A retaining structure constitutes a structural engineering construction, the purpose of which is to contain the earth pressure that may affect a specific work.

It may be a single work with a single project (as is the case of the construction of a retaining wall in order to obtain plots of horizontal surface), or it may be part of a larger project (such as, for example, a wall to contain the push of earth near a road, or "Screen (retaining structure)" screens for the construction of the basements of a building).

Rigid containment structures

"Rigid retaining structures" are those retaining structures whose movements are made of a rigid solid, but do not present movements inside the structure, that is, no bending occurs in it. Therefore, the law of thrust is influenced exclusively by the value, but not by the shape. They are the retaining walls.

Flexible containment structures

Flexible containment structures are those in which the movements of the rigid solid and the movements due to the bending of the structure itself occur in similar percentages. This deformation causes the movement of the structure to influence both the value and the form of the pressure law on the structure.

There are two types of flexible containment structures:

• - The "Screen (containment structure)" screens.

• - Shoring.

The main difference between screens and shoring is that shoring is much more flexible than screens.

Difference between walls and screens

The constitutive difference between walls and screens is that the walls are made either after the excavation has been carried out, or before filling is done. However, screens are always built before excavation, or at most, during excavation.