A macropile is an ultra-high-capacity micropile typically drilled in place. Hayward Baker developed this technique as a solution to heavy loads in tight access sites.
- Provide structural support
Typically, a steel pipe is advanced using a drilling technique to the design depth. In cases where the drill hole remains open without casing, an open hole can be advanced to the bearing depth and the pipe installed after. Reinforcing steel in the form of all-thread bar or concentric pipes is inserted into the pipe. High-strength cement grout is then pumped into the pipe(s) by tremie. The pipe tip may be above the bond zone with the reinforcing steel extending full depth. The finished foundation element resists compressive, uplift, and lateral loads.