Prepared by
Dr. Mayadah W. Falah
1.1. Mechanically Stabilized Earth Components
The mechanically stabilized earth components consist of many components as
showed below (Morsy & Thakeb, 2022; Weldu et al., 2015):
Soil.
Geosynthetic Reinforcement (Geotextile or Geogrid).
Masonry Block Facing Units.
Drainage System.
Leveling Pad.
Figure shows the components of MSE wall.
1.2. Advantages of MSE walls
Advantages in terms of economy, ease of construction and rapid and speedy
construction with minimum disturbances to traffic and other services makes MSE
walls one of the most favorites and preferred retaining wall system. A variety of
materials and customization options in terms of design and construction made it one
of the most popular earth retaining system (Khan, 2014). The fascia elements, the
back-fill, and the reinforcing system combine to form a gravity retaining structure
that relies on the self-weight of the reinforced soil mass. This self-weight resists the
lateral pressure from the earth and the service loads, seismic loads, and hydro static
pressure (Lamis, n.d.; Morsy & Thakeb, 2022). The main advantages of MSE wall
including:
They can be designed to take extremely heavy loads like bridge abutment
footings, crane loads, service loads, etc.
MSE walls can resist seismic and dynamic forces and transfers the bearing
pressure to a wide area.
Faster construction than conventional retaining walls.
Less site preparation is required and can be constructed in confined areas
where other retaining walls are impossible to construct.
There are no supports, finishes and curing time.
The fascia walls are lightweight and are precast and conveyed to the site and
lifted using simple lifting equipment. These walls can be made to any height
and can resist unequal settlements.
They can be customized to any geometry and the construction process is very
simple. They do not need any heavy types of machinery and specialized
workers.
The fascia can be customized for designs and logos and gives superior and
elegant finished and aligned walls.
Any obstructions inside the back filled areas can be managed by adjusting the
angle of the reinforcing elements.
They possess a very good service life in extreme loading and complex
applications.
1.3. Disadvantages of MSE retaining walls.
MSE retaining walls require granular material in huge quantities. Areas where
there is a scarcity of granular material the construction cost increase and make
the structure uneconomical.
The corrosion of reinforcement and deterioration of geo-grids on exposed to
sunlight has to be addressed. The reinforced component must be designed to
withstand erosion and corrosion processes which can highly deteriorate the
mechanical behavior of the composite structure.
The granular back filling enables free drainage of water through the exposed
panel joints and reduces hydro static pressure.
A proper drainage system should be provided.
The wall must obtain a minimum width in order to acquire adequate stability.
1.4. Applications of Mechanically Stabilized Earth Walls
Mechanically stabilized earth barriers may be employed in a variety of scenarios,
depending on the location, including (Balunaini et al., 2009; Elias et al., 2001;
Sankey & Soliman, 2004):
Abutments for bridges.
Creating storage space.
At building locations with problematic soil.
In regions with a lot of earthquake activity.
Along the wings.
As temporary buildings during road construction.
Use as dams or structures for soil retention.
Around oil tanks as containment structures.
Walls of containment surrounding gas storage tanks.
Adding height to levees and building dams increases storage capacity