3D analysis of a fragmental rockfall

The final authenticated version is available online at https://doi.org/10.1007/978-3-030-60706-7_15.Fragmentation in a rockfall event influence the total number of fragments, the mass distribution, and the impact energies and runouts. Then, the probability of impact and hazard characterization should consider fragmentation. A fractal fragmentation model has been proposed in order to reproduce the phenomenon. The Rockfall Fractal Fragmentation Model has been implemented in a 3D rockfall propagation simulator named RockGIS. We present the analysis of a fragmental rockfall that occurred in Mallorca, Spain. Fieldworks are carried out in order to obtain the block size distribution of the rockfall deposit. A 3D terrain model is obtained using UAV surveys and digital photogrammetric techniques. The obtained 3D point cloud is cleaned of vegetation and used to create a Digital Elevation Model (DEM). The fragmentation model parameters and the propagation simulator coefficients have been calibrated to accomplish both, the resultant block size distribution and the runout distance of the blocks. The obtained results show a good reproduction of the fragmental rockfall studied. After the calibration is accomplished, older and future rockfalls in the cliff may be analyzed, considering thousands or single blocks simulations with or without fragmentation.This study was supported by the research project RockModels (Ref.BIA2016-75668-P, AEI/FEDER.UE) funded by the Spanish Ministry of Economy and Competitiveness. Acknowledge also, to the local government of Mallorca (Balearic Islands, Spain).Postprint (author's final draft