DYNAMIC INTERNAL FRICTION ANGLES OF IDEALIZED DEBRIS FLOWS

理想化土石流之動內摩擦角

詹錢登(Chyan-Deng Jan)

《中華水土保持學報》 24卷1期 (1993/05) Pp. 29-36

https://doi.org/10.29417/JCSWC.199305_24(1).0004

摘要

Dynamic internal friction angles of idealized debris flows and the angles of repose of idealized mixtures of debris were studied through laboratory experiments. A mixture of uniform glass spheres was treated as an idealized mixture of debris. A flow of the mixture of glass spheres, established in a ring-shear type debris flow apparatus, was used to simulate an idealized bebris flow. Experiments with both 5 mm dry and water-saturated glass spheres were conducted using the ring-shear apparatus to study the dynamic internal friction angles. The friction angles were found to be 13.0 and 16.1 degrees respectively, for dry and water-saturated tests. Experiments with 1, 2, 3, 5 and 14 mm dry glass spheres, using a rectangular container and a rectangular flume, indicate that the corresponding angles of repose are 25.9, 24.2, 23.7, 22.0 and 17.1 degrees, respectively. The angle of repose decreases with increase in the size of glass spheres. Experimental .results show that the dynamic internal friction angle seems to be independent of the bulk shear rate and normal load acting on the glass spheres, and smaller than its corresponding angle of repose.

關鍵字

Debris Flow ； Friction Angle ； Angle of Repose

並列摘要

均匀大小玻璃珠之混合體常被視爲理想化之土石混合體。本研究以實驗方法來研究此理想化土石混合體之動內摩擦角及其安息角。以環狀剪力式土石流實驗機內所形成之5毫米玻璃珠混合體之流動來模擬土石流之流動，並研究其動內摩擦角。實驗結果顯示5毫米玻璃珠和空氣之混合體及5毫米玻璃珠和水之飽和混合體之動內摩擦角分別爲13.0及16.1度。以矩形渠槽研究均匀大小玻璃珠混合體之安息角。實驗結果顯示1、2、3、5及14毫米玻璃珠和空氣混合體之安息角分別爲25.9、24.2、23.7、22.0及17.1度。玻璃珠和空氣混合體之安息角隨玻璃珠直徑之增加而減小。在本實驗範圍內理想化土石混合體之動內摩擦角和平均剪應變率及垂直應力間沒有顯著之關係，而且比其安息角小。

並列關鍵字

土石流 ； 摩擦角 ； 安息角