IMPROVEMENT OF LEMAITRE'S CREEP LAW TO ASSESS THE SALT MECHANICAL BEHAVIOR FOR A LARGE RANGE OF THE DEVIATORIC STRESS

摘要

This paper describes the investigations made to reproduce with the strain-hardening transient Lemaitre's law the creep of a rock salt tested in laboratory under different levels of the deviatoric stress. The results obtained showed that, when fitted on a given range of the mechanical loading, the law underestimates the deformational response of the sample for the opposite range of loading. An improvement was brought to the Lemaitre's law to integrate the contribution of both low and high deviatoric stresses. This new development was implemented into a numerical software in order to simulate the impact of deviatoric stresses on the thermo-mechanical behavior of salt caverns.