Abstract
Engineering simulation tools for predicting the flow and deposition behavior of debris flows make use of
simple rheologic flow laws describing flow resistance. In this contribution we test the possibility to
parameterize simple flow models by laboratory investigations. We estimate parameters for the Bingham
model from a suite of laboratory experiments in different setups. Material samples were taken from fresh
deposits of a muddy debris flow and analyzed over a range of volumetric sediment concentrations and
maximum grain sizes. Our results are relatively consistent between most setups. Estimated rheologic
parameters show an exponential dependence on volumetric sediment concentration and a systematic
variation for mixtures of different maximum grain sizes. Though a rheologic interpretation of bulk flow
behavior seems feasible at the laboratory scale, extrapolation of rheologic parameters to prototype flow
situation for direct use in numerical simulation tools is not recommended.
