Seismic analysis of the rock mass classification in the Q-system

• We propose a new equation for seismic analysis of the rock mass classification.
• New equation provides the effects of seismic behavior in Q-system.
• Seismic effect simulates using numerical analysis and empirical results.
• New equation is based on graphs derived from numerical analysis.
• Examples indicate the reasonable and acceptable results.

Empirical, numerical and analytical methods are regarded as different tools for design of tunnel. Empirical methods have been established based on the experience resulted from different projects. Based on the recorded information, underground structures enjoy a higher level of safety against dynamic waves compared to surface structures. Previously, the seismic design of underground structures has received less attention than that of surface structures, while designing underground structures without considering seismic loads would result in an unsafe structure. In rock mass classification, despite considering various parameters for designing underground structures, the seismic parameter has been disregarded or has been expressed in a very general manner. Taking into account the seismic effect in rock mass classification is a relatively new topic which has been addressed in this paper. Moreover, it has been attempted to investigate the seismic effect in the Q-system using numerical analysis. The results obtained from numerical simulations are compared and counterbalanced with the results of Q-system. After comparing and analyzing the results, a relationship has been proposed for the effects of seismic behavior in Q-system. The solved examples give reasonable and acceptable results.