Study on the Sediment Trapping Efficiency of Adjustable Check Dam

• Main Authors: Chiu, Shih-En, 邱士恩
• Other Authors: Hsu, Chung-Li
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/68058070196053166205

碩士 === 國立屏東科技大學 === 水土保持系所 === 104 === The research utilizes 2D numerical model CCHE-2D to simulate hydrology, sand transporting and artificial channel test of upstream added with dam body in Zhiben River Upstream,and study performed channel tests to simulate closed CDs, SDs, steel pipe dams (SPDs), and steel pipe plus slit dam (SPSDs) 50-year 100-year floods. Results were then analyzed to determine the sediment trapping (ST) effects of various CDs, the effects of “adjustable CDs,” and the changes of moderated riverbeds. The 2D numerical simulation structure shows that soil and sand are retained in upstream of the check dam after sand prevention dam is added, therefore, roughness and water level in upstream of the check dam will rise. Slit-type sabo dam is an open check dam, which cannot block gravel of big grain size, but the slope of riverbed is influenced by the check dam, and the downstream shrinks due to sally port where gravel of big grain size stops, causing increase of roughness of riverbed and retention of soil and sand. Test result of artificial channel shows that trap efficiency of a sealed sand prevention dam is high. The sealed sand prevention dam is a non-pervious dam capable of blocking all soil and sand in upstream, thus its trap efficiency is high. Trap efficiency of the check dam of slit-type sabo dam and steel-pile dam is higher than that of sealed sand prevention dam, but superior to that of other opening check dams. Compared with steel-pipe dam, the trap efficiency of slit-type sabo dam steel pipes is higher mainly because the slit-type sabo dam has sealed structure, which can block more soil and sand.