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Research Project : Investigation of viscosity in granular debris flows and interactions with natural mitigation

Debris flows are highly saturated flows of soil material originating from a slope instability failure. The finer materials travelling in the flow, clays and silts, increase the fluid viscosity and can produce a shear-thinning behaviour, meaning a reduction in this viscosity as flow is sheared. This research project aims to investigate the presence of the suspension of fine material on the behaviour of debris flows. The key areas of interest include grain-grain and grain-fluid interactions and the effects on macro-scale attributes of the phenomena such as runout length. Research tools used in this project will include small-scale physical models and DEM-LBM simulations. These natural hazards are high risk and often require physical mitigation strategies, such as silt barriers and baffles, to reduce energy and retain flow. This project intends to assess the arrangement of a natural baffle type structure for the effectiveness in flow energy reduction. A physical model will be developed from attributes of a living forest to allow application of this study to a more sustainable solution to debris flow mitigation, with the observed behaviours re-assessed using an LBM numerical model.

Supervisors : Dr Alessandro Leonardi & Dr Elisabeth Bowman

Research Interests :

• Physical and numerical modelling of debris flows

• Depth-averaging numerical tools & DEM-LBM

• Rheological behaviour of clay and silt particle suspensions

• Physical modelling and design for structural mitigation strategies to reduce flow energy and runout lengths