Long-Term Continuous Monitoring of a Deep-Seated Compound Rock Slide in the Northern Apennines (Italy)

An automated total station monitored a compound rock slide near the Cerreto Pass (northern Apennines, Italy) for more than three and a half years. The rock slide, which threatens national road SS63, has an estimated volume of more than 3 million m3 and is composed by the overlap of highly fractured limestone on an impermeable and weak clay shale layer. Specifically, a network of more than 30 prisms has been measured every 2 h from October 2009 to May 2013. This dataset provides substantial evidence of displacement rates up to 15 cm/year and gives information about the control of rainfall on slope movements. On the yearly scale the seasonal variation of rainfall regime determines the baseline displacement rate of the rockslide while moving to shorter time spans has been possible to individuate effects of rain episodes calculated on daily and weekly sampling. Results highlight the added value of continuous monitoring for assessing rock slide dynamics and improving hazard assessment.