Lateral buckling of prestressed concrete girder

[Daniel_]

Hi, Im looking for any reference on how to cope with lateral stability for precast members with or without prestress (but mainly prestressed).
Any code reference would really help but as Im Eurocode based engineer, I would prefer Eurocode applicable solutions.
Ive found some forumla that basically recommends ratio between flange width and depth but that seems like oversimplification that results in uneffective "overdesign". Also Eurocode doesnt specificaly says you can apply those equations (below) to prestressed members. Im not happy with what dimension recomendations it gives.

Im designing cca 25m long prestressed girders with distance cca 6m / 12m for warehouse roof.

 

[r13]

Wouldn't a buckling check provide better indication, and confidence?

 

[Daniel_]

It would but Im looking for some reference how to calculate it if the member is prestressed. I cant find any reasonable reference on how to calculate it for concrete at all.

 

[r13]

You can googling around with the phase "buckling of prestressed concrete beams". Here is one maybe helpful, but seems a little aged. Link

Here is part 2. Link

 

[jorton]

I second r13. The Mast articles are good. Lots of additional guidance has come out in the last 10 years. I think PCA and NHI both provide some guidance in addition to the many recent research papers. Florida DOT has a mathcad sheet that is available to the public.