Extradosed bridges in Japan

Extradosed bridges are similar to cable-stayed bridges in that stay cables are used for strengthening. The concept of extradosed bridges has been taken up in Japan, where several bridges of this type have now been constructed. This paper shows five extradosed bridges that were designed and built by the author, and explicates the difference between extradosed and cable-stayed bridges in terms of structural aspects. In addition, the method of design for stay cables in Japanese specifications is introduced.