A new creep contact model for frozen soils and its application

To study the bond effect on the creep mechanical properties of frozen soils, a creep contact model for frozen soils is proposed based on the generalized Kelvin body. Tensile and shear strength micro-parameters were introduced to reflect the cementation properties of frozen soils. A subroutine (DLL), called by the particle flow program (PFC3D), was generated using the language C++. Triaxial creep tests were carried out on frozen soils under different axial stress conditions. A comparison of the numerical simulation and laboratory test results showed that the proposed contact model can well reflect the creep mechanical properties of frozen soils. Based on the calibrated model micro-parameters, a series of triaxial creep simulations were carried out to study the effects of the cementation state, confining pressure, and damage state on the creep mechanical properties. The simulation results showed that the cementation state, confining pressure, and damage state have important influences on the creep mechanical properties of frozen soils. The characteristics of the creep curves, number of cracks, and number of force chains with the creep time were thoroughly analyzed. These results can provide a basis for studies on macro-meso creep mechanical properties of frozen soils.