You can search for information on applicable Codes and standards into the AISC (American Institute of Steel Construction) site: www.aisc.org
Also, who use to have information on the subject are the Structural Steel Specifications of renowned engineering and construction companies, such as Lummus, M.W.Kellogg, Davy McKee, Brown and Root, Sargent and Lundy, Black and Veatch etc.
Here in Brazil the state oil company, Petrobras, has issued a very good specification on structural steel. What about Ecopetrol?
Giovanni S. Crisi
Sao Paulo - Brazil