溪床堆積土體崩壞模式及其土石流化之研究

Failure Model of Sediment Layer and Its Transformation into Debris Flow in Channel Bed

連惠邦(Hui-Pang Lien) ； 趙世照(Shih-Chao Chao)

《中華水土保持學報》 27卷3期 (1996/09) Pp. 175-183

https://doi.org/10.29417/JCSWC.199609_27(3).0001

摘要

本研究主要在探討溪床堆積土體崩壞後之土石流化問題，並分別建立了土體崩壞之理論模式，以及土體崩壞後形成土石流之限制條件。在土體崩壞模式中，由一無限邊坡厚度均勻之堆積土體出發，考慮孔隙水滲流方向、固體泥砂顆粒間粘聚力、孔隙水高度比（m）及地表逕流高度比（n）等不同條件，建立溪床堆積土體崩壞之通用模式。同時，引入土石流最小泥砂體積濃度觀念，導出土體崩壞後土石流化之溪床臨界坡度方程式。經與其他研究者試驗資料驗證均可達到良好之效果，顯示土體崩壞理論及其土石流化之限制條件，可有效地模擬溪床堆積土體崩壞之土石流化過程。

關鍵字

土石流 ； 推移力 ； 滲流力 ； 阻抗力 ； 臨界坡度

並列摘要

This study concerns the failure model of sediment layer and the criterion of occurrence of debris flow produced from a failured sediment layer in a channel bed. First, a failure model for an infinitely long, uniform depth of sediment layer is developed basing on the parameters; such as seepage direction of interstitial fluid, cohesive strength of sediments, the ratio of interstitial fluid thickness to sediment layer thickness (m) and the ratio of surface water flow depth to sediment layer thickness (n). Second, the critical channel slope for the occurrence of debris flow transformed frim a failured sediment layer is determined basing on the concept of minimum concentration of solid particle in debris flow. The result of the formulation of failure model and its transformation into debris flow is shown to be in excellent agreement with the experimental data obtained by previous investigators.

並列關鍵字

Debris Flow ； Tractive Force ； Seepage Force ； Resistance Force ； Critical Slope