Method for testing anti-overturning performance of single-column pier bridge after reinforcement

Abstract

The application discloses a kind of single-column pier bridge reinforcement post-anti-overturning performance test methods, it is related to bridge evaluation technical field, the method includes: obtaining bridge structure parameter, establishes finite element model including reinforcement structure to simulate working condition and identify the most unfavorable section;Accordingly, load and measurement scheme is formulated, and hierarchical synchronous jacking is executed by PLC jacking system, and constant load support reaction force is obtained;Then, eccentric load distribution jacking is carried out, and force and displacement data are fitted to obtain support vertical stiffness;Subsequently, eccentric loading is carried out, and stiffness value is converted eccentric load support reaction force;Finally, based on influence line arrangement most unfavorable load, monitor reinforcement component response, and all data are checked to calculate support reaction force and anti-overturning stability coefficient, and finally output the anti-overturning performance of bridge after reinforcement and reinforcement effect evaluation report.The method realizes the whole process accurate evaluation from theoretical analysis to field measurement, and provides important decision basis for the operation safety and later maintenance of single-column pier bridge after reinforcement.

Description

Technical Field

[0001] This invention relates to the field of bridge assessment technology, specifically to a test method for the overturning resistance performance of a single-column pier bridge after reinforcement. Background Technology

[0002] Single-column pier bridges are widely used in urban overpasses and ramp bridges due to their advantages such as lightweight structure, wide field of vision, and small footprint. However, several collapses of single-column pier bridges in recent years have exposed significant overturning safety hazards under the eccentric loading of overloaded vehicles, raising serious concerns about the safety of existing bridges. Therefore, reinforcing existing single-column pier bridges has become an urgent task in the industry. How to scientifically and accurately assess the actual overturning resistance after reinforcement and ensure its operational safety has become a crucial and pressing technical challenge in the field of bridge engineering.

[0003] Currently, the conventional approach to evaluating the effectiveness of bridge reinforcement mainly relies on two methods. The first is to rely solely on theoretical calculations, which involves establishing a finite element model of the bridge, inputting design loads for simulation analysis, and determining whether the results meet the specifications. The second is to conduct traditional static load tests, typically involving loading vehicles onto the bridge deck and measuring the beam's deflection, strain, and other macroscopic responses. By comparing the measured values ​​with theoretical calculations, a qualitative assessment is made as to whether the bridge's overall stiffness and load-bearing capacity are normal. While these methods can reflect the overall working state of the structure to some extent, they generally lack specificity.

[0004] However, existing methods have significant drawbacks. Theoretical calculations cannot accurately reflect the actual stress state after reinforcement, and the calculation results may deviate from the actual safety. Traditional load tests mainly examine the vertical bearing capacity of bridges, but cannot accurately measure changes in support reactions, assess overturning safety, or effectively examine the working condition of the reinforced components themselves. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a test method for the anti-overturning performance of a single-column pier bridge after reinforcement, aiming to solve the above-mentioned problems described in the prior art.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A test method for the overturning resistance of a single-column pier bridge after reinforcement, the method comprising:

[0008] Obtain the structural parameters of the reinforced single-column pier bridge, generate a finite element model of the bridge including the reinforced structure based on the structural parameters, and simulate the bridge structural response under actual working conditions using the finite element model of the bridge.

[0009] Calculate the overturning stability coefficient of each section of the single-column pier bridge. Based on the overturning stability coefficient, determine the section and the reinforced pier section that control the most unfavorable overturning coefficient and mark them as test sections. Output the corresponding loading scheme and measuring instrument layout instructions.

[0010] Receive initialization data from the field measuring instruments. Once the measuring instruments are in normal condition, send a constant load lifting control command to the PLC lifting system to control the jacks to lift synchronously in stages. Receive force data from the pressure sensor in real time. When the force data is identified to be stable, calculate and store the sum of the force values ​​of each jack on the pier top as the constant load support force.

[0011] Send an off-center load distribution lifting command to the PLC lifting system to control the jacks to lift in stages according to a preset height, and simultaneously receive the lifting force and vertical displacement values ​​of each stage from the force sensor and displacement sensor to generate a support reaction force-displacement relationship curve and calculate the vertical stiffness value of the support.

[0012] Send graded eccentric loading commands to the loading control system, receive vertical displacement values ​​fed back by the dial gauge in real time, and calculate and store the eccentric load support reaction force in combination with the vertical stiffness value of the support.

[0013] Based on the influence line data of the maximum support reaction force of the reinforced pier, the loading vehicle layout data and jacking scheme instructions are generated and sent to the on-site control terminal. The structural response data fed back by the strain sensor and displacement sensor at the reinforced pier are received and stored simultaneously.

[0014] During the experiment, force data, displacement data and structural response data were analyzed in real time to dynamically predict the critical state of the bridge and provide feedback to adjust the jacking height or loading position.

[0015] After each adjustment, the support reaction force is recalculated. If the calculation result exceeds the preset tolerance, iterative optimization is triggered until the overturning stability coefficient converges to a stable value.

[0016] Based on the final verification data, the overturning resistance performance and reinforcement effect evaluation data of the reinforced single-column pier bridge are generated and output.

[0017] According to one aspect of the above technical solution, the step of generating a finite element model of a bridge including a reinforced structure based on the structural parameters includes:

[0018] The system calls a preset bridge component parameter library and automatically matches the material property parameters and geometric parameters of the reinforcement structure based on the bridge component parameter library.

[0019] Based on the structural parameters of the reinforced single-column pier bridge, the material properties and geometric parameters of the reinforced structure, a finite element model of the bridge is generated.

[0020] The structural parameters include bridge span, pier dimensions, and bearing type, while the material property parameters include the specifications of the reinforcement components and the material strength grade.

[0021] According to one aspect of the above technical solution, the step of outputting the measurement instrument arrangement instruction includes:

[0022] Based on the coordinate data of the top and bottom of the pier at the section with the most unfavorable overturning coefficient in the test section, as well as the steel cap beam, top and bottom of the pier at the reinforced pier section, the types and numbers of instruments to be placed at each location are automatically matched.

[0023] The measuring instrument is positioned and installed based on the coordinate data.

[0024] According to one aspect of the above technical solution, the constant load lifting control command sent to the PLC lifting system includes the lifting height parameter for each stage, the lifting speed parameter for each stage, and the pressure detection threshold.

[0025] Among them, by comparing multiple sets of force data fed back by the pressure sensor in real time, when the difference between any two adjacent sets of force data is less than the preset error threshold, it is determined that the pressure reading area is stable, and the corresponding calculation process of the constant load support reaction force is triggered.

[0026] According to one aspect of the above technical solution, the off-center load distribution lifting command sent to the PLC lifting system includes lifting height parameters for each level and lifting interval time parameters.

[0027] In generating the support reaction-displacement relationship curve, the least squares method is used to fit the collected lifting force value and vertical displacement value at each stage, and the slope of the curve is automatically calculated as the vertical stiffness value of the support.

[0028] According to one aspect of the above technical solution, the expression for calculating the reaction force at the eccentric support is: F = Δ × t;

[0029] Where F is the reaction force of the eccentric support, t is the vertical stiffness of the support, and Δ is the vertical displacement value fed back by the dial gauge when the eccentric load is applied.

[0030] According to one aspect of the above technical solution, the step of generating loading vehicle placement data based on the influence line data of the maximum support reaction force of the reinforced pier includes:

[0031] When obtaining the influence line data of the maximum support reaction force of the reinforced pier, the bridge finite element model is used to simulate the change of support reaction force under different loading positions;

[0032] Generate an influence line chart and automatically identify the loading position coordinates corresponding to the maximum value of the influence line of the reinforcement pier support reaction force, and convert the loading position coordinates into loading vehicle layout position data;

[0033] The loading vehicle placement data includes the number of loading vehicles, their spacing, and the parking lane number.

[0034] According to one aspect of the above technical solution, the following expression is used when performing support reaction calculation: 1.0R Gi +1.4R Qi >0;

[0035] Among them, R Gi For the reaction force of the dead load support, R Qi This is the reaction force at the eccentric support;

[0036] When performing the overturning stability coefficient verification, the stability effect ∑S is automatically calculated. bk,i With instability effect ∑S sk,i , where ∑S bk,i =∑R Gi ×l i ∑S represents the contribution of the support reaction force of the compression support to the moment under permanent action. sk,i =∑R Qi ×l i , representing the contribution of the support reaction force of the compression support to the moment under variable action, l i Let k be the center-to-center distance between the failed support and the effective support at the i-th pier. According to the expression k... qf =∑S bk,i / ∑S sk,i Calculate the overturning stability coefficient k qf Compare the output overturning stability coefficient k with the standard limit value. qf The verification results.

[0037] Compared with existing technologies, the test method for the overturning resistance of reinforced single-column pier bridges as shown in this invention has the following advantages:

[0038] The method described in this invention establishes a finite element model of the bridge, including the reinforced structure, for pre-simulation analysis, providing scientific theoretical guidance for field tests and effectively avoiding the blindness of traditional tests. Specifically, firstly, the key benchmark data of the dead load support reaction force is accurately obtained through synchronous jacking; then, the actual vertical stiffness of the support system is calibrated on-site using distributed jacking and least squares fitting techniques, converting the support reaction force, which is difficult to measure directly, into a displacement that is easy to measure accurately, greatly improving the convenience and reliability of data acquisition; finally, based on the influence line theory, the most unfavorable eccentric load is actively applied, and the strain and displacement response of the reinforced component are collected simultaneously. This deep integration of theoretical modeling, automated control, indirect measurement, and experimental testing not only enables accurate calculation of the overall overturning stability coefficient of the bridge but also allows for specific evaluation of the actual working state and reinforcement effect of the reinforced component itself, ultimately outputting overturning performance and reinforcement effect evaluation data. This provides crucial decision-making basis for the operational safety and subsequent maintenance of reinforced single-column pier bridges, possessing high engineering practical value and promotional significance. Attached Figure Description

[0039] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0040] Figure 1 This is a flowchart illustrating a test method for the anti-overturning performance of a single-column pier bridge after reinforcement, according to one embodiment of the present invention. Detailed Implementation

[0041] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0042] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0044] Example 1

[0045] Please see Figure 1 The first embodiment of the present invention provides a method for testing the overturning resistance of a single-column pier bridge after reinforcement, the method comprising steps S10-S90:

[0046] Step S10: Obtain the structural parameters of the reinforced single-column pier bridge, generate a finite element model of the bridge including the reinforced structure based on the structural parameters, and simulate the bridge structural response under actual working conditions using the finite element model of the bridge.

[0047] In this embodiment, the step of generating a finite element model of a bridge including a reinforced structure based on the structural parameters includes:

[0048] The system calls a preset bridge component parameter library and automatically matches the material property parameters and geometric parameters of the reinforcement structure based on the bridge component parameter library.

[0049] Based on the structural parameters of the reinforced single-column pier bridge, the material properties and geometric parameters of the reinforced structure, a finite element model of the bridge is generated.

[0050] The structural parameters include bridge span, pier dimensions, and bearing type, while the material property parameters include the specifications of the reinforcement components and the material strength grade.

[0051] Specifically, the structural parameters required include not only basic information such as the original span arrangement, dimensions, materials, and bearing types of the single-column pier bridge, but also specific parameters of the reinforcement measures adopted to improve overturning resistance. For example, if a single-column pier bridge is reinforced by adding a steel cap beam, then it is necessary to collect all parameters affecting structural stiffness, such as the steel type, cross-sectional geometry, and connection method between the steel cap beam and the original concrete pier.

[0052] More specifically, generating a finite element model of a bridge including the reinforced structure based on the above parameters is not simply superimposing the reinforced components onto the original bridge model. Instead, it involves accurately establishing the elements of the reinforced components and correctly simulating their mechanical connection with the original structure to obtain the bridge finite element model. Using the previous example, it is essential to ensure that the connection between the steel cap beam and the pier is set as a rigid connection capable of effectively transmitting bending moment and shear force. This ensures that the bridge finite element model can accurately reflect the actual impact of the reinforcement measures on the overall stiffness and load distribution path of the bridge.

[0053] Through pre-simulation analysis, it is possible to perform operations such as moving unit loads to calculate the influence lines of the support reactions of each pier, thereby accurately locating the most unfavorable loading position that causes the reinforced pier to bear the greatest force before the test. At the same time, the overturning stability coefficient of each section of the bridge can be preliminarily calculated, and the weak links and control sections of the structure can be identified in advance. The simulation results output at this time will be directly used to guide the deployment of measuring instruments and the formulation of loading schemes for subsequent field tests, ensuring that the field tests are carried out accurately and effectively controlling safety risks.

[0054] Step S20: Calculate the overturning stability coefficient of each section of the single-column pier bridge. Based on the overturning stability coefficient, determine the section with the most unfavorable overturning coefficient and the reinforced pier section and mark them as test sections. Output the corresponding loading scheme and measuring instrument layout instructions.

[0055] In this embodiment, the step of outputting the measurement instrument placement command includes:

[0056] Based on the coordinate data of the top and bottom of the pier at the section with the most unfavorable overturning coefficient in the test section, as well as the steel cap beam, top and bottom of the pier at the reinforced pier section, the types and numbers of instruments to be placed at each location are automatically matched.

[0057] The measuring instrument is positioned and installed based on the coordinate data.

[0058] Specifically, the calculations shown in this step are based on the bridge finite element model established in the previous steps. By simulating the load conditions required by the specifications, the overturning stability coefficient is automatically calculated for a series of potentially dangerous sections along the longitudinal direction of the bridge. Potentially dangerous sections include, for example, the centerline position of the support of each pier. The overturning stability coefficient is the most core quantitative indicator for measuring the bridge's ability to resist overturning. The lower the value, the higher the risk of overturning at that location.

[0059] In this process, the cross sections controlling the most unfavorable overturning coefficient and the reinforced pier cross sections were identified as test sections. The most unfavorable cross section refers to the cross section with the smallest stability coefficient value among all calculated cross sections. It represents the weakest link and safety control point of the entire bridge structure in terms of overturning resistance. The reinforced pier cross section is the object that needs to be specifically evaluated in this test. Regardless of whether its calculated coefficient is the smallest globally, it must be listed as a key monitoring object. These two types of cross sections are marked together as test sections, which constitute all the key measuring points of this test, ensuring that the test can not only evaluate the overall safety of the bridge, but also accurately verify the actual effect of the reinforcement measures.

[0060] Then, based on the determined test section locations, corresponding loading schemes and measuring instrument placement instructions are output. The loading scheme details the specific lanes, locations, and graded loading steps that the load should be placed in order to fully test these sections. The measuring instrument placement instructions will precisely indicate the types of sensors to be installed and their specific installation coordinates at key locations of each test section, providing clear operational guidance for on-site personnel and ensuring the smooth progress of test preparation and data acquisition.

[0061] Step S30: Receive initialization data from the field measuring instrument. Once the measuring instrument is in normal condition, send a constant load lifting control command to the PLC lifting system to control the jacks to lift synchronously in stages. Receive force data from the pressure sensor in real time. When the force data is identified as stabilizing, calculate and store the sum of the force values ​​of each jack on the pier top as the constant load support force.

[0062] In this embodiment, the constant load lifting control command sent to the PLC lifting system includes the lifting height parameter for each stage, the lifting speed parameter for each stage, and the pressure detection threshold.

[0063] Among them, by comparing multiple sets of force data fed back by the pressure sensor in real time, when the difference between any two adjacent sets of force data is less than the preset error threshold, it is determined that the pressure reading area is stable, and the corresponding calculation process of the constant load support reaction force is triggered.

[0064] Specifically, this step involves confirming the status of the on-site measuring instruments. Before sending any lifting command, initialization data is received from the on-site measuring instruments. The purpose of this initialization data is to confirm that all measuring instruments, such as pressure sensors and displacement gauges, are communicating normally and that their readings are zero. Only after all instruments are confirmed to be in normal condition will the subsequent lifting operation be initiated.

[0065] More specifically, a constant load lifting control command is sent to the PLC lifting system. This command is a precise set of parameters that specifies the lifting mode of the jacks as staged synchronous lifting. That is, the jacks on all piers move simultaneously at an extremely slow speed and in small steps to ensure that the bridge structure is lifted off the supports smoothly and evenly, avoiding secondary stress caused by asynchronous lifting, thereby realistically simulating the state in which the bridge's self-weight is lifted as a whole.

[0066] During the jacking process, the jacking status is determined by receiving force data from pressure sensors in real time. The key criterion is that the force data tends to stabilize. This means that the pressure reading is monitored after each jacking stage. When the change in the reading is less than a preset small threshold over a continuous period of time, it is considered that the bridge has been completely jacked off the supports, and the force on all jacks has been fully redistributed and reached a state of equilibrium. At this point, the entire dead load of the bridge is borne by the jacks.

[0067] Finally, by calculating and storing the sum of the jack force values ​​of each pier top as the dead load support force, at the instant the force value stabilizes, the pressure sensor readings of each jack on all pier tops are summed, and the resulting total force value is the total dead load of the bridge. This data serves as the source of stability effect when performing overturning verification in the subsequent process, and its accuracy directly affects the reliability of the final safety assessment.

[0068] Step S40: Send an off-center load distribution lifting command to the PLC lifting system to control the jacks to lift in stages according to a preset height, and simultaneously receive the lifting force and vertical displacement values ​​of each stage from the force sensor and displacement sensor, generate the support reaction force-displacement relationship curve and calculate the vertical stiffness value of the support.

[0069] In this embodiment, the off-center load distribution lifting command sent to the PLC lifting system includes the lifting height parameter for each stage and the lifting interval time parameter.

[0070] In generating the support reaction-displacement relationship curve, the least squares method is used to fit the collected lifting force value and vertical displacement value at each stage, and the slope of the curve is automatically calculated as the vertical stiffness value of the support.

[0071] Specifically, the execution of this step is fundamentally different from the synchronous jacking in step S30. By implementing the eccentric load condition distributed jacking, that is, the instruction is to jack up the jacks of a single or a specific group of piers in sequence and separately, the aim is to actively simulate the asymmetrical stress state of the bridge.

[0072] During the jacking process, the jacking force and vertical displacement values ​​at each stage are collected synchronously. For each pier being tested, the force sensor records the force applied by the jack, which is equivalent to the reaction force borne by the support, while the displacement sensor synchronously measures the actual vertical displacement generated at that point. A set of data points obtained from each stage of jacking is recorded, thus forming a series of discrete data points in the coordinate system.

[0073] In order to scientifically extract the characteristic values ​​representing the overall stiffness of the support from these discrete data, the least squares method is used to fit the above collected data in this embodiment. An optimal straight line is formed by fitting the data, so that the sum of the squares of the vertical distances of all data points to the line, i.e., the residuals, is minimized. The slope of the optimal fitted line is automatically calculated and determined as the vertical stiffness value of the support.

[0074] Step S50: Send a graded eccentric loading command to the loading control system, receive the vertical displacement value fed back by the dial gauge in real time, and calculate and store the eccentric load support reaction force in combination with the vertical stiffness value of the support.

[0075] In this embodiment, the expression for calculating the reaction force at the eccentric support is: F = Δ × t;

[0076] Where F is the reaction force of the eccentric support, t is the vertical stiffness of the support, and Δ is the vertical displacement value fed back by the dial gauge when the eccentric load is applied.

[0077] Specifically, the purpose of this step is to simulate the eccentric load conditions that the bridge may encounter in actual operation, and based on the support stiffness calibrated in step S40, to accurately measure the resulting change in support reaction force, providing key load effect data for the final overturning stability verification.

[0078] The graded eccentric loading command shown in this embodiment usually refers to controlling the loading vehicle to park and load in a graded and orderly manner on the bridge deck along one side of the lane according to a predetermined plan, so as to ensure that each load is accurately positioned and remains stable.

[0079] After each level of eccentric load is applied, the vertical displacement value fed back by the dial gauge is received in real time. The dial gauge is pre-installed on the support or beam near the test section determined in step S20 to monitor the minute vertical compression or deformation caused by the eccentric load, so as to reflect the amount of compression of the support under the eccentric load.

[0080] At this point, the reaction force increment F borne by the support under the current eccentric load can be calculated indirectly and quickly by multiplying the measured displacement change Δ by the known support stiffness t. That is, the eccentric load support reaction force.

[0081] Step S60: Based on the influence line data of the maximum support reaction force of the reinforced pier, generate the loading vehicle layout location data and jacking scheme instructions, and send them to the on-site control terminal accordingly. Simultaneously receive and store the structural response data fed back by the strain sensor and displacement sensor at the reinforced pier.

[0082] In this embodiment, the step of generating loading vehicle placement data based on the influence line data of the maximum support reaction force of the reinforced pier includes:

[0083] When obtaining the influence line data of the maximum support reaction force of the reinforced pier, the bridge finite element model is used to simulate the change of support reaction force under different loading positions;

[0084] Generate an influence line chart and automatically identify the loading position coordinates corresponding to the maximum value of the influence line of the reinforcement pier support reaction force, and convert the loading position coordinates into loading vehicle layout position data;

[0085] The loading vehicle placement data includes the number of loading vehicles, their spacing, and the parking lane number.

[0086] Specifically, this step is guided by the influence line data of the maximum support reaction force of the reinforced pier. The influence line clearly indicates the magnitude of the target reinforced pier's support reaction force when the load is at different locations on the bridge deck. Loading vehicle placement data is generated, explicitly instructing loading vehicles to be parked on the bridge deck lanes and at specific coordinates corresponding to the peak value of the influence line, ensuring maximum load effect. Simultaneously, coordinated jacking scheme instructions may be generated, such as instructing jacks at other pier locations to perform auxiliary jacking or adjust elevation to further increase the stress on the reinforced pier, thereby proactively creating a test condition close to the design limit.

[0087] The aforementioned precise jacking plan instructions are sent to the on-site control terminal to guide on-site personnel in arranging the most unfavorable load conditions. It should be noted that, unlike the support reaction force shown in step S50, the focus of synchronous monitoring in this step is the structural response data fed back by strain sensors and displacement sensors at the reinforced pier. This means that the measurement target has shifted from the support reaction force to the mechanical behavior of the reinforced structure itself. At this point, strain sensors are installed at key locations on the reinforced components, such as the lower flange at the mid-span of the steel cap beam and the pier-column connection, to measure their stress level under actual loads and determine whether it is within the elastic safety range.

[0088] By collecting and storing strain and displacement data under the most unfavorable working conditions, we can obtain state data of the working state of the reinforced structure. Based on this state data, we can evaluate the reinforcement effect of the single-column pier bridge and verify whether the reinforcement design has achieved the expected results and whether the structure is safe and reliable.

[0089] Step S70: During the test, the force data, displacement data and structural response data are analyzed in real time to dynamically predict the critical state of the bridge and provide feedback to adjust the jacking height or loading position.

[0090] In the method shown in this embodiment, step S70 is the core step, which aims to realize intelligent adaptive control of the test process. By analyzing real-time data, namely force data, displacement data and structural response data, and then dynamically adjusting the test process based on the real-time data, the accuracy and safety of the test are improved.

[0091] Specifically, taking the reinforcement project of a single-column pier on an elevated bridge in a certain city as an example, this bridge has typical structural characteristics of high piers and wide beam bottoms. Before the experiment, a finite element model was generated based on the corresponding structural parameters. After reinforcement, pressure sensors, displacement sensors, and strain sensors were deployed to collect corresponding force data, displacement data, and structural response data. The aforementioned force data, displacement data, and structural response data were transmitted to the backend in real time, and then real-time data analysis and adaptive control of the bridge test were performed based on the data.

[0092] Specifically, real-time data analysis and adaptive control of bridge tests are achieved through a machine learning model trained on historical test data. This model can identify various data patterns during the test, such as sudden jumps in force data or nonlinear increases in displacement data, thereby dynamically predicting the critical state of the bridge. For example, if the displacement rate exceeds a threshold, it is predicted that the bridge may be close to the risk of overturning.

[0093] Following the prediction, real-time feedback adjustments are triggered based on the prediction results, dynamically modifying the lifting height or the position of the loading vehicle via the PLC lifting system. For example, if the prediction indicates a critical risk, the lifting height is automatically reduced from 10mm to 5mm, or the loading vehicle position is adjusted to simulate a more unfavorable working condition while avoiding excessive risk.

[0094] After adaptive adjustment, the closed-loop verification stage will be entered, which aims to re-collect relevant data and verify it. Specifically, in this embodiment, it will proceed to step S80.

[0095] In step S80, after each adjustment, the support reaction force is recalculated. If the calculation result exceeds the preset tolerance, iterative optimization is triggered until the overturning stability coefficient converges to a stable value.

[0096] In this embodiment, the following expression is used when performing support reaction calculation: 1.0R Gi +1.4R Qi >0;

[0097] Among them, RGi For the reaction force of the dead load support, R Qi This is the reaction force at the eccentric support;

[0098] When performing the overturning stability coefficient verification, the stability effect ∑S is automatically calculated. bk,i With instability effect ∑S sk,i , where ∑S bk,i =∑R Gi ×l i ∑S represents the contribution of the support reaction force of the compression support to the moment under permanent action. sk,i =∑R Qi ×l i , representing the contribution of the support reaction force of the compression support to the moment under variable action, l i Let k be the center-to-center distance between the failed support and the effective support at the i-th pier. According to the expression k... qf =∑S bk,i / ∑S sk,i Calculate the overturning stability coefficient k qf Compare the output overturning stability coefficient k with the standard limit value. qf The verification results.

[0099] Specifically, in this embodiment, when performing data verification and effect evaluation, the support reaction force is first verified to check whether the support remains under compression under the most unfavorable load combination, thus avoiding the key premise of support detachment that leads to overturning.

[0100] The above support reaction calculation is performed using the following expression: 1.0 × R Gi +1.4×R Qi >0;

[0101] Among them, R Gi For the reaction force of the dead load support, R Qi The reaction force at the eccentrically loaded support is R. Gi The measured results from step S30 show that the eccentric support reaction force R Qi The calculation results from step S50. If the verification result is greater than zero, it indicates that the support has not detached under the basic load combination and meets the stability requirements.

[0102] Secondly, during data verification and effect evaluation, the overturning stability coefficient is verified. Based on the measured support reaction data, the stability effect ∑S around the overturning axis is automatically calculated. bk,i With instability effect ∑S sk,i .

[0103] The stabilization effect is mainly caused by the dead load, and the calculation formula is ∑S bk,i =∑R Gi ×l i In the formula, RGi For the dead load support reactions at each support, l i It is the center-to-center distance between the failed support and the effective support at the i-th pier, which is also the lever arm from the center of the support to the overturning axis.

[0104] The instability effect is mainly caused by eccentric live load, and the calculation formula is ∑S sk,i =∑R Qi ×l i , where R Qi This refers to the reaction force of the eccentrically loaded support, which is the live load reaction force of each support under the most unfavorable eccentrically loaded condition.

[0105] Step S90: Based on the final verification data, generate and output the overturning resistance performance and reinforcement effect evaluation data of the reinforced single-column pier bridge.

[0106] Specifically, according to expression k qf =∑S bk,i / ∑S sk,i Calculate the overturning stability coefficient k qf Compare this calculated value with the minimum safety limit specified in the bridge design code (such as k). qf By comparing with 2.5), quantitative verification results can be obtained, and evaluation data on the overturning resistance and reinforcement effect of the reinforced single-column pier bridge can be generated and output.

[0107] The above evaluation data not only includes the conclusions of whether the above verifications passed or failed, but also incorporates in-depth analysis of the structural response data of the reinforced piers in step S60. For example, even if the overall stability coefficient k... qf The requirements are met, but if the stress level of the reinforced component is too high or abnormal deformation occurs, the corresponding report of the assessment data can also indicate potential risks.

[0108] Compared with existing technologies, the test method for the overturning resistance of reinforced single-column pier bridges as shown in this invention has the following advantages:

[0109] The method described in this invention establishes a finite element model of the bridge, including the reinforced structure, for pre-simulation analysis, providing scientific theoretical guidance for field tests and effectively avoiding the blindness of traditional tests. Specifically, firstly, the key benchmark data of the dead load support reaction force is accurately obtained through synchronous jacking; then, the actual vertical stiffness of the support system is calibrated on-site using distributed jacking and least squares fitting techniques, converting the support reaction force, which is difficult to measure directly, into a displacement that is easy to measure accurately, greatly improving the convenience and reliability of data acquisition; finally, based on the influence line theory, the most unfavorable eccentric load is actively applied, and the strain and displacement response of the reinforced component are collected simultaneously. This deep integration of theoretical modeling, automated control, indirect measurement, and experimental testing not only enables accurate calculation of the overall overturning stability coefficient of the bridge but also allows for specific evaluation of the actual working state and reinforcement effect of the reinforced component itself, ultimately outputting overturning performance and reinforcement effect evaluation data. This provides crucial decision-making basis for the operational safety and subsequent maintenance of reinforced single-column pier bridges, possessing high engineering practical value and promotional significance.

[0110] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0111] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A test method for the overturning resistance performance of a single-column pier bridge after reinforcement, characterized in that, The method includes: Obtain the structural parameters of the reinforced single-column pier bridge, generate a finite element model of the bridge including the reinforced structure based on the structural parameters, and simulate the bridge structural response under actual working conditions using the finite element model of the bridge. Calculate the overturning stability coefficient of each section of the single-column pier bridge. Based on the overturning stability coefficient, determine the section and the reinforced pier section that control the most unfavorable overturning coefficient and mark them as test sections. Output the corresponding loading scheme and measuring instrument layout instructions. Receive initialization data from the field measuring instruments. Once the measuring instruments are in normal condition, send a constant load lifting control command to the PLC lifting system to control the jacks to lift synchronously in stages. Receive force data from the pressure sensor in real time. When the force data is identified to be stable, calculate and store the sum of the force values ​​of each jack on the pier top as the constant load support force. Send an off-center load distribution lifting command to the PLC lifting system to control the jacks to lift in stages according to a preset height, and simultaneously receive the lifting force and vertical displacement values ​​of each stage from the force sensor and displacement sensor to generate a support reaction force-displacement relationship curve and calculate the vertical stiffness value of the support. Send graded eccentric loading commands to the loading control system, receive vertical displacement values ​​fed back by the dial gauge in real time, and calculate and store the eccentric load support reaction force in combination with the vertical stiffness value of the support. Based on the influence line data of the maximum support reaction force of the reinforced pier, the loading vehicle layout data and jacking scheme instructions are generated and sent to the on-site control terminal. The structural response data fed back by the strain sensor and displacement sensor at the reinforced pier are received and stored simultaneously. During the experiment, force data, displacement data and structural response data were analyzed in real time to dynamically predict the critical state of the bridge and provide feedback to adjust the jacking height or loading position. After each adjustment, the support reaction force is recalculated. If the calculation result exceeds the preset tolerance, iterative optimization is triggered until the overturning stability coefficient converges to a stable value. Based on the final verification data, the overturning resistance performance and reinforcement effect evaluation data of the reinforced single-column pier bridge are generated and output.

2. The test method for the overturning resistance of a single-column pier bridge after reinforcement according to claim 1, characterized in that, The steps for generating a finite element model of a bridge including a reinforced structure based on the structural parameters include: The system calls a preset bridge component parameter library and automatically matches the material property parameters and geometric parameters of the reinforcement structure based on the bridge component parameter library. Based on the structural parameters of the reinforced single-column pier bridge, the material properties and geometric parameters of the reinforced structure, a finite element model of the bridge is generated. The structural parameters include bridge span, pier dimensions, and bearing type, while the material property parameters include the specifications of the reinforcement components and the material strength grade.

3. The test method for the overturning resistance of a single-column pier bridge after reinforcement according to claim 1, characterized in that, The steps for outputting measurement instrument placement instructions include: Based on the coordinate data of the top and bottom of the pier at the section with the most unfavorable overturning coefficient in the test section, as well as the steel cap beam, top and bottom of the pier at the reinforced pier section, the types and numbers of instruments to be placed at each location are automatically matched. The measuring instrument is positioned and installed based on the coordinate data.

4. The test method for the overturning resistance of a single-column pier bridge after reinforcement according to claim 1, characterized in that, The constant load lifting control commands sent to the PLC lifting system include lifting height parameters for each stage, lifting speed parameters for each stage, and pressure detection thresholds. Among them, by comparing multiple sets of force data fed back by the pressure sensor in real time, when the difference between any two adjacent sets of force data is less than the preset error threshold, it is determined that the pressure reading area is stable, and the corresponding calculation process of the constant load support reaction force is triggered.

5. The test method for the overturning resistance of a single-column pier bridge after reinforcement according to claim 1, characterized in that, The off-center load distribution lifting command sent to the PLC lifting system includes the lifting height parameter for each stage and the lifting interval time parameter; In generating the support reaction-displacement relationship curve, the least squares method is used to fit the collected lifting force value and vertical displacement value at each stage, and the slope of the curve is automatically calculated as the vertical stiffness value of the support.

6. The test method for the overturning resistance of a single-column pier bridge after reinforcement according to claim 1, characterized in that, The expression for calculating the reaction force at the eccentric support is: F = Δ × t; Where F is the reaction force of the eccentric support, t is the vertical stiffness of the support, and Δ is the vertical displacement value fed back by the dial gauge when the eccentric load is applied.

7. The test method for the overturning resistance of a single-column pier bridge after reinforcement according to claim 1, characterized in that, The steps for generating loading vehicle placement data based on the influence line data of the maximum support reaction force of the reinforced pier include: When obtaining the influence line data of the maximum support reaction force of the reinforced pier, the bridge finite element model is used to simulate the change of support reaction force under different loading positions; Generate an influence line chart and automatically identify the loading position coordinates corresponding to the maximum value of the influence line of the reinforcement pier support reaction force, and convert the loading position coordinates into loading vehicle layout position data; The loading vehicle placement data includes the number of loading vehicles, their spacing, and the parking lane number.

8. The test method for the overturning resistance of a single-column pier bridge after reinforcement according to any one of claims 1-7, characterized in that, When performing support reaction calculations, the following expression is used: 1.0R Gi +1.4R Qi >0; Among them, R Gi For the reaction force of the dead load support, R Qi This is the reaction force at the eccentric support; When performing the overturning stability coefficient verification, the stability effect ∑S is automatically calculated. bk,i With instability effect ∑S sk,i , where ∑S bk,i =∑R Gi ×l i ∑S represents the contribution of the support reaction force of the compression support to the moment under permanent action. sk,i =∑R Qi ×l i , representing the contribution of the support reaction force of the compression support to the moment under variable action, l i Let k be the center-to-center distance between the failed support and the effective support at the i-th pier. According to the expression k... qf =∑S bk,i / ∑S sk,i Calculate the overturning stability coefficient k qf Compare the output overturning stability coefficient k with the standard limit value. qf The verification results.

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