Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/33837
標題: 不同粒徑組成土石流流動特性之研究
作者: 賴建信
G.S.Lai
關鍵字: debris flow;土石流;free pore ratio;自由孔隙比
出版社: 水土保持研究所
摘要: 
本文即從流動阻力之觀點,配合室內渠槽試驗,在不同流量、坡度下針對
不同土砂粒徑組成之溪床堆積土砂受流水剪切力作用所形成之土石流流動
性狀進行分析與探討。試驗研究結果顯示,不同粒徑組成之土石流其運動
特性也有所差異,當細粒土砂含量達40% 時,即不易形成土石流。而土石
粒間之碰撞效應為土石流段波形成之主因,細粒材料配比較多之土石流流
動受到較低之阻抗,流動性較佳,土石流之形成不易;反之,缺乏細粒材
料拌合之土石流其碰撞效應高,間歇性之流動較顯著,段波也較高。同時
以自由孔隙比之觀念,可以用來判定土石流之流態,且可以該參數替代紊
流理論之Von Karman常數,以修正土石流平均流速之推估。

This experiment which was simulated with flume experiment in
laboratory, was trying to understand the flowing mechanism of
debris flow with different grain size composition. And the
characteristic of shear stress was theoritically divided into
intergranular collision stress and resistance stress in order
to state the behavior of debris flow. The experiment results
displayed that the flowing character- istics of debris flow
varied with its grain size composition, meanwhile the
intergranular collision effect mainly determined the formation
of surges. And the fluid with more than 40% of fine particles
was difficult to form debris flow due to less resist- ance in
flowing. On the contrary, the debris flow with less fine
particles content would induce more intergranular collision to
form higher surge, and because of higher resistance with the
intergranular collision debris flow would temporarly stop and
than flow down again. By introducing the parameter of free pore
ratio,it could be used to distinguish the flow type which was
debris flow or not, and the flowing velocity of debris flow
could be modified by using this parameter.
URI: http://hdl.handle.net/11455/33837
Appears in Collections:水土保持學系

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