以渠槽實驗探究防砂壩開口寬度設計對上游淤砂之影響

Small-Scale Flume Experiment to Investigate the Influence of Check Dam Opening on Upstream Deposition

邱元鴻(Yuan-Hung Chiu) ； 洪啟耀(Chi-Yao Hung)

《中華水土保持學報》 52卷4期 (2021/12) Pp. 185-195

https://doi.org/10.29417/JCSWC.202112_52(4).0001

摘要

防砂壩的設計中防砂量之估算與上游淤砂坡度、輸砂坡度及壩體寬度開口大小相關，為探究開口寬度對淤砂之影響，本研究以渠槽試驗在固定流量、供砂量情況下調整渠底坡度與壩體開口大小，透過新型影像量測方法，量測淤砂坡度、輸砂層坡度和輸砂層厚度之變化。結果呈現壩體開口大小將影響淤砂坡度和輸砂層坡度，且隨著渠底坡度的變陡，輸砂層坡度也會變陡，而淤砂坡度達最大值後即趨緩。透過無因次分析，可初步得出淤砂影響之經驗公式。

關鍵字

開口式防砂壩 ； 輸砂層運動坡度 ； 粒子影像分析 ； 渠槽實驗

並列摘要

Check dam effectiveness is related to the sediment deposition slope upstream, sediment transport layer slope, and the width of the check dam opening. In this study, small-scale channel experiments were conducted to study the variation in the deposit slope behind the check dam, the sediment transport layer's slope, and the sediment transport layer's thickness with different degrees of check dam openness and river slope conditions. A new laser cross-sectional measurement was developed to avoid the boundary effect and measure the sediment transport layer. The results suggest that the deposit slope and transport layer are significantly affected by the check dam's openness. Furthermore, they increase with the river bed slope. In accordance with the experimental results, dimensionless analysis was applied, and a preliminary prediction formula was developed for determining check dam effectiveness.

並列關鍵字

Silt Dam ； Dynamic Sediment Transport Layer ； Particle Tracking Velocimetry ； Small-Scale Flume Experiments