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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. [ABSTRACT FROM AUTHOR]

This article aims to describe an automatic calculation algorithm developed for the analysis of reinforced concrete and / or prestressed concrete cross sections. The sectional analysis consists in the generation of two characteristic curves: the bending moment - curvature (M-1/r) and the axial force - bending moment (N-M), the calculation approach and the implementation of the algorithm being briefly described by the mathematical equations used. To verify the calculation algorithm, the results were compared with those obtained from experimental tests in the laboratory but also with numerical simulations using commercial computational software based on the finite element method (FEM). The algorithm was written in the MATLAB programming language. The results obtained with the developed algorithm show conservative results when compared to the experimental ones. Moreover, the bending moment resistance for prestressed concrete columns using bonded tendons is better estimated with at least 10% when compared with the one obtained with a fiber based cross section nonlinear analyses. [ABSTRACT FROM AUTHOR]

Reinforced concrete flat slab systems are supported to columns directly without beams. In this analytical study, a structure which has reinforced concrete flat slab with four storey is investigated under earthquake effect. The structure was analyzed by three different methods to compare bending moments in columns and flat slabs. In this study, explanatory information about flat slab systems is presented and different types of solution methods which are adopted our countries specification was compared through a structural example under the horizontal loads. Under the influence of horizontal earthquake forces; selected bearing system have been analyzed by the equivalent frame method, called the moment transfer coefficients method developed by Ünlüoğlu and finite elements method based SAP2000 software. The result of comparing the findings obtained from different solution methods to each other is presented with the help of column top and bottom moments in all floors, flat slab bending moments in inner and edge column strands, tables and graphs. According to this, the method developed by Ünlüoğlu using moment transfer coefficients and the results obtained from finite elements based SAP2000 software are very close to each other. The results obtained from the equivalent frame method are different from those result of the other methods of analysis. Because the equivalent frame method is an approximate method, it does not give as accurate results as the results obtained by the finite element method. However, the method developed by Ünlüoğlu may be an alternative to the finite element method. [ABSTRACT FROM AUTHOR]