Development of Effective Designs for Composite Bridges in Seismic Areas

Abstract

The design and construction of steel-concrete composite bridges using prefabricated modules offers a wide range of advantages, especially considering situations with tight completion times or challenging crossings. Transportation and manoeuvre activities are facilitated by using modules, which do not exceed the gauge requirements. Steel girders may be divided into segments and welded on site. Smart design provides easy assembling of the deck modules. VTR®, VFT® and VFT-WIB® are solutions for composite bridges using a high degree of prefabrication, proposing different technologies.

The VTR® system uses steel box girders in longitudinal direction as main girders, the deck is made of prefabricated concrete cross beams and pre-slabs. All modules are connected via additional reinforcement and in situ concrete at the joints.

VFT® and VFT-WIB® are systems using prefabricated composite girders typically made of reinforced concrete and halved hot rolled profiles or welded steel plates. The shear connection is achieved through composite dowels, created by a cut along the web of the steel section according to a specific geometry.

Such systems of composite bridges can be successfully applied in seismic areas. These solutions have been developed in practice as a modern method of bridge construction by introducing them into frame-type structural systems, integral and semi-integral bridges, which offer a number of advantages both in terms of structural behaviour to static and dynamic actions and in terms of reduced lifetime maintenance costs. This paper presents briefly the description of these system and case studies for VTR® bridges.