RAIN EROSION RESISTANCE OF DEBRIS FLOW FAN SPRAYED BY SH AGENT ON SURFACE

The key to debris flow initiation is rain erosion and infiltration. With the controllable intensity artificial rainfall experiment, debris flow alluvium of Zhangye City, Gansu Province was chosen as media to study rainfall erosion-resistant on the 100 mm·h^-1 heavy rain conditions. And debris flow alluvium was sprayed on surface with SH agents. The results of this study are as follows. The untreated soil surfaces were eroded obviously and formed several erosion gullies and it had a large number of erosion particles in bottom. However, soil treated with SH agent had significantly rainfall erosion-resistant. The protective layer formed by SH agent connecting soil particles had strong adhesion. There were no obvious trances and only a few erosion particles existed. Moreover, rainfall erosion-resistant first was strengthened then stabilized with increasing SH amounts."Mosaic structure" layer formed on silt and sand soil were more stable than that of "floating structure" layer formed on gravely soil. The rainfall erosion-resistant was effected by SH agent amounts and soil types. Considering of aspects of cost and rainfall erosion-resistant etc., the findings suggest that a SH agent amount of 1.0 kg·m^-2 would be ideal for silt and sand soil, but need aptly to increase SH agent amounts for gravely soil.