No convergence of nonlinear problem ??

[rodainnajjar1229]

Hello
i have model with static load + water uplift
i consider most of load as auxiliary load ,
and calculation two main combination load see pic 1
with nonlinear analysis options see pic2
but (No convergence of nonlinear problem)
i don t know the reason
kindly find attached file

[Artur.Kosakowski]

Out of curiosity (before investigating the model) - do you expect (allow) for any uplift within the raft foundation of a building? My assumption would be thet it should be pressure on the soil below for the entire area of the foundation.

[rodainnajjar1229]

I used non linear analysis to cancel tension force on soil springs , and i tried this option in other project without any problem ,

but in this case i will increase thickness of raft until raft weight  is larger than water uplift  but i still  have  the same problem

Regards

[t.sautierr]

You can perfectly anchor your raft in the soil and then have some situations there is no pressure on soil. Eg: having enough OW for a normal level of undergroundwater, but need to anchor when water raises an exceptionnal level.

I'am currently doing it near Paris. Raft 60cm and micropiles to make the rest. Otherwise I should have had a 1.00m raft.

What I personly wouldn't do is to have something not equilibrate by OW with normal conditions (ie: always with anchors in tension).

What's your experience guys on that in other countries?

[Artur.Kosakowski · Accepted solution]

The solution is to increase the tolerance a bit (e.g. 5e-3). Mind to run model generation before launching calculations.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[Artur.Kosakowski]

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t.sautier wrote:

You can perfectly anchor your raft in the soil and then have some situations there is no pressure on soil. Eg: having enough OW for a normal level of undergroundwater, but need to anchor when water raises an exceptionnal level.

I'am currently doing it near Paris. Raft 60cm and micropiles to make the rest. Otherwise I should have had a 1.00m raft.

What I personly wouldn't do is to have something not equilibrate by OW with normal conditions (ie: always with anchors in tension).

What's your experience guys on that in other countries?

---

Thank you Thomas.

[rodainnajjar1229]

i design many project in gulf
when we have water uplift larger than OW there are 2 solutions
1-Increase OW .
2- use Tension Piles.
in my case OW is larger than uplift ,but i have part in ground floor haven t enough OW
Regards

[rodainnajjar1229]

thank you Artur

[t.sautierr]

Then it is ok -> there is a possible equilibrium.

[Anonymous]

i am getting the same error in a simple model, can you help me? file is attached

[rodainnajjar1229]

hi maurojgramos
you have high water uplift value , so should to add tension piles or increase self weight
Regards