Framework of Practical Performance Evaluation and Concept of Interface Design for Bridge Deck-Wave Interaction

摘要

The connection, or interface, between the bridge superstructure and substructure is a key component in a bridge system for resisting hurricane-induced storm surges and wave forces. The performance of the connection can influence the survivability of the bridge superstructure in hurricane events and the strategic design of the entire bridge structure. This paper presents a framework for a practical performance evaluation that incorporates a proposed structural capacity model and highlights the concept of interface design for coastal bridges vulnerable to wave impacts. First, prior to the application of the framework, scenarios with maximum wave forces were computationally investigated through a parametric study in which different water depths and submersion coefficients, representing the rising water level of the storm surge as a hurricane approaches and makes landfall on the coast, were considered. A consensus on the scenario with the maximum vertical force was reached through a typical laboratory study. Then, on the basis of the successful verification with an experimental study on a clip-bolt-type connection, or anchorage, using the FEM, a structural capacity model (i.e., the ultimate resistance envelope) for the clip-bolt-connection model was proposed. The resistance envelope can be conveniently used to evaluate the vulnerability of existing coastal low-lying bridges. Meanwhile, the critical elevation concept, reported in the literature and defined as a means to determine whether or not a bridge deck could be displaced at a certain wave-crest elevation, was clarified in a more rational way. Furthermore, the concept of the interface design was emphasized because it aims to reduce the distributed wave loads and improve the resistance envelope via typical retrofitting options at the susceptible connections. This study provides practical guidance for the connection design for bridge deck-wave interactions by suggesting the use of a proposed structural capacity model for a three-step framework.