Study of the Nonlinear Mathematical Model for Triaxial Creep of Frozen Soil

The triaxial creep tests on laboratory-prepared frozen clay specimens are carried out with MTS-810 hydraulic servo material test machine,and then creep curves of frozen clay under complex stress state are obtained.The results show that the creep deformation of frozen soil has strong temperature sensitivity;the higher the temperature is,the stronger the temperature sensitivity is;at a same temperature,the larger the load is,the bigger the deformation is.Using relevant theory,the nonlinear mathematical model of triaxial creep of frozen clay under complex stress state is derived.Then equation's parameters of the model are obtained through fitting function of MATLAB software.There is a tight relationship between the model parameters and temperature.Thus a mathematical expression between the two is established.The fitting accuracies between the simulated curves and the experimental curves are high.The established mathematical model can accurately describe the creep law of frozen soil,and will provide effective theory for predicting the deformation in actual frozen soil engineering.