Experimental investigation of accumulation deformation properties of frozen silt clay under different cyclic stress-paths

Abstract

The long-term serviceability of infrastructures in cold regions is inevitably affected by such dynamic loads in practical works as earthquake loading and vehicle loading. In order to study the deformation characteristics of frozen soil under the seismic loading, namely P-waves and S-waves coupled action, different cyclic stress paths were simulated by using triaxial testing equipment with bidirectional cyclic loading function. The results indicate that the cyclic shear stress was main factor in the development of permanent axial strain of frozen sample, while the cyclic normal stress had limited impact. In the case of same stress path, the clockwise rotational-direction of the cyclic stress path is more conducive to the accumulation of the axial permanent strain. In addition, the residual strain generated is greater in the loading process than in the unloading one under the similar conditions. The synchronous vibration of normal stress and shear stress makes the elastic strain maintain larger value than the reverse synchronous vibration, but the asynchronous vibration makes the residual strain keep larger than the synchronous vibration under the condition of the same number of loading cycle.