There are several types of pressure grouting, each with a specific use and a different set of advantages. Understanding these types and how they can affect the soil underneath is important. In doing so, you can choose the best method for your situation.
What Is Pressure Grouting?
Pressure grouting is done by injecting grout or another compound into the ground or soil. It is used to fill voids, stabilize soil, level concrete, and even fix foundation issues. Many contractors utilize pressure grouting because it is effective yet low-cost, especially when compared to excavation or construction.
What Are the Types of Pressure Grouting?
There are five major pressure grouting types: permeation grouting, compaction grouting, jet grouting, rock or fissure grouting, and compensation grouting. Each of these types has its benefits and uses. Understanding the unique features and characteristics of each one will allow you to pick which method suits your needs best.
Here are the types of pressure grouting and what they’re for.
1. Permeation Grouting
With permeation grouting, grout is injected into the soil to fill voids without compromising the structure and volume of the soil itself. The grout permeates the granular soils, thereby forming a cemented mass.
Using permeation grouting to create barriers against water flow, offer excavation support, underpin foundations, and stabilize soils is best. You can use a few materials for permeation grouting, including bentonite and polyurethane foam.
The advantages of permeation grouting include:
- Usability in inaccessible areas
- More economical than other methods when underpinning foundations
- Application does not interfere with normal business operations
- May be used next to existing foundations
2. Compaction Grouting
Compaction grouting is another one of the grout injection methods available. This method uses thick grout, such as soil cement, to stabilize soils and improve load-bearing capacity.
Unlike permeation grouting, compaction grouting pushes the soil to compact it. It does not mix with or permeate the existing soil. Because of this, it is not compatible with low-permeability soils. Instead, it is suitable for loose granular soils, soluble rocks, and collapsible soils.
The advantages of compaction grouting include:
- Usability in inaccessible areas
- Does not generate a lot of vibration
- Completed in a short period
- Helps aid settling foundations
- Good for sinkholes
3. Jet Grouting
Jet grouting utilizes a high-velocity fluid jet to disrupt the soil physically. Once the soil is eroded, the grout is combined with the soil to improve it. It is best suited for underpinning structures and consolidating clay, sandy gravel, and soft foundations. Jet grouting is also good for soil stabilization, especially when groundwater control is necessary.
That said, jet grouting is not the first option that most people consider. This is because jet grouting is significantly more expensive than permeation grouting.
The advantages of jet grouting include:
- Works with a wide range of soil types
- Less working room is necessary
- Can treat deep soil layers without the need to treat soils above
- Application does not interfere with normal business operations
4. Rock or Fissure Grouting
Rock or fissure grouting involves injecting grout to fill fractures and fissures in a rock mass. This method should not create new fractures or worsen existing ones.
To apply this method, a contractor will drill a gap into the rock mass before injecting grout. The primary objective of rock grouting is to limit the flow of water in fissured rock joints.
The advantages of rock or fissure grouting include:
- Reduces the flow of groundwater
- Minimizes the deformation of rock masses
- Limits transmissivity through interconnected porous zones in aquifers
- Minimizes pumping costs when excavating basements
5. Compensation Grouting
Finally, compensation grouting involves the injection of cement slurry into the soil under high pressure. The grout then creates root-like formations within the soil. These formations help compact the surrounding soil and enhance density.
Also known as fracture grouting, this method works well for releveling structures, increasing load-bearing capacity, and filling voids.
The advantages of compensation grouting include:
- Allows for real-time monitoring of the grouting procedure as well as soil displacement
- Usability from tunnels or shafts underneath structures
The Best Course of Action
Pressure grouting is a good way to restabilize soil, fill gaps in the soil, and prevent erosion. However, application comes in more ways than one. As such, it is best to hire a professional who is familiar with the different types of pressure grouting. In doing so, you can avoid further complications.