning, and strategy optimization, providing a scientific and reliable cable replacement strategy for cable-stayed bridge construction, ensuring structural safety while effectively improving cable replacement efficiency.

[0004] The second objective of this invention is to provide a system for safety assessment and optimization of cable replacement strategies for cable-stayed bridges.

[0005] A third objective of this invention is to provide an electronic device.

[0006] A fourth objective of this invention is to provide a computer-readable storage medium.

[0007] Technical Solution: To achieve the above objectives, this invention discloses a method for safety assessment and optimization of cable replacement strategies for cable-stayed bridges, comprising the following steps:

[0008] (1) Simulate the cable-stayed bridge cable replacement finite element model, and calculate the values ​​of multiple basic variables before and after cable removal in the finite element model under each cable removal condition;

[0009] (2) Standardize the basic variable values ​​under the single cable dismantling condition, calculate the entropy weight of the standardized basic variable, and then combine the standardized basic variable with the entropy weight to calculate the comprehensive influence index value CII under the single cable dismantling condition.

[0010] (3) The comprehensive impact index value under the single cable demolition condition is used as the initial data input for K-means clustering analysis. Set the dataset of comprehensive impact index values; set the number of clusters, and randomly select t comprehensive impact index values ​​from the dataset as the initial cluster centers; calculate the Euclidean distance between each comprehensive impact index value and t centers, and then assign each comprehensive impact index value to the cluster corresponding to the center closest to the comprehensive impact index value.

[0011] (4) For each cluster, recalculate the cluster center point based on all the comprehensive influence index values ​​assigned to that cluster; check whether the change between the new cluster center point and the center point obtained in the previous iteration is less than the preset threshold, or whether the specified number of iterations has been reached. If the conditions are met, stop the iteration and output the clustering result; otherwise, return to step (3) to randomly select t comprehensive influence index values ​​from the dataset as new cluster center points and continue the iteration.

[0012] (5) Based on the final clustering results, the stay cables belonging to the same cluster are divided into the same area to form the partitioning results; based on the stay cable partitioning results and construction time requirements, a variety of cable replacement schemes are initially proposed. Among the various cable replacement schemes, priority is given to arranging multiple pairs of cables to be replaced in the cable area with low cable removal impact, and single pairs of cables are given priority to be replaced in the cable area with high cable removal impact, generating a variety of cable replacement sequence schemes. Each cable replacement sequence scheme is marked with the cable number, location and corresponding impact area level of each batch of replacements.

[0013] (6) Select the corresponding alternative schemes for cables in different influence areas from multiple cable replacement sequence schemes, simulate all working conditions of all alternative schemes to obtain basic variables, and calculate the comprehensive influence index (CII) values ​​for single-pair cable dismantling and multi-pair cable dismantling working conditions respectively.

[0014] (7) Assess the degree of risk dispersion based on the coefficient of variation, which is the ratio of the standard deviation of CII to the mean of CII, and use a set threshold to count the proportion of out-of-limit working conditions; prioritize the scheme with the lowest mean of CII, small coefficient of variation and proportion of out-of-limit working conditions approaching zero, and use the daily average cable replacement efficiency as the decisive indicator for candidate schemes with similar mean of CII; finally, verify the significance probability p value through the F statistic to ensure the mechanical response coordination of the schemes in each affected area, and form the optimal cable replacement strategy.

[0015] Optionally, the multiple basic variables in step (1) include the vertical displacement of the main beam. Longitudinal deviation of bridge tower and rate of change of cable force The vertical displacement of the main beam This refers to the maximum change in vertical displacement of key nodes of the main girder after cable removal, reflecting the deformation caused by local stiffness loss; longitudinal displacement of the bridge tower. This refers to the change in longitudinal displacement at the top of the bridge tower after cable removal, reflecting the main tower's misalignment and stability; cable force change rate. It refers to the maximum rate of change of cable force in the remaining cables after a pair of stay cables are removed.

[0016] Optionally, in steps (2) and (6), the linear range standardization method is used to perform standardized calculations of the basic variables under a single-pair substitution.

[0017] ,

[0018] in, Let j be the standard value of the j-th basic variable under the i-th working condition. Let be the original value of the j-th basic variable under the i-th working condition. For the first The maximum value of each basic variable under all operating conditions. For the first The minimum value of each basic variable under all operating conditions.

[0019] Optionally, in steps (2) and (6), the static weight coefficient calculation method is used to calculate the entropy weight of the basic variables under a single-pair replacement, that is, to calculate the proportion of the j-th basic variable under the i-th working condition respectively. The entropy value of the j-th basic variable and the Entropy weights of the basic variables ;

[0020] ,

[0021] ,

[0022] ,

[0023] Where m represents the number of all operating conditions. , .

[0024] Optionally, the specific formula for calculating the Comprehensive Impact Index (CII) in steps (2) and (6) is as follows:

[0025] ,

[0026] in, Let j be the standard value of the j-th basic variable under the i-th working condition. Let i be the entropy weight of the j-th basic variable, i = 1, 2, ..., m, where i represents the cable dismantling condition. M refers to the basic variable, and M is the number of values ​​for the basic variable.

[0027] Optionally, in step (6), a nonlinear range standardization method is used to perform standardized calculations of the basic variables under multiple cable replacements;

[0028] ,

[0029] in, The curvature adjustment parameters were determined through fitting experiments. Let j be the standard value of the j-th basic variable under the i-th working condition. Let be the original value of the j-th basic variable under the i-th working condition. Let be the mean of the j-th basic variable. Let be the standard deviation of the j-th basic variable.

[0030] Optionally, in step (6), the dynamic weight coefficient calculation method is used to calculate the entropy weight of the basic variable under multiple pair replacements, that is, the data is first layered and a correlation function between the split pair logarithm and the weight coefficient is established.

[0031] ,

[0032] in, This represents the number of simultaneous decompositions of the hops. For the corresponding level;

[0033] Calculate the proportion of the j-th basic variable in each level under the i-th multi-pair cable replacement condition. and the Hierarchical information entropy of basic variables ;

[0034] ,

[0035] ,

[0036] ,

[0037] Change the number of working conditions for multiple pairs of cables within each level;

[0038] Finally, the weights are synthesized, and the final weights are obtained by linear interpolation between levels according to the following formula;

[0039] ,

[0040] in, This is a dynamic adjustment coefficient, effective when n≤2. For hierarchical entropy weights, The global entropy weights, , Replace the entropy weight of the j-th basic variable for a single pair of indices; when n≥3, directly use the entropy weight of level 3, i.e. .

[0041] Based on the same inventive concept, the present invention provides a cable-stayed bridge cable replacement safety assessment and cable replacement strategy optimization system, comprising:

[0042] The basic variable calculation module is used to simulate the cable removal condition of a single cable pair in the finite element model of cable-stayed bridge cable replacement, and calculate the corresponding values ​​of multiple basic variables in the finite element model before and after cable removal under various cable removal conditions.

[0043] The single-pair cable index calculation module is used to standardize the basic variable values ​​under the single-pair cable dismantling condition, calculate the entropy weight of the standardized basic variable, and then combine the standardized basic variable with the entropy weight to calculate the comprehensive influence index value CII under the single-pair cable dismantling condition.

[0044] The clustering analysis module is used to take the comprehensive impact index value under the single-pair cable demolition condition as the initial data input for K-means clustering analysis. The module sets the dataset of comprehensive impact index values, sets the number of clusters, and randomly selects t comprehensive impact index values ​​from the dataset as the initial cluster centroids. It then calculates the Euclidean distance between each comprehensive impact index value and the t centroids, and assigns each comprehensive impact index value to the cluster corresponding to the centroid closest to it.

[0045] The clustering result output module is used to recalculate the cluster centroids for each cluster based on all the comprehensive influence index values ​​assigned to that cluster; check whether the change between the new cluster centroids and the centroids obtained in the previous iteration is less than a preset threshold, or whether the specified number of iterations has been reached. If the conditions are met, the iteration stops and the clustering result is output; otherwise, it returns to the clustering analysis module to randomly select t comprehensive influence index values ​​from the dataset as new cluster centroids and continues the iteration.

[0046] The feasibility scheme generation module is used to divide the stay cables belonging to the same cluster into the same area based on the final clustering results, forming a partitioning result. Based on the stay cable partitioning result and construction time requirements, a number of cable replacement schemes are initially proposed. Among the multiple cable replacement schemes, priority is given to arranging the centralized replacement of multiple pairs of cables in cable areas with low cable removal impact, and single pair cable replacement is given priority in cable areas with high cable removal impact. Multiple cable replacement sequence schemes are generated, and each cable replacement sequence scheme is marked with the cable number, location and corresponding impact area level of each batch of replacement.

[0047] The cable replacement scheme index value calculation module is used to select the corresponding candidate schemes for cables in different influence areas among multiple cable replacement sequence schemes, simulate all working conditions of all candidate schemes to obtain basic variables, and calculate the comprehensive influence index value CII under single cable dismantling working conditions and multiple cable dismantling working conditions respectively.

[0048] The cable replacement scheme screening module is used to assess the degree of risk dispersion based on the coefficient of variation, which is the ratio of the standard deviation of the CII to the mean of the CII. The module also uses a set threshold to statistically analyze the proportion of out-of-limit working conditions. The module prioritizes the scheme with the lowest mean CII, the smallest coefficient of variation, and the proportion of out-of-limit working conditions approaching zero. For candidate schemes with similar mean CII, the daily average cable replacement efficiency is used as the deciding indicator. Finally, the significance probability p-value is verified by the F-statistic to ensure the coordination of the mechanical response of the schemes in each affected area, thus forming the optimal cable replacement strategy.

[0049] Based on the same inventive concept, the present invention provides an electronic device including a processor and a storage medium;

[0050] The storage medium is used to store instructions;

[0051] The processor is configured to operate according to the instructions to perform the steps of the method described above.

[0052] Based on the same inventive concept, the computer-readable storage medium of the present invention stores a computer program thereon, characterized in that the program, when executed by a processor, implements the steps of the method described above.

[0053] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0054] (1) This invention constructs an integrated method system for safety assessment of cable replacement, cable impact zoning and cable replacement strategy optimization, which breaks through the limitations of traditional methods in the case of inaccurate assessment and disconnect between zoning and strategy under multiple cable replacement conditions;

[0055] (2) This invention effectively addresses extreme value interference by processing basic variables through hierarchical standardization, thereby improving the ability to identify differences in mechanical response. Compared with traditional homogenization and standardization strategies, this invention significantly improves the reliability of the assessment.

[0056] (3) This invention proposes a static and dynamic coupled weight calculation framework, which fully considers the time-varying sensitivity of basic variables in the replacement of multiple pairs of group cables, solves the problem of inaccurate weight allocation in the traditional entropy weight method, and makes the weight coefficients accurately match the actual contribution of the mechanical response.

[0057] (4) This invention combines K-means clustering analysis with the comprehensive influence index CII to partition the cable and dynamically optimize the cable replacement scheme based on the partitioning results. This changes the situation where the existing partitioning method and cable replacement scheme selection are disconnected, avoids resource waste and safety redundancy, and realizes the scientific planning of construction sequence.

[0058] (5) This invention tests the overall significant difference between multiple schemes by calculating the F statistic and the significance probability p value, ensuring the mechanical state balance between groups and avoiding misjudgment of the cable replacement scheme in high-risk areas. Compared with the traditional method without statistical testing, it greatly improves the safety and reliability of the cable replacement strategy.

[0059] (6) This invention realizes the organic synergy of cable-stayed bridge cable replacement safety assessment, zoning and strategy optimization, providing a scientific, efficient and safe solution for cable replacement construction, ensuring structural safety while significantly improving the efficiency of cable group replacement. Attached Figure Description

[0060] Figure 1 This is a flowchart of the present invention;

[0061] Figure 2 This is a simplified finite element model diagram of the cable-stayed bridge of the present invention. Detailed Implementation

[0062] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0063] like Figure 1 and Figure 2 As shown, the present invention provides a method for safety assessment and optimization of cable replacement strategies for cable-stayed bridges, comprising the following steps:

[0064] (1) Simulate the cable-stayed bridge cable replacement finite element model for single-pair cable removal, and calculate the values ​​of multiple basic variables before and after cable removal in the finite element model under each cable removal condition; among which, multiple basic variables include the vertical displacement of the main beam. Longitudinal deviation of bridge tower and rate of change of cable force The vertical displacement of the main beam This refers to the maximum change in vertical displacement of key nodes of the main girder after cable removal, reflecting the deformation caused by local stiffness loss; longitudinal displacement of the bridge tower. This refers to the change in longitudinal displacement at the top of the bridge tower after cable removal, reflecting the main tower's misalignment and stability; cable force change rate. This refers to the rate of change of the maximum cable force in the remaining cables after a pair of stay cables has been removed.

[0065] ,

[0066] in, For the cable tension before dismantling, For the cable force after dismantling, The number of cable dismantling conditions is shown in Table 1. The results of the three basic variable values ​​under the single cable dismantling condition are shown in Table 1.

[0067] Table 1 Basic Variable Values ​​for Cable Removal Conditions

[0068]

[0069] (2) The linear range standardization method is used to standardize the basic variable values ​​under single cable replacement, and the static weight coefficient calculation method is used to calculate the entropy weight of the basic variable under single cable replacement. The standardized basic variable is combined with the calculated entropy weight to calculate the comprehensive influence index (CII) under the single cable dismantling condition.

[0070] The linear range standardization method was used to perform standardized calculations of the basic variables under a single pair of cable replacements.

[0071] ,

[0072] in, Let j be the standard value of the j-th basic variable under the i-th working condition. Let be the original value of the j-th basic variable under the i-th working condition. For the first The maximum value of each basic variable under all operating conditions. For the first The minimum value of each basic variable under all operating conditions.

[0073] The static weighting coefficient calculation method is used to calculate the entropy weight of the basic variables under a single cable replacement, that is, to calculate the proportion of the j-th basic variable under the i-th working condition. The entropy value of the j-th basic variable and the Entropy weights of the basic variables ;

[0074] ,

[0075] ,

[0076] ,

[0077] Where m represents the number of all operating conditions. , The calculated static entropy weights are as follows: , , .

[0078] The specific formula for calculating the Comprehensive Impact Index (CII) of cable removal is as follows:

[0079] ,

[0080] in, Let j be the standard value of the j-th basic variable under the i-th working condition. Let i be the entropy weight of the j-th basic variable, i = 1, 2, ..., m, where i represents the cable dismantling condition. 3 refers to the basic variable, and 3 is the number of basic variable values. The calculation results are shown in Table 2.

[0081] Table 2 Comprehensive Impact Index Values

[0082] (3) The calculated comprehensive impact index under the single-pair cable removal condition is used as the initial data input for K-means clustering analysis. Let the dataset of comprehensive impact index values ​​be... Where m is the total number of working conditions, i.e., the logarithm of the stay cables; the number of clusters is set to 3, and t comprehensive influence index values ​​are randomly selected from the dataset as the initial cluster centers. ; Calculate the Euclidean distance between each comprehensive influence index and t center points. Then They are assigned to the cluster corresponding to the center point closest to the comprehensive influence index.

[0083] ,

[0084] (4) For each cluster, recalculate the cluster centroid based on all the composite influence index values ​​assigned to that cluster.

[0085] ,

[0086] in, For the j-th cluster, a new set of data points is generated. The change between the new cluster center point and the center point obtained in the previous iteration is checked to see if it is less than a preset threshold or if the specified number of iterations has been reached. If the termination condition is met, the iteration is stopped and the clustering result is output. Otherwise, the process returns to step (3) to randomly select t comprehensive influence index values ​​from the dataset as new cluster centers and continues iterating. The termination condition can be set to the center offset of adjacent iterations being less than... Or it can reach the maximum number of iterations of 300.

[0087] (5) Based on the final clustering results, the stay cables belonging to the same cluster are divided into the same area, thus completing the zoning of the stay cables; based on the zoning results of the stay cables, and according to the time requirements of construction organization, a variety of cable replacement schemes are initially proposed. Among the various cable replacement schemes, priority is given to arranging multiple pairs of cables to be replaced in the cable area with lower cable removal impact, and single pairs of cables are given priority to be replaced in the cable area with higher cable removal impact. At the same time, the turnover efficiency of construction equipment and traffic control requirements are considered to generate a variety of cable replacement sequence schemes. Each cable replacement sequence scheme clearly marks the cable number, location and corresponding impact area level of each batch of replacements; the zoning results are shown in Table 3.

[0088] Table 3 Partition Results

[0089]

[0090] Based on the different number and location of cable replacements, four schemes were considered for this bridge: Scheme 1 is the test cable replacement scheme, which involves replacing two stay cables with the same numerical number on both sides of the bridge tower on the upstream and downstream sides at once; Scheme 2 is to replace two pairs (4 cables) of stay cables with the same numerical number on both sides of the bridge tower on the upstream and downstream sides at once; Scheme 3 is to replace two pairs (4 cables) of stay cables with adjacent numerical numbers on both sides of the bridge tower on the upstream and downstream sides at once; Scheme 4 is to replace four pairs (8 cables) of stay cables with adjacent numerical numbers on both sides of the bridge tower on the upstream and downstream sides at once.

[0091] (6) Select the corresponding alternative schemes for cables in different influence areas from the multiple cable replacement sequence schemes, simulate all working conditions of all alternative schemes to obtain basic variables, calculate the comprehensive influence index (CII) value under all working conditions, that is, calculate the comprehensive influence index (CII) value under the single cable dismantling working condition according to step (2), then use the nonlinear range standardization method to standardize the basic variable values ​​under multiple cable replacement, use the dynamic weight coefficient calculation method to calculate the entropy weight of the basic variables under multiple cable replacement, combine the standardized basic variables with the calculated entropy weight, and calculate the comprehensive influence index (CII) value under the multiple cable dismantling working condition.

[0092] The nonlinear range standardization method is used to perform standardized calculations of basic variables under multiple cable replacements;

[0093] ,

[0094] in, The curvature adjustment parameters were determined through fitting experiments. Let j be the standard value of the j-th basic variable under the i-th working condition. Let be the original value of the j-th basic variable under the i-th working condition. Let be the mean of the j-th basic variable. Let be the standard deviation of the j-th basic variable.

[0095] Then, the dynamic weight coefficient calculation method is used to calculate the entropy weight of the basic variable under multiple index replacements. That is, the data is first layered and a correlation function between the index logarithm and the weight coefficient is established.

[0096] ,

[0097] in, This represents the number of simultaneous decompositions of the hops. For the corresponding level;

[0098] Calculate the proportion of the j-th basic variable in each level under the i-th multi-pair cable replacement condition. and the Hierarchical information entropy of basic variables ;

[0099] ,

[0100] ,

[0101] ,

[0102] Change the number of working conditions for multiple pairs of cables within each level;

[0103] Finally, the weights are synthesized, and the final weights are obtained by linear interpolation between levels according to the following formula;

[0104] ,

[0105] in, This is a dynamic adjustment coefficient, effective when n≤2. For hierarchical entropy weights, The global entropy weights, , Replace the entropy weight of the j-th basic variable for a single pair of indices; when n≥3, directly use the entropy weight of level 3, i.e. .

[0106] The standardized basic variables are combined with the calculated entropy weights to calculate the comprehensive impact index (CII) under multiple cable replacements.

[0107] ,

[0108] in, Let j be the standard value of the j-th basic variable under the i-th working condition. Let i be the entropy weight of the j-th basic variable, i = 1, 2, ..., n, where i represents the cable dismantling condition. Refers to the basic variable.

[0109] (7) Assess the degree of risk dispersion based on the coefficient of variation, which is the ratio of the standard deviation of CII to the mean. Calculate the proportion of out-of-limit working conditions using a set threshold. Prioritize the scheme with the lowest mean CII, small coefficient of variation, and a proportion of out-of-limit working conditions approaching zero. For candidate schemes with similar mean CII, use the average daily cable replacement efficiency as the deciding indicator. Finally, verify the significance probability p-value using the F-statistic to ensure the mechanical response coordination of schemes in high, medium, and low impact areas, forming the optimal cable replacement strategy that is safe, controllable, risk-balanced, and efficient in construction. Using the mean CII as the core indicator, select corresponding cable replacement schemes for each impact area. Finally, determine that scheme 1 is used for cable replacement in high impact areas, scheme 2 is used in medium impact areas, and scheme 4 is used in low impact areas.

[0110] Specifically, the mean fluctuation of CII under all operating conditions for each affected area is defined as the within-group variance, and the mean fluctuation of CII under all operating conditions for each of the three affected areas is defined as the between-group variance. The F-statistics of the between-group and within-group variances are calculated to test the overall significant difference among multiple schemes. The significance probability p-value is calculated, and the null hypothesis is accepted when the significance level p > 0.05, indicating that the mechanical states of each scheme are in equilibrium. The ANOVA test shows that the p-value is 0.15. At common significance levels (such as 0.05), this p-value is greater than the significance level, indicating that there is no significant difference in CII values ​​among the high, medium, and low affected areas overall.

[0111] This invention simulates single-pair and / or multiple-pair cable removal scenarios, calculating three fundamental variables: vertical displacement of the main girder, longitudinal displacement of the bridge tower, and cable force change rate. It employs hierarchical standardization (linear range standardization for single-pair cable removal and nonlinear range standardization for multiple-pair cable removal) to address extreme value interference. Based on the entropy weight method, this invention constructs a static-dynamic coupled weight calculation framework (static weights for single-pair cable removal and dynamic weights combined with the logarithm of cable removal for multi-pair cable removal), objectively quantifying the importance of fundamental variables. This invention uses the comprehensive influence index (CII) of single-pair cable removal as input for K-means clustering analysis to complete cable-stayed bridge partitioning. Based on the partitioning results, cable replacement schemes are proposed, calculating CII values ​​and using the mean CII as the core indicator for scheme selection. This invention verifies the overall significant differences among multiple schemes by calculating the F-statistic of the variances between and within groups and the significance probability p-value (p>0.05 indicates mechanical equilibrium). This invention breaks through the limitations of traditional methods and solves problems such as inaccurate weight allocation, low evaluation reliability, and disconnect between zoning and scheme. It achieves efficient collaboration in cable-stayed bridge cable replacement safety assessment, zoning, and strategy optimization, providing a scientific and reliable solution for cable-stayed bridge cable replacement construction, ensuring structural safety and improving cable replacement efficiency.

[0112] Example 2: A cable-stayed bridge cable replacement safety assessment and cable replacement strategy optimization system of the present invention includes:

[0113] The basic variable calculation module is used to simulate the cable removal conditions of a single pair of stay cables in the finite element model of a cable-stayed bridge. It calculates the corresponding values ​​of multiple basic variables before and after cable removal in the finite element model under various cable removal conditions. The multiple basic variables include the vertical displacement ΔV of the main girder, the longitudinal displacement ΔL of the bridge tower, and the cable force change rate ΔT. Among them, the vertical displacement ΔV of the main girder refers to the maximum change value of the vertical displacement of the key nodes of the main girder after cable removal, reflecting the deformation caused by local stiffness loss; the longitudinal displacement ΔL of the bridge tower refers to the change value of the longitudinal displacement of the top of the bridge tower after cable removal, reflecting the main tower displacement and stability; the cable force change rate ΔT refers to the maximum cable force change rate of the remaining cables after the removal of a certain pair of stay cables.

[0114] The single-pair cable index calculation module is used to standardize the basic variable values ​​under the single-pair cable dismantling condition, calculate the entropy weight of the standardized basic variable, and then combine the standardized basic variable with the entropy weight to calculate the comprehensive influence index value CII under the single-pair cable dismantling condition.

[0115] The linear range standardization method was used to perform standardized calculations of the basic variables under a single pair of substitutions;

[0116] ,

[0117] in, Let j be the standard value of the j-th basic variable under the i-th working condition. Let be the original value of the j-th basic variable under the i-th working condition. For the first The maximum value of each basic variable under all operating conditions. For the first The minimum value of each basic variable under all operating conditions.

[0118] The entropy weights of the basic variables under a single-pair cable replacement are calculated using a static weighting coefficient calculation method, that is, the proportion of the j-th basic variable under the i-th working condition is calculated respectively. The entropy value of the j-th basic variable and the Entropy weights of the basic variables ;

[0119] ,

[0120] ,

[0121] ,

[0122] Where m represents the number of all operating conditions. , .

[0123] The specific formula for calculating the Comprehensive Impact Index (CII) of cable removal is as follows:

[0124] ,

[0125] in, Let j be the standard value of the j-th basic variable under the i-th working condition. Let i be the entropy weight of the j-th basic variable, i = 1, 2, ..., m, where i represents the cable dismantling condition. M refers to the basic variable, and M is the number of values ​​for the basic variable.

[0126] The clustering analysis module is used to take the comprehensive impact index value under the single-pair cable demolition condition as the initial data input for K-means clustering analysis. Set the dataset of comprehensive impact index values; set the number of clusters; randomly select t comprehensive impact index values ​​from the dataset as the initial cluster centroids; calculate the Euclidean distance between each comprehensive impact index value and the t centroids; and then assign each comprehensive impact index value to the cluster corresponding to the centroid closest to the comprehensive impact index value.

[0127] The clustering result output module is used to recalculate the cluster centroids for each cluster based on all the comprehensive influence index values ​​assigned to that cluster; check whether the change between the new cluster centroids and the centroids obtained in the previous iteration is less than a preset threshold, or whether the specified number of iterations has been reached. If the conditions are met, the iteration stops and the clustering result is output; otherwise, return to the clustering analysis module to randomly select t comprehensive influence index values ​​from the dataset as new cluster centroids and continue the iteration.

[0128] The feasibility scheme formation module is used to divide the stay cables belonging to the same cluster into the same area based on the final clustering results, forming a partitioning result. Based on the stay cable partitioning result and construction time requirements, a number of cable replacement schemes are initially proposed. Among the multiple cable replacement schemes, priority is given to arranging the centralized replacement of multiple pairs of cables in cable areas with low cable removal impact, and single pair cable replacement is given priority in cable areas with high cable removal impact. Multiple cable replacement sequence schemes are generated, and each cable replacement sequence scheme is marked with the cable number, location and corresponding impact area level of each batch of replacement.

[0129] The cable replacement scheme index calculation module is used to select the corresponding candidate schemes for cables in different influence areas among multiple cable replacement sequence schemes, simulate all working conditions of all candidate schemes to obtain basic variables, and calculate the comprehensive influence index (CII) under single-pair cable dismantling and multi-pair cable dismantling working conditions respectively.

[0130] A nonlinear range standardization method is used to perform standardized calculations of basic variables under multiple cable replacements;

[0131] ,

[0132] in, The curvature adjustment parameters were determined through fitting experiments. Let j be the standard value of the j-th basic variable under the i-th working condition. Let be the original value of the j-th basic variable under the i-th working condition. Let be the mean of the j-th basic variable. Let be the standard deviation of the j-th basic variable.

[0133] The entropy weights of the basic variables under multiple index replacements are calculated using a dynamic weight coefficient calculation method. This involves first performing data stratification and establishing a correlation function between the index logarithm and the weight coefficient.

[0134] ,

[0135] in, This represents the number of simultaneous decompositions of the hops. This corresponds to the level.

[0136] Calculate the proportion of the j-th basic variable in each level under the i-th multi-pair cable replacement condition. and the Hierarchical information entropy of basic variables ;

[0137] ,

[0138] ,

[0139] ,

[0140] Change the number of working conditions for multiple pairs of cables within each level;

[0141] Finally, the weights are synthesized, and the final weights are obtained by linear interpolation between levels according to the following formula;

[0142]

[0143] in, This is a dynamic adjustment coefficient, effective when n≤2. For hierarchical entropy weights, The global entropy weights, , Replace the entropy weight of the j-th basic variable for a single pair of indices; when n≥3, directly use the entropy weight of level 3, i.e. .

[0144] The cable replacement scheme screening module is used to assess the degree of risk dispersion based on the coefficient of variation, which is the ratio of the standard deviation of the CII to the mean of the CII. The module also uses a set threshold to statistically analyze the proportion of out-of-limit working conditions. The module prioritizes the scheme with the lowest mean CII, the smallest coefficient of variation, and the proportion of out-of-limit working conditions approaching zero. For candidate schemes with similar mean CII, the daily average cable replacement efficiency is used as the deciding indicator. Finally, the significance probability p-value is verified by the F-statistic to ensure the coordination of the mechanical response of the schemes in each affected area, thus forming the optimal cable replacement strategy.

[0145] Example 3: An electronic device of the present invention includes a processor and a storage medium;

[0146] The storage medium is used to store instructions;

[0147] The processor is configured to operate according to the instructions to perform the steps of the method described above.

[0148] Example 4: The computer-readable storage medium of the present invention stores a computer program thereon, which, when executed by a processor, implements the steps of the method described above.

Claims

1. A method for cable replacement safety assessment and cable replacement strategy optimization of a cable-stayed bridge, characterized in that, Includes the following steps: (1) Simulate the cable-stayed bridge cable replacement finite element model, and calculate the values ​​of multiple basic variables before and after cable removal in the finite element model under each cable removal condition. (2) Standardize the basic variable values ​​under the single cable dismantling condition, calculate the entropy weight of the standardized basic variable, and then combine the standardized basic variable with the entropy weight to calculate the comprehensive influence index value CII under the single cable dismantling condition. (3) The comprehensive impact index value under the single cable removal condition is used as the initial data input for K-means clustering analysis. Let the dataset of comprehensive impact index values ​​be set. Set the number of clusters, and randomly select t comprehensive influence index values ​​from the dataset as the initial cluster centers; Calculate the Euclidean distance between each comprehensive impact index value and t center points, and then assign each comprehensive impact index value to the cluster corresponding to the center point closest to the comprehensive impact index value; (4) For each cluster, recalculate the cluster center point based on all the comprehensive influence index values ​​assigned to that cluster; check whether the change between the new cluster center point and the center point obtained in the previous iteration is less than the preset threshold, or whether the specified number of iterations has been reached. If the conditions are met, stop the iteration and output the clustering results. Otherwise, return to step (3) and randomly select t comprehensive influence index values ​​from the dataset as new cluster centers, and continue iterating; (5) Based on the final clustering results, the stay cables belonging to the same cluster are divided into the same area to form a partitioning result; based on the stay cable partitioning result and construction time requirements, a variety of cable replacement schemes are initially proposed. Among the various cable replacement schemes, priority is given to arranging multiple pairs of cables to be replaced in cable areas with low cable removal impact, and single pairs of cables are given priority to be replaced in cable areas with high cable removal impact, generating a variety of cable replacement sequence schemes. Each cable replacement sequence scheme is marked with the cable number, location and corresponding impact area level of each batch of replacements. (6) Select appropriate alternatives for cables in different influence areas from multiple cable replacement sequence schemes, simulate all working conditions of all alternatives to obtain basic variables, and calculate the comprehensive influence index (CII) under single-pair cable dismantling and multi-pair cable dismantling working conditions respectively. (7) Assess the degree of risk dispersion based on the coefficient of variation, which is the ratio of the standard deviation of CII to the mean of CII, and use a set threshold to count the proportion of out-of-limit working conditions; prioritize the scheme with the lowest mean of CII, small coefficient of variation and proportion of out-of-limit working conditions approaching zero, and use the daily average cable replacement efficiency as the decisive indicator for candidate schemes with similar mean of CII; finally, verify the significance probability p value through the F statistic to ensure the mechanical response coordination of the schemes in each affected area, and form the optimal cable replacement strategy.

2. The cable replacement safety evaluation and strategy optimization method of a cable-stayed bridge according to claim 1, characterized in that: In step (1), several basic variables include the vertical displacement ΔV of the main beam, the longitudinal displacement ΔL of the bridge tower, and the cable force change rate ΔT. The vertical displacement ΔV of the main beam refers to the maximum change in vertical displacement of the key nodes of the main beam after the cables are removed, reflecting the deformation caused by local stiffness loss. The longitudinal displacement ΔL of the bridge tower refers to the change in longitudinal displacement of the top of the bridge tower after the cables are removed, reflecting the displacement and stability of the main tower. The cable force change rate ΔT refers to the maximum cable force change rate among the remaining cables after a pair of stay cables are removed.

3. The method for safety assessment and optimization of cable replacement strategy for cable-stayed bridges according to claim 1, characterized in that: In steps (2) and (6), the linear range standardization method is used to perform standardized calculations of the basic variables under a single-pair substitution. Among them, y ij Let x be the standard value of the j-th basic variable under the i-th working condition. ij Let be the original value of the j-th basic variable under the i-th working condition. Let j be the maximum value of the j-th basic variable across all operating conditions. Let j be the minimum value of the j-th basic variable across all operating conditions.

4. The cable replacement safety evaluation and cable replacement strategy optimization method of a cable-stayed bridge according to claim 3, characterized in that: In steps (2) and (6), the static weight coefficient calculation method is used to calculate the entropy weight of the basic variables under a single-pair replacement, that is, to calculate the proportion d of the j-th basic variable under the i-th working condition. ij The entropy value e of the j-th basic variable j and the entropy weight w of the j-th basic variable j ; where m is the number of all working conditions, h = 1 / ln m, 0 < e j ≤ 1.

5. The cable replacement safety evaluation and strategy optimization method of a cable-stayed bridge according to claim 4, characterized in that: The specific formula for calculating the Comprehensive Impact Index (CII) in steps (2) and (6) is as follows: Among them, y ij w represents the standard value of the j-th basic variable under the i-th working condition. j Let be the entropy weight of the j-th basic variable, i = 1, 2, ..., m, where i represents the cable dismantling condition, j refers to the basic variable, and M is the number of basic variable values.

6. The cable replacement safety evaluation and cable replacement strategy optimization method of a cable-stayed bridge according to claim 1, characterized in that: In step (6), a nonlinear range standardization method is used to perform standardized calculations of the basic variables under multiple cable replacements; Where k is the curvature adjustment parameter determined through fitting experiments, and y ij Let x be the standard value of the j-th basic variable under the i-th working condition. ij μ represents the original value of the j-th basic variable under the i-th working condition. j Let σ be the mean of the j-th basic variable. j Let be the standard deviation of the j-th basic variable.

7. The method according to claim 6, wherein: In step (6), the dynamic weight coefficient calculation method is used to calculate the entropy weight of the basic variable under multiple pair replacements, that is, the data is first layered and a correlation function between the split pair logarithm and the weight coefficient is established. Where n represents the number of simultaneous decomposition pairs, and s(n) is the corresponding level; calculating the proportion of the jth basic variable in each level under the ith multiple pair cable replacement working condition and the level information entropy of the jth basic variable m s replace the number of working conditions for each pair of cables within each level; Finally, the weights are synthesized, and the final weights are obtained by linear interpolation between levels according to the following formula; Where λ(n) = 0.2n is the dynamic adjustment coefficient, which is effective when n ≤ 2, w j (s) For hierarchical entropy weights, The global entropy weights, w j Replace the entropy weight of the j-th basic variable for a single pair of variables; when n≥3, directly use the entropy weight of level 3, i.e., w. j (n)=w j (s) .

8. A system for safety assessment and optimization of cable replacement strategies for cable-stayed bridges, characterized in that, include: The basic variable calculation module is used to simulate the cable removal condition of a single cable pair in the finite element model of cable-stayed bridge cable replacement, and calculate the corresponding values ​​of multiple basic variables in the finite element model before and after cable removal under various cable removal conditions. The single-pair cable index calculation module is used to standardize the basic variable values ​​under the single-pair cable dismantling condition, calculate the entropy weight of the standardized basic variable, and then combine the standardized basic variable with the entropy weight to calculate the comprehensive influence index value CII under the single-pair cable dismantling condition. The clustering analysis module is used to take the comprehensive impact index value under the single cable removal condition as the initial data input for K-means clustering analysis. Let the dataset of comprehensive impact index values ​​be set. Set the number of clusters, and randomly select t comprehensive influence index values ​​from the dataset as the initial cluster centers; Calculate the Euclidean distance between each comprehensive impact index value and t center points, and then assign each comprehensive impact index value to the cluster corresponding to the center point closest to the comprehensive impact index value; The clustering result output module is used to recalculate the cluster centroids for each cluster based on all the comprehensive influence index values ​​assigned to that cluster; check whether the change between the new cluster centroids and the centroids obtained in the previous iteration is less than a preset threshold, or whether the specified number of iterations has been reached. If the conditions are met, the iteration is stopped and the clustering results are output. Otherwise, return to the cluster analysis module and randomly select t comprehensive influence index values ​​from the dataset as new cluster centers, and continue iterating; The feasibility scheme generation module is used to divide the stay cables belonging to the same cluster into the same area based on the final clustering results, forming a partitioning result. Based on the stay cable partitioning result and construction time requirements, a number of cable replacement schemes are initially proposed. Among the multiple cable replacement schemes, priority is given to arranging the centralized replacement of multiple pairs of cables in cable areas with low cable removal impact, and single pair cable replacement is given priority in cable areas with high cable removal impact. Multiple cable replacement sequence schemes are generated, and each cable replacement sequence scheme is marked with the cable number, location and corresponding impact area level of each batch of replacement. The cable replacement scheme index value calculation module is used to select the corresponding candidate schemes for cables in different influence areas among multiple cable replacement sequence schemes, simulate all working conditions of all candidate schemes to obtain basic variables, and calculate the comprehensive influence index value CII under single-pair cable dismantling working conditions and multi-pair cable dismantling working conditions respectively. The cable replacement scheme screening module is used to assess the degree of risk dispersion based on the coefficient of variation, which is the ratio of the standard deviation of the CII to the mean of the CII. The module also uses a set threshold to statistically analyze the proportion of out-of-limit working conditions. The module prioritizes the scheme with the lowest mean CII, the smallest coefficient of variation, and the proportion of out-of-limit working conditions approaching zero. For candidate schemes with similar mean CII, the daily average cable replacement efficiency is used as the deciding indicator. Finally, the significance probability p-value is verified by the F-statistic to ensure the coordination of the mechanical response of the schemes in each affected area, thus forming the optimal cable replacement strategy.

9. An electronic device, comprising: Including processor and storage media; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, When executed by a processor, the program implements the steps of the method according to any one of claims 1 to 7.

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