Abstract:
The temporal and spatial evolution laws of damage and failure precursory characteristics of rock mass are of great significance to the identification, prediction, prevention and control of rock disasters. Based on acoustic emission (AE) experiment, the damage temporal and spatial evolution law and failure characteristics were studied in this paper. The results are as following: the damage of sandstone evolves continuously in time and space, and there is a sudden change in the speed of damage development at the key moment. The main crack grows from the “gathering” region and extends to the periphery, ultimately penetrating the simplein axial and radial direction; the AE events with high energy usually appear in the period of rapid expansion of damage, and the location points of the AE events are mainly distributed in the internal damage concentration area, which could be used as an important reference for damage conduction and accumulation; the high frequency appearance of high-energy AE signals could be regarded as precursor information of sandstone failure and instability in temporal domain, while in spatial domain, the spatial density of high-energy AE events would be provided as reference to judge the initial area of sandstone failure.