Current U.S. building codes and earthquake engineering practice utilize inelasticity in the seismic force resisting system to dissipate seismic energy and protect against collapse. Inelasticity in conventional structures can lead to structural damage distributed throughout the building and permanent drifts after the earthquake motion ceases which can make the structure difficult if not financially unreasonable to repair. A controlled rocking system has been developed which virtually eliminates residual drifts and concentrates the majority of structural damage in replaceable fuse elements. The controlled rocking system for steel-framed buildings consists of three major components: 1) a stiff steel braced frame that remains virtually elastic, but is not tied down to the foundation and thus allowed to rock, 2) vertical post-tensioning strands that anchor the top of the frame down to the foundation, which brings the frame back to center, and 3) replaceable structural fuses that absorb seismic energy as the frames rock.
The controlled rocking system is investigated and developed through analytical, computational, and experimental means.
This is a Ph.D. Dissertation from the University of Illinois at Urbana-Champaign