Three-dimensional modelling and sensitivity analysis for the stability assessment of deep underground repository

For the mechanical stability assessment of underground high-level waste repository, computer simulations using the three-dimensional simulation code, FLAC3D, were carried out and important parameters including stress ratio, depth, tunnel size, joint space, and joint properties were chosen from the sensitivity analysis of the results. The main effect as well as the interaction effect between the important parameters could be analyzed using fractional factorial design. In order to analyze the stability of deposition tunnel and deposition hole in discontinuous rock mass, different modellings were performed under different conditions using 3DEC. From this, the influence of joint distribution and properties, rock properties, and stress ratio could be determined