Geometric and material nonlinear analysis of prestressed concrete bridges with corrugated steel web(s)

Abstract

Concrete bridges with corrugated steel web(s) and prestressed by both internal and external tendons have emerged as one of the promising bridge forms. In view of the different behaviour of components and the large shear deformation of webs with negligible flexural stiffness, the assumption that plane sections remain plane may no longer be valid and therefore the classical Euler-Bernoulli and Timoshenko models may not be applicable. In the design of this type of bridges, both the flexural strength and ductility need to be carefully examined, which requires the estimation of full-range behaviour. In the study of this type of bridges, an analytical sandwich model and its finite element model for geometric and material nonlinear analysis are developed. The model accounts for the interaction between the axial and flexural deformations of the beam. The model uses the actual stress-strain curves of the materials (i.e. steel bars, prestressing tendons, steel web and concrete) and considers the path-dependence of these materials. With a nonlinear kinematical theory, a complete description of the nonlinear interaction between the external slipping tendons and the beam is obtained. Different rotations are assigned to the flanges and corrugated steel web(s). The numerical results obtained are compared with experimental results for verification. An extensive parametric study is undertaken to clarify the effects of various parameters on the flexural strength and ductility. Some design recommendations are also obtained based on the full-range analysis.