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The precast post-tensioned segmental columns react against lateral seismic loading with low residual displacement, predominantly because of the self-centring capability of post-tensioning strands. However, their application is still limited in high seismic zones due to their unknown behaviour during and following severe earthquake loading. In this work, experimental study is conducted to inspect the functionality of post-tensioned segmental columns after suffering severe damages. In earlier work by the authors, partial yield of central strands had been occurred during the unloading stage in the last cycle at 4% drift level. In current study, the experimental work is extended and the specimen retested under loading and unloading up to 4.0% drift. The results indicate that the first segment shows approximately 10 mm horizontal movement on the surface of foundation. However, the specimen showed identical strength at 4.0% drift level. In addition, using finite element method (FEM), a numerical study was conducted in order to investigate the influence of various parameters such as mild steel ratio, concrete strength, number of segments, post-tensioning force and axial loading. Finally, design recommendations were proposed for the yield displacement, ductility and correlation of residual displacement and displacement ductility of post-tensioned segmental columns with various aspect ratios. [ABSTRACT FROM AUTHOR]

Post-tensioned precast segmental bridge columns have shown high level of strength and ductility, and low residual displacement, which makes them suffer minor damage after earthquake loading; however, there is still lack of confidence on their lateral response against severe seismic loading due in part to their low energy dissipation capacity. This study investigates the influence of major design factors such as posttensioning force level, strands position, columns aspect ratio, steel jacket and mild steel ratio on seismic performance of self-centring segmental bridge columns in terms of lateral strength, residual displacement and lateral peak displacement. Seismic analyses show that increasing the continuous mild steel ratio improves the lateral peak displacement of the self-centring columns at different levels of post-tensioning (PT) forces. Such an increase in steel ratio reduces the residual drift in segmental columns with higher aspect ratio more considerably. Suggestions are proposed for the design of self-centring segmental columns with various aspect ratios at different target drifts. [ABSTRACT FROM AUTHOR]