Seismic performance of a precast pier with novel socket connection under the compound effect of compression-flexure-torsion

To clarify and improve the ability of fabricated piers with socket connection to resist composite loads such as compression, bending and torsion, a novel socket connection method for prefabricated piers combining grouting sleeves and sockets was proposed for application in ordinary cap. The damage characteristics and hysteresis energy dissipation performance of cast-in-place piers, fabricated piers with grouting sleeves, fabricated piers with sockets and fabricated piers with novel socket connection through quasi-static tests under compound loads, and the effect of socket height on hysteresis performance was analyzed with numerical simulation, and its application feasibility in shallow socket connection was discussed. The results show that the failure modes of the four specimens are the bending-torsional failures dominated by bending failure, among which the SU specimen has a slight phenomenon of pulling up, while the corresponding GSU specimen does not have this phenomenon, which is close to the RC specimen. The development trend of the shear force-pier top displacement skeleton curves of each specimen is relatively consistent. Due to the longitudinal steel bar of the GSU specimen is continuous, it has better overall performance, and its flexural load capacity is close to that of RC specimen, and is significantly larger than that of SU and GS specimens. The bending hysteresis energy consumption of the four specimens is relatively close. The torsional bearing capacity of the GSU specimen with the depth of the socket is ID and slightly higher than that of the RC specimen, and is significantly greater than that of other fabricated pier specimens. The torsional stiffness, ductility coefficient and energy dissipation capacity of the GSU specimen are greater than that of the other three piers. When the depth of the socket is 0. 5 times the cross-section width of the specimen, the flexural bearing capacity and torsional bearing capacity of the specimen with novel socket connection are higher than that of the cast-in-place RC specimen, which has a good ability to resist compression, bending and torsional loads, and can realize shallow socket connections. The results can provide an experimental basis for the application of fabricated piers under the combined action of compression, bending and torsion. © 2024 Chinese Vibration Engineering Society. All rights reserved.