Study on Seepage-Induced Debris Flows Initiation under the Rainfall Action for Loose Soil

Test soils were collected from a debris flow source area in the Weijia groove, Beichuan County, Sichuan Province. An indoor artificial rainfall model tank test has been designed; it can be used to simulate the process of debris flow initiation for slope loose soil under the rainfall action. The debris flow starting condition and confluence process have been measured in this test through the analysis of the relationship of the rainfall intensity, duration time before the starting, and the total rainfall capacity at the starting moment, the relationship between the volume of production flow and the wate-to-soil ratio in production flow. All these research results can be used to simulate debris flow initiation mechanism obtained from model test focused on the seepage-induced action and its influence factors.