Investigation of the geomechanical aspects of a large landslide by means of a finite-element method: a case study

Using advanced geomechanical finite element modelling, it has been possible to simulate the mechanical behaviour of a large slope movement, namely the Triesenberg landslide. This slope is located along the Rhine valley in the Principality of Liechtenstein, covering an area of around 5 km2 which includes two villages. Pore water pressure fields calculated by a separated hydrogeological model were used as an input for the geomechanical model. The results obtained through 2- and 3-dimension numerical simulations agree fairly well with field measurements of peak velocity, spatial and temporal distribution of velocity and total displacements. Such results were obtained using a Modified Cam-Clay elasto-plastic constitutive model. In addition, a parametric study has been carried out to evaluate the effect of the selected friction angle and of the range of water pressure variation on the movements during a crisis period.