(1. Institute of Geotechnical Engineering，Xi?an University of Technology，Xi?an，Shaanxi 710048，China；2. Xi?an Research Institute，CCTEG，Xi?an Shaanxi 710077，China；3. State Key Laboratory of Frozen Soil Engineering，Northwest Institute of
Eco-environment and Resources，Chinese Academy of Sciences，Lanzhou，Gansu 730000，China；4. School of Civil Engineering，
Lanzhou Jiaotong University，Lanzhou，Gansu 730070，China)
Abstract：The slopes of open-pit mine are always in freezing- thawing environment in permafrost region，and the surface rock of slopes is weathering during the freezing- thawing cycles. The cyclic freezing-thawing tests on the saturated sandstone from the mining area in Muli were completed in laboratory in order to understand the physical and mechanical characteristics of saturated rock in freezing-thawing cycles. The degradation model for the saturated rock was studied. The micro-fracture rate increases gradually with increasing the freezing-thawing cycles，but the uniaxial and triaxial compression strengthes and other physical parameters decreases with the number of the freezing-thawing cycles. The micro-fracture propagation factor was suggested according to the micro-fracture change in the freezing-thawing cycles. The theoretical damage model and constitutive relations of rock strength were established using the micro-fracture propagation factor. The proposed model explained quantitatively the damage of the saturated rock due to freezing-thawing. The theoretical strength calculated with the damage model matched well with the test results. The composite stress generated due to water transformation to ice exceeded the strength of rock and drove the micro- fracture to expand.
徐拴海1，2，3，李 宁1，3，4，王晓东2，3，许刚刚2，袁克阔2，田延哲2，王莉平1. 露天煤矿冻岩边坡饱和砂岩冻融损伤试验与劣化模型研究[J]. 岩石力学与工程学报, 2016, 35(12): 2561-2571.
XU Shuanhai1，2，3，LI Ning1，3，4，WANG Xiaodong2，3，XU Ganggang2，YUAN Kekuo2，TIAN Yanzhe2，WANG Liping1. Damage test and degradation model of saturated sandstone due to cyclic freezing and thawing of rock slopes of open-pit coal mine. , 2016, 35(12): 2561-2571.
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2016, Vol. 35 
