Francis T.K. Au
Professor and Head, Department of Civil Engineering
The University of Hong Kong
Hong Kong, China
Title: Design Issues of Prestressed Concrete Bridges with Corrugated Steel Webs
Biography
Biography: Francis T.K. Au
Abstract
Prestressed concrete bridges with corrugated steel webs have emerged as a promising bridge form due to their remarkable advantages such as efficient prestressing of concrete, high buckling strength of steel webs and lightness. The behaviour of this type of bridges is quite different from that of conventional prestressed concrete bridges. The presentation will focus on the investigations of the full-range and long-term behaviour of these bridges. A sandwich beam theory was developed to investigate both the static and dynamic behaviour numerically. In the development of numerical models, special emphasis was placed on the modelling of corrugated steel webs, external prestressing tendons, diaphragms, and the interaction between web shear deformation and local flange bending. The numerical models were verified by tests. By using the numerical models proposed, the static service behaviour, dynamic properties and long-term behaviour were studied. The sectional ductility, deformability and strength were evaluated by nonlinear analysis taking into account the actual stress-strain curves and path-dependence of materials. The failure mechanisms were studied experimentally and numerically for more accurate evaluation of safety-related attributes such as ultimate load, ductility and deformability. The formation of plastic hinge and its size were also studied thoroughly in view of their importance in the prediction of full-range behaviour. The long-term behaviour was also studied numerically and experimentally. Some design recommendations are provided here.