CN-115389177-B - Method and system for evaluating anti-overturning performance of flange plate

Abstract

The invention discloses a flange plate anti-overturning performance evaluation method and system, comprising a concrete T-beam flange plate structure state comprehensive evaluation method, a flange plate anti-overturning test model size and parameter, a test method and an evaluation method. The test and evaluation method can evaluate the damage state and the anti-overturning performance of the existing concrete T-beam flange structure, and ensure the safety of the T-beam flange structure in operation.

Inventors

• HU SUOTING
• Dou Junpeng
• XU JIANCHAO
• MA HUIJUN
• SHI LONG
• CHEN SHENGLI
• DONG LIANG
• WANG LERAN
• LI KEBING
• WANG YIGAN
• LI WANGWANG
• SU YONGHUA
• BAN XINLIN
• LIU WENJIAN
• YANG XINYI
• ZHAO TIBO
• RONG JIAO
• WANG WEI

Assignees

• 中国铁道科学研究院集团有限公司
• 中国铁道科学研究院集团有限公司铁道建筑研究所
• 中国国家铁路集团有限公司

Dates

Publication Date

20260505

Application Date

20220706

Claims (7)

1. 1. The flange plate anti-overturning performance evaluation method is characterized by comprising the following steps of: S1, evaluating the structural state of a flange plate to be tested, determining whether the current flange plate needs to be subjected to an anti-overturning test, if so, performing a step S2, otherwise, outputting the structural state of the flange plate; S2, constructing a flange plate anti-overturning performance evaluation system according to the original flange plate structure; S3, carrying out a loading test on the flange plate anti-overturning performance evaluation system, and recording test bearing capacity as an evaluation parameter; S4, selecting a maximum section for bearing the load as a first checking section, selecting a minimum section with a section size as a second checking section, and selecting a section with obvious change and a section for generating stress concentration as a third checking section; S5, respectively calculating bearing capacity M according to the longitudinal unit sections of the detection sections; S6, comparing the calculated bearing capacity M c with the test bearing capacity M t , and taking a smaller value as the structural bearing capacity M; S7, calculating internal force values of key sections of the flange plates according to the dead weights, wind loads and the like born by the beam body structural design specifications, and taking the internal force values as design load internal force M d ; S8, dividing the structural bearing capacity obtained by analysis and the design load internal force to obtain a detection section safety coefficient, wherein the formula is as follows: Wherein n is a safety coefficient, M i is i section bearing capacity, M di is i section design load internal force; S9, obtaining the anti-overturning state of the flange plate structure according to the anti-overturning evaluation grade corresponding to the obtained safety coefficient.
2. 2. The method for evaluating the anti-overturning performance of the flange plate according to claim 1, wherein the structural state evaluation in the step S1 specifically comprises the steps of performing appearance inspection, crack detection and reinforcement protection layer thickness test on the flange plate to be tested respectively; The specific evaluation method of the appearance inspection comprises the following formula: Wherein R1 is a damage coefficient of appearance inspection, T1 is an inclination angle of the ballast blocking wall, T2 is a damage area of a key inspection area, M1 is an inclination limit value of the ballast blocking wall, and M2 is a total area of the key inspection area; the specific evaluation method for crack detection comprises the following specific formula: Wherein R2 is a damage coefficient of crack detection, H1 is the longitudinal length of a crack of a key inspection area, H2 is the width of the crack of the key inspection area, K1 is the longitudinal total length of the inspection area of the flange plate, and K2 is the limit value of the width of the crack of the flange plate of the T beam; The concrete evaluation method for the thickness test of the reinforcement protection layer comprises the following formula: Wherein R3 is a damage coefficient of the thickness test of the reinforcement protection layer, F1 is a thickness test value of the upper layer of the transverse reinforcement protection layer of the flange plate of the important inspection area, F2 is a thickness design value of the upper layer of the transverse reinforcement protection layer of the flange plate of the important inspection area, and P is an ultra-thick limit value of the thickness of the upper layer of the transverse reinforcement protection layer of the flange plate of the important inspection area; and calculating a state result R of the concrete T-beam flange structure, wherein the formula is as follows: pi is the dynamic weighting weight of the detection system, and the influence of the key indexes of the connection structure on the structural state is displayed through dynamic weighting; and (3) obtaining a conclusion whether the current flange plate needs to be subjected to an anti-overturning test according to the state result R of the concrete T beam flange plate structure.
3. 3. The flange plate anti-overturning performance evaluation method according to claim 1, characterized by comprising the steps of: The step S5 specifically includes: s51, according to the assumption of the strain flat section, calculating corresponding stress, wherein the formula is as follows: σ c ＝ε c E c σ s ＝ε s E s Wherein sigma c is concrete stress, epsilon c is concrete strain, E c is a concrete elastic die, sigma s is steel bar stress, epsilon s is steel bar strain, and E s is steel bar elastic die; s52, calculating the stress of the reinforced bars and the concrete in the section according to the stress of the sections, F c ＝σ c A c F s ＝σ s A s Wherein F c is the concrete stress, A c is the concrete area, F s is the steel bar stress, and F s is the steel bar area; s53, obtaining the stress and the force arm H of the concrete and the steel bars according to a balance equation, wherein the balance equation is as follows: F c + F s =0; s54, assuming that the section reaches the limit, calculating the bearing capacity of the section, wherein the formula is as follows: M c ＝F s H Wherein M c is the section calculation bearing capacity, and H is the acting force arm.
4. 4. The flange plate anti-overturning performance evaluation method according to claim 1, characterized by comprising the steps of: the step S3 specifically includes: fixing the flange plate anti-overturning performance evaluation system on a test pedestal through a fixing device, and carrying out a loading test on the flange plate anti-overturning performance evaluation system; the loading test loading process is 5 cyclic loading processes, and the 1 st cyclic loading process is an initial loading cycle and is used for determining the cracking load of the model test piece; The maximum value of the 2 nd, 3 rd and 4 th cyclic loading processes is the maximum value in the design load combination working condition and is used for evaluating the stability of the structural state; and 5, loading the test piece to a final damage state in the cyclic loading process, and taking the maximum load value as the test bearing capacity of the structure.
5. 5. The flange plate anti-overturning performance evaluation system is characterized by comprising a ballast blocking wall, two flange plate structures, a support, an auxiliary structure and an anchor bolt, wherein the two flange plate structures are arranged on two sides of the auxiliary structure, the anchor bolt vertically penetrates through the auxiliary structure to be used for fixing the auxiliary structure, the ballast blocking wall is vertically arranged on the outer side edge part of the flange plate structure, the support is arranged on the outer side of the ballast blocking wall, the reinforcement configurations, the external dimensions and the materials of the flange plate structures and the support are consistent with those of the flange plate to be detected, and the longitudinal length of the ballast blocking wall, the longitudinal length of the flange plate structures, the longitudinal length of the support and the longitudinal length of the auxiliary structure are all the sum of 1 time of the longitudinal length and 2 times of the length of the embedded part.
6. 6. The method for evaluating the anti-overturning performance of the flange plate as claimed in claim 4, wherein the loading test is used for detecting displacement values, steel bar strains, concrete strains and crack spans.
7. 7. The method for evaluating the anti-overturning performance of the flange plate according to claim 1, wherein the first plane is the inner surface plane of the ballast blocking wall, the second detection section is the vertical plane at the joint of the flange plate, and the third detection section is the horizontal section of the root part of the ballast blocking wall.

Description

Method and system for evaluating anti-overturning performance of flange plate Technical Field The invention relates to the field of reinforcement of concrete beam full-scale model tests, in particular to a flange plate anti-overturning performance evaluation method and system. Background The concrete T-beam is a simple beam structure form widely applied to domestic and foreign railways, highways and municipal roads, can exert good material performance of concrete and stress performance of the beam structure form, and is a structure form with good technical economy. The railway bridge in China is mainly a prestressed concrete girder bridge, has definite structural form stress and simple structure, and can provide enough rigidity and stability for train operation. The prestressed concrete T-beam has the advantages of high bearing capacity, less material consumption, small dead weight, good stability, convenient construction and erection, and the like, is a typical beam structure form in bridge construction, and has wide application in railway bridges. The railway bridge concrete T-beam structure is provided with the vertical blocking ballast wall at the transverse beam end of the T-beam, so that railway ballasts can be fixed in a certain range below the steel rail, and a train can stably run for a long time. In railway operation, periodic vibration and noise are generated due to interaction between trains, bridges and tracks, so that when the railway bridges pass through villages, cities and other resident areas, noise-proof devices are required to be arranged. The concrete T beam is provided with a sound barrier device outside the beam body flange plate, and loads such as self weight, pedestrians, wind pressure and the like of the structure are transmitted to the ballast blocking wall and the flange plate through the bracket and the embedded T steel. The sound barrier of the simply supported T beam bears live load effects such as wind load, train aerodynamic force and the like in the railway operation process, and the sound barrier in coastal areas needs to consider typhoon load effects. The flange plate of the sound barrier simply supported T beam for bearing the load is of a thin plate structure, and the structural stress mode of the flange plate is greatly different from the theoretical calculation mode. The root of the blocking ballast wall is a right-angle stress concentration zone, the flange of the blocking ballast wall is of a thin plate structure, so that cracks appear in the structure too early after the structure bears the load, the tensile property of the reinforcing steel bar cannot be exerted, and the durability and ultimate bearing capacity of the structure are reduced. Therefore, the anti-overturning capability of the concrete T-beam flange structure is required to be evaluated, and the safe use of the concrete bridge structure is ensured. On the other hand, as the construction range of the concrete beam structure is wider and wider, and the operation service time is continuously increased, part of bridges are degraded and damaged, so that evaluation and analysis are required to be carried out on the anti-overturning performance of the concrete T beam flange plate, and the operation safety of the beam structure is ensured. In railway operation, accidents such as line interruption and the like are caused by the fact that the flange plate structure and the ballasted wall are cracked at the joint and the ballasted wall falls off as a whole due to various load actions. The intersection of the railway line and the highway line is crossed by adopting a bridge structure, and the falling of the ballast blocking wall has a high probability of causing personal and property accidents. However, at present, no method for performing state evaluation on a concrete T-beam flange plate structure exists, and an anti-overturning test and an analysis method for the flange plate structure of the concrete T-beam flange plate structure are lacked, so that test evaluation and calculation analysis are required to be performed on the concrete T-beam flange plate structure to ensure the operation safety of the concrete T-beam flange plate structure and avoid major safety accidents of the bridge flange plate structure. In order to solve the problems, an anti-overturning performance evaluation method for the flange plate is needed. Disclosure of Invention The invention provides a flange plate anti-overturning performance evaluation method, which aims at solving the problems that a method for evaluating the state of a concrete T-beam flange plate structure is not available in the prior art, and a flange plate structure anti-overturning test and analysis method of the concrete T-beam flange plate structure are lacked, so that test evaluation and calculation analysis are needed to be performed on the concrete T-beam flange plate structure to ensure the operation safety of the concrete T-beam flange plate structure and avoid