Experimental Study On Thermodynamic Properties And Creep Property Of Artifical Frozen Soil Under Different Freezing Temperature

In recent years, the artificial freezing method is widely used in various fields. It is an integral part of engineering applications to doing the research on permafrost formed by artificial freezing method. Considering the importance of artificial freezing method in practical engineering applications, In this paper, the experimental research is the main content. We can through field sampling and process into the test sample according to the test required, then carry out the research about the physical and mechanical properties of artificial frozen clay and creep property, hoping that it can be able to provide theoretical basis for practical engineering application and technical assistance.Accordance with the requirements of the topic research, This paper has carried on a determination of conventional geotechnical experiments and thermal physical property indexes to frozen clay sample; Then doing the determination of the mechanics index of frozen clay in uniaxial tester and W3Z WDT-100type-200triaxial testing machine developed by anhui university of science and technology. they are mainly the uniaxial compressive strength test and triaxial shear strength test. According to the results of uniaxial compressive strength test, getting the analysis and calculation results of the elastic modulus and poisson’s ratio and establish the stress-strain relationship curve. Based on the triaxial shear strength of frozen clay, When the freezing temperature keeps a certain value, The shear strength of artificial frozen clay increases with the increasing of confining pressure and show a linear increasing trend; According to the stress-strain relationship to drow the isochronous stress-strain relationship curve, When the deviatoric stress level is low, stress-strain relationship of artificial frozen clay is linear, when the deviatoric stress level is higher, the stress-strain relationship is curved. Using the modified Cambridge model to be used as artificial frozen clay strain hardening elastoplastic model, can well reflect the relationship between the principal stress and axial strain, but has yet to be further on shear properties of correction.Based on the triaxial shear strength test of frozen clay, getting the values of the shear strength of frozen clay, and drawing out the strength of frozen clay envelope. Through the uniaxial compression creep experiment and triaxial creep experiment of frozen clay knowing that:the uniaxial creep test curve and the triaxial creep test curve are similar, which marks a transition from simple stress state to a complex stress states about the research of mutation characteristics of frozen clay. Under the effect of low constant force, the creep deformation of artificial frozen clay is the characteristics of two phases of deceleration creep and steady creep.The analysis base on the results of uniaxial compression creep test of frozen clay, combine with the power function equation recommended by the C.C.Rove, we can establish a constitutive equation on stress, strain, temperature and time of interaction of frozen clay in simple stress conditions. According to the analysis of artificial frozen clay in triaxial creep experiment, The average rate of creep deformation decreases with the increasing of confining pressure, but increasing with the increasing of deviator stress.