To research the creep behavior of salt rock, the uniaxial and triaxial creep experiments
were carried out under different deviatoric stresses and same confining pressure or different confining
pressures and same deviatoric stress. The experiment results showed that the analysis on the creep
damage of salt rock should consider the influence of confining pressure and deviatoric stress. By
introducing the damage variable to the Norton Power law of salt rock, a new constitutive law of salt
rock was presented. The damage equivalent stress was the function of the confining pressure and the
deviatoric stress in the new constitutive law. The constitutive law can embody the steady creep and
accelerative creep of salt rock, in which the parameters are obtained by simulating the experimental
data of salt rock in some salt mine. The theoretic results are in good agreement with the experimental
results.
The new constitutive law was embedded in the three dimension numerical codes. The natural gas
storage in the salt mine was analyzed by the new constitutive law. The evolvement law of damage
bound and the displacement law around the natural gas storage were studied under the minimal
natural gas storage pressure. The continuous operating time of the natural gas storage was also
analyzed under the pressure. The research conclusions are expected to be applied in the natural gas
storage projects in salt rock layer.