Hi,

I'm in the process of developing a script for deep excavations with diaphragm walls and several ground anchor levels. For now, I've managed to get a small script running for just a single level tieback but with no interfaces. I've attached this script to the post.

The problem is when I try to include the beam/soil interfaces as I can't seem to assign both at the same location. It really must be my poor judgment but I really can't get it to work. Does anybody know the procedure to do this?

Thanks!

what do you mean by "both at the same location"? please clarify.

sorry for not being clearer
I'm trying to model the interface of the retaining wall with the surrounding ground, so I first tried to define the interface and then attach the beam to this element. However, nothing happens.

you can not do that. please use liner element instead which will automatically attach one interface between solid element and beam for you. no manual interface attachment required.

please make sure that liner element will only attach to the boundary edges (edges sharing one element only). so you can excavate the region that bean will not be attached to it and use liner element and back fill if you want. hope this help.

I'll try that. Thanks!

I've been struggling to get the liner elements to work. I attach two scripts that generate an excavation with a simple cantilevered diaphragm wall using beam and liner elements but the later doesn't seem to converge. I've tried to change the "ADONIS_Sheet_Pile_V2.0" script that is available on the forum but it suffers from the same problems.

Could someone post an example on how to properly use liner elements with ADONIS?

currently liner element can only handle one side interface element. so somehow the embed part of sheet pile need to be fixed to the soil otherwise model does not converge. one solution would be to use to pieces beam-liner elements. use beam element for the embedded part and liner for the part that exposed. the connection will be connected using equaldof from "Structural Nodes B.C. List". this way the embedded beam element will support the liner elements and prevent it from one sided movement.

please give it a try if you could not make it I'll take a shot at it this weekend.

I eventually gave up on liner elements and decided to model the interfaces directly with thin continuum elements. This of course eats up on computational time as the mesh must be smaller but I'm getting better results. I enclose the script for this model.

Thank you again for your help and your great software.

here is how I would do it with beam+liner+interface combinations.

I would appreciate if you be able to document these works. other users will find it very useful. simple verification manual with couple of pages would be sufficient.

thanks again for your work.

It works brilliantly and the results are more or less the same as for the interface modelled explicitly with continuum elements. For this problem it works great and the results are similar to what is obtained with a Winkler elasto-plastic spring approach.

Nevertheless, as there is no interface modelled for the lower part of the wall, for some problems it could lead to an overestimation of the passive pressures on the wall toe and an underestimation of active pressures. Additionally, for multi-level anchored or propped walls it could probably not be an applicable process.

I have been working on liner element with both sided interface for a while but it's not ready yet. meanwhile you can use whatever trick you have got in your sleeve to get around it until liner element formulation is ready.

Can someone please explain what is meant by "liner element" in this conversation? There is no liner element available under the structural elements module. Is this liner element located somewhere else?

Context: I'm trying to figure out how to model an anchored flexible wall.

Ricyteach,

you are right there is no liner element in ADONIS. I mixed up syntax from some other programs in here. what I meant by liner element was beam element with interface. in the FLAC program it's called liner element in here it has no meaning. sorry for confusion.

-Roozbeh

in the new version interface for both sides of beam element is available.