Numerical modelling of mudflows impacting settlements: a case study
- 1University of Sheffield, Department of Civil and Structural Engineering, Mappin Street, S1 3JD, Sheffield UK
- 2Politecnico di Torino, Department of Structural, Geotechnical and Building Engineering, Corso Duca degli Abruzzi 24, Torino, Italy
Mudflows are common natural hazards, often originating from the liquefaction of shallow landslides triggered by rainfall. The numerical back-analysis of past events is key in projecting the application of numerical models towards forward analysis. However, the complex multi-physics nature of the problem hampers the development of comprehensive frameworks. Notwithstanding, calibrated numerical models, able to simulate all aspects of the problem (triggering and runout) can still be valuable tools for aiding the design of countermeasures. This can currently only happen if calibration is performed on the specific site, or on sites with very similar geomorphological and geological characteristics.
In this presentation, the application of a coupled triggering and runout model is explored. Two study cases of well-known events occurring in Southern Italy are presented. A pseudo-plastic model is used for the post-triggering rheology. The resolution of the runout simulation is down to the level of the specific exposed element (houses, roads). This allows for an ad-hoc assessment of risk on key pieces of infrastructure. The results reveal interesting aspects related to how the complex topographic features of settlements challenge the traditional workflow for back-analysis. In particular, the channelization of flows within the settlement itself leads to an overestimation of hazard, unless care is placed to resolve the triggering phase down to the sub-basin scale.
REFERENCES
Ng, C. W. W., Leonardi, A., Majeed, U., Pirulli, M., & Choi, C. E. (2023). A Physical and Numerical Investigation of Flow–Barrier Interaction for the Design of a Multiple-Barrier System. Journal of Geotechnical and Geoenvironmental Engineering, 149(1). https://doi.org/10.1061/(asce)gt.1943-5606.0002932
Pasqua, A., Leonardi, A., & Pirulli, M. (2022). Coupling Depth-Averaged and 3D numerical models for the simulation of granular flows. Computers and Geotechnics, January, 104879. https://doi.org/10.1016/j.compgeo.2022.104879
How to cite: Leonardi, A., La Porta, G., and Pirulli, M.: Numerical modelling of mudflows impacting settlements: a case study, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16166, https://doi.org/10.5194/egusphere-egu23-16166, 2023.
