Are stress and groundwater analyses separate in RS2, or is the effect of water on field stress included?

RS2 has two analysis options for Solid-Fluid Interaction:

  1. Uncoupled
  2. Coupled (Biot Theory)

The following is taken from the Online Help:

Uncoupled Analysis

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.