PHYSICAL MODELING OF HYDRAULIC DESILTATION IN TAPU RESERVOIR
摘要
A movable bed physical model was constructed to investigate hydraulic desiltation by flushing and lateral erosion in the Tapu reservoir, Taiwan. The model scaling is based on the requirement for dynamic similarity of cohesive sediment deposit initiation in flushing processes. For model scaling, flume experiments investigating the initiation of cohesive sediment deposits were carried out to establish the relationship between critical shear stress of the flow and dry density of the deposit. Experiments in the physical model were then performed to measure the variations of the reservoir water level, the outlet discharge and the outflow sediment discharge. The processes of emptying and flushing were observed and analyzed in the main flushing channel. One of the experiments was conducted to simulate the on-site flushing operations on June 11, 1997. The results showed that the total 0cumulative flushed sediment volume by physical modeling was close to that by numerical simulation. To deal with the fioodplain deposits, experiments of lateral erosion as an auxiliary method were also conducted in the physical model to investigate the effectiveness and applicability for the0 Tapu reservoir.