稀性泥石流龙头形成机制的试验研究

Experiments on the Surge of Un-coherent Debris Flow

本文通过室内槽子试验来观察和分析稀性泥石流阵性的形成机制。试验表明，稀性泥石流阵性的起因首先决定于流域内形成的原始出流过程。同时，运动过程中巨砾向龙头处集聚和泥石流体中液相介质向不饱和的床面堆积层的渗透流失，是促进龙头发展的二项重要因素。这二种作用使泥石流龙头部的固相浓度增大，粒径变粗，运动阻力增大，而使龙头壅高发展。本文根据龙头处粒经、浓度、阻力的变化来探讨龙头高度比正常流深增长幅度的计算方法。

The results of indoor trough experiments are described in this paper. It is made clear that the formation of debris surge is firstly determined by the original hydrograph of the basin. The accumulation of large particles at the surge front and the permeation downwards into the un-saturated bed layer are the two important factors that promote the development of debris surge. The action of these two factors enhances the concentration and size of solid particles in the surge head,hence the moving resistance increases and the surge head goes up.An estimation method for predicting the height of surge head has been established according to the degree of concentration and size of solid particles in the surge front.