Franki Piles, also known as Pressure Injected Footings (PIFS), are high-capacity, cast-in-place elements constructed using a drop weight and casing. Our Providence, RI office is available to design and construct Franki piles throughout the US.

Common Uses

  • Provide structural support

Technical Details

A 2 to 3-foot diameter steel casing is vertically positioned at a planned PIF location. The bottom 3 to 5 feet of the casing is filled with a very dry concrete mix. A steel cylinder with a diameter slightly smaller than the casing is then repeatedly dropped inside the casing on the dry mix. The mix locks into the bottom of the casing and the repeated blows of the drop weight advance the casing to the design depth. The casing is then restrained from further advancement and additional weight drops eject the dry mix out of the bottom of the casing. Additional dry mix is added and driven from the casing until a design resistance to further displacement is achieved. Reinforcing steel and concrete are then placed in the casing and the casing is removed. The finished foundation element resists compressive, uplift, and lateral loads.