Roof Girder Design

[takiyasamsama]

I wanted to know how this roof support girder is determine? API doesn't specify any guideline so I'm thinking some other reference must have or this is entirely up to civil and structure calculation and analysis?

Thanks

 

[IFRs]

API 650 section 5.10 contains guidance including loads and load combinations, slenderness ratios and allowable stresses. Specifically for allowable stresses: The allowable strength of roof components shall be determined in accordance with the ANSI/AISC 360 using allowable strength design methodology (ASD). Most of these structures are relatively simple and are straightforward to to analyze.