The term “Pressure Grouting” is in widespread use, but it is frequently misused. Although it seems to describe a specific type of grouting, the term is not specific. It refers to a wide variety of procedures. All grouting is done under pressure, so it is kind of like saying, “wet water”. Permeation Grouting is a more precise term for what is commonly referred to as pressure grouting.
Permeation grouting is the direct pressure injection of a fluid grout into the ground to fill the spaces between particles. It is a very flexible approach to ground improvement.