土石流堆積性狀之初步探討

PRELIMINARY STUDY ON THE CHARACTERISTICS OF DEPOSITION OF DEBRIS FLOW

江永哲(Yung-Cheh Chiang) ； 林裕益(Yuh-Yih Lin)

《中華水土保持學報》 18卷2期 (1987/11) Pp. 15-27

https://doi.org/10.29417/JCSWC.198711_18(2).0002

摘要

本研究旨在探討土石流發生後之各種堆積特性，業經野外現場調査與室內渠槽試驗之結果，獲致如下結論：（1）大致而言，池谷浩所提出之土石流堆積長度經驗式：logL = 0.42 log（V × tan^α）+0.935式中，L爲堆積長度（m），V爲土石流流出量（m^3），α爲流下部之平均坡度（°）。因受地形條件影響，上式所推估堆積長度（L）之計算値，較野外現場調査之實測值爲大。（2）堆積物含水率相當，下坡角（S_d）相同條件下，其流下部坡降（S_u）愈緩，則堆積長度愈短，堆積面積亦愈小。（3）於流下部坡降27°，堆積部坡降0°時，其含石率（或土石比例）亦相似之條件下，含水率與堆積面積對數成線性關係。（4）於含水率相當及坡降條件相同時，堆積長度或面積隨含石率增大，而有遞減之勢。（5）堆積長度對數與堆積寬度成線性關係。（6）堆積部之分散角與形狀比成線性關係。

關鍵字

土石流 ； 土石比例 ； 堆積長 ； 分散角 ； 含水率

並列摘要

The object of this paper was to study the properties of the deposit shapes formed by debris flow. When the field investigation and the laboratory experiments performed, the results were obtained as follows: 1. Generally speaking, the empirical formula of the length of deposit submitted by Ikeya is log L=0.42 log (V × tanα) +0.935 where L is the length of deposit (m), Vis the volume of deposit (m^3), a is the mean slope of flow area (°). Due to the different geomorphological condition, the length of deposit estimated by the empirical formula is larger than it of actual investigation. 2. When the water content of deposit and the gradient of deposit area keep constant. The smaller the gradient of flow area is the shorter the length of deposit and the smaller the area the deposit will be. 3. When the gradient of flow area is 27° and the gradient of deposit area is and the ratio of soil to gravel keep constant, there's the linear correlation between the water content and the logarithm of the area of deposit. 4. When the water content and the gradient keep constant, the length and area of deposit decreased with the increasing ratio of soil to gravel 5. There's the linear correlation between the logarithm of the length of deposit and the width of deposit. 6. There's the linear correlation between the angle of dispersion of the deposit area and the ratio of deposit width to length.

並列關鍵字

Debris flow ； Ratio of soil to gravel ； Deposit length ； Angle of dispersion ； Water content