Performance of Damage Avoidance beam-column joint subassembly subjected to bi-directional earthquake excitation
This paper investigates the experimental application of a newly-developed Multi-level Seismic Performance Assessment (MSPA) methodology. Firstly, MSPA enables each seismic performance requirement to be verified using a single earthquake record, and secondly by applying the earthquake records for the different performance criteria in an increasing severity order, all seismic performance requirements can be verified using a single specimen. This idea is applied in this paper in order to verify the three seismic performance requirements (i.e. immediate occupancy in a moderate earthquake, reparability after a rare earthquake, and life safety in a rare earthquake) for a reinforced concrete frame building designed for damage avoidance. A 3D beam-column joint subassembly designed for damage avoidance is subjected to biaxial quasi-earthquake displacement (QED) tests using earthquake records identified to represent the hazard levels corresponding to the three seismic performance requirements. The subassembly performed well reaching drifts up to 4.7% during the final stage. Although some repairable damage in the form of minor spalling, cracking, yielding of the post-tensioned tendons and energy dissipaters occurred, the subassembly did not collapse. The subassembly met each of the three seismic design criteria, verifying the superior behavior of structures constructed according to the emerging damage avoidance design (DAD).