关键词: 非饱和土, 蠕变, 基质吸力, 应力水平, 滑坡

Abstract:

The instability process of most landslides is non-saturated creep essentially. On the basis of research results by Singh-Mitchell, we study the relationship between creep deformation and time variable under low stress levels. The creep process can be divided into 3 stages of decayed creep, steady creep and accelerated creep. An unsaturated creep model that reflects the relation of stress-suction-strain-time is established, in which the matrix suction is considered as a new variable of the model. According to the unsaturated triaxial creep test on landslide soil collected at Qianjiangping landslide, Three Gorges Reservoir area, the model parameters are calculated, and the model are further corrected according to the relationship between the parametersλ1、λ2and stress level, and the relation between B、β_DR and time. The model is validated by experimental data and the results indicate that the model could forecast the creep characteristics of landslide soil.

Key words: unsaturated soil, creep, matrix suction, stress level