The principles of micropile engineering calculations are function of the it’s type and, consequently, it’s behavior. In a situation where micropiles are used to strengthen and improve foundation soil, technical calculations are similar to those of conventional piles. These calculations are based on three major parts of structural design, geotechnical design, and punch failure shear control.
In structural design, the bearing capacity of the micropile elements consists of a steel caisson, reinforcement bar and cement grout, which should have a good factor of safety about loads on the microporous.
In geotechnical design, the friction strength of the micropile is determined by the surrounding soil, which must be above the loads with a acceptable factor of safety so that it is not possible to separate the micropile from the soil prior to the reinforcement bar yield state.
In the final step of the design, due to large concentrated loads on micropiles have a and their small diameter, punch failure of bearing elements should control and proper flange design should be considered.