"R" value for tension only bracing in steel frames buildings
"R" value for tension only bracing in steel frames buildings
(OP)
What "R" value (overstrength/ductility coefficient) per '97 UBC would I use for the seismic design of a steel framed building (typ 1 story metal bldg)in the opposite direction of the moment frames, where tension only bracing is used to resist lateral forces. Thanks!





RE: "R" value for tension only bracing in steel frames buildings
However, if you are in zones 3 or higher or you are in zone 2 with an importance factor > 1, you cannot use a tension only brace system (see 2211.4, section 9.2.c for LRFD and/or 2213.8.2.3 for ASD)
Section 2210.2.1 outlines the fact that the steel seismic provisions in the UBC are only applicable to zone 2 (with I>1) and to zones 3 and 4. If you are lower than this, you can use a tension only brace.
RE: "R" value for tension only bracing in steel frames buildings