Symptoms

Users may experience one or more of the following symptoms when reviewing results in Output:

• Not all UDSM state parameters are available for contour plotting.
• Only the state parameters of one soil model appear, even though multiple different UDSM are used in the calculation.
• The calculation itself completes successfully, but post‑processing options are limited.
• Switching between phases does not expose additional state parameters for other UDSM active in the same phase.

These symptoms can make it challenging to fully interpret results when advanced soil model analyses rely on multiple UDSM.

Problem description

In PLAXIS 2025.1.x, when multiple different User Defined Soil Models (UDSM) are assigned within the same calculation phase, not all state parameter results are available for contour plotting in Output. In such cases, Output only exposes the state parameter results of the first UDSM encountered, while state parameters belonging to other UDSM used in the same phase are not shown.
This limitation affects all User Defined Soil Models (UDSM), including models delivered with PLAXIS (such as NorSand, PM4Sand, PM4Silt, CASM, N2PC) as well as user‑imported UDSM DLLs.

When this issue occurs

This issue occurs when:

• More than one different UDSM is active simultaneously within a single phase.

When this issue does not occur

This issue does not occur when:

• Only one UDSM is active per phase, even if different phases use different UDSM.
• Working with PLAXIS 2024.3 or earlier
• Multiple UDSM are present in the project, but assignment and activation are separated per phase.
• All State parameter results are available via the table view and selected curve points.

Impact

• Users may be unable to visualize or compare all relevant UDSM state variables.
• Interpretation of results may be incomplete when combining different constitutive models in the same phase.
• This limitation affects visualization post‑processing only; calculation results themselves are not invalid.

All State parameter results are available via the table view and selected curve points
Due to the complexity of the behaviour and timing constraints, this issue could not be fully resolved in the current update packs.

Solution / Workaround

This issue is now resolved with the release of  PLAXIS 2D/3D 2026.1.

Two workarounds are currently available.

Option 1 – Continue using PLAXIS 2024.3 (Recommended)

For projects that:

• Require multiple different UDSM active in the same phase, and
• Depend on full access to all UDSM state parameters in Output

We recommend continuing to use PLAXIS 2024.3, where this limitation is not present.
This provides the most reliable workflow for advanced UDSM‑based modelling.

Option 2 – Use a workaround in PLAXIS 2025.1.x (Limited)

A workaround is available under specific conditions.

How the workaround works

If there is at least one phase in which only one UDSM is active, Output allows you to select state variables for that model. Once selected, the chosen state variable remains available when switching to other phases.

Steps

1. Open Output for a phase where only one UDSM is active.
2. Select the desired state variable for contour plotting.
3. Switch to another phase of interest.
   The selected state variable remains available.
4. Review the results.
5. To view a different state parameter, repeat the process starting from a phase where the corresponding UDSM is the only active model.

Important notes

• This process must be repeated for each state variable.
• The workaround may also be usable when UDSM activation is staggered or swapped between phases.
• This approach may not be suitable for all modelling strategies and should be used with care.
• All State parameter results are available via the table view and selected curve points.

This issue is now resolved with the release of  PLAXIS 2D/3D 2026.1.