Closing monitoring method of cable-stayed bridge and related equipment

Abstract

The invention discloses a closure monitoring method of a cable-stayed bridge and related equipment, and relates to the technical field of bridge construction, and the method comprises the steps: carrying out the stress analysis of a bridge closure stage based on a mechanical model of a bridge, and obtaining the initial stress distribution; based on the initial stress distribution, regulating and controlling a pre-stress distribution strategy in a bridge closure stage to obtain optimized pre-stress distribution; adjusting the mechanical state of a closure point based on the prestress distribution; and determining the stability of the bridge closure stage based on the mechanical state. According to the method, optimization of stress distribution and dynamic monitoring of structural stability can be achieved in the closure process of the cable-stayed bridge, structural instability and local damage are effectively prevented, and the safety and reliability of bridge construction are improved.

Description

Technical Field

[0001] The present application relates to the technical field of bridge construction, and in particular to a closure monitoring method and related equipment for a cable-stayed bridge. Background Art

[0002] The closure of a cable-stayed bridge is a critical stage in bridge construction, which refers to the merging of the steel trusses or cables at both ends of the bridge to complete the connection of the bridge. If stress concentration or structural force imbalance occurs during the closure process, it may cause local damage, uneven deformation or structural instability, thus affecting the overall safety and service life of the bridge.

[0003] At present, the mechanical monitoring and control of the closure process of cable-stayed bridges mainly rely on static analysis and conventional monitoring equipment. These methods are difficult to fully capture the dynamic changes in the closure process, especially in the case of complex stress distribution and local instability, and cannot be adjusted and optimized in time. Therefore, a closure monitoring method for cable-stayed bridges is urgently needed to solve the above problems. Summary of the invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description of the Invention section. The Summary of the Invention section of this application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0005] In a first aspect, the present application provides a closure monitoring method for a cable-stayed bridge, comprising:

[0006] Based on the mechanical model of the bridge, stress analysis is performed on the bridge closure stage to obtain the initial stress distribution;

[0007] Based on the initial stress distribution, the prestress distribution strategy during the bridge closure stage is adjusted to obtain the optimized prestress distribution;

[0008] Adjust the mechanical state of the joint point based on the prestress distribution;

[0009] Based on the mechanical state, the stability of the bridge at the closure stage is determined.

[0010] In some embodiments, the mechanical model is determined based on the following formula, expressed as:

[0011]

[0012] Among them, w(x, t) is the displacement of the steel truss at the position x at the joint point; M(x, t) is the bending moment at the position x; E is the elastic modulus of the steel; I is the section moment of inertia of the steel truss; x is the horizontal position coordinate of the steel truss; t is the time variable of the joint stage.

[0013] In some embodiments, based on the initial stress distribution, the prestress distribution strategy at the bridge closure stage is regulated to obtain an optimized prestress distribution, including:

[0014] Based on the initial stress distribution, the current stress distribution quality is calculated through the objective function;

[0015] Based on the quality of stress distribution, the gradient of the objective function with respect to the prestress distribution coefficient is calculated;

[0016] Based on the gradient, the prestress distribution coefficient is updated by the gradient descent method;

[0017] Until the minimum value of the objective function is reached, the optimized prestress distribution is obtained.

[0018] In some embodiments, the objective function is determined based on the following formula, expressed as:

[0019]

[0020] Among them, P i is the prestress of the i-th cable; σ i is the standard stress of cable i; λ is the regularization factor; dF / dx is the force change rate during the closure process; P is the vector of all prestressing forces; L is the length of the steel truss; N is the number of cables.

[0021] In some embodiments, adjusting the mechanical state of the closure point based on the prestress distribution includes:

[0022] Based on the prestress distribution, determine the mechanical state at the current moment;

[0023] Based on the mechanical state, for each time step, the mechanical state at the next moment is calculated according to a recursive formula to optimize the mechanical behavior of the bridge during the closure process, wherein the recursive formula is determined based on a feedback function.

[0024] In some embodiments, the feedback function is determined based on the following formula, expressed as:

[0025]

[0026] Among them, f(P(t), u(t)) is the feedback function; P(t) is the prestress of the joint point at the tth moment; u(t) is the displacement vector at the current moment; is the objective function Gradient of prestress at the joint point; α is a constant coefficient; du(t) / dt is the time derivative of displacement; β is the damping coefficient.

[0027] In some embodiments, determining the stability of the bridge at the closure stage based on the mechanical state includes:

[0028] Based on the mechanical state, calculate the stability index;

[0029] Based on the stability index, the instability mode analysis of the bridge at the closure stage was carried out and the analysis results were obtained;

[0030] Based on the analysis results, the stability of the bridge at the closure stage is determined.

[0031] In a second aspect, the present application proposes a closure monitoring device for a cable-stayed bridge, comprising:

[0032] The stress distribution acquisition unit is used to perform stress analysis on the bridge closure stage based on the mechanical model of the bridge and obtain the initial stress distribution;

[0033] The prestress distribution optimization unit is used to adjust the prestress distribution strategy at the bridge closure stage based on the initial stress distribution to obtain the optimized prestress distribution;

[0034] A mechanical state adjustment unit, used to adjust the mechanical state of the closure point based on the prestress distribution;

[0035] The bridge stability judgment unit is used to determine the stability of the bridge at the closure stage based on the mechanical state.

[0036] In a third aspect, an electronic device comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor is configured to implement the steps of the cable-stayed bridge closure monitoring method of any one of the first aspects when executing the computer program stored in the memory.

[0037] In a fourth aspect, the present application further proposes a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for monitoring the closure of a cable-stayed bridge of any one of the first aspects is implemented.

[0038] In summary, the present application provides a cable-stayed bridge closure monitoring method based on bridge mechanical modeling and optimization algorithm. By accurately calculating and regulating the mechanical state of the closure stage, the stability monitoring and prestress optimization of the bridge during the closure process are realized. This method establishes a force model of the steel truss, dynamically adjusts the prestress distribution, and uses optimization algorithms such as gradient descent to ensure that the mechanical state of the closure point is in the best state, effectively avoiding problems such as local instability, excessive deformation and stress concentration. Combining the recursive algorithm with the stability analysis of the variational principle, the mechanical state during the closure process is monitored in real time, and the prestress and displacement are dynamically adjusted according to the stability index to ensure the structural stability of the bridge, thereby improving the safety, accuracy and reliability of bridge construction. Compared with traditional methods, this technology provides more accurate theoretical support and technical guarantee for the construction of large-span cable-stayed bridges, significantly improves the quality and efficiency of bridge construction, and has broad application prospects and significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present specification. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0040] Figure 1 A schematic flow chart of a closure monitoring method for a cable-stayed bridge provided in an embodiment of the present application;

[0041] Figure 2 A schematic structural diagram of a closure monitoring device for a cable-stayed bridge provided in an embodiment of the present application;

[0042] Figure 3 A schematic diagram of the structure of an electronic device for monitoring the closure of a cable-stayed bridge provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0044] See also Figure 1 , which is a schematic flow chart of a method for controlling inclusions in molten steel provided in an embodiment of the present application, and may specifically include:

[0045] S110, based on the mechanical model of the bridge, perform stress analysis on the bridge closure stage to obtain initial stress distribution;

[0046] For example, during the bridge closure stage, the initial stress distribution of the bridge closure point and its surrounding areas needs to be obtained. In order to achieve this goal, it is necessary to establish a force model based on steel trusses, which can reflect the force and deformation behavior of the bridge during the closure process. The steel trusses undergo bending deformation during the closure process, so the bending deformation model is used to describe its force behavior. By solving the relevant differential equations, the displacement and bending moment distribution of each position of the steel trusses during the closure process can be obtained. The differential equation contains parameters such as the elastic modulus and section inertia moment of the steel trusses, reflects the bending resistance of the steel trusses, and takes into account the mechanical state that changes with time, thereby providing basic data for subsequent stress analysis. During the closure process, the steel trusses are not only subjected to the external load, but also to the transmission of forces at the inclined cables and the closure point. These factors will cause significant changes in stress and deformation near the closure point. Therefore, the equation is solved by numerical methods (such as finite element method or difference method) to obtain the stress distribution at each stage of the closure.

[0047] In order to more accurately describe the local mechanical behavior near the closure point, it is also necessary to introduce the local stiffness coefficient. The local stiffness coefficient is used to reflect the mechanical response of the steel truss near the closure point, especially the effect of the interaction between the cable and the steel truss on the stress distribution. The introduction of the local stiffness coefficient can effectively describe the force transmission and deformation concentration during the closure process, so that the mechanical state at the closure point can be more accurately reflected. The stress distribution in this process is not only related to the overall stress state of the steel truss, but also affected by the external load and force transmission during the closure process. Therefore, by solving the model, the initial stress distribution can be obtained, which provides a theoretical basis for the prestress adjustment and structural optimization in the subsequent closure process. This analysis provides scientific data support to ensure the safety and stability of the bridge closure process.

[0048] The forces on the steel truss can be described by bending moment, shear force, axial force, etc. The bending moment and displacement of the steel truss during the closure process are calculated. The bending deformation of the steel truss can be expressed by the following differential equation:

[0049]

[0050] Among them, w(x, t) is the displacement of the steel truss at the joint point at position x, which describes the displacement of each point during the joint process; M(x, t) is the bending moment at position x, which reflects the bending effect of external force on the steel truss; E is the elastic modulus of steel, which reflects the resistance of steel to deformation; I is the section moment of inertia of the steel truss, which describes the size of the structural bending resistance; x is the horizontal position coordinate of the steel truss; t is the time variable in the closure process, which is used to describe the closure state that changes with time.

[0051] This equation is solved using numerical methods (such as the finite element method or the difference method) to obtain the displacement w(x, t) and bending moment distribution M(x, t) of each position of the steel truss at each moment.

[0052] During the closure process, the steel truss will not only experience bending deformation, but also be affected by the transmission of forces from the inclined cables and the closure point. These effects will cause significant changes in stress and deformation near the closure point. Therefore, the local mechanical behavior of the closure point needs to be considered. In order to better understand these effects, a local stiffness coefficient k(x) is introduced. This coefficient reflects the stiffness of the steel truss in the local area and represents the mechanical response near the closure point. The mechanical behavior of the closure point is expressed by the following formula:

[0053] F(x,t)=∫ 0 (k(x)·Δx)dx

[0054] Among them, F(x, t) is the total force at the joint point, which is the force exerted on the steel truss by the cable or other external forces; k(x) is the local stiffness, which represents the interaction between the steel truss and the cable, and represents the strength of the interaction between the steel truss and the cable during the joint process; Δx is the deformation of the steel truss, which represents the displacement at this position; L is the length of the steel truss.

[0055] Calculate the stress distribution during the closure process, expressed as:

[0056]

[0057] Among them, σ(x, t) is the stress at position x, which represents the tensile or compressive stress on the bridge at that point; σ(x, t) is the distance from the joint centerline to the joint point, which represents the offset of different points on the beam section.

[0058] S120, based on the initial stress distribution, adjusting the prestress distribution strategy at the bridge closure stage to obtain an optimized prestress distribution;

[0059] Exemplarily, during the closure process of a cable-stayed bridge, the initial stress distribution is obtained through the mechanical model established in step S110, which reflects the stress state of the closure point of the bridge and its surrounding areas under the current prestress and external load conditions. In order to ensure the stability of the closure process and the safety of the structure, it is necessary to optimize the prestress distribution strategy to achieve uniform stress distribution and avoid stress concentration. Based on the initial stress distribution, the core of optimizing the prestress distribution strategy is to adjust the prestress coefficient of each cable through a mathematical optimization algorithm, thereby minimizing the unevenness and concentration of stress distribution.

[0060] Define an objective function This function is used to evaluate the quality of stress distribution under the current prestress distribution. The objective function is usually designed as the sum of stress values ​​in the stress concentration area or the variance of stress distribution to quantify the uniformity of stress distribution. Based on the initial stress distribution, the value of the objective function is calculated by numerical method to reflect the stress state under the current prestress distribution strategy. The objective function It is expressed as:

[0061]

[0062] Among them, P i is the prestress of the i-th cable; σ i is the standard stress of cable i, indicating the maximum bearing capacity of each cable; λ is the regularization factor, which is used to balance the stress and force distribution terms in the objective function; dF / dx is the force change rate during the closure process; P is the vector of all prestresses; N is the number of cables.

[0063] The core of this optimization process is to adjust the total stress distribution at the joint point by adjusting the prestress of the cables. The goal is to minimize the generation of uneven stress during the joint and optimize the tension of each cable.

[0064] The prestress adjustment formula of the joint point is expressed as:

[0065]

[0066] Where P(t) is the total prestress at the closure point, which represents the mechanical influence of the comprehensive prestress of each cable on the closure point; α i is the prestress distribution coefficient of each cable, which will affect the tension of each cable; F i (t) is the force acting on each cable;

[0067] The prestress adjustment formula allows for flexible distribution of prestress among multiple cables, ensuring uniform stress distribution and overall stability of the structure. When the stress of a cable is too high, the tension of the cable can be reduced by reducing its prestress distribution coefficient, and vice versa. In this way, the formula not only achieves dynamic optimization of stress distribution, but also effectively avoids the risk of local instability caused by overload of a single cable. By combining this formula with the optimization algorithm, the prestress distribution can be adjusted in real time during the closure process, ensuring that the cable-stayed bridge structure maintains the best mechanical state and stability throughout the closure stage.

[0068] Based on the initial stress distribution, the value of the objective function is calculated by numerical method to reflect the stress state under the current prestress distribution strategy. The gradient of the objective function relative to each prestress distribution coefficient is calculated, that is, the sensitivity of the objective function to the prestress of each cable. This reflects the direction and degree of influence of the change of the prestress distribution coefficient on the quality of stress distribution. Subsequently, the prestress distribution coefficient is updated by the gradient descent method to gradually optimize the stress distribution. According to the calculated gradient, each prestress distribution coefficient is adjusted according to the preset learning rate to gradually reduce the objective function value.

[0069] By continuously iterating this process, the prestress distribution coefficient is adjusted until the objective function reaches the minimum value, indicating that the stress distribution has been optimized to the most uniform state. The optimized prestress distribution strategy will effectively reduce stress concentration and unevenness during the closure process and improve the overall stability and safety of the bridge structure.

[0070] S130, adjusting the mechanical state of the closure point based on the prestress distribution;

[0071] For example, during the closure of a cable-stayed bridge, the optimization of prestress distribution is a key step to ensure the stability and safety of the bridge structure. Based on the optimized prestress distribution strategy, the mechanical state of the closure point needs to be dynamically adjusted to adapt to the force changes and structural response during the closure process. This adjustment process includes the following aspects:

[0072] First, the optimized prestress distribution coefficient αi is used to recalculate the prestress P(t) of each cable at the closure point. The adjustment of prestress directly affects the stress state of the closure point. The reasonable distribution of prestress can effectively reduce stress concentration and balance the stress of various parts of the bridge. According to the recursive formula:

[0073] P(t+1)=P(t)+Δt·f(P(t),u(t))

[0074] Among them, P(t) is the prestress of the closure point at the tth moment, which represents the total prestress of the cable at the current moment; P(t+1) is the prestress of the closure point at the t+1th moment, which is the prestress obtained by recursive calculation; Δt is the time step, which represents the time interval of each recursive step; f(P(t), u(t)) is the feedback function, which represents the mechanical behavior of the closure point and describes the influence of the current prestress and displacement on the state of the closure point; u(t) is the displacement vector at the current moment, which represents the displacement state of the steel truss during the closure process.

[0075] The feedback function is expressed as follows according to the nonlinear behavior of the structure:

[0076]

[0077] in, is the objective function The gradient of the prestress P at the closure point reflects the mechanical behavior of the closure point and the influence of the prestress on the structural state. α is a constant coefficient, which is used to adjust the contribution of the gradient term to the recursion; du(t) / dt is the time derivative of the displacement, which indicates the rate of change of the displacement with time during the closure process, reflecting the speed of structural deformation. The progress of the closure process is adjusted by the displacement change to avoid local instability caused by excessive deformation; β is the damping coefficient, which is used to adjust the influence of the displacement change on the recursion process.

[0078] Based on the numerical integration method (such as Euler method or Runge-Kutta method), the time derivative of the joint point displacement u(t+1) is calculated and the displacement value is updated, which is expressed as:

[0079]

[0080] The update of displacement reflects the structural deformation during the closure process. By accurately controlling the displacement change, local instability or uneven structural stress caused by excessive deformation can be avoided. The numerical integration method ensures that the displacement calculation process is stable and highly accurate, so that each step of the mechanical state adjustment during the closure process can accurately reflect the actual structural response.

[0081] Finally, through the dynamic adjustment of the prestress and displacement mentioned above, the mechanical state of the closure point can be optimized in real time. Each adjustment is based on the latest mechanical state feedback, forming a closed-loop control system to ensure that the structure is always in the best stress state during the closure process. In this way, it can not only effectively prevent stress concentration and local instability, but also improve the bearing capacity and durability of the entire bridge structure, ensuring that the cable-stayed bridge maintains a high degree of safety and stability during the closure stage and subsequent use.

[0082] In the embodiment of the present application, during the closure process, the force and displacement of the closure point should be finely controlled through multi-step recursion to avoid structural instability caused by instantaneous large forces. Through the recursive algorithm, the closure progress of each stage can be gradually optimized to avoid local structural instability caused by the rapid change of force during the closure process. The recursive method is used to dynamically adjust the mechanical state at each moment to ensure the smooth progress of the closure process, and the prestress and displacement of the next step are predicted and adjusted based on the output of the previous step.

[0083] S140. Determine the stability of the bridge at the closure stage based on the mechanical state.

[0084] For example, during the closure of a bridge, prestressing maintains the stability of the structure by applying tension to the cables. Prestressing, as an initial stress of the structure, mainly comes from the loading of the cables or support systems. By applying prestressing, the stress state of the structure can be effectively changed, the deformation under the action of external forces can be reduced, and the overall stability of the structure can be enhanced. Specifically, the adjustment of prestressing is carried out step by step through a recursive algorithm to ensure that there will be no excessive local stress concentration or excessive deformation during the closure process, thereby avoiding structural instability. This process not only optimizes the stress distribution, but also ensures that the mechanical behavior of the bridge during the closure stage is always in a controlled and stable state.

[0085] The resultant force is the sum of all the forces applied to the joint point in the entire structural system, reflecting the stress state of the structure during the joint process. The resultant force not only includes the influence of prestress, but also covers the reaction force, load and other external forces of each component of the bridge. The resultant force directly affects the displacement, deformation and stress distribution of the structure, and its magnitude and direction are usually determined by the distribution of prestress and the stiffness of the bridge structure. When the prestress applied by the cable increases, the resultant force also increases, so the structure becomes more taut and can better resist external forces; conversely, insufficient prestress may cause the structure to deform significantly during the joint, and the resultant force is insufficient to support the stability of the structure.

[0086] The variational principle model provides a theoretical analysis framework for determining whether a structure will become unstable. Through virtual work and variation, it is possible to evaluate whether the interaction between the resultant force and the displacement is in a critical state of instability. When the structure is subjected to stress, the virtual displacement and the work of the virtual force of the system are equal to zero, expressed as:

[0087] δW=∫ 0 (F(t+1) T u(t+1)-δF(t+1) T δu(t+1))dx

[0088] Among them, F(t+1) is the resultant force after closure, which represents all external forces acting at the closure point, including prestress; u(t+1) is the displacement after closure, which is the deformation of the structure under the action of force; δF(t+1) is the virtual force; δu(t+1) is the virtual displacement; and δW is the virtual work.

[0089] The stability index S is a quantitative index derived from the variational principle model. It is used to measure the stability of the current structure during the closure process. It is calculated based on the current mechanical state. The mechanical state is determined by the prestress P(t) and the displacement u(t). The stability index S quantitatively evaluates whether the bridge structure is close to the critical point of instability by measuring the relationship between the resultant force and the displacement. The stability index S is expressed as:

[0090]

[0091] Among them, S is the stability index; F(t+1) is the resultant force vector at the next moment; u(t+1) is the displacement vector at the next moment; F(t+1) T u(t+1) is the inner product of the resultant force and the displacement; ||F(t+1)|| is the norm of the resultant force; ||u(t+1)|| is the norm of the displacement.

[0092] The value of the index S reflects the stability level of the structure under the current mechanical state: when the S value is greater than or equal to the first threshold, it means that the structure has a high stability; conversely, if the S value is less than the first threshold, it indicates that the structure is close to instability and requires further analysis and adjustment.

[0093] Based on the calculation results of the stability index S, the instability mode analysis is mainly achieved through the eigenvalue analysis method. Eigenvalue analysis is a commonly used mechanical analysis technique used to determine the dynamic response characteristics of the structure under the current prestress and displacement conditions. Through eigenvalue analysis, the eigenfrequency and eigenmode of the structure can be identified. This information can reveal the possible instability behavior of the structure under specific load and deformation conditions. For example, the eigenvalue of a certain instability mode is close to zero, which means that the structural deformation corresponding to this mode is prone to occur, and the structure may experience local buckling or overall instability in this mode. This analysis helps to identify weak links and potential instability risks in the structure in advance, ensuring that targeted preventive measures can be taken during the closure process.

[0094] When the results of the instability mode analysis show that the eigenvalue of a certain mode is close to zero, it is necessary to adjust the prestress distribution and displacement control strategy according to the specific instability mode results. For example, if a local area is subjected to stress concentration due to uneven prestress distribution, it may cause local buckling in the area. At this time, the prestress of the inclined cable can be redistributed to increase or decrease the tension of a specific cable to optimize the stress distribution and avoid excessive stress concentration. In addition, the bending resistance of the area can be improved to prevent local instability by enhancing local stiffness, such as increasing the cross-sectional size of the steel truss or adding support points. Through these adjustment measures, the stress distribution during the bridge closure process can be effectively optimized, ensuring that the entire structure maintains good stability during the closure stage, preventing structural instability caused by excessive stress concentration or rapid deformation, and improving the safety and reliability of bridge construction.

[0095] Through the above steps, the monitoring of mechanical state and stability evaluation form a closed-loop control system. Stability index S It provides a quantitative method for quickly evaluating structural stability, while the instability mode analysis deeply reveals the potential causes and modes of instability. Combining the analysis results of the two, the prestress and displacement during the closure process can be dynamically adjusted to ensure that the cable-stayed bridge always maintains good mechanical stability during the closure process, prevent structural instability and local damage, and improve the safety and reliability of bridge construction.

[0096] In summary, this application firstly performs stress analysis on the bridge closure stage based on the mechanical model of the bridge to obtain the initial stress distribution; by establishing an accurate mechanical model and using numerical methods, it is possible to describe in detail the stress and deformation of each part of the bridge during the closure process, especially the stress concentration phenomenon near the closure point. Then, based on the initial stress distribution, the prestress distribution strategy of the bridge closure stage is regulated to obtain the optimized prestress distribution; the prestress distribution coefficient of each inclined cable is adjusted by using the objective function and optimization algorithm, aiming to uniformly distribute stress, avoid stress concentration and local overload, and thus improve the overall stability of the structure. Then, based on the prestress distribution, the mechanical state of the closure point is adjusted; the prestress and displacement are dynamically adjusted by the recursive algorithm to ensure that the mechanical state at each moment during the closure process remains within the controlled range; this process optimizes the prestress distribution and displacement control in real time through a closed-loop feedback mechanism to prevent structural instability caused by excessive deformation or stress concentration. Finally, based on the mechanical state, the stability of the bridge closure stage is determined; the stability index is calculated and the instability mode analysis is performed to evaluate the stability level of the current structure. When the indicators show that the structure is close to the critical point of instability, the prestress distribution and displacement control strategy are further adjusted to ensure the safety and stability of the bridge during the closure process. This application can optimize the stress distribution and dynamically monitor the structural stability during the closure process of the cable-stayed bridge, effectively prevent structural instability and local damage, and improve the safety and reliability of bridge construction.

[0097] See also Figure 2 , which is a schematic structural diagram of a closure monitoring device for a cable-stayed bridge provided in an embodiment of the present application, comprising:

[0098] A stress distribution acquisition unit 21 is used to perform stress analysis on the bridge closure stage based on a mechanical model of the bridge to acquire initial stress distribution;

[0099] The prestress distribution optimization unit 22 is used to adjust the prestress distribution strategy in the bridge closure stage based on the initial stress distribution to obtain the optimized prestress distribution;

[0100] A mechanical state adjustment unit 23, used to adjust the mechanical state of the closure point based on the prestress distribution;

[0101] The bridge stability judgment unit 24 is used to determine the stability of the bridge at the closure stage based on the mechanical state.

[0102] See also Figure 3 The embodiment of the present application further provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and executable on the processor. When the processor 320 executes the computer program 311, the steps of any one of the above-mentioned methods for monitoring the closure of a cable-stayed bridge are implemented.

[0103] Since the electronic device introduced in this embodiment is a device used to implement a closure monitoring device for a cable-stayed bridge in the embodiment of the present application, based on the method introduced in the embodiment of the present application, technical personnel in this field can understand the specific implementation mode of the electronic device of this embodiment and its various variations. Therefore, how the electronic device implements the method in the embodiment of the present application will not be described in detail here. As long as the equipment used by technical personnel in this field to implement the method in the embodiment of the present application is within the scope of protection of this application.

[0104] During the specific implementation process, when the computer program 311 is executed by a processor, any implementation method in the embodiments corresponding to the first aspect can be implemented.

[0105] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0106] Those skilled in the art will appreciate that the embodiments of the present application may provide methods, systems or computer program products. Therefore, the present application adopts the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present application adopts the form of a computer program product implemented on one or more computer-readable storage media containing computer-readable program code.

[0107] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0108] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0109] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0110] The present application also provides a computer program product, which includes computer software instructions. When the computer software instructions are executed on a processing device, the processing device executes Figure 1 A process of a closure monitoring method for a cable-stayed bridge in a corresponding embodiment.

[0111] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired or wireless means. The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a server or data center that includes one or more available media integration. The available medium can be a magnetic medium, an optical medium, or a semiconductor medium, etc.

[0112] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0113] In the several embodiments provided in the present application, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0114] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0115] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0116] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory, a random access memory, a magnetic disk or an optical disk.

[0117] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

[0118] Although the preferred embodiments of this specification have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of this specification.

[0119] Obviously, those skilled in the art can make various changes and modifications to this specification without departing from the spirit and scope of this specification. Thus, if these modifications and modifications of this specification fall within the scope of the claims of this specification and their equivalents, this specification is also intended to include these modifications and modifications.

Claims

1. A method for monitoring the closure of a cable-stayed bridge, characterized in that: The method comprises: Based on the mechanical model of the bridge, stress analysis is performed on the bridge closure stage to obtain the initial stress distribution; Based on the initial stress distribution, the prestress distribution strategy at the bridge closure stage is adjusted to obtain an optimized prestress distribution; Based on the prestress distribution, adjusting the mechanical state of the closure point; Based on the mechanical state, the stability of the bridge at the closure stage is determined.

2. The cable-stayed bridge closure monitoring method according to claim 1, characterized in that: The mechanical model is determined based on the following formula, expressed as: Among them, w(x, t) is the displacement of the steel truss at the position x at the joint point; M(x, t) is the bending moment at the position x; E is the elastic modulus of the steel; I is the section moment of inertia of the steel truss; x is the horizontal position coordinate of the steel truss; t is the time variable of the joint stage.

3. The cable-stayed bridge closure monitoring method according to claim 1, characterized in that: The method of regulating the prestress distribution strategy at the bridge closure stage based on the initial stress distribution to obtain an optimized prestress distribution includes: Based on the initial stress distribution, calculating the current stress distribution quality through an objective function; Based on the stress distribution quality, calculating the gradient of the objective function relative to the prestress distribution coefficient; Based on the gradient, updating the prestress distribution coefficient by a gradient descent method; Until the minimum value of the objective function is reached, the optimized prestress distribution is obtained.

4. The cable-stayed bridge closure monitoring method according to claim 3, characterized in that: The objective function is determined based on the following formula, expressed as: Among them, P i is the prestress of the i-th cable; σ i is the standard stress of cable i; λ is the regularization factor; dF / dx is the force change rate during the closure process; P is the vector of all prestressing forces; L is the length of the steel truss; N is the number of cables.

5. The cable-stayed bridge closure monitoring method according to claim 1, characterized in that: The adjusting the mechanical state of the closure point based on the prestress distribution includes: Based on the prestress distribution, determining the mechanical state at the current moment; Based on the mechanical state, for each time step, the mechanical state at the next moment is calculated according to a recursive formula to optimize the mechanical behavior of the bridge during the closure process, wherein the recursive formula is determined based on a feedback function.

6. The cable-stayed bridge closure monitoring method according to claim 5, characterized in that: The feedback function is determined based on the following formula, expressed as: Among them, f(P(t), u(f)) is the feedback function; P(t) is the prestress of the joint point at the tth moment; u(t) is the displacement vector at the current moment; is the objective function The gradient of the prestress at the joint point; α is the constant coefficient; du(t) / dt is the time derivative of the displacement; β is the damping coefficient.

7. The cable-stayed bridge closure monitoring method according to claim 1, characterized in that: Determining the stability of the bridge at the closure stage based on the mechanical state includes: Based on the mechanical state, calculating a stability index; Based on the stability index, an instability mode analysis is performed on the bridge during the closure stage to obtain an analysis result; Based on the analysis results, the stability of the bridge at the closure stage is determined.

8. A closure monitoring device for a cable-stayed bridge, characterized in that: include: The stress distribution acquisition unit is used to perform stress analysis on the bridge closure stage based on the mechanical model of the bridge and obtain the initial stress distribution; A prestress distribution optimization unit, used to adjust the prestress distribution strategy at the bridge closure stage based on the initial stress distribution to obtain an optimized prestress distribution; A mechanical state adjustment unit, used for adjusting the mechanical state of the closure point based on the prestress distribution; The bridge stability judgment unit is used to determine the stability of the bridge at the closure stage based on the mechanical state.

9. An electronic device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor is used to implement the steps of the cable-stayed bridge closure monitoring method as described in any one of claims 1 to 7 when executing the computer program stored in the memory.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the closure monitoring method for a cable-stayed bridge according to any one of claims 1 to 7 is implemented.

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