Bridge steel structure deflection detection device and detection method

Abstract

The invention discloses a bridge steel structure deflection detection device and detection method, and relates to the technical field of deflection detection. Comprising the following steps: selecting a plurality of specified points on a bridge steel structure, and measuring and recording inclination angle values of the points by using an inclinometer; based on the collected multiple dip angle values, a least square method is adopted to fit a dip angle function f (x), and x is the transverse or longitudinal position of the bridge; according to a direct integration algorithm, integration is carried out on the inclination angle function f (x) in the interval (a, b) where the to-be-measured point is located, and a deflection value I of the to-be-measured point is obtained. By using the inclinometer and the least square fitting, the deflection of the bridge structure can be accurately calculated, the data can be recorded and analyzed in real time, potential structure problems can be timely found, the deflection condition of each point can be comprehensively considered through the integration algorithm, more comprehensive structure health assessment is provided, analysis is performed by using the inclinometer data, and the accuracy of the structure health assessment is improved. Dependence on traditional physical measurement is reduced, and reliability and efficiency of detection are improved.

Description

Technical Field

[0001] The invention relates to the technical field of deflection detection, and in particular to a bridge steel structure deflection detection device and a detection method. Background Art

[0002] Bridge deflection is a very important parameter for bridge structures. It directly reflects the vertical overall stiffness of the bridge structure and is an important basis for reflecting the linear changes of the bridge. Bridge deflection is closely related to the bridge's bearing capacity and its ability to withstand dynamic loads such as earthquakes. Scientific testing methods are not only of great significance for the testing of bridge bearing capacity and bridge earthquake prevention and disaster reduction, but also can accumulate practical experience for improving bridge design theory and construction technology.

[0003] Bridge deflection is an important parameter to measure the health status of bridge structure and is of great significance for ensuring the safe operation of bridges. Traditional bridge deflection detection methods such as dial indicator measurement method and leveling measurement method have shortcomings such as cumbersome operation, long time consumption and environmental restrictions. Especially for large and complex bridges, traditional methods are difficult to meet the high-precision and high-efficiency detection needs. Summary of the invention

[0004] The purpose of the present invention is to provide a bridge steel structure deflection detection device and detection method to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a bridge steel structure deflection detection method, characterized in that it includes:

[0006] Select multiple designated points on the bridge steel structure, use an inclinometer to measure and record the inclination values ​​of these points;

[0007] Based on the collected multiple inclination values, a least square method is used to fit an inclination function f(x), where x is the lateral or longitudinal position of the bridge;

[0008] According to the direct integration algorithm, the inclination function f(x) is integrated over the interval (a, b) where the test point is located to obtain the disturbance value I of the test point.

[0009] As a specific solution of the technical method of this application,

[0010] The method comprises selecting a plurality of designated points on the bridge steel structure, using an inclinometer to measure and record the inclination values ​​of these points, including:

[0011] According to the structural characteristics and inspection requirements of the bridge, multiple designated points are selected on the steel structure of the bridge, and the designated points are distributed at different positions of the bridge;

[0012] At each selected designated point, an inclinometer is installed and fixed on the steel structure of the bridge to ensure the stability and accuracy of the measurement results;

[0013] Start the inclinometer, start measuring and record the inclination value of each specified point. The inclinometer displays the inclination value of the current measuring point in real time. The data is expressed in degrees or radians to obtain the inclination value.

[0014] Record the measured inclination values ​​and indicate the location and measurement time of each measurement point;

[0015] Multiple measurements are taken at the same set of designated points in different time periods, and the changing trend and stability of the bridge deflection are evaluated by comparing the measurement results in different time periods.

[0016] As a specific solution of the technical method of this application,

[0017] The method of fitting an inclination function f(x) based on the collected multiple inclination values ​​by the least square method, where x is the lateral or longitudinal position of the bridge, includes:

[0018] Determine the lateral or longitudinal position x of the bridge in the dataset i and the corresponding inclination value y i ;

[0019] Select the model type and choose the appropriate model type based on data characteristics and prior knowledge;

[0020] Establish an objective function and define an objective function, usually the minimum sum of squares of errors. For a linear model, the objective function is Where a and b are model parameters;

[0021] For linear models, the design matrix X usually consists of the position values ​​x i and the constant 1

[0022] As a specific solution of the technical method of this application,

[0023] The method of fitting an inclination function f(x) based on the collected multiple inclination values ​​by using the least square method, wherein x is the lateral or longitudinal position of the bridge, further includes:

[0024] Using the least squares method to solve the parameters, for the linear model, the parameters a and b can be solved by the following formula (a, b) = (X T X) -1 X T Y, where X T is the transpose of X, and Y is the vector of inclination values;

[0025] Calculate the fitting function, substitute the obtained parameters a and b into the model equation, and obtain the fitting function y=ax+b;

[0026] Evaluate the fitting results and calculate the residual sum of squares RSS and the coefficient of determination R 2 To evaluate the fitting effect Where TSS is the total sum of squares

[0027] Conduct model diagnostics to check for outliers, leverage points, and other factors that may affect model fit;

[0028] Use the fitted model for prediction or further analysis.

[0029] As a specific solution of the technical method of this application,

[0030] According to the direct integration algorithm, the inclination function f(x) is integrated over the interval (a, b) where the test point is located to obtain the disturbance value I of the test point, including:

[0031] Determine the interval [a,b] where the point to be tested is located;

[0032] Select appropriate numerical integration methods according to the characteristics of the problem, including trapezoidal rule, Simpson's rule and Gauss-Legend integral;

[0033] Divide the interval [a,b] into n small intervals, the width of each small interval is

[0034] The integral sum of each cell is calculated according to the selected numerical integration method, using the trapezoidal rule, and the formula is where x i =a+iΔx;

[0035] Substitute the calculated integral sum into the numerical integration formula to obtain the approximate integral value of the entire interval.

[0036] As a specific solution of the technical method of this application,

[0037] The method integrates the inclination function f(x) in the interval (a, b) where the test point is located according to the direct integration algorithm to obtain the disturbance value I of the test point, and also includes:

[0038] Evaluate the error of numerical integration by increasing the number of interval divisions n and comparing the integral results for different values ​​of n;

[0039] If the precision of the integral result is not enough, use a higher-order numerical integration method;

[0040] The obtained integral result is used to actually calculate the deflection value of the bridge.

[0041] As a specific solution of the technical method of this application,

[0042] If the precision of the integral result is not enough, use a higher-order numerical integration method, including:

[0043] Increasing the number of intervals n can improve the accuracy of the integral. For the trapezoidal rule and Simpson's rule, increasing n usually reduces the error between each small area, thereby reducing the overall error.

[0044] Dynamically adjust the size of the intervals based on the rate of change of the function in different intervals, using finer divisions where the function changes in size and coarser divisions where the change is small;

[0045] During the integration process, an error estimate is calculated at the same time. If the error exceeds a predetermined threshold, the number of divisions of the interval can be automatically increased;

[0046] For some numerical integration methods, the accuracy is improved by Richardson extrapolation, computing the integral results for different n and then using these results to evaluate higher-order approximations;

[0047] The accuracy can also be improved by changing the starting and ending points of the integration interval to reduce the influence of singular points or discontinuities in the integration.

[0048] For some complex functions that are difficult to integrate deterministically, Monte Carlo methods are used to evaluate the value of the integral by random sampling.

[0049] A bridge steel structure deflection detection device, which uses the bridge steel structure deflection detection method described in any of claims 1-7.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The bridge steel structure deflection detection device and detection method can accurately calculate the disturbance of the bridge structure by using an inclinometer and least squares fitting, and can record and analyze data in real time, which is helpful to timely discover potential structural problems. Through the integral algorithm, the disturbance conditions of each point can be comprehensively considered to provide a more comprehensive structural health assessment. The inclinometer data is used for analysis, which reduces the dependence on traditional physical measurements and improves the reliability and efficiency of detection.

[0052] At the same time, the least squares method can effectively improve the accuracy of the fitting function by optimizing the sum of squared errors. It can select the appropriate model type according to the data characteristics and adapt to different bridge structures. Evaluation indicators such as the residual sum of squares and the coefficient of determination help to accurately measure the model fitting effect. The model diagnosis step can identify and process outliers and leverage points to ensure the reliability of the fitting results. The fitted model can be used to predict future slope changes and provide data support for bridge maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A schematic diagram of a bridge steel structure strength detection method according to the present invention;

[0054] Figure 2 It is a schematic diagram of the inclination function fitting of a deflection detection method of a bridge steel structure of the present invention;

[0055] Figure 3 A disturbance calculation schematic diagram of a disturbance detection method for a bridge steel structure of the present invention; DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] like Figure 1-Figure 3 As shown, the present invention provides a technical solution: a bridge steel structure deflection detection method, characterized in that it includes:

[0058] Select multiple designated points on the bridge steel structure, use an inclinometer to measure and record the inclination values ​​of these points;

[0059] Based on the collected multiple inclination values, a least square method is used to fit an inclination function f(x), where x is the lateral or longitudinal position of the bridge;

[0060] According to the direct integration algorithm, the inclination function f(x) is integrated over the interval (a, b) where the test point is located to obtain the disturbance value I of the test point.

[0061] Select multiple designated points on the bridge steel structure and use an inclinometer to measure and record the inclination values ​​of these points, including:

[0062] According to the structural characteristics and inspection requirements of the bridge, multiple designated points are selected on the steel structure of the bridge. The designated points are distributed at different positions of the bridge, including support points and mid-span points;

[0063] Install an inclinometer at each selected designated point. The inclinometer is fixed on the steel structure of the bridge to ensure the stability and accuracy of the measurement results. Connect the inclinometer to the data transmission system to ensure that the connection is stable and reliable, and there is no delay or loss in data transmission. According to monitoring requirements, set the parameters of the data acquisition system, such as sampling frequency, storage interval and data format. Clean the surface of the inclinometer and the data transmission system regularly to prevent dust and rain from affecting its normal operation. When necessary, install a protective cover for the inclinometer to improve its environmental resistance and service life;

[0064] Start the inclinometer, start measuring and record the inclination value of each specified point. The inclinometer displays the inclination value of the current measuring point in real time. The data is expressed in degrees or radians. After obtaining the inclination value, set the measurement coefficient through the inclinometer control panel or remote control system, including selecting the measurement unit and setting the sampling frequency. Configure the data transmission method to ensure that all settings meet the specific needs and specifications of bridge monitoring. The inclinometer should be equipped with a data storage function that can automatically record the inclination value of each measurement and can transmit the data to a remote computer or data center for analysis and storage;

[0065] Record the measured inclination values ​​and indicate the location and measurement time of each measurement point. Assign a unique identifier to each measurement point and clearly mark it when recording. Arrange and classify the collected measurement data according to the location and time sequence of the measurement points.

[0066] Conduct multiple measurements at the same set of designated points in different time periods, and evaluate the changing trend and stability of bridge disturbance by comparing the measurement results of different time periods. Analyze the changing trend of bridge disturbance by comparing the measurement results of the same set of designated points in different time periods. Evaluate the stability of the bridge based on the results of trend analysis. When evaluating bridge stability, eliminate interference factors or make corresponding corrections as much as possible. Comparing and verifying the measurement results with bridge design parameters, historical monitoring data or theoretical models will help confirm the accuracy and reliability of the measurement results and identify potential problems or improvements.

[0067] Based on the collected multiple inclination values, the least square method is used to fit an inclination function f(x), where x is the lateral or longitudinal position of the bridge, including:

[0068] Determine the lateral or longitudinal position x of the bridge in the dataset i and the corresponding inclination value y i ;

[0069] Select the model type and choose the appropriate model type based on data characteristics and prior knowledge;

[0070] Establish an objective function and define an objective function, usually the minimum sum of squares of errors. For a linear model, the objective function is Where a and b are model parameters;

[0071] For linear models, the design matrix X usually consists of the position values ​​x i and the constant 1

[0072] Based on the collected multiple inclination values, the least square method is used to fit an inclination function f(x), where x is the lateral or longitudinal position of the bridge, and also includes:

[0073] Using the least squares method to solve the parameters, for the linear model, the parameters a and b can be solved by the following formula (a, b) = (X T X) -1 X T Y, where X T is the transpose of X, and Y is the vector of inclination values;

[0074] Calculate the fitting function, substitute the obtained parameters a and b into the model equation, and obtain the fitting function y=ax+b;

[0075] Evaluate the fitting results and calculate the residual sum of squares RSS and the coefficient of determination R 2 To evaluate the fitting effect Where TSS is the total sum of squares

[0076] Conduct model diagnosis to check whether there are outliers, leverage points and other factors that may affect model fit, which can be done through residual analysis and leverage point detection;

[0077] Use the fitted model for prediction or further analysis, analyze the calculated disturbance values, evaluate the disturbance of the bridge, and perform subsequent maintenance and adjustments as needed.

[0078] According to the direct integration algorithm, the inclination function f(x) is integrated over the interval (a, b) where the test point is located to obtain the disturbance value I of the test point, including:

[0079] Determine the interval [a,b] where the point to be tested is located;

[0080] Select appropriate numerical integration methods according to the characteristics of the problem, including trapezoidal rule, Simpson's rule and Gauss-Legend integral;

[0081] Divide the interval [a,b] into n small intervals, the width of each small interval is

[0082] The integral sum of each cell is calculated according to the selected numerical integration method, using the trapezoidal rule, and the formula is where x i=a+iΔx;

[0083] Substitute the calculated integral sum into the numerical integration formula to obtain the approximate integral value of the entire interval.

[0084] According to the direct integration algorithm, the inclination function f(x) is integrated over the interval (a, b) where the test point is located to obtain the disturbance value I of the test point, which also includes:

[0085] Evaluate the error of numerical integration by increasing the number of interval divisions n and comparing the integral results for different values ​​of n;

[0086] If the precision of the integral result is not enough, use a higher-order numerical integration method;

[0087] The obtained integral result is used to actually calculate the deflection value of the bridge.

[0088] If the precision of the integral result is not enough, use higher-order numerical integration methods, including:

[0089] Increasing the number of intervals n can improve the accuracy of the integral. For the trapezoidal rule and Simpson's rule, increasing n usually reduces the error between each small area, thereby reducing the overall error.

[0090] Dynamically adjust the size of the intervals based on the rate of change of the function in different intervals, using finer divisions where the function changes in size and coarser divisions where the change is small;

[0091] During the integration process, an error estimate is calculated at the same time. If the error exceeds a predetermined threshold, the number of divisions of the interval can be automatically increased;

[0092] For some numerical integration methods, accuracy is improved by Richardson extrapolation, computing the integral results for different n and then using these results to evaluate higher-order approximations;

[0093] The accuracy can also be improved by changing the starting and ending points of the integration interval to reduce the influence of singular points or discontinuities in the integration.

[0094] For some complex functions that are difficult to integrate deterministically, Monte Carlo methods are used to evaluate the value of the integral by random sampling.

[0095] A bridge steel structure deflection detection device uses any bridge steel structure deflection detection method according to claims 1-7.

[0096] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is limited by the attached embodiments and their equivalents.

Claims

1. A method for detecting deflection of a bridge steel structure, characterized in that: include: Select multiple designated points on the bridge steel structure, use an inclinometer to measure and record the inclination values ​​of these points; Based on the collected multiple inclination values, a least square method is used to fit an inclination function f(x), where x is the lateral or longitudinal position of the bridge; According to the direct integration algorithm, the inclination function f(x) is integrated over the interval (a, b) where the test point is located to obtain the disturbance value I of the test point.

2. A bridge steel structure deflection detection method according to claim 1, characterized in that: The method comprises selecting a plurality of designated points on the bridge steel structure, using an inclinometer to measure and record the inclination values ​​of these points, including: According to the structural characteristics and inspection requirements of the bridge, multiple designated points are selected on the steel structure of the bridge, and the designated points are distributed at different positions of the bridge; At each selected designated point, an inclinometer is installed and fixed on the steel structure of the bridge to ensure the stability and accuracy of the measurement results; Start the inclinometer, start measuring and record the inclination value of each specified point. The inclinometer displays the inclination value of the current measuring point in real time. The data is expressed in degrees or radians to obtain the inclination value. Record the measured inclination values ​​and indicate the location and measurement time of each measurement point; Multiple measurements are taken at the same set of designated points in different time periods, and the changing trend and stability of the bridge deflection are evaluated by comparing the measurement results in different time periods.

3. A bridge steel structure deflection detection method according to claim 1, characterized in that: The method of fitting an inclination function f(x) based on the collected multiple inclination values ​​by the least square method, where x is the lateral or longitudinal position of the bridge, includes: Determine the lateral or longitudinal position x of the bridge in the dataset i and the corresponding inclination value y i ; Select the model type and choose the appropriate model type based on data characteristics and prior knowledge; Establish an objective function and define an objective function, usually the minimum sum of squares of errors. For a linear model, the objective function is Where a and b are model parameters; For linear models, the design matrix X usually consists of the position values ​​x i and the constant 1 4. A bridge steel structure deflection detection method according to claim 1, characterized in that: The method of fitting an inclination function f(x) based on the collected multiple inclination values ​​by using the least square method, wherein x is the lateral or longitudinal position of the bridge, further includes: Using the least squares method to solve the parameters, for the linear model, the parameters a and b can be solved by the following formula (a, b) = (X T X) -1 X T Y, where X T is the transpose of X, and Y is the vector of inclination values; Calculate the fitting function, substitute the obtained parameters a and b into the model equation, and obtain the fitting function y=ax+b; Evaluate the fitting results and calculate the residual sum of squares RSS and the coefficient of determination R 2 To evaluate the fitting effect Where TSS is the total sum of squares Perform model diagnostics to check for outliers, leverage points, and other factors that may affect model fit; Use the fitted model for prediction or further analysis.

5. A bridge steel structure deflection detection method according to claim 1, characterized in that: According to the direct integration algorithm, the inclination function f(x) is integrated over the interval (a, b) where the test point is located to obtain the disturbance value I of the test point, including: Determine the interval [a,b] where the point to be tested is located; Select appropriate numerical integration methods according to the characteristics of the problem. Numerical integration methods include trapezoidal rule, Simpson's rule and Gauss-Legend integral; Divide the interval [a,b] into n small intervals, the width of each small interval is The integral sum of each cell is calculated according to the selected numerical integration method, using the trapezoidal rule, and the formula is where x i =a+iΔx; Substitute the calculated integral sum into the numerical integration formula to obtain the approximate integral value of the entire interval.

6. A bridge steel structure deflection detection method according to claim 1, characterized in that: The method integrates the inclination function f(x) in the interval (a, b) where the test point is located according to the direct integration algorithm to obtain the disturbance value I of the test point, and also includes: Evaluate the error of numerical integration by increasing the number of interval divisions n and comparing the integral results for different values ​​of n; If the precision of the integral result is not enough, use a higher-order numerical integration method; The obtained integral result is used to actually calculate the deflection value of the bridge.

7. A bridge steel structure deflection detection method according to claim 6, characterized in that: If the precision of the integral result is not enough, use a higher-order numerical integration method, including: Increasing the number of intervals n can improve the accuracy of the integral. For the trapezoidal rule and Simpson's rule, increasing n usually reduces the error between each small area, thereby reducing the overall error. Dynamically adjust the size of the intervals based on the rate of change of the function in different intervals, using finer divisions where the function changes in size and coarser divisions where the change is small; During the integration process, an error estimate is calculated at the same time. If the error exceeds a predetermined threshold, the number of divisions of the interval can be automatically increased; For some numerical integration methods, the accuracy is improved by Richardson extrapolation, computing the integral results for different n and then using these results to evaluate higher-order approximations; The accuracy can also be improved by changing the starting and ending points of the integration interval to reduce the influence of singular points or discontinuities in the integration. For some complex functions that are difficult to integrate deterministically, Monte Carlo methods are used to evaluate the value of the integral by random sampling.

8. A bridge steel structure deflection detection device, characterized in that: The bridge steel structure deflection detection method described in any of claims 1-7 is used.

Images