GSP 131 Contemporary Issues in Foundation Engineering
Figure 1. Detail of a typical high capacity micropile.
Step 1: Feasibility
The cost effectiveness of micropiles will typically be limited to projects with one or more significant geological, structural, logistical, environmental, access or performance challenges. They are an especially favorable option where
The subsurface conditions are “difficult”, e.g., soils with boulders, or debris,
existing foundations, high groundwater.
There is restricted access and/or limited overhead clearance.
There are subsurface voids (e.g., karstic limestone).
Vibrations and noise must be limited.
Structural settlement must be minimized.
Relatively high unit loads (e.g., 500 to 5000 kN) are required.