Damage In Rock Massives, Evidences From Microseismic Monitoring and Numerical Modelling

Abstract:

Damage is an active process in rock massives that can progressively lead to their collapse. Microseismic monitoring appears as a powerful tool for detecting damage and identifying the parameters controlling its occurrence parameter. In this presentation, we first present results of seismic monitoring performed on different sites and highlighting different control parameters, including freezing/thawing cycling, long term creeping, rainfall. These observations reveal common features as power-law distribution of the seismic event size and of their temporal distribution. The evolution of these distributions can be used for forecasting the failure, as successfully tested on a cliff that undergone macroscopic failure.

In a second part we present numerical modelling of damage that successfully reproduce the major part of the in-situ observations. The simulations based on short or long term damage and taking into account the action of fluids, have been applied to realistic cases and show promising results in good agreements with field observation.