Study on Seismic Performance of Rectangular Pier with New-Type Socket Connection

For the precast segmental piers of rectangular cross-section in urban viaducts, a new type of socket connection is proposed, namely connecting the pier shaft with the pile cap via a socket protruding from the top of the pile cap. To study the seismic performance as well as the effectiveness of the details of the presented socket connection, two specimens with this type of connection (one with the socket depth of 1.0D and the other with the socket depth of 0.8D, D refers to the side length of the rectangular cross-section in loading direction) and one monolithic cast-in-place specimen were prepared, and the concrete of high strength and high toughness was used for seam filling. Quasi-static tests were conducted to analyze and compare the key indexes of the specimens, including the hysteretic curve, skeleton curve, energy dissipation capacity, residual displacement and strain of reinforcement in pier shaft. The results indicate that the restriction provided by a socket depth of 0.8D approximates that provided by a socket depth of 1.0D. The socket depth can be increased without consuming extra concrete in the pile cap, and the embedding effect is also sound. For the pier with new-type socket connection, the pier base is a damage-sensitive area, rather than the seam and pile cap. The seismic performance of the pier with this new-type socket connection is similar to that of the integral cast-in-place pier, but the new-type socket connection can alleviate the loads on the reinforcement in the base of pile cap, thereby reducing the cracking risk of the pile cap. © 2022, Journal Press, China Railway Bridge Science Research Institute, Ltd. All right reserved.