Steady-State Creep of Rock Salt: Improved Approaches for Lab Determination and Modelling

摘要: Actual problems in geotechnical design, e.g., of underground openings for radioactive waste repositories or high-pressure gas storages, require sophisticated constitutive models and consistent parameters rock salt that facilitate reliable prognosis stress-dependent deformation associated damage. Predictions have to comprise the active mining phase with open excavations as well long-term development backfilled mine repository. While convergence-induced damage occurs mostly vicinity openings, behaviour system is dominated by damage-free steady-state creep. However, because experiments time necessary reach truly stationary creep rates can range from few days years, depending mainly on temperature stress, an innovative but simple testing approach suggested obtain more results: A series multi-step tests loading unloading cycles allows a estimate rate reasonable time. For modelling, we use advanced strain-hardening Gunther–Salzer, which comprehensively describes all relevant properties such damage-induced failure within scope unified ansatz. The capability combination improved procedures accompanied modelling demonstrated recalculating at different conditions. Thus extrapolations in-situ ( $$10^{-9}$$ $$10^{-13}$$  s $$^{-1}$$ ) become possible.