Retaining walls are built to contain the soil that rests behind them. However, needs may vary. These walls are also practical and eye-catching additions to any home or businesses’ landscaping. When designing and building one, there are several factors that come into play.
One of the most important considerations is the types of retaining walls. Wondering how to choose a retaining wall material? Read on to discover the advantages and disadvantages of MSE vs Precast Modular vs Segmental Block retaining walls.
MSE (Mechanically Stabilized Earth)
MSE stands for mechanically stabilized earth. These are composite structures with altering layers of soil reinforcement elements and compacted backfill. These elements are then fixed to a wall facing which is relatively thin. Its function is mostly related to the protection of the structure and erosion.
The stability of these types of retaining walls is derived from the friction and tension involved with the soil reinforcements and compacted backfill. These structures can carry heavy loads and are considered a coherent gravity structure.
There are plenty of advantages when it comes to MSE. One of the most apparent of these includes its stability and strength. Its bearing pressure is spread out over a very wide foundational area.
MSE walls have the ability to accommodate extreme loads such as cranes and bridge abutment footings. In addition to their load-bearing, they have great strength to stand up against seismic and other dynamic forces.
This type of retaining wall is also very versatile. They can be built to incredibly large wall heights and special design allows for nearly any geometry. Aesthetically speaking, they can be customized to be quite appealing with murals or other materials.
Other advantages include:
- Free-draining because of granular backfill with open panel joints
- Rapid construction with predictable and repetitive processes
- Elite finished wall alignment
- Flexibility enough to accommodate several feet of the total settlement
While there are plenty of great things about MSE, there are some drawbacks to consider. The most obvious being the needed space. These walls require a relatively large area behind the wall to ensure internal and external stability is achieved.
Another consideration when speaking on MSE is the amount of granular fill needed. Depending on the area, there may not be a lot of this available. In such a case, you would need to import it to the location. This could exponentially raise the price of construction.
Finally, processes relating to these structures are still evolving. This means that there is no standardization for this structure. Suitable design criteria are also required to assess deterioration and corrosion of materials.
A precast modular retaining wall is a variation of a cantilever stem wall. Facing units that have been precast are secured into a precast or cast-in-place footing. Instead of designing the whole length of the facing stem to resist the Earth’s lateral pressure, there are one or two counterforts on the backside.
These counterforts act as the cantilever beams that resist the aforementioned lateral pressure. This allows there to be a thin wall facing between them and for a more efficient footing design. This variation increased the material efficiency of the traditional cantilever system.
This variation is a conventional and economical choice, especially when compared to that of the traditional cantilever system design. There is much less cast-in-place work to be done as well.
A large advantage of the precast modular type is the quick construction speed which causes no dip in quality. In addition, they are also incredibly versatile. However, they do best in scenarios with narrow cut applications and extreme utility obstruction.
There is also a lot of uniformity in precast concrete because of the same molds being used. In the end, this means quality is relatively consistent.
Where precast modular walls have disadvantages are mostly in the area of modification. In situations where the precast material doesn’t fit, special pieces will need to be ordered. This can cost significantly more money and time.
Moving precast concrete to a job site can be a difficult task. Damage can be done to trucks that are not equipped to handle the weight. Plus, materials must be kept very stable to ensure that no damage is done. Due to this, special transportation vehicles are usually required.
Once these materials arrive at a job site, they are just as equally hard to install as they are to transport. Again, due to the weight of these items mobile cranes are necessary.
Segmental block retaining walls have a facing and lateral tieback system. The facing system most often includes modular concrete blocks. These blocks interlock with one another and the lateral restraining members.
Lateral tiebacks are geogrids, a type of reinforcement, that are buried in the backfill. They stabilize the supporting wall and the soil behind the wall.
These types of retaining walls are used to hold back soil at a sloping face and create a vertical front. These walls have the ability to include stairs, curves, and corners.
Most commonly these walls are used in scenarios where you would like to widen an area that would naturally not be usable due to sloping of the land. These are also used for grade changes and functional reasons.
There are several advantages to segmental block retaining walls. The concrete footing necessary for other retaining walls is not required, making the construction process a bit easier. Gravel padding is enough to set the foundation.
These walls are also very versatile. They can be constructed in a wide variety of colors, textures, and sizes. In addition, they can include horizontal and vertical curvatures and offer easy grade changes.
Structures like this can be constructed very quickly as well.
Segmental block retaining walls can be quite labor-intensive. For a wall to be done correctly and be as sturdy as possible, the contractor needs to possess the proper skills.
These types of walls are not ideal for every situation. They’re versatile in design by not necessary in certain situations.
Choose Slaton Bros for All Your Retaining Wall Needs, Today!
Now that you know the differences when it comes to MSE, Precast Modular, and Segmental Block retaining walls, you can make the best decision for your situation. There are other variations of retaining walls but these are some of the most common.
If you need help constructing a retaining wall, contact us today for our specialty services!