Problem description

In PLAXIS 3D 2025.1.0 and 2025.1.1, when point loads are applied at the top of embedded beams and an interface element exists at the same coordinates, the point loads are incorrectly merged into single point load(s).
This behaviour does not appear in the Input program, but becomes visible in PLAXIS 3D Output, where a combined load is shown instead of the individual loads.

For a better understanding, consider the following example:

• Point loads defined at the top of embedded beams appear correctly in PLAXIS 3D Input.

• Internally, these loads are merged to a smaller number, resulting in incorrect point loads application, and consequently in wrong results. This is visible in Output when inspecting the calculation results (e.g., deformed mesh, etc.).

 

This issue only occurs when an interface element shares the same coordinates as the embedded beam’s top point, where the point load is applied, e.g., case of modelling pile-raft foundations.  

The merging of point loads will lead to different load distribution compared to the assigned  one, and since the analysis is based on the incorrectly combined  load, this will affect analysis outcomes and accuracy. 

Workaround

This issue is now resolved with the release of PLAXIS 3D 2025.1.2. Download the latest PLAXIS version here.

A workaround to prevent point loads from merging when applied at the top of embedded beams with overlapping interface elements requires the following:

• Add a standard beam element (not an embedded beam) to the top of the embedded beam.
• This beam should extend beyond the interface coordinates where the original point load needs to be applied.
• Configure the beam to be very stiff (to ensure proper load transfer without deformation) and consider a zero weight (to avoid adding extra self-weight to the model).
• Apply the new point load to this additional beam element. 

The load will then transfer correctly to the top of the embedded beam without merging issues.

Another option for projects that were originally created and saved using a version prior to version 2025.1.0 or 2025.1.1, is to continue working on the project using the previous version of PLAXIS 3D, e.g. PLAXIS 3D 2024.3. This is possible because even when opening a project in the latest version, the software converts the project without replacing the original file.

Note that when installing PLAXIS 2025.1 it is possible to have multiple versions installed on the same machine (e.g., 2025.1 alongside a previous version). By using the previous version, you can avoid this particular issue of the merging of point loads while maintaining compatibility with your existing project.

This issue is now resolved with the release of PLAXIS 3D 2025.1.2. Download the latest PLAXIS version here.