Numerical Investigation Into Effect of Canyon Terrain Boundaries on the Seismic Response of Deep-Water Bridge Piers

Abstract

Bridge piers in deep reservoirs with canyon terrain boundaries are subject to complex hydrodynamic effects during earthquakes. In this study, a framework with added mass is adopted to calculate the effects of canyon terrain boundaries. This approach is demonstrated to be effective and accurate after the results from the fluid–structure interaction model and the model with the added mass method are compared. Then, the impacts of canyon terrain boundaries on the seismic response of bridge piers in deep reservoirs are numerically investigated. The effects of key parameters such as the pier-to-boundary distance, terrain slope angle, and water depth are also thoroughly studied. The results indicate that the canyon tunnel boundaries have larger influence zones along the height of the bridge pier when it has a larger terrain slope angle and a lower water depth. Although the dynamic characteristics did not change much after the specific topographic conditions were considered, the dynamic response greatly increased in terms of base forces and deformation. Moreover, this study underscores the critical importance of canyon terrain boundary conditions in the seismic design of bridges in mountainous reservoir regions.