The Influence Of Loading Way To Deformation Characteristics Of Frozen Clay

In order to get the impact on the deformation characteristics of frozen clay of the freezing temperature, moisture content and constitutive property, the conventional uniaxial test of frozen clay is carried on firstly. Aiming at the end effect in routine experiments and the high project cost by large diameter soil sampler and in view of the terrible sample quality with small diameter soil sampler, the new way of loading is adopted respectively. The impact on the deformation characteristics of frozen clay by the new way of loading is obtained under the freezing temperature, moisture content and constitutive property as well. Through summary analysis of the results it can be seen that the uniaxial compressive strength in flexible loading way is slightly higher than that in reducing end face constraint loading ways, however, the elastic modulus under flexible loading way is smaller than that in reducing end face constraint loading ways, and the difference is more obvious with the decrease of temperature. The uniaxial compressive strength of conventional uniaxial test is slightly smaller than that in reducing end face constraint loading ways, and the difference of elastic modulus is more obvious. The failure characteristics of frozen remolded soil generally manifests itself as central drum shape feature in conventional test, however, using reducing end face effect loading ways, the sample destruction was obvious compressed and became short and thick without central bulge. The result of intensity of press-in test with using cone head load is better than the round head load test results. Under the condition of the same moisture content and freezing temperature, the test force of conventional test is bigger than the intensity of press-in test. For intensity of press-in test, confining conditions or not the result are quite different the experimental results showed that the results of intensity of press-in test with unconfined conditions is smaller. And the difference with the increase of moisture content and lower freezing temperature increases. So removing mould for the remolded soil in the process of maintenance and test have a great influence on the test results.The damage process of frozen clay under the load show that the strain threshold value is less affected by temperature. Take as the strain threshold value, the stress threshold value can be expressed as0.336-0.2T. Through the analysis of the damage of clay stiffness and strength degradation, the different expression forms of damage evolution equation of clay are obtained, and the influence factors of two kinds of damage evolution equation reflects is not the same. The stiffness of damage evolution equation contains plastic strain elements only, but the intensity of the damage evolution equation is not only contains plastic strain but also contains freezing temperature change, and influence law by temperature changes is consistent with experimental results. Under the condition of simple loading, both forms can be used the exponential function as to description, the only differences between the two forms is the parameter b. Harden type stress-strain relationship of frozen clay can be described by the linear elastic constitutive model which contain the damage variables. The initial elastic modulus of clay increases with the lower of the temperature.