Suspension bridge short suspender cable force determination method and device and electronic equipment

Abstract

The present application relates to a kind of suspension bridge short suspender cable force determination method, belong to bridge detection, monitoring technical field, the method comprises: the cable force of long suspender of target suspension bridge is obtained;The unstressed length of main cable section of target suspension bridge is obtained;According to the cable force of long suspender and the unstressed length of main cable section, the horizontal force of main cable of target suspension bridge is obtained;The coordinates of short suspender area node are obtained, short suspender area node is the intersection of short suspender center line and main cable section center line, any two main cable section center line nodes of both sides of non-suspender area;According to the horizontal force of main cable and the coordinates of short suspender area node, the cable force of short suspender of target suspension bridge is obtained.The cable force of long suspender is obtained in the present application, and the horizontal force of main cable is further obtained, so that the cable force of short suspender is obtained by the horizontal force of main cable and the coordinates of short suspender node.

Description

Technical Field

[0001] This invention relates to the field of bridge inspection and monitoring technology, and in particular to a method, device and electronic equipment for determining the cable force of short suspension rods in suspension bridges. Background Technology

[0002] A suspension bridge is a bridge structure composed of cables, main towers, and a bridge deck. The cables, consisting of the main cable and suspenders, are high-strength steel cables or wires suspended from the main towers, primarily bearing the weight of the bridge. The main towers, as supporting structures, mainly function to support and stabilize the main cable. The bridge deck, typically constructed of concrete or steel, allows for vehicle and pedestrian traffic and is connected to the main cable via suspenders. Depending on the changing height of the main cable within the bridge span, the length of the suspenders at different locations will increase or decrease accordingly. To ensure the rationality of the main cable and bridge deck alignment, the initial length and elastic characteristics of the suspenders must be considered to guarantee the safety performance of the suspension bridge.

[0003] As a key component for force transmission between the main cable and the bridge deck, the measurement of cable force in suspender rods is an important task for monitoring and maintenance during the operation of suspension bridges. Two main techniques for measuring suspender cable force are: the frequency method, which uses accelerometers installed on the suspender rods to measure their vibration signals under environmental or human-induced excitation, determining their natural frequency and thus the cable force; and the magnetic flux method, which utilizes the magnetoelastic effect—the change in permeability of ferromagnetic components under force—to measure suspender cable force using magnetic flux sensors.

[0004] Existing technologies that obtain the cable force of suspenders using magnetic flux methods and frequency methods are easily affected by vibrations or magnetic field interference in the external environment, requiring shielding to reduce interference; moreover, each suspender needs to be measured individually, which is complex and costly, and cannot accurately measure the cable force of short suspenders with high stiffness. Summary of the Invention

[0005] In view of this, it is necessary to provide a method, device and electronic equipment for determining the cable force of short suspension bridge joists, so as to solve the problem that the existing technology cannot accurately measure the cable force of short suspension bridge joists with high stiffness.

[0006] To address the above problems, this invention provides a method for determining the cable force of a short suspension rod in a suspension bridge, comprising:

[0007] Obtain the cable force of the long suspender of the target suspension bridge;

[0008] Obtain the stress-free length of the main cable segment of the target suspension bridge;

[0009] The horizontal force of the main cable of the target suspension bridge is obtained based on the cable force of the long suspender and the stress-free length of the main cable segment.

[0010] Obtain the coordinates of the nodes in the short suspender area, wherein the nodes in the short suspender area include the intersection of the centerline of the short suspender and the centerline of the main cable section, as well as any two main cable section centerline nodes in the areas without suspenders on both sides of the short suspender;

[0011] The cable force of the short suspender of the target suspension bridge is obtained based on the horizontal force of the main cable and the coordinates of the short suspender node.

[0012] In one possible implementation, obtaining the horizontal force of the main cable of the target suspension bridge based on the cable force of the long suspender and the stress-free length of the main cable segment includes:

[0013] Based on the balance of cable forces at the long suspender node and the longitudinal catenary element equation, the horizontal force of the main cable of the target suspension bridge is obtained according to the cable force of the long suspender and the stress-free length of the main cable segments before and after the long suspender node.

[0014] In one possible implementation, the expression for the cable force balance at the long suspender node is:

[0015]

[0016] The expression for the equation of the longitudinal catenary element is:

[0017]

[0018]

[0019] In the formula, H x,k Indicates the horizontal force on the main cable; and These represent the longitudinal spacing between the front and rear ends of the k-th boom; This represents the vertical force at the k-th main cable node; The vertical force at the (k+1)th main cable node is represented by m; the mass of the main cable is represented by A. m E represents the cross-sectional area of ​​the main cable. m T represents the elastic modulus of the main cable. k This represents the cable force of the k-th boom; and These represent the stress-free lengths of the main cable segments before and after the k-th suspender.

[0020] In one possible implementation, the horizontal force of the main cable of the target suspension bridge is obtained based on the balance relationship of the cable forces at the long suspender node and the longitudinal catenary element equation, according to the cable forces of the long suspender and the stress-free lengths of the main cable segments before and after the long suspender node, including:

[0021] Based on the balance relationship of the cable forces at the suspender nodes and the longitudinal catenary element equations, the horizontal force at each long suspender node is obtained according to the cable force of each long suspender and the stress-free length of the main cable segments before and after each long suspender node.

[0022] The horizontal force of the main cable of the target suspension bridge is obtained based on the horizontal force at each long suspender node.

[0023] In one possible implementation, the horizontal force of the main cable of the target suspension bridge is obtained based on the balance relationship of the cable forces at the long suspender node and the longitudinal catenary element equation, according to the cable forces of the long suspender and the stress-free lengths of the main cable segments before and after the long suspender node, including:

[0024] Based on the balance relationship of the cable forces at the suspender nodes and the longitudinal catenary element equations, the horizontal force at each long suspender node is obtained according to the cable force of each long suspender and the stress-free length of the main cable segments before and after each long suspender node.

[0025] The horizontal force of the main cable of the target suspension bridge is obtained based on the horizontal force at each long suspender node.

[0026] In one possible implementation, obtaining the coordinates of the short boom region nodes includes: obtaining the coordinates of the short boom region nodes based on coordinate measurement or visual measurement methods.

[0027] In one possible implementation, the coordinates of the nodes in the short boom region are obtained based on visual measurement methods, including:

[0028] Based on image recognition technology, the features of the short suspender area are identified, including the intersection of the center line of the short suspender and the center line of the main cable, and any two main cable cross-section center line nodes in the areas without suspenders on both sides of the short suspender.

[0029] Based on the characteristics of the short rod region, the coordinates of the nodes in the short rod region are obtained.

[0030] In one possible implementation, obtaining the cable force of the target suspension bridge short suspender based on the horizontal force of the main cable and the coordinates of the short suspender node includes:

[0031] The longitudinal and vertical spacing of the short rod is determined based on the coordinates of the short rod node;

[0032] Based on the balance relationship of cable forces at the suspender node and the longitudinal and vertical catenary element equations, the cable forces of the short suspenders of the target suspension bridge are obtained according to the longitudinal and vertical spacing between the short suspenders and the horizontal force of the main cable.

[0033] On the other hand, the present invention also provides a device for determining the cable force of a short suspension bridge, comprising:

[0034] The long suspender cable force acquisition module is used to acquire the cable force of the long suspenders of the target suspension bridge;

[0035] The main cable segment length acquisition module is used to acquire the stress-free length of the main cable segment of the target suspension bridge;

[0036] The main cable horizontal force acquisition module is used to obtain the main cable horizontal force of the target suspension bridge based on the cable force of the long suspender and the stress-free length of the main cable segment.

[0037] The short suspender coordinate acquisition module is used to acquire the coordinates of the nodes in the short suspender area. The nodes in the short suspender area are the intersection of the center line of the short suspender and the center line of the main cable section, and any two center line nodes of the main cable section in the areas without suspenders on both sides.

[0038] The short suspender cable force acquisition module is used to obtain the cable force of the target suspension bridge short suspender based on the horizontal force of the main cable and the coordinates of the nodes in the short suspender area.

[0039] On the other hand, the present invention also provides an electronic device, including a memory and a processor, wherein,

[0040] The memory is used to store programs;

[0041] The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the method for determining the cable force of a short suspension bridge as described in any of the above implementations.

[0042] On the other hand, the present invention also provides a computer-readable storage medium for storing a computer-readable program or instruction, which, when executed by a processor, can implement the steps in the method for determining the cable force of a short suspension bridge as described in any of the above implementations.

[0043] The beneficial effects of this invention are as follows: This invention provides a method for determining the cable force of short hangers in a suspension bridge. First, the cable force of the long hangers and the stress-free length of the main cable segment of the target suspension bridge are obtained. Then, based on the cable force of the long hangers and the stress-free length of the main cable segment, the horizontal force of the main cable of the target suspension bridge is obtained. Furthermore, the coordinates of the corresponding nodes in the short hanger region are obtained. Finally, the cable force of the short hangers in the target suspension bridge is obtained based on the horizontal force of the main cable and the coordinates of the nodes in the short hanger region. This invention obtains the cable force of the long hangers by acquiring the cable force of the long hangers and further obtaining the horizontal force of the main cable, thereby obtaining the cable force of the short hangers through the horizontal force of the main cable and the coordinates of the short hanger nodes. Attached Figure Description

[0044] Figure 1 A flowchart illustrating an embodiment of the method for determining the cable force of a short suspension rod in a suspension bridge provided by the present invention;

[0045] Figure 2 This is a schematic diagram showing the connection of the main cable, hanger, and stiffening girder of a suspension bridge, according to an embodiment of a method for determining the cable force of a short suspender in a suspension bridge provided by the present invention.

[0046] Figure 3 This is a schematic diagram of a suspension bridge suspender and its front and rear main cable segments, representing an embodiment of a method for determining the cable force of a short suspender in a suspension bridge provided by the present invention.

[0047] Figure 4 This is a schematic diagram of the main cable stress in the short suspender area of ​​a suspension bridge, as provided by an embodiment of a method for determining the cable force of a short suspender in a suspension bridge according to the present invention.

[0048] Figure 5 For the present invention Figure 1 A schematic diagram of an embodiment of S105;

[0049] Figure 6 This is a schematic diagram of an embodiment of a device for determining the cable force of a short suspension rod in a suspension bridge provided by the present invention;

[0050] Figure 7 A schematic diagram of an embodiment of the electronic device provided by the present invention. Detailed Implementation

[0051] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0052] Figure 1 This is a schematic flowchart of an embodiment of a method for determining the cable force of a short suspension rod in a suspension bridge provided by the present invention, as shown below. Figure 1 As shown, a method for determining the cable force of a short hanger in a suspension bridge includes:

[0053] S101. Obtain the cable force of the long suspender of the target suspension bridge;

[0054] S102. Obtain the stress-free length of the main cable segment of the target suspension bridge;

[0055] S103. Based on the cable force of the long suspender and the stress-free length of the main cable segment, the horizontal force of the main cable of the target suspension bridge is obtained;

[0056] S104. Obtain the coordinates of the nodes in the short suspender area. The nodes in the short suspender area include the intersection of the center line of the short suspender and the center line of the main cable section, as well as any two main cable section center line nodes in the areas without suspenders on both sides of the short suspender.

[0057] S105. Based on the horizontal force of the main cable and the coordinates of the nodes in the short suspender area, the cable force of the short suspender of the target suspension bridge is obtained.

[0058] Compared with existing technologies, this embodiment provides a method for determining the cable force of short hangers in a suspension bridge. First, it obtains the cable force of the long hangers and the stress-free length of the main cable segment of the target suspension bridge. Then, based on the cable force of the long hangers and the stress-free length of the main cable segment, it obtains the horizontal force of the main cable of the target suspension bridge. Further, it obtains the coordinates of the nodes in the short hanger region. Finally, it obtains the cable force of the short hangers in the target suspension bridge based on the horizontal force of the main cable and the coordinates of the short hanger nodes. This invention obtains the cable force of the long hangers, further derives the horizontal force of the main cable, and then obtains the cable force of the short hangers through the horizontal force of the main cable and the coordinates of the nodes in the short hanger region.

[0059] In a specific embodiment of the present invention, step S101, obtaining the cable force of the long suspender of the target suspension bridge, includes:

[0060] The cable force of the target suspension bridge's long suspenders is obtained by installing sensors on the long suspenders, the sensors including one or more of an acceleration sensor or a magnetic flux sensor.

[0061] In some embodiments of the present invention, in step S102, the stress-free length of the main cable segment of the target suspension bridge is obtained, specifically as follows:

[0062] Assuming there are n suspenders within a span, there are n+1 main cable segments and n+2 main cable nodes. The suspender-free segments between nodes can be considered as catenary cable units. During the construction, completion, and subsequent operation of the suspension bridge, the stress-free length (i.e., the cutting length during construction) of each main cable segment remains unchanged. Therefore, the stress-free length of each segment can be determined based on the main cable cutting length information recorded in the completed bridge construction data.

[0063] In addition, the convergence shape of the main cable and the stress-free length of each segment can be calculated using traditional form-finding analysis methods based on the suspender cable force information in the designed bridge state. The longitudinal distance s between each main cable segment... x (If the distance between the hangers is known) and the coordinates of the control points are known, the calculation steps are as follows:

[0064] (1) The cable force of each suspender is taken as the cable force in the bridge state design. The quantity is known;

[0065] (2) Assuming the initial shape of the main cable is parabolic, calculate the initial horizontal force H at the end of the main cable according to parabolic theory. 0x and vertical force H 0z ;

[0066] (3) Each main cable segment between the suspenders is simulated sequentially using elastic catenary cable units, and the stress-free length of each catenary cable unit is calculated segment by segment. It has a vertical component of elongation.

[0067] (4) The coordinates of the main cable termination point and the vertical point are used as convergence conditions. If the coordinates calculated in the previous step do not meet the requirements, the main cable end force needs to be updated iteratively until the coordinate error meets the requirements.

[0068] (5) Obtain the convergent linear shape and extract the stress-free length of all catenary wire elements.

[0069] Using the two methods described above, we can obtain the stress-free length of the main cable segment that remains constant throughout the construction and operation of the suspension bridge, and provide known parameters for subsequent steps.

[0070] In a specific embodiment of the present invention, the frequency method measures the vibration signal of the boom under environmental or artificial excitation by installing an acceleration sensor on the boom, and determines the natural frequency of the boom by filtering, amplification and spectrum analysis, and finally determines the cable force based on the relationship between the frequency and the cable force.

[0071] The key to this method of accurately measuring cable force lies in precisely determining the fundamental frequency f and the effective calculation length L0 of the cable, in order to calculate the quantitative relationship between the natural frequency of the shunt and the cable force. Existing research shows that the frequency method has high accuracy in measuring the cable force of long shunts (referring to shunts that are close to the main tower and have a relatively long length), but its accuracy is very low when measuring short shunts. Therefore, in order to take advantage of its advantages and minimize subsequent calculation errors, the cable force of multiple long shunts can be measured.

[0072] For a single suspension rod, a beam model with both ends fixed is used as the calculation model for cable force, making the calculated cable force value closer to the actual solution. The cable force calculation formula is as follows:

[0073]

[0074] In the formula, m h denoted as ρ is the linear density of the hanger; E is the elastic modulus of the hanger; I is the bending stiffness of the hanger, which is related to the cross-sectional properties; f0 is the fundamental frequency of the hanger; and L0 is the effective calculated length of the hanger.

[0075] The accurate values ​​of f0 and L0 are crucial to the solution accuracy of equation (1). f0 is obtained through vibration testing with external excitation, and L0 should remove the differences in stiffness and mass per unit length between the anchor head and the flexible cable segment, as well as the influence of the cable clamp. Figure 2 The diagram shows the actual connection of the main cable, suspenders, and stiffening girder of a suspension bridge. The main cable and suspenders are connected by cable clamps, and the suspenders and stiffening girder are connected by anchorages. Therefore, the effective calculated length of long suspenders needs to account for the influence of both to ensure consistency in the selected segments and obtain more accurate cable force values. The expression for the effective calculated length is as follows:

[0076] L0 = L - (L1 + L2) (2)

[0077] Where L is the distance between the main cable node and the anchor plate at the lower end of the long suspender; L1 is the length of the rigid anchor head of the long suspender, which has much greater stiffness than the rest of the long suspender; and L2 is the length of the cable clamp at the upper end of the long suspender.

[0078] The magnetic flux method utilizes a magnetic flux sensor. The boom, as a ferromagnetic component, exhibits a magnetoelastic effect where its permeability changes under stress. The cable force is obtained based on the relationship between the boom's stress, strain, induced voltage, and boom length. The induced voltage U... f The length L0 of the boom is a key parameter for solving the problem, and the relationship between the two and the cable force can be derived as follows:

[0079]

[0080] In the formula, ΔL is the axial elongation of the boom; μ0 is the permeability of free space; A0 is the cross-sectional area inside the induction coil; U e U is the induced voltage of the boom when it is unloaded; f U0 is the induced voltage when the boom is under tension; U0 is the induced voltage when there is no boom in the induction coil; λ s M is the saturation magnetostriction coefficient; s K represents the saturation magnetization. μ θ is the uniaxial anisotropy constant; θ0 is the angle between the external magnetic field and the easy magnetization axis; H is the external magnetic field strength.

[0081] In actual measurement operations, it is not necessary to obtain all the parameters listed in equation (3), E, ​​A0, λ s M s K μ H, θ0, U e Both U0 and λ are constants, and λ is a constant. s M s K μ H and θ0 are generally difficult to measure directly, therefore T i with U f The linear relationship between them is obtained through calibration in actual measurements.

[0082] Using the two methods described above, and by directly measuring the relevant parameters through corresponding sensors, the cable forces T1, T2, ..., T of t-length suspension rods can be obtained with relatively high accuracy. t .

[0083] In some embodiments of the present invention, step S103, which involves obtaining the horizontal force of the main cable of the target suspension bridge based on the cable force of the long suspender and the stress-free length of the main cable segment, includes:

[0084] Based on the balance of cable forces at the long suspender node and the longitudinal catenary element equation, the horizontal force of the main cable of the target suspension bridge is obtained according to the cable force of the long suspender and the stress-free length of the main cable segments before and after the long suspender node.

[0085] In some embodiments of the present invention, the expression for the balance relationship of the cable forces at the long suspender node is as follows:

[0086]

[0087] The expression for the equation of the longitudinal catenary element is:

[0088]

[0089]

[0090] In the formula, H x,k Indicates the horizontal force on the main cable; and These represent the longitudinal spacing between the front and rear ends of the k-th boom; This represents the vertical force at the k-th main cable node; The vertical force at the (k+1)th main cable node is represented by m; the mass of the main cable is represented by A. m E represents the cross-sectional area of ​​the main cable. m T represents the elastic modulus of the main cable. k This represents the cable force of the k-th boom; and These represent the stress-free lengths of the main cable segments before and after the k-th suspender.

[0091] In some embodiments of the present invention, the method of obtaining the horizontal force of the main cable of the target suspension bridge based on the balance relationship of the cable force at the long suspender node and the longitudinal catenary element equation according to the cable force of the long suspender and the stress-free length of the main cable segments before and after the long suspender node includes:

[0092] Based on the balance relationship of the cable forces at the suspender nodes and the longitudinal catenary element equations, the horizontal force at each long suspender node is obtained according to the cable force of each long suspender and the stress-free length of the main cable segments before and after each long suspender node.

[0093] The horizontal force of the main cable of the target suspension bridge is obtained based on the horizontal force at each long suspender node.

[0094] In one possible implementation, the horizontal force of the main cable of the target suspension bridge is obtained based on the balance relationship of the cable forces at the long suspender node and the longitudinal catenary element equation, according to the cable forces of the long suspender and the stress-free lengths of the main cable segments before and after the long suspender node, including:

[0095] Based on the balance relationship of the cable forces at the suspender nodes and the longitudinal catenary element equations, the horizontal force at each long suspender node is obtained according to the cable force of each long suspender and the stress-free length of the main cable segments before and after each long suspender node.

[0096] The horizontal force of the main cable of the target suspension bridge is obtained based on the horizontal force at each long suspender node.

[0097] In some embodiments of the present invention, in step S103, the horizontal force of the main cable of the target suspension bridge is obtained based on the cable force of the long suspender and the stress-free length of the main cable segment, specifically as follows:

[0098] Based on the cable force of the t-length suspender measured in step S101 and the stress-free length of the main cable segment obtained in step S102, as follows: Figure 3 As shown, the precise value of the horizontal force of the main cable in the current state of the suspension bridge can be obtained by measuring the force of a single suspender cable.

[0099] For any one of the t-length booms, boom k (k = 1, ..., t), its boom force is T. k The stress-free lengths of the preceding and following main cable segments connected to it are respectively and The longitudinal spacing of the hangers is and Based on the force balance at the nodes and the equations of the longitudinal catenary element, the parameter relationships of the main cable nodes and elements can be expressed as follows:

[0100]

[0101]

[0102]

[0103] In the formula, H x,k The horizontal force of the main cable should be kept consistent across all main cable segments. The vertical force at the k-th main cable node; m is the weight of the main cable; A m Main cable cross-sectional area; E m The elastic modulus of the main cable;

[0104] In equations (4)-(6), parameter E m A m 'm' are inherent parameters of the component, which can be determined after information such as the main cable material is determined. Given the design parameters, T k , The known parameters for the main cable and suspender components are determined through steps S101 and S102. H is a key decoupling parameter. x,k , and At this point, there are three equations that correspond to the three unknowns mentioned above. By substituting the corresponding known parameters, we can obtain an exact and unique solution.

[0105] Since an accurate solution for the horizontal force of the main cable is crucial for calculating the cable force of the short suspenders in subsequent steps, to reduce the random errors caused by measuring a single suspender, the measured cable force of t suspenders can be processed, and H can be calculated using a single suspender and its adjacent main cable segments. x,k Then, average them:

[0106]

[0107] At this point, the key parameter H of the main cable segment catenary unit is... x Solution complete.

[0108] In some embodiments of the present invention, obtaining the coordinates of the nodes in the short boom area includes: obtaining the coordinates of the nodes in the short boom area based on coordinate measurement or visual measurement methods.

[0109] In some embodiments of the present invention, obtaining the coordinates of nodes in the short boom region based on a visual measurement method includes:

[0110] Based on image recognition technology, the features of the short suspender area are identified, including the intersection of the center line of the short suspender and the center line of the main cable, and any two main cable cross-section center line nodes in the areas without suspenders on both sides of the short suspender.

[0111] Based on the characteristics of the short rod region, the coordinates of the nodes in the short rod region are obtained.

[0112] In a specific embodiment of the present invention, in step S104, the coordinates of the nodes in the short suspender area are obtained. The nodes in the short suspender area include the intersection of the centerline of the short suspender and the centerline of the main cable section, and any two main cable section centerline nodes in the areas without suspenders on both sides of the short suspender. Specifically:

[0113] like Figure 2 As shown, the intersection of the suspender centerline and the main cable cross-section centerline is the point where the suspender cable force acts on the main cable, and this intersection point is considered as the coordinate of the corresponding node of the main cable. Existing coordinate measurement methods, such as total stations, cannot accurately measure the main cable nodes at higher positions because the catwalks used during main cable construction are removed when the bridge is completed, and the equipment is relatively small. However, the coordinates of the main cable nodes located at the main cable anchorage point or in the short suspender area near the mid-span can be easily obtained using the above methods. Visual measurement methods can be used simply by taking photos of the corresponding main cable and using image recognition technology to identify the features of the corresponding nodes, thereby inferring the coordinates of the main cable nodes.

[0114] The steps for using a total station to identify the coordinates of the main cable nodes in the short suspender area are as follows:

[0115] (1) Preparatory work. In the short gantry survey area, select the intersection of the main cable and the bridge deck as the reference coordinate origin (i.e., the backsight point). Securely install the total station or theodolite on the tripod, adjust the instrument level, ensure the instrument is stable and check the accuracy; the line connecting the instrument center point and the backsight point is used as the reference baseline for measurement (i.e., the horizontal angle is 0).

[0116] (2) Angle Measurement. Starting from the reference point, aim at the r main cable feature nodes to be measured (i.e., Figure 2 (as described above), record the readings of the horizontal and vertical dials.

[0117] (3) Distance measurement. Based on the actual situation, input the value of the prism constant (PSM), aim at the main cable node to be measured, press the measurement key, and record and display the distance reading.

[0118] (4) Coordinate calculation. Based on the measured horizontal angles θ2…θ r vertical angle and distance l1…l r The coordinates of the main cable nodes are calculated using angle measurement formulas and distance formulas;

[0119] The horizontal distance between the reference coordinate origin and the instrument is:

[0120]

[0121] The relative ordinates and vertical coordinates of the remaining r+1 nodes can be represented as follows:

[0122]

[0123] (5) Complete the measurement, turn off the instrument, tidy up the equipment, and record the tidied node coordinates. The steps for identifying the main cable node coordinates in the short suspender area using visual measurement are as follows:

[0124] (1) On the longitudinal parallel line of the bridge at a corresponding distance from the main cable, take a series of images of the main cable along the line starting from the anchor point of the main cable, including the shape of the entire main cable within the short suspender area, and acquire image data. It is necessary to ensure that the image quality is good and that the features of the connection between the main cable and the cable clamp are clearly displayed.

[0125] (2) Perform noise reduction, enhancement and correction on the acquired images, use computer vision algorithms to extract feature points of the main cable nodes from the images, eliminate the influence of the suspender cable clamps, ensure that the coordinates of the main cable nodes are the coordinates of the center point of the circular cross section, and that the point is on the line of action of the suspender force, and obtain the coordinates of any two center points of the circular cross section of the main cable in the area without suspenders on both sides of the node coordinates.

[0126] (3) The similarity between features is compared by the matching algorithm of feature descriptors, the extracted features are matched with known node features, and the main cable image coordinates are converted into three-dimensional spatial coordinates by geometric calculation or image processing algorithms.

[0127] Both of these methods do not require contact with the main cable components, thus avoiding additional load and damage. In addition, they greatly reduce the workload of surveying personnel, improve work efficiency, and reduce risks.

[0128] In some embodiments of the present invention, in step S105, obtaining the cable force of the target suspension bridge short suspender based on the horizontal force of the main cable and the coordinates of the short suspender node includes:

[0129] S501. Determine the longitudinal and vertical spacing of the short rods based on the coordinates of the nodes in the short rod area;

[0130] S502. Based on the balance relationship of cable forces at the suspender node and the longitudinal and vertical catenary element equations, the cable forces of the short suspenders of the target suspension bridge are obtained according to the longitudinal and vertical spacing between the short suspenders and the horizontal force of the main cable.

[0131] In a specific embodiment of the present invention, in step S105, the cable force of the target suspension bridge short suspender is obtained based on the horizontal force of the main cable and the coordinates of the nodes in the short suspender area, specifically as follows:

[0132] like Figure 4 The diagram shown is a schematic representation of the main cable stress in the short suspender region of a suspension bridge, according to an embodiment of the method for determining cable force in a short suspender section of a suspension bridge provided by this invention. The main cable is a continuous curve, bearing concentrated cable force only at corresponding nodes, with the section bearing its own weight in the middle considered as a catenary. For solving a specific catenary element, there exists a horizontal force H. x Vertical force H z Segmental horizontal projections x Segmental vertical projection s z There are 5 variables, including the stress-free length s0 of the segment, and 2 expressions relating the longitudinal and vertical projections. Therefore, based on the horizontal force of the main cable determined in step 103 and the projections of the main cable segments in each direction obtained in step 4, we can decouple the other 2 variables from expressions (4) and (6), which can be expressed in the following implicit form:

[0133]

[0134] In the above formula, r is the number of short rods to be determined, and the coordinates of r+2 corresponding nodes need to be measured; This provides the prerequisite for calculating the cable force of the short suspenders below, which is the main cable between the two short suspenders. The accuracy of the horizontal force of the main cable obtained in step 3 can be determined. The calculated cable force at the upper end of the corresponding short suspender is then...

[0135]

[0136] It should be noted that the suspender cable force obtained through the above steps is the cable force at its upper anchor point (i.e., the intersection with the main cable). However, the suspender cable force at different locations will vary due to the suspender's own weight and the weight of the upper and lower anchors.

[0137] This invention proposes a method for determining the cable force of short hangers in suspension bridges. It fully leverages the advantages of mature technologies such as the frequency method or magnetic flux method, utilizing these approaches to measure the cable force of some long hangers. Based on the stress-free length of the corresponding main cable segment calculated from the designed bridge state, the accurate value of the horizontal force of the main cable is calculated according to the force balance relationship and the longitudinal catenary equation of the bridge. Then, the node coordinates of the main cable near the short hanger are identified using visual measurement, and the cable force of the short hanger is calculated using precise segmented catenary theory. This method fully combines the advantages of existing direct hanger cable force measurement methods with the main cable alignment characteristics, simplifying the measurement procedure, reducing workload, and overcoming the shortcomings of existing methods for measuring short hangers.

[0138] To better implement the method for determining the cable force of a short suspension bridge in this embodiment of the invention, based on the method for determining the cable force of a short suspension bridge, correspondingly, as follows: Figure 6 As shown, this embodiment of the invention also provides a device for determining the cable force of a short suspension bridge suspender. The device 600 for determining the cable force of a short suspension bridge suspender includes:

[0139] The long suspender cable force acquisition module 601 is used to acquire the cable force of the long suspenders of the target suspension bridge;

[0140] The main cable segment length acquisition module 602 is used to acquire the stress-free length of the main cable segment of the target suspension bridge;

[0141] The main cable horizontal force acquisition module 603 is used to obtain the main cable horizontal force of the target suspension bridge based on the cable force of the long suspender and the stress-free length of the main cable segment.

[0142] The short suspender coordinate acquisition module 604 is used to acquire the coordinates of the nodes in the short suspender area. The nodes in the short suspender area include the intersection of the center line of the short suspender and the center line of the main cable section, as well as any two main cable section center line nodes in the areas without suspenders on both sides of the short suspender.

[0143] The short suspender cable force acquisition module 605 is used to obtain the cable force of the target suspension bridge short suspender based on the horizontal force of the main cable and the coordinates of the short suspender node area.

[0144] The suspension bridge short suspender cable force determination device 200 provided in the above embodiments can realize the technical solution described in the above embodiment of the suspension bridge short suspender cable force determination method. The specific implementation principle of each module or unit can be found in the corresponding content of the above embodiment of the suspension bridge short suspender cable force determination method, which will not be repeated here.

[0145] like Figure 7 As shown, the present invention also provides an electronic device 700. The electronic device 700 includes a processor 701, a memory 702, and a display 703. Figure 7 Only some components of the electronic device 700 are shown, but it should be understood that it is not required to implement all the components shown, and more or fewer components may be implemented instead.

[0146] In some embodiments, processor 701 may be a central processing unit (CPU), microprocessor, or other data processing chip, used to run program code stored in memory 702 or process data, such as a method for determining the cable force of a short suspension bridge in this invention.

[0147] In some embodiments, processor 701 may be a single server or a group of servers. The server group may be centralized or distributed. In some embodiments, processor 701 may be local or remote. In some embodiments, processor 701 may be implemented on a cloud platform. In some embodiments, the cloud platform may include a private cloud, public cloud, hybrid cloud, community cloud, distributed cloud, internal cloud, multi-cloud, or any combination thereof.

[0148] In some embodiments, memory 702 may be an internal storage unit of electronic device 700, such as a hard disk or memory of electronic device 700. In other embodiments, memory 702 may also be an external storage device of electronic device 700, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on electronic device 700.

[0149] Furthermore, the memory 702 may include both internal storage units of the electronic device 700 and external storage devices. The memory 702 is used to store application software and various types of data installed on the electronic device 700.

[0150] In some embodiments, display 703 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. Display 703 is used to display information from electronic device 700 and to display a visual user interface. Components 701-703 of electronic device 700 communicate with each other via a system bus.

[0151] In one embodiment, when processor 701 executes a program for determining the cable force of a short suspension bridge boom stored in memory 702, the following steps can be implemented:

[0152] Obtain the cable force of the long suspender of the target suspension bridge;

[0153] Obtain the stress-free length of the main cable segment of the target suspension bridge;

[0154] The horizontal force of the main cable of the target suspension bridge is obtained based on the cable force of the long suspender and the stress-free length of the main cable segment.

[0155] Obtain the coordinates of the nodes in the short suspender area, wherein the nodes in the short suspender area include the intersection of the centerline of the short suspender and the centerline of the main cable section, as well as any two main cable section centerline nodes in the areas without suspenders on both sides of the short suspender;

[0156] The cable force of the short suspender of the target suspension bridge is obtained based on the horizontal force of the main cable and the coordinates of the nodes in the short suspender area.

[0157] It should be understood that when the processor 701 executes a program for determining the cable force of a short suspension bridge rod in the memory 702, in addition to the functions mentioned above, it can also perform other functions, as detailed in the description of the corresponding method embodiments above.

[0158] Furthermore, the embodiments of the present invention do not specifically limit the type of electronic device 700 mentioned. Electronic device 700 can be a mobile phone, tablet computer, personal digital assistant (PDA), wearable device, laptop computer, or other portable electronic device. Exemplary embodiments of portable electronic devices include, but are not limited to, portable electronic devices running iOS, Android, Microsoft, or other operating systems. The aforementioned portable electronic device can also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, electronic device 700 may not be a portable electronic device, but rather a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0159] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0160] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining the cable force of a short hanger in a suspension bridge, characterized in that, include: Obtain the cable force of the long suspender of the target suspension bridge; Obtain the stress-free length of the main cable segment of the target suspension bridge; The horizontal force of the main cable of the target suspension bridge is obtained based on the cable force of the long suspender and the stress-free length of the main cable segment. Obtain the coordinates of the nodes in the short suspender area, wherein the nodes in the short suspender area include the intersection of the centerline of the short suspender and the centerline of the main cable section, as well as any two main cable section centerline nodes in the areas without suspenders on both sides of the short suspender; The cable force of the short suspender of the target suspension bridge is obtained based on the horizontal force of the main cable and the coordinates of the nodes in the short suspender area.

2. The method for determining the cable force of a short suspension rod in a suspension bridge according to claim 1, characterized in that, The step of obtaining the horizontal force of the main cable of the target suspension bridge based on the cable force of the long suspender and the stress-free length of the main cable segment includes: Based on the balance relationship of cable forces at the long suspender node and the longitudinal catenary element equation, the horizontal force of the main cable of the target suspension bridge is obtained according to the cable force of the long suspender and the stress-free length of the main cable segments before and after the long suspender node.

3. The method for determining the cable force of a short suspension rod in a suspension bridge according to claim 2, characterized in that, The expression for the equilibrium relationship of the cable forces at the node of the long suspender is: The expression for the equation of the longitudinal catenary element is: In the formula, Indicates the horizontal force on the main cable; and They represent the first Longitudinal spacing between the front and rear of each suspension rod; Indicates the first Vertical force at each main cable node; Indicates the first +1 vertical force at the main cable node; Indicates the mass of the main cable; Indicates the cross-sectional area of ​​the main cable; Indicates the elastic modulus of the main cable; Indicates the first The cable tension of each boom; and They represent the first The stress-free length of the main cable segments before and after the suspender.

4. The method for determining the cable force of a short suspension rod in a suspension bridge according to claim 3, characterized in that, Based on the equilibrium relationship of cable forces at the long suspender node and the longitudinal catenary element equation, and according to the cable forces of the long suspender and the stress-free lengths of the main cable segments before and after the long suspender node, the horizontal force of the main cable of the target suspension bridge is obtained, including: Based on the balance relationship of cable forces at the long suspender nodes and the longitudinal catenary element equation, the horizontal force at each long suspender node is obtained according to the cable force of each long suspender and the stress-free length of the main cable segment before and after each long suspender node. The horizontal force of the main cable of the target suspension bridge is obtained based on the horizontal force at each long suspender node.

5. The method for determining the cable force of a short suspension rod in a suspension bridge according to claim 4, characterized in that, The step of obtaining the horizontal force of the main cable of the target suspension bridge based on the horizontal force at each long suspender node includes: The average horizontal force at each of the long suspender nodes is calculated to obtain the horizontal force of the main cable of the target suspension bridge.

6. The method for determining the cable force of a short suspension rod in a suspension bridge according to claim 1, characterized in that, The process of obtaining the coordinates of the nodes in the short boom area includes: The coordinates of the nodes in the short rod area are obtained based on coordinate measurement or visual measurement methods.

7. The method for determining the cable force of a short suspension rod in a suspension bridge according to claim 6, characterized in that, The coordinates of the nodes in the short rod area are obtained based on visual measurement methods, including: Based on image recognition technology, the features of the short suspender area are identified, including the intersection of the center line of the short suspender and the center line of the main cable, and any two main cable cross-section center line nodes in the areas without suspenders on both sides of the short suspender. Based on the characteristics of the short rod region, the coordinates of the nodes in the short rod region are obtained.

8. The method for determining the cable force of a short suspension rod in a suspension bridge according to claim 1, characterized in that, The step of obtaining the cable force of the target suspension bridge short suspender based on the horizontal force of the main cable and the coordinates of the nodes in the short suspender area includes: The longitudinal spacing between the short rods is determined based on the coordinates of the nodes in the short rod area. Based on the balance relationship of cable forces at the long suspender nodes and the longitudinal catenary element equation, the cable forces of the short suspenders of the target suspension bridge are obtained according to the longitudinal spacing between the front and rear of the short suspenders and the horizontal force of the main cable.

9. A device for determining the cable force of a short suspension rod in a suspension bridge, characterized in that, include: The long suspender cable force acquisition module is used to acquire the cable force of the long suspenders of the target suspension bridge; The main cable segment length acquisition module is used to acquire the stress-free length of the main cable segment of the target suspension bridge; The main cable horizontal force acquisition module is used to obtain the main cable horizontal force of the target suspension bridge based on the cable force of the long suspender and the stress-free length of the main cable segment. The short suspender coordinate acquisition module is used to acquire the coordinates of the nodes in the short suspender area. The nodes in the short suspender area include the intersection of the center line of the short suspender and the center line of the main cable section, as well as any two main cable section center line nodes in the areas without suspenders on both sides of the short suspender. The short suspender cable force acquisition module is used to obtain the cable force of the target suspension bridge short suspender based on the horizontal force of the main cable and the coordinates of the nodes in the short suspender area.

10. An electronic device, characterized in that, Including memory and processor, among which, The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the method for determining the cable force of a short suspension bridge as described in any one of claims 1 to 8.

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