Finite Element Model Updating of RC Bridge Structure with Static Load Testing: A Case Study of Vietnamese ThiThac Bridge in Coastal and Marine Environment

Abstract

Diagnostic load testing refers to the use of the measured historical responses of the structure in the field data to better understand its dynamic and static structural behaviours. It is important and necessary to predict the health state, load capacity, and aging of the structure by updating the finite element (FE) model, which can give useful information to aid the design of retrofits and the maintenance of the existing bridge in the future. The paper presents an update of the full-scale FE model for the reinforced concrete (RC) bridge structure over the seawater river based on the experimental strains under the static load testing in which the representative FE model of the actual structure is determined from the optimisation procedures. The optimisation variables are applied, including the cross-sectional properties and concrete material calibrated through the genetic algorithm (GA) optimisation in the MATLAB software, which interfaces with the FE modelling in the scripting of the SOFISTIK TEDDY software automatically. The bending moments at the mid-span of the RC girders are determined in the FE modelling to compute stresses, which are compared with the measured stresses through optimisation scenarios with a percentage error of the objective function less than 10%. The measured data of concrete strains are recorded from reusable strain transducers installed on the mid-span girders for every bridge span, which are used to calibrate the bridge model in static load testing. The novelty of the solution is to implement innovative techniques using field data as an improved approach for calibrating automatically the analytical FE model parameters of all RC spans of the bridge until its static behaviours are very similar to those of the actual bridge. The final updated FE modelling is used to apply truck load configurations according to bridge design standards such as the AASHTO specifications, which can predict the load limits of the existing bridge structure more accurately and reliably. These proposed approaches can be applied to large bridges as well as complex structures with supporting FE analysis software and data processing software.

Automation of structural health monitoring (SHM) system of a bridge using BIMification approach and BIM-based finite element model development

“…The results of both static and dynamic measurements are compared with the numerical calculations and the percentage difference in results is compared with the findings of EC. Whereas the comparison of permanent and total deflections constitutes from 0 to 6%, therefore, meets the standard condition of not exceeding the level of 10% 29 , 56 . Such results prove that the stiffness of the spans is consistent with the values of the calculation model, thus validating the FE model of the bridge and showing the sufficiency of existing sensors measuring the static parameters of SHM system.…”

“…Further, the consistency of the stiffness values is also checked. Thus, a comparison of permanent and total deflection is carried out and checked against the standard condition of not exceeding the level of 10% 29 , 56 . In this way, load-testing results are justified as a source of FE model updating (Section " Static load test results ").…”

“…Both linear and non-linear FEA analyses are popular across the board to carry out the said comparison, therefore, the results obtained from many load tests have focused on verifying bridge provisions of the design codes, procedures, and FEA models 24 – 28 . Nguyen and Gerges et al used FE modelling and truckload configurations to predict load limits accurately and reliably and also attempted to monitor bridge health state, load capacity, and aging of a structure 29 , especially in the case of diagnostic load testing.…”

Integration of Bridge Health Monitoring System With Augmented Reality Application Developed Using 3D Game Engine–Case Study

“…These numerical analysis results are sometimes validated by load tests which have focused on the improve-ments in analysis and design procedures, evaluation of the bridge design code provisions, and tracking the in-service behavior of bridges [5], [6]. The effective utilization of Finite Element Analysis (FEA) results is based on the analysis type, structural design procedures, and Finite Element (FE) model updating of the bridge structure [7]. After the validation, critical values of the resulting parameters are pointed out for the identification of the locations and types of sensors [8].…”

Structural Health Monitoring for Dębica Railway Steel Arch Bridge in Poland

“…Diagnostic bridge testing is used to understand the distribution of the load throughout the structure, while long-term health monitoring is used to track changes over time in potential structural problems. For testing bridge structure, in which static, quasi-static and live loads can be applied to collect historical structural responses in the field used for load ratings and predicting load limits and overload via the finite element (FE) model calibration [2]. The FE model updating can be a powerful tool for determining the load-carrying capacity of existing bridges, used for the SHM system.…”