I have a Validation > Model > Slab/Mats > “Foundation mat with ground bearing springs not meshed” warning. Why do I get this and how do I resolve it?

Environment

Not environment-specific

Question

I have a Validation > Model > Slab/Mats > “Foundation mat with ground bearing springs not meshed” warning. Why do I get this and how do I resolve it?

Answer

When you define a mat foundation using the Foundations ribbon tab > Mats group you can define the Soil Parameters including the Use ground bearing springs option within the Properties window.

With this option checked the mat is supported on ground bearing springs located at the analysis mesh nodes to model the soil interaction under the foundation. This is achieved in the underlying solver model by including the mat’s stiffness (both in-plane and out-of-plane) in the analysis model.

When you place a mat foundation in the model the level in which the mat foundation is created is automatically included in the analysis by checking the option “Mesh 2-way slabs in the 3D analysis”. For further details on this option please refer to the related article “When should I use the "Mesh 2-way Slabs in 3D analysis" option?”

You will therefore obtain the validation warning “Foundation mat with ground bearing springs not meshed“, if you have removed the check from the option “Mesh 2-way Slabs in 3D Analysis” on a level that has a mat foundation defined that uses ground bearing springs.

You can double click the Foundation mat with ground bearing springs not meshed or individual item to select and locate it in the active scene view. If the item is not in the active scene view then the Structure 3D view is opened and set active. Alternatively, you can right click and choose Highlight Items from the context menu. If you select the highlighted item in the active scene view the Properties window will provide details for review and editing. The Plane option tells you which level it exists on.

The resolution is therefore to ensure a check against the option “Mesh 2-way Slabs in 3D Analysis”.

Once the level has been included in the 3D analysis, the validation warning is no longer issued.

The remaining warning is covered in a separate article “I have a Validation > Model > General > “Supports exist within area of Mat Foundation” warning. Why do I get this and how do I resolve it?”