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The dynamic retain and strength of frozen silt under long-term dynamic loading are studied based on creep tests.Three groups of tests are performed (Groups Ⅰ,Ⅱ,and Ⅲ).The initial deviator stresses of Groups Ⅰ and Ⅱ are same and the dynamic stress amplitude of Group Ⅱ is twice as that of Group Ⅰ.The minimum value of dynamic stress in Group Ⅲ is near zero and its dynamic stress amplitude is larger than those of Groups Ⅰ and Ⅱ.In tests of all three groups there are similar change trends of accumulative strain,but with different values.The accumulative strain curves consist of three stages,namely,the initial stage,the steady stage,and the gradual flow stage.In the tests of Groups Ⅰ and Ⅱ,during the initial stage with vibration times less than 50 loops the strain amplitude decreased with the increase of vibration times and then basically remained constant,fluctuating in a very small range.For the tests of Group Ⅲ,during the initial and steady stages the strain amplitude decreased with the increase of vibration times,and then increased rapidly in the gradual flow stage.The dynamic strength of frozen silt decreases and trends to terminal dynamic strength as the vibration times of loading increase.