New developments in steel and composite bridges

Abstract

Innovations are often initiated by bridge design. In this paper out of the large variety of new solutions and developments in bridge design, the focus is on three different subjects: Especially composite constructions made of structural steel and reinforced concrete adapt very easily to the most diverse situations and lead to efficient and beautiful bridges. The requirement of time effectiveness has driven solutions with prefabrication. First, a newly developed composite section with a trapezoidal steel web and horizontally lying studs is presented. Secondly, slender structures of thin plates are usually designed according to EN 1993-1-5. In order to adapt to an optimized overall curved shape in longitudinal direction the development of new buckling rules for non-rectangular steel panels is addressed. As a third point fatigue design, which is most relevant for the bridge dimensions, is addressed. Improvements by HFMI-treatment have been verified so that advantage can now be taken especially for high strength steels that allow a more slender design. The influence of the terms of application of HFMI-treatment on the quality has been investigated in a recent project. These different developments can lead to more slender, more efficient long living steel and composite bridges that satisfy future demands of increased sustainability.