Rock bursts analysis of parallel tunnels using numerical modelling /

Abstract

One of the essential components of the underground excavation design process, which directly influences the performance and stability of underground constructions, is knowledge of the in-situ and mining-induced stress. Knowing the magnitudes and directions of these stresses can help determine suitable shapes and orientations for tunnels (drifts) and stopes. In addition, knowing the stress regime in the rock mass can be used to predict the type of rock failure that may occur in the future and identify potential rockbursting zones. In this research, the main objective is to develop an engineering methodology to estimate the mining-induced stress regimes in the host rock and orebody using the finite element analysis method. A potential hydro-electric project site is used to illustrate the estimation procedure and to implement the proposed methodology. To reach the objectives of this research, 2-dimensional finite element models of the project site were developed. These finite element analysis models were used to determine the mining-induced stress regimes at the potential hydro-electric project site. The results of FE analysis were used in combination with tangential stress criterion for rock burst assessment in parallel tunnels. The main contributions of this study include developing and implementing an engineering methodology for estimating mining-induced stresses, providing a better understanding of the stress distribution regime around a tunnel and investigating the role of overburden thickness and excavation sequence on mining-induced stress fields