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AISC forum question: In p. 234 of Ductile design of Steel Structures Bruneau, Uang, Whittaker McGraw Hill 1998 you see that a chevron shape with a bottom central equilibrating zipper is not labeled ZIP but STG (Strut to ground). There is exposed that as per one study by Khatib, ZIP bracings, that have not the zipper strut at the bottom level perform better against...