Theoretical verification of the rationality of strain energy storage index as rockburst criterion based on linear energy storage law

Abstract

The rationality of using strain energy storage index (Wet) for evaluating rockburst proneness was theoretically verified based on linear energy storage (LES) law in this study. The LES law is defined as the linear relationship between the elastic strain energy stored inside the solid material and the input strain energy during loading. It is used to determine the elastic strain energy and dissipated strain energy of rock specimens at various loading/unloading stress levels. The results showed that the Wet value obtained from experiments was close to the corresponding theoretical one from the LES law. Furthermore, with an increase in the loading/unloading stress level, the ratio of elastic strain energy to dissipated strain energy converged to the peak-strength strain energy storage index (Wetp). This index is stable and can better reflect the relative magnitudes of the stored energy and the dissipated energy of rocks at the whole pre-peak stage than the strain energy storage index. The peak-strength strain energy storage index can replace the conventional strain energy storage index as a new index for evaluating rockburst proneness.

Keywords

• Rockburst criterion
• Strain energy storage index
• Linear energy storage (LES) law
• Peak-strength strain energy storage index