Seismic Resilience Enhancement of Irregular Space Structure Using Friction-Damped Self-Centering Tension Braces

A variety of self-centering devices and structural systems have been proposed and investigated in recent years to eliminate or reduce postearthquake repair, but so far their applications are still very limited. This paper reports the seismic resilience enhancement of an irregular space structure by using friction-damped self-centering tension braces (FSTBs). First, the configuration, performance, and numerical model of FSTBs are introduced, and then a seismic design procedure for enhancing the seismic capacity of a torsional irregular structure is proposed. Taking the terminal building at the Harare Airport, a lifeline project in Zimbabwe, for example, unidirectional and three-dimensional nonlinear dynamic analyses were conducted on the building designed with and without FSTBs. The result shows that FSTBs can significantly reduce both story drifts and residual story drifts of the bottom reinforced concrete frame and displacements of the steel roof. To this end, the field assembly of FSTBs is briefly reported. The presented study provides references to the use of self-centering devices in seismic resilience upgrades of important engineering projects.