土石流流動機構之研究

Study on the Mechanism of Debris Flow

連惠邦(Hui-Pang Lien) ； 蘇重光(Chong-Guang Su) ； 江永哲(Yung-Cheh Chiang)

《中華水土保持學報》 25卷3期 (1994/09) Pp. 151-160

https://doi.org/10.29417/JCSWC.199409_25(3).0004

摘要

本研究係利用摩擦阻力、離散剪應力與剪應力間的平衡原理來描述土石流運動，進而推導得到土石流縱剖面的速度分布方程式。經與實測資料驗證，結果甚爲理想。本模式中引入「底部滑動流速」的觀念，可全面地模擬土石流縱剖面上三種不同類型的速度分布，解決一般土石流運動模式只能模擬單一類型速度分布的限制。同時，「底部滑動流速」觀念可作爲決定摩擦阻力係數之依據。由分析結果顯示，土石流具底部滑動流速時，其摩擦阻力係數爲零（摩擦阻力消失），否則摩擦阻力係數等於1。此條件大大提高了本模式的實用性。

關鍵字

土石流 ； 摩擦阻力 ； 離散剪應力 ； 底部滑動流速

並列摘要

In this study the equilibrium among friction force, dispersive shear stress and shear stress is used to construe the mechanism of debris flow and its velocity distribution. The derived equation of velocity distribution is checked with experimental data and good results obtained. Into the proposed model＜ the concept of bottom velocity is introduced and all the three types of velocity distributions are so well described by the single model that it is no more necessary to have one equation of velocity profile for each type of distribution. In the meanwhile, the bottom velocity can be used to determine the resistance coefficient. According to the results of analysis, when the debris flow involves the bottom velocity, the resistance coefficient is zero. Otherwise, the resistance coefficient is unity. These conditions greatly facilitate the application of the model.

並列關鍵字

Debris Flow ； Fiction Force ； Dispersive Shear Force ； Bottom Velocity