Pressure GROUTING SOLUTIONS
Jet grouting, a specialized form of pressure grouting, involves the in-situ blending of soil with a cement grout to form a robust soil column. This process enhances the soil’s strength and reduces permeability, making it an engineered solution for foundation support and groundwater management. It’s particularly useful for underpinning existing structures and creating cutoff walls for excavation support.
The technique involves drilling a narrow pipe (about 4 inches in diameter) to the required depth, followed by injecting cement grout at high pressure (around 6,000 psi). This action, combined with the rotation and retraction of the pipe, forms a circular column of fortified soil. By adjusting the withdrawal speed, the diameter of these columns can be tailored. Strategically placed, these columns offer vertical support or combine to form a barrier against soil and water movement.

The effectiveness of jet grouting, a subset of pressure grouting, is heightened in areas with underground utilities or obstructions. The slender drilling pipe can navigate these spaces, allowing for the creation of wider soil columns beneath, an advantage not offered by traditional methods. This flexibility makes jet grouting a preferred choice for complex subsurface conditions.
AN INDISPENSABLE PARTNER FOR CLIENTS WITH COMPLEX PROJECTS THROUGHOUT THE UNITED STATES.
Children’s Hospital in Minneapolis
Schnabel used jet grout columns as underpinning and excavation support for the construction of an addition to the Children’s Hospital in Minneapolis, Minnesota. The jet grout columns eliminated the need for timber lagging and prevented the loss of sand during the 21-foot-deep excavation.
J Avenue Water Treatment Plant
Schnabel installed 67 jet grout columns to support the expansion of the J Avenue water treatment plant in Cedar Rapids, Iowa. This project required an excavation adjacent to an existing structure. The continuous wall of jet grout columns was successful in retaining the soil and water behind the wall and no measurable settlement of the tank structure occurred.