In order to study physical and mechanical properties of saturated sandstone under freeze-thaw cycles in the alpine region,uniaxial compression tests under four different freeze-thaw cycles of 0 times,20 times,40 times and 60 times were designed.And then based on the test results,this article analyzes the effect of freeze-thaw cycles on quality,deformation and the other mechanical properties such as strength.According to the results,with the increasing of freezing-thawing times,the mass of saturated sandstone increased continuously.After 40 freezing-thawing times,the mass of saturated sandstone tended to be stable.The stress-strain curve of sandstone can be divided into four stages.The peak strength and elastic modulus decrease linearly with the increasing of freezing-thawing times.Finally,the constitutive model of a neural network with a hidden layer is established with strain and freeze-thaw times as input layer and stress as output layer.By comparing and analyzing the freeze-thaw test results of 60 times,the model is proved to have good applicability.
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