Experimental Study on Seismic Performance of Precast Piers with Socket Connection
This study investigates the effects of different connection details,axial compression ratio and socket depth on the seismic performance of the precast segmental piers with socket connections(socket piers for short).One group of cast-in-place piers(CIP piers)and three groups of socket piers were prepared for the quasi-static test.Multiple factors,including the failure mode,hysteretic curves,skeleton curves and eigenvalues,energy dissipating capacity,stiffness,residual displacement,and longitudinal reinforcement strain were compared to analyze the difference between the seismic performance of the socket pier and the CIP pier as well as the seismic performance of the two types of piers after adding steel tenons for structural modification.The results show that the socket and CIP piers exhibit approximate failure mode,damage scale,load bearing capacity,energy dissipating capacity,residual displacement,and the distribution of reinforcement strain along girder depth.With an improved axial compression ratio,the socket pier displays a load bearing capacity greater than that of the CIP pier,while the ductility and cumulative energy dissipating capacity are lowered,the residual displacement during the damage process is less than other structural members,indicating a reliable self-centering ability.Improving the socket depth will lead to the increase of both the load bearing and energy dissipating capacity of the pier.Adding steel tenons at the bottom of the pier can raise the connection between the precast pier and pile cap,while the load bearing capacity,ductility,and energy dissipating capacity of the socket pier keep at the same levels of the CIP pier,which is favorable to improve the energy dissipating capacity of the socket pier,and also means sound seismic performance.