Le Dual-BRB, une alternative pour un comportement sismique ameliore.

摘要

Concentrically braced steel frames (CBFs) in chevron or split-X configuration are one of the most used bracing systems in North America. In medium or low-rise structures and moderate seismic areas those systems can achieve satisfactory behaviour. Contrarily, for taller buildings and under strong seismic ground motions CBFs appear to be prone to soft-story response because of the more pronounced contribution of the higher vibration modes, which can lead to dynamic instability. Also, significant structural damage is observed, such as low cycle fatigue failure of diagonals or net section fracture of the connections. Those failures are mainly attributed to the poor hysteretic response of the steel bracing members under cyclic loading. To prevent those phenomena North American standards have introduced building height limits for those systems. In CSA-S 16-01, a 12-story limit has been imposed for concentrically braced frames with limited ductility. (Abstract shortened by UMI.)