An Energy Preservation Index for Evaluating the Rockburst Potential Based on Energy Evolution

The estimation of rockburst potential has attracted great attention in the field of rock mechanics and engineering. In this study, an original energy preservation index is proposed to evaluate the rockburst potential in view of the energy evolution characteristics of rock materials. To investigate the energy evolution during rock deformation and failure, a number of cyclic uniaxial compression experiments on five kinds of rocks were carried out. The results showed that the curves of energy evolution exhibited obvious stages and there were significantly different weakening degrees for different rock materials embodied by the decreasing degrees of the ratios of elastic strain energy to dissipated strain energy at the weakening stage. Then, the energy preservation index was further formulated based on the decreasing ratio. Furthermore, by analyzing the acoustic emission activities at the failure stage and failure modes of the five rock materials, the rockburst potential was analyzed according to the energy preservation index.