Boundary condition and interfaces in Pile supporting embankment



Hi @itascan,
In the above two examples, the piles have been assigned interface properties in different ways but one is in FLAC 2D and the other is in FLAC 3D.
In 2D, moi (moment of inertia) is also provided but in 3D, moi-y and moi-z have been assigned zero.
I need to model my piles in 3D but my case matches with the 2D example. hence, I am not able to clearly understand how the interfaces properties and the commands are assigned in these two cases.

It would be great to get some insights into the various interface properties and moment of inertia values for 3D case.

Thank you.

@Newuser,
The 3D example you show on the top simply changes the link properties on the bottom (and top) nodes of the pile. It’s really more intended to act as an anchor point in contrast to the rest of the pile links.

The 2D example is a better application for end-bearing capacity where the bottom link is actually deleted and replaced with a link that has a normal-yield conditions in the x-direction (along the pile). The new link just has normal stiffness and normal yield compression to simulate the end bearing capacity.

@dblanksma do you mean '3D" example is a better application?

Sorry, yes. However, the example the deletes and re-creates the link like this:


has both a 2D and 3D version. Regardless, it’s a better approach to model end-bearing capacity.