崩塌土流动化机理的实验研究

Experimental study on flow mechanism of avalanche soils

作者利用可调坡水槽进行了松散崩塌土与水流掺混并形成泥石流的实验 ,观测了崩塌土运动距离及泥石流的形成过程 ,建立了崩塌土流高比的计算公式。讨论了松散崩塌土流动化形成泥石流的临界条件 ,提出松散崩塌土在一定纵坡下形成泥石流的水流掺混机理。实验中发现了一定形状的块状崩塌土与饱和度较高的下垫层之间存在超载孔隙水压力 ,超载孔隙水压力减轻了块体自重达到减阻的作用。从而 。

The transportation distance of avalanche soils and formation process of debris flow are investigated in a flume with variable slope. Empirical formula for ratio of collapsed height to run-out amount of avalanche soils is established. It is found that the supernormal pore water pressure between the avalanche soil blocks and highly saturated underlay can reduce the weight of blocks, so that the resistance between avalanche block and highly saturated underlay will be reduced. This esplains the cause of block avalanche soils rapidly move to the surface of debris flows. The critical condition of debris flow formed by avalanche soils is also discussed.