"Extradosed" bridges - references wanted

[Ingenuity]

I think it was fairly recent that Japanese engineers termed bridges as "EXTRADOSED bridges" for those that have cable stays with very short stay towers (tower height/span of 1/15 to 1/10). These bridges have an appearance that resembles cable-stayed bridges, but the structural characteristics are comparable to those of box girder bridges.


I have read several Japanese technical papers that state:

1. The girder height can be set shorter than that of standard girder bridges.

2. The stayed cables (prestressing tendons outside the girders) need no tension adjustment necessary for cable-stayed bridges, and can be treated as usual tendons in the girder bridge.

3. The height of pylons can be as half as those of cable-stayed bridges, therefore easier construction can be executed.

4. With small stress fluctuation under live load, the anchorage method for the stayed cables can be the same as that of tendon inside the girder, then the excess cost can be cut.


I am looking for additional technical references and experiences to this type of bridge design and construction. Any assistance would be appreciated.

TIA.