The Dynamic Process and Sensitivity Analysis for Debris Flow

The dynamic process and sensitivity in the debris transportation process are important topics in the study of rapid landslides and debris flows. The motion process of debris flow is recognised as a dynamic interaction between the original moving material and the entrained basal topsoil shearing along their non-slip contact surface. In this paper, we employed numerical modelling to clarify the erosional effects, and use statistical method to compare the influence degree of rheological parameters on the runout behavior. The simulated results show that unconfined flows typically exhibit a wide range of entrainment and deposition volume, whereas confined flows yield moderate volumes of entrainment and small volumes of deposition. The basal topography is an important factor in influencing the debris transportation and deposition processes. The velocity, runout distance, and deposition area and volume are more sensitive to underlying surface conditions, particles of debris, pore water pressure; and can affect the debris intensity, disaster area and scale to a large extent. Conversely, the velocity, runout distance, and deposition area and volume, are less sensitive to the source volume of debris flows, and can only affect the velocity to a little extent. The proposed suggestions can be utilized conveniently in general geotechnical engineering practices.