SHAKE TABLE TESTS OF SEGMENTAL BRIDGE COLUMNS WITH MATCH-CAST DRY JOINTS

To investigate the seismic performance of precast segmental bridge columns, an experiment including five concrete bridge columns was designed; among them three were precast segmental bridge columns and the other two were cast-in-place bridge columns. Through the shake table test under the same peak gravity acceleration (PGA), the seismic behaviors of the five concrete bridge columns were demonstrated including the dynamic properties, the damage process, the opening of the joints and the displacement response. Results showed that, for the three precast segmental bridge columns, significant flexural cracking occured at the joints in the plastic hinge zones while no cracks were observed in the body of segmental column. With the increasing of the excitation, the opening of the joints became larger showing the swaying phenomenon. The displacement response of the precast segmental bridge column was larger than that of the conventional cast-in-place reinforced concrete bridge column. The existing of energy-dissipating bars increased the stiffness, mitigated the displacement response, delayed the opening of joints and dissipated more energy. For the precast segmental bridge column with the bonded prestressing strands, the displacement response increased significantly due to the yielding of prestressing strands under large earthquakes.