Effect of sieving methods on grain size distribution of fragmental debris- A case study of Jiangjia Gully Debris flow deposit

To explore the effect of sieving methods on grain size characteristics of debris flow deposits, the particle distribution of the Jiangjia gully debris flow in Yunnan Province was analyzed using dry sieving, wet sieving, and combined sieving methods. Meanwhile, the particle size boundaries under different sieving weights and sieving methods were determined using a laser particle size analyzer. Based on the analysis of different physical and mechanical indicators, the gradation characteristics of coarse grains ( d < 60.00 mm) and fine-grained slurry ( d < 2.50 mm) of debris flow deposits are revealed. The results indicate that the sieving effect has a significant impact on the gradation characteristics and grain size properties of debris flows. The research results further clarify the effect of sieving on the analysis of particle size characteristics of debris flow deposits, and provided a research basis for the in-depth revelation of the occurrence-transport-accumulation mechanism of the debris flow.