Fire Recovery Realities

When Chemical Grouting Is Appropriate For Your Project

by Matthew Fields

Chemical grouting is a process that can offer underpinning and support for buildings or structures on loose soil. The process requires training and knowledge of the soil as well as the grout, but when done correctly, it can be the best solution for stabilizing some types of soil. 

Understanding Chemical Grouting

Chemical grouting is the process of injecting a grout mixture into the ground to fill a void space with a material that will harden and support the ground or a structure sitting above the void. When done properly, the grout becomes extremely hard and is very much like sandstone in density. Chemical grouting is a good option for filling voids in an area that is inaccessible.

The Grouting Process

Before the grout can be injected into the void space, a hole is drilled into the void from the surface. A pipe is inserted into the bore and then grouted into place so it does not come out during the injection process.

Once the pipe is ready, the grout is injected under pressure into the void, until the empty space is full. The grout is effective for supporting a structure above it or for blocking groundwater so it can not run under a building or road, washing out the soil and causing problems later. 

Grouting can create a denser soil that will withstand tunneling or support excavation operations in areas that might be otherwise to unstable to dig in. Getting a representative from a chemical grouting company out to your site is the first step in determining if the process can work for your situation.

Monitoring and Potential Problems

When chemical grouting is used to fill a void, it is critical that the grout does not overfill the void. The company injecting the grout needs to closely monitor the pressure they are using during the injection process so that the grout does not cause soil displacement.

Injecting grout underneath a structure without proper monitoring could cause the soil under the structure to rise and may damage the foundation or cause the structure to twist or rack. The result may be a bigger issue than the problems you had before the grouting began and could cause structural damage that is not easily repairable. 

Once the grout is injected into the ground, it can not be removed. If the technician is not being very cautious, the entire project can be put in jeopardy, so it is critical to check out the company you are working with before the work starts. 

For more information on chemical grouting, contact a company in your area like A-PAC Pressure Grouting Inc.