Earth Retention Structures
Holding Back the Earth
Not the planet…the Soil!
Earth retention structures and techniques are used in all sorts of circumstances, from your sloping rock garden in the backyard all the way up to industrial open-pit mining. It is essential in urban city centers.
The construction of skyscrapers, when side by side, has to deal with a great deal of interdependency. Any existing space between an established site and a demolition, renovation, or new construction, is subject to change when the adjacent soil is altered.
The buildings themselves are quite safe since they are supported on pilings driven deep into the bedrock. They are not going to fall over, even if you remove the soil from around their bases. They might face cracking in their underground parking or other utilities over time, so it is important to prevent that.
The biggest challenge, however, is that there are streets, pedestrian walkways, and other accesses, such as lanes or driveways, to enter different parts of the property. The white areas immediately surrounding the proposed (pink) excavation would collapse inwards without proper support.
What are Earth Retention Structures?
Earth retention is the practice of stabilizing soil and rock as a part of an excavation process. These piles are used to keep dirt in place during construction, which can be either permanent or temporary depending on needs for the site and the project’s ultimate intent. There are some tools available such as contiguous piles, soldier piles, ground anchors that may help with this matter; however, there is also reinforcement concrete designed to resist pressure from earth when needed.
Contiguous pile walls are exactly what they sound like, each pile next to the other. These are permanent earth retention structures. Minor spaces can be filled with shotcrete.
Soldier piles have been used since the 1700s, and are often used as temporary shoring because they are fast to install and easy to remove. They are placed about 6 to 12 feet apart, followed by excavation in stages, installing lagging, then backfilling the void behind the lagging.
Concrete Piles
Bored and poured (augured and filled) is sometimes called Continuous Flight Auguring (CFA) if the concrete is pumped directly through the hollow augur as it is removed. Upon extraction, a rebar cage is 
plunged into the concrete, all the way to the bottom (as much as 100 feet deep for this technique), or sometimes steel I-beams depending on the size and strength required. Pilings can be between 2 and 4 feet in diameter with CFA.
Vertical Faces
Rock Nails or Soil Nails (depending on the conditions around you) are an excellent (and quieter) alternative to using a pile-driver to place temporary wooden piles. As you dig incrementally deeper, you can retain the Earth by using its very own mass to hold it in place.
When this is a permanent installation, these ground anchors can release grout at different locations along its length to hold it in place. Those anchors will never come loose!
Non-Vertical Slopes
Sometimes an embankment is fairly stable and just needs a little support to make sure it doesn’t shift during construction, especially if large equipment will be moving on top of it. Such a geogrid mesh can be custom-shaped to make it more suitable to its environment, your needs, or simple aesthetics.
Of course, it can be removed when the work is done. If it is a permanent addition, the surface can be landscaped to suit.
Shotcrete in Earth Retention Structures
It could also be overlaid with Shotcrete. This is often done with watercourses, drainage systems, and levees.
When Shotcrete is used as shoring for an excavation, rebar is put in place, secured, and then the retaining wall is sprayed into place. It’s less expensive than concrete panels, much easier to shape according to need, and faster, too.
More: Shotcrete – A Versatile Tool
The Takeaway on Earth Retention Structures
Oscar Orduno, Inc. is all about you, your project, and the safety of both your’s and our workers all during construction. Our goal is always to minimize unnecessary disruption to your neighbors, other tradespeople, and people in the vicinity, and to operate in a manner to ensure the utmost protection to your structures and property. We pay attention to all the details, so when your earth retention structures are done you can be confident that they were done right!
We cover most of the state, including Dallas, Fort Worth, Austin, San Antonio, Houston, Lubbock, Amarillo, Tyler, and Waco. You’ll see our bright orange equipment in almost all of those places, and much more besides! We’d love to hear you say “Howdy,” so take a moment and get in touch.
Read more about our construction services here.
4600 Fuller Drive, Suite 375,
Irving, TX 75038
972-717-3070
For that occasion when you don’t want the earth to move!
