Author(s): Changhai Han, Yu Yang, Yanfu Li, Gaowen Tan
Linked Author(s): Changhai Han
Keywords: Riverbed incision, hydraulic structure, two-stage energy dissipater, hydraulic experiment, limited riverbed incision depth
Abstract: Riverbed incision at the downstream of the dam would induce water level fall and water fluctuation. As a result, the original energy dissipater could not be able to dissipate water energy completely and be liable to be destroyed. The main feasible countermeasure is building a lower stilling basin next to the original one. Xiaobudong rubber dam is the world's longest rubber dam project with length of 1135m, which two stage energy dissipation structure is used. Due to excessive sand mining, the riverbed has been sharply incised, and the energy dissipation structure have been destructed. The structure has been reinforced many times, but equally destructed many times. After a heavy flood season, the energy dissipation structure between the first stilling basin and the second still basin have been destroyed along the whole dam, which brought huge economic losses and threat to the rubber dam safety. In this study, based on hydraulic experiment and field investigation, the failure of the energy dissipater of Xiaobudong dam is analyzed. The connection section between the first and second stilling basins has been redesigned, as a result, stable hydraulic jump is formed in the first and also in the second stilling basin. Besides, the limit depth of riverbed incision is also studied. After reinforcement measures are actually implemented, the energy dissipater of the dam is adapt to dissipate the water power, and the energy dissipation structure suffers no damage again. The ideas and measures of the reinforcement in this study can provide a reference for other energy dissipaters facing the similar threat caused by riverbed incision
Year: 2017