| Summary: | 碩士 === 國立臺灣大學 === 生物環境系統工程學研究所 === 93 === In recent years, people pay more attention to our ecological environment. The traditional check dam has been replaced by penetrative comb typed dam in the prevention of debris flow for the balance between ecosystem and safety. The problem is that the current available researches on comb typed dam design are all based on its shape. They do not describe the properties of debris flow passing the comb typed dam. Therefore, in our research, we simulate the properties of debris flow passing the comb typed dam and implement the dimensional analysis to find out the relationships between related factors and the impoundment capability. A mathematical model of the impoundment capability is then derived from the above discussion together with the regression analysis based on available literatures as the following:
P＝2.26•(C)0.13•(b/Dm)-0.93•(Σb/B)-0.45•(q/√(gD503))-0.22•σ0.25
R2=0.77
Here, P = block rate (blocked debris/total debris); S=gradient；C=debris load per unit volume before the arrival of debris flow; b = comb typed width; D50 = median diameter of debris; B=rive breadth; q=unit discharge of water flow passing the comb typed dam; distribution factor (σ=D84.1/D15.9) ， b/D50＝1.34∼11.97，Σb/B＝0.3∼0.85，σ＝1.2∼5.8
Based on this model and on-site data of river, major factors like comb typed width, density and effective height can be calculated during the design of comb typed dam.
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