Experimental and numerical investigation of seismic performance of prefabricated double-column piers used in accelerated bridge construction

The socket connection has been considered to be an effective connection for accelerated bridge construction (ABC) due to its promising advantages, i.e., higher construction tolerance rate, simpler connection method, easier quality control method, and better seismic performance when the socket depth is sufficient. To further facilitate the promotion of socket connections, a novel double-column piers system with socket connection was proposed, and the prefabricated piers and adjacent elements are connected using Ultra High-Performance Concrete (UHPC) grouting. Three 1:3 scale double-column pier specimens using novel type socket connection, ordinary grouted corrugated duct connection, and cast-in-place connection, respectively, were subjected to pseudo-static tests, aimed to compare the effects of connection methods on the damage development, failure mode, strain distribution, and seismic performance of the double-column pier. The test results indicate that all three double-column piers with three different connection forms exhibit good seismic performance, with the failure mode being the fracture of the longitudinal rebars of the piers. Compared with the piers fabricated with the other two connection forms, the piers with socket connection feature less residual displacement, and the damage is mainly concentrated at the bottom of the pier. Additionally, numerical analysis models were devel-oped and validated for the socket-connected double-column piers to facilitate further research in this area.