Abstract

Micropiles are known to be small in diameter (maximum 300 mm), replacement piles, drilled, composed of placed or injected grout under pressure. This study presents a critical review of the existing design methods and examines the parameters governing the design of these piles. Furthermore, a design procedure is proposed to take into account the geometry of the micropiles, the interaction with the soil and to incorporate the parameters, which seemed to be ignored in the previous methods. The proposed designed procedure was validated against field tests, where good agreement could be found. Numerical models were developed using the finite element technique to provide solutions for the case stated. The first model was to simulate the installation techniques of the micropiles and to perform a parametric study. The second numerical model was to simulate the cavity expansion caused by grouting pressure and to develop the relationships of pressure versus expansion of the pile diameter, length of expansion and soil properties. (Abstract shortened by UMI.)