Abstract:

Rockburst is a common geological hazard encountered during excavation in high stress area. It happens suddenly and sometimes may bring devastating consequence. Therefore, prediction of rockburst intensity is always the emphasis in rockburst research. Based on the basic theory of gray relation projection method, main factors that effect the occurrence of rockburst and the existing evaluation index system of rockburst are comprehensive analyzed. Four indices including the ratio of the maximum tangential stress to uniaxial compressive strength σθ/σc, the brittleness coefficient of rock (the ratio of uniaxial compressive strength to uniaxial tensile strength) σc/σt, the elastic energy index of rock Wet and the integrality coefficient of rock Kv are selected as evaluation indices. By adopting entropy theory to determine the weighting coefficient of each evaluation index and gray relation projection method to calculate and grade the projection values, rockburst intensity is predicted. Several typical engineering projects at home and abroad are taken to validate the feasibility and applicability of this method, and the results are compared with the prediction results of the entropy and normal cloud model, the RS-TOPSIS model and practical situation. The research result shows that the gray relation projection method used in rockburst intensity prediction is with high accuracy and easy to understand and use, which has good prospect in engineering application.

Key words: rockburst prediction, intensity classification, entropy, gray relation projection method