NUMERICAL STUDY OF THE BEHAVIOUR FOR ELASTICVISCOPLASTIC ROCK AROUND CIRCULAR GALLERIES

Abstract

The variation of stress during creep convergence of a horizontal circular galleries excavated in rock salt is studied. Examples are given for rock salt by N. Cristescu ([1], [2]). A non-associated elasto-viscoplastic constitutive equation is used to describe both compressibility and/or dilatancy during transient and steady-state creep, as well as evolutive damage possibly leading to failure. An in-house FEM numerical method and iterative method is used for this purpose ([4], [6]). The variation in time of radial convergence of the galleries walls and of the stress state will be illustrated by several figures. The significance of these variations for long-term stability is discussed. Numerical results are obtained using MATLAB ([8], [9]).