Effective Width of Composite Beam in Cable Stay Bridge

[willowman]

Hi everyone,

I wanted to understand if anyone had experience designing composite ladder decks for cable stayed bridges.

There are plenty of design examples for standard ladder deck composite bridges but I have not been able to find any worked examples of a cable stayed bridge.

I have uncertainty regarding the application of the Eurocode 4 effective width process to account for shear lag. My uncertainties are:

1. Eurocode 4 provides a definition for the effective width of the concrete flange based upon the span of the beam. For a cable stayed bridge, the supports are the stay cables and they are not 'real' supports under live loading...Furthermore, if the spacing between cable stays is used as the span of the main beam then only a small effective width is obtained...which seems unreasonable given that the main edge beams of the ladder deck are of considerable depth.

2. Unlike typical ladder deck bridges (which just span between piers etc), a cable stayed bridge deck is under large compression forces due to the inclination of the stay cables. It seems to me that Eurocode 4 does not make reference to how such an axial force in the deck could impact the effective width.

Can anyone recommend a useful reference text on this topic? I have been using 'Cable-stayed Bridges' by Holger Svensson.

Thanks,