Pushover Analysis of Precast Segmental UHPFRC Bridge Columns with Unbonded Posttensioned Tendons

摘要

Cyclic loading tests were carried out to research seismic behavior of precast segmental ultrahigh-performance fiber-reinforced concrete (UHPFRC) bridge column with unbonded posttensioned (PT) tendons. Energy dissipation (ED) bars embeded in ultrahigh-performance concrete (UHPC) grout maintained continuous across segment joints and unbonded at the bottom joint. The equivalent method was proposed for ED bars with unbonded length and unbonded PT tendons to obtain the equivalent fiber section conforming to the flat section assumption. A method based on the equivalent plastic hinge model was given to conduct pushover analysis for precast segmental UHPFRC bridge columns. Test results showed that all the specimens exhibited no less than 8% drift capacities, which were remarked with the first fracture of ED bars. Compared with test data, the proposed model was validated to have good accuracy to provide lateral skeleton curve.