Micropiles are the largest and fastest growing deep foundation application. This technology was first developed in Italy in the 1950s. The foundation of many of Italy’s historic structures were in urgent need of repair to meet modern code requirements. Conventional pile systems were generally not feasible, because they require more open area for installation than was often available. This unique combination of engineering challenges eventually gave birth to the micropile.

There are numerous variations of a micropile. In general, micropiles are high-capacity, small-diameter steel casing that is drilled into place, reinforced with an internal structural bar, and pressure grouted. The grout creates a bond between the interior casing wall and structural bar, as well as the external casing wall and the soil. Micropiles can also be installed in threaded short lengths when low head room access issues exist. These piles are designed to meet torque, tension, compression, and bending stresses.