Shake Table Studies and Analysis of a PT-UHPC Bridge Column with Pocket Connection

Abstract

This study conducts shake table studies and analysis of a large-scale novel posttensioned (PT) precast bridge column connected to a precast footing with a pocket connection. The primary objective is to develop a resilient square precast bridge column with minimal residual lateral displacement and plastic hinge damage when subjected to strong earthquakes. Another objective is to evaluate a column-footing pocket connection. The column is posttensioned with unbonded carbon fiber–reinforced polymer (CFRP) tendons to eliminate permanent drifts. To mitigate seismic damage, ultra-high performance concrete (UHPC) is used in the plastic hinge zone of the column. The column model is subjected to the 1994 Northridge-Rinaldi earthquake record with increasing amplitudes until failure. Experimental results show that the drift ratio and displacement ductility capacity of the column are 6.9 and 13.8%, respectively, and the residual displacement is negligible. Furthermore, the pocket connection is effective in forming the plastic hinge in the column with no connection damage. Another finding of the study is that available fiber element models lead to close correlation between the measured and calculated responses.