A retaining wall refers to a structure designed and constructed to withstand the lateral pressure of soil. A retaining wall is also constructed to hold back soil materials so that the wall doesn’t fall flat on the ground. Many reasons add to the lateral pressure of the soil – liquid pressure, earth filling, sand, and the presence of other granular materials. When a retaining wall is built, all these materials remain behind it. It saves the wall from sliding, thereby keeping erosion and accidents at bay.
A retaining wall resists the pressure that arises when ground elevation exceeds the repose angle of the soil. It is also used to support the soil laterally so that it can be retained at varied levels on both sides. The role of a retaining wall is to bound the soil between two different elevations in the areas where the slope is undesirable.
Gravity wall uses its composition (stone, concrete or other material) to withstand the pressure behind the wall. These walls are made using mortarless stone. Sometimes, segment concrete too is used to design limestone retaining walls. A gravity wall is massive and is considered to be an affordable option for a height up to 3 meters.
A crib retaining wall is a form of gravity wall. It is constructed by interlocking separate blocks or boxes. These boxes are made using precast concrete or timber. They are further filled with coarse granular or crushed stones to offer a free-draining structure. A crib retaining wall is best-suited for planter areas.
This retaining wall comprises a wall connected to the foundation. If well-engineered, it is capable of holding back a significant amount of soil. It rests on a slab foundation where the latter, too, is loaded by backfill. Eventually, the weight of the backfill makes it easier for the wall to hold soil and also protects it from sliding and overturning.
A counterfort retaining wall is a cantilever wall strengthened using counter forts monolithic with the back of the wall slab and a base slab. The counter forts, so added, act as tension stiffeners. They also connect the wall slab and base that helps to reduce bending. Counter forts are used for walls with greater heights.
Also known as MSE retaining wall, it is referred to as the most common and economical option in constructing retaining walls. This type of wall is supported by the fills or granular and is further held together by reinforcements. Such reinforcement could either be plastic meshes, metallic strips, or any other material.
This kind of wall is constructed by reinforcing the soil by adding passive bars. The bars are stood parallel to each other and are slightly inclined downward. The bars also act in providing a bend or shear to the wall.
An anchored wall is built in different styles mentioned above. It is ideal for all the areas where the space is limited. This type of wall is suitable for loose soil over rocks. This wall structure system is also used to construct other high retaining walls.
As the name suggests, it makes the use of deep cable rods and wires that are driven deep sideways on the ground. The ends are then filled with concrete to provide an anchor. Such a design saves the wall from sliding pressure or overturning.
Another option of retaining walls built in the regions with space constraints is the sheet piling retaining wall. It is a thin wall made using wood, steel, or vinyl driven directly into the soil. It includes a vertically corrugated structure that provides extra reinforcement to the arrangement.
It is essential to mention that these pilings only fare well in softer soil. Thus, if the soil is hard, you cannot stand a sheet piling retaining wall on the structure. If you are building a larger sheet piling retaining wall, make arrangements for additional anchoring as well.
A composite retaining wall or hybrid wall system makes use of both mass and reinforcement to attain stability.
When it comes to constructing retaining walls, options are many. Common options such as prefab concrete blocks, wood, and natural stone are seen everywhere. Other options include bricks, stone veneers, and poured concrete. The cheapest of them all is wood. Poured concrete is touted as the strongest and most durable choice.
In wooden retaining walls, poured concrete acts as a base to provide extra strength to the arrangement. In many cases, natural stone is also used in making retaining walls. The rock is cut into the blocks or used in its original shape during the process of construction. The walls made using natural stone do not use a base.
Choosing the right material for the construction of a retaining wall is entirely subjective. Apart from personal preference, logistics should also be taken into consideration while selecting the material. The other deciding factors are the practicality of the material, your budget, etc.