A new energy index for evaluating the tendency of rockburst and its engineering application

Based on energy-transfer analysis of triaxial unloading tests under four different controlling conditions, the rock burst energy release rate (RBERR)-an energy index combining the local energy release rate (LERR) and the limit energy storage rate (LESR), was proposed. LERR refers to the values of the elastic strain energy release of an element after brittle failure, which indicates that RBERR > 0 can be used to determine whether the element belongs to an excavation damage zone. RBERR was implemented to simulate the evolution process of rock damage and failure with advancing excavation face. The results predicted using RBERR were consistent with those obtained from an actual rockburst. In addition, a synthesis method based on microseismic (MS) monitoring information and RBERR simulation analysis was implemented for the Huainan coal mine. A study on the spatial- temporal evolutional laws of MS events built relationships between MS monitoring information and excavation process and; consequently, the potential danger areas of rockburst were determined. RBERR was used to analyze the location and intensity of rockburst in potential danger areas, which could be valuable in the design of rockburst- resistant measures in deep- buried construction.