Vulnerability of coastal bridges under extreme hurricane conditions

Abstract

 Accurate methodologies to quantify the vulnerability and resiliency of coastal infrastructure to wave-induced forces are crucial to sound risk management in coastal regions where hurricane hazard is high. This paper describes a high-resolution coupled Eulerian-Lagrangian (CEL) finite element model to evaluate the vulnerability of coastal bridges to wave-induced forces during large storms. The modeling technique was calibrated and shown to be in good agreement with experimental results from a reduced-scale bridge structure tested at the O.H. Hinsdale Wave Research Laboratory at Oregon State University. The high-resolution bridge model was used to simulate the response of common types of bridge structures to hydrodynamic loads under hurricane conditions (i.e. surge height, wave height, and frequency) expected in the Texas-Louisiana coast. Results show that superstructure-substructure connection demands for bridges under wave impact loading are sensitive to the flexibility of the substructure, which has historically been modeled as rigid in flume experiments and computer simulations used to develop current design provisions.