AASHTO LRFD Strength III for steel girders design

[Brad_SoKno]

Does AASHTO LRFD Strength III apply to steel girder design, or is it only applied to substructure design?

 

[Lomarandil]

Absolutely applies to steel girder (or any superstructure) design. Some of the non-strength load combinations only apply to certain elements or limit states, but strength generally applies across the board.

 

[BridgeSmith]

It's certainly applicable to steel girder superstructure design, but Strength III is usually only critical during construction on a steel girder bridge, and sometimes affects the design of crossframes at the piers on long spans (which have to transmit the wind loads on the superstructure from the deck to the bearings.

 

[Brad_SoKno]

Thanks y'all... I thought it was applicable, but the software I'm using (LEAP Bridge Steel) didn't include this load combination even though I applied a wind load.

 

[Lomarandil]

True. I'm coming from the perspective of an engineer tasked with erecting/demo/rebuilding these bridges where we get into pickles when the permanent designer took that logic too far. But Rod is correct.

Strength III also tends to combine with akew effects if present. Less relevant to straight bridges