A tied arch bridge suspender replacement construction bridge elevation active control method and system

Abstract

The present application relates to a construction technology of replacing a suspender, in particular to a method and system for actively controlling the elevation of a bridge deck during the construction of replacing a suspender of a tied-arch bridge. The method is based on establishing an optimization equation of the cable force factor, the temperature gradient of the tie beam cross section and the theoretical value of the control point elevation, and then solving the theoretical value of the cable force factor and the temperature gradient of the tie beam cross section under each working condition. A Bayesian network model is constructed with the replacement suspender cable force deviation, the temporary suspender cable force deviation, the adjacent suspender cable force deviation and the tie beam cross section temperature gradient deviation as the root nodes, and the control point relative elevation deviation as the leaf node. During the replacement of the suspender, the feedback information is converted into dimensionless deviation data, and the reasoning of the Bayesian network is realized. The present application uses a liftable laser measuring instrument to measure the elevation, and realizes the synchronous lifting and lowering of the bridge deck through the bridge deck sling device, which has high precision and high timeliness, and avoids the errors caused by manual control methods.

Description

Technical Field

[0001] This invention relates to the construction technology of suspender replacement, and in particular to a method and system for actively controlling the bridge deck elevation during suspender replacement construction of tied arch bridges. Background Technology

[0002] With the continuous development of the economy and society, the total volume of transportation is increasing, and the problem of vehicle overloading is becoming increasingly prominent. Coupled with numerous factors such as design and construction defects, improper operation and maintenance, and material degradation in tied-arch bridges, structural safety hazards caused by hanger defects such as broken steel strands, corrosion, and fatigue are gradually being exposed. Currently, many tied-arch bridges in service in my country are operating with defects and face the problem of hanger replacement.

[0003] Structural alignment changes are one of the most important feedback indicators in construction control. For the replacement of hangers on tied arch bridges, as the construction progresses through different stages, changes in hanger cable tension and structural internal forces lead to changes in the bridge deck alignment and arch rib displacement. The bridge deck alignment directly affects the pavement performance; excessive alignment changes can cause pavement cracking, further impacting the bridge's driving comfort and safety, and even causing damage to the bridge deck system. The relative elevation change of the bridge deck outside each replaced hanger is a direct reflection of the bridge deck alignment changes during construction. Therefore, it is necessary to keep the relative elevation change of the bridge deck outside the replaced hangers within a controllable range to ensure that the final bridge alignment meets the requirements.

[0004] The common method for controlling bridge deck alignment during suspender replacement construction relies primarily on engineering experience to set the amplitude of bridge deck elevation changes, which are then manually monitored to ensure the changes do not exceed the preset range. However, this construction control method lacks flexibility; the manually observed bridge deck elevation data always lags behind the actual development of the bridge deck alignment, making it difficult to control the bridge deck elevation in real time and accurately during construction, thus reducing construction quality and efficiency. Therefore, it is necessary to combine theoretical calculations and measured data to analyze the changing trends of the bridge deck alignment during suspender replacement construction, thereby improving the real-time performance and accuracy of bridge deck elevation control. Summary of the Invention

[0005] Technical issues:

[0006] Objective of the Invention: To address the aforementioned problems, this invention provides a method and system for actively controlling the bridge deck elevation during the replacement of hangers in a tied-arch bridge. This invention enables proactive control of the bridge deck elevation during hanger replacement, ensuring the structural safety and rational alignment of the structure in real time and effectively.

[0007] Technical solution: To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0008] A method for actively controlling the bridge deck elevation during the replacement of hangers in a tied-arch bridge, characterized by the following control method:

[0009] Step 1: Install the bridge deck hoisting device at the location of the replaced suspender on the tied arch bridge, spanning the crossbeams of two adjacent suspenders of the replaced suspender; define the connection point between the replaced suspender and the bridge deck as the control point, and use the elevation change of the control point as the feedback indicator of the bridge deck elevation change;

[0010] Reflective targets were placed at the control points and calibrated using a laser measuring instrument to determine the initial elevation P0 of the control points and obtain the control point elevation data for subsequent construction processes.

[0011] Cable force gauges were installed on the replaced suspender, the adjacent suspender, and the bridge deck hoisting device to obtain the measured values ​​of the cable force of the replaced suspender, the cable force of the adjacent suspender, and the cable force of the temporary suspender.

[0012] Thermometers were installed on the surface of the tie beam near the control point to obtain the measured temperature gradient of the tie beam section.

[0013] Step 2: The replacement of the boom requires n working conditions. When the boom replacement reaches working condition i (i = 1, 2, 3, ..., n), the theoretical value of the control point elevation for each working condition is P. i Establish theoretical values ​​P for the cable forces of the replaced hanger, temporary hanger, adjacent hanger, temperature gradient of the tie beam section, and control point elevation. i The optimization equation;

[0014] P i -P i-1 =δ i T i +δ l i T l i +δ x i T x i +δ c i C i = f(T) + g(C)

[0015] Where δi is the influence of the change in vertical displacement of the control point caused by the unit change in the cable force of the replaced boom under each working condition;

[0016] Ti represents the theoretical value of the cable force of the replaced boom under each working condition;

[0017] This refers to the effect of a unit change in the temporary suspender cable force under various working conditions on the vertical displacement of the control point.

[0018] These are the theoretical values ​​of the temporary suspender cable force under various working conditions;

[0019] This represents the influence of a unit change in the cable force of adjacent booms under various working conditions on the vertical displacement of the control point.

[0020] These are the theoretical values ​​of the cable force of adjacent suspenders under each working condition;

[0021] This represents the influence of a unit change in the temperature gradient of the beam section under various working conditions on the vertical displacement of the control points.

[0022] C i The theoretical values ​​of the temperature gradient of the beam section under various working conditions;

[0023] f(T) is about Ti, The function;

[0024] g(C) is about C i The function;

[0025] The theoretical values ​​of the cable force of the replaced hanger, the temporary hanger, the adjacent hanger, and the temperature gradient of the tie beam section are obtained by optimizing the objective function as follows:

[0026]

[0027] Step 3: Based on the measured and theoretical values ​​obtained in Steps 1 and 2, use the following formula:

[0028] (Measured value - Theoretical value) / Theoretical value

[0029] The following parameters were calculated: cable force deviation of the replaced hanger x1, cable force deviation of the temporary hanger x2, cable force deviation of adjacent hangers x3, temperature gradient deviation of the tie beam section x4, and relative elevation deviation of the control point y. p ;

[0030] Step 4: Using the cable force deviation of the replaced suspender x1, the cable force deviation of the temporary suspender x2, the cable force deviation of the adjacent suspender x3, and the temperature gradient deviation of the tie beam section x4 as root node variables, control the relative elevation deviation y of the control point. p Construct a Bayesian network model for the leaf node variables;

[0031] Given the prior: the mean of the root node variables is 0, and the variances are 9%, 12%, 6%, and 40%, respectively; based on the optimization equation in step two, 10 are sampled using MC sampling. 5 1 sample point as the initial sample;

[0032] Step 5: Copy the deviation data obtained in Step 3 10 times. 5 This sample is used as evidence and added to the initial sample in step four to form a training sample, which is used to train the Bayesian network model, thereby obtaining the predicted elevation value P of the control point for each working condition. *i ;

[0033] Step Six: Using the P obtained in Step Five * i As the target value for the elevation of each control point under various operating conditions, the ray point of the laser measuring instrument is controlled in advance at an elevation of P. * i The bridge deck is raised or lowered by adjusting the tension of each jack, and the laser measuring instrument is observed until the reflective target and the laser measuring instrument are successfully calibrated, thus realizing active control of the bridge deck elevation during the replacement of the suspenders.

[0034] The control system used in the active control method for bridge deck elevation during tie-arch bridge suspender replacement construction as described in this invention includes a data processing subsystem and an active control subsystem. The data processing subsystem is mainly used to collect data on the cable force deviation x1 of the suspender being replaced, the cable force deviation x2 of the temporary suspender, the cable force deviation x3 of adjacent suspenders, the temperature gradient deviation of the tie beam section x4, and the relative elevation deviation y of the control point. p The data; the active control subsystem is mainly used to calibrate control points and raise or lower the bridge deck.

[0035] The present invention discloses an active control method for bridge deck elevation during tie-arch bridge suspender replacement construction and the control system used therein. The control system includes a bridge deck hoisting device and a laser measuring instrument.

[0036] The bridge deck sling-up device consists of a Bailey bridge, temporary suspenders, distribution beams, support beams, jacks, and rubber bearings. The Bailey bridge is the main load-bearing component, spanning the crossbeams of two adjacent suspenders to be replaced. Four temporary suspenders are symmetrically fixed to the middle of the Bailey bridge span with bolts to raise and lower the bridge deck. The distribution beam is located between the upper part of the temporary suspenders and the top surface of the Bailey bridge, and the support beam is located between the lower end of the temporary suspenders and the crossbeam of the suspender to be replaced, used to distribute the load. Four jacks are installed above the distribution beam to tension and unload the four temporary suspenders respectively. Rubber bearings support the two adjacent suspenders to distribute the force at the suspender to be replaced. The laser measuring instrument is placed within a range of 5m to 50m from the bridge, depending on the site conditions, and mainly consists of a laser observation head, a lifting platform, and an alarm.

[0037] The control system used in the active control method for bridge deck elevation during tie-arch bridge hanger replacement construction described in this invention is as follows.

[0038] The data processing subsystem mainly includes a data preprocessing module and a Bayesian module;

[0039] The data preprocessing module includes a data acquisition unit, a theoretical calculation unit, and a dimensionless conversion unit;

[0040] The data acquisition unit is used to collect the measured values ​​of the cable force of the replaced hanger, the temporary hanger, the adjacent hanger, the temperature gradient of the tie beam section, and the elevation of the control point obtained by the laser measuring instrument, cable force gauge, and thermometer.

[0041] The theoretical calculation unit is based on the established theoretical values ​​P of the replaced hanger cable force, temporary hanger cable force, adjacent hanger cable force, tie beam section temperature gradient, and control point elevation. i The optimization equations are used to calculate the theoretical values ​​of the cable force of the replaced hanger, the cable force of the temporary hanger, the cable force of the adjacent hanger, the temperature gradient of the tie beam section, and the elevation of the control point.

[0042] The dimensionless unit transforms the measured values ​​obtained from the data acquisition unit and the theoretical values ​​obtained from the theoretical calculation unit into dimensionless values ​​for the replaced suspender cable force deviation x1, the temporary suspender cable force deviation x2, the adjacent suspender cable force deviation x3, the tie beam section temperature gradient deviation x4, and the control point relative elevation deviation y. p As evidence samples for Bayesian network reasoning, they are input into the Bayesian module;

[0043] The Bayesian module obtains a large number of initial samples through McLeod sampling, and combines the initial samples with evidence samples to form training samples. Bayesian network inference is then performed to obtain the predicted bridge deck elevation value P. * i ;

[0044] The active control subsystem mainly includes an excitation module, a calibration module, and an early warning module;

[0045] The excitation module mainly includes a bridge deck hoisting device, used to raise or lower the bridge deck;

[0046] The calibration module mainly includes a reflective target and a laser measuring instrument, which are used to calibrate the elevation position of control points;

[0047] Based on the elevation prediction information output by the Bayesian module, the excitation module and calibration module work together until the control point elevation reaches P. * i If the laser measuring instrument fails to calibrate with the reflective target, the warning module will issue an alarm, and the excitation module and calibration module will continue to work together until the control point elevation reaches P. * i The module stopped running.

[0048] Beneficial effects:

[0049] 1. The present invention adopts an active control method and system for bridge deck elevation during tie-arch bridge suspender replacement construction. It uses a liftable laser measuring instrument to measure the elevation and a bridge deck hoisting device to achieve synchronous lifting and lowering of the bridge deck. It has high precision and high timeliness, and avoids errors caused by human control methods.

[0050] 2. The present invention employs an active control method and system for bridge deck elevation during tie-arch bridge suspender replacement construction. During the suspender replacement process, the data processing subsystem and the active control subsystem are closely linked, rapidly converting the feedback data information into operational commands for raising or lowering the bridge deck. This enables active control of the bridge deck elevation during suspender replacement, ensuring the structural safety and rational alignment during the construction process in real time and effectively.

[0051] 3. The active control method for bridge deck elevation during tie-arch bridge suspender replacement construction adopted in this invention introduces a Bayesian network model and generates a large number of training samples by combining sampling and measured data, avoiding tedious manual calculations and realizing rapid and intelligent calculation of bridge deck elevation target values.

[0052] 4. The system device provided by the present invention has a simple structure, is easy to install and maintain, has low cost, and does not require a large number of wiring connections. Attached Figure Description

[0053] Figure 1 This is a diagram showing the overall layout of the bridge deck hoisting system.

[0054] Figure 2 This is a schematic diagram of a control point elevation monitoring scenario.

[0055] Figure 3 This is a diagram of the Bayesian network topology.

[0056] Figure 4 This is a schematic diagram of the components of an active control system.

[0057] Figure 1 , Figure 2 In the middle: 1-Replaced boom, 2-Adjacent boom crossbeam, 3-Reflective target, 4-Laser measuring instrument, 5-Adjacent boom, 6-Stretch gauge, 7-Tie beam, 8-Thermometer, 9-Bailey bridge, 10-Temporary boom, 11-Distribution beam, 12-Support beam, 13-Jack, 14-Rubber support, 15-Boom crossbeam, 16-Laser observation head, 17-Lifting platform, 18-Alarm. Detailed Implementation

[0058] To make the objectives and technical solutions of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0059] like Figures 1-4 As shown, a method for actively controlling the bridge deck elevation during the replacement of hangers in a tied-arch bridge is described below:

[0060] Step 1: Install the bridge deck hoisting device at the location of the replaced suspender on the tied arch bridge, spanning the crossbeams of two adjacent suspenders of the replaced suspender; define the connection point between the replaced suspender and the bridge deck as the control point, and use the elevation change of the control point as the feedback indicator of the bridge deck elevation change;

[0061] Reflective targets were placed at the control points and calibrated using a laser measuring instrument to determine the initial elevation P0 of the control points and obtain the control point elevation data for subsequent construction processes.

[0062] Cable force gauges were installed on the replaced suspender, the adjacent suspender, and the bridge deck hoisting device to obtain the measured values ​​of the cable force of the replaced suspender, the cable force of the adjacent suspender, and the cable force of the temporary suspender.

[0063] Thermometers were installed on the surface of the tie beam near the control point to obtain the measured temperature gradient of the tie beam section.

[0064] Step 2: The replacement of the boom requires n working conditions. When the boom replacement reaches working condition i (i = 1, 2, 3, ..., n), the theoretical value of the control point elevation for each working condition is P. i Establish theoretical values ​​P for the cable forces of the replaced hanger, temporary hanger, adjacent hanger, temperature gradient of the tie beam section, and control point elevation. i The optimization equation;

[0065] P i -P i-1 =δ i T i +δ l i T l i +δ x i T x i +δ c i C i = f(T) + g(C)

[0066] Where δi is the influence of the change in vertical displacement of the control point caused by the unit change in the cable force of the replaced boom under each working condition;

[0067] Ti represents the theoretical value of the cable force of the replaced boom under each working condition;

[0068] This refers to the effect of a unit change in the temporary suspender cable force under various working conditions on the vertical displacement of the control point.

[0069] These are the theoretical values ​​of the temporary suspender cable force under various working conditions;

[0070] This represents the influence of a unit change in the cable force of adjacent booms under various working conditions on the vertical displacement of the control point.

[0071] These are the theoretical values ​​of the cable force of adjacent suspenders under each working condition;

[0072] This represents the influence of a unit change in the temperature gradient of the beam section under various working conditions on the vertical displacement of the control points.

[0073] C i The theoretical values ​​of the temperature gradient of the beam section under various working conditions;

[0074] f(T) is about Ti, The function;

[0075] g(C) is about C i The function;

[0076] The theoretical values ​​of the cable force of the replaced hanger, the temporary hanger, the adjacent hanger, and the temperature gradient of the tie beam section are obtained by optimizing the objective function as follows:

[0077]

[0078] Step 3: Based on the measured and theoretical values ​​obtained in Steps 1 and 2, use the following formula:

[0079] (Measured value - Theoretical value) / Theoretical value

[0080] The following parameters were calculated: cable force deviation of the replaced hanger x1, cable force deviation of the temporary hanger x2, cable force deviation of adjacent hangers x3, temperature gradient deviation of the tie beam section x4, and relative elevation deviation of the control point y. p ;

[0081] Step 4: Using the cable force deviation of the replaced suspender x1, the cable force deviation of the temporary suspender x2, the cable force deviation of the adjacent suspender x3, and the temperature gradient deviation of the tie beam section x4 as root node variables, control the relative elevation deviation y of the control point. p Construct a Bayesian network model for the leaf node variables;

[0082] Given the prior: the mean of the root node variables is 0, and the variances are 9%, 12%, 6%, and 40%, respectively; based on the optimization equation in step two, 10 are sampled using MC sampling. 5 1 sample point as the initial sample;

[0083] Step 5: Copy the deviation data obtained in Step 3 10 times. 5 This sample is used as evidence and added to the initial sample in step four to form a training sample, which is used to train the Bayesian network model, thereby obtaining the predicted elevation value P of the control point for each working condition. *i ;

[0084] Step Six: Using the P obtained in Step Five * i As the target value for the elevation of each control point under various operating conditions, the ray point of the laser measuring instrument is controlled in advance at an elevation of P. * i The bridge deck is raised or lowered by adjusting the tension of each jack, and the laser measuring instrument is observed until the reflective target and the laser measuring instrument are successfully calibrated, thus realizing active control of the bridge deck elevation during the replacement of the suspenders.

[0085] The control system used in the active control method for bridge deck elevation during tie-arch bridge suspender replacement construction includes a data processing subsystem and an active control subsystem. The data processing subsystem is mainly used to collect data on the cable force deviation x1 of the suspender being replaced, the cable force deviation x2 of the temporary suspender, the cable force deviation of adjacent suspenders x3, the temperature gradient deviation of the tie beam section x4, and the relative elevation deviation y of the control points. p The data; the active control subsystem is mainly used to calibrate control points and raise or lower the bridge deck.

[0086] The bridge deck lifting device consists of a Bailey bridge 9, temporary suspenders 10, distribution beams 11, support beams 12, jacks 13, and rubber bearings 14. The Bailey bridge 9 is the main load-bearing component, spanning the two adjacent suspender beams 2 of the suspender 1 being replaced. Four temporary suspenders 10 are symmetrically fixed to the middle of the span of the Bailey bridge 9 with bolts to lift and lower the bridge deck. The distribution beam 11 is located between the upper part of the temporary suspenders 10 and the top surface of the Bailey bridge 9, and the support beam 12 is located between the lower end of the temporary suspenders 10 and the crossbeam of the suspender 1 being replaced, used to distribute the load.

[0087] Four jacks 13 are installed above the distribution beam 11 to tension and unload the four temporary lifting rods 10 respectively; rubber supports 14 are placed at two adjacent lifting rods to distribute the force at the lifting rod 1 being replaced;

[0088] The laser measuring instrument is placed within a range of 5m to 50m from the bridge, depending on the site conditions. It mainly consists of a laser observation head 16, a lifting platform 17, and an alarm 18.

[0089] A control system used in an active control method for bridge deck elevation during tie-arch bridge hanger replacement construction is characterized by:

[0090] The data processing subsystem mainly includes a data preprocessing module and a Bayesian module;

[0091] The data preprocessing module includes a data acquisition unit, a theoretical calculation unit, and a dimensionless conversion unit;

[0092] The data acquisition unit is used to collect the measured values ​​of the cable force of the replaced hanger, the temporary hanger, the adjacent hanger, the temperature gradient of the tie beam section, and the elevation of the control point obtained by the laser measuring instrument, cable force gauge, and thermometer.

[0093] The theoretical calculation unit is based on the established theoretical values ​​P of the replaced hanger cable force, temporary hanger cable force, adjacent hanger cable force, tie beam section temperature gradient, and control point elevation. i The optimization equations are used to calculate the theoretical values ​​of the cable force of the replaced hanger, the cable force of the temporary hanger, the cable force of the adjacent hanger, the temperature gradient of the tie beam section, and the elevation of the control point.

[0094] The dimensionless unit transforms the measured values ​​obtained from the data acquisition unit and the theoretical values ​​obtained from the theoretical calculation unit into dimensionless values ​​for the replaced suspender cable force deviation x1, the temporary suspender cable force deviation x2, the adjacent suspender cable force deviation x3, the tie beam section temperature gradient deviation x4, and the control point relative elevation deviation y. p As evidence samples for Bayesian network reasoning, they are input into the Bayesian module;

[0095] The Bayesian module obtains a large number of initial samples through McLeod sampling, and combines the initial samples with evidence samples to form training samples. Bayesian network inference is then performed to obtain the predicted bridge deck elevation value P. * i ;

[0096] The active control subsystem mainly includes an excitation module, a calibration module, and an early warning module;

[0097] The excitation module mainly includes a bridge deck hoisting device, used to raise or lower the bridge deck;

[0098] The calibration module mainly includes a reflective target and a laser measuring instrument, which are used to calibrate the elevation position of control points;

[0099] Based on the elevation prediction information output by the Bayesian module, the excitation module and calibration module work together until the control point elevation reaches P. * i If the laser measuring instrument fails to calibrate with the reflective target, the warning module will issue an alarm, and the excitation module and calibration module will continue to work together until the control point elevation reaches P. * i The module stopped running.

[0100] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for actively controlling the bridge deck elevation during the replacement of hangers in a tied-arch bridge, characterized in that, The control method is as follows: Step 1: Install the bridge deck hoisting device at the location of the replaced suspender on the tied arch bridge, spanning the crossbeams of two adjacent suspenders of the replaced suspender; define the connection point between the replaced suspender and the bridge deck as the control point, and use the elevation change of the control point as the feedback indicator of the bridge deck elevation change; Reflective targets were placed at the control points and calibrated using a laser measuring instrument to determine the initial elevation P0 of the control points and obtain the control point elevation data for subsequent construction processes. Cable force gauges were installed on the replaced suspender, the adjacent suspender, and the bridge deck hoisting device to obtain the measured values ​​of the cable force of the replaced suspender, the cable force of the adjacent suspender, and the cable force of the temporary suspender. Thermometers were installed on the surface of the tie beam near the control point to obtain the measured temperature gradient of the tie beam section. Step 2: The replacement of the boom requires n working conditions. When the boom replacement reaches working condition i (i = 1, 2, 3, ..., n), the theoretical value of the control point elevation for each working condition is P. i Establish theoretical values ​​P for the cable forces of the replaced hanger, temporary hanger, adjacent hanger, temperature gradient of the tie beam section, and control point elevation. i The optimization equation; P i -P i-1 =δ i T i +δ l i T l i +δ x i T x i +δ c i C i =f(T)+g(C) Where δi is the influence of the change in vertical displacement of the control point caused by the unit change in the cable force of the replaced boom under each working condition; Ti represents the theoretical value of the cable force of the replaced boom under each working condition; This refers to the effect of a unit change in the temporary suspender cable force under various working conditions on the vertical displacement of the control point. These are the theoretical values ​​of the temporary suspender cable force under various working conditions; This represents the influence of a unit change in the cable force of adjacent booms under various working conditions on the vertical displacement of the control point. These are the theoretical values ​​of the cable force of adjacent suspenders under each working condition; This represents the influence of a unit change in the temperature gradient of the beam section under various working conditions on the vertical displacement of the control points. C i The theoretical values ​​of the temperature gradient of the beam section under various working conditions; f(T) is about Ti, The function; g(C) is about C i The function; The theoretical values ​​of the cable force of the replaced hanger, the temporary hanger, the adjacent hanger, and the temperature gradient of the tie beam section are obtained by optimizing the objective function as follows: Step 3: Based on the measured and theoretical values ​​obtained in Steps 1 and 2, use the following formula: (Measured value - Theoretical value) / Theoretical value The following parameters were calculated: cable force deviation of the replaced suspender x1, cable force deviation of the temporary suspender x2, cable force deviation of adjacent suspenders x3, temperature gradient deviation of the tie beam section x4, and relative elevation deviation of the control point y. p ; Step 4: Using the cable force deviation of the replaced suspender x1, the cable force deviation of the temporary suspender x2, the cable force deviation of the adjacent suspender x3, and the temperature gradient deviation of the tie beam section x4 as root node variables, control the relative elevation deviation y of the control point. p Construct a Bayesian network model for the leaf node variables; Given the prior: the mean of the root node variables is 0, and the variances are 9%, 12%, 6%, and 40%, respectively; based on the optimization equation in step two, 10 are sampled using MC sampling. 5 1 sample point as the initial sample; Step 5: Copy the deviation data obtained in Step 3 10 times. 5 This sample is used as evidence and added to the initial sample in step four to form a training sample, which is used to train the Bayesian network model, thereby obtaining the predicted elevation value P of the control point for each working condition. * i ; Step Six: Using the P obtained in Step Five * i As the target value for the elevation of each control point under various operating conditions, the ray point of the laser measuring instrument is controlled in advance at an elevation of P. * i The bridge deck is raised or lowered by adjusting the tension of each jack, and the laser measuring instrument is observed until the reflective target and the laser measuring instrument are successfully calibrated, thus realizing active control of the bridge deck elevation during the replacement of the suspenders.

2. The control system used in the active control method for bridge deck elevation during tie-arch bridge hanger replacement construction according to claim 1 is characterized in that: It includes a data processing subsystem and an active control subsystem; the data processing subsystem is mainly used to collect the cable force deviation of the replaced suspender x1, the cable force deviation of the temporary suspender x2, the cable force deviation of the adjacent suspenders x3, the temperature gradient deviation of the tie beam section x4, and the relative elevation deviation of the control point y. p The data; the active control subsystem is mainly used to calibrate control points and raise or lower the bridge deck.

3. The control system used in the active control method for bridge deck elevation during tie-arch bridge hanger replacement construction according to claim 2 is characterized in that, The control system includes a bridge deck hoisting device and a laser measuring instrument; The bridge deck sling-up device consists of a Bailey bridge, temporary suspenders, distribution beams, support beams, jacks, and rubber bearings. The Bailey bridge is the main load-bearing component, spanning the crossbeams of two adjacent suspenders being replaced. Four temporary suspenders are symmetrically fixed to the middle of the Bailey bridge span with bolts to raise and lower the bridge deck. The distribution beam is located between the upper part of the temporary suspenders and the top surface of the Bailey bridge, and the support beam is located between the lower end of the temporary suspenders and the crossbeam of the suspender being replaced, used to distribute the load. Four jacks are installed above the distribution beam to tension and unload the four temporary suspenders respectively. Rubber bearings are placed at two adjacent hangers to distribute the force at the hanger being replaced; the laser measuring instrument is placed within a range of 5m to 50m from the bridge, depending on the site conditions.

4. The control system used in the active control method for bridge deck elevation during tie-arch bridge suspender replacement construction according to claim 2 is characterized in that: The data processing subsystem mainly includes a data preprocessing module and a Bayesian module; The data preprocessing module includes a data acquisition unit, a theoretical calculation unit, and a dimensionless conversion unit; The data acquisition unit is used to collect the measured values ​​of the cable force of the replaced hanger, the temporary hanger, the adjacent hanger, the temperature gradient of the tie beam section, and the elevation of the control point obtained by the laser measuring instrument, cable force gauge, and thermometer. The theoretical calculation unit is based on the established theoretical values ​​P of the replaced hanger cable force, temporary hanger cable force, adjacent hanger cable force, tie beam section temperature gradient, and control point elevation. i The optimization equations are used to calculate the theoretical values ​​of the cable force of the replaced hanger, the cable force of the temporary hanger, the cable force of the adjacent hanger, the temperature gradient of the tie beam section, and the elevation of the control point. The dimensionless unit transforms the measured values ​​obtained from the data acquisition unit and the theoretical values ​​obtained from the theoretical calculation unit into dimensionless values ​​for the replaced suspender cable force deviation x1, the temporary suspender cable force deviation x2, the adjacent suspender cable force deviation x3, the tie beam section temperature gradient deviation x4, and the control point relative elevation deviation y. p As evidence samples for Bayesian network reasoning, they are input into the Bayesian module; The Bayesian module obtains a large number of initial samples through McLeod sampling, and combines the initial samples with evidence samples to form training samples. Bayesian network inference is then performed to obtain the predicted bridge deck elevation value P. * i ; The active control subsystem mainly includes an excitation module, a calibration module, and an early warning module; The excitation module mainly includes a bridge deck hoisting device, used to raise or lower the bridge deck; The calibration module mainly includes a reflective target and a laser measuring instrument, which are used to calibrate the elevation position of control points; Based on the elevation prediction information output by the Bayesian module, the excitation module and calibration module work together until the control point elevation reaches P. * i If the laser measuring instrument fails to calibrate with the reflective target, the warning module will issue an alarm, and the excitation module and calibration module will continue to work together until the control point elevation reaches P. * i The module stopped running.

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