地表水及地下水對土石流破壞型態之影響

The Effects of Surface Runoff and Ground Water on the Occurrence of Debris Flow

林美聆(Meei-Ling Lin) ； 王幼行(Yu-Shin Wang)

《地工技術》 74期 (1999/08) Pp. 29-38

https://doi.org/10.30140/SG.199908.0002

摘要

本文以水槽物理模型試驗，探求不同之供水模式對土石流發生之影響。供水模式一由水槽頂端供水，以印證高橋（Takahashi）的理論以逕流所增加之剪切力引起土體推移滑動。另一由水槽底部供水，即印證地下水由土體底部破碎之岩盤湧升，導致孔隙水壓快速上升，誘發土石流產生的現象。試驗結果顯示，頂部供水時，土體破壞的主因為逕流的沖刷、侵蝕。而由底部供水時，產生較大規模的破壞，破壞的主因為孔隙水壓上升，有效應力降低所致。而不同供水型態之破壞特徵，可提供為驗證現地土石流破壞型態之參考依據。

關鍵字

土石流 ； 水流模式 ； 破壞型態

並列摘要

The objective of this paper is to explore the effects of different modes of water supply on the occurrence of debris flow. The physical model was used with water supplied from the upstream tank to simulate surface runoff, and with water supplied from hoses in the base to simulate the upwelling of ground water. It is found that the debris flow caused by surface runoff has a smaller scale and behaves more like erosion process. The debris flow caused by upwelling of ground water has massive movement and is induced by lowering of effective stress. The characteristics of the two different modes can be used to verify the field conditions with enough field evidences.

並列關鍵字

debris flow ； water supply mode ； type of failure