RS2 has two analysis options for Solid-Fluid Interaction:
- Coupled (Biot Theory)
The following is taken from the Online Help:
The default analysis is Uncoupled (i.e. changes in pore pressure do not affect deformation and changes in loading or deformation do not affect pore pressure). This is the case for a total stress analysis (i.e. deformation is a result of changes in total stress).
If the Use Effective Stress Analysis checkbox is selected (on the Stress Analysis page of the Project Settings dialog), then deformation is a result of changes in effective stress. This is a partially coupled analysis where changes in pore pressure, and thus effective stress, affect deformation but changes in deformation or loading do not affect pore pressure.
Coupled Analysis (Biot)
For a fully Coupled analysis based on Biot theory, you must first enable Transient Groundwater in Project Settings. Then you can choose the Coupled Solid-Fluid analysis option. This is used for time-dependent consolidation analysis problems, in which changes in pore pressure can affect deformation and changes in loading or deformation can affect pore pressure.