A method and system for evaluating old continuous rigid frame bridges in service

Abstract

The present invention relates to the field of bridge engineering inspection and evaluation, and specifically to an evaluation method and system for old continuous rigid frame bridges in service, the method comprising: establishing a data detection mechanism and a data investigation mechanism related to the old continuous rigid frame bridge in service; obtaining the bridge evaluation data through the data detection mechanism and the data investigation mechanism; the bridge evaluation data comprises original bridge design data, and an original bridge design model is constructed based on the original bridge design data; a bridge status model is constructed according to the original bridge design model and the bridge evaluation data; based on the bridge evaluation data and the bridge status model, the current structure of the old continuous rigid frame bridge in service is evaluated to obtain an evaluation result of the current structure of the bridge. The method solves the problem that there is a lack of analysis of the structure of the old continuous rigid frame bridge in service from an overall perspective, and it is difficult to comprehensively evaluate the old continuous rigid frame bridge in service, resulting in inaccurate evaluation of the old continuous rigid frame bridge in service.

Description

Technical Field

[0001] The invention relates to the field of bridge engineering detection and evaluation, in particular to an evaluation method and system for an old continuous rigid frame bridge in service. Background Art

[0002] In order to ensure the normal operation of old continuous rigid frame bridges in service, conventional surface inspection or non-destructive testing is usually used to understand the structural stress condition of the bridge through the surface condition. However, conventional surface inspection and non-destructive testing often make it difficult to find the root cause of the disease, and it is difficult to analyze the problems that cause the disease in depth, specifically, and quantitatively. In recent years, the development and progress of some new detection technologies, new equipment, and new methods have provided the possibility to analyze the causes and development mechanisms of the diseases of continuous rigid frame bridges in service and evaluate the current status of the structure.

[0003] In addition to routine appearance inspection and assessment, the inspection of old continuous rigid frame bridges in service should also be analyzed from multiple aspects and angles, such as geometric morphology, material condition, mechanical properties, structural system, defects and diseases, and reinforcement and renovation performance, in order to achieve the effect of comprehensive analysis. At present, common special inspections are basically special inspections from a certain point. Although the special inspection of a certain point can reflect the current status of a certain point, the lack of analysis of the structure from a global and overall perspective will inevitably lead to biased judgments on the overall structure, which often leads to the phenomenon of "treating the head for a headache and the foot for a foot pain" during bridge maintenance. How to objectively analyze the overall condition of the bridge structure, obtain the root cause of the bridge disease, and provide a basis for the maintenance and treatment design and reinforcement and renovation design after the inspection has become an engineering problem that needs to be solved urgently in projects such as old bridge maintenance and treatment, old bridge reinforcement and renovation, and bridge expansion and renovation design decisions. Summary of the invention

[0004] In view of the defects in the prior art and the shortcomings in practical applications, the author has invented a method and system for evaluating old continuous rigid frame bridges in service, which solves the related problems of lack of analysis of the structure of old continuous rigid frame bridges in service from a global and overall perspective, and difficulty in comprehensive evaluation of old continuous rigid frame bridges in service, resulting in overly one-sided and overall inaccurate judgment of the overall structure of old continuous rigid frame bridges in service, resulting in the problem of treating the symptoms but not the root cause during the maintenance of old continuous rigid frame bridges in service.

[0005] In order to achieve the above-mentioned purpose, one aspect of the present invention provides a method for evaluating old continuous rigid frame bridges in service, the method comprising: establishing a data detection mechanism and a data investigation mechanism related to the old continuous rigid frame bridge in service; obtaining bridge evaluation data through the data detection mechanism and the data investigation mechanism; the bridge evaluation data comprises original bridge design data, and an original bridge design model is constructed based on the original bridge design data; a bridge status model is constructed according to the original bridge design model and the bridge evaluation data; based on the bridge evaluation data and the bridge status model, the current structure of the old continuous rigid frame bridge in service is evaluated to obtain an evaluation result of the bridge status structure.

[0006] The present invention establishes a data detection mechanism and a data investigation mechanism for the old continuous rigid frame bridges in service, thereby realizing the investigation and detection of the old continuous rigid frame bridges in service, and obtains the corresponding bridge evaluation data through the investigation and detection of the old continuous rigid frame bridges in service, and then constructs a bridge status model, thereby providing a real and objective data basis for subsequent evaluation.

[0007] Optionally, the bridge assessment data is obtained through the data detection mechanism and the data investigation mechanism, including: obtaining bridge investigation data based on the investigation of the old continuous rigid frame bridge in service; obtaining bridge structure damage data based on the detection of the structural damage of the old continuous rigid frame bridge in service; obtaining bridge structure constant load data based on the detection of the structural constant load condition of the old continuous rigid frame bridge in service; obtaining bridge concrete material property data based on the detection of the concrete box girder material properties of the old continuous rigid frame bridge in service; obtaining bridge durability parameter data based on the detection of concrete durability parameters of the old continuous rigid frame bridge in service; obtaining bridge prestressed system data based on the detection of the prestressed system of the old continuous rigid frame bridge in service; obtaining bridge reinforcement measures effectiveness data based on the detection of the effectiveness of reinforcement measures for the old continuous rigid frame bridge in service; obtaining bridge structure stiffness attenuation data based on the self-vibration characteristic test of the upper structure of the old continuous rigid frame bridge in service using the pulsation method; obtaining bridge hidden engineering data based on the detection of pile foundation integrity and pile length of the old continuous rigid frame bridge in service.

[0008] The present invention provides a reliable data source for bridge evaluation by deeply investigating bridge data and making targeted tests on various parts of the bridge, thereby improving the credibility and accuracy of bridge evaluation.

[0009] Optionally, a bridge status model is constructed according to the original bridge design model and the bridge evaluation data, including: obtaining a sensitivity analysis result by performing a sensitivity analysis on the original bridge design model; and based on the sensitivity analysis result and the bridge evaluation data, performing a time-varying effect analysis on the original bridge design model to construct the bridge status model.

[0010] Through sensitivity analysis, the present invention can determine the more sensitive parameters in the finite element model of bridge structure analysis, and provide a basis for parameter correction when constructing the bridge status model. Time-varying effect analysis and evolution process analysis make the bridge status model more in line with the actual situation, thereby improving the practicability of the bridge status model.

[0011] Optionally, constructing a bridge status model based on the original design model of the bridge and the bridge assessment data also includes: obtaining historical cumulative measured deformation data of the old continuous rigid frame bridge in service; performing an evolution process analysis on the bridge status model based on the historical cumulative measured deformation data until the deformation data calculated by the bridge status model reaches a threshold value of consistency with the historical cumulative measured deformation data.

[0012] The present invention further corrects the bridge status model through historical accumulated measured deformation data, so that the bridge status model is more in line with reality, and further improves the practicability of the bridge status model.

[0013] Optionally, based on the bridge assessment data and the bridge status model, the current structure of the in-service old continuous rigid frame bridge is assessed to obtain a bridge status structure assessment result, including: the bridge assessment data includes on-site test data, based on evidence theory, the on-site test data is used to assess the technical condition of the in-service old continuous rigid frame bridge to obtain a bridge technical condition assessment result; the bridge assessment data includes bridge survey data, according to the bridge technical condition assessment result, the on-site test data and the bridge survey data, the structural bearing capacity of the bridge status model is assessed to obtain a bridge structure bearing capacity assessment result; the bridge assessment data includes durability test data, according to the durability test data, the structural durability of the in-service old continuous rigid frame bridge is assessed to obtain a bridge structure durability assessment result; according to the bridge technical condition assessment result, the bridge structure bearing capacity assessment result and the bridge structure durability assessment result, the bridge status structure assessment result is obtained.

[0014] The present invention comprehensively evaluates the technical status, load-bearing capacity and durability of old continuous rigid frame bridges in service, and then integrates the evaluation results of various aspects to obtain the evaluation result of the current structure of the bridge, thereby improving the accuracy of the evaluation of old continuous rigid frame bridges in service.

[0015] Optionally, the method based on evidence theory utilizes the field inspection data to assess the technical condition of the old continuous rigid frame bridges in service to obtain the assessment result of the technical condition of the bridge, including: obtaining the uninspected data of the old continuous rigid frame bridges in service, and setting the uncertainty probability of the uninspected data to 1, setting a grade scale and a first weight for the field inspection data, and obtaining the component assessment result according to the uncertainty probability, the grade scale and the first weight; setting a second weight for the component data, and obtaining the component assessment result according to the component assessment result and the second weight; setting a third weight for the component data, and obtaining the structure assessment result according to the component assessment result and the third weight; and obtaining the bridge technical condition assessment result according to the structure assessment result.

[0016] The present invention simplifies complex problems by evaluating the test data in layers, improves the efficiency of evaluating old continuous rigid frame bridges in service, and takes into account the impact of untested data on the technical condition of bridges. By setting the weight of each sub-item in each layer and using the evidence synthesis rule to obtain the probability of belonging to a certain level, the accuracy of the evaluation results of the technical condition of bridges is improved.

[0017] Optionally, the component assessment result satisfies the following formula:

[0018] ,

[0019] ,

[0020] ,

[0021] ,

[0022] ,

[0023] ,

[0024] in, Indicates the rating result level is The function of Indicates the level The synthesis function of is the normalization constant, Indicates the maximum serial number of a component. Indicates the component number. Representation component Rated as level The probability function of is the probability of uncertainty in level due to incomplete information. represents the probability that the level is uncertain due to the weight of the field detection data on the component data, Indicates that the evaluation result level is an uncertain function. represents a probability function of uncertainty in level caused by the weight of the field detection data on the component data, represents the probability function of uncertainty in level due to incomplete information. Indicates the highest rating. Indicates the grade after synthesis is The probability of It indicates the probability that the grade after synthesis is uncertain.

[0025] The formula of the present invention fully considers the influence of weight and uncertain information on the evaluation result, so that the evaluation result is more rigorous and the accuracy of the evaluation is improved.

[0026] Optionally, the structural bearing capacity of the current bridge model is assessed according to the bridge technical condition assessment result, the on-site test data and the bridge survey data to obtain the bridge structure bearing capacity assessment result, including: performing structural verification on the current bridge model according to the bridge technical condition assessment result, the on-site test data and the bridge survey data; and assessing the structural bearing capacity of the current bridge model based on the result of the structural verification to obtain the bridge structure bearing capacity assessment result.

[0027] The present invention evaluates the structural bearing capacity of the old continuous rigid frame bridge in service by means of structural verification based on the current status model of the bridge, and fully considers the influence of the technical status of the bridge and the data of the bridge itself on the structural bearing capacity, thereby improving the accuracy of the evaluation result of the bridge structure bearing capacity.

[0028] Optionally, the structural bearing capacity of the current status model of the bridge is assessed according to the assessment results of the technical condition of the bridge, the on-site inspection data and the bridge survey data to obtain the assessment results of the structural bearing capacity of the bridge, including: obtaining load test data based on the load test of the old continuous rigid frame bridge in service; assessing the structural bearing capacity of the current status model of the bridge according to the assessment results of the technical condition of the bridge, the on-site inspection data and the bridge survey data using the load test data to obtain the assessment results of the structural bearing capacity of the bridge.

[0029] The present invention further improves the accuracy of the bridge structure bearing capacity assessment result by conducting a load test on an old continuous rigid frame bridge in service, and combining the bridge status model, bridge technical condition assessment result, on-site test data and bridge investigation data.

[0030] Another aspect of the present invention provides a system for evaluating old continuous rigid frame bridges in service, the system comprising: a processor, an input device, an output device and a memory, the processor, the input device, the output device and the memory being interconnected, wherein the memory is used to store a computer program, the computer program comprising program instructions, the processor being configured to call the program instructions to execute a method for evaluating old continuous rigid frame bridges in service as described in any one of the previous aspects of the present invention.

[0031] The present invention provides an in-service old continuous rigid frame bridge evaluation system with compact structure, stable performance, high integration and simple composition. It can stably execute an in-service old continuous rigid frame bridge evaluation method provided by the previous aspect of the present invention, further improving the overall applicability and practical application capability of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A flow chart of an evaluation method for an old continuous rigid frame bridge in service according to an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of the structure of an evaluation system for an old continuous rigid frame bridge in service according to an embodiment of the present invention; DETAILED DESCRIPTION

[0034] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not need to be adopted to implement the present invention. In other examples, in order to avoid confusing the present invention, known circuits, software or methods are not specifically described.

[0035] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or subcombination. In addition, it should be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale.

[0036] See also Figure 1In order to solve the related problems of lack of analysis on the structure of old continuous rigid frame bridges in service from a global and overall perspective, and difficulty in comprehensive evaluation of old continuous rigid frame bridges in service, which leads to overly one-sided and overall inaccurate judgment on the overall structure of old continuous rigid frame bridges in service, and the problem of treating the symptoms but not the root cause in the maintenance of old continuous rigid frame bridges in service, various on-site measurements of old continuous rigid frame bridges in service were carried out, and combined with the investigation of old continuous rigid frame bridges in service, factors such as the design of old continuous rigid frame bridges in service and the traffic flow of old continuous rigid frame bridges in service were included in the evaluation scope, so as to achieve a comprehensive evaluation of old continuous rigid frame bridges in service.

[0037] Figure 1 FIG. 1 is a flow chart of an evaluation method for an old continuous rigid frame bridge in service according to an embodiment of the present invention. Figure 1 The method shown includes the following steps:

[0038] Step S1, establishing a data detection mechanism and a data investigation mechanism related to the old continuous rigid frame bridge in service. The data detection mechanism refers to a targeted detection of various parts of the bridge.

[0039] In this embodiment, the data investigation mechanism includes an investigation of technical data of old continuous rigid frame bridges in service and an investigation of traffic flow.

[0040] Step S2, obtaining bridge assessment data through the data detection mechanism and the data investigation mechanism.

[0041] Wherein, obtaining bridge assessment data through the data detection mechanism and the data investigation mechanism specifically includes the following sub-steps:

[0042] Step S201, based on the survey of the old continuous rigid frame bridge in service, bridge survey data is obtained.

[0043] In this embodiment, the inspection and evaluation of the old continuous rigid frame bridge in service first needs to investigate the data and obtain the bridge investigation data. The main contents of the data investigation include the original design data, important historical event data during the construction period, maintenance period inspection and maintenance data, traffic flow data, etc. The technical data can provide data support for the determination of subsequent inspection content and the selection of inspection sites, and the traffic flow survey can provide basic data for the analysis of the causes of diseases, the assessment of bearing capacity, and the evaluation of bridge applicability.

[0044] Step S202: obtaining bridge structure damage data based on the detection of the structural damage of the old continuous rigid frame bridge in service.

[0045] In this embodiment, a comprehensive inspection of the apparent cracks is carried out by setting up an inspection platform inside the box, and a detailed and comprehensive inspection of the apparent cracks of the old continuous rigid frame bridge in service is carried out. The distribution, direction, width and other characteristics of the cracks are analyzed, and compared with the weak links in the structure.

[0046] The core sampling method was used to investigate the crack depth of typical structural cracks.

[0047] The coring method is a method to directly obtain samples from the interior of the concrete of old continuous rigid frame bridges in service, and is used to investigate relevant information such as the depth of cracks in old continuous rigid frame bridges in service. It uses a special coring drill to drill concrete core samples from representative parts of the structure of old continuous rigid frame bridges in service. These core samples can intuitively reflect the structural conditions inside the concrete, including the depth of cracks, the density of concrete, and the distribution of aggregates.

[0048] The core drilling rig is generally composed of a power part, a drill rod, a drill bit and other components. During operation, the location and direction of coring are determined according to the needs, the drill bit is aimed at the target position, and after the drilling rig is started, the drill bit cuts into the concrete under the action of rotation and axial pressure, gradually forming a cylindrical core sample.

[0049] The selection of the coring location is crucial, and it is necessary to comprehensively consider the structural characteristics of the old continuous rigid frame bridge in service, the location and direction of the cracks, and other factors. Generally, it is preferred to coring near the widest and most representative part of the crack. For example, if a crack appears in the mid-span of a beam bridge, and the crack direction is vertical, then the coring location can be determined near the mid-span and along the direction of the crack, so as to obtain the most information related to the crack depth.

[0050] At the same time, it is also necessary to avoid coring in key stress-bearing parts of the structure (such as the main reinforcement position in the tension zone of the beam) or areas that may affect the structural safety of old continuous rigid frame bridges in service. For prestressed concrete bridges, special attention should be paid to not damaging the prestressed tendons, otherwise it may cause prestress loss and affect the bearing capacity of old continuous rigid frame bridges in service.

[0051] Select individual typical structural cracks to track and observe crack activity and analyze the factors affecting crack activity. Crack activity tracking observation can be carried out using a strain sensor or a micrometer-clamp combination device.

[0052] The principle of using strain sensors to track and observe crack activity is that when a crack is active, such as a change in crack width, the strain sensors attached to both sides of the crack will produce strain changes due to the stretching or compression of the crack. Taking the resistance strain gauge as an example, as mentioned above, it is based on the resistance strain effect. When the structures on both sides of the crack are relatively displaced, the strain gauge deforms accordingly, causing its resistance value to change. By converting the resistance change into an electrical signal through a measuring circuit, strain information related to the change in crack width can be obtained. Optical fiber strain sensors also work on a similar principle. When crack activity causes the optical fiber to deform, the light propagation characteristics in the optical fiber change. For example, the fiber Bragg grating (FBG) sensor reflects the activity of the crack by detecting changes in the wavelength of the reflected light.

[0053] The method of using strain sensors to track crack activity is to paste strain sensors at appropriate locations on both sides of the crack. First, the pasting surface must be processed to ensure that it is flat, dry and oil-free. For resistance strain gauges, use suitable glue (such as epoxy resin) to firmly paste them on both sides of the crack, ensuring that the direction of the sensitive grid of the strain gauge is consistent with the expected crack activity direction. For fiber optic strain sensors, pay attention to the laying path of the optical fiber to avoid additional damage to the optical fiber. After installation, connect the strain sensor to the data acquisition system to record strain data in real time. By analyzing the data, the change pattern of the crack width can be obtained, such as whether the crack is in a state of continuous expansion, stability or contraction.

[0054] The principle of using the combination of micrometer and fixture to track and observe crack activity is that the micrometer is a high-precision length measuring tool. Its working principle is to convert the linear displacement of the measuring rod into the angular displacement of the pointer through the transmission of gears and racks, thereby displaying a small length change on the dial. When used for tracking and observing crack activity, the fixtures are fixed on both sides of the crack, and the measuring rod of the micrometer is connected to one side of the fixture. When the crack is active, the relative displacement on both sides of the crack will be transmitted to the measuring rod of the micrometer, causing the micrometer pointer to rotate, thereby intuitively displaying the change in the crack width.

[0055] The method of using the dial gauge-clamp combination device to track and observe crack activity is to ensure that the clamp can be firmly fixed to the structural surface on both sides of the crack when installing the clamp. It is usually fixed by bolts or glue. For different structural materials (such as concrete, masonry, etc.), it is necessary to choose a suitable fixing method. For example, on a concrete structure, you can drill holes first and then use expansion bolts to fix the clamp. After installing the dial gauge on the clamp, set the initial reading of the dial gauge and record the initial width of the crack. In the subsequent observation process, read the value of the dial gauge regularly, and obtain the change in the crack width by comparing it with the initial reading. At the same time, pay attention to protecting the dial gauge from external factors (such as collision, dust, moisture, etc.) to ensure the accuracy of the measurement.

[0056] The construction segment joints are the weak link in the quality of the concrete of the superstructure of the continuous rigid frame bridge. The ultrasonic testing method is used to investigate the quality of the construction segment joints of the box girder.

[0057] Ultrasonic testing is a method of detecting the internal structure and defects of an object by using the differences in the propagation characteristics of ultrasound in different media. When ultrasound propagates in concrete, it will be reflected, refracted, scattered and attenuated due to the density of the medium, internal defects and other conditions. For the joints of box girder construction segments, when ultrasound encounters the joint interface, if the joint quality is good, the ultrasound will propagate and reflect according to certain rules. If there are defects in the joint, such as gaps, voids, looseness, etc., the parameters such as the propagation path of the ultrasound, the intensity of the reflected wave and the propagation time will change.

[0058] First, select an instrument with a suitable frequency range and accuracy. The frequency range of ultrasonic detectors generally used for concrete testing is between 20-200kHz, and it is necessary to ensure that the instrument has stable performance, strong signal processing capabilities, and can accurately measure ultrasonic propagation time, amplitude and other parameters. Before testing, the instrument should be calibrated, and standard test blocks should be used to adjust the instrument's sound velocity, gain and other parameters to ensure the accuracy of the measurement. Then select the probe according to the characteristics of the box girder segment joint. The probe frequency is generally between 50-100kHz, and the probe diameter is usually 20-30mm. For plane joints, straight probes are more suitable. If you want to detect joints with inclined angles or internal defects near joints, you can use oblique probes. At the same time, prepare a sufficient number of probes to meet the detection needs of different locations.

[0059] Before starting the test, clean the surface of the joints of the box girder construction sections to remove impurities such as oil, rust, and loose concrete. These impurities will affect the transmission of ultrasonic waves, resulting in inaccurate test results. Grind the surface of the test area to make it flat and smooth to ensure good contact between the probe and the concrete surface. If the surface is not flat, an air layer will form between the probe and the concrete, and the air has a high reflectivity to ultrasonic waves, which will hinder the normal propagation of ultrasonic waves.

[0060] Turn on the ultrasonic detector and measure the propagation time, amplitude, frequency and other parameters of the ultrasonic wave in the concrete segments and joints. The propagation time refers to the time it takes for the ultrasonic wave to travel from the transmitting probe to the receiving probe, which is related to the propagation path length and speed of the ultrasonic wave. The amplitude refers to the amplitude of the received signal, which reflects the energy attenuation of the ultrasonic wave during the propagation process. The frequency is the frequency characteristic of the received signal. When the ultrasonic wave encounters different media or defects, the frequency may change. For each inspection point, these parameters should be recorded in detail. You can use a spreadsheet or special inspection software to record them to ensure the integrity and accuracy of the data.

[0061] For areas where the apparent condition of old continuous rigid frame bridges in service is defective, ultrasonic method and core sampling verification method are used to investigate the internal defects of concrete.

[0062] By measuring the structural deck alignment of old continuous rigid frame bridges in service and comparing and analyzing it with historical data, we can obtain the time-varying deflection curve of old continuous rigid frame bridges in service.

[0063] According to the actual conditions of the old continuous rigid frame bridges in service, the deviation of the bridge piers is measured. The deviation measurement of the bridge piers should be carried out using the laser plumb line method or the total station measurement method.

[0064] The laser vertical line method utilizes the characteristics of laser, such as good directionality, concentrated energy and good monochromaticity. The basic principle is to set a laser emitting device on the top of the bridge pier, so that the laser beam is emitted vertically downward, and a receiving device is set at the bottom of the bridge pier. Since the laser beam is vertical, if the bridge pier is not offset, the laser point should fall on the predetermined center position of the receiving device; if the bridge pier is offset, the laser point will deviate from the center position, and the deviation of the bridge pier can be determined by measuring this deviation. For example, assuming that the laser emitted by the laser emitting device is vertically downward, and the receiving device is a flat target with a scale, when the bridge pier is in the ideal position, the laser point falls on the center of the target. If the bridge pier is offset in the horizontal direction, the laser point will produce a horizontal displacement on the target surface. By reading the scale value corresponding to this displacement, the deviation value of the bridge pier in this direction can be obtained.

[0065] The bridge assessment data includes bridge survey data and on-site inspection data, wherein the bridge survey data includes technical data data and traffic flow data, the technical data data includes original design data, important historical event data during the construction period, and inspection and repair data during the maintenance period, and the on-site inspection data includes bridge structure damage data, bridge structure constant load data, bridge concrete material property data, bridge durability parameter data, bridge prestressed system data, bridge reinforcement measures effectiveness data, and bridge structure stiffness attenuation data.

[0066] Step S203, based on the detection of the structural dead load condition of the old continuous rigid frame bridge in service, the bridge structure dead load data is obtained.

[0067] In this embodiment, a three-dimensional laser scanner is used to scan the geometric shape of the old continuous rigid frame bridge in service, and the result is nested with the scanning result inside the superstructure box to obtain a point cloud model of the old continuous rigid frame bridge in service. The point cloud model is used to analyze the cross-sectional dimensions of the box girder to obtain the actual geometric dimensions of each construction section. The constant load mass of the structure can be calculated through the geometric dimensions and the concrete density measured by the coring method.

[0068] The 3D laser scanning results are verified by local measurement, and the scanned geometric dimensions are corrected, thereby eliminating the measurement result errors caused by the long distance of the 3D laser scanning.

[0069] The constant load data of the bridge structure is obtained through the constant load condition survey, and the estimated correction amount of the constant load condition at each construction stage is obtained, which can be used to correct the original design model of the bridge. The theoretical correction coefficient is shown in the following formula:

[0070]

[0071] Where: is the dead load correction factor for each section; Measure the weight for each segment; Design a theoretical weight for each segment.

[0072] Step S204, based on the detection of the material properties of the concrete box girder of the old continuous rigid frame bridge in service, the bridge concrete material property data is obtained.

[0073] The material properties of the concrete box girder are tested by coring to obtain the bridge concrete material property data. The test items include concrete strength and concrete elastic modulus. The material property correction coefficient is shown in the following formula:

[0074]

[0075] Where: is the correction factor of concrete strength; is the measured concrete strength; To design concrete strength.

[0076]

[0077] In the formula, is the correction factor of concrete elastic modulus, To measure the elastic modulus of concrete, is the design elastic modulus of concrete.

[0078] The measured concrete strength and elastic modulus are important sources of material parameters for establishing the original design model of the bridge.

[0079] Step S205, obtaining bridge durability parameter data based on the detection of concrete durability parameters of the old continuous rigid frame bridge in service.

[0080] The durability parameters of concrete are tested by non-destructive testing methods to obtain bridge durability parameter data. The test items include but are not limited to concrete rebound strength, steel bar protective layer thickness, steel bar corrosion potential, concrete resistivity and concrete chloride ion content.

[0081] The non-destructive testing parameters need to be calibrated according to relevant standards and used for technical condition assessment and load-bearing capacity assessment. The measured durability parameters can be used as the basic parameters for durability assessment.

[0082] Step S206, based on the detection of the prestressed system of the old continuous rigid frame bridge in service, the prestressed system data of the bridge is obtained.

[0083] Longitudinal prestressing generally tests the effective stress of the bottom plate, the density of grouting, and the condition of the anchor head. The effective prestressing of the bottom plate is carried out by the transverse tension method, the density of grouting is carried out by the drilling method, and the condition of the anchor head needs to be opened for inspection to verify whether the current status of the longitudinal prestressing is consistent with the ideal design state.

[0084] The effective stress of the longitudinal prestress is the key to the simulation of the existing structure. Accurately estimating and correcting the effective stress of the longitudinal prestress affects the stress and deflection calculation of the normal use limit of the structure. The effective stress of the longitudinal prestress is corrected according to the following formula:

[0085]

[0086] Where: is the correction factor of effective prestress; is the measured effective stress of each prestressing beam; To control the tensile stress for design; is the theoretically calculated prestress loss stress.

[0087] Transverse prestressing generally tests the grouting density and anchor head condition. The grouting density is tested by drilling method, and the anchor head condition inspection requires opening the anchor head for inspection to verify whether the current state of transverse prestressing is consistent with the ideal design state.

[0088] The vertical prestressing is generally tested for grouting density, which is carried out by drilling method.

[0089] The prestressed system data of the bridge is obtained through the detection of the prestressed system, and the estimated amount of effective prestress loss is obtained, which is used to modify the original design model of the bridge.

[0090] Step S207, based on the effectiveness detection of the reinforcement measures of the old continuous rigid frame bridge in service, obtaining the effectiveness data of the bridge reinforcement measures.

[0091] The effect of reinforcement measures will show a trend of decreasing or deteriorating over time. For bridges that have been reinforced or strengthened, the effectiveness of reinforcement measures should also be tested. Common reinforcement measures include: gluing steel plates, gluing carbon fiber cloth, and tensioning external prestressed tendons.

[0092] For old continuous rigid frame bridges in service that are reinforced with glued steel plates, the effectiveness of the glued steel plates should be tested by the tapping method, and detailed records should be kept of the existence of hollows, falling steel plate strips, rusted steel plates, etc.

[0093] The adhesion of the carbon fiber cloth is checked with a puller to determine the effectiveness of the adhesion of the carbon fiber cloth, and detailed records of the areas where the appearance has fallen off are also required.

[0094] The effective stress of external prestressing needs to be tested to obtain the effectiveness data of bridge reinforcement measures. The testing method can be carried out by transverse tension method or pull-out method.

[0095] The effective stress of external prestressing is also the key to the simulation of the existing structure. The accurate estimation of the effective stress of external prestressing for correction reinforcement affects the stress and deflection calculation of the normal use limit state of the structure. The effective stress of external prestressing is corrected according to the following formula:

[0096]

[0097] In the formula, is the correction coefficient of the effective prestress of the external prestress, is the measured effective stress of each external prestressing beam, To design the external prestressing to control the tensile stress, is the theoretically calculated external prestress loss stress.

[0098] The reinforcement measures effect inspection results can be used to obtain the estimated reduction factor of the reinforcement measures, and the original design model of the bridge can be modified through the reinforcement measures reduction factor.

[0099] Step S208, obtaining bridge structure stiffness attenuation data based on a natural vibration characteristic test of the upper structure of the old continuous rigid frame bridge in service using a pulsation method.

[0100] The pulsation method was used to conduct a self-vibration characteristic test on the upper structure of an old continuous rigid frame bridge in service to obtain the bridge structure stiffness attenuation data. The test results include the natural frequency, vibration mode, and damping ratio. The attenuation of the overall stiffness of the structure is analyzed through the natural frequency test results, and the stiffness attenuation can be used as the basis for the stiffness correction of the original design model of the bridge. The stiffness correction can be performed by correcting the section inertia moment. The correction parameters are shown in the table below.

[0101]

[0102] In the formula, is the upper structure stiffness correction factor, is the current measured natural frequency, It is the natural frequency obtained from the natural vibration characteristic test when the railway was completed and opened to traffic.

[0103] Step S209, based on the detection of the integrity and length of the pile foundation of the old continuous rigid frame bridge in service, the bridge hidden engineering data is obtained.

[0104] Concealed engineering inspection mainly focuses on the integrity and length of pile foundations. The integrity of pile foundations is generally tested by low-strain reflection wave method, and the pile length is generally tested by magnetic logging method. Concealed engineering inspection provides a basis for the treatment of concealed engineering.

[0105] Step S3: the bridge assessment data includes original bridge design data, and an original bridge design model is constructed based on the original bridge design data.

[0106] In this embodiment, the original design model of the bridge is generated by using the original design data of an old continuous rigid frame bridge in service using bridge structure finite element analysis software.

[0107] In an optional embodiment, the original design model of the bridge is generated using ANSYS. As one of the most popular finite element analysis software in the world, ANSYS has multiple functional modules such as structural analysis, thermal analysis, fluid analysis, and electromagnetic analysis. It can be used to solve various complex engineering problems and performs well in the analysis of statics, dynamics, stability, etc. of bridge structures. Users can perform secondary development through the parametric design language APDL to realize customized analysis functions and processes to meet the special needs and personalized analysis of different users.

[0108] ANSYS can build accurate three-dimensional bridge models, taking into account various complex geometric shapes, material properties, boundary conditions and load conditions, and using advanced numerical calculation methods to solve and obtain high-precision analysis results. At the same time, ANSYS also provides a large number of unit types, such as beam units, shell units, solid units, etc., as well as a variety of material constitutive models, which can accurately simulate the mechanical properties of different materials in bridge structures.

[0109] In another optional embodiment, Midas Civil can also be used to generate the original design model of the bridge. Midas Civil integrates visual data processing functions, can intuitively display structural parameters, and is convenient for users to input, edit and view data. It improves work efficiency while fully considering the complex composition and construction conditions of various bridge structures. It pays attention to details and precision in design calculations, and the calculation results are accurate and reliable. It has good analysis effects on various bridge types such as reinforced concrete and prestressed concrete beam bridges, arch bridges, cable-stayed bridges, and suspension bridges.

[0110] Step S4, constructing a bridge status model according to the original bridge design model and the bridge assessment data.

[0111] Wherein, constructing the bridge status model according to the original bridge design model and the bridge assessment data specifically includes the following sub-steps:

[0112] Step S401, performing sensitivity analysis on the original design model of the bridge to obtain sensitivity analysis results.

[0113] In this embodiment, in order to make the bridge status model more consistent with the actual bridge status, it is necessary to perform sensitivity analysis on the main parameters that affect the structural deformation and stress to assist in fitting the status model.

[0114] In an optional embodiment, the finite difference method is used for sensitivity analysis, the principle of which is to make a small perturbation to each sensitivity parameter near its baseline value, calculate the rate of change of the structural performance index caused by the perturbation, and approximate the sensitivity coefficient of the parameter.

[0115] In another optional embodiment, Latin hypercube sampling combined with regression analysis is used for sensitivity analysis. The principle is to first select a large number of sample points within the range of parameter values ​​using Latin hypercube sampling technology, and then perform bridge model calculations on each sample point to obtain the corresponding structural performance index. Finally, a mathematical model between the structural performance index and the sensitivity parameter is established through regression analysis, and the sensitivity of the parameter is judged according to the size of the regression coefficient.

[0116] Step S402: Based on the sensitivity analysis result and the bridge assessment data, a time-varying effect analysis is performed on the original design model of the bridge to construct the current status model of the bridge.

[0117] In this embodiment, in addition to adopting corresponding detection parameter corrections, the establishment of the bridge status model should also consider the influence of time-varying effects. The loading age of each component, reinforcement and maintenance measures, etc. must be simulated according to the actual time history. For the creep model, multiple creep modes can be selected for modeling and analysis separately to analyze the structural evolution law under different creep modes.

[0118] Time-varying effect analysis refers to the analysis of the changes in various mechanical properties of old continuous rigid frame bridge structures in service due to time factors during long-term use. These changes include the deterioration of material properties, changes in structural geometry, and changes in external loads over time, which have a combined effect on the safety, applicability and durability of the structure.

[0119] Step S403, obtaining the historical accumulated measured deformation data of the old continuous rigid frame bridge in service.

[0120] In this embodiment, through an in-depth investigation of bridges, the historical cumulative measured deformation data of old continuous rigid frame bridges in service are obtained.

[0121] Step S404: analyzing the evolution process of the bridge status model according to the historical accumulated measured deformation data, until the deformation data calculated from the bridge status model and the historical accumulated measured deformation data have a matching degree reaching a threshold.

[0122] In this embodiment, for bridges with historical cumulative measured deformation results, the deflection can be calculated based on the current model of the bridge and compared with the historical measured cumulative deflection values ​​of old continuous rigid frame bridges in service. Through the continuous correction and iteration of the theoretical parameters of the bridge, the permanent deformation of the original design model of the bridge in different time periods is obtained, and compared with the permanent deformation history of the measured structure, until the degree of consistency between the theoretical deformation of the bridge and the measured deformation reaches an acceptable range, and then the evolution process of the structure is obtained. The obtained theoretical model of the evolution process can be used to analyze the causes of diseases that occur in different time periods, and a more current original design model of the bridge can be obtained. The current model of the bridge with the evolution process can be used for the ultimate limit state verification of the bearing capacity of the old continuous rigid frame bridge in service under the permanent condition and the ultimate limit state verification of the normal use under the permanent condition.

[0123] For old continuous rigid frame bridges in service without measured deformation results, the existing model of the bridge can be directly used as the benchmark model for the ultimate limit state verification of the bridge's bearing capacity under permanent conditions and the ultimate limit state verification of its normal use under permanent conditions.

[0124] The elastic modulus of concrete has the characteristic of slowly increasing over time. When simulating the current bridge model, it is necessary to simulate according to the actual change in elastic modulus. Since the elastic modulus growth curve varies according to the concrete mix ratio, the elastic modulus value at the key time point can be interpolated in the intermediate time period.

[0125] In general, the 1985 code creep model and the 2004 code creep model are used to model and calculate the theoretical historical cumulative deformation of the bridge according to the bridge loading history, and the influence of factors such as dead load over-square, live load loading, stiffness reduction, and prestress loss on permanent deformation is gradually considered. The theoretical historical cumulative deformation is obtained according to the superposition principle and compared with the measured cumulative deformation. If the fitting result is acceptable, a current status model that conforms to the actual situation can be obtained. If it is unacceptable, the corresponding parameters are adjusted according to the measured results until the difference between the theoretical results and the measured results is within an acceptable range.

[0126] Step S5, based on the bridge assessment data and the bridge status model, assess the current structure of the old continuous rigid frame bridge in service to obtain a bridge current structure assessment result.

[0127] Wherein, based on the bridge assessment data and the bridge status model, the current structure of the old continuous rigid frame bridge in service is assessed, and obtaining the bridge current structure assessment result specifically includes the following sub-steps:

[0128] Step S501, the bridge assessment data includes field test data. Based on evidence theory, the field test data is used to assess the technical condition of the old continuous rigid frame bridge in service to obtain a bridge technical condition assessment result.

[0129] The bridge assessment data includes on-site inspection data. Based on the theory of evidence, the on-site inspection data is used to assess the technical condition of the old continuous rigid frame bridge in service. Obtaining the bridge technical condition assessment result specifically includes the following sub-steps:

[0130] Step S50101, obtain the undetected data of the old continuous rigid frame bridge in service, and set the uncertainty probability of the undetected data to 1, set a grade scale and a first weight for the field detection data, and obtain the component assessment result according to the uncertainty probability, the grade scale and the first weight.

[0131] In this embodiment, the undetected data refers to data that has not been tested for the parameters of the old continuous rigid frame bridge in service. Each test parameter result is scaled according to the non-destructive testing parameters detected on site, and the scale is 1-5. The scale of each non-destructive testing parameter corresponds to the probability of belonging to a certain level, that is, when the scale is a certain level, the probability of belonging to a certain level is 1, and the probabilities of other levels are all 0. For the undetected parameters, their uncertain probability can be taken as 1, and the corresponding weight is set for each test data. Set H as the probability of not belonging to any level. According to the evidence theory reasoning algorithm, the probabilities corresponding to each on-site test data are synthesized, and the evaluation process of one level is completed.

[0132] The component evaluation result satisfies the following formula:

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139] in, Indicates the rating result level is The function of Indicates the level The synthesis function of is the normalization constant, Indicates the maximum serial number of a component. Indicates the component number. Representation component Rated as level The probability function of is the probability of uncertainty in level due to incomplete information. represents the probability that the level is uncertain due to the weight of the field detection data on the component data, Indicates that the evaluation result level is an uncertain function. represents a probability function of uncertainty in level caused by the weight of the field detection data on the component data, represents the probability function of uncertainty in level due to incomplete information. Indicates the highest rating. Indicates the grade after synthesis is The probability of It indicates the probability that the grade after synthesis is uncertain.

[0140] Step S50102, setting a second weight for the component data, and obtaining a component evaluation result according to the component evaluation result and the second weight.

[0141] In this embodiment, the weight of each component to the related parts is set, and the evaluation results of all individual components are synthesized according to the above-mentioned synthesis rules to obtain the probability of each component belonging to a certain level. Undetected components are treated as uncertain information, and the weights of components within the same part are the same.

[0142] Step S50103, setting a third weight for the component data, and obtaining a structure evaluation result according to the component evaluation result and the third weight.

[0143] In this embodiment, the weight of each component to the overall structure is set, and the probability of each component belonging to a certain level is synthesized according to the above synthesis rules to obtain the probability of the overall structure belonging to a certain level. For components that are not considered or do not exist, the weight is adjusted to 0, and other weights are readjusted according to the original proportion, and the scaled probability of the overall structure is synthesized according to the evidence theory reasoning algorithm.

[0144] Step S50104, obtaining a bridge technical condition assessment result based on the structure assessment result.

[0145] In this embodiment, the assessed membership levels are corresponded to bridges of categories 1 to 5 of the bridge technical conditions, and the level with the highest probability of belonging to a certain level is taken as the category of the bridge technical condition.

[0146] It should be noted that the weights of the inspection parameters in the technical condition assessment of bridges are obtained based on the expert experience method in the "Highway Bridge Bearing Capacity Inspection and Assessment Procedure", and the weights of components and structures are obtained based on the expert experience method in the "Highway Bridge Technical Condition Assessment Standard".

[0147] Step S502, the bridge assessment data includes bridge survey data, and the structural bearing capacity of the bridge status model is assessed according to the bridge technical condition assessment result, the on-site test data and the bridge survey data to obtain a bridge structural bearing capacity assessment result.

[0148] The bridge assessment data includes bridge survey data. According to the bridge technical condition assessment result, the on-site test data and the bridge survey data, the structural bearing capacity of the bridge status model is assessed. Obtaining the bridge structural bearing capacity assessment result specifically includes the following sub-steps:

[0149] Step S50201, performing structural verification on the current status model of the bridge according to the bridge technical status assessment result, the on-site detection data and the bridge survey data.

[0150] In this embodiment, the structure of the original design model of the bridge is first verified according to the bridge survey data, and the structure of the current status model of the bridge is verified based on the structural verification results of the original design model of the bridge, the technical condition assessment results of the bridge, the on-site inspection data and the bridge survey data.

[0151] The purpose of structural verification is to ensure that the old continuous rigid frame bridge in service can safely and reliably withstand various expected loads within the design service life and meet the functional requirements of normal use. It mainly analyzes and verifies the mechanical properties of the old continuous rigid frame bridge in service, such as strength, stiffness, and stability.

[0152] Through structural verification, potential problems in the design can be discovered, and safety accidents can be avoided during the use of old continuous rigid frame bridges in service. It can also reasonably determine the bearing capacity of old continuous rigid frame bridges in service, providing a scientific basis for the maintenance, reinforcement or renovation of old continuous rigid frame bridges in service. For example, when renovating an old bridge, structural verification can help engineers determine whether the bridge needs to be reinforced and determine the appropriate reinforcement plan.

[0153] Step S50202: Based on the result of the structural verification, the structural bearing capacity of the existing bridge model is evaluated to obtain the evaluation result of the bridge structure bearing capacity.

[0154] In this embodiment, the bearing capacity of the bridge is assessed according to existing specifications, and factors such as technical condition assessment results, constant load conditions, heavy traffic impact, material degradation, etc. are considered during the assessment based on the current model of the bridge.

[0155] The bridge structure bearing capacity assessment result satisfies the following formula:

[0156]

[0157] in, is the importance coefficient of the structure, is the load effect function, is the structural self-weight adjustment coefficient, is the basic variable load adjustment factor, is the load adjustment factor for other participating load combinations, is the resistance effect function, is the measured material strength value, is the cross-sectional reduction factor of the steel bar, is the geometric parameter value of the component reinforcement, is the load-bearing capacity checking coefficient, is the load-bearing capacity deterioration factor.

[0158] In an optional embodiment, the structural bearing capacity of the bridge status model is assessed based on the bridge technical condition assessment result, the on-site detection data and the bridge survey data, and obtaining the bridge structural bearing capacity assessment result specifically includes the following sub-steps:

[0159] Step S50203, based on the load test of the old continuous rigid frame bridge in service, obtain load test data.

[0160] In this embodiment, the load test is a scientific method for directly testing the performance of the old continuous rigid frame bridge structure in service. It applies various loads on the old continuous rigid frame bridge structure in service to simulate the stress state of the bridge during actual use, so as to obtain the actual mechanical response of the old continuous rigid frame bridge structure in service, such as strain, deflection, cracks and other data.

[0161] Step S50204, based on the bridge technical condition assessment result, the on-site detection data and the bridge survey data, the structural bearing capacity of the bridge status model is assessed using the load test data to obtain the bridge structural bearing capacity assessment result.

[0162] In this embodiment, based on the load test of the old continuous rigid frame bridge in service, the load test data is included in the analysis, and the bridge structure bearing capacity can be evaluated according to the load test data. When the load test data is used to evaluate the bearing capacity, the test results such as the calibration coefficient, residual effect, crack development, and settlement displacement are first used for basic judgment. If the above four items meet the requirements, the structural bearing capacity of the bridge status model can be evaluated according to the bridge technical status evaluation results, the on-site detection data, and the bridge survey data, and the load test data is used to obtain the bridge structure bearing capacity evaluation result.

[0163] The evaluation result of the bearing capacity of the bridge structure satisfies the following formula:

[0164]

[0165] in, is the importance coefficient of the structure, is the load effect function, is the structural self-weight adjustment coefficient, is the basic variable load adjustment factor, is the load adjustment factor for other participating load combinations, is the resistance effect function, is the measured material strength value, is the cross-sectional reduction factor of the steel bar, is the geometric parameter value of the component reinforcement, is the load capacity verification coefficient after load test, is the load-bearing capacity deterioration factor.

[0166] The bearing capacity assessment generally needs to assess the bearing capacity of the current model according to the "Highway Bridge Bearing Capacity Test and Assessment Procedure", but since the influence of concrete geometric parameters and concrete section reduction has been considered in the bridge current model, the bearing capacity assessment of the present invention does not need to be repeated, and only the steel bar geometric parameters and steel bar section reduction coefficients that have not been mentioned before need to be considered. In terms of load effects, the results of the on-site test that affect the bearing capacity of the structure should be considered to correct the load effects. Due to the different standards and scales of bridge verification standards in different eras, the verification standards for bearing capacity assessment will also be different, that is, which standard is the target that the bridge structure bearing capacity verification needs to meet. There are currently three common standard specifications: "Highway Reinforced Concrete and Prestressed Concrete Bridge and Culvert Design Specification" (JTG 3362-2018), "Highway Reinforced Concrete and Prestressed Concrete Bridge and Culvert Design Specification" (JTG D62-2004), "Highway Reinforced Concrete and Prestressed Concrete Bridge and Culvert Design Specification" (JTJ 023-85). When the bridge was originally designed, different standards and specifications were selected according to its construction year. The inspection and evaluation of old bridges selects corresponding standards and specifications for verification based on the goals of subsequent maintenance, treatment and reinforcement.

[0167] Step S503: the bridge assessment data includes durability test data, and the structural durability of the old continuous rigid frame bridge in service is assessed according to the durability test data to obtain a bridge structure durability assessment result.

[0168] In this embodiment, the durability design of the bridges designed in the early stage mainly depends on the engineering experience of the designers due to the lack of relevant standards and specifications for durability design. The durability evaluation of the old continuous rigid frame bridges can be selectively carried out according to the construction period, the need for disease cause analysis and the need for durability life prediction. The durability evaluation results can be used as the basis for the durability treatment and durability design of the bridges.

[0169] The durability assessment is mainly carried out based on standards such as "Durability Assessment Standard for Existing Concrete Structures" (GB / T51355-2019) and "Technical Standard for Building Structure Testing" (GB / T50344-2019).

[0170] Step S504, obtaining the evaluation result of the current structure of the bridge according to the evaluation result of the technical condition of the bridge, the evaluation result of the bearing capacity of the bridge structure and the evaluation result of the durability of the bridge structure.

[0171] In this embodiment, a comprehensive evaluation is conducted on the old continuous rigid frame bridges in service through the bridge technical condition assessment results, the bridge structure bearing capacity assessment results and the bridge structure durability assessment results.

[0172] like Figure 2 As shown, on the other hand, the present invention also provides an evaluation system for old continuous rigid frame bridges in service, comprising: a processor, an input device, an output device and a memory, wherein the processor, the input device, the output device and the memory are interconnected, wherein the memory is used to store a computer program, and the computer program includes program instructions, and the processor is configured to call the program instructions to execute relevant steps of a relevant embodiment of a method for evaluating old continuous rigid frame bridges in service of the present invention.

[0173] In the evaluation system for old continuous rigid frame bridges in service provided by the present invention, each functional component can be integrated into one processing component, or each component can exist physically separately, or two or more components can be integrated into one component. The above-mentioned integrated components can be implemented in the form of hardware or in the form of software functions, further improving the overall applicability and practical application ability of the present invention.

[0174] The present invention can integrate existing detection means and evaluation methods, starting from the characteristics of the bridge structure itself, and on the premise of ensuring the safety of the bridges in service, deeply explore bridge diseases and their causes, comprehensively and systematically point out the current conditions of old bridges in service, and play a macro-guiding role in maintenance and repair, treatment design, maintenance decision-making, etc., avoiding the problems of incomplete detection and one-sided treatment in the past.

[0175] In general, when evaluating in-service continuous rigid frame bridges, how to obtain accurate and objective current structure has always been a difficulty and pain point faced by inspection and design personnel. The present invention takes the consistency between the original design model of the bridge and the historical cumulative measurement results as the goal, and provides a method for structural inversion analysis. The method has a simple principle and is easy to operate, making the current structure simulation more objective and reliable, and more scientific and reliable than the previous simulation of the current model based on the engineering experience of the calculator.

[0176] The invention provides a detection method for main parameters of an old continuous rigid frame bridge in service and an application method for detection parameter results, unifies the detection result and result evaluation, and avoids the embarrassing situation that there are only results but no conclusions in previous detections.

[0177] The technical condition assessment method proposed in the present invention can incorporate a large number of non-destructive testing results into the evaluation system, and can give the probability of components, parts and structures belonging to each level, and can also give the probability of uncertain levels. Compared with previous assessments, it is more comprehensive, scientific and precise.

[0178] The present invention can provide inspection engineers with recommendations on inspection content and methods based on the characteristics of actual bridges, and provide basic data for inspectors to formulate inspection plans. At the same time, it can give the development trend of bridge disease deterioration based on the evaluation results, and provide maintenance and treatment recommendations and common reinforcement and repair measures. These system features are currently lacking or not involved in the bridge inspection industry.

[0179] Although the implementation object of the present invention is an old continuous rigid frame bridge in service, the commonly used detection methods and assessment methods are universal. For beam bridges with upper structures of reinforced concrete or prestressed concrete structures, the present invention can selectively apply some or all of the methods according to their characteristics.

[0180] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for evaluating old continuous rigid frame bridges in service, characterized in that: The method comprises: Establishing data detection mechanism and data investigation mechanism related to the old continuous rigid frame bridge in service; Obtaining bridge assessment data through the data detection mechanism and the data investigation mechanism; The bridge assessment data includes original bridge design data, and an original bridge design model is constructed based on the original bridge design data; Constructing a bridge status model according to the original bridge design model and the bridge assessment data; Based on the bridge assessment data and the bridge status model, the current structure of the old continuous rigid frame bridge in service is assessed to obtain a bridge current structure assessment result; The obtaining of bridge assessment data through the data detection mechanism and the data investigation mechanism includes: Based on the investigation of the old continuous rigid frame bridge in service, bridge investigation data are obtained; Based on the detection of the structural damage of the old continuous rigid frame bridge in service, the bridge structure damage data is obtained; Based on the detection of the structural dead load condition of the old continuous rigid frame bridge in service, the bridge structure dead load data is obtained; Based on the detection of the concrete box girder material properties of the old continuous rigid frame bridge in service, the bridge concrete material property data is obtained; Based on the detection of the concrete durability parameters of the old continuous rigid frame bridge in service, bridge durability parameter data is obtained; Based on the detection of the prestressed system of the old continuous rigid frame bridge in service, the prestressed system data of the bridge is obtained; Based on the effectiveness test of the reinforcement measures of the old continuous rigid frame bridge in service, the effectiveness data of the bridge reinforcement measures are obtained; Based on the self-vibration characteristic test of the upper structure of the old continuous rigid frame bridge in service using the pulsation method, the stiffness attenuation data of the bridge structure is obtained; Based on the detection of the integrity and length of the pile foundation of the old continuous rigid frame bridge in service, the bridge hidden engineering data is obtained; The constructing of the bridge status model according to the original bridge design model and the bridge assessment data comprises: By performing sensitivity analysis on the original design model of the bridge, a sensitivity analysis result is obtained; Based on the sensitivity analysis results and the bridge assessment data, a time-varying effect analysis is performed on the original design model of the bridge to construct a current status model of the bridge; Obtaining historical cumulative measured deformation data of the old continuous rigid frame bridge in service; According to the historical accumulated measured deformation data, the evolution process of the bridge status model is analyzed until the deformation data obtained by calculating the bridge status model and the historical accumulated measured deformation data reach a threshold value; The method of evaluating the current structure of the old continuous rigid frame bridge in service based on the bridge evaluation data and the bridge current status model to obtain the evaluation result of the bridge current status structure includes: The bridge assessment data includes on-site inspection data. Based on the theory of evidence, the on-site inspection data is used to assess the technical condition of the old continuous rigid frame bridge in service to obtain the bridge technical condition assessment result; The bridge assessment data includes bridge survey data, and the structural bearing capacity of the bridge status model is assessed according to the bridge technical condition assessment result, the on-site test data and the bridge survey data to obtain a bridge structural bearing capacity assessment result; The bridge evaluation data includes durability test data, and the structural durability of the old continuous rigid frame bridge in service is evaluated according to the durability test data to obtain a bridge structure durability evaluation result; According to the bridge technical condition assessment result, the bridge structure bearing capacity assessment result and the bridge structure durability assessment result, the bridge current structure assessment result is obtained; according to the bridge technical condition assessment result, the on-site detection data and the bridge survey data, the structural bearing capacity of the bridge current model is assessed to obtain the bridge structure bearing capacity assessment result, including: Based on the load test of the old continuous rigid frame bridge in service, load test data is obtained; According to the bridge technical condition assessment result, the on-site detection data and the bridge survey data, the structural bearing capacity of the bridge status model is assessed using the load test data to obtain the bridge structural bearing capacity assessment result; The bridge structure bearing capacity assessment result satisfies the following formula: γ0S(f g ,f Q ,f e )<1.05·R(f t ,x s a ds )Z2(1-ξ e ) Among them, γ0 is the importance coefficient of the structure, S(·) is the load effect function, and f g is the structural self-weight adjustment factor, f Q is the basic variable load adjustment factor, f e is the load adjustment factor of other participating load combinations, R(·) is the resistance effect function, and f t is the measured material strength value, ξ s is the cross-sectional reduction factor of the steel bar, α ds is the geometric parameter value of the steel bar of the component, Z2 is the load capacity check coefficient after the load test, ξ e is the load-bearing capacity deterioration factor.

2. According to the method for evaluating an old continuous rigid frame bridge in service as described in claim 1, the data of the old continuous rigid frame bridge in service includes an overall structure data, the overall structure data includes one or more component data, the component data includes one or more component data, the component data includes one or more field detection data, characterized in that: Based on the evidence theory, the technical condition of the old continuous rigid frame bridge in service is evaluated by using the field test data to obtain the evaluation results of the bridge technical condition, including: Obtaining undetected data of an old continuous rigid frame bridge in service, and setting the uncertainty probability of the undetected data to 1, setting a grade scale and a first weight for the field detection data, and obtaining a component assessment result according to the uncertainty probability, the grade scale and the first weight; Setting a second weight for the component data, and obtaining a component evaluation result according to the component evaluation result and the second weight; Setting a third weight for the component data, and obtaining a structure assessment result according to the component assessment result and the third weight; Based on the structural assessment results, the technical condition assessment results of the bridge are obtained.

3. The method for evaluating an old continuous rigid frame bridge in service according to claim 2, characterized in that: The component assessment results satisfy the following formula: Among them, H n Represents a function of the evaluation result level n, m n represents the synthesis function of level n, k is the normalization constant, L represents the maximum number of components, i represents the component number, m n，i Indicates that component i is rated as grade H n The probability function of is the probability of uncertainty in level due to incomplete information. represents the probability that the grade is uncertain due to the weight of the on-site detection data on the component data, H represents the function that the grade of the evaluation result is uncertain, represents a probability function of uncertainty in level caused by the weight of the field detection data on the component data, represents the probability function of uncertainty in the grade due to incomplete information, N represents the highest grade, β n Indicates that the grade after synthesis is H n The probability of H It indicates the probability that the grade after synthesis is uncertain.

4. The method for evaluating an old continuous rigid frame bridge in service according to claim 1, characterized in that: The step of evaluating the structural bearing capacity of the bridge status model according to the bridge technical status evaluation result, the on-site detection data and the bridge investigation data to obtain the bridge structural bearing capacity evaluation result includes: Performing structural verification on the current status model of the bridge according to the bridge technical status assessment result, the on-site test data and the bridge survey data; Based on the result of the structural verification, the structural bearing capacity of the existing bridge model is evaluated to obtain the evaluation result of the bridge structure bearing capacity.

5. An evaluation system for old continuous rigid frame bridges in service, characterized in that: include: A processor, an input device, an output device and a memory, wherein the processor, the input device, the output device and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions to execute a method for evaluating an old continuous rigid frame bridge in service as described in any one of claims 1 to 4.

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