頁籤選單縮合
題名 | 細料流失現象對引發山谷型與邊坡型土石流之影響=Influence of Fines Washed-Away on Initiation of Valley and Slope Type Debris Flows |
---|---|
作者 | 何敏龍; 陳榮河; Ho, Min-lung; Chen, Rong-her; |
期刊 | 中國土木水利工程學刊 |
出版日期 | 19970300 |
卷期 | 9:1 1997.03[民86.03] |
頁次 | 頁1-15 |
分類號 | 434.273 |
語文 | chi |
關鍵詞 | 土石流; 土石流初始發生; 母質材料; Debris flows; Initiation of debris flows; Matrix material; |
中文摘要 | 本文探討堆積層細料流失對山谷型與邊坡型土石流發生之影響。本研究先依現場調查結果進行土體堆積結構型態之判別,決定細料流失現象之模擬方式,在不考慮孔隙水壓之變化條件下而採用室內大型直接剪力試驗,探討該現象對土體剪力強度、變形性之改變,以及對土石流初始發生之影響。試驗結果顯示,土體之凝聚力大小與細料含量多寡成正比,內摩擦角則隨細料流失量之增加而呈現先降後升的現象,即存在一摩擦角最小值;土體受剪時之變形性在級配、礫石種類相同狀況下,受初始孔隙比、所受正應力大小與含水量等因素影響。據此分析銅門村土石流之臨界發生,發現堆積層之穩定性因細料持續地流失,會漸降至一個臨界點,因此,當土體強度在適當環境因素如地形、水文條件下即能引發土石流。 |
英文摘要 | The phenomenon of fines washed-away from the deposits and its influence on the initiation of valley and slope type debris flows are studied. In-situ investigation is performed to understand the structure of deposits for defermining the experimental model of the fines washed-away. Largescale direct shear tests are conducted to simulate the phenomenon and its effect on the material properties. The material properties are used with the criterion of debris flows suggested by Takahashi to determine the relationship between fine contents and the initiation of debris flows. The results of large-scale direct shear tests reveal that the cohesion of the deposits is in proportion to the fine content. The angle of internal friction will drop to a minimum value then increase as fine content reduces continously. Takahashi's equation is adopted in analyzing the stability of the deposits in Tungmen Village. The factor of safety versus concentration curves exhibit a concave characteristics. When enough fines are washed-away, the factor of safety will decrease to a critical value, then debris flows will be induced under such topographic and hydraulic conditions. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。