Seismic performance of precast double-column pier with UHPC-filled socket connections

Abstract

Precast piers have been extensively investigated and applied in low seismic intensity areas, owing to the faster construction speed, limited traffic interruption, and environmental friendliness. However, few studies and engineering practices of the precast double-column piers (PDPs) located in high-intensity seismic areas have been reported. Therefore, in this study, a novel socket connection filled with ultra-high-performance concrete (UHPC) was proposed for the PDPs. The socket connections with concrete filled steel tube (CFST) are used to enhance the strength of the column-cap beam joints, at the same time the socket connections with the tooth-shaped shear keys are adopted at the column-footing joints to reduce the required anchorage length. The PDP with a scale ratio of 1:3 was constructed and then tested under the quasi-static load to investigate its seismic performance. Finally, a simplified analytical model of the socket connections was proposed based on the concept of the elastic foundation beam. The test results demonstrate that the damage of the specimen PDP was mainly concentrated at the bottom of the columns, and the damage at the damage ends of the PDP specimen was severer than that of the cast-in-place (CIP) specimen. The load-bearing capacity of the PDP is slightly higher than that of the corresponding CIP specimen, while the energy dissipation and displacement ductility of PDP are slightly smaller than those of the CIP specimen. The proposed model could accurately and efficiently capture the hysteretic behavior of the proposed PDP with socket connections.