Abstract
For the disposal of high-level radio active waste, repository in deep underground has been considered. To design deep underground structure without any experience, it is necessary to employ a numerical method that can reproduce the governing phenomenon. In this study, MBC (micromechanics-based continuum model) that can reproduce sliding and opening of joints due to stress relaxation during an excavation is adopted, and a new design method is proposed. After comparing analytical results with measured convergence data and determining the critical value of maximum shear strain, the trial design is conducted. It is shown that a lining thickness is determined for different values of joint spacing and tunnel depth.
