CAREER: Experimental, Numerical, and Case Studies of Landslide Mobility

This Faculty Early Career Development (CAREER) Program grant will advance the understanding of landslide mobility. Rapid flow-like landslides such as mud flows, debris flows, and rock avalanches are capable of mobilizing large volumes of soil and rock and impacting large areas, often far from their source because of their high mobility. Globally, rapid flow-like landslides cause billions of dollars in damage and thousands of deaths and injuries each year. As evidenced by the recent Oso Landslide (March 22, 2014) in Snohomish County, Washington, landslide mobility remains poorly understood. This award supports fundamental research to provide the knowledge needed for advancing the understanding of landslide mobility, and reliably predicting landslide runout. Results from this research will improve current landslide hazard assessment and ultimately help reduce future losses to society from these devastating geohazards. The international component of this project will foster international collaborations that contribute to the training of globally-engaged engineering students.

The objective of this research is to advance the understanding of the effects of solid-like behaviors of landslide mass and fluid-solid interaction on landslide mobility, which play important roles but have been overlooked in the past. To achieve this objective, integrated experimental, numerical and case studies that span laboratory and field scales will be conducted. Laboratory-scale flume tests will be conducted to investigate the impact forces generated by a sliding mass on a rigid obstruction. The slide mass will have varied porosity, mass, and release height and pattern. In the numerical investigation, a three dimensional smoothed particle hydrodynamics model will be developed, which will incorporate the latest advancements in contact algorithms, formulations of landslide mobility, two-phase debris flow models, and parallel computing. The developed numerical model will be calibrated and validated against the laboratory-scale flume tests conducted in this research, well-documented field-scale flume tests conducted by others, and case histories of long-runout landslides. The fully validated numerical model will then be utilized to gain insights into the effects of internal stress field, fluid-solid interaction, and evolution of porosity, stiffness, and bulk density of the sliding mass on landslide mobility.