• 作者： 游繁結
• 作者服務機構： 國立中興大學水土保持學系
• 中文摘要： 近年來，台灣山坡地土砂災害有逐年增加之趨勢，其中以土石流災害因其規模大且破壞力強，而被逐漸重視，為掌握土石流破壞力之特性，本文擬藉水槽試驗以瞭解土石流衝擊力之機制。 依流體動壓力之理論，影響土石流衝擊力之因子主要為流體之密度與流速，因之，本研究即針對此二因子探其對土石流流動所產生衝擊力之問題，而由水槽試驗結果，獲致如下之結論與建議，即： 1．土石流先端部之流動體積濃度（Cd）受坡度（θ）與土體孔隙率（η）之影響，而可由下式推估之： Cd=0.0718+0.9161 tanθ+0.1031(1/η) 2．土石流先端部之流動密度可由下式推求得之： （方程式無法摘錄） 3．土石流實測之流速與理論計算所得者，相當近似，惟應用時為安全估算起見，可採用理論值之2倍。 4．土石流之衝擊力可以理論流速之2倍及土砂粒子之密度依下式推估之，　　　（方程式無法摘錄） 5．建議選擇適當之地點設置觀測儀器，以實際瞭解現地土石流流動之狀況。
• 英文摘要： The oeeuranee of sloPeland disasters in Taiwan has signifieantly inereased reeently. One of themajor tyPes of disasters is induced by debris-flow with large seale and strong destruetion. This PaPer isbased on flume experiments to quantify the impaet foree of debris-flow. Aeeording to the theory of the dynamie pressure of a fluid, the faetors affeeting the impaet forceof debris-flow are the density and veloeity of the fluid. The objective of this study is, therefore, to assessthe role of the impact force and diseuss the factors of density and veloeity when the. debris-flow occurs· The conelusions and suggestions are as follows 1. The volumetrie concentration Cd at the front of the debris-flow is affected by the slope anlge(θ), and the porosity (η) of the deposit layer. It ean be expressed by the equation Cd=0.0718+0.9161 tanθ+0.1031(1/η) 2. The flowing density at the front of a debris-flow can be expressed by the equation (方程式無法摘錄) 3. The measured average veloeity of the front of the debris-flow agreed well with those valuesealculated from the theoretieal equation whieh was derived previously. However, for a conservativeestimate, we could take 2 times the theoretical velocity value for use. 4. Using 2 times the theoretieal veloeity and substituting the particle density of deposition for theflowing density of debris-flow, the equation of dynamie pressure ean be modified as in the followingequation to estimate the impact force of debris-flow: (方程式無法摘錄) 5. To understand the real action of debris-flow on a field, it is suggested that proper monintoringequipments be established for observing the movement of debris-flow.
• 中文關鍵字： debris-flow; flow density; volumetric voncentration; dynamic presure; impact force
• 英文關鍵字： --