Overlapping Members double addition of weight

I plotted a top line model of box girder segment of a segmental bridge using quad elements in sofiplus. The haunch at deck gets overlapped with the web of the section. Due to this, weight of members at the junction is added twice. I tried to union the two areas but it is not possible since they themselves do not overlap and also lie in different plane.

So is there any solution to avoid this error ?


This is a common question for a structure discretized with surface elements.
Overlapping elements and therefore increased stiffness and dead load is a result of the chosen modelling simplifications.
If you don’t accept these simplifications you have a few modelling options.

  1. Use elements without dead load in the overlapping areas
  2. Use coplings, now you can shorten the web
    → This allows you to create stiff conections and no overlapping zones

In the end it is up to you to decide if the simplifications are reasonable and if they can be accepted or not. If you are unsure, it is best to ask a colleague for a modeling suggestion.

Best regards
Frederik Höller
Your SOFiSTiK Support Team