Abstract:

Earthquake or strong rainfall can induce landslides. The landslide collapses to form clastic flow accumulation in the channels, forms debris flow under the action of the later rainfall. This is a type of debris flow which is called the landslide clastic accumulation of debris flow. The authors analyse characteristic parameters of the influence on starting of clastic accumulation of debris flow, research the information process of the landslide clastic accumulation of debris flow on the basis of experiments, and then analyse the influence of clastic accumulation surface slope, soil clay content, median grain size and non-uniformity coefficient on the formation of debris flow. The results show that the surface slope of clastic deposition have no significant effect on forming debris flow with discharge per unit width. The clay content are only affect clastic erosion at not more than 5%. It has no significant effect on digging up discharge per unit width. The main influence factors of required discharge per unit width are median diameter and non-uniformity coefficient width are increased with the increase of median diameter and non-uniformity coefficient. By fitting the experimental data, the formula of unit width discharge is obtained, which reflects the influence of median particle size and non-uniformity coefficient. For the formula only two main factors are considered width influence the formation of debris flow (d₅₀ and Cu). Therefore, the calculation results is smaller than hydrological calculation, but the overall trend is consistent. The formula can be applied in predicting this kind of debris flow after modificatin.

Key words: clastic deposition, debris-flow, grading, initiation flow, landslide