An advanced tip using the built-in command line in PLAXIS 3D

Figure 1. Pile-raft foundation with piles modelled as
embedded beams with different lengths

When having a complex model with a large number of embedded beams, for instance, in a pile group in a large pile raft foundation, or different types of rock bolts for a tunnelling project, the number of embedded beams can become overwhelming.

In that case, it would be great if you can easily find different groups of embedded beams to check e.g.:

• if all piles belonging to this group are all activated in a calculation phase
• select these piles to refine the mesh

Criteria to help us find these groups can be the length or the material that is assigned.

Filter by pile length

The length of an embedded beam is stored in the parent object of this object: the line object. So, we cannot display the length of an embedded beam directly, but we have to use the lines which have an embedded beam.

To generate a list with the length of the embedded beams, we can run the following tabulate command in PLAXIS 3D:

tabulate Lines "EmbeddedBeam Length" "EmbeddedBeam<>"

This works both for PLAXIS 3D Input's Structures mode and the Staged construction mode. However, this does not contain any phase activation information.

By adding the criteria for the active state to run this command in PLAXIS 3D's Staged construction mode, the command is now:

tabulate Lines "EmbeddedBeam Length EmbeddedBeam.Active" "EmbeddedBeam<>"

This will list the information for all phases; see the command executed in PLAXIS 3D 2017 below. Note that here we use the geometry from Tutorial Lesson 1(c).

0091> tabulate Lines "EmbeddedBeam Length EmbeddedBeam.Active" "EmbeddedBeam<>"
    Object EmbeddedBeam Length EmbeddedBeam.Active
    Line_6_1
       InitialPhase: EmbeddedBeam_1_1 20 False
       Phase_1: EmbeddedBeam_1_1 20 True
       Phase_2: EmbeddedBeam_1_1 20 True
       Phase_3: EmbeddedBeam_1_1 20 True
    Line_7_1
       InitialPhase: EmbeddedBeam_2_1 20 False
       Phase_1: EmbeddedBeam_2_1 20 True
       Phase_2: EmbeddedBeam_2_1 20 True
       Phase_3: EmbeddedBeam_2_1 20 True
    Line_8_1
       InitialPhase: EmbeddedBeam_3_1 20 False
       Phase_1: EmbeddedBeam_3_1 20 True
       Phase_2: EmbeddedBeam_3_1 20 True
       Phase_3: EmbeddedBeam_3_1 20 True
    Line_9_1
       InitialPhase: EmbeddedBeam_4_1 20 False
       Phase_1: EmbeddedBeam_4_1 20 True
       Phase_2: EmbeddedBeam_4_1 20 True
       Phase_3: EmbeddedBeam_4_1 20 True
    

If you are interested to see if all piles with a certain length are activated, you can also choose to make a group in Structures mode. Then you can check if all items are activated in a certain phase.

For example, you want to check for all embedded beams that have a length of 20 m, if they are activated in a phase.

1. We first create a group of all lines that have embedded beams using the groupfiltered command.
2. After renaming this new group (Groups[-1]) to something meaningful, we then further refine the filtering by lines with a length of 20 m.

The commands for this case will look like this:

groupfiltered Lines "EmbeddedBeam<>"   # to get all lines embedded beams 
rename Groups[-1] "EmbeddedBeamLines"   # change the group name to something meaningful 
groupfiltered EmbeddedBeamLines "Length=20"   # to filter out all embedded beam lines with length = 20 
rename Groups[-1] "EmbBeam_L_20"   # change the group name so we know the length 

Now you can check the group EmbBeam_L_20 to see if all group members are activated in the desired phase. We can see this directly from the Model Explorer, see below in Figure 2.

Figure 2. Overview of activation state of embedded beams in
Phase_3 grouped by length = 20 m

Filter by material

Another criterion you can use is piles to which you assign a specific material. The same approach can be used here to filter these. Instead of checking for the length value, we will use the material assignment for the embedded beams, using this criterion:
"EmbeddedBeam.Material=name_of_material"
in which <name_of_material> is the name of the embedded beam material dataset.

The tabulate command will now be:

tabulate Lines "EmbeddedBeam Length EmbeddedBeam.Material" "EmbeddedBeam.Material=name_of_material"

We can also directly use the properties of the embedded beams (the material assignment):

tabulate EmbeddedBeams "Name Material" "Material=name_of_material"

The group-and-filter command to make a group called EmbBeams_Mat1:

groupfiltered EmbeddedBeams "Material=name_of_material"
rename Groups[-1] "EmbBeams_Mat1"

Then, we can use the same approach to check if all items of this group are activated in a phase.

Note that if you e.g. want to refine the mesh locally for these embedded beams, you would need to create a group of their parent-lines.

Conclusion

Using the built-in command line options, we can create groups based on filtering criteria that enable us to see more details of our PLAXIS model.

Hint: If you want to get more detailed info, our Python wrapper can lead you to more detailed and filtered results.