You can create a pore pressure boundary condition to specify the excess or
total pore pressure in a porous medium. If no gravity load exists in the model,
you must specify excess pore pressure. If the model contains any gravity load,
you must specify total pore pressure. (For more information, see
“Boundary
conditions,” in
Coupled Pore Fluid Diffusion and Stress Analysis.)
Display the pore pressure boundary condition editor using one of the
following methods:
To create a new pore pressure boundary condition, follow the
procedure outlined in
Creating boundary conditions
(Category: Other;
Types for Selected Step: Pore
pressure).
Select an analytical field to define a spatially varying boundary
condition. Only analytical fields that are valid for this boundary condition
type are displayed in the selection list. Alternatively, you can click
to create a new analytical field. (See
The Analytical Field toolset
for more information.)
The Distribution option appears in the editor
only if you are creating the boundary condition or editing the boundary
condition in the step in which it was created. This option is unavailable if
you select the Fixed at current magnitude method.
If you selected the Uniform or analytical field
distribution option, perform the following steps:
If applicable, enter the magnitude of the excess or total pore
pressure in the Magnitude field.
If applicable, click the arrow to the right of the
Amplitude field, and select the amplitude of your choice
from the list that appears. Alternatively, you can click
to create a new amplitude. (See
The Amplitude toolset
for more information.)
Note:
The Magnitude and
Amplitude fields are unavailable if you are creating the
boundary condition in the initial step (in which case the magnitude is always
zero) or are fixing the magnitude at its final value from the previous general
step.
Click OK to save your data and to exit the
editor.
If you selected the User-defined distribution
option, perform the following steps:
If desired, enter the pore pressure magnitude in the
Magnitude field. Magnitude data that you enter in the
editor are passed into the user subroutine.
(The Magnitude field is unavailable if you
are creating the boundary condition in the initial step.)
Click OK to save any entered data and to exit
the editor.
In the job editor, click the General tab, and
specify the file containing the user subroutine that defines the boundary
condition. For more information, see
Specifying general job settings.
Note:
You can specify only one user subroutine file in
the job editor; if your analysis involves more than one user subroutine, you
must combine the user subroutines into one file and then specify that file.