Applied Pore Pressure in quadup elements

[avytin]

how do i apply fixed pore pressure conditions in the nodes of a quadup element? Is it valid to use
an imposedmotion at dof 3 by using a groundmotion command with a constant velocity??

e.g. for node 1862
pattern MultipleSupport 3 {groundMotion 1 Plain -vel $Timeseries1862
imposedMotion 1862 3 1
}

[avytin]

I also checked with the creators of the up elements, and this is supposed to work fine if combined with Transformation constraint setting. My results verify this method of applying pore pressure.