An intelligent pre-pressing method and system for hanging basket pre-pressing test in bridge construction

Abstract

The application discloses an intelligent pre-pressing method and system for hanging basket pre-pressing test in bridge construction, and relates to the technical field of bridge engineering construction.The method comprises the following steps: a grading load adding and unloading scheme is formulated, and loads are applied step by step.In each load holding stable stage, the comprehensive stiffness index of the hanging basket is calculated based on the load and displacement increment of the pull rope sensor; the measured extreme values of strain, displacement and crack width are extracted, and the comprehensive structure response index is calculated.A loading rate adjustment factor is calculated according to the current response index, and the target hydraulic loading rate of the next stage is determined in combination with the response index change rate and the load level of the adjacent stage.The spatial displacement of the key plane of the structure is reconstructed according to the measured displacement of the visual measuring point, and the theoretical displacement of the finite element is compared point by point, and the continuous grid area exceeding the allowable deviation is automatically marked as displacement anomaly and early warning is given.After the overload verification stage load holding and all unloading are completed, the monitoring response extreme value and residual displacement are read, the pre-pressing qualified comprehensive score is calculated, and whether the pre-pressing is qualified is determined by comparing with the threshold value.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering construction technology, and in particular relates to an intelligent preloading method and system for preloading tests using hanging baskets in bridge construction. Background Technology

[0002] The hanging basket is the core mobile formwork device in cantilever bridge construction, bearing the concrete formwork and construction loads and advancing segment by segment as the pouring progresses. According to relevant specifications, the hanging basket must undergo a pre-stressing test before the formal pouring operation to verify the load-bearing capacity and stiffness of the hanging basket structure and obtain the elastic deformation at key measuring points, which serves as the basis for setting the pre-camber of subsequent beam segments.

[0003] The existing pre-compression method for hanging baskets has the following five shortcomings: First, there is a lack of an adaptive control mechanism for the loading rate. Load application mainly relies on operators manually adjusting the hydraulic system based on their experience. The loading rate is decoupled from the real-time response state of the hanging basket structure, and it is impossible to dynamically adjust the rate according to the stress and deformation degree of the structure at the current loading level. This poses a safety risk of local structural overload due to excessively rapid loading.

[0004] Second, data from multiple sensors are processed in isolation, lacking comprehensive evaluation indicators. Monitoring data from strain gauges, displacement sensors, and visual measurement points are analyzed independently, without establishing a unified quantitative evaluation index that can comprehensively reflect the overall stress and deformation state of the hanging basket. This makes it difficult to achieve a global, real-time assessment of the safety margin of the hanging basket structure.

[0005] Third, the structural spatial displacement field cannot be quantitatively reconstructed. Existing methods can only obtain displacement data from a limited number of discrete measurement points, lacking quantitative characterization of the deformation state of the structural region between measurement points. The identification of abnormal deformation regions relies entirely on manual visual judgment, which is inaccurate and carries the risk of missed detections.

[0006] Fourth, there is a lack of comprehensive quantitative standards for determining whether pre-stressing is qualified. Qualification is based on whether various monitoring responses meet their respective limits, resulting in fragmented and highly subjective standards. A unified scoring mechanism for the overall structural health of the hanging basket has not been established.

[0007] Fifth, there is a systematic bias in the calibration values ​​of elastic deformation. Existing methods do not consider the nonlinear difference in elastic deformation between overload conditions (120% design load) and formal pouring conditions (100% design load) when calculating calibration values, resulting in higher calibration values ​​and affecting the accuracy of pre-camber setting. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention proposes an intelligent preloading method for hanging basket preloading tests in bridge construction, comprising: A graded loading and unloading scheme for overload verification was formulated and the load was applied step by step. The comprehensive stiffness index of the hanging basket was calculated based on the load and displacement increment data of each rope displacement sensor during the load holding and stabilization stage of each loading level. During the stable bearing stage of each loading level, the measured extreme values ​​of strain, displacement, and crack width are extracted, and the comprehensive structural response index is calculated. At the end of each loading stage, the loading rate adjustment factor is calculated based on the comprehensive structural response index of the current loading stage, and the target hydraulic loading rate of the next loading stage is calculated by combining the rate of change of the comprehensive structural response index of the adjacent loading stages with the current load level. Based on the actual displacement data measured by visual measurement points, the spatial displacement of the key plane of the hanging basket structure is reconstructed. The reconstructed spatial displacement is compared point by point with the displacement calculated by finite element theory at the same loading level. Continuous grid point areas that exceed the allowable deviation threshold are automatically marked as abnormal displacement areas and an early warning is triggered. After completing the specified load duration and all unloading procedures for the overload verification level, the extreme values ​​of various monitoring responses and the residual displacement after complete unloading are read. The preload qualification comprehensive judgment score is calculated and combined with the set qualification threshold to determine whether the preload is qualified.

[0009] Furthermore, before developing the graded loading and unloading scheme for overload verification, it is also necessary to deploy a multi-sensor monitoring network on the hanging basket structure, which includes strain monitoring units, rope displacement sensor units, and visual displacement measurement point units, and synchronously collect the reference state data of all sensors under zero load conditions.

[0010] Furthermore, it also includes: after the preloading is deemed qualified, based on the average displacement data of the effective loading and unloading cycles, the nonlinear elastic deformation difference between the overload condition and the formal pouring condition is corrected by the overload correction factor, the calibration value of the elastic deformation of each measuring point is calculated, the calibration value is used as the quantitative basis for the precamber setting of each beam segment in the subsequent construction, and all preloading monitoring data are summarized to form a preloading test report.

[0011] Furthermore, the calculation of the overall stiffness index of the hanging basket includes:

[0012] in, For the first The overall stiffness index of the undercarriage basket at each loading stage. This represents the total number of single-sided pull-wire displacement sensors. For the first The reliability weight of a single draw-wire displacement sensor For the first Under the first load level and the first The actual applied load of the jacks arranged at the same location as the rope displacement sensors. For the first Under the first load level and the first The measured displacement of a single pull-string displacement sensor In order to be with the first The reference displacement collected by a single draw-wire displacement sensor under zero load conditions. This is the stiffness temperature correction factor. For the first The difference between the field temperature and the reference temperature under each loading level Reference temperature; When the ratio of the comprehensive stiffness index of the hanging basket of adjacent loading levels At that time, loading was paused and a comprehensive inspection of the hanging basket structure was conducted, including... For the first The overall stiffness index of the undercarriage basket under each loading stage.

[0013] Furthermore, the calculation of the comprehensive structural response index includes:

[0014] in, For the first The comprehensive structural response index under each loading level For the first The fusion weight of monitoring data For the first Under the first load level Measured extreme values ​​of monitoring data For the first The design allowable values ​​for class monitoring data, For the first The penalty index for monitoring data, The normalized index; when Immediately pause loading and send an alarm to the site.

[0015] Furthermore, the calculation of the loading rate adjustment factor includes:

[0016] in, For the first Load rate adjustment factor under each load level This is the lower limit of the loading rate adjustment factor. The upper limit of the loading rate adjustment factor; The calculation of the target hydraulic loading rate includes:

[0017] in, For the first Target hydraulic loading rate at each loading level This is the reference composite structural response index corresponding to the optimal loading rate. Adjust the sensitivity bandwidth to adjust the loading rate. As the reference hydraulic loading rate, The structural response acceleration penalty coefficient, For the first Load increments at each loading level For the formal pouring of the design load, For the first Load level attenuation factor under each loading level For the first The cumulative applied load under each loading level; Will After being processed by upper and lower limit amplitude control, the signal is input into the hydraulic control system.

[0018] Furthermore, the spatial displacement of the key plane of the reconstructed hanging basket structure includes:

[0019]

[0020] in, For reconstruction point Spatial displacement at that location, This represents the number of visual measurement points on one side. For the first Each visual measurement point is used to reconstruct the point. interpolation weights, For the first Measured displacement of each visual measurement point To introduce the number of structural correction modes, For the first Amplitude coefficients of the modified mode of the first structure. For the first The structural modal shape function of the modified structural mode at point The value at that location, For reconstruction point To the Euclidean distance between visual measurement points The distance decay exponent, For the first Local stiffness weighted correction factor at each visual measurement point For the first Local stiffness weighted correction factor at each visual measurement point For reconstruction point To the Euclidean distance between visual measurement points; when The absolute value of the difference between the displacement calculated by finite element theory and the displacement exceeds the allowable deviation threshold of the theoretical value and continuously covers... When there are one or more grid points, the corresponding continuous grid point area will be marked as a displacement anomaly area and an early warning and loading will be paused.

[0021] Furthermore, the calculation of the comprehensive judgment score for preloading qualification includes:

[0022] in, The comprehensive score for pre-compression qualification is as follows: For the first The penalty weight of monitoring data in the qualification determination, For the final load level Next The measured extreme values ​​of the monitoring data of the first class, The design allowable values ​​for class monitoring data, The residual-elastic deformation ratio penalty coefficient. This represents the maximum absolute value of the residual displacement at each measuring point after complete unloading. This is the theoretical elastic deformation. when When the preload is deemed qualified, The system will determine if the preload is unqualified and output a detailed report of the over-limit.

[0023] Furthermore, the calibration values ​​for the elastic deformation at each measuring point are calculated, including:

[0024] in, For the first The calibration value of elastic deformation at each measuring point. To effectively increase the number of loading and unloading loops, For the first The second effective load / unload cycle occurs at the final load level. Next Measured displacement at each measuring point For the first Before the first effective load / unload loop loading... Initial displacement of each measuring point For the first Overload correction factor for each measuring point To apply the actual load to the final loading stage, The design load is for formal pouring.

[0025] This invention also proposes an intelligent preloading system for preloading tests using hanging baskets in bridge construction, comprising: The stiffness index calculation module is used to formulate a graded loading and unloading scheme for the overload verification level and apply the load step by step. In the holding and stabilization stage of each loading level, the comprehensive stiffness index of the hanging basket is calculated based on the load and displacement increment data of each rope displacement sensor. The structural response index calculation module is used to extract the measured extreme values ​​of strain, displacement, and crack width at each loading stage and during the load stabilization phase, and to calculate the comprehensive structural response index. The hydraulic control module is used to calculate the loading rate adjustment factor based on the comprehensive structural response index of the current loading level at the end of each loading level, and to calculate the target hydraulic loading rate of the next loading level by combining the rate of change of the comprehensive structural response index of the adjacent loading levels with the current load level. The displacement anomaly judgment module is used to reconstruct the spatial displacement of the key plane of the hanging basket structure based on the actual displacement data measured by visual measurement points. The reconstructed spatial displacement is compared with the displacement calculated by finite element theory at the same loading level point by point. Continuous grid point areas that exceed the allowable deviation threshold are automatically marked as displacement anomaly areas and an early warning is triggered. The preload qualification judgment module is used to read the extreme values ​​of various monitoring responses of the overload verification level and the residual displacement after complete unloading after the specified holding time and all unloading procedures of the overload verification level, calculate the comprehensive judgment score of preload qualification, and judge whether the preload is qualified in combination with the set qualification threshold.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects: (1) A unified fusion and evaluation of multi-source heterogeneous monitoring data was achieved. (Comprehensive Structural Response Index) By incorporating monitoring data of three different physical properties—strain, displacement, and crack width—into the same quantitative framework, and using a differentiated penalty index (…),… This method achieves nonlinear weighting of different types of responses, comprehensively and objectively reflecting the real-time stress and deformation state of the hanging basket structure, overcoming the shortcomings of existing methods where various types of data are independent and difficult to evaluate as a whole.

[0027] (2) Closed-loop adaptive control of hydraulic loading rate based on structural response feedback was achieved. Loading rate adjustment factor. With the overall structural response index The dynamic change occurs with the rate of change being highest when the structural response is near 50% of the allowable value, and automatically and significantly decreasing as it approaches the limit; this is combined with a response acceleration penalty term ( ) and load level attenuation term ( This forms a triple adaptive control mechanism, effectively preventing local structural overruns caused by excessively rapid loading.

[0028] (3) Quantitative and continuous reconstruction of the spatial displacement field of the key structural plane of the hanging basket and automatic anomaly localization were realized. The limited data of 12 visual discrete measurement points were expanded into a continuous displacement field of the key plane of the hanging basket, and a structural stiffness weighted correction factor was introduced. The addition of structural modal correction terms ensures that the reconstruction results fully incorporate the mechanical constraints of the hanging basket structure, resulting in a reconstruction accuracy higher than that of the pure distance-weighted interpolation method. Displacement anomaly areas are automatically marked by the system, with objective criteria (deviations of 3 or more consecutive grid points exceeding the theoretical value by 15%), eliminating the subjectivity of manual visual judgment and the risk of missed detection.

[0029] (4) A comprehensive quantitative judgment mechanism for pre-compression qualification has been established, with unified and objective criteria. Qualification score Simultaneously consider the degree of exceeding limits in various monitoring responses (through... (Weighted) and the ratio of residual deformation to elastic deformation (through) (Punishment), using a unified 100-point scoring system to provide an objective quantitative evaluation of the overall structural condition of the hanging basket, The qualified threshold avoids the disputes caused by subjective trade-offs arising from multiple parallel criteria in existing methods.

[0030] (5) Improved the accuracy of elastic deformation calibration values ​​and reduced the systematic deviation in pre-camber setting. Overload correction factor For overload conditions ( ) and formal pouring conditions ( The nonlinear difference in elastic deformation between the two is corrected to make the calibration value more accurately represent the actual elastic deformation under the formal pouring conditions. Numerical examples show that the calibration value deviation can be reduced by about 2.5% after introducing overload correction, which has significant implications for the accuracy control of the pre-camber of long-span continuous rigid frame bridges. Attached Figure Description

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart of the method in Embodiment 1 of the present invention; Figure 2 This is a system structure diagram of Embodiment 2 of the present invention; Figure 3 This is a system structure diagram of Embodiment 4 of the present invention; Figure 4 This is a first schematic diagram of the sensor arrangement of the present invention; Figure 5 This is a second schematic diagram of the sensor arrangement of the present invention. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0034] Example 1 like Figure 1 As shown in the figure, this embodiment proposes an intelligent preloading method for hanging basket preloading tests in bridge construction, including: Preferably, during the construction stage of block 0 ("block 0" refers to the first concrete beam segment directly cast on the top of the pier), the pre-embedded parts of the reaction frame are completed on the web of the end face of block 0 according to the design drawings. The number of pre-embedded parts on one side is 6, and the arrangement position is strictly in accordance with the coordinates determined in the drawings. After the concrete strength of block 0 reaches the design value, the hanging basket is installed and positioned, the reaction frame is assembled as a whole (six pieces in total), and the jacks and hydraulic control system are installed and debugged.

[0035] Collect and record the following structural parameters of the hanging basket: elastic modulus of each main truss member section. (GPa), Calculation length (mm), moment of inertia of cross section ( Based on the load calculated by the hanging basket design, determine the total design load for formal pouring. (kN).

[0036] The preload loading scheme adopts a staged loading and unloading procedure, with each loading stage based on the applied load. With formal pouring design load ratio The load levels are set sequentially as follows: 0, 0.30, 0.50, 1.00, 1.20 (overload verification level), 1.00, 0.50, 0 (unloading complete), for a total of 8 load levels, corresponding to the level sequence numbers. ; Duration of holding load at each level Not less than 30 minutes, overload level ( , The load duration shall not be less than 120 minutes; all types of monitoring data shall be read within 5 minutes of the remaining load stabilization time at each level.

[0037] like Figure 4 and Figure 5 As shown, after determining the structural parameters of the hanging basket and completing the installation and commissioning, the three types of monitoring equipment will be fully deployed according to the following plan.

[0038] (1) Strain monitoring deployment: Strain gauges are attached to the middle of the critical stress sections of each component of the hanging basket, and the total number of strain measurement points on one side is [not specified]. ( The approach bridge side measuring points are symmetrically arranged with the main bridge side measuring points. The main bridge side measuring points are numbered with "main" as a prefix, and the approach bridge side measuring points are numbered with "approach" as a prefix. Figure 5 (Not shown), each is followed by a sequential number starting from 1; before pasting the strain gauge, the pasting surface must be ground with a grinding wheel and wiped clean with an alcohol swab. After pasting, use a multimeter to check the insulation resistance value, which should not be less than 100 MΩ. Solder the strain gauge lead and the wire to the terminal block respectively.

[0039] (2) Deployment of rope displacement sensors: rope displacement sensors are deployed on one side. indivual( ), numbered ; among which the number The pull-rope displacement sensor is placed inside the front fulcrum box, numbered... The rope displacement sensor is placed inside the rear anchor point box; based on the sensor signal quality (out of 1.0), it is rated as the first... Each pull-wire displacement sensor is assigned a reliability weighting factor. (Dimensionless), initial values ​​are all set to If a cable displacement sensor experiences signal drift or a broken wire, then it will be... The correction value is reduced to no less than 0.1 to reduce its impact on the calculation of the composite stiffness index.

[0040] (3) Deployment of visual displacement measurement points: unilateral visual measurement points indivual( ), measure the spatial displacement of the upper front crossbeam and the lower front crossbeam; install a high-precision displacement detection camera and a supplementary light at the corresponding position, and attach the visual target to the node of the hanging basket component and adjust it to the center of the camera's field of view.

[0041] After the deployment of the above three types of equipment is completed and the joint debugging test is passed, the initial readings of all sensors are collected synchronously under zero load. The initial readings of the pull-wire displacement sensors are denoted as follows: (mm), the first The reference strain at each strain measurement point is denoted as... (με), will the first The visual measurement point at the first The initial displacement before the next loading / unloading cycle is denoted as . (mm, (This corresponds to the initial state before the formal start of this pre-stressing test); the above data together constitute the structural reference state.

[0042] Step S1: Develop a graded loading and unloading scheme for the overload verification level and apply the load step by step. Calculate the comprehensive stiffness index of the hanging basket based on the load and displacement increment data of each rope displacement sensor during the load holding and stabilization stage of each loading level. Specifically, before formulating the graded loading and unloading scheme for overload verification, it is also necessary to deploy a multi-sensor monitoring network on the hanging basket structure, which includes strain monitoring units, rope displacement sensor units, and visual displacement measurement point units, and synchronously collect the reference state data of all sensors under zero load conditions.

[0043] Specifically, after completing the baseline state acquisition, the hydraulic loading system is activated, and the load is applied level by level according to the determined staged loading and unloading scheme. At each loading level... Within the remaining 5 minutes of the load stabilization time, all rope displacement sensor data are read synchronously, and the overall stiffness index of the hanging basket is calculated, including:

[0044] in, For the first The comprehensive stiffness index (kN / mm) of the lower hanging basket at each loading level reflects the equivalent overall stiffness of the current loading level lower hanging basket structure. This represents the total number of single-sided pull-wire displacement sensors. For the first Reliability weight of each draw-wire displacement sensor (dimensionless, range of values) Normal state take ), For the first Under the first load level and the first The actual applied load of the jacks arranged at the same location as the rope displacement sensors. For the first Under the first load level and the first The measured displacement of a single pull-string displacement sensor In order to be with the first The reference displacement collected by a single draw-wire displacement sensor under zero load conditions. Stiffness temperature correction factor (dimensionless, take...) This is used to eliminate the influence of environmental temperature changes on structural stiffness measurements. For the first The difference between the field temperature and the reference temperature under each loading level Reference temperature; When the ratio of the comprehensive stiffness index of the hanging basket of adjacent loading levels If the stiffness of the hanging basket structure is significantly degraded, loading should be stopped immediately. The on-site engineer should check the connection status of each component node of the hanging basket and the bolt tightness of the reaction frame and the main body of the bridge one by one. Only after the cause is confirmed and the rectification is completed can the subsequent loading steps be continued.

[0045] Step S2: In each loading stage, the measured extreme values ​​of strain, displacement, and crack width are extracted, and the comprehensive structural response index is calculated. Specifically, the calculation of the comprehensive structural response index includes:

[0046] in, For the first The comprehensive structural response index under each loading level For the first The fusion weights of the monitoring data (dimensionless, taking...) ,satisfy ), For the first Under the first load level Measured extreme values ​​of monitoring data ( The unit is με. The unit is mm. (Time unit is mm) For the first The design allowable values ​​for class monitoring data, For the first The penalty index for monitoring data (dimensionless, taking...) This is used to differentiate and amplify the degree to which different types of responses approach the allowed value. Corresponding strain monitoring, Corresponding displacement monitoring, Corresponding crack width monitoring, The normalization exponent (dimensionless, ), used to normalize the combined penalty value of various responses; when When the hanging basket structure response is in the safe region, continue executing step S3's rate control and the next stage of loading; when When the response enters the warning zone, step S3 will automatically reduce the loading rate; when If at least one type of monitoring response (measured extreme value) has reached or exceeded the design allowable value, the system will immediately suspend loading and issue an alarm to the site. The engineer will then investigate the cause before deciding whether to continue loading.

[0047] Step S3: At the end of each loading stage, calculate the loading rate adjustment factor based on the comprehensive structural response index of the current loading stage, and calculate the target hydraulic loading rate of the next loading stage by combining the rate of change of the comprehensive structural response index of the adjacent loading stages with the current load level. Preferably, the comprehensive structural response index is obtained in real time in step S2. Based on this, at the end of each loading stage, the hydraulic control system adaptively calculates the target rate for the next loading stage in the following two steps: Step 31, calculating the loading rate adjustment factor includes:

[0048] in, For the first The loading rate adjustment factor (dimensionless) at each loading level reflects the degree of deviation of the current structural response state from the optimal loading rate. The lower limit of the loading rate adjustment factor (dimensionless, taking...) This corresponds to the minimum allowable loading rate ratio when the structural response is extremely low or extremely high. The upper limit of the loading rate adjustment factor (dimensionless, take...) This corresponds to the maximum allowable loading rate ratio when the structural response is in the optimal range. Step S32, calculating the target hydraulic loading rate includes:

[0049] in, For the first Target hydraulic loading rate at each loading level The reference composite structural response index (dimensionless, taken as) corresponding to the optimal loading rate This indicates that the loading rate adjustment factor reaches its maximum value when the structural response is near 50% of the allowable value. Adjust the sensitivity bandwidth (dimensionless, take) for the loading rate. ), controls the width of the Gaussian function, determines Follow Changes in response sensitivity As the reference hydraulic loading rate, The structural response acceleration penalty coefficient (dimensionless, taken as...) When the rate of increase of the structural response exceeds the rate of increase of the load (i.e., the structure exhibits a nonlinear softening trend), an additional penalty is imposed on the loading rate. For the first Load increments at each loading level For the formal pouring of the design load, For the first Load level attenuation factor (dimensionless, taken as) under each loading level This reflects the safety principle that the loading rate should be reduced accordingly when the load level is higher and the structural margin is smaller. For the first The cumulative applied load under each loading level; Will After being processed by upper and lower limit amplitude control, the signal is input into the hydraulic control system.

[0050] in the formula The meaning of the term is as follows: if the ratio of the increment of the structural response to the increment of the load exceeds 1 (i.e., the growth rate of the structural response exceeds the growth rate of the load, resulting in nonlinear softening), then an additional penalty is applied to the loading rate; if the growth rates of the two are equal or the growth rate of the structural response is lower than the growth rate of the load (linear or hardening behavior), then the penalty term is zero, and the rate is not reduced additionally.

[0051] The output of step S3 The data is sent to the hydraulic control cabinet in real time, and each jack is controlled to load at a consistent rate. During the loading process, step S4 simultaneously performs spatial displacement reconstruction and abnormal positioning.

[0052] Step S4: Based on the measured displacement data from visual measurement points, reconstruct the spatial displacement of the key plane of the hanging basket structure. Compare the reconstructed spatial displacement with the displacement calculated by finite element theory at the same loading level point by point. Automatically mark the continuous grid point area that exceeds the allowable deviation threshold as the displacement abnormal area and trigger an early warning. Specifically, during the loading process from steps S1 to S3, based on the deployment... Based on the measured displacement data from several visual measurement points, the following spatial displacement field reconstruction model is used to continuously reconstruct the spatial displacement field of the key plane of the main truss frame of the hanging basket.

[0053] For any spatial point within the critical plane of the hanging basket structure The spatial displacement of the key plane of the reconstructed hanging basket structure includes:

[0054]

[0055] in, For reconstruction point Spatial displacement at that location, This represents the number of visual measurement points on one side. For the first Each visual measurement point is used to reconstruct the point. interpolation weights, For the first Measured displacement of each visual measurement point The number of structural correction modes introduced (dimensionless, taken as...) (This corresponds to the three main modes of bending, shear and torsion of the hanging basket). For the first The amplitude coefficients of the third-order modal correction are determined by least-squares fitting of the measured displacements at all discrete measurement points (for example, the typical result of decomposing the interpolation residuals of all 12 visual measurement points by least-squares fitting is as follows:) mm (first-order bending), mm (second-order bending), mm (torsion); the absolute values ​​of all three are much smaller than the measured displacement (approximately 5–8 mm), and after introducing corrections, the root mean square error decreased from approximately 0.25 mm to approximately 0.08 mm. For the first The structural modal shape function of the modified structural mode at point The value at that point (dimensionless) is calculated by the finite element model of the hanging basket under the initial elastic state. For reconstruction point To the Euclidean distance between visual measurement points The distance decay exponent (dimensionless, take...) ), controlling the degree of influence of distance on interpolation weights, For the first Local stiffness weighted correction factor at each visual measurement point (dimensionless, typical range of values) ), For the first Local stiffness weighted correction factor at each visual measurement point For reconstruction point To the Euclidean distance between visual measurement points; when The absolute value of the difference between the displacement calculated by finite element theory and the displacement exceeds the allowable deviation threshold of the theoretical value and continuously covers... When there are one or more grid points, the corresponding continuous grid point area will be marked as a displacement anomaly area and an early warning and loading will be paused.

[0056] Preferably, based on the reconstructed spatial displacement field, the reconstructed displacement of each grid point is... Displacement calculations at the same level as those using finite element theory Perform point-by-point comparison; when three or more consecutive grid points in a certain area meet the requirements... When the area is marked as an abnormal displacement area, the system will automatically trigger an early warning and suspend loading. The on-site engineer will then inspect the structural components in the marked area one by one. Loading can only be resumed and the rate control in step S3 can continue after the cause has been confirmed and the issue has been resolved. Step S5: After completing the specified holding time and all unloading procedures of the overload verification level, read the extreme values ​​of various monitoring responses of the overload verification level and the residual displacement after complete unloading, calculate the comprehensive judgment score for preload qualification, and determine whether the preload is qualified in combination with the set qualification threshold.

[0057] Preferably, the overload level is completed in step S3. Horizontal load The load is maintained for at least 120 minutes, and the unloading is carried out in accordance with the unloading plan. Gradually unload to zero load. After that, perform the following qualification determination procedure.

[0058] Read the final load level respectively Extreme values ​​of three types of monitoring responses ( ), and zero-load state ( The residual displacement is determined by taking the maximum absolute value of the difference between the readings at each measuring point and the baseline value of the structural reference state from all the readings of the tension rope displacement sensors. (mm); Based on the finite element model of the hanging basket, the design load The theoretical maximum elastic deformation of key measuring points is calculated below. (mm).

[0059] Specifically, the calculation of the comprehensive judgment score for preloading qualification includes:

[0060] in, The score for pre-compression qualification is dimensionless, with a maximum score of 100 points. For the first The penalty weight of monitoring data in the qualification determination (dimensionless, taking...) ,and This reflects the relative importance of various monitoring exceedances on the overall safety of the hanging basket. For the final load level Next The measured extreme values ​​of the monitoring data of the first class, The design allowable values ​​for class monitoring data, The residual-elastic deformation ratio penalty coefficient (dimensionless, taken as...) This reflects the weighting of the ratio of residual deformation to elastic deformation in the acceptance criteria. This represents the maximum absolute value of the residual displacement at each measuring point after complete unloading. This is the theoretical elastic deformation. when When the preload is deemed qualified, If the pre-stressing is deemed unqualified, an over-limit details report will be output. On-site technicians will then carry out targeted rectification and reinforcement of the hanging basket structure. After the rectification is completed, steps S1 to S5 will be executed again.

[0061] Specifically, this also includes: after the preloading is deemed qualified, based on the average displacement data of the effective loading and unloading cycles, the nonlinear elastic deformation difference between the overload condition and the formal pouring condition is corrected by the overload correction factor, the calibration value of the elastic deformation of each measuring point is calculated, the calibration value is used as the quantitative basis for setting the precamber of each beam segment in the subsequent construction, and all the preloading monitoring data are summarized to form a preloading test report.

[0062] Specifically, the calibration values ​​for calculating the elastic deformation at each measuring point include:

[0063] in, For the first The calibration values ​​of elastic deformation at each measuring point are used to guide the setting of pre-camber in the subsequent construction of each beam segment. To effectively increase the number of loading and unloading loops, For the first The second effective load / unload cycle occurs at the final load level. Next Measured displacement at each measuring point For the first Before the first effective load / unload loop loading... Initial displacement of each measuring point For the first Overload correction factor for each measuring point (dimensionless, typical value) Determined by finite element nonlinear analysis of the hanging basket, reflecting the overload condition ( ) and formal pouring conditions ( The nonlinear difference ratio of elastic deformation between ) To apply the actual load to the final loading stage, The design load is for formal pouring.

[0064] Calibration values ​​of each measuring point ( , The data is compiled and organized to form a hanging basket elastic deformation calibration report, which serves as the quantitative basis for setting the precamber in subsequent beam segment pouring. Simultaneously, the control system outputs all monitoring data from this preloading process as a preloading test report, including: load values ​​for each loading stage. Sensor readings and overall stiffness index Comprehensive structural response index Adaptive loading rate Spatial displacement field reconstruction results and qualification score and the elastic deformation calibration values ​​at each measuring point The above report, along with the original on-site monitoring data, will be archived to complete all the work for this intelligent pre-compression process.

[0065] Example 2 like Figure 2 As shown, this embodiment proposes an intelligent preloading system for hanging basket preloading tests in bridge construction, comprising: The stiffness index calculation module is used to formulate a graded loading and unloading scheme for the overload verification level and apply the load step by step. In the holding and stabilization stage of each loading level, the comprehensive stiffness index of the hanging basket is calculated based on the load and displacement increment data of each rope displacement sensor. The structural response index calculation module is used to extract the measured extreme values ​​of strain, displacement, and crack width at each loading stage and during the load stabilization phase, and to calculate the comprehensive structural response index. The hydraulic control module is used to calculate the loading rate adjustment factor based on the comprehensive structural response index of the current loading level at the end of each loading level, and to calculate the target hydraulic loading rate of the next loading level by combining the rate of change of the comprehensive structural response index of the adjacent loading levels with the current load level. The displacement anomaly judgment module is used to reconstruct the spatial displacement of the key plane of the hanging basket structure based on the actual displacement data measured by visual measurement points. The reconstructed spatial displacement is compared with the displacement calculated by finite element theory at the same loading level point by point. Continuous grid point areas that exceed the allowable deviation threshold are automatically marked as displacement anomaly areas and an early warning is triggered. The preload qualification judgment module is used to read the extreme values ​​of various monitoring responses of the overload verification level and the residual displacement after complete unloading after the specified holding time and all unloading procedures of the overload verification level, calculate the comprehensive judgment score of preload qualification, and judge whether the preload is qualified in combination with the set qualification threshold.

[0066] Since Example 2 is based on Example 1, it will not be described again.

[0067] Example 3 This invention also proposes a storage medium storing multiple instructions for implementing the intelligent preloading method for hanging basket preloading tests in bridge construction.

[0068] Optionally, in this embodiment, the storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals.

[0069] Optionally, in this embodiment, the storage medium is configured to store program code for performing the method steps of Embodiment 1.

[0070] Example 4 This invention also proposes an electronic device, such as... Figure 3 As shown, it includes a processor and a storage medium connected to the processor. The storage medium stores multiple instructions that can be loaded and executed by the processor to enable the processor to perform the intelligent preloading method for hanging basket preloading test in bridge construction.

[0071] Specifically, the electronic device in this embodiment can be a computer terminal, which may include one or more processors and a storage medium.

[0072] The storage medium can be used to store software programs and modules, such as the intelligent preloading method for hanging basket preloading tests in bridge construction according to an embodiment of the present invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the storage medium, thereby realizing the aforementioned intelligent preloading method for hanging basket preloading tests in bridge construction. The storage medium may include high-speed random access storage media, and may also include non-volatile storage media, such as one or more magnetic storage systems, flash memory, or other non-volatile solid-state storage media. In some instances, the storage medium may further include storage media remotely configured relative to the processor, which can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0073] The processor can execute the method steps of Embodiment 1 by calling the information and application stored in the storage medium through the transmission system.

[0074] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0075] In the several embodiments provided by this invention, it should be understood that the disclosed technical content can be implemented in other ways. The system embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, indirect coupling or communication connection between units or modules, and may be electrical or other forms.

[0076] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0077] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0078] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, optical disks, and other media capable of storing program code.

[0079] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An intelligent preloading method for preloading tests using hanging baskets in bridge construction, characterized in that, include: A graded loading and unloading scheme for overload verification was formulated and the load was applied step by step. The comprehensive stiffness index of the hanging basket was calculated based on the load and displacement increment data of each rope displacement sensor during the load holding and stabilization stage of each loading level. During the stable bearing stage of each loading level, the measured extreme values ​​of strain, displacement, and crack width are extracted, and the comprehensive structural response index is calculated. At the end of each loading stage, the loading rate adjustment factor is calculated based on the comprehensive structural response index of the current loading stage, and the target hydraulic loading rate of the next loading stage is calculated by combining the rate of change of the comprehensive structural response index of the adjacent loading stages with the current load level. Based on the actual displacement data measured by visual measurement points, the spatial displacement of the key plane of the hanging basket structure is reconstructed. The reconstructed spatial displacement is compared point by point with the displacement calculated by finite element theory at the same loading level. Continuous grid point areas that exceed the allowable deviation threshold are automatically marked as abnormal displacement areas and an early warning is triggered. After completing the specified load duration and all unloading procedures for the overload verification level, the extreme values ​​of various monitoring responses and the residual displacement after complete unloading are read. The preload qualification comprehensive judgment score is calculated and combined with the set qualification threshold to determine whether the preload is qualified.

2. The intelligent preloading method for preloading tests using hanging baskets in bridge construction as described in claim 1, characterized in that, Before developing the graded loading and unloading scheme for overload verification, it is also necessary to deploy a multi-sensor monitoring network on the hanging basket structure, which includes strain monitoring units, rope displacement sensor units and visual displacement measurement point units, and synchronously collect the reference state data of all sensors under zero load.

3. The intelligent preloading method for hanging basket preloading test in bridge construction as described in claim 1, characterized in that, Also includes: After the preloading is deemed qualified, the average displacement data of the effective loading and unloading cycles is used as the basis. The difference in nonlinear elastic deformation between the overload condition and the formal pouring condition is corrected by the overload correction factor. The calibration value of the elastic deformation at each measuring point is calculated. The calibration value is used as the quantitative basis for setting the precamber of each beam segment in the subsequent construction. All preloading monitoring data are summarized to form a preloading test report.

4. The intelligent preloading method for hanging basket preloading test in bridge construction as described in claim 1, characterized in that, The calculation of the overall stiffness index of the hanging basket includes: in, For the first The overall stiffness index of the undercarriage basket at each loading stage. This represents the total number of single-sided pull-wire displacement sensors. For the first The reliability weight of a single draw-wire displacement sensor For the first Under the first load level and the first The actual applied load of the jacks arranged at the same location as the rope displacement sensors. For the first Under the first load level and the first The measured displacement of a single pull-string displacement sensor In order to be with the first The reference displacement collected by a single draw-wire displacement sensor under zero load conditions. This is the stiffness temperature correction factor. For the first The difference between the field temperature and the reference temperature under each loading level Reference temperature; When the ratio of the comprehensive stiffness index of the hanging basket of adjacent loading levels At that time, loading was paused and a comprehensive inspection of the hanging basket structure was conducted, including... For the first The overall stiffness index of the undercarriage basket under each loading stage.

5. The intelligent preloading method for hanging basket preloading test in bridge construction as described in claim 1, characterized in that, The calculation of the comprehensive structural response index includes: in, For the first The comprehensive structural response index under each loading level For the first The fusion weight of monitoring data For the first Under the first load level Measured extreme values ​​of monitoring data For the first The design allowable values ​​for class monitoring data, For the first The penalty index for monitoring data, The normalized index; when Immediately pause loading and send an alarm to the site.

6. The intelligent preloading method for preloading tests using hanging baskets in bridge construction as described in claim 5, characterized in that, The calculation of the loading rate adjustment factor includes: in, For the first Load rate adjustment factor under each load level This is the lower limit of the loading rate adjustment factor. The upper limit of the loading rate adjustment factor; The calculation of the target hydraulic loading rate includes: in, For the first Target hydraulic loading rate at each loading level This is the reference composite structural response index corresponding to the optimal loading rate. Adjust the sensitivity bandwidth to adjust the loading rate. As the reference hydraulic loading rate, The structural response acceleration penalty coefficient, For the first Load increments at each loading level For the formal pouring of the design load, For the first Load level attenuation factor under each loading level For the first The cumulative applied load under each loading level; Will After being processed by upper and lower limit amplitude control, the signal is input into the hydraulic control system.

7. The intelligent preloading method for hanging basket preloading test in bridge construction as described in claim 1, characterized in that, The spatial displacements of the key planes of the reconstructed hanging basket structure include: in, For reconstruction point Spatial displacement at that location, This represents the number of visual measurement points on one side. For the first Each visual measurement point is used to reconstruct the point. interpolation weights, For the first Measured displacement of each visual measurement point To introduce the number of structural correction modes, For the first Amplitude coefficients of the modified mode of the first structure. For the first The structural modal shape function of the modified structural mode at point The value at that location, For reconstruction point To the Euclidean distance between visual measurement points The distance decay exponent, For the first Local stiffness weighted correction factor at each visual measurement point For the first Local stiffness weighted correction factor at each visual measurement point For reconstruction point To the Euclidean distance between visual measurement points; when The absolute value of the difference between the displacement calculated by finite element theory and the displacement exceeds the allowable deviation threshold of the theoretical value and continuously covers... When there are one or more grid points, the corresponding continuous grid point area will be marked as a displacement anomaly area and an early warning and loading will be paused.

8. The intelligent preloading method for preloading test of hanging basket in bridge construction as described in claim 1, characterized in that, The calculation of the comprehensive judgment score for preload qualification includes: in, The comprehensive score for pre-compression qualification is as follows: For the first The penalty weight of monitoring data in the qualification determination, For the final load level Next The measured extreme values ​​of the monitoring data of the first class, The design allowable values ​​for class monitoring data, The residual-elastic deformation ratio penalty coefficient. This represents the maximum absolute value of the residual displacement at each measuring point after complete unloading. This is the theoretical elastic deformation. when When the preload is deemed qualified, The system will determine if the preload is unqualified and output a detailed report of the over-limit.

9. The intelligent preloading method for hanging basket preloading test in bridge construction as described in claim 3, characterized in that, The calibration values ​​for the elastic deformation at each measuring point are calculated as follows: in, For the first The calibration value of elastic deformation at each measuring point. To effectively increase the number of loading and unloading loops, For the first The second effective load / unload cycle occurs at the final load level. Next Measured displacement at each measuring point For the first Before the first effective load / unload loop loading... Initial displacement of each measuring point For the first Overload correction factor for each measuring point To apply the actual load to the final loading stage, The design load is for formal pouring.

10. An intelligent preloading system for preloading tests using hanging baskets in bridge construction, characterized in that, include: The stiffness index calculation module is used to formulate a graded loading and unloading scheme for the overload verification level and apply the load step by step. In the holding and stabilization stage of each loading level, the comprehensive stiffness index of the hanging basket is calculated based on the load and displacement increment data of each rope displacement sensor. The structural response index calculation module is used to extract the measured extreme values ​​of strain, displacement, and crack width at each loading stage and during the load stabilization phase, and to calculate the comprehensive structural response index. The hydraulic control module is used to calculate the loading rate adjustment factor based on the comprehensive structural response index of the current loading level at the end of each loading level, and to calculate the target hydraulic loading rate of the next loading level by combining the rate of change of the comprehensive structural response index of the adjacent loading levels with the current load level. The displacement anomaly judgment module is used to reconstruct the spatial displacement of the key plane of the hanging basket structure based on the actual displacement data measured by visual measurement points. The reconstructed spatial displacement is compared with the displacement calculated by finite element theory at the same loading level point by point. Continuous grid point areas that exceed the allowable deviation threshold are automatically marked as displacement anomaly areas and an early warning is triggered. The preload qualification judgment module is used to read the extreme values ​​of various monitoring responses of the overload verification level and the residual displacement after complete unloading after the specified holding time and all unloading procedures of the overload verification level, calculate the comprehensive judgment score of preload qualification, and judge whether the preload is qualified in combination with the set qualification threshold.

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