Modelling and Simulation of Rockfall using Nonsmooth Dynamics

Rockfall is a significant natural hazard in mountainous areas posing a major threat to infrastructure, transportation lines, and human safety. Simulation techniques to predict rockfall trajectories in complex three-dimensional terrain have great practical value as they can be used to determine the danger of rockfall run-out zones as well as to dimension protection measures. Rockfall research has been dominated in the past by simple point mass and 2D models because of their computational efficiency. Moreover, most existing 3D rockfall simulation tools either neglect the detailed influence of rock shape on inertia properties, contact detection, and contact laws or are restricted to overly simplified rock geometries. A full 3D simulation technique for rockfall dynamics, taking rock shape into account and using the state-of-the-art methods of Multibody Dynamics and Nonsmooth Dynamics, has been developed at the SLF in close cooperation with ETH (and now the University of Stuttgart).

In this talk, we will first discuss the essential features of Nonsmooth Dynamics and how it can deal with hard contact laws described by set-valued graphs. Then we will look at the challenges which arise when we apply this framework to the trajectory simulation of rockfall. Finally, we will discuss why the detailed modelling and consideration of rock shape is quintessential in various aspects of rockfall research.