Uniaxial creep characteristics and constitutive model of arkose sandstone with different moisture contents under repeated freeze thaw cycles

To investigate the creep characteristics of water-containing slope rocks in high-cold regions, this study conducted indoor physical and mechanical tests on arkose sandstone specimens, with moisture content and freeze-thaw cycle number as test variables. The test results indicate that under the same stress level, increasing moisture content and freeze-thaw cycle number lead to three key trends: (1) increased instantaneous creep strain of arkose sandstone specimens; (2) decreased long-term creep strength; and (3) intensified material damage. Based on the test data, this study developed and verified a modified Nishihara creep model that incorporates the coupled damage effect of moisture content and freeze-thaw cycle number. This study provides a theoretical basis for predicting the long-term creep behavior of arkose sandstone in water-containing slopes of high-cold regions and preventing slope disasters in open-pit mines.