Practical Bridge Code Calibration

The paper describes the calibration of the Ontario highway bridge design code and gives results. The method of calibration integrates traditional procedures, establishing some factors by judgment where applicable, with second moment level two reliability analysis wherever feasible. The resulting formulation is a process of suboptimization. By adjustment of the free code parameters the safety index is made close to the target safety index. Safety indices were calculated for 20 selected existing bridges redesigned using calibrated load and performance factors. The scatter of safety indices for redesigned bridges is significantly reduced. It was found that further research is required to provide more information on serviceability limit states such as cracking in prestressed concrete bridges and permanent deformations of steel girders.