調節式防砂壩之囚砂效率探討

Study on the Sediment Trapping Efficiency of Adjustable Check Dam

邱士恩(Shih-En Chiu)

指導教授 ： 許中立

國立屏東科技大學/工學院/水土保持系所/碩士(2016年)

摘要

本研究利用二維數值模式CCHE-2D模擬知本溪上游處加入壩體後之水理、輸砂模擬及人工渠道試驗，於渠道模擬中放置封閉式防砂壩、梳子壩、鋼管壩及梳子結合鋼管之壩體，經重現期距50、100年之含砂流量模擬後，探討各防砂壩的囚砂效果，並利用鋼管可拆除的特性，拆除後壩體的土砂流出情形，以瞭解「調節式防砂壩」之功效，探討調節後的河床變化。
二維數值模擬結果顯示，加入封閉式防砂壩，土砂被攔蓄於壩體的上游，因此壩體上游的河床糙度及水位會因此升高；梳子壩為開口式壩體，無法攔阻大粒徑之礫石，但建築壩體後影響了河床之坡度，下游因為有隘口造成束縮，大粒徑之礫石會在此停留，造成河床糙度增加，土砂也在此悽置。
人工渠道試驗結果顯示，封閉式防砂壩的囚砂率為最高，由於封閉式防砂壩為非透過性壩，會將所有土砂所攔阻於壩體的上游處，因此其囚砂率較高。梳子壩加鋼管壩之壩體之囚砂率較無封閉式防砂壩佳，但囚砂率優於其他開口式壩，梳子壩加鋼管與鋼管壩相比，確實囚砂率有上升，主要原因是因為梳子壩有封閉式結構，能夠攔阻土砂之面積較多，因此囚砂率較高。

關鍵字

防砂壩 ； 囚砂 ； 攔阻泥沙 ； 鋼管

並列摘要

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.

並列關鍵字

Check Dam ； Sediment Trapping ； Arresting Sediment ； Steel Pipe

參考文獻

5.李岱玲，2011，CCHE2D模式應用於蜿蜒複式河槽變遷之研究，碩士論文，國立交通大學，土木工程學系，新竹。

1.王圍穩，2009，壩體移除對河床變化之試驗研究與鋼管壩之鋼構安定分析，碩士論文，國立中興大學，水土保持學系，台中。

15.趙益群，2006，孔隙型防砂壩對細顆粒泥砂囚砂效果之研究，碩士論文，國立中興大學，水土保持學系，臺中。

11.陳世鎮，2011，頭前溪河口沖淤問題分析及對策研究，碩士論文，國立中興大學，水土保持學系，台中。

6.林欣怡，2008，防砂壩移除對河床變遷影響之研究─以巴陵壩為例，碩士論文，國立台灣大學，土木工程學系，臺北。