Characterization of the static and dynamic response of a post-tensioned concrete box girder bridge with vertically prestressed joints showing vertical deflections due to concrete creep deformation

Abstract

Abstract Time-dependent phenomena, such as creep of concrete, induce stress/strain redistributions in post-tensioned concrete bridges that must be taken into account during their design. The underestimation of time-dependent effects can negatively influence the load-deformation behavior of this bridge typology, leading to unexpected deformations of the deck, serviceability issues, and collapses. Numerical models able to simulate time-dependent phenomena should also be used to properly conduct the structural assessment of existing post-tensioned concrete bridges. However, before the introduction of specific materials’ constitutive laws to account for time-dependent phenomena, numerical models should be calibrated and validated according to the information gathered by testing the structures they represent, to carry out reliable numerical simulations. The paper presents the preliminary results obtained from the structural assessment of a post-tensioned concrete box girder bridge with vertically prestressed internal structural joints, which exhibits marked deflections of the box girder. A numerical model of the case study bridge was constructed, hence non-destructive and partially destructive tests were carried out on the structure to characterize its structural response. Overall, the resulting numerical model represents a solid basis for conducting more advanced analyses, such as those investigating the influence of time-dependent phenomena on the long-term structural response of the structure.