河道擴幅角對土石流堆積影響之研究

STUDY ON THE EFFECTS OF THE FLUME DIFFUSION ANGLE ON THE DEPOSITION OF DERRIS-FLOW

江永哲(Yung-Cheh Chiang) ； 黃志彰(Jya-Jang Huang) ； 連惠邦(Hui-Pang Lien) ； 林宏鳴(Hung-Ming Lin) ； 吳政達(Cheng-Da Wu)

《中華水土保持學報》 24卷2期 (1993/11) Pp. 91-99

https://doi.org/10.29417/JCSWC.199311_24(2).0009

摘要

本文以動量方程式爲基礎，利用混合流層理論，在土石流堆積過程中，加入一摩阻力因子，進而推導出一土石流堆積理論式，同時利用影響土石流堆積之各項因子，以無因次分析求得其相互間之方程式。在室內渠槽試驗方面，採用一種粒徑級配之試料，三種不同之坡度，在堆積部則以三種不同糙度，四種擴幅角在三種不同之土石流體積濃度下進行試驗，試驗結果得知吾人所推導的理論式，具有相當的可行性，而各項因子所形成之堆積經驗式，各參數間亦具有高度相關性。在本試驗中，首次提出臨界擴幅角的觀念，認爲超過該角度後，此時土石流在擴幅面上之分離點將不再受影響，經試驗結果證明有此一現象，而擴幅角本身有分離土石流之效果，亦與試驗相符合。

關鍵字

土石流 ； 擴幅角 ； 堆積

並列摘要

Basing on momentum equation, this paper used mixed-layer theory to deduct a theory formula of deposition of debris flow which a friction drag factor was added. At the same time, a equation was found through dimensionless analysis from all the factors that affect the deposit of debris flow. The laboratory experiments were proceeded under one kind of gravels distribution, three slopes. three roughness of deposit area, four diffusion angles. and three volume concentrations of debris flow. From the results of the experiments. not only the theory formula had shown its availability but also the high correlations among the factors were found from the experical formula of deposition. The concept of critical diffusion angle was the first time to be introduced and proven in the experiments. From that, we also know that the diffusion angle has the separation effect on the debris flow.

並列關鍵字

Debris Flow ； Diffusion Angle ； Deposition