Modelling rockfall impact with scarring in compactable soils

• DOI: 10.1007/s10346-019-01238-z
• Publication Date: 2019-07-20T15:02:21Z
• Authors: Guang Lu; Andrin Caviezel; Marc Christen; Sophia E. Demmel; Adrian Ringenbach; Yves Bühler; Claire E. Dinneen; Werner Gerber; Perry Bartelt
• Keywords: 0211 other engineering and technologies; 02 engineering and technology

An accurate modelling of rockfall runout continues to be a demanding challenge within the geotechnical and hazards engineering community. Most existing rockfall dynamic programs apply effective restitution coefficients to model the energy dissipation during the rock-ground interaction. Recent experimental measurements, however, reveal the limitations of effective restitution coefficients, especially to account for scarring with frictional rebound in soft compactable soils. This study proposes a three-dimensional, non-smooth computational mechanic approach to model dissipative rock-ground interactions in soft compactable soils. The ground is mathematically divided into a soft, compactable scarring layer and a hard rebound layer. The model considers the plastic deformation of the ground with rotating rocks of general, non-spherical shape. The simulated rockfall energy dissipation is validated at both the single impact and multi-impact levels using induced 780-kg rockfall experiments performed at Chant Sura, Switzerland, in 2018. Overall, the numerical results are in good quantitative agreement with the experimental measurements. Ongoing improvements of the scar drag model are to integrate rotational drag into the rock energy dissipation term, and to calibrate the drag parameters in depths using repetitive rockfall experiments spanning a greater range of rock shapes and masses.