Shake-Table Test of a Full-Scale 4-Story Precast Concrete Building. I: Overview and Experimental Results

The level of structural damage and the associated economic impact caused by recent earthquakes worldwide have spurred an increased interest in high-performance seismic-resisting systems that can sustain severe earthquakes with minimal damage. A particularly efficient high-performance wall system consists of precast concrete panels vertically posttensioned to the foundation with unbonded posttensioning steel. The system relies on the vertical unbonded posttensioning steel for flexural strength and recentering, while mild bonded steel bars provide energy dissipation and additional flexural strength. Experimental results are presented from a dynamic test on a full-scale 4-story precast concrete building that utilized unbonded posttensioned (UPT) walls in one direction and bonded posttensioned concrete frames in the orthogonal direction. The excellent performance of the test building in the wall direction of response, exhibiting minimal damage and no residual deformations, confirms that UPT walls are a viable alternative to conventional RC structural walls.