Seismic Resistance of Bridge Piers Based on Damage Avoidance Design

摘要

A generalized displacement-based seismic design methodology is proposed forbridge structures with rocking piers. Damping is assessed based on the energy radiated (lost) on each impact. For a given pushover curve and effective viscous damping, the expected seismic displacement may be predicted by comparing it to the elastic design spectra (demand). To validate the proposed design philosophy, the seismic performance of a near full-size precast concrete rocking column substructure was investigated. Under large lateral (rocking) displacements, no damage to either the concrete column, connection or foundation was observed. The strength and stiffness was observed to remain the same after many cycles of loading. A complete force-deformation model for the rocking column accounting for: structural flexibility (pre-rocking), rigid body kinematics (post-rocking) and the prestressing action of the tendons is proposed. Good agreement between the predictive theory and the experimentally observed force-deformation results was demonstrated.