Flow only analysis and fully coupled flow deformation calculation type

Question

Hi, 
 according to the manual the calculation type Flow only can be only used to perform a groundwater flow analysis in both un/saturated soils and no stresses shall be obtained from such an analysis, while on the other hand the calculation type Plastic is used to perform a deformation analysis. 
 Does the Fully coupled flow deformation combine both types of calculation together? If the answer is yes, can we come to the conclusion that a Fully coupled flow deformation analysis gives the same seepage path/line obtained from a groundwater flow analysis ? 
 If the answer is no, is there anyway to obtain stress values out of a flow analysis or is ist possible to run a plastic analysis following a groundwater flow analysis? 
 
 Thank you in advance

Stefanos Papavasileiou · Answer

Dear Ahmad, 
 You are correct about the Flow only option - it allows for performing a steady-state groundwater flow and transient groundwater flow (not for Initial phase) analysis. In this case, there is no stress or deformation analysis taking place. 
 A plastic analysis involves a stress analysis and can include the presence of water via a phreatic or steady-state groundwater flow pore pressure calculation type. 
 The fully coupled flow-deformation analysis, as the name already tells us, considers the simultaneous development of deformation and pore pressures in saturated and partially saturated soils as a result of time-dependent changes in the water conditions. In principle, the results will be similar but keep in mind that the resulting deformation can have an influence on this. 
 Note that it is not possible to start with a Flow only and then switch to deformation analysis (including fully coupled flow-deformation). However, you can consider running a deformation analysis from the beginning and when needed include either a Plastic with steady-state groundwater flow pore pressure calculation or a fully coupled flow-deformation analysis.