In the realm of soil improvement, jet grouting stands out as a pivotal technique. This process involves mixing soil in-situ with injected cement grout to create a cement-stabilized soil column. The resulting soil offers increased strength and reduced permeability, making it an ideal engineered solution for foundation support and groundwater control. Typical applications include underpinning existing structures and forming cutoff walls for excavation support.
This method involves drilling a small-diameter pipe, approximately 4 inches in diameter, to the desired depth. Contractors then inject cement grout at high pressures, around 6,000 psi, through the drill pipe. This grout mixes with the soil as the pipe rotates and withdraws, forming a circular column of improved soil. The diameter of these columns can be adjusted by altering the withdrawal speed, offering flexibility in the support structure. These columns can either provide vertical support individually or be arranged in a pattern to create a barrier against soil and water movement.