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Abstract Triaxial creep and elastic aftereffect tests to the sandstone specimens from the Three Gorges reservoir area were carried out with the creep testing machine of rock. The creep and elastic aftereffect deformation curves under different pressures were acquired. The rock specimens exhibited the time-dependent deformation characteristics. The creep curves had the typical three stages of rock creep. The magnitude and the rate of the time-dependent deformations gradually increased with the increasing of the pressure. The creep and the irreversible deformation were similar. The creep model of Burgers and the constitutive equation of the elastic aftereffect under the three-dimensional stress state were deduced. The parameters of the triaxial creep and elastic aftereffect models were obtained from the test data calculated with an optimized algorithm. The time-dependent parameters were nonlinearly reduced gradually with the increase of the stress levels. When the sandstone was in the stage of creep，the parameter of viscosity reflected the steady state of creep deformation of rock specimen. When the sandstone was in the stage of aftereffect，the parameter of viscosity described the variation of irreversible deformation after creeping.
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2015, Vol. 34 
