Bentonite Slurry Wall Purpose And Usage

By Author: William Hauselberg
Total Articles: 816
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Slurry walls are non-structural barriers used to build reinforced-concrete walls. They're most commonly used on sites where the earth is soft and likely to turn into soupy mud, which can disrupt the building process. Sites with a high water table, or those close to open water such as a lake or river are both good candidates for a slurry wall. This technique is common in tunnel-building projects, under and around dams, and for foundations in wet conditions.

Slurry Wall: A Wall That Isn't a Wall

The slurry wall isn't really a wall at all. It's actually a trench, usually dug to between one and a half and five feet deep, using a hydraulic excavator. This trench forms a barrier between the concrete work and the ground water. Some special slurry walls may be dug up to 100 feet deep, however using special cranes and other equipment. Slurry wall trenches should be situated in bedrock, clay, or other low permeability strata, to reduce the chances of leakage.

Once the trench has been dug to the correct depth, workers fill it with bentonite clay and water, which forms a thick barrier on the walls of the trench. Then, ...
... the trench is refilled with a mixture of dug out soil, dry bentonite clay, and wet bentonite slurry . This material should be mixed to about the same consistency as wet concrete, and should push the previous slurry back out of the trench. This produces the final soil bentonite slurry trench cut off wall .

Instead of using soil bentonite slurry trench cut off wall, it's also possible to fill the trench with concrete after the bentonite slurry is pumped away for recycling. This produces a solid concrete object underground, usually filled with metal tieback anchors that can be used to support the final concrete wall when the project is finished. This technique was used in the excavation of the World Trade Center site in New York City.

Small Scale Slurry

Originally developed in Europe, slurry walls are frequently used for small scale projects in the United States. This useful technique allows more efficient concrete wall construction in adverse environments, and prevents mud and water from swamping the project.

This a great infornmative article about bentonite slurry. The article well explains soil bentonite slurry trench cut off wall.