Multi-tiered bracing systems are not addressed in the CSA-S16-14 standard. In Canada, structural engineers who design these systems rely on scientific papers published by researchers or on American standards to compensate for this lack of requirements.
The good news is that the new version of the CSA S16 standard, released in 2019, addresses the design of multi-tiered bracing systems, which finally provides structural engineers with better guidance in designing these elements.
In fact, Clause 22.214.171.124 guides us in the design of multi-tiered bracing. This clause specifies restrictions when designing multi-tiered bracing. It also describes requirements for other structural elements, like the building’s struts and columns.
For example, according to Clause 126.96.36.199.2, chevron bracing must have out-of-bracing lateral struts at the brace-to-strut connections to stabilize it.
However, in most industrial buildings, clearance to install the major equipment is required, eliminating the out-of-plane bracing structural element. To address this issue, Clause 188.8.131.52.3 explains how to overcome the lack of such lateral support when designing structural elements, ensuring the system will resist the lateral loads.
These new clauses indicate that structures can be optimized while remaining safe and cost-effective.
Do you have design examples to share? Interpretations to confirm? If your work involves industrial building design, and you have constraints to consider when choosing a structural system, we would be happy to talk to you about them.