To study thelong-term creep mechanical properties of surrounding rock in the deep roadwayunder the action of groundwater

a self-developed five-joint rheologicalexperimental system was used to carry out uniaxial compression tests anduniaxial creep tests on sandstone with different water contents (0%

0.8%

1.6%

2.4%

and 3.3%) under water absorption and softening conditions. Someexperimental findings were revealed. The uniaxial compressive strength

elasticmodulus

and creep failure stress of sandstone decrease exponentially withwater content

and the ratio of creep failure stress to uniaxial compressivestrength ranges from 0.76 to 0.84. The attenuation creep time of sandstonedecreases with the increase of water content and increases with the increase ofstress level. The radial strain enters the steady-state creep stage earlierthan the axial strain

and the accelerated creep stage of the radial strainunder the damage stress starts earlier than the axial strain. The long-termstrength of the sandstone is determined based on the steady-state creep ratecurve

and the value of steady creep rate in the radial direction is slightlyless than the axial one

and the long-term strength satisfies a negativeexponential relationship with the water content. The ratio of radial strain toaxial strain in the creep test is defined as

value is independent of water content

and a methodfor determining the long-term strength of rock based on value is proposed. For the sandstone samples used in this study

it canbe considered that accelerated creep failure will occur in a particular periodof time when the ratio surpasses 0.3. As the water content increases

failurepattern of samples gradually change from single inclined plane shear failure toX-shaped conjugate inclined plane shear failure. Theresearch results provide a reliable theoretical basis for long-term stabilityanalysis and early prediction of roadway creep failure under groundwa