Design and construction of a launched steel girder bridge

Abstract

This paper describes the design and construction of the steel composite Bridge G4 as part of the recently completed Egnatia Motorway project in northern Greece. The bridge crosses a 180 m wide, 70 m deep valley situated in a seismic zone. Following a value engineering study, a three-span bridge with incrementally launched deck was found to provide the best option with minimal disturbance to the environment. Due to the relatively high seismic design acceleration, the superstructure is considered to float on the substructure by means of high damping lead rubber bearings restrained by mechanical dampers at abutments. This paper describes the design and construction of Bridge G4.