Search

Copyright of Italian Journal of Engineering Geology & Environment is the property of Sapienza Universita di Roma and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Historical movement of the Montaguto earth flow in southern Italy has periodically destroyed residences and farmland, and damaged the Italian National Road SS90 and the Benevento-Foggia National Railway. This paper provides maps from an investigation into the evolution of the Montaguto earth flow from 1954 to 2010. We used aerial photos, topographic maps, LiDAR data, satellite images, and field observations to produce multi-temporal maps. The maps show the spatial and temporal distribution of back-tilted surfaces, flank ridges, and normal, thrust, and strike-slip faults. Springs, creeks, and ponds are also shown on the maps. The maps provide a basis for interpreting how basal and lateral boundary geometries influence earth-flow behavior and surface-water hydrology. [ABSTRACT FROM AUTHOR]

In October 2015, two intense rainfall events hit the central and southern regions of Italy and triggered a combination of different and widespread effects, including floods, landslides, and soil erosion. These outcomes devastated about 68 municipalities of the Benevento province (Campania region), killed two people, and caused millions of euros worth of damage to structures, infrastructures, and agriculture. The town of Benevento was one of the sectors most affected by overflow. Extensive areas characterized by flyschoid outcrops experienced widespread occurrences of soil erosion and landslides, and destructive, high-velocity debris flows (about 50) afflicted areas that had experienced heavy rainfall of higher intensity (total rainfall of 415.6 mm). In this study, the characteristics of these rainfall events and related geomorphological processes were determined by (i) analyzing the available rainfall data to identify the spatial pattern, distribution, and statistical characteristics of the two storms and (ii) mapping the storm effects, such as flooded areas, landslide types, and soil erosion. These effects were then related to the spatial distribution of the storms and the local geological and geomorphologic settings that drove their initiation and development. [ABSTRACT FROM AUTHOR]

We investigated relations between slip-surface geometry and deformational structures and hydrologic features at the Montaguto earth flow in southern Italy between 1954 and 2010. We used 25 boreholes, 15 static cone-penetration tests, and 22 shallow-seismic profiles to define the geometry of basal- and lateral-slip surfaces; and 9 multitemporal maps to quantify the spatial and temporal distribution of normal faults, thrust faults, back-tilted surfaces, strike-slip faults, flank ridges, folds, ponds, and springs. We infer that the slip surface is a repeating series of steeply sloping surfaces (risers) and gently sloping surfaces (treads). Stretching of earth-flow material created normal faults at risers, and shortening of earth-flow material created thrust faults, back-tilted surfaces, and ponds at treads. Individual pairs of risers and treads formed quasi-discrete kinematic zones within the earth flow that operated in unison to transmit pulses of sediment along the length of the flow. The locations of strike-slip faults, flank ridges, and folds were not controlled by basal-slip surface topography but were instead dependent on earth-flow volume and lateral changes in the direction of the earth-flow travel path. The earth-flow travel path was strongly influenced by inactive earth-flow deposits and pre-earth-flow drainages whose positions were determined by tectonic structures. The implications of our results that may be applicable to other earth flows are that structures with strikes normal to the direction of earth-flow motion (e.g., normal faults and thrust faults) can be used as a guide to the geometry of basal-slip surfaces, but that depths to the slip surface (i.e., the thickness of an earth flow) will vary as sediment pulses are transmitted through a flow. [ABSTRACT FROM AUTHOR]

This work aims at understanding the potential of ambient vibration monitoring in deriving information about material properties change related to landslide seasonal behaviour and resonance directivity in landslides. The case study is the Pietrafitta landslide in southern Italy, known for its effects on the SS87 National Road and for being influenced by artificial vibrations. The field experiment consisted in four two-day-long measurement cycles, completed between April and November 2016, by using two broad-band three components velocimetric stations: one station at the landslide's toe and a reference station outside the landslide. Obtained data were analysed in terms of root mean square, spectral amplitude, horizontal-to-vertical spectral ratio and directionality effects. Results indicated the existence of amplitude daily variations due to vehicular traffic for both the stations, and long-time variations in the amplitudes and frequency content at the landslide site. Polarization and directional resonance showed a daily variation, with the most coherent results in the range of 20° - 60° at the night hours, in the absence of traffic. This azimuthal trend was transverse to the sliding direction. The most marked resonance effect was found in the April recordings. The observed horizontal-to-vertical spectral ratio curves changed over time, due to variation in shear stiffness related to seasonal consolidation. Results from the horizontal-to-vertical spectral ratio inversion suggested a decrease from April to October 2016 in the Vp / Vs ratio, and in the velocity contrast at the base of the sediments consistent with common decrease in landslide activity due to summer drought. • We monitored ambient vibrations at an active landslide in Southern Italy. • We applied HVSR inversion, time-domain polarization, and HVSR directivity methods. • Resonance directivity shows a dominant direction transverse to the landslide sliding. • We attributed the HVSR time variations to variations in the materials properties. [ABSTRACT FROM AUTHOR]