The active pore pressures in interfaces in PLAXIS 3D2013.00 are not correct: the value for the active pore pressure is divided incorrectly by a factor 100. The reason is that the active pore pressures in the Output program are multiplied by the effective saturation as a ratio, while a percentage value was expected.Additionally this results in incorrect total stresses, since this is calculated in the Output program by summing the effective stresses and active pore pressures.
Note that the calculation results are still correct! This is an issue in the presentation of the interface stresses the PLAXIS 3D 2013.00 Output program only!
To calculate the correct value for the active pore pressure, you can manually multiply the results by a factor of 100. To determine the correct total stress in the interface, sum the effective stress and this corrected active pore pressure.
This issue has been fixed in the release of PLAXIS 3D 2013.01