Shaking table test for externally-hung self-centering rocking wall structure

Abstract

This paper proposes an innovative externally-hung self-centering rocking wall (ESRW) structural system for retrofitting existing reinforced concrete structures. Reinforced corbels are installed on the columns of an existing structure to which rocking walls having unbonded post-tensioned tendons are connected using H-shaped connectors. The seismic performance and self-centering ability of the ESRW were investigated through a series of shaking table tests. For comparison, an unretrofit control structure (UCS) was also tested. The UCS was severely damaged under peak ground acceleration (PGA) = 1.2 g test conditions: some reinforcing bars were fractured and the UCS was close to collapse. For the ESRW, the damage was significantly reduced: there were only minor cracks appearing at PGA = 1.5 g test conditions and no damage appeared at the corners of the rocking walls. The maximum story drift and residual deformation of the ESRW were reduced 88% and 92%, respectively, relative to the UCS test. The ESRW structure showed desirable seismic performance and self-centering characteristics during shaking table tests.