What is the role of seismic bracing in steel structures, and which standard addresses this in detail?

• A. It is used to anchor to ground anchors.
• B. Seismic bracing provides lateral stability and redundancy; addressed in detail by AISC 341 (Seismic Design Provisions).
• C. It prevents corrosion.
• D. It is only for aesthetics; no standard.

Answer: (B)

Seismic bracing is about resisting horizontal earthquake forces and giving the steel frame lateral stability and redundancy, so the structure can deform in a controlled, ductile way without collapse. This means the mass and connections are arranged so demand from shaking is shared across braces, frames, and joints, preventing progressive or sudden failure. The detailed design requirements for how to achieve that performance are set out in AISC 341, the Seismic Design Provisions, which specify how braced systems are sized, connected, and detailing practices to ensure ductility and reliability under seismic loads. It isn’t primarily for anchoring to ground anchors, corrosion protection, or aesthetics.