Micropiles are piles of small diameters, generally smaller than 30 cm executed with special technologies. They can be done within extremely small working space and in difficult working conditions, performed using special equipment of reduced dimensions, which cause no disturbance to the soil and or to the structures involved. Due to their versatility, the field of application is unlimited, and the high axial load, which they can take, is always comparatively much higher than any other types of pile.
FS Micropiles is a high-pressure injected micropile. Placing a steel tubular reinforcement into a borehole (unless the tubular reinforcement itself had been used for the boring, in which case the same is left in place) does it. The steel tubular reinforcement is generally made of special steel (high tensile strength) so as to be able to give high capacity to the piles. This tubular reinforcement is the main element of strength of the pile transversal section. Further, the high tensile steel pipes, provided with “manchettes” (or check valve) every 50 cm of length, are the indispensable means used to carry out the high pressure injections (the pressure injections are always controlled and mostly repeated or multi-stage for high bearing capacity micropiles).
Micropiles technology is similar to the one practiced many years for the soil impregnation by injections. It is also identical to the one used for the construction of some type of soil-rock anchors.
The difference between various types of FS pressure injected micropile is essentially the section of the steel tubular pile installed. The choice of FS Micropile sizes is dictated mostly by the need of using standard pipes and drilling tools, so that for every range of loads could be found tools for boring and tubular steel for reinforcement, with the desired characteristics, without having anything made on order with special sizes. The standardization is imposed both by economical and quality control reasons.