Abstract

Rockburst in tunnels is a threat for both workers and equipment. Therefore, their assessment is of major importance. However, these events are difficult to predict, due to their complexity. Additionally, there is an uncertainty regarding the characteristics of the environment in which the rockburst can occur, and the influence that they can have on the intensity of the event. This work proposes to study the influence of (1) the Young modulus, (2) the Poisson coefficient, (3) the in-situ stresses, and (4) the stress-ratio K, on the strain energy of a potential rockburst. To do so, 3D numerical modelling have been conducted using the FLAC3D code, considering an elastic constitutive model. To characterize the rockburst, the following parameters are assessed: maximum strain energy around and in the front of the tunnel. To validate the results, they are compared to analytical ones obtained considering Lame’s solution. The results between the analytical and numerical approaches were consistent, which allow us to confirm the numerical procedure. Results show that the maximum strain energy is always located around the tunnel and never in the front of the tunnel. Moreover, the in – situ stress is the parameter with the highest impact on the maximum strain energy. The young’s modulus and the stress ratio k present the second highest impact. The Poisson ratio has zero to low impact. Finally, the maximum strain energy is not located at the front of the tunnel but at the countour of the start of the excavation.

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