When a geometry model is created in the Input program it is suggested that the different
input items are selected in the order given by the second tool bar (from left to right). In
principle, first draw the geometry contour, then add the soil layers, then structural
objects, then construction layers, then boundary conditions and then loadings. Using this
procedure, the second tool bar acts as a guide through the Input program and ensures
that all necessary input items are dealt with. Of course, not all input options are
generally required for any particular analysis. For example, some structural objects or
loading types might not be used when only soil loading is considered, or the generation
of water pressures may be omitted if the situation is completely dry, or the initial stress
generation may be omitted if the initial stress field is calculated by means of gravity
loading. Nevertheless, by following the tool bar the user is reminded of the various input
items and will select the ones that are of interest. PLAXIS will also give warning
messages if some necessary input has not been specified. When changing an existing
model, it is important to realise that the finite element mesh and, if applicable, the initial
conditions must be regenerated to make them in agreement with the updated model. This
is also checked by PLAXIS. On following these procedures the user can be confident that
a consistent finite element model is obtained.