Overturning of Footing - Base Pressures

RE: Overturning of Footing - Base Pressures

Micha van der Sloot — Tue, 31 May 2022 16:46:50 GMT

Great to hear you found out what the cause was!

Kind regards,

Micha

RE: Overturning of Footing - Base Pressures

Timothy Steward — Tue, 31 May 2022 07:25:36 GMT

I have solved the issue

It was because i modelled the foundation material as Undrained(B). This caused the pore pressures to increase due to loading even though it was above the water table. The excess pore pressures generated meant total stresses were not equal to effective stress and the appearance of tension at the foundation interface was in fact related to pore pressure.

RE: Overturning of Footing - Base Pressures

Micha van der Sloot — Mon, 30 May 2022 22:02:21 GMT

Hi Timothy

Two things might explain this:

is the soil model you are using in the interface having a tensile strength defined? For instance if tension cut-off is activated at a tensile strength of zero, then in the plastic points plot, you should also see tension cut off points in this area.
from the plots, it seems you have your interfaces tightly wrapped around the concrete footing. Care should be taken here by slightly extending the interfaces (with Rinter = 1.0/rigid for the extension), as mentioned in the PLAXIS 3D Reference manual in the part about "Interfaces around corner points".

If that does not solve your issue, can you please submit a service request here: apps.bentley.com/.../ProductSupport