INVESTIGATION ON SEISMIC PERFORMANCE OF PRECAST PIERS WITH COMBINED CORRUGATED PIPE-UHPC SLOT CONNECTION

To promote the application of precast piers in high-intensity areas, this paper proposed a pier-cap beam joint with a novel connection configuration based on corrugated pipe and ultra-high performance concrete (UHPC) slot, designed the cast-in-place (CIP) joint and the joint with a corrugated pipe-UHPC slot connection pier (CP-USCP), and conducted pseudo-static tests. The experimental results show a ductile damage mode of the specimens. Moreover, the CP-USCP piers exhibit a bearing capacity of over 88% of the peak load at a large drift ratio (6%). Through numerical simulation analysis, the effects of longitudinal reinforcement strength, reinforcement ratio and the lap length of internal compensating reinforcement on the seismic performance of CP-USCP piers were discussed, respectively. The results indicate that the range of plastic hinge area decreases slightly with the increase of longitudinal reinforcement strength. A sudden change in the cross-sectional stiffness within the plastic hinge area of the pier occurs at a compensation lap length of 350 mm~750 mm, leading to an upward shift of the plastic hinge. When the lap length is increased to 800 mm~1000 mm, the plastic hinge is located at the bottom of the pier. Based on the test and simulation results, a formula for the required lap length of the internal compensation reinforcement is proposed.