非飽和堆積層土石流發生之臨界角度與含水量之關係研究

STUDY ON RELATIONSHIP BETWEEN CRITICAL ANGLE FOR OCCURRENCE OF DEBRIS FLOW AND WATER CONTENT IN UNSATURATED DEPOSITS

10.29417/JCSWC.199305_24(1).0003

黃宏斌(Hung-Pin Huang)

土石流 ； 非飽和堆積層 ； Debris Flow ； Unsaturated Deposits

中華水土保持學報

24卷1期（1993 / 05 / 01）

21 - 27

繁體中文

土石流發生之力學特性，主要爲堆積層沿斜面之推移力大於堆積土體本身之抗剪力，而產生破壞，並隨卽以混合之土砂及石礫，以流體之狀態，持續地往下游移動。由於含黏土礦物之土壤，其抗剪強度會隨含水量之增加而降低；礫石土因其無黏土礦物之成份，且其入滲容易，所以，含水量對其抗剪強度之影響不顯著。本研究主要藉由渠槽試驗探討含黏土礦物之非飽和堆積層之含水量與土石流發生之臨界角度間之關係。當含水量之範圍自21至27％時，本研究得到林口台地土樣發生土石流之臨界角度θ與含水量ω之關係式如下：θ=123.73-35.49lnω

The mechanism for occurrence of debris flow was principally that driving force along deposits was larger than its shear strength and deposits itself then moved as a fluid flow by mixture of soil and gravel. In accordance with literature review, the shear strength of soil including clay minerals would decrease with water content; while that of gravel was insignificant with water content because it was easier to be percolated through and was not including clay minerals.