The Structural Team chose buckling restrained bracing to reduce the acceleration during seismic response by a factor of 8. For instance, the 1st mode of vibration goes from actual (.25 g) to design acceleration (.03 g).

Buckling Restrained Braces (BRB) were chosen for our Lateral Force Resisting System (LFRS). BRB has three major components: steel core, bond-preventing layer, and casing.

The steel core resists the full axial force due to the bond-preventing layer. This causes the steel core to yield inelastically. The casing provides lateral support against flexural buckling of the core. It’s high ductility produces an energy dissipative behavior that lowers oscillations caused from seismic loads. This leads to a reduction in member size, simpler and smaller connections, and smaller foundation demands.

Since the damage from an earthquake is concentrated over a relatively small area, post-earthquake investigation and replacement are relatively easy.