Problem description

In PLAXIS Output, you can visualise the phreatic level by selecting the option by selecting the menu option Geometry > Phreatic level.

In PLAXIS 3D Output 2023.2, the visualisation of the phreatic level outside a soil/rock volume is incorrect, as shown in the example below.

Figure 1. Definition of phreatic level in PLAXIS Input 

Figure 2. Incorrect visualisation of external phreatic level in PLAXIS Output

The calculation results are correctly computed since the pore pressures and stress distribution are not affected by the incorrect visualisation of the phreatic level.

The issue is only related to the way the phreatic level is displayed when being outside a soil/rock volume.

Workaround

This issue is now solved in PLAXIS 3D 2023.2.1. Please update to this version when encountering this issue in PLAXIS 3D 2023.2.0

In PLAXIS 3D 2023.2.0, you can only hide the phreatic level using the menu option under Geometry > Phreatic level and rely on the visualisation of the pore pressure distribution and/or the groundwater head results.

Figure 3. Pore water pressure and Groundwater head plots in PLAXIS Output