What is a retaining wall?

A retaining wall is a structure that serves to prevent a mass of matter, usually earth or rocks on a slope, from falling or collapsing.

Some construction projects require removing soil or cutting away segments of a mountain, leaving voids or very vertical faces that may crumble and collapse. In these cases, it is necessary to include retaining walls in planning the project.

What types of retaining walls are there?

Different retaining walls will be built depending on the characteristics of the land, as well as the shape and needs of each site. These can be:

• Rigid: made of masonry or concrete; they create immovable structures.
• Flexible: made with structures and materials that are less rigid; able to yield a little to the load to which they are subjected without breaking.

There are different types of retaining walls, according to their method of construction and functioning; some of these are:

• Anchored: these have bolts anchored to the vertical ground that support soil loads and water erosion. 
• Gravity: their dimensions allow them to counteract the pressure exerted by the soil to be contained with their own weight.
• Reinforced gravity: built in an inverted T-shape or L-shape. These are built out of reinforced concrete. The base or foot of these walls is braced underground.
• Piled: driven into the ground at a great depth by specialized machinery.
• Reinforced floor: built with thin layers of natural material (earth and gravel) that are compacted and superimposed. This material is contained in some metal reinforcement. 
• Reinforced ground: similar to reinforced floor retaining walls, but these incorporate geotextiles as reinforcement. Geotextile is a synthetic, permeable fabric that acts to separate soils of different grades (making them more stable), as well as to protect and reinforce.
• Prefab: assembled with blocks or parts; used for quick solutions with few technical requirements.

What should be taken into account when building a retaining wall?

In planning and calculating the structures of the retaining walls, a huge number of factors must be considered. To this end, the Finite Element Method (FEM) is used.

FEM is used to solve problems in mathematical models and physical engineering models that work with differential equations. Some of the method’s fields of application include analyzing structures, heat transfer, and electromagnetic potential, to name a few. There is different software available today to apply this method.

In the case of retaining walls, the Finite Element Method enables calculating load stresses, ground movements, and any deformation in the structure, thus ensuring that the walls are able to withstand the loads efficiently, durably, and safely.