Retaining walls are structures that help in maintaining the surface of the ground at different elevations on either side of the structure. If there is no retaining wall support, the soil at a higher elevation would tend to move down till it acquires its natural, stable configuration.
Consequently, the soil that is now retained at a steeper slope than it can sustain by virtue of its shear strength exerts a force on the retaining wall.
Different Types of Retaining Wall:
Following are the most used types of retaining wall,
- Gravity Retaining Wall
- Cantilever Retaining Wall
- Counterfort Retaining Wall
- Buttress Retaining Wall
- Crib Retaining Wall
- Gabion Retaining Wall
- Sheet Pile Retaining Wall
- Anchored Earth Retaining Wall
- Diaphragm Retaining Wall
- Reinforced Retaining Earth Wall
1) Gravity Retaining Wall:
It is most popular types of retaining wall. Gravity wall assures its stability by its own weight. These walls are majorly designed to eliminate the overturning effect of the lateral earth pressure and do not induce tensile stresses within the section. Gravity retaining walls are suitable for the low height and are not economical for large heights. It can be made from stone, bricks, mass concrete, and precast concrete blocks.
Its section is of trapezoidal shape with a base width between 0.3 and 0.5 H, where H is the height of the wall and top width is between 0.2m to 0.3m. In the case of a concrete gravity retaining wall, a top width of 0.3 m is recommended for proper placement of concrete.
2) Cantilever Retaining Wall:
Reinforced concrete cantilever types of retaining wall are recommended for heights up to 7 m. This type of wall has a vertical stem monolithic with the base. A slender section can be used in this retaining wall the tensile stresses within the stem and the base is resisted by steel reinforcement. In case the slope of the wall is exposed a small backward batter of about 1 in 50 is provided in order to compensate for any forward tilting of the wall as shown in Figure.
3) Counterfort Retaining Wall:
Counterfort retaining walls are used for height more than 6m. Its stem provided act as slab spanning between the counterfort supports. The distance between support is about 2/3 H but should not be less than 2.5 m.
4) Buttress Retaining Wall:
A buttress wall is a form of counterfort walls. These types of retaining wall are built on the face of the wall and not within the backfill. Buttress walls are not too popular because of their buttressed shape exposed outside which consumes space and spoils the appearance.
5) Crib Retaining Wall:
The crib wall is shown in the figure. Crib walls consist of a series of boxes made from timber, precast concrete or steel members, which are filled with granular soils. It acts as a gravity wall with the advantage of a quick erection.
Crib walls can withstand large displacement of soil due to its flexible nature. It is usually fitted so that its face has a batter of 1 in 6. The width of the wall varies from 0.5 to 1.0 H and is suitable for walls up to a height of about 7.0 m. Note that the crib wall should not be subjected to surcharge loadings.
6) Gabion Retaining Wall:
These types of retaining wall constructed from rectangular metal cages or baskets. A gabion wall is made from a square grid of steel fabric, generally, 5 mm in diameter and spaced 75 mm apart. The gabion baskets are usually 2 m long and 1 m in cross-section. Each basket is provided with center diaphragm divides it into two equal 1 m 1 m sections and adds stability.
At the time of making stone-filled baskets are secured together with steel wire of 2.5 mm diameter. The base width of the gabion wall is about 0.5H. A typical wall is shown in figure. A good looking face can be provided by slightly stepping back each succeeding layer.
7) Sheet Pile Retaining Wall:
Sheet pile retaining walls are constructed from a series of interlocking piles individually driven into the foundation soil. Nowadays, modern sheet piles are constructed from steel, timber or precast concrete sections are also used.
Sometimes, a Cantilever sheet pile walls are held in the ground by the active and passive pressures that act on its lower part.
8) Anchored Earth Retaining Wall:
These types of retaining walls are fixed at the base and are supported by a row or two rows of ties or struts placed near its top.
9) Diaphragm Retaining Wall:
Diaphragm walls can be of a reinforced concrete wall or sheet pile wall. It includes a vertical concrete reinforced concrete slab fixed in position. Wall is held in position by the passive and active pressures acting on its lower portion.
10) Reinforced Earth Retaining Wall:
In this types of retaining wall the use of reinforcement to strengthen the soil has been known for centuries. In past straws are used to strengthen unburnt bricks and fascine mattresses have been used to strengthen soft soil deposits prior to road construction.
The main phenomenon working in reinforced earth wall is that a mass of soil can be given tensile strength in a specific direction if the lengths of a material capable of carrying tension are embedded within it in the required direction. Reinforced earth has been used in many geotechnical applications. Here, we are only concerned with retaining structures. A reinforced earth wall is a gravity structure.
What are the types of Retaining Walls?
Retaining Walls are broadly classified as follows:
1. Gravity Retaining Wall
2. Cantilever Retaining Wall
3. Counterfort Retaining Wall
4. Buttress Retaining Wall
5. Crib Retaining Wall
6. Gabion Retaining Wall
7. Sheet Pile Retaining Wall
8. Anchored Earth Retaining Wall
9. Diaphragm Retaining Wall
10. Reinforced Retaining Earth Wall
Q.2 What is Retaining Wall and its types?
Retaining walls are structures that are beneficial in retaining the surface of the ground at different elevations on either side of the structure by resisting the lateral pressure of the earth. Whereas its types are Gravity Retaining Wall, Cantilever Retaining Wall, Counterfort Retaining Wall, Crib Retaining Wall, etc.
Q.3 How many types of retaining walls are there?
Mainly there are 10 Types of Retaining Walls used to retain any type of earth component. They have been classified on the basics of the retaining structure, material used for retaining and its shape and size.
You May Also Like:
- Partition Wall and 12 Types of Partition Wall
- Parapet wall – 10 Types of parapet wall & Applications
- CMU Wall or Cinder Block Wall Construction, Size, Shape & Cost