Question regarding 'update parameter' for hPerm/vPerm in pdmy02 with SSPquadUP elements

[javnetz2021]

Hello everyone,

I am currently working on a numerical model to simulate soil liquefaction using the PressureDependMultiYield02 (pdmy02) material model alongside SSPquadUP elements.

I have a question regarding the update parameter command when changing permeability (hPerm and vPerm). I attempted to apply a permeability update to a specific region of my model. However, I am observing pore pressure (PP) accumulation across the entire domain, including areas where the permeability is supposedly set to a high value (k = 10).

This leads me to suspect that the parameter update is being applied globally to the entire material tag, rather than being restricted to the specific region I intended to target.

Could someone confirm if this is the standard behavior in OpenSees/STKO? If the command inherently updates the parameter for the entire material globally, I assume the correct workaround is to define two completely separate material tags for the different permeability zones.

Any insights or confirmation on this would be greatly appreciated. Thanks in advance!

[STKO Team]

Unfortunately, the SSPBrickUP (as opposed to the others) only supports: xPerm, yPerm and zPerm parameters, as you can see from the source code:

PERM.png (66.31 KiB) Viewed 278 times