Design of Micropile Foundations

Micropiles are the most advantageous foundation type for new buildings, bridges and retrofit projects. A micropile is a six to twelve inch diameter drill hole reinforced with 75 to 150 ksi solid or hollow bar. Micropiles are designed as friction supported pile. The foundation length consists of unbonded upper portion that is often cased and bonded lower portion that is uncased and founded on deeper more competent soils. Several factors make a micropile foundation ideal. These include high capacity, tension capacity that is just as high as compression capacity, no vibrations from installation, limited overhead clearance not a concern, and ease of batter pile installation. Design considerations include shear strength of the soils or rock, determining unbond length, plunge depth, casing type, and other connection details. Foundation Engineering Consultants performs complete and economical design of micropile foundations.

We are part of the design build team, offering micropile prebid services.  This includes reviewing soils reports, determining bond length, bar size and grade, plunge depth, casing dimensions and unbond length.  We have worked on several prebids, and due to the competitive nature of such projects, a geostructural firm like ours can make the winning bid difference.