A method and system for optimizing the track alignment of a long-span bridge

Abstract

The present application discloses a method and system for optimizing the alignment of a track for a large-span bridge, comprising: (1) constructing a large-span bridge monitoring system; (2) establishing a refined analysis model for a large-span bridge; (3) determining key control points of bridge deformation and ranking them according to their sensitivity based on the size of the deformation; (4) adjusting and fitting the alignment of the completed bridge track according to the adjustment principle; (5) checking and calculating the radius of the curve of the fitted adjustment alignment, and checking and accepting the alignment according to the requirements of the specification. In the alignment optimization and adjustment process, the present invention fully considers the stress and deformation characteristics of the large-span bridge itself and the alignment characteristics of the bridge actually constructed on site, and takes minimizing the amount of on-site construction adjustment as the principle. By optimizing the design alignment, it is ensured that the construction alignment of the track structure of the large-span bridge meets the relevant requirements of the design acceptance specification.

Description

Technical Field

[0001] The present invention relates to the technical field of linear adjustment of track structures of long-span bridges, and in particular to a method and system for optimizing the linear shape of track structures of long-span bridges. Background Art

[0002] my country has a vast territory, complex terrain, numerous rivers and lakes, and a crisscross network of various water and land transportation networks. When constructing high-speed railways, large-span bridges are often required. The overall stiffness of large-span bridges is relatively small, and the bridge alignment is significantly affected by the second-phase constant load on the bridge, construction deviations, and temperature loads. The existing track structure design alignment is generally a herringbone slope plus a vertical curve or a straight flat slope type. However, in the actual construction process, the track alignment of the completed bridge is usually too different from the design alignment to pass the acceptance inspection directly. Track construction is often difficult to adjust or the adjustment workload is very large. In addition, the track construction adjustment process has a great impact on the total load on the bridge, which leads to a large disturbance in the deformation of the bridge. During the adjustment process, it may also cause the local stress deformation of the bridge to exceed the design range, such as the cable stress exceeding the limit. Therefore, how to ensure that the track alignment of the completed bridge meets the design alignment requirements as much as possible during the construction process is a major technical problem in the construction of large-span track structures.

[0003] Currently, there are related methods for controlling the linear shape of track structures on large-span cable-stayed bridges. For example, patent CN110219246A discloses a method for constructing ballastless track on a large-span flexible bridge. However, the patent focuses on the layout of CPIII and the construction process of the ballastless track, and relatively little consideration is given to the impact of the second-phase constant load on the bridge on the linear shape of the beam surface. Patent CN110846958B discloses a method for controlling the linear shape accuracy of ballastless track construction on a cable-stayed bridge. Patent CN117077251A discloses a method for controlling the linear shape of ballastless track with a large-span steel truss structure. Patent CN116837672A discloses a method for laying ballastless track on a large-span bridge. All of the above patents require a preloading process for the large-span bridge, which makes the construction process relatively complicated and affects the construction period. Patent CN117090140A discloses a construction method for ballastless track of a large-span cable-stayed bridge. Although this patent does not require preloading, it takes into account few factors affecting the bridge alignment and mainly uses finite element models for correction, which is relatively different from the actual situation on site. There are many influencing factors, which makes it difficult to control the final track alignment accuracy. Patent CN114329726A proposes a railway bridge alignment evaluation method based on train driving performance, and evaluates the bridge track alignment through vehicle body acceleration indicators. Patent CN114444177A proposes a railway bridge track laying alignment optimization method based on Fourier series fitting, which uses the measured bridge alignment as the fitting benchmark for the track laying alignment. If the difference from the designed alignment is too great, it will not pass the acceptance inspection, which also poses a huge challenge to the track adjustment capability and has relatively poor applicability. Summary of the Invention

[0004] In response to the technical problems existing in the existing technology, this patent proposes a method and system for optimizing the linear shape of large-span bridge track structures. During the linear shape optimization and adjustment process, the stress and deformation characteristics of the large-span bridge itself and the linear characteristics of the bridge actually constructed on site are fully considered. The principle is to minimize the amount of on-site construction adjustment. By optimizing the design linear shape, it is ensured that the construction linear shape of the large-span bridge track structure meets the relevant requirements of the design acceptance specifications.

[0005] In a first aspect, the present invention provides a method for optimizing the track alignment of a long-span bridge, comprising the following steps:

[0006] Step 1. Build a long-span bridge alignment monitoring system to monitor bridge deformation information;

[0007] Step 2. Establish an initial finite element model to simulate the bridge and track construction process. Based on the long-span bridge alignment monitoring system, the parameters of the initial finite element model are modified to establish a refined analysis model for the long-span bridge.

[0008] Step 3. Analyze the alignment change patterns of the bridge track based on the long-span bridge refined analysis model and the long-span bridge alignment monitoring system, and determine the key points for bridge track alignment control;

[0009] Step 4. Obtain the measured alignment using the long-span bridge alignment monitoring system, compare it with the designed alignment, and perform fitting adjustments on the completed bridge track alignment to obtain a fitting adjustment alignment deformation curve.

[0010] Step 5. Check and accept the fitted adjustment linear deformation curve.

[0011] Furthermore, the long-span bridge alignment monitoring system in step 1 includes a front-end measurement marker, alignment measurement equipment, a high-precision time-space synchronous acquisition and control system, and a visualization module.

[0012] Furthermore, the front-end measurement mark is firmly attached to the crash barrier of the bridge at intervals;

[0013] The linear measurement equipment is used to collect monitoring data of bridge deformation information;

[0014] The high-precision time-space synchronous acquisition and control system controls all linear measurement equipment on the long-span bridge to collect data at the same time. It also calculates the front-end measurement identification coordinates of multiple locations in real time and performs data verification processing to eliminate measurement errors. It compares the pre-input design information with the monitoring data to determine whether the monitoring data is erroneous, eliminates the erroneous data and stores it. It also conducts a longitudinal comparison between the existing monitoring data and historical monitoring data to perform linear prediction, and sets limits to issue early warnings and forecasts for abnormal data.

[0015] The visualization module is based on BIM and GIS technology and is used for visual display and monitoring of monitoring data. It displays the status of the designed bridge and the comparison between the alignment under the ideal design state and the alignment of the bridge at different construction stages.

[0016] Furthermore, the step 3 of establishing a refined analysis model of a long-span bridge includes:

[0017] Collect the design parameters of bridge piers and main beams to establish the initial finite element model;

[0018] Conduct simulation calculations and stress analysis on the bridge and track construction process based on the initial finite element model;

[0019] By comparing the monitoring data of the monitoring system of the large-span dual-purpose steel truss cable-stayed bridge for road and rail with the theoretical data calculated by the initial finite element model, the model parameters of the initial finite element model were corrected and a refined analysis model of the large-span bridge was established.

[0020] Further, the step 3 comprises:

[0021] Based on the refined analysis model of long-span bridges, the stress and deformation laws of bridge tracks under dead load, live load, temperature, and wind load at each construction stage are calculated, and the deformation envelope curves of bridge tracks under different loads are obtained.

[0022] By combining the deformation envelope curves of the bridge track under different loads and the monitoring data of bridge deformation information, the linear variation law of the bridge track is analyzed. Through formula fitting, the functional relationship between the bridge deformation y and the key influencing factors of temperature t and constant load p is established, and the key points of bridge track linear control are determined;

[0023] Sort the key control points from high to low according to their sensitivity to elevation deformation changes.

[0024] Furthermore, the functional relationship is:

[0025] y=f(t,p,x)

[0026] Where x is the horizontal coordinate of the bridge deformation monitoring point.

[0027] Furthermore, the step 4 includes:

[0028] The actual alignment of the track structure on the long-span bridge is measured based on the long-span bridge alignment monitoring system, and the measured alignment is compared with the designed alignment. The elevation deviation between the measured alignment at the key points of the bridge track alignment control and the designed alignment is adjusted to within a first set threshold range by adjusting the cable tension.

[0029] The adjusted measured linear line is fitted using a combination of trigonometric functions and polynomials or a cubic spline curve to obtain a fitted adjusted linear deformation curve. If fitting is not possible, the high-sensitivity control key points are optimized and discarded in the order of sensitivity, and re-fitting is performed;

[0030] At the same time, the measured line shape h(x) and the fitted adjusted line shape deformation curve g(x) are integrated along the longitudinal direction of the long-span bridge respectively, so that the measured line shape and the fitted adjusted line shape deformation curve are equal to the area enclosed by the x-axis within the entire bridge range or the integral of the two is less than the second set threshold.

[0031] Furthermore, the first set threshold is ±10 mm; and the second set threshold is 1% of the integral area of ​​the fitting adjustment linear deformation curve g(x) along the longitudinal direction of the long-span bridge.

[0032] Furthermore, the step 5 includes:

[0033] Check and fit the curvature radius R of each point of the linear deformation curve to make R ≥ 0.4v 2 , where v is the driving speed; after the above conditions are met, the fitted and adjusted bridge track alignment will be used as the acceptance alignment, and the long-wave and short-wave irregularity limit acceptance and dynamic TQI index acceptance will be carried out in accordance with the relevant design acceptance specifications.

[0034] In another aspect, the present invention provides a long-span bridge track alignment optimization system, comprising:

[0035] Monitoring system construction module: It is used to build a long-span bridge alignment monitoring system to monitor bridge deformation information;

[0036] Refined analysis model construction module: This module is used to establish an initial finite element model to simulate the bridge and track construction process, and to modify the parameters of the initial finite element model based on the long-span bridge alignment monitoring system to establish a refined analysis model for the long-span bridge;

[0037] Key control point determination module: This module is used to analyze the linear change law of the bridge track based on the long-span bridge refined analysis model and the long-span bridge linear monitoring system, and determine the key control points of the bridge track linear shape;

[0038] Deformation curve fitting module: It is used to obtain the measured alignment based on the long-span bridge alignment monitoring system, compare it with the designed alignment, and perform fitting adjustment on the bridge track alignment to obtain the fitted adjustment alignment deformation curve;

[0039] Verification and acceptance module: It is used to verify and accept the fitted adjustment linear deformation curve.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention proposes a method for optimizing the linear adjustment of track structures on large-span bridges. After adjustment and optimization, the linear shape better conforms to the deformation characteristics of the bridge structure itself, is more consistent with the bridge stress and actual on-site conditions, is more inclusive and adaptable, and makes on-site linear adjustment more convenient. While ensuring that the linear shape of the track on large-span bridges is more consistent with the actual bridge deformation, it also reduces the workload of linear adjustment, while also ensuring the safety and stability of high-speed train travel.

[0042] The image recognition-based linear monitoring system proposed in this invention improves the accuracy and stability of the monitoring method by designing specific front-end measurement markers. The linear measurement equipment is driven by a low-light CMOS image sensor, solving difficult problems such as remote laser fill light, high-precision edge extraction and noise removal under complex backgrounds, full-cycle stable measurement under large-scale light changes, and high-precision spatiotemporal synchronous acquisition and analysis. It achieves high-resolution, high-frame-rate image acquisition, high-performance image processing, displacement calculation, data transmission, and other functions, with displacement measurement accuracy reaching the millimeter level. The high-precision spatiotemporal synchronous acquisition and control system can control all monitoring equipment on a long-span bridge to collect data at the same time. Through a self-programmed high-precision target center extraction algorithm and a convenient and accurate displacement coefficient calibration method, sub-pixel target center extraction is achieved, ensuring that measurement accuracy meets requirements. At the same time, the coordinates of the front-end measurement markers at multiple locations can be calculated in real time and data verification processing can be performed to eliminate measurement errors, thereby achieving high-precision multi-point joint measurement of track linearity on long-span bridges.

[0043] The present invention establishes a refined analysis model for large-span bridges, uses measured data to continuously correct the calculation parameters of the theoretical model, and establishes a functional relationship y = f(t, p, x) between bridge deformation y and key influencing factors such as temperature t and constant load p through formula fitting. This improves and supplements the bridge deformation under extreme loads that cannot be measured under actual monitoring conditions, covering the most unfavorable conditions that may occur on the entire bridge.

[0044] The present invention uses a combination of polynomials and trigonometric functions or a cubic spline curve to fit the adjusted linear shape, re-smoothing and conforming to the entire bridge linear shape. This formula is capable of fitting any linear shape, and the correlation coefficient can reach above 0.98. By integrating the actual bridge track measurement linear shape and the fitted adjusted linear shape deformation curve along the longitudinal direction of the long-span bridge, the integral calculation results are made as equal as possible or the difference between the two integrals is very small. When fitting is impossible, the highly sensitive points are preferentially discarded for re-fitting, which greatly reduces the workload of linear adjustment, reduces the significant impact of the change in the second-phase constant load of the bridge after the linear adjustment on the overall stress and deformation of the bridge, optimizes the local stress of the long-span bridge, makes the fitted adjusted linear shape more consistent with the deformation characteristics of the bridge, and makes the second-phase constant load of the entire long-span bridge more balanced.

[0045] The present invention adjusts the curvature radius R of each point of the linear deformation curve by checking and fitting, so that R≥0.4v2 (v is the driving speed), which ensures the comfort of driving on the long-span bridge. At the same time, the long-wave and short-wave unevenness limit acceptance and dynamic TQI index acceptance of the fitted adjusted line are carried out in accordance with the requirements of the specifications, which comprehensively guarantees the operational safety of high-speed trains on the long-span bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 This is a schematic diagram of the overall process of a method for adjusting and optimizing the linear shape of a track structure of a long-span bridge according to the present invention;

[0048] Figure 2 This is a diagram showing the composition of a monitoring system for a method for optimizing the linear adjustment of a track structure of a long-span bridge according to the present invention;

[0049] Figure 3 This is a schematic diagram of full-bridge alignment measurement of a long-span bridge alignment monitoring system according to a method for adjusting and optimizing the alignment of a track structure of a long-span bridge according to the present invention;

[0050] Figure 4 It is a schematic diagram of a long-span bridge alignment monitoring scheme of a long-span bridge track structure alignment optimization method according to the present invention;

[0051] Figure 5 It is a linear adjustment fitting schematic diagram of a linear adjustment optimization method for a long-span bridge track structure according to the present invention;

[0052] Figure 6 It is a schematic diagram of the integration principle of a method for optimizing the linear adjustment of a track structure of a large-span bridge according to the present invention.

[0053] In the figure: 1. Crash barrier, 2. Front-end measurement mark, 3. Linear measurement equipment, 4. Beam surface. DETAILED DESCRIPTION

[0054] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0055] Example 1

[0056] like Figure 1 As shown, the key steps of the method for optimizing the linear adjustment of the track structure of a large-span bridge of the present invention include: (1) constructing a large-span bridge monitoring system; (2) establishing a refined analysis model of the large-span bridge; (3) determining the key control points of the bridge deformation and ranking them according to the sensitivity of the deformation size; (4) adjusting and fitting the linear shape of the completed bridge track according to the adjustment principle; (5) checking and calculating the radius of the deformation curve of the fitted adjustment linear shape, and checking and accepting the linear shape according to the requirements of the specification.

[0057] S1: Building a long-span bridge monitoring system

[0058] The long-span bridge alignment monitoring system includes front-end measurement identification, alignment measurement equipment, high-precision time-space synchronous acquisition and control system, and visualization module. Figure 2 shown.

[0059] The front end measurement mark 1 is firmly attached to the crash barrier 2 of the bridge at intervals. Figure 3 As shown, the distance between the front-end measurement marks is 3m.

[0060] The linear measurement device 3 is used to collect bridge deformation information. It's driven by a low-light CMOS image sensor and employs remote laser fill-light technology to improve the accuracy of identifying coordinates of measurement markers at the bridge's front end. The linear measurement device incorporates a self-programmed deformation recognition algorithm, enabling high-precision AI-based edge extraction and noise removal in complex backgrounds, with errors controlled to sub-millimeter levels. This enables real-time processing and analysis of track height data within the field device.

[0061] The single linear measurement device can identify the position changes of several front-end measurement marks within a certain range; multiple linear measurement devices are arranged longitudinally along the long-span bridge deck 4, and each set of linear measurement devices has a certain length of overlapping measurement area. Error correction is performed on the measurement point positions of the overlapping measurement sections; in this example, the monitoring range of each linear measurement device is 60m, and each linear measurement device has a 10m overlapping measurement area, such as Figure 4 shown.

[0062] The linear measurement equipment monitors the entire length of the bridge, connecting bridge positions at the same moment in time to form a curve of bridge linearity. The linearity at different times and under different circumstances is relative to the CPIII measuring point at the tower. By obtaining the absolute coordinates of the CPIII measuring point at the tower, the absolute linearity of the bridge at the time of measurement is determined.

[0063] The high-precision spatiotemporal synchronous acquisition and control system can control all monitoring equipment on a long-span bridge to collect data at the same time. Through a self-programmed high-precision target center extraction algorithm and a convenient and accurate displacement coefficient calibration method, sub-pixel target center extraction can be achieved. Simultaneously, the front-end measurement identification coordinates of multiple locations can be calculated in real time and data verification can be performed to eliminate measurement errors, enabling high-precision multi-point joint measurement of track alignment on long-span bridges. Furthermore, by comparing pre-input design data with monitoring data, it can automatically determine whether the measured data is erroneous, eliminate erroneous data, and store it, thus achieving monitoring data storage.

[0064] The high-precision spatiotemporal synchronous acquisition and control system is based on a deep learning algorithm, which vertically compares the currently collected data with historical data, can perform linear predictions, and issue early warnings and forecasts for abnormal data by setting limits.

[0065] The visualization module is based on BIM and GIS technology and is used for visual display and monitoring of measurement information. It can display the bridge status information of the designed bridge and the comparison information between the alignment under the ideal design state and the alignment of the bridge at different construction stages.

[0066] The long-span bridge monitoring system can also be used for the safe operation and maintenance of track structures on subsequent long-span bridges.

[0067] S2: Establish a detailed analysis model for long-span bridges

[0068] Before establishing the detailed analysis model of the large-span bridge, it is necessary to collect key parameters such as the design elastic modulus and cross-sectional size parameters of the piers and main beams, and design load data; perform simulation calculations and force analysis on the bridge and track construction process, and theoretically calculate the force and deformation laws of the bridge and track under the effects of dead loads, live loads, temperature, wind loads, etc. at each construction stage to obtain the deformation envelope curve of the bridge and track under different loads.

[0069] S3: Determine the critical control points of bridge deformation

[0070] The key control points need to be calculated by combining the deformation envelope curve of the bridge track under different loads calculated by bridge track theory and the bridge line monitoring data, and by fitting the formula to establish the functional relationship y=f(t,p,x) between the bridge deformation y and key influencing factors such as temperature t and dead load p, such as the pier position, bridge tower position, maximum deflection position, mid-span position, 1 / 4 span position, etc. Figure 5 shown.

[0071] The key control points are sorted from high to low according to their sensitivity to elevation deformation changes.

[0072] S4: Fit and adjust the track alignment of the completed bridge according to the adjustment principles

[0073] The adjustment principles include:

[0074] ① Compare the measured alignment with the designed alignment. First, adjust the elevation deviation of the measured alignment at the key control points to within ±10mm. Use a combination of trigonometric functions and polynomials or a cubic spline curve to fit the adjusted alignment and re-smoothly connect the full bridge alignment. The correlation coefficient of the alignment fitting should be no less than 0.98.

[0075] ② Integrate the measured line shape h(x) and the fitted adjustment line shape deformation curve g(x) along the longitudinal direction of the long-span bridge so that the area enclosed by the measured line shape of the bridge track and the fitted adjustment line shape deformation curve within the entire bridge range and the x-axis is as equal as possible or the difference between the integrals of the two is very small, that is, like Figure 6 shown.

[0076] ③ In the above-mentioned linear calculation and fitting process, under the premise of ensuring that the elevation deviation of the control key points of the measured linear shape of the bridge track and the control key points corresponding to the designed linear shape is within the range of ±10mm, if the integrals of the actual measured linear shape h(x) and the fitted adjustment linear deformation curve g(x) along the longitudinal direction of the bridge are difficult to be equal or the integral difference between the two is very different, the actual corresponding second-phase constant load of the bridge corresponding to the actual measured linear shape is very different from the second-phase constant load of the fitted adjustment linear shape, and when fitting is impossible, the high-sensitivity control key points are optimized and discarded according to the sensitivity order, and the fitting is re-performed.

[0077] This example uses a highly sensitive control point at midspan as an example. The original design alignment had a maximum deflection of 80mm at midspan, while the actual bridge alignment had a maximum deflection of 100mm at midspan. Since fitting adjustments were not possible according to principles 1 and 2 above, the midspan control point was discarded, based on the 100mm midspan deflection. While ensuring that the remaining control points met principles 1 and 2 above, a smoothed alignment was refitted to obtain the final acceptance alignment.

[0078] S5: Check and accept the fitted adjustment linear deformation curve

[0079] The fitting adjustment linear deformation curve verification calculation needs to calculate the curvature radius R of each point of the fitting adjustment linear deformation curve so that R ≥ 0.4v 2 (v is the driving speed);

[0080] The fitting adjustment line shape acceptance includes the acceptance of the unevenness limits of the long wave 60m chord length and the short wave 10m chord length and the dynamic TQI index acceptance.

[0081] Example 2

[0082] A specific embodiment of the present invention further provides a long-span bridge track alignment optimization system, comprising:

[0083] Monitoring system construction module: It is used to build a long-span bridge alignment monitoring system to monitor bridge deformation information;

[0084] Refined analysis model construction module: This module is used to establish an initial finite element model to simulate the bridge and track construction process, and to modify the parameters of the initial finite element model based on the long-span bridge alignment monitoring system to establish a refined analysis model for the long-span bridge;

[0085] Key control point determination module: This module is used to analyze the linear change law of the bridge track based on the long-span bridge refined analysis model and the long-span bridge linear monitoring system, and determine the key control points of the bridge track linear shape;

[0086] Deformation curve fitting module: It is used to obtain the measured alignment based on the long-span bridge alignment monitoring system, compare it with the designed alignment, and perform fitting adjustment on the bridge track alignment to obtain the fitted adjustment alignment deformation curve;

[0087] Verification and acceptance module: It is used to verify and accept the fitted adjustment linear deformation curve.

[0088] The above is only a preferred specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.

[0089] It should be understood that parts not elaborated in detail in this specification belong to the prior art.

[0090] It should be understood that the above description of the preferred embodiment is relatively detailed and cannot be regarded as limiting the scope of protection of the patent of the present invention. Under the guidance of the present invention, ordinary technicians in this field can also make substitutions or modifications without departing from the scope of protection of the claims of the present invention, which all fall within the scope of protection of the present invention. The scope of protection requested by the present invention shall be based on the attached claims.

Claims

1. A method for optimizing the track alignment of a long-span bridge, characterized in that: The following steps are involved: Step 1. Build a long-span bridge alignment monitoring system to monitor bridge deformation information; Step 2. Establish an initial finite element model to simulate the bridge and track construction process. Based on the long-span bridge alignment monitoring system, the parameters of the initial finite element model are modified to establish a refined analysis model for the long-span bridge. Step 3. Analyze the alignment variation patterns of the bridge track based on the long-span bridge refined analysis model and the long-span bridge alignment monitoring system, and determine the key points for bridge track alignment control. This includes: calculating the stress and deformation patterns of the bridge track under dead load, live load, temperature, and wind load at each construction stage based on the long-span bridge refined analysis model, and obtaining deformation envelope curves of the bridge track under different loads. By combining the deformation envelope curves of the bridge track under different loads and the monitoring data of bridge deformation information, the linear variation law of the bridge track is analyzed. Through formula fitting, the functional relationship between the bridge deformation y and the key influencing factors of temperature t and constant load p is established, and the key points of bridge track linear control are determined; Sort the key control points from high to low according to the sensitivity of elevation deformation change; Step 4. Obtain the measured alignment based on the long-span bridge alignment monitoring system, compare it with the designed alignment, and perform fitting adjustments on the completed bridge track alignment to obtain a fitting adjustment alignment deformation curve; including: The actual alignment of the track structure on the long-span bridge is measured based on the long-span bridge alignment monitoring system, and the measured alignment is compared with the designed alignment. The elevation deviation between the measured alignment at the key points of the bridge track alignment control and the designed alignment is adjusted to within a first set threshold range by adjusting the cable tension. The adjusted measured linear line is fitted using a combination of trigonometric functions and polynomials or a cubic spline curve to obtain a fitted adjusted linear deformation curve. If fitting is not possible, the high-sensitivity control key points are optimized and discarded in the order of sensitivity, and re-fitting is performed; At the same time, the measured line shape and fitting adjustment of linear deformation curve Integrate along the longitudinal direction of the long-span bridge so that the measured linear shape and the fitted adjusted linear shape deformation curve are equal to the area enclosed by the x-axis within the entire bridge range, or the integral of the two is less than a second set threshold; Step 5. Check and accept the fitted adjustment linear deformation curve.

2. The long-span bridge track alignment optimization method according to claim 1, characterized in that: The long-span bridge alignment monitoring system in step 1 includes a front-end measurement marker, alignment measurement equipment, a high-precision time-space synchronous acquisition and control system, and a visualization module.

3. The long-span bridge track alignment optimization method according to claim 2, characterized in that: The front-end measurement marks are firmly attached to the crash barrier of the bridge at intervals; The linear measurement equipment is used to collect monitoring data of bridge deformation information; The high-precision time-space synchronous acquisition and control system controls all linear measurement equipment on the long-span bridge to collect data at the same time. It also calculates the front-end measurement identification coordinates of multiple locations in real time and performs data verification processing to eliminate measurement errors. It compares the pre-input design information with the monitoring data to determine whether the monitoring data is erroneous, eliminates the erroneous data and stores it. It also conducts a longitudinal comparison between the existing monitoring data and historical monitoring data to perform linear prediction, and sets limits to issue early warnings and forecasts for abnormal data. The visualization module is based on BIM and GIS technology and is used for visual display and monitoring of monitoring data. It displays the status of the designed bridge and the comparison between the alignment under the ideal design state and the alignment of the bridge at different construction stages.

4. The method for optimizing the track alignment of a long-span bridge according to claim 1, wherein: The step 3 of establishing a long-span bridge refined analysis model includes: Collect the design parameters of bridge piers and main beams to establish the initial finite element model; Conduct simulation calculations and stress analysis on the bridge and track construction process based on the initial finite element model; By comparing the monitoring data of the monitoring system of the large-span dual-purpose steel truss cable-stayed bridge for road and rail with the theoretical data calculated by the initial finite element model, the model parameters of the initial finite element model were corrected and a refined analysis model of the large-span bridge was established.

5. The method for optimizing the track alignment of a long-span bridge according to claim 1, characterized in that: The functional relationship is: y=f(t,p,x) Where x is the horizontal coordinate of the bridge deformation monitoring point.

6. The method for optimizing the track alignment of a long-span bridge according to claim 1, characterized in that: The first set threshold is ±10 mm; the second set threshold is 1% of the integral area of ​​the fitting adjustment linear deformation curve g(x) along the longitudinal direction of the long-span bridge.

7. The method for optimizing the track alignment of a long-span bridge according to claim 1, characterized in that: The step 5 comprises: Check and fit the curvature radius R of each point of the linear deformation curve to make R ≥ 0.4v 2 , where v is the driving speed; after the above conditions are met, the fitted and adjusted bridge track alignment will be used as the acceptance alignment, and the long-wave and short-wave irregularity limit acceptance and dynamic TQI index acceptance will be carried out in accordance with the relevant design acceptance specifications.

8. A long-span bridge track alignment optimization system, characterized in that: include: Monitoring system construction module: It is used to build a long-span bridge alignment monitoring system to monitor bridge deformation information; Refined analysis model construction module: This module is used to establish an initial finite element model to simulate the bridge and track construction process, and to modify the parameters of the initial finite element model based on the long-span bridge alignment monitoring system to establish a refined analysis model for the long-span bridge; Key control point determination module: This module is used to analyze the linear change law of the bridge track based on the long-span bridge refined analysis model and the long-span bridge linear monitoring system, and determine the key control points of the bridge track linear shape; Deformation curve fitting module: It is used to obtain the measured alignment based on the long-span bridge alignment monitoring system, compare it with the designed alignment, and perform fitting adjustment on the bridge track alignment to obtain the fitted adjustment alignment deformation curve; Calculation and acceptance module: It is used to check and accept the fitting adjustment linear deformation curve; The long-span bridge track alignment optimization system is used to execute the steps in the long-span bridge track alignment optimization method described in any one of claims 1-7.

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