This paper analyses an important aspect of the continuum numerical modelling of rapid landslides as debris flows: “By using the same rheological parameter values, are the results obtained with codes that implement the same constitutive equations, but a different numerical solver, equal?” To answer this question, the two numerical codes RASH3D and GeoFlow_SPH are used here to back-analyse the debris flow event that occurred in the Nora stream (northwestern Italian Alps) in October 2000. Comparison of results evidenced that the RASH3D best-fit rheological values for the Nora event back-analysis overestimated both the final depositional heights and the simulated flow velocities if used in GeoFlow_SPH. To obtain thickness values comparable with those measured in situ, it was necessary to re-calibrate GeoFlow_SPH rheological parameter values. This way, with the exception of a larger lateral spreading of the sliding mass given by RASH3D, both thickness and velocity values were similar for the two numerical codes.

Comparison of two depth-averaged numerical models for debris flow runout estimation / Vagnon, Federico; Pirulli, Marina; Yague, Angel; Pastor, Manuel. - In: CANADIAN GEOTECHNICAL JOURNAL. - ISSN 0008-3674. - STAMPA. - 56:1(2019), pp. 89-101. [10.1139/cgj-2017-0455]

Comparison of two depth-averaged numerical models for debris flow runout estimation

Vagnon Federico;Pirulli Marina;
2019

Abstract

This paper analyses an important aspect of the continuum numerical modelling of rapid landslides as debris flows: “By using the same rheological parameter values, are the results obtained with codes that implement the same constitutive equations, but a different numerical solver, equal?” To answer this question, the two numerical codes RASH3D and GeoFlow_SPH are used here to back-analyse the debris flow event that occurred in the Nora stream (northwestern Italian Alps) in October 2000. Comparison of results evidenced that the RASH3D best-fit rheological values for the Nora event back-analysis overestimated both the final depositional heights and the simulated flow velocities if used in GeoFlow_SPH. To obtain thickness values comparable with those measured in situ, it was necessary to re-calibrate GeoFlow_SPH rheological parameter values. This way, with the exception of a larger lateral spreading of the sliding mass given by RASH3D, both thickness and velocity values were similar for the two numerical codes.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2732294
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