Underground shaft with opening

I am trying to create a shaft with an opening, under the earth pressure (simplified here by a well-distributed load of 100 kPa). However, the result was about E+12 cm for displacement! (A quick test by Robot structure gives me only some centimeters).
Does anyone have an idea about what can be the source of this error?
Thank you in advance for your help!

pointsList RG - sans liste pointes.gh (39.2 KB)

Hi make sure to flatten your inputs so that you only have one model.

Are your units and model size correct? You have a 1cm thick concrete shell which is 20x30m tall. Therefore it is expected that you would have high displacements

Yes, the thickness has to be 1m. Thank you for your remark, a displacement of 0,2 cm is reasonable now.