Question

What causes Lateral Earth pressure?If you look at the side of an embankment the soil seems to stay there forever and doesn't move.  If you build a wall there then there is pressure exerted on the wall.

Answer 1

Imagine if you excavate the soil and do not build the wall then what will happen?

The soil will collapse. Thats why that initially it may look like the soil is not moving but eventually after the construction of wall, the soil moves with the passage of time and exerts all its pressure to the wall and that's why we always design an appropriate wall to support any embankment may also be called retaining wall.