Figure 2.

The concept of the multi-layer shear model used in the lab experiment. (a) A part of the soil cut out from an infinitely long slope surface layer. The horizontal direction force can be expressed by $\tan \theta$ times the weight of the soil. (b) The force ratio is the same as it turned to the horizontal direction. (c) The 1 m model is divided into the multi-layer model, the horizontal force is loaded on every layer, and every layer can undergo shear deformation independently.