Grouting is the process of filling voids (contact grouting), and filling the annular space between pipes with a sealing material called grout. Grout is usually a cement or bentonite mixture that can be injected into the appropriate location, where it hardens.

Annular Space Grouting

Annular space grouting is used to fill the area between casing pipe and the carrier pipe. The decision whether or not to use grouting should be part of the design process for any project. If grouting is to be used, the costs in terms of time and money can be included in the initial planning.

In order to choose the correct grout and grouting technique, it is necessary to know:

• Size of the annular space to be grouted
• Initial pipe support
• Strength of the pipe
• Surrounding soil conditions and presence of ground water
• Type of spacers used
• Grouting pressure limits for the type of pipe used
• Unit weight of the grout
• Distance between bulkheads

Annular space grouting is done to:

• Seal pipe to prevent the entrance of water and soil
• Provide even transfer of external loads
• Prevent the collapse of a defective sewer pipe

Contact Grouting

Contact grouting is the process of filling the excavated space between a carrier pipe and the surrounding ground and any voids encountered when installing the carrier pipe.

The decision to use contact grouting should be included in the design process for the tunneling project. Some of the factors that affect the decision to use contact grouting include:

• Geotechnical data (ground water conditions and type of soil)
• How deep below the surface the installation will be
• Diameter of the excavation
• The trenchless tunneling method used
• Type of casing and carrier pipe materials
• Heaving and settlement concerns
• Purpose of the trenchless installation (used for: water supply, sanitary sewer, storm sewer, oil, gas, electrical or communication lines)

Accurate geotechnical data and careful design planning ensure a successful contact grouting procedure.

J & J Boring, Inc., Staying Current Since 1983

From our inception, J & J Boring, Inc. has delivered efficient, quality service to our clients. Our crews are up-to-date on the latest information in trenchless tunneling methods and procedures.

We work with contractors and engineers to provide the most cost effective methods of completing tunneling projects. Call us at 636-566-6766 for a quote on your trenchless tunneling project.