This article provides practical examples of the reference-target phase comparison workflow for identifying staged construction changes in PLAXIS Input, as explained in the article "Quickly Identifying Staged Construction Configuration Changes in PLAXIS".

Using representative modelling scenarios, it demonstrates how differences in the activation state of soil clusters, structural elements, loads, and groundwater conditions are displayed, helping users quickly review and verify changes between construction phases.

Quickly navigate to:

• PLAXIS 2D Example
• PLAXIS 3D Example

 

PLAXIS 2D Example – Phase Comparison

 

Assume the reference phase is Phase_1.

If geometry is hidden in Phase_1 and the model is switched to Phase_3 and _4, only the changes relative to Phase_1 are displayed. 
Switching back to Phase_1 shows the original state of these objects, as shown in the figures below.

Figure 1: Reference phase, Phase_1 with active objects and features

Figure 2: Reference phase with hiding all the geometry from the model explorer

 

Model conditions in Phases_3, and _4 compared to the baseline configuration established in reference Phase_1

In Figures 3 and 4, only objects whose activation status differs from that in reference Phase_1 are displayed. Objects that remain in the same activation state, whether active in both phases or inactive in both phases, are not shown. 

In Figure 3, the embedded beams are visible because they are activated in Phase_3 relative to the reference phase. 

In Figure 4, the embedded beams, anchors, and cables are visible because their activation status differs from that in reference Phase_1.

Figure 3: Model condition in Phase_3 compared to the baseline configuration established in reference Phase_1

Figure 4: Model condition in Phase_4 compared to the baseline configuration established in reference Phase_1

 

PLAXIS 3D Example – Phase Comparison

 

Assume the reference phase is Phase_1. The visible objects represent the staged advancement of the tunnel, including activation of the TBM plate, associated interfaces, and tunnel lining segments installed after the tunnel reaches their designated position. At each advancement stage, an additional 1.5 m length of tunnel lining is activated relative to the reference phase.

If geometry is hidden in Phase_1 and the model is switched to Phase_3 and _4, only the changes relative to Phase_1 are displayed. Switching back to Phase_1 shows the original state of these objects, as shown in the figures below.

 

Figure 1: Reference phase, Phase_1 with active objects and features

Figure 2: Reference phase with hiding all the geometry from the model explorer

 

Model conditions in Phase_3 and _4 compared to the baseline configuration established in reference Phase_1

In Figures 3 and 4, only objects whose activation status differs from that in reference Phase_1 are displayed. Objects that remain active or inactive in both phases are not shown.

In Figure 3, the tunnel front has moved one slice forward, with applied loads to the front and sides being visible, and the activation of the plate element with contraction applied.

In Figure 4, the tunnel front has moved one more slice forward, with the applied loads now moved to the current front and sides being visible, and the activation of the new plate element with contraction applied.

Figure 3: Model condition in Phase_3 compared to the baseline configuration established in reference Phase_1

Figure 4: Model condition in Phase_4 compared to the baseline configuration established in reference Phase_1