The analysis of rockfall risk along transportation facitities and residential areas requires the identification of potential unstable blocks and the modelling of rockfall runout in order to quantify the expected damages to structures and to support the design of countermeasures. This paper presents several approaches for the characterization of rockfall hazard for the southwestern slope of Mont La Saxe (Courmayeur, Aosta Valley, Western Italian Alps), from where several blocks detached in 2011, causing one victim and the interruption of the main road for almost one year. The propagation of each block over a complex topography represented by a 2 m gridded LiDAR DEM was simulated by using the 3D rockfall simulation model Hy-STONE (Crosta et al. Geophys Res Abstr 6: 04502, 2004). 330,180 blocks were simulated using a stochastic approach for restitution and friction coefficients in order to account for uncertainty in model parameters. For the main road and the exposed buildings, a detailed analysis has been performed, by mapping the type of impact, the kinetic energy and the velocity of blocks potentially impacting the structures and the height of trajectories passing through. For the most exposed elements, energies in excess to 10,000 kJ, and heights up to 50 m above the ground were foreseen by the simulation. These results showed that a mitigation strategy was necessary to protect the road and the residential buildings. In order to support the dimensioning and the correct positioning of these countermeasures and to verify the efficiency of the works, we performed a number of simulations, including in the model the designed countermeasures.
Frattini, P., Crosta, G., Valagussa, A. (2014). Rockfall runout modelling for hazard characterization and countermeasure design in urban area. In Landslide Science for a Safer Geoenvironment: Volume 3: Targeted Landslides (pp.385-391). Springer International Publishing [10.1007/978-3-319-04996-0_59].
Rockfall runout modelling for hazard characterization and countermeasure design in urban area
FRATTINI, PAOLO
;CROSTA, GIOVANNISecondo
;VALAGUSSA, ANDREAUltimo
2014
Abstract
The analysis of rockfall risk along transportation facitities and residential areas requires the identification of potential unstable blocks and the modelling of rockfall runout in order to quantify the expected damages to structures and to support the design of countermeasures. This paper presents several approaches for the characterization of rockfall hazard for the southwestern slope of Mont La Saxe (Courmayeur, Aosta Valley, Western Italian Alps), from where several blocks detached in 2011, causing one victim and the interruption of the main road for almost one year. The propagation of each block over a complex topography represented by a 2 m gridded LiDAR DEM was simulated by using the 3D rockfall simulation model Hy-STONE (Crosta et al. Geophys Res Abstr 6: 04502, 2004). 330,180 blocks were simulated using a stochastic approach for restitution and friction coefficients in order to account for uncertainty in model parameters. For the main road and the exposed buildings, a detailed analysis has been performed, by mapping the type of impact, the kinetic energy and the velocity of blocks potentially impacting the structures and the height of trajectories passing through. For the most exposed elements, energies in excess to 10,000 kJ, and heights up to 50 m above the ground were foreseen by the simulation. These results showed that a mitigation strategy was necessary to protect the road and the residential buildings. In order to support the dimensioning and the correct positioning of these countermeasures and to verify the efficiency of the works, we performed a number of simulations, including in the model the designed countermeasures.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.