Clay landslide movement triggered by artificial vibrations: new insights from monitoring data

Abstract

Slope stability is influenced by a number of factors that modify the resisting/acting force ratio control landslide initiation and movement velocity. Among these, artificial vibrations have been identified as an important degrading factor for soil strength, but it is not fully clear if they can trigger or modulate movements of clay landslides. To contribute to a better understanding of the potential effect of vibrations on landslide movement, also in terms of boundary conditions, we analyzed monitoring data acquired at the toe of the Pietrafitta landslide in southern Italy. This landslide adjoins the SS87 national road that suffered periodic closure due to landslide activity and in April 2016 operates daytime only for risk mitigation purpose. This condition promoted a better identification of a potential cause-effect relation between traffic vibration and landslide movement. Results from data analysis and landslide modeling suggest that in condition of incipient movement, artificial vibrations, also of limited amplitude, are able to directly initiate clay landslide movement that due to the viscous nature of the involved material exhibit a specific displacement pattern that is not consistent with a sliding block model.

Seismic Advances in Process Geomorphology

“…By simultaneously monitoring both processes and conditions with the same data, one can more robustly link changing subsurface characteristics to geomorphic processes (e.g., Dietze et al 2020a). In addition, many of the external processes that force geomorphic events can also be observed with seismic data, such as heavy rainfall (Roth et al 2016), wind (Withers et al 1996), earthquakes, and anthropogenic activity (Guerriero et al 2021). Thus, well-designed seismic networks have the potential to simultaneously address each of the three areas described above-the triggering of discrete geomorphic events, their internal dynamics, and their impact in terms of sediment flux out of a catchment-while at the same time monitoring subsurface properties and some types of external forcing.…”

Remote Sensing Monitoring of the Pietrafitta Earth Flows in Southern Italy: An Integrated Approach Based on Multi-Sensor Data

“…T-InSAR displacement data between 21 and 22 April 2016 were also coherent with wire extensometer displacement data recorded in the same period at the site of the Pietrafitta earth flow. This instrument, used a seismic station, was installed along the left flank in Sector 3, in the context of the experiment conducted by [62], which aimed to demonstrate that, after 4-5 h of the night closure, the landslide movement stopped and then restarted simultaneously with the road day opening. This test proved that, even in the absence of rainfall events, the vibration induced by vehicle traffic acts as a trigger event of movement when geotechnical and geomorphological settings create ideal conditions for slope failure.…”

Instability Induced by Random Background Noise in a Delay Model of Landslide Dynamics

“…Landslides induced by external dynamical effects are common natural phenomena: there are many contemporary examples of massive landslides triggered by earthquakes [1][2][3], volcanic activity [4], or artificial vibrations [5,6]. The mechanism of the dynamically triggered events is obvious: if the impact is strong, then the intensity of the vibrations themselves is causing the soil failure.…”