Stiffness variation of bedding material

I am about to start modelling a tunnel with a length of +700 m represented by 2D shell elements (3D model modelled in Teddy). The base slab of the tunnel is to be supported by vertical and tangential soil springs, most likely represented by a bedding material (BMAT in AQUA). The vertical soil springs should represent the behaviour of the existing soil.
A sinusoidal stiffness variation of the soil in the longitudinal direction of the tunnel shall be introduced in the FE-model. This can be introduced by dividing the base slab into discrete small areas and then assign different bedding materials for each area. This is however not very convenient, as it requires that the FE-model is divided into multiple small parts. Is there a smarter way in SOFiSTiK to define varying support conditions for shell models? It would be nice to freely be able to apply changes of the support stiffness (BMAT) of the base slab without having to subdivide the base slab into smaller areas and apply different bedding materials for each area.


Unfortunately, I don’t know of a simple workflow for varying the bedding material.
Have you tried using loops for the sytem creation? Within these loops you can define different sections with different bedding materials.
Apart from the basic (CADINP) programming functions (loops, variables,…) I can’t think of anything else.

Best regards
Frederik Höller
Your SOFiSTiK Support Team