Preliminary results of a novel analytical approach to detect rock mass damaging from microseismic emissions

Rockfalls are a main hazardous source in mountainous areas and along transportation routes. These slope instabilities can be triggered by the jointed contribution of external solicitations, whether sporadic, like earthquakes and rainfalls, and continuous, like daily thermic variations and environmental vibrations. These actions cumulate strain effects over time resulting in rock mass damaging phenomena, intended as the formation of new fractures or as the movement and extension of the pre-existing ones. The microseismic monitoring of unstable portions of rock masses, thanks to the resolution and sensitivity of modern seismic devices, allows to record very weak seismic signals related to the deformational processes taking effect within the rock mass fractures network. In this study, a novel analytical tool is proposed and applied on a microseismic dataset acquired on a rock mass located in an experimental test site in central Italy. The damping parameters associated with the recorded microseismic emissions were analysed and compared over time, in order to relate potential variations of the long-time trend with rock mass damaging phenomena.