I have assigned a steel bridge with pad foundations with a vertical soil stiffness assigned (Kz). When I run the model however, the results map of the pad foundations show a -ve soil reaction, implying the soil is acting in tension.
Is there a way to make sure any reactions are zero if in uplift? I have tried ticking allowing selecting Uz+ when defining the Foundation elasticity, however seemingly to no avail!
Hope you can help!
Thank you for the speedy reply.
There are indeed instability warnings. I get an instability in one of the mesh nodes in the pad foundation, however it is a type 3. I was under the impression that this sort of instability usually occurs around rigid links due to stiffness differences?
I have applied line supports to ensure lateral stability (which you have applied i your model)
The analysis does not fully converge no, this seems to be associated with selecting the uplift as Uz+.
The analysis does not fully converge
In such case the results cannot be correct.
You may try to change the method to Full Newton Raphson and check if this help. Otherwise you have to examine the model and find out why this happens.