Improved matter-element extension model and its application to prediction of rockburst intensity

Based on the improved matter-element extension theory, an improved matter-element extension model used to predict the rockburst intensity was established. Firstly, the main factors of rockburst intensity, such as the maximum tangential stress of the cavern wall σ_θ, uniaxial compressive strength σ_c, uniaxial tensile strength σ_t, and the elastic energy index of rock W_et, were taken into account in the analysis. Three factors, σ_θ/σ_c, σ_c/σ_t and W_et were defined as the criterion indices for rockburst intensity prediction in the proposed model. Secondly, the classification standards of rockburst intensity were confirmed. In order to remedy the defect of the correlation function which may exceed the controlled field, the rockburst intensity classification standards were normalized. And then, based on the game theory, the synthetic weight values of eigenvalue were determined by integrating the objective-dynamic weight and subjective-static weight, solving problems occurred in traditional matter-element extension assessment method like indicator weight only depends on eigenvalue, ignoring the significance of feature. Lastly, the rockburst intensity level (RIL) was predicted by the maximum incidence degree criterion, then are improved matter-element extension model used to predict the rockburst intensity was proposed. 20 cases of the engineering project examples of the domestic and foreign were analyzed by using the proposed model to study the effectiveness and practicality of the model. The results show that the prediction results agrees well with the practical situations, and have higher accuracy compared with the results of the traditional matter-element extension method and the fuzzy mathematics comprehensive evaluation method.