At the limits of the calculation section, the force and displacement boundary conditions must be defined for the cut-off boundary surfaces in order to determine the influence of the outer areas. For this, components of the displacements of the boundary surfaces are usually set to zero.
The figure below shows the support conditions preset by default for the boundary surfaces of the soil volume to be analyzed in RFEM 6. These can be edited flexibly, if necessary.
The displacement boundary conditions in the figure are defined as follows:
- (1) - Base area: fixed support with u x = u y = u z = 0
- (2) - Surface: free edge area
- (3) - boundary surface in the xz-plane: Plain support with u y = 0, u x ≠ 0 & u z 0
- (4) - boundary surface in the yz-plane: Plain support with u x = 0, u y ≠ 0 & u z 0