The retaining wall is assumed to be rigid. The horizontal movement can therefore be applied directly on the soil via Dirichlet boundary conditions.

The retaining wall on both sides of the soil is assumed to be frictionless; therefore, only a fixed horizontal movement is necessary.

The bottom movement of the soil structure is supported via rolling boundary conditions.

In the first load step, an in situ earth-pressure state is generated by applying a gravitational acceleration of on the soil in the vertical direction.

In a following load step, an active earth-pressure state is generated by horizontally moving the soil nodes of the left boundary away from the soil using a specified displacement of u_x = -0.075 m.

Alternatively, a passive earth-pressure state is produced by horizontally moving the soil nodes of the left boundary towards the soil using a specified maximum displacement of u_x = 0.5 m.