A method and system for evaluating the overturning resistance of a flange plate

Abstract

This invention discloses a method and system for evaluating the overturning resistance of flange plates, including a comprehensive evaluation method for the structural condition of concrete T-beam flange plates, and the dimensions and parameters of the flange plate overturning resistance test model, as well as the test method and evaluation method. This test and evaluation method can assess the damage state and overturning resistance of existing concrete T-beam flange plate structures, ensuring the safety of T-beam flange plate structures during operation.

Description

Technical Field

[0001] This invention relates to the field of full-scale model test reinforcement of concrete beams, and in particular to a method and system for evaluating the overturning resistance of flange plates. Background Technology

[0002] Concrete T-beams are a widely used simply supported beam structure in railways, highways, and municipal roads both domestically and internationally. This structural form leverages the excellent material properties of concrete and the load-bearing capacity of beam structures, making it a technically and economically sound structural option. In my country, railway bridges are primarily prestressed concrete beam bridges. These structures have clearly defined load-bearing capacities, are simple to construct, and provide sufficient stiffness and stability for train operation. Prestressed concrete T-beams offer advantages such as high load-bearing capacity, low material consumption, light weight, good stability, and convenient construction and erection. They are a typical beam structure in bridge construction and are widely used in railway bridges.

[0003] The concrete T-beam structure of railway bridges features vertical ballast retaining walls at the transverse ends of the T-beams, which fix the ballast within a certain range below the rails, ensuring smooth and long-term train operation. During railway operation, periodic vibrations and noise are generated due to the interaction between trains, bridges, and tracks. Therefore, noise reduction devices are necessary when railway bridges pass through densely populated areas such as villages and cities. Sound barrier devices are installed on the outer side of the concrete T-beam flanges, transferring the structural weight, pedestrian loads, and wind pressure to the retaining walls and flanges via supports and embedded T-steels. The simply supported T-beam sound barrier bears live loads such as wind loads and train aerodynamic forces during railway operation; in coastal areas, typhoon loads must be considered. The flanges of the simply supported T-beam sound barrier bearing this load are thin-plate structures, and their structural stress distribution differs significantly from theoretical calculations. The base of the retaining wall is a right-angled stress concentration zone, and the flange at this location is a thin-plate structure. This causes premature cracking of the structure after it is subjected to load, preventing the reinforcing steel from fully utilizing its tensile strength, thus reducing the structure's durability and ultimate bearing capacity. Therefore, it is necessary to assess the overturning resistance of the concrete T-beam flange plate structure to ensure the safe use of concrete bridge structures.

[0004] On the other hand, as the construction of concrete beam structures becomes more widespread and the operating time continues to increase, some bridges are showing signs of deterioration and damage. Therefore, it is necessary to evaluate and analyze the overturning resistance of the flange plates of concrete T-beams to ensure the operational safety of the beam structures.

[0005] In railway operations, incidents have occurred where retaining walls have collapsed entirely due to cracking at the junction of the flange structure and the retaining wall, as well as under various loads, causing line interruptions and other accidents. Bridge structures are frequently used to cross railway and highway lines, and the collapse of retaining walls poses a significant risk of personal injury and property damage. However, currently, there are no methods for condition assessment of concrete T-beam flange structures, and there is a lack of overturning resistance testing and analysis methods for concrete T-beam flange structures. There is an urgent need for experimental assessment and computational analysis of concrete T-beam flange structures to ensure their operational safety and prevent major safety accidents associated with bridge flange structures.

[0006] To address the aforementioned issues, a method for evaluating the overturning resistance of flange plates is needed. Summary of the Invention

[0007] This invention addresses the current lack of methods for condition assessment of concrete T-beam flange structures, as well as the absence of overturning resistance testing and analysis methods for concrete T-beam flange structures. There is an urgent need for experimental assessment and computational analysis of concrete T-beam flange structures to ensure their operational safety and prevent major safety accidents. This invention provides a method for assessing the overturning resistance of flanges, thus solving the aforementioned problems.

[0008] This invention provides a method for evaluating the overturning resistance of a flange, comprising the following steps:

[0009] S1. Evaluate the structural status of the flange plate to be tested to determine whether the current flange plate needs to undergo an anti-overturning test. If yes, proceed to step S2; otherwise, output the structural status of the flange plate.

[0010] S2. Construct a flange anti-overturning performance evaluation system based on the original flange structure;

[0011] S3. Conduct a loading test on the flange plate overturning performance evaluation system and record the test bearing capacity as an evaluation parameter;

[0012] S4. Select the section with the largest load as the first check section, select the section with the smallest cross-sectional size as the second check section, and select the section with significant changes in cross-section and stress concentration as the third check section.

[0013] S5. Calculate the bearing capacity M according to the longitudinal unit section of each check section;

[0014] S6, calculate the bearing capacity M c With test bearing capacity M t Comparing the values, the smaller value is taken as the structural bearing capacity M;

[0015] S7. Calculate the internal force values ​​at each key section of the flange plate according to the various self-weights and wind loads specified in the beam structure design code, and use these as the design load internal force M. d ;

[0016] S8. Divide the structural bearing capacity obtained from the analysis by the internal force of the design load to obtain the safety factor of the check section, as shown in the following formula:

[0017]

[0018] Where n is the safety factor; M i Let M be the bearing capacity of section i; di Design the internal forces of the load on section i;

[0019] S9. Based on the overturning resistance evaluation level corresponding to the obtained safety factor, the overturning resistance status of the flange structure is obtained.

[0020] The smaller value between the calculated bearing capacity and the test bearing capacity is taken as the bearing capacity of the first check section, and the ratio of the bearing capacity to the design load is the safety factor of the first check section.

[0021] In the second check section, the smaller value between the calculated bearing capacity and the test bearing capacity is taken as the bearing capacity of this section, and the ratio of the bearing capacity to the design load is the safety factor of the second check section.

[0022] In the third check section, the smaller value between the calculated bearing capacity and the test bearing capacity is taken as the bearing capacity of this section, and the ratio of the bearing capacity to the design load is the safety factor of the third check section; (4) Compare the safety factors of the first, second and third check sections, and take the minimum value as the structural safety factor.

[0023] The method for evaluating the overturning resistance of a flange plate according to the present invention, as a preferred embodiment, includes the following specific steps in the structural state evaluation of step S1: visual inspection, crack detection, and reinforcement protective layer thickness testing of the flange plate to be tested.

[0024] The specific evaluation method for visual inspection is as follows:

[0025]

[0026] Where R1 is the damage coefficient of visual inspection, T1 is the tilt angle of the retaining wall, T2 is the damaged area of ​​the key inspection area, M1 is the tilt limit value of the retaining wall, and M2 is the total area of ​​the key inspection area.

[0027] The specific evaluation method for crack detection is as follows:

[0028]

[0029] Where R2 is the damage coefficient for crack detection, H1 is the longitudinal length of the crack in the key inspection area, H2 is the crack width in the key inspection area, K1 is the total longitudinal length of the flange plate inspection area, and K2 is the limit value of the crack width of the T-beam flange plate structure.

[0030] The specific evaluation method for testing the thickness of the concrete cover for reinforcing bars is as follows:

[0031]

[0032] Wherein, R3 is the damage coefficient of the concrete cover thickness test, F1 is the test value of the concrete cover thickness of the upper transverse reinforcement of the flange slab in the key inspection area, F2 is the design value of the concrete cover thickness of the upper transverse reinforcement of the flange slab in the key inspection area, and P is the over-thickness limit value of the concrete cover thickness of the upper transverse reinforcement of the flange slab in the key inspection area.

[0033] The formula for calculating the state result R of the concrete T-beam flange plate structure is as follows:

[0034]

[0035] Where Pi is the dynamic weighting weight of the detection system, which shows the impact of key indicators on the structural state through dynamic weighting; Ri is the damage coefficient of each detection system.

[0036] Based on the state result R of the concrete T-beam flange plate structure, a conclusion can be drawn as to whether the current flange plate needs to undergo an anti-overturning test.

[0037] The method for evaluating the overturning resistance of a flange plate according to the present invention, in a preferred embodiment, specifically includes step S5 as follows:

[0038] S51. Based on the plane section assumption of strain, calculate the corresponding stress using the following formula:

[0039] σ c =ε c E c

[0040] σ s =ε s E s

[0041] Where, σ c For concrete stress; ε c E represents the concrete strain. c For concrete elastic modulus; σ s For the stress in the reinforcing steel; ε s E represents the strain of the reinforcing steel. s For the elastic modulus of the steel reinforcement;

[0042] S52. The cross-section is calculated based on the stress at various points, determining the stress on the reinforcing steel and concrete within the cross-section.

[0043] F c =σ c A c

[0044] F s =σ s A s

[0045] Among them, F c For concrete bearing the load; A c For concrete area; F s For the reinforcement to bear the stress; F s The area of ​​the reinforcing steel bars;

[0046] S53. Obtain the forces and lever arms H of the concrete and steel reinforcement based on the equilibrium equations, where the equilibrium equations are:

[0047] F c +F s =0;

[0048] S54. Assuming the cross-section reaches its limit condition, calculate the bearing capacity of the cross-section using the following formula:

[0049] M c =F s H

[0050] Among them, M c The bearing capacity of the cross section is calculated, where H is the lever arm.

[0051] The method for evaluating the overturning resistance of a flange plate according to the present invention, in a preferred embodiment, specifically includes step S3 as follows:

[0052] The flange plate overturning performance evaluation system was fixed on the test bench using a fixing device, and a loading test was performed on the flange plate overturning performance evaluation system.

[0053] The loading test consists of 5 loading cycles. The first loading cycle is the initial loading cycle, which is used to determine the cracking load of the model specimen.

[0054] The maximum values ​​in the second, third, and fourth loading cycles are the maximum values ​​in the design load combination cases, which are used to evaluate the structural stability.

[0055] The fifth loading cycle loads the specimen to the final failure state, and the maximum load value is the test bearing capacity of the structure.

[0056] This invention provides a flange plate anti-overturning performance evaluation system, comprising a retaining wall, two flange plate structures, a support, ancillary structures, and anchor bolts. The two flange plate structures are arranged on both sides of the auxiliary structures. The anchor bolts are vertically arranged through the auxiliary structures for fixing them. The retaining wall is vertically arranged on the outer side of the flange plate structures. The support is arranged on the outer side of the retaining wall. The reinforcement configuration, dimensions, and materials of the flange plate structures and the support are consistent with those of the flange plate to be tested. The longitudinal length of the retaining wall, the longitudinal length of the flange plate structures, the longitudinal length of the support, and the longitudinal length of the auxiliary structures are all the sum of the length of the embedded parts being 1 times the longitudinal length and 2 times the vertical height.

[0057] The method for evaluating the overturning resistance of a flange plate according to the present invention, as a preferred method, also includes testing the displacement value, steel bar strain, concrete strain, and crack span during the loading test.

[0058] The method for evaluating the overturning resistance of a flange plate according to the present invention, as a preferred embodiment, is as follows: the first cross-section is the inner surface plane of the retaining wall, the second cross-section is the vertical plane at the flange plate connection, and the third cross-section is the horizontal cross-section at the root of the retaining wall.

[0059] The beneficial effects of this invention are as follows:

[0060] (1) This method can be used to determine the overturning resistance of concrete T-beam flange plates, ensure the safety of the structure during operation, and promptly reinforce those with poor overturning resistance to avoid safety accidents.

[0061] (2) Load levels can be classified by considering three factors: design load, cracking load and ultimate load under different load combinations.

[0062] (3) Fully consider the possible causes of overturning and select the most suitable check section to make this method more reliable. Attached Figure Description

[0063] Figure 1 This is a schematic diagram of a method for evaluating the overturning resistance of a flange. Detailed Implementation

[0064] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0065] Example 1

[0066] like Figure 1 As shown, a method for evaluating the overturning resistance of a flange includes the following steps:

[0067] S1. Evaluate the structural status of the flange plate to be tested to determine whether the current flange plate needs to undergo an anti-overturning test. If yes, proceed to step S2; otherwise, output the structural status of the flange plate.

[0068] S2. Construct a flange anti-overturning performance evaluation system based on the original flange structure;

[0069] S3. Conduct a loading test on the flange plate overturning performance evaluation system and record the test bearing capacity as an evaluation parameter;

[0070] S4. Select the section with the largest load as the first check section, select the section with the smallest cross-sectional size as the second check section, and select the section with significant changes in cross-section and stress concentration as the third check section.

[0071] S5. Calculate the bearing capacity M according to the longitudinal unit section of each check section;

[0072] S6, calculate the bearing capacity M c With test bearing capacity M t Comparing the values, the smaller value is taken as the structural bearing capacity M;

[0073] S7. Calculate the internal force values ​​at each key section of the flange plate according to the various self-weights and wind loads specified in the beam structure design code, and use these as the design load internal force M. d ;

[0074] S8. Divide the structural bearing capacity obtained from the analysis by the internal force of the design load to obtain the safety factor of the check section, as shown in the following formula:

[0075]

[0076] Where n is the safety factor; M i Let M be the bearing capacity of section i; di Design the internal forces of the load on section i;

[0077] S9. Based on the overturning resistance evaluation level corresponding to the obtained safety factor, the overturning resistance status of the flange structure is obtained.

[0078] The following is an evaluation table of the overturning resistance of the flange plate of the concrete T-beam:

[0079]

[0080] The longitudinal length of the model specimen was used to calculate the effects of the ballast wall's self-weight, sidewalk slab weight, sidewalk support weight, sound barrier weight, sidewalk live load, aerodynamic forces, cable trough weight, and wind load. Based on the application environment of the T-beam, an appropriate design load calculation method was selected to calculate the transverse overturning load of the T-beam flange. The design loads were then transferred to the check sections to obtain the final design loads.

[0081] Visual inspection involves observing the appearance of the concrete T-beam flange structure with the naked eye, checking whether the retaining wall is obviously tilted or has obvious damage. Crack detection involves observing and detecting the crack condition and width of the concrete T-beam flange, with a focus on the crack condition at the junction of the retaining wall and the flange. The concrete cover thickness test measures the concrete cover thickness of the reinforcing steel in the concrete T-beam flange, with a focus on the cover thickness of the upper transverse reinforcing steel in the flange.

[0082] Specialized testing instruments are required for tilt testing, crack width testing, and reinforcement cover thickness testing.

[0083] After visual inspection, crack detection, and assessment of the thickness of the reinforcing steel cover, a comprehensive evaluation of the condition of the concrete T-beam flange structure is conducted to determine whether an overturning test is required.

[0084] The structural condition assessment in step S1 specifically includes: visual inspection, crack detection, and reinforcement cover thickness testing of the flange plate to be tested;

[0085] The specific evaluation method for visual inspection is as follows:

[0086]

[0087] Where R1 is the damage coefficient of visual inspection, T1 is the tilt angle of the retaining wall, T2 is the damaged area of ​​the key inspection area, M1 is the tilt limit value of the retaining wall, and M2 is the total area of ​​the key inspection area.

[0088] The specific evaluation method for crack detection is as follows:

[0089]

[0090] Where R2 is the damage coefficient for crack detection, H1 is the longitudinal length of the crack in the key inspection area, H2 is the crack width in the key inspection area, K1 is the total longitudinal length of the flange plate inspection area, and K2 is the limit value of the crack width of the T-beam flange plate structure.

[0091] The specific evaluation method for testing the thickness of the concrete cover for reinforcing bars is as follows:

[0092]

[0093] Wherein, R3 is the damage coefficient of the concrete cover thickness test, F1 is the test value of the concrete cover thickness of the upper transverse reinforcement of the flange slab in the key inspection area, F2 is the design value of the concrete cover thickness of the upper transverse reinforcement of the flange slab in the key inspection area, and P is the over-thickness limit value of the concrete cover thickness of the upper transverse reinforcement of the flange slab in the key inspection area.

[0094] The formula for calculating the state result R of the concrete T-beam flange plate structure is as follows:

[0095]

[0096] Where Pi is the dynamic weighting weight of the detection system, which shows the impact of key indicators on the structural state through dynamic weighting; Ri is the damage coefficient of each detection system.

[0097] Based on the state result R of the concrete T-beam flange plate structure, a conclusion can be drawn as to whether the current flange plate needs to undergo an anti-overturning test.

[0098] The impact of each sub-detection system on the degree of damage to the T-beam flange plate structure is weighted as follows:

[0099] Weighting coefficients Weight Crack state P2 40％ Appearance condition inspection coefficient P1 30％ Reinforcing bar protective layer thickness P3 30％

[0100] Based on the range of the theoretical maximum and minimum values ​​of the final result R and the degree of damage, the final state results are divided into five damage levels: slight, moderate, moderate, severe, and extremely severe.

[0101] The structural condition of concrete T-beam flanges is classified into four levels: A, B, C, and D. Level A is further divided into two grades: AA and A1. Grade D represents minor deterioration, Grade C represents moderate deterioration, Grade B represents severe deterioration, A1 represents severe deterioration, and AA represents extremely severe deterioration. The evaluation and measures involved for each deterioration level are shown in the table below:

[0102]

[0103] Step S5 specifically includes:

[0104] S51. Based on the plane section assumption of strain, calculate the corresponding stress using the following formula:

[0105] σ c =ε c E c

[0106] σ s =ε s E s

[0107] Where, σ c For concrete stress; ε c E represents the concrete strain. c For concrete elastic modulus; σ s For the stress in the reinforcing steel; ε s E represents the strain of the reinforcing steel. s For the elastic modulus of the steel reinforcement;

[0108] S52. The cross-section is calculated based on the stress at various points, determining the stress on the reinforcing steel and concrete within the cross-section.

[0109] F c =σc A c

[0110] F s =σ s A s

[0111] Among them, F c For concrete bearing the load; A c For concrete area; F s For the reinforcement to bear the stress; F s The area of ​​the reinforcing steel bars;

[0112] S53. Obtain the forces and lever arms H of the concrete and steel reinforcement based on the equilibrium equations, where the equilibrium equations are:

[0113] F c +F s =0;

[0114] S54. Assuming the cross-section reaches its limit condition, calculate the bearing capacity of the cross-section using the following formula:

[0115] M c =F s H

[0116] Among them, M c The bearing capacity of the cross section is calculated, where H is the lever arm.

[0117] Step S3 specifically includes:

[0118] The flange plate overturning performance evaluation system was fixed on the test bench using a fixing device, and a loading test was performed on the flange plate overturning performance evaluation system.

[0119] The loading test consists of 5 loading cycles. The first loading cycle is the initial loading cycle, which is used to determine the cracking load of the model specimen.

[0120] The maximum values ​​in the second, third, and fourth loading cycles are the maximum values ​​in the design load combination cases, which are used to evaluate the structural stability.

[0121] The fifth loading cycle loads the specimen to the final failure state, and the maximum load value is the test bearing capacity of the structure.

[0122] The loading priority procedure for the overturning resistance test of the concrete T-beam flange plate in this embodiment is as follows: The load level during the loading process of the model specimen can be classified according to three factors: design load, cracking load, and ultimate load under different load combinations, as shown in the table below:

[0123]

[0124]

[0125]

[0126] The flange plate overturning resistance assessment system includes a retaining wall, two flange plate structures, a support structure, ancillary structures, and anchor bolts. The two flange plate structures are located on both sides of the ancillary structures. The anchor bolts are vertically installed through the ancillary structures for fixing them. The retaining wall is vertically located on the outer edge of the flange plate structures. The support structure is located on the outer side of the retaining wall. The reinforcement configuration, dimensions, and materials of the flange plate structures and the support structure are consistent with the flange plate to be tested. The longitudinal length of the retaining wall, the longitudinal length of the flange plate structures, the longitudinal length of the support structure, and the longitudinal length of the ancillary structures are all the sum of the length of the embedded parts being 1 times the longitudinal length and 2 times the vertical height.

[0127] In this embodiment, the simply supported beam is 32.6m long, the longitudinal spacing between the embedded parts and the support is 2m, and the longitudinal spacing between the transverse joints of the retaining wall is 6m.

[0128] The auxiliary structure is added to complete the model loading; its size and configuration can be determined according to the actual test conditions. The loading system is the device for loading the model specimen and simulating the overturning load on the structure; it can be determined according to the actual test conditions. The fixing device is the device for fixing the model specimen to the test pedestal; it can be determined according to the actual test conditions. The test plan is the method for loading and testing the model specimen, determined according to the design load and structural characteristics of the T-beam flange plate structure. The longitudinal length of each of the above components is the sum of the longitudinal length of the embedded T-steel and twice its height as the longitudinal length of the model specimen. If the transverse joint spacing of the retaining wall is less than the calculated value of the longitudinal length, the minimum joint spacing of the retaining wall shall be selected as the longitudinal length of the model specimen. The maximum load that the loading system can apply should be more than three times the design load of the T-beam flange plate structure, and the load values ​​should be able to be recorded.

[0129] The flange plate overturning performance evaluation system should be made in three parts using the same manufacturing process and tested under the same conditions. The arithmetic mean of the maximum load measurements of the three model specimens should be taken as the bearing capacity value of the group of specimens (accurate to 0.1kN). If the difference between the maximum or minimum value and the median value among the three maximum load measurements exceeds 15% of the median value, then the maximum and minimum values ​​should be discarded and the median value should be taken as the test load value of the group of specimens. If the difference between the maximum and minimum values ​​and the median value both exceed 15% of the median value, then the test results of the group of model specimens are invalid.

[0130] The loading test also measured displacement, steel strain, concrete strain, and crack span.

[0131] The first section is the inner surface plane of the retaining wall, the second section is the vertical plane at the flange plate connection, and the third section is the horizontal section at the root of the retaining wall.

[0132] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for evaluating the overturning resistance of a flange plate, characterized in that: Includes the following steps: S1. Evaluate the structural status of the flange plate to be tested to determine whether the current flange plate needs to undergo an anti-overturning test. If yes, proceed to step S2; otherwise, output the structural status of the flange plate. S2. Construct a flange anti-overturning performance evaluation system based on the original flange structure; S3. Perform a loading test on the flange plate overturning performance evaluation system and record the test bearing capacity as an evaluation parameter; S4. Select the section with the largest load as the first check section, select the section with the smallest cross-sectional size as the second check section, and select the section with significant changes in cross-section and stress concentration as the third check section. S5. Calculate the bearing capacity M according to the longitudinal unit section of each check section; S6, calculate the bearing capacity M c With test bearing capacity M t Compare the values ​​and take the smaller value as the structural bearing capacity M; S7. Calculate the internal force values ​​at each key section of the flange plate according to the various self-weights and wind loads specified in the beam structure design code, and use these as the design load internal force M. d ; S8. Divide the structural bearing capacity obtained from the analysis by the internal force of the design load to obtain the safety factor of the check section, as shown in the following formula: Where n is the safety factor; M i Let M be the bearing capacity of section i; di Design the internal forces of the load on section i; S9. Based on the overturning resistance evaluation level corresponding to the obtained safety factor, the overturning resistance status of the flange structure is obtained.

2. The method for evaluating the overturning resistance of a flange plate according to claim 1, characterized in that: The structural condition assessment in step S1 specifically includes: visual inspection, crack detection, and reinforcement protective layer thickness testing of the flange plate to be tested. The specific evaluation method for the visual inspection is as follows: Where R1 is the damage coefficient of visual inspection, T1 is the tilt angle of the retaining wall, T2 is the damaged area of ​​the key inspection area, M1 is the tilt limit value of the retaining wall, and M2 is the total area of ​​the key inspection area. The specific evaluation method for crack detection is as follows: Where R2 is the damage coefficient for crack detection, H1 is the longitudinal length of the crack in the key inspection area, H2 is the crack width in the key inspection area, K1 is the total longitudinal length of the flange plate inspection area, and K2 is the limit value of the crack width of the T-beam flange plate structure. The specific evaluation method for the test of the thickness of the concrete cover for the reinforcing steel is as follows: Wherein, R3 is the damage coefficient of the concrete cover thickness test, F1 is the test value of the concrete cover thickness of the upper transverse reinforcement of the flange slab in the key inspection area, F2 is the design value of the concrete cover thickness of the upper transverse reinforcement of the flange slab in the key inspection area, and P is the over-thickness limit value of the concrete cover thickness of the upper transverse reinforcement of the flange slab in the key inspection area. The formula for calculating the state result R of the concrete T-beam flange plate structure is as follows: Where Pi is the dynamic weighting weight of the detection system, which shows the impact of key indicators on the structural state through dynamic weighting; Ri is the damage coefficient of each detection system. Based on the state result R of the concrete T-beam flange plate structure, a conclusion can be drawn as to whether the current flange plate needs to undergo an anti-overturning test.

3. The method for evaluating the overturning resistance of a flange plate according to claim 1, characterized in that: Step S5 specifically includes: S51. Based on the plane section assumption of strain, calculate the corresponding stress using the following formula: s c =e c E c s s =e s E s Where, σ c For concrete stress; ε c E represents the concrete strain. c For concrete elastic modulus; σ s For the stress of the reinforcing steel; ε s E represents the strain of the reinforcing steel. s For the elastic modulus of the steel reinforcement; S52. The cross-section is calculated based on the stress at various points, determining the stress on the reinforcing steel and concrete within the cross-section. F c =s c A c F s =s s A s Among them, F c For concrete bearing the load; A c For concrete area; F s For the reinforcement to bear the force; F s The area of ​​the reinforcing steel bars; S53. Obtain the forces and lever arms H of the concrete and steel reinforcement based on the equilibrium equations, where the equilibrium equations are: F c + F s ＝0； S54. Assuming the cross-section reaches its limit condition, calculate the bearing capacity of the cross-section using the following formula: M c =F s H Among them, M c The bearing capacity of the cross section is calculated, where H is the lever arm.

4. The method for evaluating the overturning resistance of a flange plate according to claim 1, characterized in that: Step S3 specifically includes: The flange plate overturning performance evaluation system was fixed on the test bench using a fixing device, and a loading test was performed on the flange plate overturning performance evaluation system. The loading test consists of 5 loading cycles. The first loading cycle is the initial loading cycle, which is used to determine the cracking load of the model specimen. The maximum values ​​in the second, third, and fourth loading cycles are the maximum values ​​in the design load combination cases, which are used to evaluate the structural stability. The fifth loading cycle loads the specimen to the final failure state, and the maximum load value is the test bearing capacity of the structure.

5. The flange plate overturning performance evaluation system according to claim 1, characterized in that: The system includes a retaining wall, two flange plate structures, a support, ancillary structures, and anchor bolts. The two flange plate structures are located on both sides of the ancillary structures. The anchor bolts are vertically installed through the ancillary structures for fixing them. The retaining wall is vertically located on the outer side of the flange plate structures. The support is located on the outer side of the retaining wall. The reinforcement configuration, dimensions, and materials of the flange plate structures and the support are consistent with those of the flange plate to be tested. The longitudinal length of the retaining wall, the longitudinal length of the flange plate structures, the longitudinal length of the support, and the longitudinal length of the ancillary structures are all the sum of the length of the embedded part being 1 times its longitudinal length and 2 times its vertical height.

6. The method for evaluating the overturning resistance of a flange plate according to claim 4, characterized in that: The loading test also detects displacement, steel bar strain, concrete strain, and crack span.

7. The method for evaluating the overturning resistance of a flange plate according to claim 1, characterized in that: The first is the inner surface plane of the retaining wall, the second check section is the vertical plane at the flange plate connection, and the third check section is the horizontal section at the root of the retaining wall.

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