Riverbeds in Taiwan are full of granular materials such as boulder, cobble, gravel, sand, and silt. Under the action of floods, particles with their sizes from little to large will be floating upward and then flowing with floods gradually. Mechanical models for critical conditions of debris flows taken by some other researchers in Taiwan are mainly based on slope stability criteria. However real debris flows are generally observed to be initiated when granular soils start floating upward. Under

more »

... such circumstances, a more proper mechanical model was proposed by the authors. It was proved that such a model can provide proper solutions as compared with those produced from tests.