Micropiles are small diameter, typically 12 inches or less, deep foundation piles. Because they can be installed with relatively small drilling equipment, they are a cost effective foundation system in low overhead conditions such as inside existing buildings or under existing bridges. Schnabel has specialized drills that can even travel through a standard doorway and drill under an 8-foot ceiling height.
Micropiles are often used to underpin existing structures because they can be installed inside the structure and their installation produces less vibration than other deep foundation systems. Micropiles are also used is to construct deep foundations where there are natural or man-made obstructions since the drill systems developed for these smaller diameter holes are better able to penetrate cobbles, boulders and other obstructions than conventional drilled or driven pile systems. In the most difficult drilling conditions, such as within landslide debris, we have drilled micropiles and used them as soldier beams in permanent tieback wall construction. In difficult subsurface conditions and restricted access, micropiles can be a more cost effective solution for new structure construction. Schnabel has successfully installed and tested micropiles in compression to over 1,200 kips.