Implementation in Practice

Research Implemented in Practice


BRBF-Es: 5-Level Mixed Use Complex in Palo Alto, CA

by ZFA Structural Engineers

The recent design and subsequent construction of a 5-level (3 levels above ground) mixed use steel building in Palo Alto, CA, by ZFA Structural Engineers, represents the world’s first BRBF-E seismic system. BRBF-E configurations using ductile beam splices were first developed by Dr. Gary Prinz (at the University of Arkansas) and Dr. Paul Richards (at Brigham Young University) to overcome architectural challenges imposed by many steel seismic systems. Additionally, BRBF-Es provide a viable alternative to EBF configurations having link-to-column connections which are susceptible to weld fractures during seismic loading.

Architectural constraints can create unique challenges in the seismic design of steel buildings, requiring a balance between unobstructed views, accommodation of passageways, and adequate lateral resistance. The developed BRBF-E configuration now implemented in practice uses ductile beam splices and buckling-restrained braces in eccentric configurations to provide lateral stiffness and accommodate architectural features, while simplifying frame detailing and construction. BRBF-E research conducted at the SSRL aided ZFA Structural Engineers during the design process and aided county officials in approving the new frame configurations.