对蒋家沟流域泥石流源区两种分散性不同的土(G1土具有强分散性,G2土无分散性)进行室内土柱自滤试验,研究了土柱在常水头(水头为5 cm)渗流过程中颗粒运移对土柱不同部位渗透性的影响。入渗液采用了煮沸过的清水与浓度为1 g/L的悬浮液(悬浮颗粒的粒径范围为1.6～104.74μm)。在清水渗流过程中,两种土样的入口处土层渗透性随着时间而增大,出口处土层的渗透性先增大后减少。在悬浮液渗流过程中,两种土的各土层的渗透性都有下降趋势,但在入口处土层最为显著,G1土样下降了一个数量级以上,G2下降了近两个数量级,且G2土所用时间较G1土短,即G2土的渗透性减少速率更加明显;两土柱中渗透流量都有显著减少。研究表明:土体的分散性在颗粒运移过程逐渐占主导地位,即强分散性土自身颗粒的运移明显,能抵消一部分外来颗粒的积聚堵塞作用。从试验结束后土柱的外观图像观察也发现,入渗的悬浮颗粒在土柱的各个位置都有分布,但主要沉积在入口处,这与土柱各层渗透性的变化相吻合。此外,两种土流失的颗粒都只是集中于渗流的开始阶段,流失颗粒粒径范围集中在数微米至数十微米之间。 Soil column self-filtration tests were carried out on two kinds of soil with different dispersibility in the debris flow source area of ​​the Jiangjiagou watershed (G1 soil with strong dispersibility and G2 soil non-dispersibility) INFLUENCE OF PARTICLE TRANSPORT ON PERMEABILITY OF DIFFERENT SITES IN SOIL COLUMN DURING SEEPAGE. The infiltrated liquid used boiled water and a suspension with a concentration of 1 g / L (the particle size of the suspended particles ranged from 1.6 to 104.74 μm). During the seepage process of clear water, the permeability of soil layers at the entrance of the two kinds of soil samples increases with time, and the permeability of the soil layer at the exit first increases and then decreases. In the process of seepage, the permeability of each soil layer in both soils tended to decrease, but the soil layer was the most prominent at the entrance. The soil samples in G1 dropped by more than one order of magnitude and G2 dropped by nearly two orders of magnitude. The soil use time is shorter than that of G1 soil, that is to say, the rate of decrease of permeability of G2 soil is more obvious. The permeation flux of both soil columns is significantly reduced. The results show that the dispersibility of soil gradually dominates in the process of particle migration, that is, the migration of strong disperse soil particles is obvious, which can offset the accumulation and blockage of some foreign particles. Observation of the appearance of soil column after the end of the experiment also found that infiltration of suspended particles in the soil column are distributed in various locations, but mainly deposited at the entrance, which coincides with the permeability of soil column changes. In addition, both types of soil loss particles are only concentrated in the initial stage of seepage flow, the size of the lost particles concentrated in the range of several microns to tens of microns.