Support stress parameter measuring method based on assembly type design

Abstract

The invention belongs to the technical field of bridge support monitoring, and discloses an assembly type design-based support stress parameter measurement method, which comprises the following steps of: symmetrically arranging four telescopic rods at four corners of an upper connecting steel plate and a lower connecting steel plate of a support, and mounting fiber grating strain sensors on the four telescopic rods for realizing a self-sensing function of the telescopic rods; and on the basis of strain response data acquired on each telescopic rod in real time, the displacement, the bearing reaction and the inclination angle of the support are monitored in real time through an established support parameter decoupling model. According to the technical scheme, the method for measuring the stress parameters of the support based on the assembly type design is introduced, the stress condition, the deformation degree and the dip angle change of the support can be accurately evaluated, and the health state of the support is comprehensively judged.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge bearing monitoring, and in particular relates to a bearing force parameter measurement method based on an assembled design. Background Art

[0002] Bridge bearings are an important part of the bridge superstructure and substructure. They are responsible for reliably transmitting the force and deformation of the superstructure to the substructure and coordinating the deformation of the two to ensure the safety and stability of the bridge. Bearings have been widely used in bridge engineering due to their simple structure, low price, and convenient processing, manufacturing and installation.

[0003] As the service life of bridges, traffic volume and traffic density increase significantly, the probability of problems with bridge bearings increases significantly. Once a bridge is damaged, the overall performance of the bridge structure will be reduced, and even the bridge will collapse, causing economic losses and threats to people's lives and property. Therefore, it is very important to monitor the performance of bridge bearings, including strain, support reaction, displacement, inclination, etc. However, traditional bridge bearing monitoring methods mainly rely on manual inspection and mechanical sensors. Manual inspection has problems such as strong subjectivity, low efficiency, and difficulty in real-time monitoring; mechanical sensors are easily affected by environmental factors and require regular maintenance. Most of the existing sensors for monitoring bearing performance are embedded, which not only makes it difficult to detect sensor damage, but also faces the problem of difficulty in replacement. Therefore, it is particularly important to study and develop new bearing monitoring methods to achieve comprehensive monitoring of bridge operation status. Summary of the invention

[0004] The purpose of the present invention is to provide a method for measuring the force parameters of a support based on an assembled design to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides a method for measuring bearing force parameters based on an assembled design, comprising:

[0006] Four retractable rods are arranged at four symmetrical corner positions between the upper and lower steel plates connected to the support, and a strain sensor is installed on each of the retractable rods to realize the self-sensing function of the support.

[0007] Optionally, calculate the displacement of the support, including:

[0008] The coordinate system is constructed with the center of the steel plate as the origin, and the plane deformation model is constructed based on the coordinates of each retractable rod;

[0009] The plane deformation model specifically includes:

[0010] y=ax+bz+c

[0011] Wherein, y is the vertical displacement of a point on the surface of the upper steel plate, x and z are the coordinates of the point in the horizontal plane, a and b are the inclinations of the plane in the x and z directions, and c is the initial displacement in the vertical direction, where a>0 means that the support steel plate is inclined in the positive x direction, a<0 ​​means that the support steel plate is inclined in the negative x direction, b>0 means that the support steel plate is inclined in the positive z direction, b<0 means that the support steel plate is inclined in the negative z direction, and c is the initial displacement of the support steel plate in the vertical direction;

[0012] Constructing a displacement equation group based on the displacement change of each of the retractable rods;

[0013] The displacement equation group specifically includes:

[0014] ΔL1=a·x1+b·z1+c

[0015] ΔL2=a·x2+b·z2+c

[0016] ΔL3=a·x3+b·z3+c

[0017] ΔL4=a·x4+b·z4+c

[0018] Wherein, ΔL1 is the vertical displacement change of telescopic rod 1, ΔL2 is the vertical displacement change of telescopic rod 2, ΔL3 is the vertical displacement change of telescopic rod 3, ΔL4 is the vertical displacement change of telescopic rod 4, x1 and z1 are the coordinates of telescopic rod 1 in the horizontal plane, x2 and z2 are the coordinates of telescopic rod 2 in the horizontal plane, x3 and z3 are the coordinates of telescopic rod 3 in the horizontal plane, x4 and z4 are the coordinates of telescopic rod 4 in the horizontal plane, a and b represent the inclination of the plane in the x and z directions, and c is the initial displacement in the vertical direction;

[0019] The displacement equation group is solved to obtain the plane equation coefficients, and the plane equation coefficients are substituted into the plane deformation model to obtain the plane deformation of the support. After the plane deformation of the support is obtained by solving the coordinates within the range of the support, the corresponding displacement value of the support at this coordinate can be calculated, thereby realizing all-round displacement monitoring of the support.

[0020] Optionally, calculate the support reaction forces, including:

[0021] F i =ε i ·E·A

[0022] In the formula, F i is the support reaction force of the telescopic rod, ε i is the strain of the telescopic rod, E is the elastic modulus of the telescopic rod material, and A is the cross-sectional area of ​​the telescopic rod.

[0023] Optionally, calculate the inclination angle of the support, including:

[0024] The calculation process of the inclination angle of the support specifically includes:

[0025] Calculating the tilt angle data of the support in the X direction and the Z direction based on the displacement change data of each of the telescopic rods; calculating the tilt angle of the support based on the tilt angle data in each direction;

[0026] The calculation formula of the inclination angle data in the X direction is:

[0027]

[0028] In the formula, θ x1 is the inclination angle of the support in the X direction on the side of telescopic rod 4 and telescopic rod 1, Δy x1 is the difference in displacement between telescopic rod 4 and telescopic rod 1 in the X direction, L x is the original length of the telescopic rod in the X direction, θ x2 is the inclination angle of the support in the X direction on the side of telescopic rod 3 and telescopic rod 2, Δy x2 is the difference in displacement between telescopic rod 3 and telescopic rod 2 in the X direction, L x is the original length of the telescopic rod in the X direction; θ x is the inclination angle of the support in the X direction;

[0029] The calculation formula of the tilt angle data in the Z direction is:

[0030]

[0031] In the formula, θ z1 is the inclination angle of the support in the Z direction on the side of telescopic rod 1 and telescopic rod 2, Δy z1 is the difference in displacement between telescopic rod 1 and telescopic rod 2 in the Z direction, L z is the original length of the telescopic rod in the Z direction; θ z2 is the inclination angle of the support in the Z direction on the side of telescopic rod 4 and telescopic rod 3, Δy z2 is the difference in displacement between telescopic rod 4 and telescopic rod 3 in the Z direction, L z is the original length of the telescopic rod in the Z direction; θ z is the inclination angle of the support in the Z direction;

[0032] The calculating the inclination angle of the support based on the inclination angle data in each direction specifically includes:

[0033]

[0034] Where θ is the inclination angle of the support, θ xis the inclination angle of the support in the X direction, θ z is the inclination angle of the support in the Z direction.

[0035] The technical effects of the present invention are:

[0036] The present invention can obtain the strain, support reaction force and inclination information of bridge bearings under different working conditions. Using these identified parameter information, the stress condition, deformation degree and inclination change of the bearing can be accurately evaluated, and the health status of the bearing can be comprehensively judged, thereby effectively ensuring the safety and stability of the bridge structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] The drawings constituting a part of this application are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an improper limitation on this application.

[0039] Figure 1 is an implementation flow chart of an embodiment of the present invention;

[0040] Figure 2 is a strain diagram of the telescopic rod of the support in the embodiment of the present invention;

[0041] Figure 3 is a calculation diagram of the support inclination angle in the X direction in an embodiment of the present invention;

[0042] Figure 4 It is a calculation diagram of the inclination angle of the support in the Z direction in the embodiment of the present invention;

[0043] Figure 5 It is a schematic diagram of a finite element model of a 25m concrete box simply supported beam bridge and a prefabricated bearing in an embodiment of the present invention;

[0044] Figure 6 is a diagram showing the simulated value and theoretical value of the displacement of the telescopic rod of the support in the embodiment of the present invention; wherein, Figure 6 (a) is the displacement value of the telescopic rod of the support in working condition 1 in the embodiment of the present invention; Figure 6 (b) is the displacement value of the telescopic rod of the support in working condition 2 in the embodiment of the present invention; Figure 6 (c) is the displacement value of the telescopic rod of the support in working condition 3 in the embodiment of the present invention;

[0045] Figure 7is an error diagram between the simulated displacement value and the theoretical displacement value of the telescopic rod of the support in the embodiment of the present invention; wherein, Figure 7 (a) is an error diagram between the simulated displacement value and the theoretical displacement value of the telescopic rod of the support in the working condition 1 in the embodiment of the present invention; Figure 7 (b) is an error diagram of the simulated displacement value and the theoretical value of the telescopic rod of the support in the working condition 2 in the embodiment of the present invention; Figure 7 (c) is an error diagram of the simulated displacement value and the theoretical value of the telescopic rod of the support in the working condition 3 in the embodiment of the present invention;

[0046] Figure 8 is the inclination angle of the support under different working conditions in the embodiment of the present invention; wherein, Figure 8 (a) is the inclination angle of the support in working condition 1 in the embodiment of the present invention; Figure 8 (b) is the inclination angle of the support in working condition 2 in the embodiment of the present invention; Figure 8 (c) is the inclination angle of the support in working condition 3 in the embodiment of the present invention;

[0047] Fig. 9 : is a support reaction diagram of the telescopic rod of the support under different working conditions in the embodiment of the present invention; wherein, Fig. 9 (a) is a support reaction diagram of the telescopic rod of the support in working condition 1 in an embodiment of the present invention; Fig. 9 (b) is a support reaction diagram of the telescopic rod of the support in working condition 2 in an embodiment of the present invention; Fig. 9 (c) is the support reaction diagram of the telescopic rod of the support in working condition three in the embodiment of the present invention. DETAILED DESCRIPTION

[0048] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0049] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0050] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art generally understood by the present invention. Although the present invention describes only preferred methods, any method similar or equivalent to that described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0051] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0052] The words “include,” “including,” “have,” “contain,” etc. used in this article are open-ended terms, meaning including but not limited to.

[0053] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0054] Embodiment 1

[0055] like Figure 1 - Fig. 9 As shown, this embodiment provides a method for measuring the force parameters of a support based on an assembled design, including: arranging four retractable rods at four symmetrical corner positions between the upper and lower steel plates connected to the support, and installing a strain sensor on each of the retractable rods to realize the self-sensing function of the support.

[0056] This embodiment can obtain the strain, support reaction force and inclination information of the bridge bearing under different working conditions. Using these identified parameter information, the stress condition, deformation degree and inclination change of the bearing can be accurately evaluated, and the health status of the bearing can be comprehensively judged, thereby effectively ensuring the safety and stability of the bridge structure.

[0057] The purpose of this embodiment is to solve the problems of strong subjectivity, low efficiency, and great influence of environmental factors in traditional methods of bridge bearing monitoring, so as to improve the accuracy and reliability of bearing performance monitoring. By introducing a bearing force parameter identification method based on prefabricated design, higher flexibility and adaptability can be achieved in the monitoring of bearing displacement, bearing reaction force, inclination and other parameters. This embodiment provides a more scientific and effective basis for the monitoring of bridge bearings, and enhances the monitoring effect of bridge bearings under various complex working conditions.

[0058] This embodiment proposes a bearing force parameter measurement method based on prefabricated design to improve the accuracy and reliability of bridge bearing monitoring. At the same time, it provides effective technical support for real-time monitoring of bearing force parameters to ensure the safety and stability of the bridge structure. Figure 1 It is the theoretical roadmap of the technical solution of this embodiment.

[0059] 1. Support self-sensing monitoring:

[0060] The self-sensing monitoring of the support is achieved by arranging four retractable rods symmetrically at the four corners of the upper and lower steel plates of the support, and each rod is equipped with a fiber Bragg grating (FBG) strain sensor. The design of the retractable rod avoids the error caused by the bending of the sensor and ensures that the sensor can freely expand and contract with the deformation of the support. This design significantly enhances the adaptability and flexibility of the monitoring system and effectively overcomes the limitations of traditional support monitoring methods.

[0061] 2. Strain reconstruction displacement theory: Based on the FBG sensor, the strain data of the telescopic rod of the support is obtained in real time, and the displacement of the support can be further calculated through the strain data. The relationship between strain ε and displacement is expressed by the following formula:

[0062]

[0063] Where ε is the strain of the telescopic rod, ΔL is the displacement change of the telescopic rod, and L is the original length of the telescopic rod.

[0064] 2.1. Strain data acquisition: The strains of the four retractable rods of the support are obtained in real time through the FBG sensor, which are ε1, ε2, ε3 and ε4, as shown in Figure 2 shown.

[0065] 2.2. Calculate the displacement change of each telescopic rod: Use the strain formula to calculate the displacement change of each telescopic rod:

[0066]

[0067] Wherein, ε1 is the strain of telescopic rod 1, ε2 is the strain of telescopic rod 2, ε3 is the strain of telescopic rod 3, ε4 is the strain of telescopic rod 4, ΔL1 is the displacement change of telescopic rod 1, ΔL2 is the displacement change of telescopic rod 2, ΔL3 is the displacement change of telescopic rod 3, ΔL4 is the displacement change of telescopic rod 4, and L is the original length of the telescopic rod.

[0068] 2.3. Establish displacement model: In order to deduce the overall deformation of the support from the displacement change of the telescopic rod, the position and geometric relationship of the telescopic rod need to be considered.

[0069] (1) Setting the coordinate system: Taking the center of the bottom steel plate of the bridge support 1 as the origin O, set the position coordinates (x, y) of the four telescopic rods: telescopic rod 1: (x1, z1), telescopic rod 2: (x2, z2), telescopic rod 3: (x3, z3), telescopic rod 4: (x4, z4).

[0070] (2) Plane deformation model: After the bridge bearing is subjected to force, it is assumed that the top steel plate of the bearing undergoes plane deformation. The top steel plate of the bearing forms a plane after being subjected to force. Its shape can be expressed by a plane equation:

[0071] y=ax+bz+c(3)

[0072] Where y is the vertical displacement of a point on the upper plate surface, x and z are the coordinates of the point in the horizontal plane, a and b represent the inclination of the plane in the x and z directions, and c is the initial displacement in the vertical direction.

[0073] (3) Establishing a set of equations: Based on the displacement change of the top end of the telescopic rod, the following four equations are obtained:

[0074]

[0075] Wherein, ΔL1 is the vertical displacement change of telescopic rod 1, ΔL2 is the vertical displacement change of telescopic rod 2, ΔL3 is the vertical displacement change of telescopic rod 3, ΔL4 is the vertical displacement change of telescopic rod 4, x1 and z1 are the coordinates of telescopic rod 1 in the horizontal plane, x2 and z2 are the coordinates of telescopic rod 2 in the horizontal plane, x3 and z3 are the coordinates of telescopic rod 3 in the horizontal plane, x4 and z4 are the coordinates of telescopic rod 4 in the horizontal plane, a and b represent the inclination of the plane in the x and z directions, and c is the initial displacement in the vertical direction.

[0076] (4) Solve the equations: Substitute the displacement ΔL obtained by strain calculation i Substitute into the equations above and solve for the coefficients a, b, and c of the plane equation.

[0077] 2.4. Analysis of plane deformation: By solving a, b and c, determine the plane deformation of the top steel plate of the support. After solving a, b and c, the plane equation is obtained:

[0078] y=ax+bz+c(5)

[0079] Where y is the vertical displacement of a point on the steel plate surface, x and z are the coordinates of the point in the horizontal plane, a and b represent the inclination of the plane in the x and z directions, and c is the initial displacement in the vertical direction.

[0080] Among them, a>0 means that the support steel plate is tilted in the positive x direction, a<0 means that the support steel plate is tilted in the negative x direction, b>0 means that the support steel plate is tilted in the positive z direction, b<0 means that the support steel plate is tilted in the negative z direction, and c is the initial displacement of the support steel plate in the vertical direction.

[0081] After solving the plane deformation equation, as long as the coordinates within the support range are given, the corresponding displacement value of the support at this coordinate can be calculated, thus realizing all-round displacement monitoring of the support.

[0082] 3. Inclination angle and support reaction force theory:

[0083] 3.1. Calculate the inclination angle: The displacement of the four telescopic rods of the support is obtained through theoretical calculation: telescopic rod 1: Δy1, telescopic rod 2: Δy2, telescopic rod 3: Δy3, telescopic rod 4: Δy4

[0084] (1) Calculate the inclination angle of the support in the X direction

[0085] Support diagram for calculation of the inclination angle in the X direction, such as Figure 3 shown.

[0086] For telescopic rod 1 and telescopic rod 4 (at both ends in the X direction):

[0087] Δy x1 =Δy4-Δy1(6)

[0088] In the formula, Δy x1 is the difference between the displacement changes of telescopic rod 4 and telescopic rod 1 in the X direction, Δy4 is the displacement change of telescopic rod 4, and Δy1 is the displacement change of telescopic rod 1.

[0089] According to the original length L of the telescopic rod of the support x , support θ x1 The tilt angle can be calculated by the following formula:

[0090]

[0091] In the formula, θ x1 is the inclination angle of the support in the X direction on the side of telescopic rod 4 and telescopic rod 1, Δy x1 is the difference in displacement between telescopic rod 4 and telescopic rod 1 in the X direction, L x is the original length of the telescopic rod in the X direction.

[0092] For telescopic rod 2 and telescopic rod 3 (at both ends in the X direction):

[0093] Δy x2 =Δy3-Δy2(8)

[0094] In the formula, Δyx2 is the difference between the displacements of telescopic rod 3 and telescopic rod 2 in the X direction, Δy3 is the displacement of telescopic rod 3, and Δy2 is the displacement of telescopic rod 2.

[0095] According to the original length L of the telescopic rod of the support x , support θ x2 The tilt angle can be calculated by the following formula:

[0096]

[0097] In the formula, θ x2 is the inclination angle of the support in the X direction on the side of telescopic rod 3 and telescopic rod 2, Δy x2 is the difference in displacement between telescopic rod 3 and telescopic rod 2 in the X direction, L x is the original length of the telescopic rod in the X direction.

[0098] The tilt angle of the support in the X direction:

[0099]

[0100] In the formula, θ x is the inclination angle of the support in the X direction, θ x1 is the inclination angle of the support in the X direction on the side of telescopic rod 4 and telescopic rod 1, θ x2 It is the inclination angle of the support in the X direction on the side of the telescopic rod 3 and the telescopic rod 2.

[0101] (2) Calculate the support inclination angle in the Z direction: The support diagram for calculating the inclination angle in the Z direction is as follows: Figure 4 shown.

[0102] For telescopic rod 1 and telescopic rod 2 (at both ends in the Z direction):

[0103] Δy z1 =Δy1-Δy2(11)

[0104] In the formula, Δy z1 is the difference in displacement between telescopic rod 1 and telescopic rod 2 in the Z direction, Δy1 is the displacement of telescopic rod 1, and Δy2 is the displacement of telescopic rod 2.

[0105] According to the original length L of the telescopic rod of the support z , support θ z1 The tilt angle can be calculated by the following formula:

[0106]

[0107] In the formula, θ z1is the inclination angle of the support in the Z direction on the side of telescopic rod 1 and telescopic rod 2, Δy z1 is the difference in displacement between telescopic rod 1 and telescopic rod 2 in the Z direction, L z The original length of the telescopic rod in the Z direction.

[0108] For telescopic rod 3 and telescopic rod 4 (at both ends in the Z direction):

[0109] Δy z2 =Δy4-Δy3(13)

[0110] In the formula, Δy z2 is the difference between the displacement changes of telescopic rod 4 and telescopic rod 3 in the Z direction, Δy4 is the displacement change of telescopic rod 4, and Δy3 is the displacement change of telescopic rod 3.

[0111] According to the original length L of the telescopic rod of the support z , support θ z2 The tilt angle can be calculated by the following formula:

[0112]

[0113] In the formula, θ z2 is the inclination angle of the support in the Z direction on the side of telescopic rod 4 and telescopic rod 3, Δy z2 is the difference in displacement between telescopic rod 4 and telescopic rod 3 in the Z direction, L z is the original length of the telescopic rod in the Z direction.

[0114] The tilt angle of the support in the Z direction:

[0115]

[0116] In the formula, θ z is the inclination angle of the support in the Z direction, θ z1 is the inclination angle of the support in the Z direction on the side of telescopic rod 1 and telescopic rod 2, θ z2 It is the inclination angle of the support in the Z direction on the side of the telescopic rod 4 and the telescopic rod 3.

[0117] (3) Composite inclination angle: Use the following formula to calculate the overall inclination angle θ of the support:

[0118]

[0119] Where θ is the overall inclination angle of the support, θ x is the inclination angle of the support in the X direction, θ z is the inclination angle of the support in the Z direction.

[0120] 3.2 Calculation of support reaction force: The support reaction force of each retractable rod is calculated by the FBG strain data of the four retractable rods of the support. The support reaction force F of each retractable rod is i It can be obtained through the support reaction strain relationship of the telescopic rod material:

[0121] F i =ε i ·E·A(17)

[0122] In the formula, F i is the support reaction force of the telescopic rod, ε i is the strain of the telescopic rod, E is the elastic modulus of the telescopic rod material, and A is the cross-sectional area of ​​the telescopic rod.

[0123] According to the above-mentioned bearing force parameter identification theory, by extracting the strain response data of the retractable rod of the bearing under different working conditions, the bearing force state can be accurately identified, and its key parameters such as displacement, support reaction force and inclination angle can be accurately determined. This method realizes the accurate identification of bearing force and deformation information, thereby fully restoring the bearing force distribution under the actual load, providing a reliable means for monitoring and evaluating bridge bearings.

[0124] Specific algorithm examples of this embodiment include:

[0125] This example simulates a 25-meter-long box-type simply supported beam bridge with uniform cross-section to verify a bearing force parameter measurement method based on prefabricated design. Four bearings with prefabricated design are installed on the cap beams at both ends of the simply supported beam bridge. The geometric and position information of the bearings and four retractable rods equipped with FBG sensors are as follows:

[0126] The overall size of the support is 40cm×40cm×9.1cm. The support structure is as follows from bottom to top: the bottom steel plate, with a size of 40cm×40cm×2cm; the middle is a cylindrical steel plate with a diameter of 30cm and a height of 5.1cm, which is located at the center of the upper surface of the bottom steel plate and is in close contact with the bottom steel plate and the top steel plate; the top steel plate has a size of 40cm×40cm×2cm. Four telescopic rods are symmetrically installed at the four corners of the upper surface of the bottom steel plate and the lower surface of the top steel plate. The diameter of the telescopic rods is 2cm and the length is 5.1cm. The four telescopic rods are tightly connected to the bottom and top steel plates of the support. The arrangement of the four rods is as follows: telescopic rod 1 and telescopic rod 4 are in the same horizontal position, telescopic rod 1 and telescopic rod 2 are in the same longitudinal position, telescopic rod 2 and telescopic rod 3 are in the same horizontal position, and telescopic rod 3 and telescopic rod 4 are in the same longitudinal position.

[0127] The main beam of the simply supported beam bridge is made of C50 concrete. The finite element model of the simply supported beam bridge, the cross-sectional structure diagram of the main beam, and the finite element model of the prefabricated bearing are shown in the figure. Figure 5shown.

[0128] When loading the vehicle load, the model loads the vehicle on the double lanes of the bridge. The vehicle load is simplified by applying a vehicle with a length of 5m, a front axle spacing of 1.5m, a rear axle spacing of 3.5m, and axle loads of 60KN, 120KN, and 120KN, respectively, as shown in Table 1.

[0129] Table 1 Vehicle loading parameters

[0130]

[0131]

[0132] In order to determine the reliability of the bearing force parameter identification method based on prefabricated design in this embodiment and comprehensively consider the influence of vehicle loads at different positions of simply supported beam bridges, three working conditions are designed this time: working condition 1, vehicle load loading is carried out at the mid-span of the bridge; working condition 2, vehicle load loading is carried out at one-quarter of the bridge; working condition 3, vehicle load loading is carried out at the fulcrum of the bridge.

[0133] According to the three working conditions designed, the displacement values ​​of the four telescopic rods of the bridge support under the three working conditions are extracted, which are the simulated values ​​of the displacement of the telescopic rods of the support. Then, the strain values ​​of the four telescopic rods of each support are extracted, and the theoretical displacement values ​​are calculated by the strain reproduction displacement theory, and the displacement values ​​of the telescopic rods of the bridge support under the three working conditions are obtained, which are the theoretical values ​​of the displacement of the telescopic rods of the support. Figure 6 shown.

[0134] According to the distribution of the simulated displacement value and the theoretical displacement value of the telescopic rod of the support under the above three different working conditions, the error between the simulated displacement value and the theoretical displacement value of the telescopic rod of the support can be obtained as follows: Figure 7 shown.

[0135] According to Figure 7 The error diagram results of the finite element value and theoretical value of the displacement of the telescopic rod of the support show that the error between the simulated value and the theoretical value of the displacement of the telescopic rod of the support under each working condition is less than 5%, and the maximum error is 3.45%, which indicates that the support displacement parameter identification method based on prefabricated design proposed in this embodiment has high accuracy and robustness.

[0136] The displacement values ​​of the four telescopic rods of each support under different working conditions are obtained through theoretical calculation. The displacement data of the four telescopic rods of each support under different working conditions are substituted into the inclination angle of the support under different working conditions through the inclination angle calculation theory to evaluate the inclination of the support. Figure 8 shown.

[0137] according to Figure 8The support inclination diagram shows the overall inclination of the support under three different working conditions. From the results obtained, it can be seen that the inclination angles of the support under these three working conditions are very small, which indicates that the inclination state of the support under each different working condition is very healthy.

[0138] Through simulation, the strain of the four telescopic rods of each support under different working conditions is extracted, and the support reaction force of the four telescopic rods of each support under different working conditions is calculated by substituting into the support reaction force theory. Fig. 9 shown.

[0139] according to Fig. 9 The support reaction diagram of the support can obtain the support reaction forces of the four retractable rods of the support under three different working conditions, thereby identifying the stress state of the support.

[0140] Based on the above content, the displacement, support reaction force and inclination information of the bearing can be obtained, so as to further estimate the stress condition, deformation degree and inclination change of the bearing. These support parameter information are used to judge the health status of the bearing. When the displacement of the bearing increases, the support reaction force changes suddenly or the inclination changes significantly, these parameter changes provide effective technical support for the real-time monitoring of the bearing force parameters, thereby preventing the bearing abnormality from causing damage to the bridge structure.

[0141] This embodiment proposes a method for measuring the force parameters of a bridge bearing based on an assembled design. By symmetrically installing four retractable rods at the four corners of the upper and lower steel plates of the bearing, and equipping each rod with a fiber Bragg grating (FBG) strain sensor, the bending and inaccurate positioning of the sensor are effectively avoided, allowing it to deform freely with the bearing. This improvement realizes precise data acquisition, can accurately identify the displacement, support reaction force and inclination state of the bearing, and ensure the stability and reliability of the bridge bearing. In addition, the assembled design significantly simplifies the replacement and maintenance process of the sensor, reduces interference with the bridge structure, is conducive to the application of actual engineering projects, and promotes the development of bridge bearing monitoring.

[0142] This embodiment establishes a theory for identifying the stress parameters of bridge bearings. By extracting the strain data of the FBG sensors on the four rods of the bearing, key parameters such as the displacement, support reaction force and inclination of the bearing can be accurately identified. At the same time, monitoring the stress, deformation degree and inclination change of the bearing provides effective technical support for real-time monitoring of the stress parameters of the bearing, thereby preventing damage to the bridge structure due to bearing failure.

[0143] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for measuring bearing force parameters based on assembled design, characterized in that: include: Four retractable rods are arranged at four symmetrical corner positions between the upper and lower steel plates connected to the support, and a strain sensor is installed on each of the retractable rods to realize the self-sensing function of the support.

2. A method for measuring bearing force parameters based on assembly design according to claim 1, characterized in that: Calculate the displacement of the support, including: The coordinate system is constructed with the center of the steel plate as the origin, and the plane deformation model is constructed based on the coordinates of each retractable rod; The plane deformation model specifically includes: y=ax+bz+c Wherein, y is the vertical displacement of a point on the surface of the upper steel plate, x and z are the coordinates of the point in the horizontal plane, a and b are the inclinations of the plane in the x and z directions, and c is the initial displacement in the vertical direction, where a>0 means that the support steel plate is inclined in the positive x direction, a<0 ​​means that the support steel plate is inclined in the negative x direction, b>0 means that the support steel plate is inclined in the positive z direction, b<0 means that the support steel plate is inclined in the negative z direction, and c is the initial displacement of the support steel plate in the vertical direction; Constructing a displacement equation group based on the displacement change of each of the retractable rods; The displacement equation group specifically includes: ΔL1=a·x1+b·z1+c ΔL2=a·x2+b·z2+c ΔL3=a·x3+b·z3+c ΔL4=a·x4+b·z4+c Wherein, ΔL1 is the vertical displacement change of telescopic rod 1, ΔL2 is the vertical displacement change of telescopic rod 2, ΔL3 is the vertical displacement change of telescopic rod 3, ΔL4 is the vertical displacement change of telescopic rod 4, x1 and z1 are the coordinates of telescopic rod 1 in the horizontal plane, x2 and z2 are the coordinates of telescopic rod 2 in the horizontal plane, x3 and z3 are the coordinates of telescopic rod 3 in the horizontal plane, x4 and z4 are the coordinates of telescopic rod 4 in the horizontal plane, a and b represent the inclination of the plane in the x and z directions, and c is the initial displacement in the vertical direction; The displacement equation group is solved to obtain the plane equation coefficients, and the plane equation coefficients are substituted into the plane deformation model to obtain the plane deformation of the support. After the plane deformation of the support is obtained by solving the coordinates within the range of the support, the corresponding displacement value of the support at this coordinate can be calculated, thereby realizing all-round displacement monitoring of the support.

3. The method for measuring bearing force parameters based on assembly design according to claim 1 is characterized in that: Calculate the support reaction force, including: F i =e i ·E·A In the formula, F i is the support reaction force of the telescopic rod, ε i is the strain of the telescopic rod, E is the elastic modulus of the telescopic rod material, and A is the cross-sectional area of ​​the telescopic rod.

4. The method for measuring bearing force parameters based on assembly design according to claim 1 is characterized in that: Calculate the inclination angle of the support, including: The calculation process of the inclination angle of the support specifically includes: Calculating the tilt angle data of the support in the X direction and the Z direction based on the displacement change data of each of the telescopic rods; calculating the tilt angle of the support based on the tilt angle data in each direction; The calculation formula of the inclination angle data in the X direction is: In the formula, θ x1 is the inclination angle of the support in the X direction on the side of telescopic rod 4 and telescopic rod 1, Δy x1 is the difference in displacement between telescopic rod 4 and telescopic rod 1 in the X direction, L x is the original length of the telescopic rod in the X direction, θ x2 is the inclination angle of the support in the X direction on the side of telescopic rod 3 and telescopic rod 2, Δy x2 is the difference in displacement between telescopic rod 3 and telescopic rod 2 in the X direction, L x is the original length of the telescopic rod in the X direction; θ x is the inclination angle of the support in the X direction; The calculation formula of the tilt angle data in the Z direction is: In the formula, θ z1 is the inclination angle of the support in the Z direction on the side of telescopic rod 1 and telescopic rod 2, Δy z1 is the difference in displacement between telescopic rod 1 and telescopic rod 2 in the Z direction, L z is the original length of the telescopic rod in the Z direction; θ z2 is the inclination angle of the support in the Z direction on the side of telescopic rod 4 and telescopic rod 3, Δy z2 is the difference in displacement between telescopic rod 4 and telescopic rod 3 in the Z direction, L z is the original length of the telescopic rod in the Z direction; θ z is the inclination angle of the support in the Z direction; The calculating the inclination angle of the support based on the inclination angle data in each direction specifically includes: Where θ is the inclination angle of the support, θ x is the inclination angle of the support in the X direction, θ z is the inclination angle of the support in the Z direction.

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