Is there anyway in PLAXIS 3D to apply an initial Pore Pressure at specific depth?

Question

I am running a research to compare the pore pressure dissipation and consolidation time. for this purpose I need to have an initial High-pore pressure (excess pore pressure) at different depths that was cuased by ground compaction. So i am wondering if someone has an idea how can i apply it. 
 NOTE that I tried to change the water conditions in the boreholes from head to hydrostatic and user defined, But this did not work for my case. Because during dissipation the software considers this level as the natural one and stop calculations as soon as the pore pressure reach it. 
 
 for example, at the surface the normal pore pressure is 0Pa, but I want it to start at 2 Pa. and then I would like the software to measure the required time to dissipate it till I get the 0Pa. 
 
 Thanks

Dennis Waterman · Answer

Dear Walid, 
 It's not possible to directly apply an excess pore pressures in a soil area because excess pore pressures are calculated results, not input pore pressures. 
 However, there is a trick you can use to still apply for instance 2 kPa excess pore pressure in a certain layer, but it would require 2 extra calculation phases 
 
 in Phase X 
 
 Apply a user-defined pore pressure of 2 kPa in the layer where you would like to have the 2 kPa excess pore pressure 
 In the Phase Settings under "Deformation control parameters" set the option "Ignore undrained behaviour". This will assure that applying the user-defined pore pressure will NOT lead to generation of excess pore pressures.

Phase X+1
 
 Remove the user-defined pore pressure again, hence set the water conditions to global 
 Do NOT use the option "Ignore undrained behaviour" in this phase. Now removing the 2 kPa water pressure is done undrained and will lead to a 2 kPa excess pore pressure

Phase X+2
 
 Do your consolidation analysis

Some notes: 
 
 This only works if the soil is set to Undrained A or Undrained B 
 Since water is considered slightly compressible, a 2 kPa user-defined pore pressure will give an excess pore pressure slightly smaller than 2 kPa, for instance 1.9 - 1.95 kPa. So if you really need 2 kPa, you will have to apply a slightly larger user-defined pore pressure. 
 
 Hopefully this helps, 
 With kind regards, 
 Dennis Waterman

Dennis Waterman · Answer

Dear Walid, 
 Just select the area in Phase X+1 and in the Selection Explorer set the Waterconditions to Global. This is also how you apply the user-defined pore pressures in Phase X, not in the borehole. 
 With kind regards, 
 Dennis Waterman