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題 名 | 突擴斷面土石流淤積形態幾何相似特性之研究=Study on the Geometric Similarity of Debris-Flow Deposition in a Sudden Expansion Section |
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作 者 | 謝正倫; 蔡元芳; | 書刊名 | 力學 |
卷 期 | 13:1 1997.03[民86.03] |
頁 次 | 頁11-19 |
分類號 | 434.273 |
關鍵詞 | 突擴斷面; 土石流; 土石流扇狀地; 因次分析; Sudden expansion section; Debris flow; Debris fan; Dimensional analysis; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究利用一系列的室內實驗及因次分析方法,成功的歸納出土石流在突擴斷面 處淤積形態的幾何相似特性。 實驗中土石流係以粒徑 d �t =1.6mm 之均勻細石及水在陡坡 渠道中充份混合後流出形成。由實驗結果顯示,當土石流自渠道進入平坦且寬廣的平臺後會 迅速淤積,並形成所謂之土石流扇狀地( debris fan )。本研究以扇狀地之中心軸長度( Lc )、最大寬度( Bm )及扇頂淤積厚度( Zo )等三個地形量作為特性長度, 針對扇狀 地之縱剖面、橫剖面及平面之形態,進行因次分析。由分析結果可知,土石流扇狀地之無因 次縱剖面及無因次橫剖面在平衡階段皆具有高斯曲線之形狀特性, 而其形狀係數分別為 C �� =0.40、C �h =0.20。至於無因次之平面形態則近似一圓弧。 文中並利用 Takahashi ( 1979,1980 ) [1,2] 之土石流扇狀地實驗結果,以相同之因次分析法進行上述之分析,其 結果與本研究所得幾乎一致。 本文最後並進一步以上述所得之無因次形態函數推導土石流扇狀地之體積得�f =0.23 ( Lc . Bm . Zo ),此結果與實驗量測所得結果十分相近。 |
英文摘要 | The configurations of debris-flow deposition in a sudden expansion section were derived successfully by laboratory experiments and dimensional analysis method. The sediment material used in experiments had a uniform diameter of 1.6mm. A debris flow was created by fully mixing of sediment and water in a steep flume. Experiments showed that once the debris flow entered the flood basin of gentle ground slope, it would spread out, deposit quickly, and form the debris fan. The maximum topographic values of the length ( Lc ),width ( Bm ) and depth ( Zo ) of a debris fan were used as characteristic length to analyze the dimensionally longitudinal, transverse profiles and shape of a debris fan. The results of analysis showed that the non-dimensional profiles of the debris fan in a stable stage could be decribed by Gaussian curves in both the longitudinal and the transverse directions with coefficients C �� around 0.40 and C �h around 0.20. The shape of the fringe of debris fan is similar to a half of a circular. The shape of the fringe of debris fan is similar to a half of a circular. The present experimental results as well as Takahashi's ( 1979 ,1980 ) [1,2] were adopted to analyze the characteristics of debris fan. Finally, according to the dimensional function of the configuration of debris-flow fan mentioned above, the total volume could be approximated by �f = 0.23 ( Lc . Bm . Zo ).This calculated value is much the same with the measured total volume of debris fan. |
本系統中英文摘要資訊取自各篇刊載內容。