Plate spring supports

This tool calculates the spring stiffness of each node in a slab or footing that is supported on an elastic material such as soil. Because the meshing of the slab or footing generally results in elements of various shapes and sizes (as you can see in the image below), calculating the tributary area of each node in order to determine its spring stiffness is not straightforward, and so this tool is provided to automate the process.



Operating the tool involves selecting all the plate elements in the slab or footing, right-clicking and then selecting "Plate Tools" => "Generate Plate Spring Supports" from the popup menu that appears. You should then specify the subgrade modulus of the soil and click Ok.



The tool generates a spring support under each node (based on its tributary area multiplied by the specified subgrade modulus) and inserts a compression-only member between the spring support and the slab or footing.


If you have ticked "Overwrite restraints already applied to nodes" then any restraints that already support the slab or footing will be replaced.