unexpected results pore water preassure

[jpereirasan]

Dear stko team.
I am modeling a centrifugal test, the analysis is divided into gravity step and dynamic step.
the static results are well with what is expected and with what has been done by other authors, however in the dynamic analysis there are unrealistic results.

the pore pressures should increase as the analysis starts, however, they start to decrease and reach negative values.

i would appreciate if you could review my models check if a mistake is causing the bad results and please answer some questions.

1) to numerically simulate that the edge of a model is impermeable (not allowing water flow out of the model edges), should P be geometrically constrained at the edge?

2) do the p values obtained with uniform excitation correspond to the values of the excess pore pressure of a point or are they relative values?

3) for this case it would be valid to implement a free field columns or absorbing boundarys approach, I understand that not because of what you explain in this post (viewtopic.php?p=6511&hilit=centrifuge#p6511) (it is a model similar to mine).


kind regards

[jpereirasan]

Hi. STKO Team. I solved my doubts but the results are still not as i expect
Any recomendation or suggestion about why the pore pressure follows that behavior?
Here is the uploaded model.

[STKO Team]

Try to have a look at the centrifuge example they have in OpenSees:
https://opensees.berkeley.edu/wiki/inde ... Conditions