Author(s): Marko Shao Hua Hsu, Yu-Huan Chang, Chong Yu Sun, Pi Fang Hung
Linked Author(s): Shaohua Marko Hsu
Keywords: Gravel-bed River, scouring processes, field monitoring, wireless tracer, scour block pile
Abstract: Under the influence of climate change, the intensity and frequency of rainfall events are increasing significantly. During typhoon seasons, warning announcement of the safety of a bridge cannot rely on numerical simulation in advance; the authority counts on the real-time monitoring of bridge scouring to making decision for bridge closure. In recent years, in order to secure the safety of a bridge across the river, the units in-charge will usually arrange energy-dissipating blocks around bridge piers or structures to form a simple groundsill protection. The characteristics of aggradation and degradation of Taiwan rivers are, however, more dramatic than continental rivers with mild slopes. These features increase the local scouring behind the protection works and cause structures damage starting from exposure of their foundations. Because the protection works fail, it will lead to the breakage of river dikes, bridge piers, and embankments, hence endangering people's lives and properties. Real-time monitoring on a river-bed fluctuation during a flood event is still difficult. One approach is by scour blocks, which can only obtain the maximum scour depth after the events; but in reality, the scour depth varies real-time with the discharge hydrograph still not available. In this study, a real-time monitoring has been conducted successfully during year 2015 to 2016, by employing the wireless tracer with scour blocks, and collecting the scouring data of gravel bed river during flood events. By real-time transfer of the data, we can monitor the progress of scouring hole with flow hydrograph behind the protection works. Furthermore, by receiving the signal in real-time can help the authorities in making decision on bridge closure more accurately
Year: 2017