Load transfer mechanism of precast concrete piers with demountable connections: Fid-Bau Portal

Load transfer mechanism of precast concrete piers with demountable connections

Zhou, Qiang / Liu, Yuqing / Li, Yongjun

Highlights • A novel demountable connection for precast bridge pier-pile cap joint is proposed. • The load from concrete pier to pile cap is transferred by steel-steel connection. • Pseudo-static capacity test and numerical analysis of pier specimens are conducted. • Failure modes of connection joint are investigated. • Load transfer mechanism and characteristics of the connections are revealed.

Abstract To investigate the replacement or rehabilitation of precast concrete piers, a novel demountable steel-concrete composite connection with notched perfobond connectors was proposed for the pier-pile cap joint. In the proposed connection, a bolted mechanical connection is used to connect the longitudinal reinforcing bars and steel plate, which is bolted to the pile cap through pre-stressed anchor bolts. Pseudo-static capacity tests of two half-scale specimens were conducted with different axial compression ratios, and the experimental results were verified by nonlinear finite element analysis. The lateral force-displacement curves, failure modes of connection joint, stress of steel plates and connector-concrete slip were compared and discussed. Furthermore, the internal load transfer mechanism and characteristics were revealed. The results indicate that the precast pier with the proposed connection realizes the rapid assembly and demountability. Specimens present flexural failure, and damage appears at the bottom of the pier columns but above the steel jacket. The connection steel plates and bolted connection remain intact as expected. The stiffness, capacity and failure process in numerical analysis agree well with the experimental results. The notched perfobond connectors set on the base plates effectively transfer the force from the concrete column to the base plate, and enhance the base plate-concrete connection and bending resistance of the base plate.