ANALYSIS ON SENSITIVITY OF RHEOLOGICAL PARAMETERS TO DEBRIS FLOW

Reasonable selection of rheological parameters may play a role in delineating the runout process mobility behavior of debris flow and high speed and long distance landslide. In this study, three-dimensional continuum model simulation method is applied using voellmy model and analysis of variance, to study the dynamic process under different rheological parameters, and to a compare the sensitivity degree of rheological parameters to runout behavior. The results show that dynamic basal friction angle and turbulence coefficient can influence the dynamic characteristics of debris flow and high speed and long distance landslide to a different degree. The higher dynamic basal friction angle will produce bigger and faster energy dissipation process, making the whole movement process lag; the higher turbulence coefficient increased strength momentum exchange between the fluid layers, with great ability to mix media around, and increased entrainment effect. The basal topography is an important factor influencing the debris transportation and deposition processes. The underlying surface conditions, particles of debris, pore water pressure has a very close connection with velocity, runout distance and deposition area, volume, and can affect the debris intensity and disaster area and scale to a large extent. The proposed suggestions can be estimated conveniently in general geotechnical practices and can provide the scientific basis for regional disaster prevention and reduction and scientific research.