Assessment of post-failure evolution of a large earthflow through field monitoring and numerical modelling

P Lollino,P Allasia,N L Fazio,M Perrotti,F Cafaro,D Giordan

doi:10.1007/s10346-020-01415-5

Abstract

The analysis of the residual hazard existing after the emergency phases generated by the activation or reactivation of landslides is rarely taken into account in a proper manner. However, the assessment of landslide post-failure evolution should represent a key factor to control potential landslide reactivations and prevent new landslide-induced damages. This paper presents the results of a long-term field monitoring activity performed in the years after the emergency phase of the Montaguto (Italy) earthflow reactivation occurred in 2010 as well as the results of 2-D and 3-D numerical analyses aimed at interpreting the post-emergency landslide behaviour. The results of the numerical simulations, which agree well with the in situ monitoring data, allow to define a conceptual model of the earthflow behaviour that is related to the pore water pressure variations resulting from the drained or undrained processes occurring in the landslide body. The study proposed confirms a general reduction of the landslide activity, as well as allows to detect the factors that control the residual activity existing in a specific area of the landslide and to infer possible critical scenarios for landslide reactivations.

Highlights

The application of real-time or near real-time monitoring is widely considered to be the most efficient way to control the hazard associated with the unstable areas of a landslide during the most critical phases, and to support the risk management related to the landslide failure (Manconi and Giordan 2016)
Starting from the outcomes of the monitoring activity and the numerical study, we present some indications in terms of residual hazard associated with the earthflow activity as well as possible future scenarios of landslide evolution
Discussion and concluding remarks In this paper, the behaviour of the Montaguto earthflow in the post-failure phase, as resulting from a large monitoring dataset acquired in several years and from the results of numerical analyses, has been presented and discussed

Summary

Introduction

The application of real-time or near real-time monitoring is widely considered to be the most efficient way to control the hazard associated with the unstable areas of a landslide during the most critical phases, and to support the risk management related to the landslide failure (Manconi and Giordan 2016).

Results

Conclusion