Indeterminacy of displacement and stress of geologic rock mass system in the critically non-stationary state: implication on prediction of geo-hazards

Geologic rock mass system instability, which results in geo-hazards such as earthquakes and landslides, is a hot topic being discussed by geologists and engineers. Rock mass deformation in the critically unstable states is key to predict and analyze instability and failure of geologic rock mass system. Evolution of displacement and stress in the critically unstable state is important for human to judge geo-hazards occurrence. Here, we employed numerical simulation to conclude that both direction and magnitude of displacement and stress, in any unit of geological rock mass, experience extremely stochastic rather than regular variation in the critically non-stationary state. The indeterminable variation is the typical characteristic of geologic rock mass deformation before approaching failure. We used the practical record data of a phosphate mine landslide in Hubei province and an earthquake in Sichuan province of China to verify the indeterminable change of displacement and stress before geo-hazards occurrence. The results illustrate that people can never predict correctly geo-hazards by parameters of displacement and stress from monitoring points because of indeterminable it is scientifically and economically impossible to judge the failure commencement of geologic rock mass using an infinite number of record points in such a huge geologic rock mass system. A possible research direction for predicting the instability of geologic rock mass system is the exploration of more suitable criterion based on random variation characteristics of displacement and stress from limitedly practical monitor points.