Shake Table Studies of Precast Bridge Columns with a Novel UHPC Connection

A novel lap splice connection by ultrahigh-performance concrete (UHPC) was proposed to connect bridge columns with footings. The bond strength between UHPC and reinforcement was quantified by the genetic programming-orthogonal least squares tool. Then, an approach was advanced to guide the design of the proposed connection. Further, a 1/3.5 geometrically scaled bridge specimen was designed and tested on shake tables to validate the effectiveness of this connection designed by the proposed approach and to analyze seismic responses of the specimen. Test results revealed that the precast columns damaged in a flexural pattern reached a drift of 3.2% under the peak ground acceleration of 1.4 g. Moreover, most inelastic deformation and damage occurred above the column-footing connection segments which, designed by the proposed approach, remained barely damaged. Meanwhile, the strain concentration effect at the column bottom was less significant.