The Tsukuhara Extradosed Bridge near Kobe

The concept of “extradosed” bridges, where the stay cables are functionally similar to external post-tensioning cables, was introduced by Jacques Mathivat in 1998. The Tsukuhara Bridge, part of a road network with the Akashi-Kaikyo Bridge, is the second application of this technique by the Japan Highway Public Corp. A decade ago, bridges with a 180 m center span were mostly cable-stayed or massive box-girder bridges, but the extradosed concept can be applied to such span lengths, resulting in lower construction costs. The extradosed design was also felt to fit better visually with a nearby cable-stayed pedestrian bridge.