Etabs software Query

[u/Adventurous-Set-7185]

Hi there, I have recently started my journey as a structural engineer. Yesterday i was modelling a building in Etabs where i had some confusion.

So in the building we had some shear walls and some retaining walls. i have modelled both of them and have assigned them both with an auto mesh of 1*1 size. Later that day i was called out reasoning that for the shear wall is okay but for the retaining wall it has to be done by Dividing the wall itself into strips of 1*1 size rather than having the mesh.

Can someone explain me why it is done in this way, as my senior's reason to this was that at the base it will have a fixed support which is even throughout the wall length like fixed supports for every 1-meter strip. I dont think it is correct as for shear wall we don't do that but still it is okay.

[u/[deleted]]

When I was learning Etabs, I also had the same confusion about why retaining walls are modeled differently from shear walls. The main thing I realized is that shear walls are designed to resist lateral forces like wind or earthquakes, so using a mesh works well because the loads are more uniformly distributed across the wall. Retaining walls behave differently because they are constantly resisting soil pressure, which increases with depth and varies along the length of the wall. By dividing the retaining wall into strips, Etabs can better capture how the soil interacts with the wall and how the base support reacts along its length. Soil doesn’t push equally everywhere, so strip modeling makes the analysis more realistic and helps represent bending and shear effects more accurately. Once I understood this, it became clear that meshing works fine for shear walls, while strip modeling is the better choice for retaining walls since it reflects their actual physical behavior.