Hi there,
I would like to model an RC retaining wall in Plaxis 2D (V21). The wall has a varying thickness, which is 1.3 m thick at the bottom and 0.4 m thick at the top (please see the Figure below). And below the wall, there's a 1.4 m x 1.7 m footing (which then connects to a bored pile).
It is common practice to model such a wall with a plate element. However, I wonder how to correctly demonstrate the area (A) and inertial moment (I) value of this varying thickness.:
1. Can I model it as a single plate with an "average" thickness of (1.3 + 0.4)/2 = 0.85 m ? However, with this model, the EA and EI of the plate at the bottom (where it intersects with the footing) will be lower than reality, thus resulting in a lower moment force.
2. If I model it as a plate with an "average" thickness of 0.85 m, the moment force around the top of the pile might also get a bit bigger than reality (due to the higher EA and EI).
3. Should I average the plate into a few "sections" (e.g. the average is made every 2 m in length)?
I believe these are very simple questions for experienced Plaxis users. I am looking forward to hearing from you. Thank you for your time and attention.
Kind regards,
M. Rayyan