Accelerated viaduct construction

Abstract

Modern geometrical requirements for high capacity ground infrastructure, as highways or high speed train lines, imply increasing number of long tunnels and viaducts in mountainous countries. Moreover, for the sake of the environment, only some selected construction methods are eligible for sensitive areas. Among them, a very popular one for medium span concrete viaducts is the span by span construction with movable scaffolding system. The method can be easily adapted to any geometry and, from an environmental point of view, only the shadow of the deck is spoilt during construction periods. Since its first application in the Kettiger Hangbrücke, (Germany) in 1959, this construction method has been applied extensively all around the world. The paper will describe the pros and cons of the method and will explain in detail the last developments made in order to reduce to a minimum the critical path, increasing its competitiveness. New construction sequences, non-standardized structural details, static and dynamic tests, finite element model analysis and recent already built examples will be described to illustrate the possibilities of the method.