Geotechnical Engineers: Foundation Problem Solvers
Date Posted: April 19, 2022
Posted In: Workforce,
by Bradley Gardner, Burns & McDonnell
All structures rely on a solid foundation, and an in-depth understanding of what lies beneath the earth’s surface — whether it’s rock or soil — is essential. Such insight helps inform decisions on foundation types and materials that are best suited for a project.
Understanding a Structure’s Foundation Needs
A key step during a project’s inception is a site evaluation overseen by a geotechnical engineering team to consider the site’s subsurface conditions, strength characteristics and physical properties. That’s because not all foundation types are suitable for all locations. Working closely with a project’s structural engineers, the geotechnical team may recommend shallow foundations or deep foundations such as drilled shafts, micropiles, drilled piles or helical piles. Helical piles are prefabricated foundations composed of steel pipes that have welded helix-shaped plates configured along their shafts. The piles are screwed into the soil to a targeted installation torque value and design depth, where the load is then transferred from the pile to the soil along the shaft and through the helical plates.
Compared to concrete drilled shaft foundations, helical piles offer several advantages, including:
- Better quality control.
- Reduced labor demands.
- Compact installation equipment.
- Verification of axial capacity using a torque-to-capacity relationship.
- Faster installation.
- Fewer environmental risks.