A COUPLED VISCOELASTIC DAMAGE MODEL APPLIED TO SALT ROCK MECHANICS

Resumo

This work describes the application of a viscoelastic damage formulation to the
preliminary study of one-dimensional finite element (FE) modeling of salt caverns structural
behavior. The evaluation of damage in salt rocks is important due the stress relief caused by the
cavern dissolution that generates a large strain energy. If this energy is not reduced, it can lead to
instabilities, and the collapse of the cavern walls. The proposed methodology is divided in two main
steps: a) incorporation of a damage model to one-dimensional analysis of elastic and viscoelastic
materials considering analytical and numerical FE approach, aiming to acquire sensitivity on the
studied problem; b) application of the referred model to the simplified evaluation of salt caverns,
addressing strain levels, damage accumulation due to cyclic load induced by temperature and
pressure variation, and the closure of such caverns. It is expected that this preliminary study allows
the evaluation of the damage modeling influence on the behavior of caverns open in salt domes
under cyclic loading, addressing the rupture mechanisms of these rocks.