Following the last experiments with interfaces and beams, I'm now adding tiebacks to the model, but I can't get pretensioning to work. The rest of the analysis seems generally ok, but the pretensioning doesn't work and the anchor just sits there as a simple spring.

I'm attaching the associated script.

I made some modifications in your script (for tieback). the tieback gets load right now but since I don't have any reference to check against with I really can not say if it's working correctly.

I need to spend a little more time and run some baseline models to make sure tieback is behaving correctly.  thanks for bringing it up.

while I'm debugging tieback element, is it possible for you to document what you did to generate this script? your experience might help others in this topic. I really don't have time to create example manual and your experience is going to be perfect example. couple of pages with figures would be sufficient.

thank you  in advance.

by the way I did find a bug in tieback pretension implementation which is fixed now. I will release the revised code soon.

Thanks again. The pretensioning of tiebacks is now working. However, the bending moments on the walls when pretension is applied seem too large as if the pretension load is applied by meter of wall and not by anchor. I've ran it again with the pretension load divided by the anchor spacing and the results seem ok now. I'm attaching the revised script alongside the bond stiffness correction you pointed out.

Regarding the documentation of the examples, I could help create an examples manual during the next months. I'll start a thread to allow users to suggest examples to solve.

tieback pretension initialization has been revised in the new version (i.e. V2.3).