Time-Dependent Local Scour of Circular Bridge Pier

Bridge pier scour is an important engineering concern because of the role that it can play on the safety of the bridge. Due to the importance of this topic, many researchers have worked on this critical subject but most have focused their studies on clear-water scour condition and estimation of equilibrium scour depth. The current bridge foundation design is also based on equilibrium scour depth. More recent studies show that bridge foundation design based on equilibrium scour depth usually leads to more conservative design because peak flood periods are often too short to reach equilibrium conditions. Additionally, in a flood event, live-bed scour condition is more common than clear-water scour condition. The overall focus of this research is the temporal estimation of local scour depth of a circular bridge pier. In this study, a time-dependent power-exponential model and a time-dependent semianalytical model respectively are presented for clear-water scour depth and live-bed scour depth of a circular bridge pier. Moreover, real-time bridge scour monitoring method and applications of the models are described. A knowledge of the structure, flow and sediment is required as input to the models. Models are tested and verified with experimental data from the literature. These models can be used as novel and powerful design and monitoring tools for more realistic bridge foundation design and better bridge management strategies