What are the different structural types of retaining walls?
A number of residential homes are built on hills and slopes. And for a homeowner who considers having retaining walls for his yard, especially those needing to build medium to large walls, the services of a landscaping company may be required to ensure proper and secure installation.
There are several factors that should first be considered before working on retaining walls. It is crucial for the design to, specifically, cater the slope’s requirements in order to meet structural stabilization and balance. Among these factors are wall sizes, height, width, depth and ground pressure. Landscaping companies can help identify these factors and determine which design could best meet all your requirements.
Types of Retaining Walls
The following are five of the most common types of retaining walls used for residential landscaping:
Cantilever Retaining Walls
Sheet Pile Retaining Walls
Anchored Retaining Walls
Gravity walls are often appropriate for small retaining walls and are not usually built to exceed a height of four feet. This kind of retaining wall relies heavily on its weight in order to resist the pressure exerted by the materials behind it. Gravity walls do not necessarily require the services of a landscaping company to be built.
Gravity walls are built in a way that its base is thicker than its top and is often leaning backwards against the materials it is resisting. This inclination called “battering” makes the structure strong. However, the hillside force pushes the wall overtime, making the wall bulge outwards. This deformation shows that the wall is becoming unstable and needs to be reconstructed.
Although gravity walls are effective in restraining the earth, building these walls are somehow cumbersome. It does not only need to be thick at the base and require a huge amount of construction materials, but it also has to follow a certain ratio upon construction. The base needs to be one half to three fourths wide of its height. Therefore, the taller your walls are, the thinner it becomes. Hence, this structure is not effective for holding taller slopes.
2 - Cantilever Retaining Walls
Cantilever walls are single-layered walls built in uniform thickness with its base connected to a slab. These walls are capable of holding significant amount of earth and can support tall slopes.
The structure of the wall determines its strength and its capability to hold a significant amount of earth. However, the dimensions and the construction of the wall are quite complex. It is therefore a wise choice to hire the services of a landscaping company when constructing this kind of structure.
Cantilever walls require steel reinforcement in both its base and its surface. The steel support needs to extend from the base throughout the wall to ensure that both parts coordinate together. Furthermore, the construction of the base is extremely important. It needs to be designed in a way that it could resist the earth’s outward pressure. Proper engineering and construction is required to ensure that the wall could best serve its purpose.
3 - Sheet Pile Retaining Walls
Sheet pile retaining walls (also known as piling retaining wall) is a type of retaining wall that is usually utilized on soft soils with inadequate space for wide barriers. It usually employs the use of planks that are vinyl, steel, or wood that is pushed into the soil and is held up by soil on either side.
Usually, 2/3 of the material is hammered below the soil, and this could be adjusted depending on the landscape. In cases involving taller sheet pile retaining walls, a tieback anchor or “dead man” set up behind the wall’s surface is used to keep it in place. A cable is employed to bond the wall and the tieback anchor together. To ensure that the wall can withstand bending strengths of the earth behind it, the services of a landscaping company may be of significant help.
4 - Anchored Retaining Walls
Anchored retaining walls are similar to piling retaining walls in a way that it utilizes cables for added strength. These cables fasten the surface’s top and base together. The anchors are bored into the material and then expanded in the ground by mechanical means or by the aid of pressurized concrete that inflate into bulb shape. The cables help the wall resist pressure that could otherwise cause it to become unstable. Although this method appears to be technically complex, it is ideal however for supporting heavy loads.
5 - Counterfort Retaining Walls
This type of retaining wall is closely similar to cantilever walls, except it is built with the addition of thin vertical concrete webs (counterfort) installed at regular intervals along the rear side of the wall. These counterforts connect the wall’s top and the base together lessening shear forces and bending moments caused by the earth. This in turn, results in added strength.