The paper focuses on a geotechnical approach for debris flow analysis in weathered gneiss. The proposed methodology combines two physically based models “Transient Rainfall Infiltration and Grid-Based Re-gional Slope-Stability Analysis” (TRIGRS) and “Smoothed Particle Hydrodynamics” (SPH), for respective-ly analysing the triggering and propagation stages of landslide. The TRIGRS analyses provided information about the location and initial triggering volume of potential landslides. The SPH model, adopting the initial triggering volume as input data, allowed the back analysis of the propagation stage in terms of both main pathway and depositional area. The proposed methodology can be implemented over large areas for landslide susceptibility zoning and it is able to provide interesting information for land use planning. The availability of geotechnical data ob-tained from in situ and laboratory tests is a key aspect for a rigorous implementation of the methodology. When these data are not available, literature data obtained for similar soils for genesis and stress history with those studied can be used. The applicability of the methodology has been tested on two debris flows which caused extensive damage involving various lifelines in 2001 and 2005 in the province of Reggio Calabria. The model results have been validated on these debris flows, in terms of both inception areas and debris fans using two dimensionless indices (Itrig and Idep). These indices compared, respectively, the real inception area with the simulated one and the real depositional area with the numerical one. The obtained results (Itrig> 90% and Idep >70%) sup-port the applicability of the proposed methodology.
A geotechnical approach for landslide analysis at basin scale.
Ciurleo M.
Primo
Writing – Original Draft Preparation
;
2021
Abstract
The paper focuses on a geotechnical approach for debris flow analysis in weathered gneiss. The proposed methodology combines two physically based models “Transient Rainfall Infiltration and Grid-Based Re-gional Slope-Stability Analysis” (TRIGRS) and “Smoothed Particle Hydrodynamics” (SPH), for respective-ly analysing the triggering and propagation stages of landslide. The TRIGRS analyses provided information about the location and initial triggering volume of potential landslides. The SPH model, adopting the initial triggering volume as input data, allowed the back analysis of the propagation stage in terms of both main pathway and depositional area. The proposed methodology can be implemented over large areas for landslide susceptibility zoning and it is able to provide interesting information for land use planning. The availability of geotechnical data ob-tained from in situ and laboratory tests is a key aspect for a rigorous implementation of the methodology. When these data are not available, literature data obtained for similar soils for genesis and stress history with those studied can be used. The applicability of the methodology has been tested on two debris flows which caused extensive damage involving various lifelines in 2001 and 2005 in the province of Reggio Calabria. The model results have been validated on these debris flows, in terms of both inception areas and debris fans using two dimensionless indices (Itrig and Idep). These indices compared, respectively, the real inception area with the simulated one and the real depositional area with the numerical one. The obtained results (Itrig> 90% and Idep >70%) sup-port the applicability of the proposed methodology.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
