Performance of AASHTO girder bridges under blast loading

AASHTO has specified probability-based design methodology and load factors for designing bridge piers against ship impact and vehicular collision. Currently, no specific AASHTO design guideline exists for bridges against blast loading. Structural engineering methods to protect infrastructure systems from terrorist attacks are required. This study investigated the most common types of concrete bridges on the interstate highways. A 2-span 2-lane bridge with Type III AASHTO girders was used for modeling. AASHTO Load and Resistance Factor Design methods were used for the model bridge design. The girders, pier caps and columns loading were analyzed for probable blast loading. The model bridge failed under the probable blast loads applied over and underneath the bridge. The research findings show that typical AASHTO girder bridges are unable to resist probable blast loads.