Experimental and theoretical studies on the creep behavior of warm ice-rich frozen sand

摘要

It is recognized experimentally that the creep property of warm ice-rich frozen soils will cause a significant deformation, which affects the stability of infrastructure constructed in permafrost regions. In this paper, the creep behavior of warm ice-rich frozen sand is investigated through a series of experimental data under different stress levels at temperatures of - 1.0 ℃, - 1.5 ℃ and - 2.0 ℃, respectively. The results showed that the creep characteristic of warm ice-rich frozen sand is greatly affected by the stress levels. The creep curves mainly present the decaying and the stable creep stages under low stress levels. However, under high stress levels, once the strain increasing to critical value, the creep strain velocity gradually increases and the specimen quickly happen to destroy. To reproduce the creep process of warm ice-rich frozen sand, a statistical damage constitutive model, in which the Weibull function is employed to describe the random distribution of inner flaw in creep process, is proposed based on the experimental results. The validity of the model is verified by comparing its modeling results with the results of creep tests both under low and high stress levels. It is found that the results predicted by this model agree well with the corresponding experimental data.