Micropile drilling is a commonly used on new and existing foundations that require additional ground support for the proposed structure. When a micropiles is drilled and installed into the substrate then fastened to the foundation the entire length of the pile is put under compression. The skin friction of the micropile assists in counteracting against the downward forces of the structure.
Micropiles are commonly installed with either permanent or temporary casing. The hole is drilled to depth with the assistance of casing to keep the hole from collapsing. The inner drill string is removed and either a rebar cage or an anchor tendon is placed into the cased hole. Grout is then added to the hole until fully encapsulated. If the casing is considered temporary it is removed leaving the grout and tendon behind. Once the pile is fully cured it is sometimes tested. This pile is often tied into a new footing or is fastened to the footing with a mechanical connection. Most micropiles tend to be between 100cm to 300cm in diameter and 4 to 30m in depth depending on the engineered specifications.
We at Norpac have installed all varieties of micropiles in some of the most challenging conditions. Often these piles are required in remote or limited access locations. We have available limited access drill rigs that can make their way into tight spots or flown in by helicopter. Whatever your need we would assuredly have a solution.