Limit equilibrium analysis method for loess slopes considering spatial-temporal evolution laws of parameters

The research on the slope stability analysis method considering the special mechanical properties of the loess is of great significance to the implementation of the national strategy of "Western Development" and the initiative of "Belt and Road". Based on the research idea of the sequential coupling of seepage-softening-stability analysis, the stability of the loess slope under rising of the ground water level is studied. Firstly, the seepage analysis of the loess slope under rising of the ground water level is carried out by using the unsaturated unsteady seepage analysis theory. Secondly, based on the calculated results of the seepage analysis, the spatial distributions of strength parameters are dynamically updated by the water-induced structural deterioration equation. Thirdly, based on the spatial-temporal distribution laws of total unit weight, cohesion, internal friction angle and pore pressure, the limit equilibrium analysis method for the loess slope considering spatial-temporal evolution laws of parameters is proposed. Finally, taking a loess slope in Bailuyuan of Xi'an city in China as an example, the stability of the loess slope is comparatively analyzed by using the Spencer’s method and the M-P’s method considering spatial-temporal distribution laws of parameters. Meanwhile, the comparative analysis of the calculated results by using the proposed method with the on-site investigation is done, thus the reasonability and reliability of the proposed method are verified.