Compression only springs - Volumetric structure

[ignaciomcabrera]

Hi! 

I'm trying to analyze an isolated foundation pier of a route signal but I'm not sure if I'm doing it correctly (image below). 

I modeled a volumetric object and gave elastic supports with the soil stiffness value to the nodes of the FE mesh. The model runs properly but, the problem is that springs are taking tension forces and I don't know how to desallow this behaviour.

The main idea is to compare a Sulzberger analysis made by spreadsheets with the model, the concept is that the soil gives support to the foundation. You will note that one side of the volumne doesn't have springs, this is because the excavation will be on that side and the stiffnes of the soil is not longer considerable.

Despite the fact that we have the "Elastic foundation parameters" option, this is only for slabs. Also the "member elastic ground" is only for members.

Any suggestion??

.rtd attached

Thanks!!

[Rafacascudo · Accepted solution]

Not sure why you had to do it on Volumetric type analysis , but you can always use the "uplift" option for nodal supports . It also works with elastic supports

[ignaciomcabrera]

Obrigado Rafa!

As I said, I'm not sure if the volumetric analysis is correct, which one would you use for this case?

I´ve done what you suggested and apparently works ok! What do you think? (see new attached)

Thanks again!

[Rafacascudo]

sorry for the delay. If the section is a solid square and you have different conditions of support on each of the four faces , then I think you chose the correct structure type.