INFLUENCE OF EXECUTIVE VARIABLES ON THE
MECHANICAL BEHAVIOR OF SELF-DRILLING TUBULAR MICROPILES IN TROPICAL
SOIL.
Tube micropiles, tropical soil, foundations, porous soils.
This work aims to contribute to the knowledge of self-drilling tubular micropiles
installed in the soil of Brasilia. This pile is one of the “Cast-in-place” type and for its
molding a rotary drilling with simultaneous injection is used. Eight load tests were
carried out on isolated piles, varying the parameters of injection pressure, diameter and
length; and four other load tests in groups of two, three, four and five piles, all with the
same executive characteristics. The diameters analyzed for the isolated piles were 200
and 260 mm, and the diameter used for the group piles was 200 mm. The injection
pressures used were 200 kPa and 250 kPa for isolated piles and 200 kPa for group piles.
The length used for the isolated piles was 8 m and 12 m and for the group piles the
length was 8 m. The efficiency of the group of piles at 10% and 5% of settlement
normalized by diameter was also analyzed. It can be concluded from this work that the
adequate choice of the executive characteristics of the pile allows the optimization of
the foundation system. This type of pile proved to be a viable alternative for porous
soils with low resistance to penetration (Nspt) such as those in Brasilia, as it can offer
technical, economic and environmental advantages in relation to other types of piles,
mainly those related to their high execution speed and low cost.