Study on the evolution of structural response up to failure of prestressed concrete bridges curved of skewed in plan

Abstract

The subject of this work is to study the evolution of structural reponse up to failure of prestressed concrete bridges curved or skewed in plan, where bending and torsion are coupled. The paper describes a mathematical model for non linear mechanical analysis where bending shear and torsion interaction is taken into account in deformability and strength, in order to modelize prestressed concrete curved bridges throught a polygonal of straigth elements structurally defined by its cross sections. Applying this model, two prestressed concrete bridges are analyzed. The first one, is a skewed bridge simply supported, and the second one is a continuous nridge curved in plan. The theoretical results confirm that the structural response is strongly non linear in internal forces and displacements, showng that for several loading cases, linear analysis may give results in the unsafe side. Also, a parametric study on the influence of amount of longitudinal and trasverse prestressing is carried out and the unsuitability of sectional uncoupled models for calculating internal forces and displacements of this type of bridges is shown.