Bridge Classes for the Regional Risk Assessment of Box-Girder Bridges in California: Improving HAZUS Models

Regional risk assessment of bridge classes necessitates the grouping of bridge classes. Although HAZUS categorizes bridges and is compatible with the National Bridge Inventory, it suffers many drawbacks such as grouping based on traditional subjective approaches, doesn’t adequately consider the difference in bridge performance, failure in explicitly addressing the evolution in seismic design philosophy and the effect of number of spans, to name a few. This paper uses a performance based grouping technique called analysis of variance to improve the HAZUS grouping of bridge classes. The proposed approach is able to identify the bridge parameters which have a significant influence on the seismic demand and the fragility curves. The paper improves the HAZUS grouping of box-girder bridges in California accounting the effect of various design attributes such as abutment-type, number of spans, number of frames, span continuity, design philosophy, and pier type.