Model Research of Flushing Efficiency for Amuping Desilting Tunnel of Shihmen Reservoir

• Main Authors: Po-Han Wu, 吳柏翰
• Other Authors: Hsun-Chuan Chan
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/41675784724420191104

碩士 === 國立中興大學 === 水土保持學系所 === 103 === Shimen Reservoir is a multi-objective reservoir, but it was original designed without any silt-sluicing facility in 1963. Through years of operation the reservoir has experienced severe siltation. In order to maintain the capability and stability of water supply, it has become imperative issue that how to reduce sediments and extend the life of the reservoir. Water Resources Agency, Ministry of Economic Affairs was currently planned to build desilting tunnel in midstream Amuping of the reservoir. Usually silt in the flushing pool is pumped by sand suction dredger from the reservoir and is flushed to downstream Tahan River to supply the sand source during heavy rain or typhoon period. This research tested flushing efficiency of " Amuping desilting Tunnel of Shihmen reservoir " by hydraulic model. We adapted 1:40 scale model test by the ability of water supply, sand volume, space of the test site and other factors. The sediment flush ratio of case 4 is the best after testing four cases. It can be up to 97.55%. In order to explore the flushing efficiency under diffent degree of compaction caused by different silt piling time, we kept doing two test that change the silt piling time (extended from seven days to 14 days) under case 4 conditions. The test results show that sediment flush ratio has decreased to 84.62% when dry unit weight increased caused by increased silt piling time. In order to achieve the same sediment flush ratio, it required much more flushing time from 11.07 hours extended to 31.62 hours and water consumption is increased from 23.91 million m3 to 68.30 million m3. It worth the decision unit to evaluate the cost.