Risk-Based Assessment of Texas Bridges to Natural and Induced Seismic Hazards

The primary objective of this paper is to study the effects of natural and induced seismic hazards on Texas bridges. Predicted structural damage forms the primary performance metric for this study. The motivation for this research stems from the significant increase in the number of earthquakes greater than magnitude 3.0 in Texas over the past five years. Texas is historically known as a non-seismic region; therefore, this significant increase in seismicity raises concerns over the safety of infrastructure designed with little to no consideration of seismic demands. The bridge population is characterized by different classes, and for each class, computationally efficient nonlinear models are implemented for simulating damage intensity in non-seismically detailed bridge components. The damage level is evaluated based on deformations of bridge components, namely bridge bearings in this paper, and fragility functions representing the probability of exceeding each damage state for various bridge classes are generated. The results show that although it is not likely to have full damage of bearing components after the earthquake, it is more likely to have slight and moderate. This information will be used to inform post-earthquake inspection plans and identify the most vulnerable bridge types in terms of bearing fragility.