If the soil body on a construction site is to be consolidated, high-pressure injection is often used. This is a procedure that requires the removal of a large amount of cement suspension - which quickly causes many pumps to fail.
This was the experience of a construction crew in Cologne, Germany, who wanted to use the soil grouting method to grout the floor. They relied on cantilever pumps to remove the liquid residues. This was a wise decision, because such pumps are quite suitable for swampy applications with high solids content and low immersion depths. In special civil engineering, however, they quickly reach their limits. In the case described, the pumps lasted only a few weeks. The highly abrasive pumping medium was so hard on them that a more economical solution had to be found.
In the process, also known as jetting, the soil is mixed with a binding agent, usually a cement suspension, under high pressure until a solidified soil mass is produced. It is used for deep foundations, underpinning or sealing bases for sheet piles. At several hundred bars of pressure, the self-hardening binder shoots out of the drill pipe into the working area. Loosened soil pushes to the surface with the excess cement suspension and must be removed. The resulting volume is considerable and amounts to several times the worked soil space.
