Cable-stayed bridge monitoring method and system based on cable force and bridge deck acceleration

Abstract

The present invention discloses a monitoring method and system for a cable-stayed bridge based on cable force and bridge deck acceleration, the method comprising the steps of: selecting a number of paired cables as monitoring cables on a target cable-stayed bridge, and obtaining the cable force and sag of the monitoring cables; selecting a section perpendicular to the connection between the bridge deck and the monitoring cables on the target cable-stayed bridge as a monitoring section, and obtaining the vibration characteristics of the monitoring section; constructing and training a monitoring model based on a supervised neural network; inputting the cable force and sag of each monitoring cable and the vibration characteristics of each monitoring section into the trained monitoring model, and obtaining an evaluation result of whether the target cable-stayed bridge has a risk of damage. The present invention comprehensively monitors the three coupling indicators of cable force, cable sag and bridge deck vibration of the cable-stayed bridge, and can timely detect vortex vibration and resonance of the cable-stayed bridge, and evaluate the damage risk of the bridge, making up for the problems of the existing technology of single monitoring indicators, low monitoring data accuracy, low reliability, and lack of verification of other indicators.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge structure monitoring, and in particular to a monitoring method and system for a cable-stayed bridge based on cable force and bridge deck acceleration. Background Art

[0002] For cable-stayed bridges, the stiffness and load-bearing capacity of the bridge deck structure are usually low, especially in the case of large spans. This design feature results in the main loads of the bridge being borne by multiple cables. The robustness of the cables, that is, their ability to maintain performance in the face of adverse conditions, becomes a key factor in ensuring the safe performance of the entire bridge structure. It is important to note that the cables in a cable-stayed bridge do not work independently; the forces exerted on each cable are affected by the other cables in the bridge and also have an impact on the other cables. This interdependence means that if one or more cables fail, it may lead to a redistribution of internal forces in the entire cable-stay system, which may trigger a "button-unbuttoning" effect that leads to the failure of the cable-stay system and even the entire cable-stayed bridge.

[0003] Therefore, it is particularly important to effectively monitor the cable-stayed system during the normal operation of the cable-stayed bridge. This monitoring aims to timely discover and diagnose potential structural problems to ensure that the bridge can operate safely and reliably within its designed service life. Through such monitoring and maintenance strategies, structural failures can be effectively prevented to ensure the long-term stability and safety of the cable-stayed bridge.

[0004] In terms of the dynamic response of cable-stayed bridges, bridge vibration is a normal phenomenon. These vibrations may be caused by a variety of factors, including traffic loads, wind loads, temperature changes, etc. There are many vibration modes, such as flutter, buffeting, galloping and vortex vibration. Among them, flutter, buffeting and galloping, although common, usually have little effect on the overall safety performance and service life of the bridge. In contrast, vortex vibration is a special type of vibration, which is a wind-induced vibration phenomenon that occurs specifically in long-span bridges under low wind speed conditions. The generation mechanism of this vibration can be explained from the perspective of fluid mechanics: when the wind flow bypasses the non-streamlined bridge structure, it will form vortices that alternately detach on the windward and leeward sides of the structure. These vortices produce asymmetric pressure distribution on both sides of the bridge, causing vibration of the bridge structure. When the detachment frequency of these vortices generated by the wind flow (also known as vortex shedding frequency) matches a natural vibration frequency of the bridge structure (especially the frequency of the lateral or torsional vibration mode), resonance may be triggered. Resonance can significantly increase the vibration amplitude, leading to structural stress concentration, which may cause fatigue damage or even destruction of the bridge structure. Although the harmfulness of vortex vibration itself may not be high, when the vibration caused by vortex vibration resonates with the natural frequency of the bridge, its potential for structural damage increases significantly, becoming a serious safety hazard. Therefore, in the health monitoring system of cable-stayed bridges, the identification and evaluation of vortex vibration phenomenon is a key link, which requires highly professional technology and comprehensive analysis methods to ensure the long-term safety and reliability of cable-stayed bridges.

[0005] There are certain limitations in the current practice of health monitoring of cable-stayed bridges, especially in terms of the coverage and depth of the monitoring system. Existing monitoring schemes mainly focus on measuring and analyzing the cable forces of individual cable stays, which can provide some key performance indicators but are often insufficient to fully evaluate the comprehensive performance and condition of the entire cable-stayed system. In particular, in terms of the identification and evaluation of vortex-induced vibrations, it is difficult to accurately determine the impact and potential damage that may occur to the overall structure of the bridge by only monitoring the cable forces of individual cables. Summary of the invention

[0006] In order to address the deficiencies of the above-mentioned prior art, the present invention provides a monitoring method and system for a cable-stayed bridge based on cable force and bridge deck acceleration, which realizes performance monitoring and damage risk analysis of the entire cable-stayed system by monitoring three coupling indicators of cable force, cable sag and lateral bridge deck velocity response of a specific cable unit.

[0007] In order to achieve the above-mentioned invention object, the technical solution provided by the present invention includes:

[0008] A cable-stayed bridge monitoring method based on cable force and bridge deck acceleration comprises the following steps:

[0009] Selecting a plurality of pairs of cables on a target cable-stayed bridge as monitoring cables, and obtaining the cable forces and sags of the monitoring cables;

[0010] A section perpendicular to the connection between the bridge deck and the monitoring cable is selected as a monitoring section on the target cable-stayed bridge, and vibration characteristics of the monitoring section are obtained; the vibration characteristics include a transverse acceleration of the monitoring section parallel to the bridge deck and a vertical acceleration perpendicular to the bridge deck;

[0011] Constructing and training a monitoring model based on a supervised neural network; the monitoring model is used to fit the current cable forces of all cables of the target cable-stayed bridge according to the cable forces and sags of each of the monitoring cables to determine whether they exceed the cable bearing capacity limit; the monitoring model is also used to determine whether vortex vibration and resonance occur in the target cable-stayed bridge according to the vibration characteristics of each of the monitoring sections;

[0012] The cable force and sag of each monitoring cable and the vibration characteristics of each monitoring section are input into the trained monitoring model to obtain an assessment result of whether the target cable-stayed bridge has a risk of damage.

[0013] In some preferred embodiments, the method of fitting the current cable forces of all cables of the target cable-stayed bridge according to the cable forces and sags of the monitored cables comprises:

[0014] By mutually checking the cable force and sag of the monitoring cable, the current cable force of the monitoring cable is obtained;

[0015] The current cable forces of other non-monitoring cables of the target cable-stayed bridge are fitted according to the current cable forces of the monitoring cables.

[0016] In some preferred embodiments, the method of fitting the current cable forces of other non-monitoring cables of the target cable-stayed bridge according to the current cable forces of the monitoring cables includes:

[0017] The cable force distribution law of the target cable-stayed bridge is obtained by finite element calculation, and a cable force analysis model of the target cable-stayed bridge is established; the cable force analysis model outputs the predicted cable forces of other cables that have not been input according to the input cable forces of several cables;

[0018] The current cable force of the monitoring cable is input into the cable force analysis model to obtain the current cable forces of other non-monitoring cables of the target cable-stayed bridge.

[0019] In some preferred embodiments, the method for determining whether vortex vibration and resonance occur in the target cable-stayed bridge includes:

[0020] It is determined whether vortex vibration occurs in the target cable-stayed bridge according to the vibration characteristics of each monitoring section; if so, it is determined whether the vortex vibration causes resonance in the target cable-stayed bridge.

[0021] In some preferred embodiments, the method for obtaining the evaluation result of whether the target cable-stayed bridge has a damage risk comprises:

[0022] If vortex vibration occurs in the target cable-stayed bridge and the vortex vibration causes resonance of the target cable-stayed bridge, it is determined whether there is an overlapping interval between the structural natural frequency of the target cable-stayed bridge and the excitation frequency of the vortex vibration. If so, it is determined that there is a risk of damage to the target cable-stayed bridge and an alarm is issued.

[0023] In some preferred embodiments, the method for obtaining the evaluation result of whether the target cable-stayed bridge has a damage risk comprises:

[0024] If vortex vibration or resonance occurs in the target cable-stayed bridge, it is determined whether the current cable forces of all cables of the target cable-stayed bridge exceed the cable bearing capacity limit. If so, it is determined that the target cable-stayed bridge is at risk of damage and an alarm is issued.

[0025] The present invention also provides a cable-stayed bridge monitoring system based on cable force and bridge deck acceleration, comprising:

[0026] A cable force sensor disposed on the monitoring cable is configured to measure the cable fundamental frequency to calculate the cable force; the monitoring cable is a plurality of paired cables on the target cable-stayed bridge; a distance measuring sensor disposed at the mid-span position of the monitoring cable is configured to respectively measure the distance between the mid-span point and the cable tower and the bridge deck to calculate the cable sag;

[0027] The acceleration sensors respectively arranged at both ends of the bridge deck at the monitoring section are configured to obtain the vibration characteristics of the monitoring section, wherein the vibration characteristics include the transverse acceleration of the monitoring section parallel to the bridge deck and the vertical acceleration perpendicular to the bridge deck; the monitoring section is the vertical section at the connection between the bridge deck of the target cable-stayed bridge and the monitoring cable;

[0028] A server is respectively connected to the cable force sensor, the distance sensor and the acceleration sensor signals and has a built-in monitoring model based on a supervised neural network; the monitoring model is configured to fit the current cable force of all cables of the target cable-stayed bridge according to the cable force and sag of each monitoring cable to determine whether it exceeds the cable bearing capacity limit; the monitoring model is also used to determine whether vortex vibration and resonance occur in the target cable-stayed bridge according to the vibration characteristics of each monitoring section; the server is configured to input the cable force and sag of each monitoring cable and the vibration characteristics of each monitoring section into the trained monitoring model to obtain an assessment result of whether the target cable-stayed bridge has a risk of damage;

[0029] The alarm module connected to the server signal is configured to alarm the user according to the evaluation result of the target cable-stayed bridge.

[0030] In some preferred embodiments, the monitoring model includes a cable force fitting unit, which is configured to obtain the current cable force of the monitoring cable by mutual verification of the cable force and sag of the monitoring cable; input the current cable force of the monitoring cable into a cable force analysis model to obtain the current cable force of other non-monitoring cables of the target cable-stayed bridge; the cable force analysis model is established based on the cable force distribution law of the target cable-stayed bridge obtained through finite element calculation.

[0031] In some preferred embodiments, the method for determining whether vortex vibration and resonance occur in the target cable-stayed bridge includes:

[0032] It is determined whether vortex vibration occurs in the target cable-stayed bridge according to the vibration characteristics of each monitoring section; if so, it is determined whether the vortex vibration causes resonance in the target cable-stayed bridge.

[0033] In some preferred embodiments, the method for obtaining the evaluation result of whether the target cable-stayed bridge has a damage risk comprises:

[0034] The server stores the structural natural vibration frequency and cable bearing capacity limit of the target cable-stayed bridge;

[0035] If vortex vibration occurs in the target cable-stayed bridge and the vortex vibration causes resonance of the target cable-stayed bridge, it is determined whether there is an overlap interval between the structural natural frequency of the target cable-stayed bridge and the excitation frequency of the vortex vibration. If so, it is determined that there is a risk of damage to the target cable-stayed bridge, and an alarm is issued to the user through the alarm module;

[0036] If vortex vibration or resonance occurs in the target cable-stayed bridge, it is determined whether the current cable forces of all cables of the target cable-stayed bridge exceed the cable bearing capacity limit. If so, it is determined that there is a risk of damage to the target cable-stayed bridge, and an alarm is issued to the user through the alarm module.

[0037] Beneficial Effects

[0038] The present invention proposes an innovative comprehensive monitoring method for the health monitoring of cable-stayed bridges. By simultaneously monitoring the three key coupling indicators of cable force, cable sag, and bridge deck vibration, a multi-dimensional bridge health assessment framework is constructed, which can not only capture the specific vibration modes caused by vortex vibration and resonance in real time, but also comprehensively consider the impact of these vibrations on the stability of the cable and the entire bridge structure, so as to more accurately assess the damage risk and structural health of the bridge. The present invention has high accuracy and reliability, overcomes the common problems of single monitoring indicators and insufficient data verification in the prior art, reveals the performance of the bridge under normal use and extreme conditions, and provides a more comprehensive and accurate basis for bridge maintenance and emergency response. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1It is a flow chart of a method for monitoring a cable-stayed bridge based on cable force and bridge deck acceleration in a preferred embodiment of the present invention;

[0040] Figure 2 A schematic diagram of the installation position of a monitoring unit on a target cable-stayed bridge in a preferred embodiment of the present invention;

[0041] Figure 3 A schematic diagram of calculating the sag of a cable by a distance measuring sensor in a preferred embodiment of the present invention;

[0042] Figure 4 It is a schematic diagram of the principle of calculating the sag of the cable by a distance measuring sensor in a preferred embodiment of the present invention;

[0043] Figure 5 A schematic diagram of the arrangement of acceleration sensors and the acceleration monitoring direction in the transverse direction of the bridge in a preferred embodiment of the present invention;

[0044] Figure 6 A schematic diagram of the arrangement of acceleration sensors and the longitudinal acceleration monitoring direction in a preferred embodiment of the present invention;

[0045] Figure 7 It is a schematic structural diagram of a cable-stayed bridge monitoring system based on cable force and bridge deck acceleration in another preferred embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described below in conjunction with the accompanying drawings. In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention.

[0047] Example 1

[0048] like Figure 1 As shown, this embodiment provides a cable-stayed bridge monitoring method based on cable force and bridge deck acceleration, comprising the steps of:

[0049] S1. Selecting a number of pairs of cables on the target cable-stayed bridge as monitoring cables, and obtaining the cable forces and sags of the monitoring cables; Figure 2 As shown in the figure, the monitoring unit includes monitoring cables and a monitoring interface. The paired cables refer to the cables on the left and right sides of the target cable-stayed bridge that are mirrored relative to the bridge deck.

[0050] There are many methods for obtaining the cable force. Common methods include directly setting a cable force sensor on the cable. In some preferred embodiments, in order to accurately obtain the cable force, it is considered to set a cable force sensor on the monitoring cable to measure the cable fundamental frequency based on the principle of measuring cable force by vibration method and then calculate the cable force. The core idea of ​​this method is to use the vibration characteristics of the cable to indirectly calculate the cable force, that is, to derive the cable force of the cable by measuring the fundamental frequency of the cable (that is, the main frequency of the natural vibration of the cable). The advantage of this method is that it does not directly rely on the measurement of the cable force by the sensor, thereby reducing the impact of sensor failure or data inaccuracy on the monitoring results. In specific implementation, a special vibration sensor, such as an accelerometer or a strain gauge, can be set on the monitoring cable to capture the vibration response of the cable under natural or external excitation. By analyzing these vibration signals, the fundamental frequency of the cable can be accurately determined. Subsequently, the actual cable force of the cable can be accurately calculated using the relevant theories of vibration and material mechanics, such as the mass, length and vibration mode of the cable.

[0051] The sag refers to the vertical distance between the lowest point of the cable and the fixed points at both ends of the cable under the action of its own weight and other forces (such as wind force, temperature change, additional load, etc.). In some preferred embodiments, a method for obtaining the sag is provided, including:

[0052] A distance measuring sensor is set at the mid-span position of the monitoring cable to measure the distance between the mid-span point and the cable tower and the bridge deck to calculate the cable sag. Figure 3-Figure 4 As shown, the calculation formula is as follows:

[0053] Sag f = (Dh 2 +Dl 2 ) 1 / 2 , where Dh=l1 / L*H-h1; Dl=h1 / H*L-l1.

[0054] S2, selecting a section perpendicular to the connection between the bridge deck and the monitoring cable on the target cable-stayed bridge as a monitoring section, and obtaining vibration characteristics of the monitoring section; Figure 5-Figure 6 As shown in the figure, the vibration characteristics include the transverse acceleration of the monitoring section parallel to the bridge deck and the vertical acceleration perpendicular to the bridge deck; the monitoring of the transverse acceleration (velocity) and the vertical acceleration (velocity) can provide a basis for judging the vibration mode of the bridge deck, and the arrows in the figure indicate the directions of the transverse acceleration (velocity) and the vertical acceleration (velocity).

[0055] S3. Construct and train a monitoring model based on a supervised neural network; the monitoring model is used to fit the current cable tension of all cables of the target cable-stayed bridge according to the cable tension and sag of each monitoring cable to determine whether it exceeds the cable bearing capacity limit; the monitoring model is also used to determine whether vortex vibration and resonance occur in the target cable-stayed bridge according to the vibration characteristics of each monitoring section.

[0056] The supervised neural network is a type of neural network model that is trained with known input-output pairs, and it can learn the mapping relationship between input data and output results. In the application scenario of the present invention, this neural network model can effectively identify and predict the health status of the bridge, including but not limited to key indicators such as bridge deck vibration mode and cable tension changes. The present invention does not specifically limit the supervised neural network model and training method used, which means that the most suitable model and training strategy can be selected according to actual monitoring needs and data characteristics.

[0057] The supervised neural network model used in this invention plays a key role in the health monitoring of cable-stayed bridges. Specifically, it is mainly used for data analysis and processing in two aspects:

[0058] 1. Fitting the coupling relationship between cable force and sag: In the structure of a cable-stayed bridge, there is an inherent coupling relationship between the cable force and sag, that is, the cable force and sag are inversely proportional. This means that an increase in cable force will lead to a decrease in sag, and vice versa. By learning this coupling relationship, the supervised neural network can achieve high-precision prediction of cable force. When the sag information of the cable is obtained through actual measurement, the network can correct the cable force according to the learned coupling relationship, thereby improving the accuracy of cable force monitoring.

[0059] 2. Explore the correlation between cable force, sag and bridge deck acceleration response: In addition to the direct coupling between cable force and sag, there is also a certain correlation between these two parameters and the acceleration response of the bridge deck. This correlation may not be intuitive, but it is crucial for monitoring and assessing the overall health of the bridge. By analyzing various data, the neural network model can reveal these complex relationships and provide more accurate information for bridge condition assessment.

[0060] In some preferred embodiments, an innovative method is proposed for fitting and predicting the current cable forces of other cables that are not directly monitored in a cable-stayed bridge based on the cable force data of the monitored cables. The core of this method is to utilize the mutual verification mechanism between the cable force and sag data of the monitored cables to deduce the cable force of the unmonitored cables. Specifically, it includes:

[0061] The current cable tension of the monitoring cable is obtained by mutual verification of the cable tension and sag of the monitoring cable; the current cable tension of other non-monitoring cables of the target cable-stayed bridge is fitted according to the current cable tension of the monitoring cable. The advantage of this method is that it can indirectly evaluate the cable tension status of the entire cable-stayed bridge without directly installing monitoring equipment on each cable, which not only reduces the monitoring cost but also improves the efficiency of maintenance and management of cable-stayed bridges. It should be emphasized that although the present invention provides this basic idea, the specific verification method and cable tension fitting algorithm can be flexibly selected according to the characteristics and requirements of the actual bridge, and the present invention does not limit the specific forms of these methods and algorithms.

[0062] The fitting can be obtained by establishing a fitting model or calculating according to an empirical formula. In other preferred embodiments, a method for obtaining the current cable force of a non-monitoring cable by finite element calculation is provided, which specifically includes:

[0063] The cable force distribution law of the target cable-stayed bridge is obtained by finite element calculation, and a cable force analysis model of the target cable-stayed bridge is established. The model can simulate and analyze the physical behavior and structural response of the cable-stayed bridge. Finite element analysis is a powerful calculation tool widely used in engineering and physical sciences. By dividing complex structures into smaller, simple-shaped elements, the structural response under various loading conditions can be accurately predicted; the cable force analysis model outputs the predicted cable forces of other cables that have not been input according to the input cable forces of several cables; it should be understood that the finite element calculation of the present invention can be based on the finite element model or finite element software commonly used in the field, and the specific analysis model and calculation process can be adjusted and optimized according to the characteristics and requirements of the actual bridge. Obviously, the cable force analysis model provides a method for predicting the cable forces of other cables based on the changes in partial cable forces. The current cable force of the monitoring cable is input into the cable force analysis model to obtain the current cable forces of other non-monitoring cables of the target cable-stayed bridge.

[0064] S4. Input the cable force and sag of each monitoring cable and the vibration characteristics of each monitoring section into the trained monitoring model to obtain an assessment result of whether the target cable-stayed bridge has a risk of damage. The monitoring model is trained by using a large amount of cable force, sag and vibration characteristic data and relevant data between the cable-stayed bridge status as a training set, focusing on the correlation between the monitoring model's vibration characteristics and vortex vibration and resonance. Among them, as described in the background technology, the degree of harmfulness of vortex vibration itself may not be high, but when the vibration caused by vortex vibration resonates with the natural frequency of the bridge, its destructive potential to the structure increases significantly, becoming a serious safety hazard. Therefore, in some preferred embodiments, consider using the following method to determine whether vortex vibration and resonance occur in the target cable-stayed bridge:

[0065] According to the vibration characteristics of each of the monitoring sections, it is determined whether the target cable-stayed bridge has vortex vibration; if so, it is determined whether the vortex vibration causes the target cable-stayed bridge to resonate. When the target cable-stayed bridge has vortex vibration and resonance at the same time, it is considered that the target cable-stayed bridge is at a greater risk of damage. In some preferred embodiments, a method for further determination to obtain an evaluation result of whether the target cable-stayed bridge has a risk of damage is provided:

[0066] If vortex vibration occurs in the target cable-stayed bridge and the vortex vibration causes resonance of the target cable-stayed bridge, it is determined whether there is an overlapping interval between the structural natural frequency of the target cable-stayed bridge and the excitation frequency of the vortex vibration. If so, it is determined that there is a risk of damage to the target cable-stayed bridge and an alarm is issued.

[0067] In addition to considering the hidden dangers of vibration characteristics, some preferred embodiments also consider the actual state of the cables in the cable-stayed system. That is, if vortex vibration or resonance occurs in the target cable-stayed bridge, it is determined whether the current cable tension of all cables of the target cable-stayed bridge exceeds the cable bearing capacity limit. If so, it is determined that the target cable-stayed bridge is at risk of damage and an alarm is issued.

[0068] Example 2

[0069] like Figure 7 As shown, this embodiment provides a cable-stayed bridge monitoring system based on cable force and bridge deck acceleration, including:

[0070] A cable force sensor disposed on the monitoring cable is configured to measure the cable fundamental frequency to calculate the cable force; the monitoring cable is a plurality of paired cables on the target cable-stayed bridge; a distance measuring sensor disposed at the mid-span position of the monitoring cable is configured to respectively measure the distance between the mid-span point and the cable tower and the bridge deck to calculate the cable sag;

[0071] The acceleration sensors respectively arranged at both ends of the bridge deck at the monitoring section are configured to obtain the vibration characteristics of the monitoring section, wherein the vibration characteristics include the transverse acceleration of the monitoring section parallel to the bridge deck and the vertical acceleration perpendicular to the bridge deck; the monitoring section is the vertical section at the connection between the bridge deck of the target cable-stayed bridge and the monitoring cable;

[0072] A server is respectively connected to the cable force sensor, the distance sensor and the acceleration sensor signals and has a built-in monitoring model based on a supervised neural network; the monitoring model is configured to fit the current cable force of all cables of the target cable-stayed bridge according to the cable force and sag of each monitoring cable to determine whether it exceeds the cable bearing capacity limit; the monitoring model is also used to determine whether vortex vibration and resonance occur in the target cable-stayed bridge according to the vibration characteristics of each monitoring section; the server is configured to input the cable force and sag of each monitoring cable and the vibration characteristics of each monitoring section into the trained monitoring model to obtain an assessment result of whether the target cable-stayed bridge has a risk of damage;

[0073] The alarm module connected to the server signal is configured to alarm the user according to the evaluation result of the target cable-stayed bridge.

[0074] In some preferred embodiments, the monitoring model includes a cable force fitting unit, which is configured to obtain the current cable force of the monitoring cable by mutual verification of the cable force and sag of the monitoring cable; input the current cable force of the monitoring cable into a cable force analysis model to obtain the current cable force of other non-monitoring cables of the target cable-stayed bridge; the cable force analysis model is established based on the cable force distribution law of the target cable-stayed bridge obtained through finite element calculation.

[0075] In some preferred embodiments, the method for determining whether vortex vibration and resonance occur in the target cable-stayed bridge includes:

[0076] It is determined whether vortex vibration occurs in the target cable-stayed bridge according to the vibration characteristics of each monitoring section; if so, it is determined whether the vortex vibration causes resonance in the target cable-stayed bridge.

[0077] In some preferred embodiments, the method for obtaining the evaluation result of whether the target cable-stayed bridge has a damage risk comprises:

[0078] The server stores the structural natural vibration frequency and cable bearing capacity limit of the target cable-stayed bridge;

[0079] If vortex vibration occurs in the target cable-stayed bridge and the vortex vibration causes resonance of the target cable-stayed bridge, it is determined whether there is an overlap interval between the structural natural frequency of the target cable-stayed bridge and the excitation frequency of the vortex vibration. If so, it is determined that there is a risk of damage to the target cable-stayed bridge, and an alarm is issued to the user through the alarm module;

[0080] If vortex vibration or resonance occurs in the target cable-stayed bridge, it is determined whether the current cable forces of all cables of the target cable-stayed bridge exceed the cable bearing capacity limit. If so, it is determined that there is a risk of damage to the target cable-stayed bridge, and an alarm is issued to the user through the alarm module.

[0081] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A cable-stayed bridge monitoring method based on cable force and bridge deck acceleration, characterized in that: Includes steps: Selecting a plurality of pairs of cables on a target cable-stayed bridge as monitoring cables, and obtaining the cable forces and sags of the monitoring cables; A section perpendicular to the connection between the bridge deck and the monitoring cable is selected as a monitoring section on the target cable-stayed bridge, and vibration characteristics of the monitoring section are obtained; the vibration characteristics include a transverse acceleration of the monitoring section parallel to the bridge deck and a vertical acceleration perpendicular to the bridge deck; Constructing and training a monitoring model based on a supervised neural network; the monitoring model is used to fit the current cable forces of all cables of the target cable-stayed bridge according to the cable forces and sags of each of the monitoring cables to determine whether they exceed the cable bearing capacity limit; the monitoring model is also used to determine whether vortex vibration and resonance occur in the target cable-stayed bridge according to the vibration characteristics of each of the monitoring sections; Inputting the cable force and sag of each monitoring cable and the vibration characteristics of each monitoring section into the trained monitoring model to obtain an assessment result of whether the target cable-stayed bridge has a risk of damage; The method for determining whether vortex vibration and resonance occur in a target cable-stayed bridge comprises: Determine whether vortex vibration occurs in the target cable-stayed bridge according to the vibration characteristics of each monitoring section; if so, determine whether the vortex vibration causes resonance in the target cable-stayed bridge; The method for obtaining an evaluation result of whether the target cable-stayed bridge has a damage risk comprises: If vortex vibration occurs in the target cable-stayed bridge and the vortex vibration causes resonance of the target cable-stayed bridge, it is determined whether there is an overlapping interval between the structural natural frequency of the target cable-stayed bridge and the excitation frequency of the vortex vibration. If so, it is determined that there is a risk of damage to the target cable-stayed bridge and an alarm is issued.

2. The cable-stayed bridge monitoring method based on cable force and bridge deck acceleration according to claim 1, characterized in that: The method for fitting the current cable forces of all cables of the target cable-stayed bridge according to the cable forces and sags of the monitoring cables comprises: By mutually checking the cable force and sag of the monitoring cable, the current cable force of the monitoring cable is obtained; The current cable forces of other non-monitoring cables of the target cable-stayed bridge are fitted according to the current cable forces of the monitoring cables.

3. The cable-stayed bridge monitoring method based on cable force and bridge deck acceleration according to claim 2, characterized in that: The method for fitting the current cable forces of other non-monitoring cables of the target cable-stayed bridge according to the current cable forces of the monitoring cables comprises: The cable force distribution law of the target cable-stayed bridge is obtained by finite element calculation, and a cable force analysis model of the target cable-stayed bridge is established; the cable force analysis model outputs the predicted cable forces of other cables that have not been input according to the input cable forces of several cables; The current cable force of the monitoring cable is input into the cable force analysis model to obtain the current cable forces of other non-monitoring cables of the target cable-stayed bridge.

4. The cable-stayed bridge monitoring method based on cable force and bridge deck acceleration according to claim 1, characterized in that: The method for obtaining an evaluation result of whether the target cable-stayed bridge has a damage risk comprises: If vortex vibration or resonance occurs in the target cable-stayed bridge, it is determined whether the current cable forces of all cables of the target cable-stayed bridge exceed the cable bearing capacity limit. If so, it is determined that the target cable-stayed bridge is at risk of damage and an alarm is issued.

5. A cable-stayed bridge monitoring system based on cable force and bridge deck acceleration, characterized in that: include: A cable force sensor disposed on the monitoring cable, configured to measure the cable fundamental frequency to calculate the cable force; The monitoring cables are a plurality of paired cables on the target cable-stayed bridge; A distance measuring sensor disposed at the mid-span position of the monitoring cable, configured to measure the distance between the mid-span point and the cable tower and the bridge deck respectively to calculate the cable sag; The acceleration sensors respectively arranged at both ends of the bridge deck at the monitoring section are configured to obtain the vibration characteristics of the monitoring section, wherein the vibration characteristics include the transverse acceleration of the monitoring section parallel to the bridge deck and the vertical acceleration perpendicular to the bridge deck; the monitoring section is the vertical section at the connection between the bridge deck of the target cable-stayed bridge and the monitoring cable; A server is respectively connected to the cable force sensor, the distance sensor and the acceleration sensor signals and has a built-in monitoring model based on a supervised neural network; the monitoring model is configured to fit the current cable force of all cables of the target cable-stayed bridge according to the cable force and sag of each monitoring cable to determine whether it exceeds the cable bearing capacity limit; the monitoring model is also used to determine whether vortex vibration and resonance occur in the target cable-stayed bridge according to the vibration characteristics of each monitoring section; the server is configured to input the cable force and sag of each monitoring cable and the vibration characteristics of each monitoring section into the trained monitoring model to obtain an assessment result of whether the target cable-stayed bridge has a risk of damage; An alarm module connected to the server signal, configured to alarm a user according to the evaluation result of the target cable-stayed bridge; The method for determining whether vortex vibration and resonance occur in a target cable-stayed bridge comprises: Determine whether vortex vibration occurs in the target cable-stayed bridge according to the vibration characteristics of each monitoring section; if so, determine whether the vortex vibration causes resonance in the target cable-stayed bridge; The method for obtaining an evaluation result of whether the target cable-stayed bridge has a damage risk comprises: The server stores the structural natural vibration frequency and cable bearing capacity limit of the target cable-stayed bridge; If vortex vibration occurs in the target cable-stayed bridge and the vortex vibration causes resonance of the target cable-stayed bridge, it is determined whether there is an overlap interval between the structural natural frequency of the target cable-stayed bridge and the excitation frequency of the vortex vibration. If so, it is determined that there is a risk of damage to the target cable-stayed bridge, and an alarm is issued to the user through the alarm module; If vortex vibration or resonance occurs in the target cable-stayed bridge, it is determined whether the current cable forces of all cables of the target cable-stayed bridge exceed the cable bearing capacity limit. If so, it is determined that there is a risk of damage to the target cable-stayed bridge, and an alarm is issued to the user through the alarm module.

6. The cable-stayed bridge monitoring system based on cable force and bridge deck acceleration according to claim 5, characterized in that: The monitoring model includes a cable force fitting unit configured to obtain the current cable force of the monitoring cable by mutually checking the cable force and sag of the monitoring cable; Inputting the current cable force of the monitoring cable into the cable force analysis model to obtain the current cable forces of other non-monitoring cables of the target cable-stayed bridge; The cable force analysis model is established based on the cable force distribution law of the target cable-stayed bridge obtained through finite element calculation.

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