Correlation between the rockburst proneness and friction characteristics of rock materials and a new method for rockburst proneness prediction: Field demonstration

Prediction of the rockburst proneness of rock in the field is an important problem in rockburst research. In this paper, the analytical relationship between the strength ratio (the ratio of the unconfined compressive strength to the ultimate cutting strength) of rock and the friction angle is presented. A new perspective is presented for rockburst proneness considering the strength ratio and friction characteristics of rock materials. The relationships between the residual elastic energy index (the difference between the peak elastic energy density and failure energy density of the postpeak stage) and the strength ratio and friction coefficient are established to determine the rockburst proneness of rock materials. The linear relationship between the strength ratio and residual elastic energy index is obtained. A novel method is proposed to easily predict the rockburst proneness of rock materials in the field. The rockburst proneness values predicted from the proposed method for six types of rock are consistent with those obtained in the laboratory. This result shows the correlation between the rockburst proneness and friction characteristics of rock materials. The variation in the contact friction angle is similar to the variation in the residual elastic energy index along the borehole. This method is successfully applied to predict the rockburst proneness of the surrounding rock of four tunnel sections.