Bolted connections, used in seismic‑force‑resisting systems (SFRS) for which the seismic design loads are based on a ductility‑related force modification factor, Rd, greater than 1.5, must satisfy Clause 27.1.6 of S16‑14 as well as other pertinent requirements that apply to bolted connections. In accordance with Clause 27.1.6, these bolted connections shall: (a) have pretensioned [...]
In order to simplify the procedure for determining earthquake loads and effects in regions of low seismicity, a simplified static procedure has been introduced in National Building Code of Canada 2015. In this article, the force magnitude of a building in terms of the base shear, as determined in accordance with this simplified procedure, is compared [...]
Braces in a tension-only braced frame are designed to resist, in tension, 100 per cent of lateral shear forces in the braced frame. Since the resistance of braces acting in compression is ignored in the design, tension-only braced systems must be direct-acting and concentrically braced frames. Over the last 25 years, ductile design provisions for tension [...]
Advantages of HSS as braces The popularity of hollow structural section bracing stems from two facts: a) Square and circular HSS do not have a minor axis Typically, the compressive resistance, Cr, for a brace is considerably smaller than its tensile resistance, Tr (for CSA G40.21 350W steel, Cr for a brace at the maximum permissible [...]
The discussion herein concerns ductile moment connections only and therefore does not apply to connections used in moment-resisting frames in ‘conventional construction’. Following the Northridge earthquake in 1994, North American standards mandated physical testing as the basis for design of beam-to-column connections in ductile steel moment-resisting frames. This requirement was adopted as an interim measure until [...]
Seismic Corner - Advantage Steel Issue No. 50A system developed for seismic resistanceCommon lateral-load-resisting systems, such as rigid frames, concentrically braced frames and shear walls, have traditionally served to resist wind effects and provide stability in general...
Seismic Corner - Issue No. 51This article discusses the ductile brace-end rotation requirements for Type MD and some of Type LD braced frames...