Integrated geostructural, seismic and infrared thermography surveys for the study of an unstable rock slope in the Peloritani Chain (NE Sicily)

This paper presents amultidisciplinary study about the instability of a rock slope on Peloritani Chain, northeasternSicily. Several rockfalls affected the studied slope in the last decades, also causing the disruption of the main road,connecting the shore villages to the city ofMessina. The complex geology and tectonics are the main causes of thepoor mechanical properties of the rocks, exacerbated by high fracturing and weathering. Geostructural surveysallowed identifying themain discontinuity sets,most ofwhichmatcheswith the regional fault systems. Kinematicand stability analyses were carried out to define the main failure typologies and to realize two models describingthe past rockfalls, as well as possible future events. For the deep investigation of the slope, horizontal boreholedrilling and seismic active prospecting were performed so to estimate the thickness of the rock with poormechanical properties. The contours of the most unstable areas along the slope have been better outlined throughinfrared thermography images, giving information about the thermal radiance behavior of the rock constitutingthe surface slope.The integrated approach of different methodologies, besides defining the instability features of the study area,demonstrates the reliability of such techniques, particularly in a geologically complex region where rockfallsrepresent one of the main causes of landslide fatalities