The evaluation and judgment of surrounding rock stability after deep roadway excavation is of great significance for roadway support design and prediction of surrounding rock failure characteristics. In order to solve this problem, the advanced strain softening model based on Hoek Brown criterion developed by Itasca was used to simulate the mechanical response of surrounding rock in deep roadway. Firstly, the theoretical background and characteristics in analyzing the post peak softening characteristics of rock mass of the advanced strain softening model are introduced; Secondly, the key parameters of the model (strength parameter, modulus softening parameter, dilatancy parameter and brittle ductile plastic transition parameter) are studied. The simulation results show that the modulus softening effect and dilatancy effect of rock mass must be considered for rock mass with poor quality and strong brittleness, but not for rock mass with general quality and good quality and rock mass with less brittleness; at the same time, based on the previous analysis conclusion, with the help of analytic hierarchy process, a comprehensive index evaluation method for evaluating the stability of surrounding rock in deep roadway is proposed, which takes into account the weight differences of various factors and considers comprehensively and reasonably; Then, based on a specific engineering example, the advanced strain softening model and the conventional strain softening model (based on Hoek Brown criterion) are compared and analyzed by using the comprehensive index evaluation method. The results show that the comprehensive index conclusion obtained by the advanced strain softening model is most consistent with the field measurement results, among them, the deviation of the conventional strain softening model is 161.74%, indicating poor reliability; The IMASS model has a deviation of 26.49% and high reliability. It further shows that the advanced strain softening model based on Hoek Brown criterion is more suitable for the study of the stability characteristics of surrounding rock in deep roadway. The comprehensive index evaluation method proposed by AHP has guiding significance for the stability evaluation and support design of surrounding rock in actual underground engineering. Finally, a brief summary and analysis were conducted on the shortcomings and prospects of this study.
Wang et al. (Tue,) studied this question.