Narrow Results

In this study, the effects of freeze–thaw cycles and cyclic impacts on frozen soil were systematically investigated. With an increase in the number of freeze–thaw cycles, the peak stress of frozen soil decreased until a stable state was achieved. Moreover, subjecting frozen soil to an increased number of cyclic impacts led to notable alterations in mechanical characteristics, including peak stress, critical strain and dynamic elasticity modulus. Both the freeze–thaw cycles and cyclic impacts were identified as primary damage mechanisms in understanding frozen soil degradation processes. Damage resulting from these impacts conformed to the Weibull distribution pattern. Damages induced by freeze–thaw cycles, individual impacts and cyclic impacts were integrated into the Zhu–Wang–Tang viscoelastic model (ZWT model). Relying on principles of elastic mechanics, the role of confining pressure on frozen soil was examined and subsequently integrated into an improved ZWT model. To evaluate the model’s effectiveness, its predictions were compared with experimental results.

This paper focuses on the influence of frozen soil on seismic response of a building supported by pile foundation. Firstly, the saturated sand soil is frozen artificially, and then shaking table tests are conducted. Specifically, seismic responses of buildings with different natural frequencies and with different freezing depths of the saturated soil are investigated, respectively. In this study, it is confirmed that for buildings with high rigidity, the effect of interaction becomes smaller when the soil is frozen. Moreover, it is observed that the resonant frequency of frozen ground is closer to the natural frequency of superstructure, and thus the response of the superstructure becomes larger. It is also observed that the bending moment along the pile is remarkably reduced by improving the rigidity of the soil.