Seismic performance comparison between force-based and performance-based design as per Canadian Highway Bridge Design Code (CHBDC) 2014

Abstract

Performance-based design (PBD) was first introduced in Canadian Highway Bridge Design Code (CHBDC) in 2014. Performance-based design is the design that meets multiple performance criteria under different earthquake hazards. To investigate the impact of changes in CHBDC 2014, a four-span concrete highway bridge is designed and evaluated using force-based design (FBD) and PBD methods as per CHBDC 2014, and FBD method as per CHBDC 2006. By incorporating soil–structure interaction (using p–y curves) nonlinear pushover and dynamic time history analyses are conducted to assess the seismic performance of these bridges. Maximum strains of concrete and reinforcing steel are compared among the three designs to determine their performance levels. It is concluded that PBD (CHBDC 2014) is highly conservative compared to FBD (for both CHBDC 2014 and 2006). For the three-level PBD approach, the design is governed by the criterion of reinforcing steel not yielding under the design earthquake (with 475 years return period).