Comprehensive Review of Unified Performance-Based Design (UPBD): An Advancement of Performance-Based Seismic Design

The field of earthquake engineering has evolved significantly from conventional Force-Based Design (FBD) towards Performance-Based Design (PBD), aimed at ensuring predictable structural performance under seismic events. While PBD offers flexibility in addressing multiple performance objectives, early Displacement-Based Design (DBD) methods, particularly Direct Displacement-Based Design (DDBD), often focused solely on inter-story drift, neglecting explicit member-level performance criteria such as plastic rotation. Additionally, DDBD required iterative sizing procedures, increasing computational effort.

The Unified Performance-Based Design (UPBD) method was developed to overcome these limitations by simultaneously integrating drift and performance level criteria, providing non-iterative member sizing from the outset. This review examines the evolution from FBD to PBD and the emergence of UPBD, critically evaluates comparative studies, and highlights applications across RC frames, dual systems, high-rise buildings, and bridge piers