Flume Modeling of Debris Flows

Debris flows are unique compared to other types of landslides (e.g., rock avalanches; dry granular flows) because their dynamics are governed by both the soil grains and interstitial fluid. On one hand, debris flows may exhibit some features of dry granular flows, such as particle size segregation. On the other hand, contact and collisional grain stresses are strongly influenced by the viscosity and excess pressure of the interstitial fluid. Furthermore, debris flows travel over complex erodible boundaries and have been reported to reach volumes of up to 109 m3 and travel over 100 km. Evidently, the scale and dynamics of debris flows are complex and difficult to reproduce. One of the most common approaches to investigate the dynamics of debris flows is by conducting scaled laboratory experiments, which provide idealized and high-quality evidence to evaluate theoretical and numerical models. This chapter provides an overview of the fundamental principles, scaling considerations, commonly adopted setups (e.g., flumes and geotechnical centrifuge), and the state-of-the-art in instrumentation and image analysis for modeling debris flows.