Earth Pressures ~ these can take one of two forms namely:-
Active Earth Pressures † these are those pressures which
tend to move the wall at all times and consist of the wedge
of earth retained plus any hydrostatic pressure. The latter
can be reduced by including a subsoil drainage system behind
and/or through the wall.
Passive Earth Pressures ~ these are a reaction of an equal
and opposite force to any imposed pressure thus giving
stability by resisting movement.
Medium Height Retaining Walls