## 3 Laboratory Model Tests  
### Experimental Set-Up  
The vertical retaining wall of reinforced soil was constructed and loaded at laboratory conditions. The experiment was carried out in a rigid test box with inside dimensions of 100 cm (height) \(\times\) 37 cm (width) \(\times\) 180 cm (length). The front and back walls of the box were made of glass (both 2 cm thick) in order to observe deformations of the model during loading. These walls were not lubricated, ensuring that good images of the soil deformations could be captured. The RS model consisted of 10 layers of sand with fabric reinforcement laid between them. The model was characterized by the following dimensions: 50 cm (height) \(\times\) 60 cm (length) \(\times\) 37 cm (width). The model of the footing used for the test was made of a 2.5 cm thick rigid steel plate with a rough base of 29 cm \(\times\) 37 cm. The length of the plate was equal to the width of the tank to maintain plane strain conditions. The footing was connected to a vertical pull-out loading arm with a load cell, which in turn was  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Reference** & **Code** & **Facing Model** & **Reinforcing Model** & **Soil Model** & **Soil/Reinforcement Interfaces** & **Soil/Wall Interfaces** \\ \hline
[43] & FLAC & linear elastic & elastic-plastic & Mohr-Coulomb with & & **Inters** & \\  & element & (two-node cable & hyperbolic & grout material with & \\  & & element) & element) & stress–strain model & zero thickness & slip element \\ \hline
[90] & Abaqus & linear elastic manner; & linear elastic manner; & three-node truss & & & \\  & eight-node plane & eight-node plane & elements & isignificant & Mohr-Coulomb & & \\  & strain elements & compressive or & & failure criterion and & zero thickness & slip element \\  & & bending strength & & non-associated flow & & \\ \hline
[91] & PLAXIS & linear elastic element & linear elastic & stress-dependent & & \\  & & geogrid element & hyperbolic & grout material with & & \\  & & geogrid element & Hardening Soil & zero thickness & slip element \\  & & & (HS) model & & & \\ \hline
[88] & FLAC & linear elastic element & linearly elastic-plastic & Cap-Yield (CY) & linearly & \\  & & strip element & soil model & plastic model with & & plastic model with \\  & & & & Mohr–Coulomb & & \\  & & & elastoplastic & creep model & & \\  & & elastic element & viscoplastic & modified with & & \\  & & bouncing surface & model & & \\  & & model & & hysteric behavior & & \\ \hline
[89] & FLAC3D & linearly elastic element & three-node shell & & Mohr–Coulomb with & & \\  & & elastic element & isotropic linear-elastic & hyperbolic & & \\  & & material & stress–strain model & & \\ \hline
[93] & PLAXIS & three-node beam & & & Interface elements & \\  & elements with flexural & & & with three pairs of & \\  & rigidity and & & & & nodes, characterized & \\  & normal stiffness & & & by zero & \\  & & & & thickness & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Typical assumptions in the numerical modeling of the behavior of RS walls.  
connected to an electro-mechanical actuator. The footing displacement was measured by displacement transducers. Five horizontal displacement transducers were located along the height of the RS model's facing in order to measure lateral displacements during loading. A schematic view of the test configuration is presented in Figure 3.