Can I model, analyze and design retaining walls in STAAD.Pro ?
One can model retaining walls in STAAD.Pro using solids elements or plate elements. If the objective of the analysis is to get the support reactions, joint displacements, concrete stress etc. then modeling with solid elements can be pursued. However one should keep in mind that although modeling with solid elements can create very accurate models but the meshing options available within STAAD.Pro when it comes to solid modeling is little limited which makes modeling with solids a little more involved compared to modeling with plates. Apart from the difficulty with respect to modeling, using solid elements has another disadvantage which is that you cannot get moments from the analysis as solids do not have rotational dofs at the nodes.
So if the objective of the analysis is to get the moments and to design reinforcements, in addition to the other output mentioned in the paragraph above, modeling with plate elements would be the way to go. In general if the cross section of the wall is tapered, modeling of it can be simplified if one uses an average uniform thickness rather than a varying thickness to simulate the trapezoidal cross section. One can specify plates of varying thickness too but only the modeling would be more involved as in that case, at every increment along the height of the wall, one would need to specify the thickness. The toe, heel and counterforts could be modeled with plate elements as well. Loads can be applied using the hydrostatic option or the pressure load on full plates option available within Plate Loads. Although STAAD.Pro does not have a specific design for retaining walls but based on the moments calculated from the FE Analysis, it can calculate reinforcement requirement as per various concrete design codes like the ACI 318, IS 456, CAN/CSA A23.3 etc.