Seismic performance of self-centering precast segmental bridge columns under different lateral loading directions

Abstract

Self-centering precast segmental bridge columns (SC-PSBCs) have been intensively investigated in the past decade as one of prefabricated bridge components to expedite construction and improve seismic resilience. However, the application of SC-PSBCs is limited to the low seismicity areas due to insufficient knowledge about their seismic performance. In particular, the behavior of SC-PSBCs is not clear under multi-directional seismic excitations. In order to investigate the effect of lateral loading directions on the seismic performance of SC-PSBCs, five 1/10-scale identical SC-PSBC specimens with rectangular hollow sections were designed and tested under lateral cyclic loading and a constant vertical load. Each specimen was loaded at a specific angle with respect to the weak axis of the column section. The loading angles included 0, 30, 45, 60, and 90 degrees. The seismic performance of the specimens was evaluated and discussed using the test results. It was found that the SC-PSBC specimens were of good ductility, and the favorable self-centering capacity was obtained under orthogonal loading directions. Only considering the orthogonal loading direction in the design of SC-PSBCs is non-conservative since it may underestimate the local damage and residual displacement. The extent of prestress loss in each strand was very sensitive to the relative distance to the neutral axis depending on the loading directions. The equivalent viscous damping ratios of SC-PSBCs were in the range from 0.151 to 0.198 at a drift ratio of 4.0%.